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Calculations of hadronic weak matrix elements: A status report
International Nuclear Information System (INIS)
Sharpe, S.R.
I review the calculations of hadronic matrix elements of the weak Hamiltonian. My major emphasis is on lattice calculations. I discuss the application to weak decay constants (f/sub K/, f/sub D/, f/sub B/), K 0 /minus/ /bar K/sup 0// and B 0 /minus/ /bar B/sup 0// mixing, K → ππ decays, and the CP violation parameters ε and ε'. I close with speculations on future progress. 57 refs., 4 figs., 2 tabs
Weak matrix elements efforts on the lattice: Status and prospects
International Nuclear Information System (INIS)
Soni, A.
Lattice approach to weak matrix elements is reviewed. Recent progress in treating heavy quarks on the lattice is briefly discussed. Illustrative sample of results obtained so far is given. Among them I elaborate on B K , line-integral B and B → K* γ . Experimental implications especially with regard to constraints on the Standard Model (i.e. Wolfenstein) parameters, V td measurements and expectations for B s -bar B s , oscillations are briefly discussed
Weak matrix elements on the lattice - Circa 1995
International Nuclear Information System (INIS)
Soni, A.
Status of weak matrix elements is reviewed. In particular, e'/e, B → K*γ, B B and B B , are discussed and the overall situation with respect to the lattice effort and some of its phenomenological implications are summarised. For e'/e the need for the relevant matrix elements is stressed in view of the forthcoming improved experiments. For some of the operators, (e.g. O 6 ), even bound on their matrix elements would be very helpful. On B → K degrees γ, a constant behavior of T 2 appears disfavored although dependence of T 2 could, of course, be milder than a simple pole. Improved data is badly needed to settle this important issue firmly, especially in view of its ramification for extractions of V td from B → ργ. On B κ , the preliminary result from JLQCD appears to contradict Sharpe et al. JLQCD data seems to fit very well to linear α dependence and leads to an appreciably lower value of B κ . Four studies of B κ in the open-quotes fullclose quotes (n f = 2) theory indicate very little quenching effects on B κ ; the full theory value seems to be just a little less than the quenched result. Based on expectations from HQET, analysis of B-parameter (B h ell) for the heavy-light mesons via B h ell) = constant + constants'/m h ell is suggested. A summary of an illustrative sample of hadron matrix elements is given and constraints on CKM parameters (e.g. V td /V ts , on the unitarity triangle and on x s /x d , emerging from the lattice calculations along with experimental results are briefly discussed. In quite a few cases, for the first time, some indication of quenching errors on weak matrix elements are now becoming available
Primitivity and weak distributivity in near rings and matrix near rings
International Nuclear Information System (INIS)
Abbasi, S.J.
This paper shows the structure of matrix near ring constructed over a weakly distributive and primative near ring. It is proved that a weakly distributive primitive near ring is a ring and the matrix near rings constructed over it is also a bag. (author). 14 refs
Heavy-Quark Effective Theory and Weak Matrix Elements
Neubert, Matthias
Recent developments in the theory of weak decays of heavy flavours are reviewed. Applications to exclusive semileptonic B decays, the semileptonic branching ratio and charm counting, beauty lifetimes, and hadronic B decays are discussed.
Strong, Weak and Branching Bisimulation for Transition Systems and Markov Reward Chains: A Unifying Matrix Approach
Directory of Open Access Journals (Sweden)
Nikola Trčka
Full Text Available We first study labeled transition systems with explicit successful termination. We establish the notions of strong, weak, and branching bisimulation in terms of boolean matrix theory, introducing thus a novel and powerful algebraic apparatus. Next we consider Markov reward chains which are standardly presented in real matrix theory. By interpreting the obtained matrix conditions for bisimulations in this setting, we automatically obtain the definitions of strong, weak, and branching bisimulation for Markov reward chains. The obtained strong and weak bisimulations are shown to coincide with some existing notions, while the obtained branching bisimulation is new, but its usefulness is questionable.
Bag-model matrix elements of the parity-violating weak hamiltonian for charmed baryons
International Nuclear Information System (INIS)
Ebert, D.; Kallies, W.
Baryon matrix elements of the parity-violating part of the charmchanging weak Hamiltonian might be significant and comparable with those of the parity-conserving one due to large symmetry breaking. Expression for these new matrix elements by using the MIT-bag model are derived and their implications on earlier calculations of nonleptonic charmed-baryon decays are estimated
Method and apparatus for evaluating structural weakness in polymer matrix composites
Wachter, Eric A.; Fisher, Walter G.
A method and apparatus for evaluating structural weaknesses in polymer matrix composites is described. An object to be studied is illuminated with laser radiation and fluorescence emanating therefrom is collected and filtered. The fluorescence is then imaged and the image is studied to determine fluorescence intensity over the surface of the object being studied and the wavelength of maximum fluorescent intensity. Such images provide a map of the structural integrity of the part being studied and weaknesses, particularly weaknesses created by exposure of the object to heat, are readily visible in the image.
Strong, weak and branching bisimulation for transition systems and Markov reward chains: A unifying matrix approach
Trcka, N.; Andova, S.; McIver, A.; D'Argenio, P.; Cuijpers, P.J.L.; Markovski, J.; Morgan, C.; Núñez, M.
We first study labeled transition systems with explicit successful termination. We establish the notions of strong, weak, and branching bisimulation in terms of boolean matrix theory, introducing thus a novel and powerful algebraic apparatus. Next we consider Markov reward chains which are
Acceleration of criticality analysis solution convergence by matrix eigenvector for a system with weak neutron interaction
Energy Technology Data Exchange (ETDEWEB)
Nomura, Yasushi; Takada, Tomoyuki; Kuroishi, Takeshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Kadotani, Hiroyuki [Shizuoka Sangyo Univ., Iwata, Shizuoka (Japan)
In the case of Monte Carlo calculation to obtain a neutron multiplication factor for a system of weak neutron interaction, there might be some problems concerning convergence of the solution. Concerning this difficulty in the computer code calculations, theoretical derivation was made from the general neutron transport equation and consideration was given for acceleration of solution convergence by using the matrix eigenvector in this report. Accordingly, matrix eigenvector calculation scheme was incorporated together with procedure to make acceleration of convergence into the continuous energy Monte Carlo code MCNP. Furthermore, effectiveness of acceleration of solution convergence by matrix eigenvector was ascertained with the results obtained by applying to the two OECD/NEA criticality analysis benchmark problems. (author)
Microscopic universality of complex matrix model correlation functions at weak non-Hermiticity
International Nuclear Information System (INIS)
Akemann, G.
The microscopic correlation functions of non-chiral random matrix models with complex eigenvalues are analyzed for a wide class of non-Gaussian measures. In the large-N limit of weak non-Hermiticity, where N is the size of the complex matrices, we can prove that all k-point correlation functions including an arbitrary number of Dirac mass terms are universal close to the origin. To this aim we establish the universality of the asymptotics of orthogonal polynomials in the complex plane. The universality of the correlation functions then follows from that of the kernel of orthogonal polynomials and a mapping of massive to massless correlators
Lattice calculation of hadronic weak matrix elements: the ΔI = 1/2 rule
International Nuclear Information System (INIS)
Bernard, C.
A lattice Monte Carlo technique for calculating the matrix elements of weak operators is described. Emphasis is placed on the ΔI = 1/2 rule, which is such a large effect that the significant errors associated with current lattice methods (statistics, finite size, finite lattice spacing, extrapolations in quark mass, etc.) should not disguise the important qualitative features. A detailed exposition of the analytic bases for the calculation is given, and an attempt is made to avoid the questionable phenomenological assumptions (such as some of those inherent in the Penguin approach) which were necessary when matrix elements could not be calculated. The current state of the calculation-in-progress is described. This work is being done in collaboration with A. Soni, T. Draper, G. Hockney, and M. Rushton
New approach to nonleptonic weak interactions. I. Derivation of asymptotic selection rules for the two-particle weak ground-state-hadron matrix elements
International Nuclear Information System (INIS)
Tanuma, T.; Oneda, S.; Terasaki, K.
A new approach to nonleptonic weak interactions is presented. It is argued that the presence and violation of the Vertical BarΔIVertical Bar = 1/2 rule as well as those of the quark-line selection rules can be explained in a unified way, along with other fundamental physical quantities [such as the value of g/sub A/(0) and the smallness of the isoscalar nucleon magnetic moments], in terms of a single dynamical asymptotic ansatz imposed at the level of observable hadrons. The ansatz prescribes a way in which asymptotic flavor SU(N) symmetry is secured levelwise for a certain class of chiral algebras in the standard QCD model. It yields severe asymptotic constraints upon the two-particle hadronic matrix elements of nonleptonic weak Hamiltonians as well as QCD currents and their charges. It produces for weak matrix elements the asymptotic Vertical BarΔIVertical Bar = 1/2 rule and its charm counterpart for the ground-state hadrons, while for strong matrix elements quark-line-like approximate selection rules. However, for the less important weak two-particle vertices involving higher excited states, the Vertical BarΔIVertical Bar = 1/2 rule and its charm counterpart are in general violated, providing us with an explicit source of the violation of these selection rules in physical processes
Mass matrices of weak interaction, quark flavour mixing and exponential form of Cabibbo-Kobayashi-Maskawa matrix
International Nuclear Information System (INIS)
Dattoli, G.; Torre, A.
The quark mixing matrix is diagonalized. The use of the exponential parametrization leads to straightforward results, obtained in exact form, without simplifying assumptions. In this study, it is defined weak interaction eigenstates in the sense of Fritzch and Planckl. The relevant mass matrices are derived and are shown to belong to Barnhill canonical forms. It is proven that, at lowest order, these matrices exhibit a democratic structure. The mechanism of democracy breaking is finally discussed
The scattering matrix is non-trivial for weakly coupled P(phi)2 models
International Nuclear Information System (INIS)
Osterwalder, K.; Seneor, R.
It is shown that for sufficiently small coupling constant lambda the lambdaP(phi) 2 quantum field theory models have a scattering matrix which is different from 1. The other method is to write the scattering matrix elements as polynomials in lambda, whose coefficients, though themselves functions of lamda, are uniformly bounded for lambda sufficiently small. The first order term in that expansion is the one given by perturbation theory. (Auth.)
Non-negative Matrix Factorization for Self-calibration of Photometric Redshift Scatter in Weak-lensing Surveys
Energy Technology Data Exchange (ETDEWEB)
Zhang, Le; Yu, Yu; Zhang, Pengjie, E-mail: firstname.lastname@example.com [Department of Astronomy, Shanghai Jiao Tong University, Shanghai, 200240 (China)
Photo- z error is one of the major sources of systematics degrading the accuracy of weak-lensing cosmological inferences. Zhang et al. proposed a self-calibration method combining galaxy–galaxy correlations and galaxy–shear correlations between different photo- z bins. Fisher matrix analysis shows that it can determine the rate of photo- z outliers at a level of 0.01%–1% merely using photometric data and do not rely on any prior knowledge. In this paper, we develop a new algorithm to implement this method by solving a constrained nonlinear optimization problem arising in the self-calibration process. Based on the techniques of fixed-point iteration and non-negative matrix factorization, the proposed algorithm can efficiently and robustly reconstruct the scattering probabilities between the true- z and photo- z bins. The algorithm has been tested extensively by applying it to mock data from simulated stage IV weak-lensing projects. We find that the algorithm provides a successful recovery of the scatter rates at the level of 0.01%–1%, and the true mean redshifts of photo- z bins at the level of 0.001, which may satisfy the requirements in future lensing surveys.
Could a Weak Coupling Massless SU(5) Theory Underly the Standard Model S-Matrix
White, Alan R.
The unitary Critical Pomeron connects to a unique massless left-handed SU(5) theory that, remarkably, might provide an unconventional underlying unification for the Standard Model. Multi-regge theory suggests the existence of a bound-state high-energy S-Matrix that replicates Standard Model states and interactions via massless fermion anomaly dynamics. Configurations of anomalous wee gauge boson reggeons play a vacuum-like role. All particles, including neutrinos, are bound-states with dynamical masses (there is no Higgs field) that are formed (in part) by anomaly poles. The contributing zero-momentum chirality transitions break the SU(5) symmetry to vector SU(3)⊗U(1) in the S-Matrix. The high-energy interactions are vector reggeon exchanges accompanied by wee boson sums (odd-signature for the strong interaction and even-signature for the electroweak interaction) that strongly enhance couplings. The very small SU(5) coupling, αQUD ≲ 1/120, should be reflected in small (Majorana) neutrino masses. A color sextet quark sector, still to be discovered, produces both Dark Matter and Electroweak Symmetry Breaking. Anomaly color factors imply this sector could be produced at the LHC with large cross-sections, and would be definitively identified in double pomeron processes.
The effect of weak interface on transverse properties of a ceramic matrix composite
Shimansky, R. A.; Hahn, H. T.; Salamon, N. J.
Experimental studies conducted at NASA Lewis on SiC reaction-bonded Si3N4 composite system showed that transverse stiffness and strength were much lower than those predicted from existing analytical models based on good interfacial bonding. It was believed that weakened interfaces were responsible for the decrease in tranverse properties. To support this claim, a two-dimensional FEM analysis was performed for a transverse representative volume element. Specifically, the effect of fiber/matrix displacement compatibility at the interface was studied under both tensile and compressive transverse loadings. Interface debonding was represented using active gap elements connecting the fiber and matrix. The analyses show that the transverse tensile strength and stiffness are best predicted when a debonded interface is assumed for the composite. In fact, the measured properties can be predicted by simply replacing the fibers by voids. Thus, it is found that little or no interfacial bonding exists in the composite, and that an elastic analysis can predict the transverse stiffness and strength.
International Nuclear Information System (INIS)
Sato, Masanori; Matsubara, Takahiko; Takada, Masahiro; Hamana, Takashi
Using 1000 ray-tracing simulations for a Λ-dominated cold dark model in Sato et al., we study the covariance matrix of cosmic shear correlation functions, which is the standard statistics used in previous measurements. The shear correlation function of a particular separation angle is affected by Fourier modes over a wide range of multipoles, even beyond a survey area, which complicates the analysis of the covariance matrix. To overcome such obstacles we first construct Gaussian shear simulations from the 1000 realizations and then use the Gaussian simulations to disentangle the Gaussian covariance contribution to the covariance matrix we measured from the original simulations. We found that an analytical formula of Gaussian covariance overestimates the covariance amplitudes due to an effect of the finite survey area. Furthermore, the clean separation of the Gaussian covariance allows us to examine the non-Gaussian covariance contributions as a function of separation angles and source redshifts. For upcoming surveys with typical source redshifts of z s = 0.6 and 1.0, the non-Gaussian contribution to the diagonal covariance components at 1 arcmin scales is greater than the Gaussian contribution by a factor of 20 and 10, respectively. Predictions based on the halo model qualitatively well reproduce the simulation results, however show a sizable disagreement in the covariance amplitudes. By combining these simulation results we develop a fitting formula to the covariance matrix for a survey with arbitrary area coverage, taking into account effects of the finiteness of survey area on the Gaussian covariance.
Bounds on the number of bound states in the transfer matrix spectrum for some weakly correlated lattice models
International Nuclear Information System (INIS)
O'Carroll, Michael
We consider the interaction of particles in weakly correlated lattice quantum field theories. In the imaginary time functional integral formulation of these theories there is a relative coordinate lattice Schroedinger operator H which approximately describes the interaction of these particles. Scalar and vector spin, QCD and Gross-Neveu models are included in these theories. In the weakly correlated regime H=H o +W where H o =−γΔ l , 0 l is the d-dimensional lattice Laplacian: γ=β, the inverse temperature for spin systems and γ=κ 3 where κ is the hopping parameter for QCD. W is a self-adjoint potential operator which may have non-local contributions but obeys the bound ‖W(x, y)‖⩽cexp ( −a(‖x‖+‖y‖)), a large: exp−a=β/β o (1/2) (κ/κ o ) for spin (QCD) models. H o , W, and H act in l 2 (Z d ), d⩾ 1. The spectrum of H below zero is known to be discrete and we obtain bounds on the number of states below zero. This number depends on the short range properties of W, i.e., the long range tail does not increase the number of states.
Weak cation exchange magnetic beads coupled with matrix-assisted laser desorption ionization-time of flight-mass spectrometry in screening serum protein markers in osteopenia.
He, Wei-Tao; Liang, Bo-Cheng; Shi, Zhen-Yu; Li, Xu-Yun; Li, Chun-Wen; Shi, Xiao-Lin
The present study aimed at investigating the weak cation magnetic separation technology and matrix-assisted laser desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS) in screening serum protein markers of osteopenia from ten postmenopausal women and ten postmenopausal women without osteopenia as control group, to find a new method for screening biomarkers and establishing a diagnostic model for primary type I osteoporosis. Serum samples were collected from postmenopausal women with osteopenia and postmenopausal women with normal bone mass. Proteins were extracted from serum samples by weak cation exchange magnetic beads technology, and mass spectra acquisition was done by MALDI-TOF-MS. The visualization and comparison of data sets, statistical peak evaluation, model recognition, and discovery of biomarker candidates were handled by the proteinchip data analysis system software(ZJU-PDAS). The diagnostic models were established using genetic arithmetic based support vector machine (SVM). The SVM result with the highest Youden Index was selected as the model. Combinatorial Peaks having the highest accuracy in distinguishing different samples were selected as potential biomarker. From the two group serum samples, a total of 133 differential features were selected. Ten features with significant intensity differences were screened. In the pair-wise comparisons, processing of MALDI-TOF spectra resulted in the identification of ten differential features between postmenopausal women with osteopenia and postmenopausal women with normal bone mass. The difference of features by Youden index showed that the highest features had a mass to charge ratio of 1699 and 3038 Da. A diagnosis model was established with these two peaks as the candidate marker, and the specificity of the model is 100 %, the sensitivity was 90 % by leave-one-out cross validation test. The two groups of specimens in SVM results on the scatter plot could be clearly distinguished. The peak
International Nuclear Information System (INIS)
Leite Lopes, J.
A survey of the fundamental ideas on weak currents such as CVC and PCAC and a presentation of the Cabibbo current and the neutral weak currents according to the Salam-Weinberg model and the Glashow-Iliopoulos-Miami model are given [fr
International Nuclear Information System (INIS)
Wojcicki, S.
Lectures are given on weak decays from a phenomenological point of view, emphasizing new results and ideas and the relation of recent results to the new standard theoretical model. The general framework within which the weak decay is viewed and relevant fundamental questions, weak decays of noncharmed hadrons, decays of muons and the tau, and the decays of charmed particles are covered. Limitation is made to the discussion of those topics that either have received recent experimental attention or are relevant to the new physics. (JFP) 178 references
International Nuclear Information System (INIS)
Ogava, S.; Savada, S.; Nakagava, M.
The problem of the use of weak interaction laws to study models of elementary particles is discussed. The most typical examples of weak interaction is beta-decay of nucleons and muons. Beta-interaction is presented by quark currents in the form of universal interaction of the V-A type. Universality of weak interactions is well confirmed using as examples e- and μ-channels of pion decay. Hypothesis on partial preservation of axial current is applicable to the analysis of processes with pion participation. In the framework of the model with four flavours lepton decays of hadrons are considered. Weak interaction without lepton participation are also considered. Properties of neutral currents are described briefly
International Nuclear Information System (INIS)
Chanda, R.
The theoretical and experimental evidences to form a basis for Lagrangian Quantum field theory for Weak Interactions are discussed. In this context, gauge invariance aspects of such interactions are showed. (L.C.) [pt
International Nuclear Information System (INIS)
Bjorken, J.D.
Weak interactions are studied from a phenomenological point of view, by using a minimal number of theoretical hypotheses. Charged-current phenomenology, and then neutral-current phenomenology are discussed. This all is described in terms of a global SU(2) symmetry plus an electromagnetic correction. The intermediate-boson hypothesis is introduced and lower bounds on the range of the weak force are inferred. This phenomenology does not yet reconstruct all the predictions of the conventional SU(2)xU(1) gauge theory. To do that requires an additional assumption of restoration of SU(2) symmetry at asymptotic energies
Selleri, Franco
Weak Relativity is an equivalent theory to Special Relativity according to Reichenbach's definition, where the parameter epsilon equals to 0. It formulates a Neo-Lorentzian approach by replacing the Lorentz transformations with a new set named "Inertial Transformations", thus explaining the Sagnac effect, the twin paradox and the trip from the future to the past in an easy and elegant way. The cosmic microwave background is suggested as a possible privileged reference system. Most importantly, being a theory based on experimental proofs, rather than mutual consensus, it offers a physical description of reality independent of the human observation.
Staggering towards a calculation of weak amplitudes
Energy Technology Data Exchange (ETDEWEB)
Sharpe, S.R.
An explanation is given of the methods required to calculate hadronic matrix elements of the weak Hamiltonians using lattice QCD with staggered fermions. New results are presented for the 1-loop perturbative mixing of the weak interaction operators. New numerical techniques designed for staggered fermions are described. A preliminary result for the kaon B parameter is presented. 24 refs., 3 figs.
Reconstructing weak values without weak measurements
International Nuclear Information System (INIS)
Johansen, Lars M.
I propose a scheme for reconstructing the weak value of an observable without the need for weak measurements. The post-selection in weak measurements is replaced by an initial projector measurement. The observable can be measured using any form of interaction, including projective measurements. The reconstruction is effected by measuring the change in the expectation value of the observable due to the projector measurement. The weak value may take nonclassical values if the projector measurement disturbs the expectation value of the observable
International Nuclear Information System (INIS)
Son, Mi Jung; Park, Jin Han; Lim, Ki Moon
We introduce a new class of functions called weakly clopen function which includes the class of almost clopen functions due to Ekici [Ekici E. Generalization of perfectly continuous, regular set-connected and clopen functions. Acta Math Hungar 2005;107:193-206] and is included in the class of weakly continuous functions due to Levine [Levine N. A decomposition of continuity in topological spaces. Am Math Mon 1961;68:44-6]. Some characterizations and several properties concerning weakly clopenness are obtained. Furthermore, relationships among weak clopenness, almost clopenness, clopenness and weak continuity are investigated
Vaidman, L.
Recent controversy regarding the meaning and usefulness of weak values is reviewed. It is argued that in spite of recent statistical arguments by Ferrie and Combes, experiments with anomalous weak values provide useful amplification techniques for precision measurements of small effects in many realistic situations. The statistical nature of weak values is questioned. Although measuring weak values requires an ensemble, it is argued that the weak value, similarly to an eigenvalue, is a property of a single pre- and post-selected quantum system. This article is part of the themed issue `Second quantum revolution: foundational questions'.
International Nuclear Information System (INIS)
Delorme, J.
The definition and general properties of weak second class currents are recalled and various detection possibilities briefly reviewed. It is shown that the existing data on nuclear beta decay can be consistently analysed in terms of a phenomenological model. Their implication on the fundamental structure of weak interactions is discussed [fr
Rehren, K. -H.
Weak C* Hopf algebras can act as global symmetries in low-dimensional quantum field theories, when braid group statistics prevents group symmetries. Possibilities to construct field algebras with weak C* Hopf symmetry from a given theory of local observables are discussed.
DEFF Research Database (Denmark)
Lukas, Manuel; Hillebrand, Eric
Relations between economic variables can often not be exploited for forecasting, suggesting that predictors are weak in the sense that estimation uncertainty is larger than bias from ignoring the relation. In this paper, we propose a novel bagging predictor designed for such weak predictor variab...
International Nuclear Information System (INIS)
Deshpande, N.G.
By electro-weak theory is meant the unified field theory that describes both weak and electro-magnetic interactions. The development of a unified electro-weak theory is certainly the most dramatic achievement in theoretical physics to occur in the second half of this century. It puts weak interactions on the same sound theoretical footing as quantum elecrodynamics. Many theorists have contributed to this development, which culminated in the works of Glashow, Weinberg and Salam, who were jointly awarded the 1979 Nobel Prize in physics. Some of the important ideas that contributed to this development are the theory of beta decay formulated by Fermi, Parity violation suggested by Lee and Yang, and incorporated into immensely successful V-A theory of weak interactions by Sudarshan and Marshak. At the same time ideas of gauge invariance were applied to weak interaction by Schwinger, Bludman and Glashow. Weinberg and Salam then went one step further and wrote a theory that is renormalizable, i.e., all higher order corrections are finite, no mean feat for a quantum field theory. The theory had to await the development of the quark model of hadrons for its completion. A description of the electro-weak theory is given
International Nuclear Information System (INIS)
Walecka, J.D.
Nuclei provide systems where the strong, electomagnetic, and weak interactions are all present. The current picture of the strong interactions is based on quarks and quantum chromodynamics (QCD). The symmetry structure of this theory is SU(3)/sub C/ x SU(2)/sub W/ x U(1)/sub W/. The electroweak interactions in nuclei can be used to probe this structure. Semileptonic weak interactions are considered. The processes under consideration include beta decay, neutrino scattering and weak neutral-current interactions. The starting point in the analysis is the effective Lagrangian of the Standard Model
Lee, T. D.
While the phenomenon of beta-decay was discovered near the end of the last century, the notion that the weak interaction forms a separate field of physical forces evolved rather gradually. This became clear only after the experimental discoveries of other weak reactions such as muon-decay, muon-capture, etc., and the theoretical observation that all these reactions can be described by approximately the same coupling constant, thus giving rise to the notion of a universal weak interaction. Only then did one slowly recognize that the weak interaction force forms an independent field, perhaps on the same footing as the gravitational force, the electromagnetic force, and the strong nuclear and sub-nuclear forces.
International Nuclear Information System (INIS)
The possibility of the production of weak bosons in the proton-antiproton colliding beam facilities which are currently being developed, is discussed. The production, decay and predicted properties of these particles are described. (W.D.L.).
International Nuclear Information System (INIS)
Turlay, R.
In this review of charged weak currents I shall concentrate on inclusive high energy neutrino physics. There are surely still things to learn from the low energy weak interaction but I will not discuss it here. Furthermore B. Tallini will discuss the hadronic final state of neutrino interactions. Since the Tokyo conference a few experimental results have appeared on charged current interaction, I will present them and will also comment on important topics which have been published during the last past year. (orig.)
International Nuclear Information System (INIS)
Daumenov, T.D.; Alizarovskaya, I.M.; Khizirova, M.A.
The method of the weakly oval electrical field getting generated by the axially-symmetrical field is shown. Such system may be designed with help of the cylindric form coaxial electrodes with the built-in quadrupole duplet. The singularity of the indicated weakly oval lense consists of that it provides the conducting both mechanical and electronic adjustment. Such lense can be useful for elimination of the near-axis astigmatism in the electron-optical system
Franklin, Joel N
Mathematically rigorous introduction covers vector and matrix norms, the condition-number of a matrix, positive and irreducible matrices, much more. Only elementary algebra and calculus required. Includes problem-solving exercises. 1968 edition.
Nonmesonic weak decay of the hypertriton
International Nuclear Information System (INIS)
Bennhold, C.; Ramos, A.; Aruliah, D.A.; Oelfke, U.
The nonmesonic weak decay of Λ 3 H is evaluated microscopically in the pion exchange model. The correlated three-body wave function of the hypertriton is approximated by a bound Λ-deuteron system obtained by averaging the YN interaction over the deuteron wave function. The relevant matrix elements are calculated in momentum space. The resulting decay rate is 4.9% of the free Λ decay rate
International Nuclear Information System (INIS)
Roberts, B.L.; Booth, E.C.; Gall, K.P.; McIntyre, E.K.; Miller, J.P.; Whitehouse, D.A.; Bassalleck, B.; Hall, J.R.; Larson, K.D.; Wolfe, D.M.; Fickinger, W.J.; Robinson, D.K.; Hallin, A.L.; Hasinoff, M.D.; Measday, D.F.; Noble, A.J.; Waltham, C.E.; Hessey, N.P.; Lowe, J.; Horvath, D.; Salomon, M.
New measurements of the Σ + and Λ weak radiative decays are discussed. The hyperons were produced at rest by the reaction K - p → Yπ where Y = Σ + or Λ. The monoenergetic pion was used to tag the hyperon production, and the branching ratios were determined from the relative amplitudes of Σ + → pγ to Σ + → pπ 0 and Λ → nγ to Λ → nπ 0 . The photons from weak radiative decays and from π 0 decays were detected with modular NaI arrays. (orig.)
Startpoints via weak contractions
Agyingi, Collins Amburo; Gaba, Yaé Ulrich
Startpoints (resp. endpoints) can be defined as "oriented fixed points". They arise naturally in the study of fixed for multi-valued maps defined on quasi-metric spaces. In this article, we give a new result in the startpoint theory for quasi-pseudometric spaces. The result we present is obtained via a generalized weakly contractive set-valued map.
Hadi, Inaam M. A.; Al-aeashi, Shukur N.
If R is a ring with identity and M is a unitary right R-module. Here we introduce the class of weakly coretractable module. Some basic properties are investigated and some relationships between these modules and other related one are introduced.
Inversion assuming weak scattering
DEFF Research Database (Denmark)
Xenaki, Angeliki; Gerstoft, Peter; Mosegaard, Klaus
due to the complex nature of the field. A method based on linear inversion is employed to infer information about the statistical properties of the scattering field from the obtained cross-spectral matrix. A synthetic example based on an active high-frequency sonar demonstrates that the proposed...
Introduction to weak interactions
International Nuclear Information System (INIS)
Leite Lopes, J.
An account is first given of the electromagnetic interactions of complex, scalar, vector and spinor fields. It is shown that the electromagnetic field may be considered as a gauge field. Yang-Mills fields and the field theory invariant with respect to the non-Abelian gauge transformation group are then described. The construction, owing to this invariance principle, of conserved isospin currents associated with gauge fields is also demonstrated. This is followed by a historical survey of the development of the weak interaction theory, established at first to describe beta disintegration processes by analogy with electrodynamics. The various stages are mentioned from the discovery of principles and rules and violation of principles, such as those of invariance with respect to spatial reflection and charge conjugation to the formulation of the effective current-current Lagrangian and research on the structure of weak currents [fr
Rakipi, Albert
Cataloged from PDF version of article. Although the weak 1 failing states have often been deseribed as the single most important problem for the international order s ince the en d of Cold W ar (F .Fukuyaına 2004:92) several dimensions of this phenomenon still remain unexplored. While this phenomenon has been present in the international politics even earlier, only the post Cold W ar period accentuated its relationship with security issues. Following the Cold W ar' s "peacef...
Energy Technology Data Exchange (ETDEWEB)
Suzuki, M.
Dynamical mechanism of composite W and Z is studied in a 1/N field theory model with four-fermion interactions in which global weak SU(2) symmetry is broken explicitly by electromagnetic interaction. Issues involved in such a model are discussed in detail. Deviation from gauge coupling due to compositeness and higher order loop corrections are examined to show that this class of models are consistent not only theoretically but also experimentally.
Nee, Sean
Survival analysis in biology and reliability theory in engineering concern the dynamical functioning of bio/electro/mechanical units. Here we incorporate effects of chaotic dynamics into the classical theory. Dynamical systems theory now distinguishes strong and weak chaos. Strong chaos generates Type II survivorship curves entirely as a result of the internal operation of the system, without any age-independent, external, random forces of mortality. Weak chaos exhibits (a) intermittency and (b) Type III survivorship, defined as a decreasing per capita mortality rate: engineering explicitly defines this pattern of decreasing hazard as 'infant mortality'. Weak chaos generates two phenomena from the normal functioning of the same system. First, infant mortality- sensu engineering-without any external explanatory factors, such as manufacturing defects, which is followed by increased average longevity of survivors. Second, sudden failure of units during their normal period of operation, before the onset of age-dependent mortality arising from senescence. The relevance of these phenomena encompasses, for example: no-fault-found failure of electronic devices; high rates of human early spontaneous miscarriage/abortion; runaway pacemakers; sudden cardiac death in young adults; bipolar disorder; and epilepsy.
Bayesian Markov Chain Monte Carlo inversion for weak anisotropy parameters and fracture weaknesses using azimuthal elastic impedance
Chen, Huaizhen; Pan, Xinpeng; Ji, Yuxin; Zhang, Guangzhi
A system of aligned vertical fractures and fine horizontal shale layers combine to form equivalent orthorhombic media. Weak anisotropy parameters and fracture weaknesses play an important role in the description of orthorhombic anisotropy (OA). We propose a novel approach of utilizing seismic reflection amplitudes to estimate weak anisotropy parameters and fracture weaknesses from observed seismic data, based on azimuthal elastic impedance (EI). We first propose perturbation in stiffness matrix in terms of weak anisotropy parameters and fracture weaknesses, and using the perturbation and scattering function, we derive PP-wave reflection coefficient and azimuthal EI for the case of an interface separating two OA media. Then we demonstrate an approach to first use a model constrained damped least-squares algorithm to estimate azimuthal EI from partially incidence-phase-angle-stack seismic reflection data at different azimuths, and then extract weak anisotropy parameters and fracture weaknesses from the estimated azimuthal EI using a Bayesian Markov Chain Monte Carlo inversion method. In addition, a new procedure to construct rock physics effective model is presented to estimate weak anisotropy parameters and fracture weaknesses from well log interpretation results (minerals and their volumes, porosity, saturation, fracture density, etc.). Tests on synthetic and real data indicate that unknown parameters including elastic properties (P- and S-wave impedances and density), weak anisotropy parameters and fracture weaknesses can be estimated stably in the case of seismic data containing a moderate noise, and our approach can make a reasonable estimation of anisotropy in a fractured shale reservoir.
Hypernuclear weak decay puzzle
International Nuclear Information System (INIS)
Barbero, C.; Horvat, D.; Narancic, Z.; Krmpotic, F.; Kuo, T.T.S.; Tadic, D.
A general shell model formalism for the nonmesonic weak decay of the hypernuclei has been developed. It involves a partial wave expansion of the emitted nucleon waves, preserves naturally the antisymmetrization between the escaping particles and the residual core, and contains as a particular case the weak Λ-core coupling formalism. The extreme particle-hole model and the quasiparticle Tamm-Dancoff approximation are explicitly worked out. It is shown that the nuclear structure manifests itself basically through the Pauli principle, and a very simple expression is derived for the neutron- and proton-induced decays rates Γ n and Γ p , which does not involve the spectroscopic factors. We use the standard strangeness-changing weak ΛN→NN transition potential which comprises the exchange of the complete pseudoscalar and vector meson octets (π,η,K,ρ,ω,K * ), taking into account some important parity-violating transition operators that are systematically omitted in the literature. The interplay between different mesons in the decay of Λ 12 C is carefully analyzed. With the commonly used parametrization in the one-meson-exchange model (OMEM), the calculated rate Γ NM =Γ n +Γ p is of the order of the free Λ decay rate Γ 0 (Γ NM th congruent with Γ 0 ) and is consistent with experiments. Yet the measurements of Γ n/p =Γ n /Γ p and of Γ p are not well accounted for by the theory (Γ n/p th p th > or approx. 0.60Γ 0 ). It is suggested that, unless additional degrees of freedom are incorporated, the OMEM parameters should be radically modified
Measurement of weak radioactivity
Theodorsson , P
This book is intended for scientists engaged in the measurement of weak alpha, beta, and gamma active samples; in health physics, environmental control, nuclear geophysics, tracer work, radiocarbon dating etc. It describes the underlying principles of radiation measurement and the detectors used. It also covers the sources of background, analyzes their effect on the detector and discusses economic ways to reduce the background. The most important types of low-level counting systems and the measurement of some of the more important radioisotopes are described here. In cases where more than one type can be used, the selection of the most suitable system is shown.
DEFF Research Database (Denmark)
Kohlenbach, Ulrich Wilhelm
We show that the so-called weak Markov's principle (WMP) which states that every pseudo-positive real number is positive is underivable in E-HA + AC. Since allows one to formalize (atl eastl arge parts of) Bishop's constructive mathematics, this makes it unlikely that WMP can be proved within...... the framework of Bishop-style mathematics (which has been open for about 20 years). The underivability even holds if the ine.ective schema of full comprehension (in all types) for negated formulas (in particular for -free formulas) is added, which allows one to derive the law of excluded middle...
International Nuclear Information System (INIS)
Sugarbaker, E.
I review available techniques for extraction of weak interaction rates in nuclei. The case for using hadron charge exchange reactions to estimate such rates is presented and contrasted with alternate methods. Limitations of the (p,n) reaction as a probe of Gamow-Teller strength are considered. Review of recent comparisons between beta-decay studies and (p,n) is made, leading to cautious optimism regarding the final usefulness of (p,n)- derived GT strengths to the field of astrophysics. copyright 1995 American Institute of Physics
Matrix Metalloproteinases in Myasthenia Gravis
Helgeland, G.; Petzold, A.F.S.; Luckman, S.P.; Gilhus, N.E.; Plant, G.T.; Romi, F.R.
Introduction: Myasthenia gravis (MG) is an autoimmune disease with weakness in striated musculature due to anti-acetylcholine receptor (AChR) antibodies or muscle specific kinase at the neuromuscular junction. A subgroup of patients has periocular symptoms only; ocular MG (OMG). Matrix
Weakly Supervised Dictionary Learning
You, Zeyu; Raich, Raviv; Fern, Xiaoli Z.; Kim, Jinsub
We present a probabilistic modeling and inference framework for discriminative analysis dictionary learning under a weak supervision setting. Dictionary learning approaches have been widely used for tasks such as low-level signal denoising and restoration as well as high-level classification tasks, which can be applied to audio and image analysis. Synthesis dictionary learning aims at jointly learning a dictionary and corresponding sparse coefficients to provide accurate data representation. This approach is useful for denoising and signal restoration, but may lead to sub-optimal classification performance. By contrast, analysis dictionary learning provides a transform that maps data to a sparse discriminative representation suitable for classification. We consider the problem of analysis dictionary learning for time-series data under a weak supervision setting in which signals are assigned with a global label instead of an instantaneous label signal. We propose a discriminative probabilistic model that incorporates both label information and sparsity constraints on the underlying latent instantaneous label signal using cardinality control. We present the expectation maximization (EM) procedure for maximum likelihood estimation (MLE) of the proposed model. To facilitate a computationally efficient E-step, we propose both a chain and a novel tree graph reformulation of the graphical model. The performance of the proposed model is demonstrated on both synthetic and real-world data.
Bodewig, E
Matrix Calculus, Second Revised and Enlarged Edition focuses on systematic calculation with the building blocks of a matrix and rows and columns, shunning the use of individual elements. The publication first offers information on vectors, matrices, further applications, measures of the magnitude of a matrix, and forms. The text then examines eigenvalues and exact solutions, including the characteristic equation, eigenrows, extremum properties of the eigenvalues, bounds for the eigenvalues, elementary divisors, and bounds for the determinant. The text ponders on approximate solutions, as well
Asymptotic Distribution of Eigenvalues of Weakly Dilute Wishart Matrices
Energy Technology Data Exchange (ETDEWEB)
Khorunzhy, A. [Institute for Low Temperature Physics (Ukraine)], E-mail: email@example.com; Rodgers, G. J. [Brunel University, Uxbridge, Department of Mathematics and Statistics (United Kingdom)], E-mail: email@example.com
We study the eigenvalue distribution of large random matrices that are randomly diluted. We consider two random matrix ensembles that in the pure (nondilute) case have a limiting eigenvalue distribution with a singular component at the origin. These include the Wishart random matrix ensemble and Gaussian random matrices with correlated entries. Our results show that the singularity in the eigenvalue distribution is rather unstable under dilution and that even weak dilution destroys it.
International Nuclear Information System (INIS)
Craps, Ben; Evnin, Oleg; Nguyen, Kévin
Matrix quantum mechanics offers an attractive environment for discussing gravitational holography, in which both sides of the holographic duality are well-defined. Similarly to higher-dimensional implementations of holography, collapsing shell solutions in the gravitational bulk correspond in this setting to thermalization processes in the dual quantum mechanical theory. We construct an explicit, fully nonlinear supergravity solution describing a generic collapsing dilaton shell, specify the holographic renormalization prescriptions necessary for computing the relevant boundary observables, and apply them to evaluating thermalizing two-point correlation functions in the dual matrix theory.
Craps, Ben; Evnin, Oleg; Nguyen, Kévin
Matrix quantum mechanics offers an attractive environment for discussing gravitational holography, in which both sides of the holographic duality are well-defined. Similarly to higher-dimensional implementations of holography, collapsing shell solutions in the gravitational bulk correspond in this setting to thermalization processes in the dual quantum mechanical theory. We construct an explicit, fully nonlinear supergravity solution describing a generic collapsing dilaton shell, specify the holographic renormalization prescriptions necessary for computing the relevant boundary observables, and apply them to evaluating thermalizing two-point correlation functions in the dual matrix theory.
Energy Technology Data Exchange (ETDEWEB)
Craps, Ben [Theoretische Natuurkunde, Vrije Universiteit Brussel (VUB), and International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium); Evnin, Oleg [Department of Physics, Faculty of Science, Chulalongkorn University, Thanon Phayathai, Pathumwan, Bangkok 10330 (Thailand); Theoretische Natuurkunde, Vrije Universiteit Brussel (VUB), and International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium); Nguyen, Kévin [Theoretische Natuurkunde, Vrije Universiteit Brussel (VUB), and International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium)
Matrix quantum mechanics offers an attractive environment for discussing gravitational holography, in which both sides of the holographic duality are well-defined. Similarly to higher-dimensional implementations of holography, collapsing shell solutions in the gravitational bulk correspond in this setting to thermalization processes in the dual quantum mechanical theory. We construct an explicit, fully nonlinear supergravity solution describing a generic collapsing dilaton shell, specify the holographic renormalization prescriptions necessary for computing the relevant boundary observables, and apply them to evaluating thermalizing two-point correlation functions in the dual matrix theory.
Weak interactions of quarks and leptons: experimental status
International Nuclear Information System (INIS)
Wojcicki, S.
The present experimental status of weak interactions is discussed with emphasis on the problems and questions and on the possible lines of future investigations. Major topics include; (1) the quark mixing matrix, (2) CP violation, (3) rare decays, (4) the lepton sector, and (5) right handed currents. 118 references
Partial Widths of Nonmesonic Weak Decays of Lambda-Hypernuclei
Kuzmin, V A
It is shown that the phenomenological matrix elements completely describing \\Lambda N \\to NN weak interaction in the 1p-shell nuclei can be obtained from the partial widths of nonmesonic decays of ^{10}_{\\Lambda}Be and ^{10}_{\\Lambda}B hypernuclei. It is shown that the uncertainties related to the description of nuclear structure are not essential for this task.
Zilberberg, Oded; Romito, Alessandro; Gefen, Yuval
Weak value (WV) is a quantum mechanical measurement protocol, proposed by Aharonov, Albert, and Vaidman. It consists of a weak measurement, which is weighed in, conditional on the outcome of a later, strong measurement. Here we define another two-step measurement protocol, null weak value (NVW), and point out its advantages as compared to WV. We present two alternative derivations of NWVs and compare them to the corresponding derivations of WVs.
Weak openness and almost openness
Directory of Open Access Journals (Sweden)
David A. Rose
Full Text Available Weak openness and almost openness for arbitrary functions between topological spaces are defined as duals to the weak continuity of Levine and the almost continuity of Husain respectively. Independence of these two openness conditions is noted and comparison is made between these and the almost openness of Singal and Singal. Some results dual to those known for weak continuity and almost continuity are obtained. Nearly almost openness is defined and used to obtain an improved link from weak continuity to almost continuity.
Weak measurements and quantum weak values for NOON states
Rosales-Zárate, L.; Opanchuk, B.; Reid, M. D.
Quantum weak values arise when the mean outcome of a weak measurement made on certain preselected and postselected quantum systems goes beyond the eigenvalue range for a quantum observable. Here, we propose how to determine quantum weak values for superpositions of states with a macroscopically or mesoscopically distinct mode number, that might be realized as two-mode Bose-Einstein condensate or photonic NOON states. Specifically, we give a model for a weak measurement of the Schwinger spin of a two-mode NOON state, for arbitrary N . The weak measurement arises from a nondestructive measurement of the two-mode occupation number difference, which for atomic NOON states might be realized via phase contrast imaging and the ac Stark effect using an optical meter prepared in a coherent state. The meter-system coupling results in an entangled cat-state. By subsequently evolving the system under the action of a nonlinear Josephson Hamiltonian, we show how postselection leads to quantum weak values, for arbitrary N . Since the weak measurement can be shown to be minimally invasive, the weak values provide a useful strategy for a Leggett-Garg test of N -scopic realism.
Zhan, Xingzhi
The main purpose of this monograph is to report on recent developments in the field of matrix inequalities, with emphasis on useful techniques and ingenious ideas. Among other results this book contains the affirmative solutions of eight conjectures. Many theorems unify or sharpen previous inequalities. The author's aim is to streamline the ideas in the literature. The book can be read by research workers, graduate students and advanced undergraduates.
Weak decays of stable particles
International Nuclear Information System (INIS)
Brown, R.M.
In this article we review recent advances in the field of weak decays and consider their implications for quantum chromodynamics (the theory of strong interactions) and electroweak theory (the combined theory of electromagnetic and weak interactions), which together form the ''Standard Model'' of elementary particles. (author)
Electromagnetic current in weak interactions
International Nuclear Information System (INIS)
Ma, E.
In gauge models which unify weak and electromagnetic interactions, the weak neutral-current interaction also involves the electromagnetic current. The exact nature of such a component can be explored using e + e - experimental data. In recent years, the existence of a new component of the weak interaction has become firmly established, i.e., the neutral-current interaction. As such, it competes with the electromagnetic interaction whenever the particles involved are also charged, but at a very much lower rate because its effective strength is so small. Hence neutrino processes are best for the detection of the neutral-current interaction. However, in any gauge model which unifies weak and electromagnetic interactions, the weak neutral-current interaction also involves the electromagnetic current
Weak values in collision theory
de Castro, Leonardo Andreta; Brasil, Carlos Alexandre; Napolitano, Reginaldo de Jesus
Weak measurements have an increasing number of applications in contemporary quantum mechanics. They were originally described as a weak interaction that slightly entangled the translational degrees of freedom of a particle to its spin, yielding surprising results after post-selection. That description often ignores the kinetic energy of the particle and its movement in three dimensions. Here, we include these elements and re-obtain the weak values within the context of collision theory by two different approaches, and prove that the results are compatible with each other and with the results from the traditional approach. To provide a more complete description, we generalize weak values into weak tensors and use them to provide a more realistic description of the Stern-Gerlach apparatus.
Hartman effect and weak measurements that are not really weak
International Nuclear Information System (INIS)
Sokolovski, D.; Akhmatskaya, E.
We show that in wave packet tunneling, localization of the transmitted particle amounts to a quantum measurement of the delay it experiences in the barrier. With no external degree of freedom involved, the envelope of the wave packet plays the role of the initial pointer state. Under tunneling conditions such ''self-measurement'' is necessarily weak, and the Hartman effect just reflects the general tendency of weak values to diverge, as postselection in the final state becomes improbable. We also demonstrate that it is a good precision, or a 'not really weak' quantum measurement: no matter how wide the barrier d, it is possible to transmit a wave packet with a width σ small compared to the observed advancement. As is the case with all weak measurements, the probability of transmission rapidly decreases with the ratio σ/d.
Bhatia, Rajendra
A good part of matrix theory is functional analytic in spirit. This statement can be turned around. There are many problems in operator theory, where most of the complexities and subtleties are present in the finite-dimensional case. My purpose in writing this book is to present a systematic treatment of methods that are useful in the study of such problems. This book is intended for use as a text for upper division and gradu ate courses. Courses based on parts of the material have been given by me at the Indian Statistical Institute and at the University of Toronto (in collaboration with Chandler Davis). The book should also be useful as a reference for research workers in linear algebra, operator theory, mathe matical physics and numerical analysis. A possible subtitle of this book could be Matrix Inequalities. A reader who works through the book should expect to become proficient in the art of deriving such inequalities. Other authors have compared this art to that of cutting diamonds. One first has to...
Quenching of weak interactions in nucleon matter
International Nuclear Information System (INIS)
Cowell, S.; Pandharipande, V.R.
We have calculated the one-body Fermi and Gamow-Teller charge-current and vector and axial-vector neutral-current nuclear matrix elements in nucleon matter at densities of 0.08, 0.16, and 0.24 fm -3 and proton fractions ranging from 0.2 to 0.5. The correlated states for nucleon matter are obtained by operating on Fermi-gas states by a symmetrized product of pair correlation operators determined from variational calculations with the Argonne-v18 and Urbana-IX two- and three-nucleon interactions. The squares of the charge- current matrix elements are found to be quenched by 20-25 % by the short-range correlations in nucleon matter. Most of the quenching is due to spin-isospin correlations induced by the pion exchange interactions which change the isospins and spins of the nucleons. A large part of it can be related to the probability for a spin-up proton quasiparticle to be a bare spin-up/down proton/neutron. Within the interval considered, the charge-current matrix elements do not have significant dependence on the matter density, proton fraction, and magnitudes of nucleon momenta; however, they do depend on momentum transfer. The neutral-current matrix elements have a significant dependence on the proton fraction. We also calculate the matrix elements of the nuclear Hamiltonian in the same correlated basis. These provide relatively mild effective interactions that give the variational energies in the Hartree-Fock approximation. The calculated two-nucleon effective interaction describes the spin-isospin susceptibilities of nuclear and neutron matter fairly accurately. However terms greater than or equal to three-body terms are necessary to reproduce the compressibility. Realistic calculations of weak interaction rates in nucleon matter can presumably be carried out using the effective operators and interactions studied here. All presented results use the simple two-body cluster approximation to calculate the correlated basis matrix elements. This allows for a clear
Sex hormones and skeletal muscle weakness
DEFF Research Database (Denmark)
Sipilä, Sarianna; Narici, Marco; Kjaer, Michael
Human ageing is accompanied with deterioration in endocrine functions the most notable and well characterized of which being the decrease in the production of sex hormones. Current research literature suggests that low sex hormone concentration may be among the key mechanism for sarcopenia...... and muscle weakness. Within the European large scale MYOAGE project, the role of sex hormones, estrogens and testosterone, in causing the aging-related loss of muscle mass and function was further investigated. Hormone replacement therapy (HRT) in women is shown to diminish age-associated muscle loss, loss...... properties. HRT influences gene expression in e.g. cytoskeletal and cell-matrix proteins, has a stimulating effect upon IGF-I, and a role in IL-6 and adipokine regulation. Despite low circulating steroid-hormone level, postmenopausal women have a high local concentration of steroidogenic enzymes in skeletal...
Weak Measurement and Quantum Correlation
Indian Academy of Sciences (India)
Arun Kumar Pati
Entanglement: Two quantum systems can be in a strongly correlated state even if .... These are resources which can be used to design quantum computer, quantum ...... Weak measurements have found numerous applications starting from the ...
Weakly infinite-dimensional spaces
International Nuclear Information System (INIS)
Fedorchuk, Vitalii V
In this survey article two new classes of spaces are considered: m-C-spaces and w-m-C-spaces, m=2,3,...,∞. They are intermediate between the class of weakly infinite-dimensional spaces in the Alexandroff sense and the class of C-spaces. The classes of 2-C-spaces and w-2-C-spaces coincide with the class of weakly infinite-dimensional spaces, while the compact ∞-C-spaces are exactly the C-compact spaces of Haver. The main results of the theory of weakly infinite-dimensional spaces, including classification via transfinite Lebesgue dimensions and Luzin-Sierpinsky indices, extend to these new classes of spaces. Weak m-C-spaces are characterised by means of essential maps to Henderson's m-compacta. The existence of hereditarily m-strongly infinite-dimensional spaces is proved.
Weak interactions and presupernova evolution
International Nuclear Information System (INIS)
Aufderheide, M.B.; State Univ. of New York
The role of weak interactions, particularly electron capture and β - decay, in presupernova evolution is discussed. The present uncertainty in these rates is examined and the possibility of improving the situation is addressed. 12 refs., 4 figs
Weak Deeply Virtual Compton Scattering
International Nuclear Information System (INIS)
Ales Psaker; Wolodymyr Melnitchouk; Anatoly Radyushkin
We extend the analysis of the deeply virtual Compton scattering process to the weak interaction sector in the generalized Bjorken limit. The virtual Compton scattering amplitudes for the weak neutral and charged currents are calculated at the leading twist within the framework of the nonlocal light-cone expansion via coordinate space QCD string operators. Using a simple model, we estimate cross sections for neutrino scattering off the nucleon, relevant for future high intensity neutrino beam facilities
Weakly compact operators and interpolation
Maligranda, Lech
The class of weakly compact operators is, as well as the class of compact operators, a fundamental operator ideal. They were investigated strongly in the last twenty years. In this survey, we have collected and ordered some of this (partly very new) knowledge. We have also included some comments, remarks and examples. The class of weakly compact operators is, as well as the class of compact operators, a fundamental operator ideal. They were investigated strongly in the last twenty years. I...
Belitsky, A. V.
The Operator Product Expansion for null polygonal Wilson loop in planar maximally supersymmetric Yang-Mills theory runs systematically in terms of multi-particle pentagon transitions which encode the physics of excitations propagating on the color flux tube ending on the sides of the four-dimensional contour. Their dynamics was unraveled in the past several years and culminated in a complete description of pentagons as an exact function of the 't Hooft coupling. In this paper we provide a solution for the last building block in this program, the SU(4) matrix structure arising from internal symmetry indices of scalars and fermions. This is achieved by a recursive solution of the Mirror and Watson equations obeyed by the so-called singlet pentagons and fixing the form of the twisted component in their tensor decomposition. The non-singlet, or charged, pentagons are deduced from these by a limiting procedure.
Directory of Open Access Journals (Sweden)
A.V. Belitsky
Full Text Available The Operator Product Expansion for null polygonal Wilson loop in planar maximally supersymmetric Yang–Mills theory runs systematically in terms of multi-particle pentagon transitions which encode the physics of excitations propagating on the color flux tube ending on the sides of the four-dimensional contour. Their dynamics was unraveled in the past several years and culminated in a complete description of pentagons as an exact function of the 't Hooft coupling. In this paper we provide a solution for the last building block in this program, the SU(4 matrix structure arising from internal symmetry indices of scalars and fermions. This is achieved by a recursive solution of the Mirror and Watson equations obeyed by the so-called singlet pentagons and fixing the form of the twisted component in their tensor decomposition. The non-singlet, or charged, pentagons are deduced from these by a limiting procedure.
Acute muscular weakness in children
Directory of Open Access Journals (Sweden)
Ricardo Pablo Javier Erazo Torricelli
Full Text Available ABSTRACT Acute muscle weakness in children is a pediatric emergency. During the diagnostic approach, it is crucial to obtain a detailed case history, including: onset of weakness, history of associated febrile states, ingestion of toxic substances/toxins, immunizations, and family history. Neurological examination must be meticulous as well. In this review, we describe the most common diseases related to acute muscle weakness, grouped into the site of origin (from the upper motor neuron to the motor unit. Early detection of hyperCKemia may lead to a myositis diagnosis, and hypokalemia points to the diagnosis of periodic paralysis. Ophthalmoparesis, ptosis and bulbar signs are suggestive of myasthenia gravis or botulism. Distal weakness and hyporeflexia are clinical features of Guillain-Barré syndrome, the most frequent cause of acute muscle weakness. If all studies are normal, a psychogenic cause should be considered. Finding the etiology of acute muscle weakness is essential to execute treatment in a timely manner, improving the prognosis of affected children.
Correlation matrix for quartet codon usage
Frappat, L; Sorba, Paul
It has been argued that the sum of usage probabilities for codons, belonging to quartets, that have as third nucleotide C or A, is independent of the biological species for vertebrates. The comparison between the theoretical correlation matrix derived from these sum rules and the experimentally computed matrix for 26 species shows a satisfactory agreement. The Shannon entropy, weakly depending on the biological species, gives further support. Suppression of codons containing the dinucleotides CG or AU is put in evidence.
Lattice results for heavy light matrix elements
International Nuclear Information System (INIS)
Soni, A.
Lattice results for heavy light matrix elements are reviewed and some of their implications are very briefly discussed. Despite the fact that in most cases the lattice results for weak matrix elements at the moment have only a modest accuracy of about 20--30% they already have important phenomenological repercussions; e.g. for V td /V ts , x s /x d and B → K*γ
Looking into weak processes from the light cone
International Nuclear Information System (INIS)
Hwang, W.Y.P.; Wai, C.F.; Henley, E.M.; Sczcepaniak, A.
In this paper, the authors explain why the light-cone language is useful in studying weak processes. As a specific example, the authors consider the bottom-meson decay B 0 d → π + π - using the spectator diagram. Using the factorization theorem, the authors relate in a quantitative manner the decay rate to the Cabibbo-Kobayashi-Maskawa matrix element V ub , paving the way for determining V ub through an experimental measurement of the decay rate Γ (B 0 d → π + π - . It is obvious that the present approach is applicable to many other weak processes where the instant dynamics may encounter practical difficulties
... by a slipped disk in the spine) Stroke MUSCLE DISEASES Becker muscular dystrophy Dermatomyositis Muscular dystrophy (Duchenne) Myotonic dystrophy POISONING Botulism Poisoning ( insecticides , nerve gas) ...
Cosmology with weak lensing surveys
International Nuclear Information System (INIS)
Munshi, Dipak; Valageas, Patrick; Waerbeke, Ludovic van; Heavens, Alan
Weak gravitational lensing is responsible for the shearing and magnification of the images of high-redshift sources due to the presence of intervening matter. The distortions are due to fluctuations in the gravitational potential, and are directly related to the distribution of matter and to the geometry and dynamics of the Universe. As a consequence, weak gravitational lensing offers unique possibilities for probing the Dark Matter and Dark Energy in the Universe. In this review, we summarise the theoretical and observational state of the subject, focussing on the statistical aspects of weak lensing, and consider the prospects for weak lensing surveys in the future. Weak gravitational lensing surveys are complementary to both galaxy surveys and cosmic microwave background (CMB) observations as they probe the unbiased non-linear matter power spectrum at modest redshifts. Most of the cosmological parameters are accurately estimated from CMB and large-scale galaxy surveys, so the focus of attention is shifting to understanding the nature of Dark Matter and Dark Energy. On the theoretical side, recent advances in the use of 3D information of the sources from photometric redshifts promise greater statistical power, and these are further enhanced by the use of statistics beyond two-point quantities such as the power spectrum. The use of 3D information also alleviates difficulties arising from physical effects such as the intrinsic alignment of galaxies, which can mimic weak lensing to some extent. On the observational side, in the next few years weak lensing surveys such as CFHTLS, VST-KIDS and Pan-STARRS, and the planned Dark Energy Survey, will provide the first weak lensing surveys covering very large sky areas and depth. In the long run even more ambitious programmes such as DUNE, the Supernova Anisotropy Probe (SNAP) and Large-aperture Synoptic Survey Telescope (LSST) are planned. Weak lensing of diffuse components such as the CMB and 21 cm emission can also
Cosmology with weak lensing surveys
Energy Technology Data Exchange (ETDEWEB)
Munshi, Dipak [Institute of Astronomy, Madingley Road, Cambridge, CB3 OHA (United Kingdom); Astrophysics Group, Cavendish Laboratory, Madingley Road, Cambridge CB3 OHE (United Kingdom)], E-mail: firstname.lastname@example.com; Valageas, Patrick [Service de Physique Theorique, CEA Saclay, 91191 Gif-sur-Yvette (France); Waerbeke, Ludovic van [University of British Columbia, Department of Physics and Astronomy, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); Heavens, Alan [SUPA - Scottish Universities Physics Alliance, Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom)
Weak gravitational lensing is responsible for the shearing and magnification of the images of high-redshift sources due to the presence of intervening matter. The distortions are due to fluctuations in the gravitational potential, and are directly related to the distribution of matter and to the geometry and dynamics of the Universe. As a consequence, weak gravitational lensing offers unique possibilities for probing the Dark Matter and Dark Energy in the Universe. In this review, we summarise the theoretical and observational state of the subject, focussing on the statistical aspects of weak lensing, and consider the prospects for weak lensing surveys in the future. Weak gravitational lensing surveys are complementary to both galaxy surveys and cosmic microwave background (CMB) observations as they probe the unbiased non-linear matter power spectrum at modest redshifts. Most of the cosmological parameters are accurately estimated from CMB and large-scale galaxy surveys, so the focus of attention is shifting to understanding the nature of Dark Matter and Dark Energy. On the theoretical side, recent advances in the use of 3D information of the sources from photometric redshifts promise greater statistical power, and these are further enhanced by the use of statistics beyond two-point quantities such as the power spectrum. The use of 3D information also alleviates difficulties arising from physical effects such as the intrinsic alignment of galaxies, which can mimic weak lensing to some extent. On the observational side, in the next few years weak lensing surveys such as CFHTLS, VST-KIDS and Pan-STARRS, and the planned Dark Energy Survey, will provide the first weak lensing surveys covering very large sky areas and depth. In the long run even more ambitious programmes such as DUNE, the Supernova Anisotropy Probe (SNAP) and Large-aperture Synoptic Survey Telescope (LSST) are planned. Weak lensing of diffuse components such as the CMB and 21 cm emission can also
Peripheral facial weakness (Bell's palsy).
Basić-Kes, Vanja; Dobrota, Vesna Dermanović; Cesarik, Marijan; Matovina, Lucija Zadro; Madzar, Zrinko; Zavoreo, Iris; Demarin, Vida
Peripheral facial weakness is a facial nerve damage that results in muscle weakness on one side of the face. It may be idiopathic (Bell's palsy) or may have a detectable cause. Almost 80% of peripheral facial weakness cases are primary and the rest of them are secondary. The most frequent causes of secondary peripheral facial weakness are systemic viral infections, trauma, surgery, diabetes, local infections, tumor, immune disorders, drugs, degenerative diseases of the central nervous system, etc. The diagnosis relies upon the presence of typical signs and symptoms, blood chemistry tests, cerebrospinal fluid investigations, nerve conduction studies and neuroimaging methods (cerebral MRI, x-ray of the skull and mastoid). Treatment of secondary peripheral facial weakness is based on therapy for the underlying disorder, unlike the treatment of Bell's palsy that is controversial due to the lack of large, randomized, controlled, prospective studies. There are some indications that steroids or antiviral agents are beneficial but there are also studies that show no beneficial effect. Additional treatments include eye protection, physiotherapy, acupuncture, botulinum toxin, or surgery. Bell's palsy has a benign prognosis with complete recovery in about 80% of patients, 15% experience some mode of permanent nerve damage and severe consequences remain in 5% of patients.
Quantum discord with weak measurements
International Nuclear Information System (INIS)
Singh, Uttam; Pati, Arun Kumar
Weak measurements cause small change to quantum states, thereby opening up the possibility of new ways of manipulating and controlling quantum systems. We ask, can weak measurements reveal more quantum correlation in a composite quantum state? We prove that the weak measurement induced quantum discord, called as the "super quantum discord", is always larger than the quantum discord captured by the strong measurement. Moreover, we prove the monotonicity of the super quantum discord as a function of the measurement strength and in the limit of strong projective measurement the super quantum discord becomes the normal quantum discord. We find that unlike the normal discord, for pure entangled states, the super quantum discord can exceed the quantum entanglement. Our results provide new insights on the nature of quantum correlation and suggest that the notion of quantum correlation is not only observer dependent but also depends on how weakly one perturbs the composite system. We illustrate the key results for pure as well as mixed entangled states. -- Highlights: •Introduced the role of weak measurements in quantifying quantum correlation. •We have introduced the notion of the super quantum discord (SQD). •For pure entangled state, we show that the SQD exceeds the entanglement entropy. •This shows that quantum correlation depends not only on observer but also on measurement strength
Modern Nondestructive Test Methods for Army Ceramic Matrix Composites
National Research Council Canada - National Science Library
Strand, Douglas J
.... Ceramic matrix composites (CMC) are potentially good high-temperature structural materials because of their low density, high elastic moduli, high strength, and for those with weak interfaces, surprisingly good damage tolerance...
ISOLTRAP Mass Measurements for Weak-Interaction Studies
International Nuclear Information System (INIS)
Kellerbauer, A.; Delahaye, P.; Herlert, A.; Audi, G.; Guenaut, C.; Lunney, D.; Beck, D.; Herfurth, F.; Kluge, H.-J.; Mukherjee, M.; Rodriguez, D.; Weber, C.; Yazidjian, C.; Blaum, K.; Bollen, G.; Schwarz, S.; George, S.; Schweikhard, L.
The conserved-vector-current (CVC) hypothesis of the weak interaction and the unitarity of the Cabibbo-Kobayashi-Maskawa (CKM) matrix are two fundamental postulates of the Standard Model. While existing data on CVC supports vector current conservation, the unitarity test of the CKM matrix currently fails by more than two standard deviations. High-precision mass measurements performed with the ISOLTRAP experiment at ISOLDE/CERN provide crucial input for these fundamental studies by greatly improving our knowledge of the decay energy of super-allowed β decays. Recent results of mass measurements on the β emitters 18Ne, 22Mg, 34Ar, and 74Rb as pertaining to weak-interaction studies are presented
"Weak quantum chaos" and its resistor network modeling.
Stotland, Alexander; Pecora, Louis M; Cohen, Doron
Weakly chaotic or weakly interacting systems have a wide regime where the common random matrix theory modeling does not apply. As an example we consider cold atoms in a nearly integrable optical billiard with a displaceable wall (piston). The motion is completely chaotic but with a small Lyapunov exponent. The Hamiltonian matrix does not look like one taken from a Gaussian ensemble, but rather it is very sparse and textured. This can be characterized by parameters s and g which reflect the percentage of large elements and their connectivity, respectively. For g we use a resistor network calculation that has a direct relation to the semilinear response characteristics of the system, hence leading to a prediction regarding the energy absorption rate of cold atoms in optical billiards with vibrating walls.
Weak-interacting holographic QCD
International Nuclear Information System (INIS)
Gazit, D.; Yee, H.-U.
We propose a simple prescription for including low-energy weak-interactions into the frame- work of holographic QCD, based on the standard AdS/CFT dictionary of double-trace deformations. As our proposal enables us to calculate various electro-weak observables involving strongly coupled QCD, it opens a new perspective on phenomenological applications of holographic QCD. We illustrate efficiency and usefulness of our method by performing a few exemplar calculations; neutron beta decay, charged pion weak decay, and meson-nucleon parity non-conserving (PNC) couplings. The idea is general enough to be implemented in both Sakai-Sugimoto as well as Hard/Soft Wall models. (author)
Plane waves with weak singularities
International Nuclear Information System (INIS)
David, Justin R.
We study a class of time dependent solutions of the vacuum Einstein equations which are plane waves with weak null singularities. This singularity is weak in the sense that though the tidal forces diverge at the singularity, the rate of divergence is such that the distortion suffered by a freely falling observer remains finite. Among such weak singular plane waves there is a sub-class which does not exhibit large back reaction in the presence of test scalar probes. String propagation in these backgrounds is smooth and there is a natural way to continue the metric beyond the singularity. This continued metric admits string propagation without the string becoming infinitely excited. We construct a one parameter family of smooth metrics which are at a finite distance in the space of metrics from the extended metric and a well defined operator in the string sigma model which resolves the singularity. (author)
Weak Measurement and Quantum Smoothing of a Superconducting Qubit
Tan, Dian
In quantum mechanics, the measurement outcome of an observable in a quantum system is intrinsically random, yielding a probability distribution. The state of the quantum system can be described by a density matrix rho(t), which depends on the information accumulated until time t, and represents our knowledge about the system. The density matrix rho(t) gives probabilities for the outcomes of measurements at time t. Further probing of the quantum system allows us to refine our prediction in hindsight. In this thesis, we experimentally examine a quantum smoothing theory in a superconducting qubit by introducing an auxiliary matrix E(t) which is conditioned on information obtained from time t to a final time T. With the complete information before and after time t, the pair of matrices [rho(t), E(t)] can be used to make smoothed predictions for the measurement outcome at time t. We apply the quantum smoothing theory in the case of continuous weak measurement unveiling the retrodicted quantum trajectories and weak values. In the case of strong projective measurement, while the density matrix rho(t) with only diagonal elements in a given basis |n〉 may be treated as a classical mixture, we demonstrate a failure of this classical mixture description in determining the smoothed probabilities for the measurement outcome at time t with both diagonal rho(t) and diagonal E(t). We study the correlations between quantum states and weak measurement signals and examine aspects of the time symmetry of continuous quantum measurement. We also extend our study of quantum smoothing theory to the case of resonance fluorescence of a superconducting qubit with homodyne measurement and observe some interesting effects such as the modification of the excited state probabilities, weak values, and evolution of the predicted and retrodicted trajectories.
Description of intruded states in a weak-coupling basis
International Nuclear Information System (INIS)
Arenas Peris, G.E.
The systematics of intruder states is described in terms of a particle-hole weak-coupling basis, the first-order correction being then reduced to the monopole component of the interaction. The necessary matrix elements can be obtained from experimental data by using a model-consistent method. Calculations are performed for intruder states in the lead region as well as for the Zr isotopes. The agreement with the experimental data is striking in both cases. (Author) [es
Cosmology and the weak interaction
Energy Technology Data Exchange (ETDEWEB)
Schramm, D.N. (Fermi National Accelerator Lab., Batavia, IL (USA)):(Chicago Univ., IL (USA))
The weak interaction plays a critical role in modern Big Bang cosmology. This review will emphasize two of its most publicized cosmological connections: Big Bang nucleosynthesis and Dark Matter. The first of these is connected to the cosmological prediction of Neutrino Flavours, N{sub {nu}} {approximately} 3 which is now being confirmed at SLC and LEP. The second is interrelated to the whole problem of galaxy and structure formation in the universe. This review will demonstrate the role of the weak interaction both for dark matter candidates and for the problem of generating seeds to form structure. 87 refs., 3 figs., 5 tabs.
Cosmology and the weak interaction
International Nuclear Information System (INIS)
Schramm, D.N.
The weak interaction plays a critical role in modern Big Bang cosmology. This review will emphasize two of its most publicized cosmological connections: Big Bang nucleosynthesis and Dark Matter. The first of these is connected to the cosmological prediction of Neutrino Flavours, N ν ∼ 3 which is now being confirmed at SLC and LEP. The second is interrelated to the whole problem of galaxy and structure formation in the universe. This review will demonstrate the role of the weak interaction both for dark matter candidates and for the problem of generating seeds to form structure. 87 refs., 3 figs., 5 tabs
Nonlinear waves and weak turbulence
Zakharov, V E
This book is a collection of papers on dynamical and statistical theory of nonlinear wave propagation in dispersive conservative media. Emphasis is on waves on the surface of an ideal fluid and on Rossby waves in the atmosphere. Although the book deals mainly with weakly nonlinear waves, it is more than simply a description of standard perturbation techniques. The goal is to show that the theory of weakly interacting waves is naturally related to such areas of mathematics as Diophantine equations, differential geometry of waves, Poincaré normal forms, and the inverse scattering method.
Weak disorder in Fibonacci sequences
Energy Technology Data Exchange (ETDEWEB)
Ben-Naim, E [Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Krapivsky, P L [Department of Physics and Center for Molecular Cybernetics, Boston University, Boston, MA 02215 (United States)
We study how weak disorder affects the growth of the Fibonacci series. We introduce a family of stochastic sequences that grow by the normal Fibonacci recursion with probability 1 - {epsilon}, but follow a different recursion rule with a small probability {epsilon}. We focus on the weak disorder limit and obtain the Lyapunov exponent that characterizes the typical growth of the sequence elements, using perturbation theory. The limiting distribution for the ratio of consecutive sequence elements is obtained as well. A number of variations to the basic Fibonacci recursion including shift, doubling and copying are considered. (letter to the editor)
Weak interactions at high energies
International Nuclear Information System (INIS)
Ellis, J.
Review lectures are presented on the phenomenological implications of the modern spontaneously broken gauge theories of the weak and electromagnetic interactions, and some observations are made about which high energy experiments probe what aspects of gauge theories. Basic quantum chromodynamics phenomenology is covered including momentum dependent effective quark distributions, the transverse momentum cutoff, search for gluons as sources of hadron jets, the status and prospects for the spectroscopy of fundamental fermions and how fermions may be used to probe aspects of the weak and electromagnetic gauge theory, studies of intermediate vector bosons, and miscellaneous possibilities suggested by gauge theories from the Higgs bosons to speculations about proton decay. 187 references
Weak localization of seismic waves
International Nuclear Information System (INIS)
Larose, E.; Margerin, L.; Tiggelen, B.A. van; Campillo, M.
We report the observation of weak localization of seismic waves in a natural environment. It emerges as a doubling of the seismic energy around the source within a spot of the width of a wavelength, which is several tens of meters in our case. The characteristic time for its onset is the scattering mean-free time that quantifies the internal heterogeneity
Thomys, Janus; Zhang, Xiaohong
We describe weak-BCC-algebras (also called BZ-algebras) in which the condition (x∗y)∗z = (x∗z)∗y is satisfied only in the case when elements x, y belong to the same branch. We also characterize ideals, nilradicals, and nilpotent elements of such algebras. PMID:24311983
Voltage Weak DC Distribution Grids
Hailu, T.G.; Mackay, L.J.; Ramirez Elizondo, L.M.; Ferreira, J.A.
This paper describes the behavior of voltage weak DC distribution systems. These systems have relatively small system capacitance. The size of system capacitance, which stores energy, has a considerable effect on the value of fault currents, control complexity, and system reliability. A number of
The structure of weak interaction
International Nuclear Information System (INIS)
Zee, A.
The effect of introducing righthanded currents on the structure of weak interaction is discussed. The ΔI=1/2 rule is in the spotlight. The discussion provides an interesting example in which the so-called Iizuka-Okubo-Zweing rule is not only evaded, but completely negated
Coverings, Networks and Weak Topologies
Czech Academy of Sciences Publication Activity Database
Dow, A.; Junnila, H.; Pelant, Jan
Roč. 53, č. 2 (2006), s. 287-320 ISSN 0025-5793 R&D Projects: GA ČR GA201/97/0216 Institutional research plan: CEZ:AV0Z10190503 Keywords : Banach spaces * weak topologies * networks topologies Subject RIV: BA - General Mathematics
Weak differentiability of product measures
Heidergott, B.F.; Leahu, H.
In this paper, we study cost functions over a finite collection of random variables. For these types of models, a calculus of differentiation is developed that allows us to obtain a closed-form expression for derivatives where "differentiation" has to be understood in the weak sense. The technique
International Nuclear Information System (INIS)
Huterer, Dragan
We study the power of upcoming weak lensing surveys to probe dark energy. Dark energy modifies the distance-redshift relation as well as the matter power spectrum, both of which affect the weak lensing convergence power spectrum. Some dark-energy models predict additional clustering on very large scales, but this probably cannot be detected by weak lensing alone due to cosmic variance. With reasonable prior information on other cosmological parameters, we find that a survey covering 1000 sq deg down to a limiting magnitude of R=27 can impose constraints comparable to those expected from upcoming type Ia supernova and number-count surveys. This result, however, is contingent on the control of both observational and theoretical systematics. Concentrating on the latter, we find that the nonlinear power spectrum of matter perturbations and the redshift distribution of source galaxies both need to be determined accurately in order for weak lensing to achieve its full potential. Finally, we discuss the sensitivity of the three-point statistics to dark energy
Weak pion production from nuclei
Indian Academy of Sciences (India)
effect of Pauli blocking, Fermi motion and renormalization of weak ∆ properties ... Furthermore, the angular distribution and the energy distribution of ... Here ψα(p ) and u(p) are the Rarita Schwinger and Dirac spinors for ∆ and nucleon.
International Nuclear Information System (INIS)
Tauhata, L.; Marques, A.
Energy levels and gamma radiation transitions of Ca 44 are experimentally determined, mainly the weak transition at 564 KeV and 728 KeV. The decay scheme and the method used (coincidence with Ge-Li detector) are also presented [pt
Effects of quenching and partial quenching on penguin matrix elements
Golterman, Maarten; Pallante, Elisabetta
In the calculation of non-leptonic weak decay rates, a "mismatch" arises when the QCD evolution of the relevant weak hamiltonian down to hadronic scales is performed in unquenched QCD, but the hadronic matrix elements are then computed in (partially) quenched lattice QCD. This mismatch arises
Reply to "Comment on `Null weak values and the past of a quantum particle"'
Duprey, Q.; Matzkin, A.
We discuss the preceding Comment [D. Sokolovski, preceding Comment, Phys. Rev. A 97, 046102 (2018), 10.1103/PhysRevA.97.046102] and conclude that the arguments given there against the relevance of null weak values as representing the absence of a system property are not compelling. We give an example in which the transition matrix elements that make the projector weak values vanish are the same ones that suppress detector clicks in strong measurements. Whether weak values are taken to account for the past of a quantum system or not depend on general interpretational commitments of the quantum formalism itself rather than on peculiarities of the weak measurements framework.
N=2 3d-matrix integral with Myers term
International Nuclear Information System (INIS)
Tomino, Dan
An exact matrix integral is evaluated for a 2x2 3-dimensional matrix model with Myers term. We derive weak and strong coupling expansions of the effective action. We also calculate the expectation values of the quadratic and cubic operators. Implications for non-commutative gauge theory on fuzzy sphere are discussed. (author)
Light weakly interacting massive particles
Gelmini, Graciela B.
Light weakly interacting massive particles (WIMPs) are dark matter particle candidates with weak scale interaction with the known particles, and mass in the GeV to tens of GeV range. Hints of light WIMPs have appeared in several dark matter searches in the last decade. The unprecedented possible coincidence into tantalizingly close regions of mass and cross section of four separate direct detection experimental hints and a potential indirect detection signal in gamma rays from the galactic center, aroused considerable interest in our field. Even if these hints did not so far result in a discovery, they have had a significant impact in our field. Here we review the evidence for and against light WIMPs as dark matter candidates and discuss future relevant experiments and observations.
(Weakly) three-dimensional caseology
International Nuclear Information System (INIS)
Pomraning, G.C.
The singular eigenfunction technique of Case for solving one-dimensional planar symmetry linear transport problems is extended to a restricted class of three-dimensional problems. This class involves planar geometry, but with forcing terms (either boundary conditions or internal sources) which are weakly dependent upon the transverse spatial variables. Our analysis involves a singular perturbation about the classic planar analysis, and leads to the usual Case discrete and continuum modes, but modulated by weakly dependent three-dimensional spatial functions. These functions satisfy parabolic differential equations, with a different diffusion coefficient for each mode. Representative one-speed time-independent transport problems are solved in terms of these generalised Case eigenfunctions. Our treatment is very heuristic, but may provide an impetus for more rigorous analysis. (author)
History of the weak interactions
International Nuclear Information System (INIS)
Lee, T.D.
At the 'Jackfest' marking the 65th birthday of Jack Steinberger (see July/August 1986 issue, page 29), T.D. Lee gave an account of the history of the weak interactions. This edited version omits some of Lee's tributes to Steinberger, but retains the impressive insight into the subtleties of a key area of modern physics by one who played a vital role in its development. (orig./HSI).
Weak neutral-current interactions
International Nuclear Information System (INIS)
Barnett, R.M.
The roles of each type of experiment in establishing uniquely the values of the the neutral-current couplings of u and d quarks are analyzed together with their implications for gauge models of the weak and electromagnetic interactions. An analysis of the neutral-current couplings of electrons and of the data based on the assumption that only one Z 0 boson exists is given. Also a model-independent analysis of parity violation experiments is discussed. 85 references
Submanifolds weakly associated with graphs
Indian Academy of Sciences (India)
A CARRIAZO, L M FERN ´ANDEZ and A RODRÍGUEZ-HIDALGO. Department of Geometry and Topology, ..... by means of trees (connected graphs without cycles) and forests (disjoint unions of trees, see [6]) given in [3], by extending it to weak ... CR-submanifold. In this case, every tree is a K2. Finally, Theorem 3.8 of [3] can ...
Chern-Simons couplings for dielectric F-strings in matrix string theory
International Nuclear Information System (INIS)
Brecher, Dominic; Janssen, Bert; Lozano, Yolanda
We compute the non-abelian couplings in the Chern-Simons action for a set of coinciding fundamental strings in both the type IIA and type IIB Matrix string theories. Starting from Matrix theory in a weakly curved background, we construct the linear couplings of closed string fields to type IIA Matrix strings. Further dualities give a type IIB Matrix string theory and a type IIA theory of Matrix strings with winding. (Abstract Copyright[2002], Wiley Periodicals, Inc.)
Gossip and Distributed Kalman Filtering: Weak Consensus Under Weak Detectability
Kar, Soummya; Moura, José M. F.
The paper presents the gossip interactive Kalman filter (GIKF) for distributed Kalman filtering for networked systems and sensor networks, where inter-sensor communication and observations occur at the same time-scale. The communication among sensors is random; each sensor occasionally exchanges its filtering state information with a neighbor depending on the availability of the appropriate network link. We show that under a weak distributed detectability condition: 1. the GIKF error process remains stochastically bounded, irrespective of the instability properties of the random process dynamics; and 2. the network achieves \\emph{weak consensus}, i.e., the conditional estimation error covariance at a (uniformly) randomly selected sensor converges in distribution to a unique invariant measure on the space of positive semi-definite matrices (independent of the initial state.) To prove these results, we interpret the filtered states (estimates and error covariances) at each node in the GIKF as stochastic particles with local interactions. We analyze the asymptotic properties of the error process by studying as a random dynamical system the associated switched (random) Riccati equation, the switching being dictated by a non-stationary Markov chain on the network graph.
Symmetric weak ternary quantum homomorphic encryption schemes
Wang, Yuqi; She, Kun; Luo, Qingbin; Yang, Fan; Zhao, Chao
Based on a ternary quantum logic circuit, four symmetric weak ternary quantum homomorphic encryption (QHE) schemes were proposed. First, for a one-qutrit rotation gate, a QHE scheme was constructed. Second, in view of the synthesis of a general 3 × 3 unitary transformation, another one-qutrit QHE scheme was proposed. Third, according to the one-qutrit scheme, the two-qutrit QHE scheme about generalized controlled X (GCX(m,n)) gate was constructed and further generalized to the n-qutrit unitary matrix case. Finally, the security of these schemes was analyzed in two respects. It can be concluded that the attacker can correctly guess the encryption key with a maximum probability pk = 1/33n, thus it can better protect the privacy of users' data. Moreover, these schemes can be well integrated into the future quantum remote server architecture, and thus the computational security of the users' private quantum information can be well protected in a distributed computing environment.
Planckian axions and the Weak Gravity Conjecture
International Nuclear Information System (INIS)
Bachlechner, Thomas C.; Long, Cody; McAllister, Liam
Several recent works http://dx.doi.org/10.1088/1475-7516/2015/09/020, http://dx.doi.org/10.1007/JHEP08(2015)032, http://dx.doi.org/10.1007/JHEP10(2015)023 have claimed that the Weak Gravity Conjecture (WGC) excludes super-Planckian displacements of axion fields, and hence large-field axion inflation, in the absence of monodromy. We argue that in theories with N≫1 axions, super-Planckian axion diameters D are readily allowed by the WGC. We clarify the nontrivial relationship between the kinetic matrix K — unambiguously defined by its form in a Minkowski-reduced basis — and the diameter of the axion fundamental domain, emphasizing that in general the diameter is not solely determined by the eigenvalues f_1"2≤…≤f_N"2 of K: the orientations of the eigenvectors with respect to the identifications imposed by instantons must be incorporated. In particular, even if one were to impose the condition f_N M_p_l does not immediately imply the existence of unsuppressed higher harmonic contributions to the potential. Finally, we argue that in effective axion-gravity theories, the zero-form version of the WGC can be satisfied by gravitational instantons that make negligible contributions to the potential.
Spatial evolutionary games with weak selection.
Nanda, Mridu; Durrett, Richard
Recently, a rigorous mathematical theory has been developed for spatial games with weak selection, i.e., when the payoff differences between strategies are small. The key to the analysis is that when space and time are suitably rescaled, the spatial model converges to the solution of a partial differential equation (PDE). This approach can be used to analyze all [Formula: see text] games, but there are a number of [Formula: see text] games for which the behavior of the limiting PDE is not known. In this paper, we give rules for determining the behavior of a large class of [Formula: see text] games and check their validity using simulation. In words, the effect of space is equivalent to making changes in the payoff matrix, and once this is done, the behavior of the spatial game can be predicted from the behavior of the replicator equation for the modified game. We say predicted here because in some cases the behavior of the spatial game is different from that of the replicator equation for the modified game. For example, if a rock-paper-scissors game has a replicator equation that spirals out to the boundary, space stabilizes the system and produces an equilibrium.
International Nuclear Information System (INIS)
Goradia, S.G.
Why is gravity weak? Gravity is plagued with this and many other questions. After decades of exhausting work we do not have a clear answer. In view of this fact it will be shown in the following pages that there are reasons for thinking that gravity is just a composite force consisting of the long-range manifestations of short range nuclear forces that are too tiny to be measured at illuminated or long ranges by particle colliders. This is consistent with Einstein's proposal in 1919
International Nuclear Information System (INIS)
Gaillard, M.K.
The properties that may help to identify the two additional quark flavors that are expected to be discovered. These properties are lifetime, branching ratios, selection rules, and lepton decay spectra. It is also noted that CP violation may manifest itself more strongly in heavy particle decays than elsewhere providing a new probe of its origin. The theoretical progress in the understanding of nonleptonic transitions among lighter quarks, nonleptonic K and hyperon decay amplitudes, omega minus and charmed particle decay predictions, and lastly the Kobayashi--Maskawa model for the weak coupling of heavy quarks together with the details of its implications for topology and bottomology are treated. 48 references
Weak consistency and strong paraconsistency
Directory of Open Access Journals (Sweden)
Gemma Robles
Full Text Available In a standard sense, consistency and paraconsistency are understood as, respectively, the absence of any contradiction and as the absence of the ECQ ("E contradictione quodlibet" rule that allows us to conclude any well formed formula from any contradiction. The aim of this paper is to explain the concepts of weak consistency alternative to the standard one, the concepts of paraconsistency related to them and the concept of strong paraconsistency, all of which have been defined by the author together with José M. Méndez.
Electromagnetic weak turbulence theory revisited
Energy Technology Data Exchange (ETDEWEB)
Yoon, P. H. [IPST, University of Maryland, College Park, Maryland 20742 (United States); Ziebell, L. F. [Instituto de Fisica, UFRGS, Porto Alegre, RS (Brazil); Gaelzer, R.; Pavan, J. [Instituto de Fisica e Matematica, UFPel, Pelotas, RS (Brazil)
The statistical mechanical reformulation of weak turbulence theory for unmagnetized plasmas including fully electromagnetic effects was carried out by Yoon [Phys. Plasmas 13, 022302 (2006)]. However, the wave kinetic equation for the transverse wave ignores the nonlinear three-wave interaction that involves two transverse waves and a Langmuir wave, the incoherent analogue of the so-called Raman scattering process, which may account for the third and higher-harmonic plasma emissions. The present paper extends the previous formalism by including such a term.
The finite element response matrix method
International Nuclear Information System (INIS)
Nakata, H.; Martin, W.R.
A new technique is developed with an alternative formulation of the response matrix method implemented with the finite element scheme. Two types of response matrices are generated from the Galerkin solution to the weak form of the diffusion equation subject to an arbitrary current and source. The piecewise polynomials are defined in two levels, the first for the local (assembly) calculations and the second for the global (core) response matrix calculations. This finite element response matrix technique was tested in two 2-dimensional test problems, 2D-IAEA benchmark problem and Biblis benchmark problem, with satisfatory results. The computational time, whereas the current code is not extensively optimized, is of the same order of the well estabilished coarse mesh codes. Furthermore, the application of the finite element technique in an alternative formulation of response matrix method permits the method to easily incorporate additional capabilities such as treatment of spatially dependent cross-sections, arbitrary geometrical configurations, and high heterogeneous assemblies. (Author) [pt
Predictions of baryon form factors for the electromagnetic and weak interaction
International Nuclear Information System (INIS)
Kiehlmann, H.D.
The electromagnetic and weak form factors of the baryon matrix elements (with B the nucleon or the Λ(1232)-resonance) are determined via sumrules by the experimentally known form factors of the nucleon matrix element for momentum transfers 0 2 2 . The operator Jμ denotes either the electromagnetic current or the weak hypercharge-conserving current of the I. class. The sumrules are derived from the superconvergence of properly chosen reaction amplitudes. The results allow an absolute determination of the cross sections of a series of peripheral reactions. An important and interesting consequence for the considered matrix elements of the weak current is that the properties of CVC of PCAC follow from the sumrules without additional assumptions. Finally the predictions of relativistic SU(6)-models are checked. One gets surprisingly a good confirmation of the essential results of these models, the reliability of which has almost been unknown on account of a series of speculative assumptions. (orig.) [de
International Nuclear Information System (INIS)
Chanowitz, M.S.
Prospects for the study of standard model weak interactions at the SSC are reviewed, with emphasis on the unique capability of the SSC to study the mechanism of electroweak symmetry breaking whether the associated new quanta are at the TeV scale or higher. Symmetry breaking by the minimal Higgs mechanism and by related strong interaction dynamical variants is summarized. A set of measurements is outlined that would calibrate the proton structure functions and the backgrounds to new physics. The ability to measure the three weak gauge boson vertex is found to complement LEP II, with measurements extending to larger Q 2 at a comparable statistical level in detectable decays. B factory physics is briefly reviewed as one example of a possible broad program of high statistics studies of sub-TeV scale phenomena. The largest section of the talk is devoted to the possible manifestations of symmetry breaking in the WW and ZZ production cross sections. Some new results are presented bearing on the ability to detect high mass WW and ZZ pairs. The principal conclusion is that although nonstandard model scenarios are typically more forgiving, the capability to study symmetry breaking in the standard model (and in related strong interaction dynamical variants) requires achieving the SSC design goals of √ s,L = 40Tev, 10 33 cm -2 sec -1 . 28 refs., 5 figs
Probing supervoids with weak lensing
Higuchi, Yuichi; Inoue, Kaiki Taro
The cosmic microwave background (CMB) has non-Gaussian features in the temperature fluctuations. An anomalous cold spot surrounded with a hot ring, called the Cold Spot, is one of such features. If a large underdense region (supervoid) resides towards the Cold Spot, we would be able to detect a systematic shape distortion in the images of background source galaxies via weak lensing effect. In order to estimate the detectability of such signals, we used the data of N-body simulations to simulate full-sky ray-tracing of source galaxies. We searched for a most prominent underdense region using the simulated convergence maps smoothed at a scale of 20° and obtained tangential shears around it. The lensing signal expected in a concordant Λ cold dark matter model can be detected at a signal-to-noise ratio S/N ˜ 3. If a supervoid with a radius of ˜200 h-1 Mpc and a density contrast δ0 ˜ -0.3 at the centre resides at a redshift z ˜ 0.2, on-going and near-future weak gravitational lensing surveys would detect a lensing signal with S/N ≳ 4 without resorting to stacking. From the tangential shear profile, we can obtain a constraint on the projected mass distribution of the supervoid.
Efficiency criterion for teleportation via channel matrix, measurement matrix and collapsed matrix
Directory of Open Access Journals (Sweden)
Xin-Wei Zha
Full Text Available In this paper, three kinds of coefficient matrixes (channel matrix, measurement matrix, collapsed matrix associated with the pure state for teleportation are presented, the general relation among channel matrix, measurement matrix and collapsed matrix is obtained. In addition, a criterion for judging whether a state can be teleported successfully is given, depending on the relation between the number of parameter of an unknown state and the rank of the collapsed matrix. Keywords: Channel matrix, Measurement matrix, Collapsed matrix, Teleportation
Inelastic multiple scattering of interacting bosons in weak random potentials
International Nuclear Information System (INIS)
Geiger, Tobias
N-body density matrix of the atomic subspace. This allows us to study the influence of the weak laser fields onto the dynamics of the strongly interacting Rydberg chain, as a function of time. Whereas in the long time limit the N-body density matrix - due to the dephasing by the weak fields - relaxes to a fully mixed state, the dynamics for intermediate times reveals a strong influence of the Rydberg blockade mechanism, a signature of which can also be identified in the intensity scattered off the chain of Rydberg atoms.
Extended biorthogonal matrix polynomials
Directory of Open Access Journals (Sweden)
Ayman Shehata
Full Text Available The pair of biorthogonal matrix polynomials for commutative matrices were first introduced by Varma and Tasdelen in [22]. The main aim of this paper is to extend the properties of the pair of biorthogonal matrix polynomials of Varma and Tasdelen and certain generating matrix functions, finite series, some matrix recurrence relations, several important properties of matrix differential recurrence relations, biorthogonality relations and matrix differential equation for the pair of biorthogonal matrix polynomials J(A,B n (x, k and K(A,B n (x, k are discussed. For the matrix polynomials J(A,B n (x, k, various families of bilinear and bilateral generating matrix functions are constructed in the sequel.
Matrix completion by deep matrix factorization.
Fan, Jicong; Cheng, Jieyu
Conventional methods of matrix completion are linear methods that are not effective in handling data of nonlinear structures. Recently a few researchers attempted to incorporate nonlinear techniques into matrix completion but there still exists considerable limitations. In this paper, a novel method called deep matrix factorization (DMF) is proposed for nonlinear matrix completion. Different from conventional matrix completion methods that are based on linear latent variable models, DMF is on the basis of a nonlinear latent variable model. DMF is formulated as a deep-structure neural network, in which the inputs are the low-dimensional unknown latent variables and the outputs are the partially observed variables. In DMF, the inputs and the parameters of the multilayer neural network are simultaneously optimized to minimize the reconstruction errors for the observed entries. Then the missing entries can be readily recovered by propagating the latent variables to the output layer. DMF is compared with state-of-the-art methods of linear and nonlinear matrix completion in the tasks of toy matrix completion, image inpainting and collaborative filtering. The experimental results verify that DMF is able to provide higher matrix completion accuracy than existing methods do and DMF is applicable to large matrices. Copyright © 2017 Elsevier Ltd. All rights reserved.
Weak KAM for commuting Hamiltonians
International Nuclear Information System (INIS)
Zavidovique, M
For two commuting Tonelli Hamiltonians, we recover the commutation of the Lax–Oleinik semi-groups, a result of Barles and Tourin (2001 Indiana Univ. Math. J. 50 1523–44), using a direct geometrical method (Stoke's theorem). We also obtain a 'generalization' of a theorem of Maderna (2002 Bull. Soc. Math. France 130 493–506). More precisely, we prove that if the phase space is the cotangent of a compact manifold then the weak KAM solutions (or viscosity solutions of the critical stationary Hamilton–Jacobi equation) for G and for H are the same. As a corollary we obtain the equality of the Aubry sets and of the Peierls barrier. This is also related to works of Sorrentino (2009 On the Integrability of Tonelli Hamiltonians Preprint) and Bernard (2007 Duke Math. J. 136 401–20)
Fermi and the Theory of Weak Interactions
Indian Academy of Sciences (India)
IAS Admin
Quantum Field Theory created by Dirac and used by Fermi to describe weak ... of classical electrodynamics (from which the electric field and magnetic field can be obtained .... Universe. However, thanks to weak interactions, this can be done.
Nuclear beta decay and the weak interaction
International Nuclear Information System (INIS)
Kean, D.C.
Short notes are presented on various aspects of nuclear beta decay and weak interactions including: super-allowed transitions, parity violation, interaction strengths, coupling constants, and the current-current formalism of weak interaction. (R.L.)
Weak diffusion limits of dynamic conditional correlation models
DEFF Research Database (Denmark)
Hafner, Christian M.; Laurent, Sebastien; Violante, Francesco
The properties of dynamic conditional correlation (DCC) models are still not entirely understood. This paper fills one of the gaps by deriving weak diffusion limits of a modified version of the classical DCC model. The limiting system of stochastic differential equations is characterized...... by a diffusion matrix of reduced rank. The degeneracy is due to perfect collinearity between the innovations of the volatility and correlation dynamics. For the special case of constant conditional correlations, a non-degenerate diffusion limit can be obtained. Alternative sets of conditions are considered...
Weak production of strangeness at threshold with polarization observables
International Nuclear Information System (INIS)
Baker, O.K.
The differential cross section for the charged current electroweak reaction e → +p → ν → e +Λ → at threshold with polarization observables is presented. The form of the cross section at threshold for the reaction is simplified compared to higher energy. An expression is given for the invariant matrix element appropriate for the reaction when the incident electron is polarized, and the final state hyperon polarization is determined. The energy dependence of the resulting cross section is shown near threshold. Under the right kinematic conditions, there can be a sizeable enhancement in the cross section, making an experimental measurement of the weak axial-vector form factor feasible
Weakly distributive modules. Applications to supplement submodules
Indian Academy of Sciences (India)
Abstract. In this paper, we define and study weakly distributive modules as a proper generalization of distributive modules. We prove that, weakly distributive supplemented modules are amply supplemented. In a weakly distributive supplemented module every submodule has a unique coclosure. This generalizes a result of ...
DEFF Research Database (Denmark)
Petersen, Kaare Brandt; Pedersen, Michael Syskind
Matrix identities, relations and approximations. A desktop reference for quick overview of mathematics of matrices.......Matrix identities, relations and approximations. A desktop reference for quick overview of mathematics of matrices....
Farooque, Mohammad; Yuh, Chao-Yi
A carbonate fuel cell matrix comprising support particles and crack attenuator particles which are made platelet in shape to increase the resistance of the matrix to through cracking. Also disclosed is a matrix having porous crack attenuator particles and a matrix whose crack attenuator particles have a thermal coefficient of expansion which is significantly different from that of the support particles, and a method of making platelet-shaped crack attenuator particles.
Matrix with Prescribed Eigenvectors
Ahmad, Faiz
It is a routine matter for undergraduates to find eigenvalues and eigenvectors of a given matrix. But the converse problem of finding a matrix with prescribed eigenvalues and eigenvectors is rarely discussed in elementary texts on linear algebra. This problem is related to the "spectral" decomposition of a matrix and has important technical…
Indian Academy of Sciences (India)
Much of linear algebra is devoted to reducing a matrix (via similarity or unitary similarity) to another that has lots of zeros. The simplest such theorem is the Schur triangularization theorem. This says that every matrix is unitarily similar to an upper triangular matrix. Our aim here is to show that though it is very easy to prove it ...
A Universe without Weak Interactions
Energy Technology Data Exchange (ETDEWEB)
Harnik, Roni; Kribs, Graham D.; Perez, Gilad
A universe without weak interactions is constructed that undergoes big-bang nucleosynthesis, matter domination, structure formation, and star formation. The stars in this universe are able to burn for billions of years, synthesize elements up to iron, and undergo supernova explosions, dispersing heavy elements into the interstellar medium. These definitive claims are supported by a detailed analysis where this hypothetical ''Weakless Universe'' is matched to our Universe by simultaneously adjusting Standard Model and cosmological parameters. For instance, chemistry and nuclear physics are essentially unchanged. The apparent habitability of the Weakless Universe suggests that the anthropic principle does not determine the scale of electroweak breaking, or even require that it be smaller than the Planck scale, so long as technically natural parameters may be suitably adjusted. Whether the multi-parameter adjustment is realized or probable is dependent on the ultraviolet completion, such as the string landscape. Considering a similar analysis for the cosmological constant, however, we argue that no adjustments of other parameters are able to allow the cosmological constant to raise up even remotely close to the Planck scale while obtaining macroscopic structure. The fine-tuning problems associated with the electroweak breaking scale and the cosmological constant therefore appear to be qualitatively different from the perspective of obtaining a habitable universe.
A Universe without Weak Interactions
International Nuclear Information System (INIS)
Harnik, R
A universe without weak interactions is constructed that undergoes big-bang nucleosynthesis, matter domination, structure formation, and star formation. The stars in this universe are able to burn for billions of years, synthesize elements up to iron, and undergo supernova explosions, dispersing heavy elements into the interstellar medium. These definitive claims are supported by a detailed analysis where this hypothetical ''Weakless Universe'' is matched to our Universe by simultaneously adjusting Standard Model and cosmological parameters. For instance, chemistry and nuclear physics are essentially unchanged. The apparent habitability of the Weakless Universe suggests that the anthropic principle does not determine the scale of electroweak breaking, or even require that it be smaller than the Planck scale, so long as technically natural parameters may be suitably adjusted. Whether the multi-parameter adjustment is realized or probable is dependent on the ultraviolet completion, such as the string landscape. Considering a similar analysis for the cosmological constant, however, we argue that no adjustments of other parameters are able to allow the cosmological constant to raise up even remotely close to the Planck scale while obtaining macroscopic structure. The fine-tuning problems associated with the electroweak breaking scale and the cosmological constant therefore appear to be qualitatively different from the perspective of obtaining a habitable universe
A universe without weak interactions
International Nuclear Information System (INIS)
Harnik, Roni; Kribs, Graham D.; Perez, Gilad
A universe without weak interactions is constructed that undergoes big-bang nucleosynthesis, matter domination, structure formation, and star formation. The stars in this universe are able to burn for billions of years, synthesize elements up to iron, and undergo supernova explosions, dispersing heavy elements into the interstellar medium. These definitive claims are supported by a detailed analysis where this hypothetical ''weakless universe'' is matched to our Universe by simultaneously adjusting standard model and cosmological parameters. For instance, chemistry and nuclear physics are essentially unchanged. The apparent habitability of the weakless universe suggests that the anthropic principle does not determine the scale of electroweak breaking, or even require that it be smaller than the Planck scale, so long as technically natural parameters may be suitably adjusted. Whether the multiparameter adjustment is realized or probable is dependent on the ultraviolet completion, such as the string landscape. Considering a similar analysis for the cosmological constant, however, we argue that no adjustments of other parameters are able to allow the cosmological constant to raise up even remotely close to the Planck scale while obtaining macroscopic structure. The fine-tuning problems associated with the electroweak breaking scale and the cosmological constant therefore appear to be qualitatively different from the perspective of obtaining a habitable universe
Measurements of weak conversion lines
International Nuclear Information System (INIS)
Feoktistov, A.I.; Frantsev, Yu.E.
Described is a new methods for measuring weak conversion lines with the help of the β spectrometer of the π √ 2 type which permits to increase the reliability of the results obtained. According to this method the measurements were carried out by short series with the storage of the information obtained on the punched tape. The spectrometer magnetic field was stabilized during the measuring of the conversion spectra with the help of three nmr recorders. Instead of the dependence of the pulse calculation rate on the magnetic field value was measured the dependence of the calculation rate on the value of the voltage applied between the source and the spectrometer chamber. A short description of the automatic set-up for measuring conversion lines according to the method proposed is given. The main set-up elements are the voltage multiplexer timer, printer, scaler and the pulse analyzer. With the help of the above methods obtained is the K 1035, 8 keV 182 Ta line. It is obtained as a result of the composition of 96 measurement series. Each measurement time constitutes 640 s 12 points are taken on the line
Methodology for analyzing weak spectra
International Nuclear Information System (INIS)
Yankovich, T.L.; Swainson, I.P.
There is considerable interest in quantifying radionuclide transfer between environmental compartments. However, in many cases, it can be a challenge to detect concentrations of gamma-emitting radionuclides due to their low levels in environmental samples. As a result, it is valuable to develop analytical protocols to ensure consistent analysis of the areas under weak peaks. The current study has focused on testing how reproducibly peak areas and baselines can be determined using two analytical approaches. The first approach, which can be carried out using Maestro software, involves extracting net counts under a curve without fitting a functional form to the peak, whereas the second approach, which is used by most other peak fitting programs, determines net counts from spectra by fitting a Gaussian form to the data. It was found that the second approach produces more consistent peak area and baseline measurements, with the ability to de-convolute multiple, overlapping peaks. In addition, programs, such as Peak Fit, which can be used to fit a form to spectral data, often provide goodness of fit analyses, since the Gaussian form can be described using a characteristic equation against which peak data can be tested for their statistical significance. (author)
Constraints on the dark matter and dark energy interactions from weak lensing bispectrum tomography
Energy Technology Data Exchange (ETDEWEB)
An, Rui [School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Feng, Chang [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Wang, Bin, E-mail: firstname.lastname@example.com, E-mail: firstname.lastname@example.com, E-mail: firstname.lastname@example.com [Center for Gravitation and Cosmology, College of Physical Science and Technology, Yangzhou University, Yangzhou 225009 (China)
We estimate uncertainties of cosmological parameters for phenomenological interacting dark energy models using weak lensing convergence power spectrum and bispectrum. We focus on the bispectrum tomography and examine how well the weak lensing bispectrum with tomography can constrain the interactions between dark sectors, as well as other cosmological parameters. Employing the Fisher matrix analysis, we forecast parameter uncertainties derived from weak lensing bispectra with a two-bin tomography and place upper bounds on strength of the interactions between the dark sectors. The cosmic shear will be measured from upcoming weak lensing surveys with high sensitivity, thus it enables us to use the higher order correlation functions of weak lensing to constrain the interaction between dark sectors and will potentially provide more stringent results with other observations combined.
Characterization of organic matrix extracted from fresh water pearls
International Nuclear Information System (INIS)
Ma Yufei; Gao Yonghua; Feng Qingling
Aragonite pearl and vaterite pearl from cultured Hyriopsis cumingii in Zhuji (Zhejiang province, China) were chosen for the study. The matrix proteins were extracted using water and weak acid, and classified as water soluble matrix (WSM), acid soluble matrix (ASM) and acid insoluble matrix (AIM). The proteins from both pearls were characterized by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), X-ray diffraction (XRD) and Fourier transformation infrared spectra (FTIR). The results showed that, AIM of aragonite pearl and vaterite pearl had an ordered structure of α-helix. ASM conformations of these two pearls were different from each other. WSM differed the most between these two pearls. - Research Highlights: → We use a specific method for extracting matrix proteins from aragonite pearl and vaterite pearl respectively. → The matrix proteins are extracted by water and weak acid, and classified as water soluble matrix (WSM), acid soluble matrix (ASM) and acid insoluble matrix (AIM). → AIM of aragonite pearl and vaterite pearl have an ordered structure. ASM conformations of the two pearls are different from each other. WSM differ the most between these two pearls.
Homological properties of modules with finite weak injective and weak flat dimensions
Zhao, Tiwei
In this paper, we define a class of relative derived functors in terms of left or right weak flat resolutions to compute the weak flat dimension of modules. Moreover, we investigate two classes of modules larger than that of weak injective and weak flat modules, study the existence of covers and preenvelopes, and give some applications.
Weak boson emission in hadron collider processes
International Nuclear Information System (INIS)
Baur, U.
The O(α) virtual weak radiative corrections to many hadron collider processes are known to become large and negative at high energies, due to the appearance of Sudakov-like logarithms. At the same order in perturbation theory, weak boson emission diagrams contribute. Since the W and Z bosons are massive, the O(α) virtual weak radiative corrections and the contributions from weak boson emission are separately finite. Thus, unlike in QED or QCD calculations, there is no technical reason for including gauge boson emission diagrams in calculations of electroweak radiative corrections. In most calculations of the O(α) electroweak radiative corrections, weak boson emission diagrams are therefore not taken into account. Another reason for not including these diagrams is that they lead to final states which differ from that of the original process. However, in experiment, one usually considers partially inclusive final states. Weak boson emission diagrams thus should be included in calculations of electroweak radiative corrections. In this paper, I examine the role of weak boson emission in those processes at the Fermilab Tevatron and the CERN LHC for which the one-loop electroweak radiative corrections are known to become large at high energies (inclusive jet, isolated photon, Z+1 jet, Drell-Yan, di-boson, tt, and single top production). In general, I find that the cross section for weak boson emission is substantial at high energies and that weak boson emission and the O(α) virtual weak radiative corrections partially cancel
A review of Indirect Matrix Converter Topologies
Directory of Open Access Journals (Sweden)
Salem Rahmani
Full Text Available Abstract—Matrix Converter (MC is a modern direct AC/AC electrical power converter without dc-link capacitor. MC is operated in four quadrant, assuring a control of the output voltage, amplitude and frequency. The matrix converter has recently attracted significant attention among researchers and it has become increasing attractive for applications of wind energy conversion, military power supplies, induction motor drives, etc. Recently, different MC topologies have been proposed and developed which have their own advantages and disadvantages. Matrix converter can be classified as direct and indirect structures. The direct one has been elaborated in previous work. In this paper the indirect MCs are reviewed. Different characteristics of the indirect MC topologies are mentioned to show the strengths and weaknesses of such converter topologies.
Classical field approach to quantum weak measurements.
Dressel, Justin; Bliokh, Konstantin Y; Nori, Franco
By generalizing the quantum weak measurement protocol to the case of quantum fields, we show that weak measurements probe an effective classical background field that describes the average field configuration in the spacetime region between pre- and postselection boundary conditions. The classical field is itself a weak value of the corresponding quantum field operator and satisfies equations of motion that extremize an effective action. Weak measurements perturb this effective action, producing measurable changes to the classical field dynamics. As such, weakly measured effects always correspond to an effective classical field. This general result explains why these effects appear to be robust for pre- and postselected ensembles, and why they can also be measured using classical field techniques that are not weak for individual excitations of the field.
Instrumental systematics and weak gravitational lensing
International Nuclear Information System (INIS)
Mandelbaum, R.
We present a pedagogical review of the weak gravitational lensing measurement process and its connection to major scientific questions such as dark matter and dark energy. Then we describe common ways of parametrizing systematic errors and understanding how they affect weak lensing measurements. Finally, we discuss several instrumental systematics and how they fit into this context, and conclude with some future perspective on how progress can be made in understanding the impact of instrumental systematics on weak lensing measurements
Fixed points of occasionally weakly biased mappings
Y. Mahendra Singh, M. R. Singh
Common fixed point results due to Pant et al. [Pant et al., Weak reciprocal continuity and fixed point theorems, Ann Univ Ferrara, 57(1), 181-190 (2011)] are extended to a class of non commuting operators called occasionally weakly biased pair[ N. Hussain, M. A. Khamsi A. Latif, Commonfixed points for JH-operators and occasionally weakly biased pairs under relaxed conditions, Nonlinear Analysis, 74, 2133-2140 (2011)]. We also provideillustrative examples to justify the improvements. Abstract....
Robust weak measurements on finite samples
International Nuclear Information System (INIS)
Tollaksen, Jeff
A new weak measurement procedure is introduced for finite samples which yields accurate weak values that are outside the range of eigenvalues and which do not require an exponentially rare ensemble. This procedure provides a unique advantage in the amplification of small nonrandom signals by minimizing uncertainties in determining the weak value and by minimizing sample size. This procedure can also extend the strength of the coupling between the system and measuring device to a new regime
Spin effects in the weak interaction
International Nuclear Information System (INIS)
Freedman, S.J.; Chicago Univ., IL; Chicago Univ., IL
Modern experiments investigating the beta decay of the neutron and light nuclei are still providing important constraints on the theory of the weak interaction. Beta decay experiments are yielding more precise values for allowed and induced weak coupling constants and putting constraints on possible extensions to the standard electroweak model. Here we emphasize the implications of recent experiments to pin down the strengths of the weak vector and axial vector couplings of the nucleon
Weak strange particle production: advantages and difficulties
International Nuclear Information System (INIS)
Angelescu, Tatiana; Baker, O.K.
Electromagnetic strange particle production developed at Jefferson Laboratory was an important source of information on strange particle electromagnetic formfactors and induced and transferred polarization. The high quality of the beam and the detection techniques involved could be an argument for detecting strange particles in weak interactions and answer questions about cross sections, weak formfactors, neutrino properties, which have not been investigated yet. The paper analyses some aspects related to the weak lambda production and detection with the Hall C facilities at Jefferson Laboratory and the limitations in measuring the weak interaction quantities. (authors)
On the distribution of eigenvalues of certain matrix ensembles
International Nuclear Information System (INIS)
Bogomolny, E.; Bohigas, O.; Pato, M.P.
Invariant random matrix ensembles with weak confinement potentials of the eigenvalues, corresponding to indeterminate moment problems, are investigated. These ensembles are characterized by the fact that the mean density of eigenvalues tends to a continuous function with increasing matrix dimension contrary to the usual cases where it grows indefinitely. It is demonstrated that the standard asymptotic formulae are not applicable in these cases and that the asymptotic distribution of eigenvalues can deviate from the classical ones. (author)
Parallelism in matrix computations
Gallopoulos, Efstratios; Sameh, Ahmed H
This book is primarily intended as a research monograph that could also be used in graduate courses for the design of parallel algorithms in matrix computations. It assumes general but not extensive knowledge of numerical linear algebra, parallel architectures, and parallel programming paradigms. The book consists of four parts: (I) Basics; (II) Dense and Special Matrix Computations; (III) Sparse Matrix Computations; and (IV) Matrix functions and characteristics. Part I deals with parallel programming paradigms and fundamental kernels, including reordering schemes for sparse matrices. Part II is devoted to dense matrix computations such as parallel algorithms for solving linear systems, linear least squares, the symmetric algebraic eigenvalue problem, and the singular-value decomposition. It also deals with the development of parallel algorithms for special linear systems such as banded ,Vandermonde ,Toeplitz ,and block Toeplitz systems. Part III addresses sparse matrix computations: (a) the development of pa...
International Nuclear Information System (INIS)
Strobel, E.L.
Given the many conflicting experimental results, examination is made of the neutrino mass matrix in order to determine possible masses and mixings. It is assumed that the Dirac mass matrix for the electron, muon, and tau neutrinos is similar in form to those of the quarks and charged leptons, and that the smallness of the observed neutrino masses results from the Gell-Mann-Ramond-Slansky mechanism. Analysis of masses and mixings for the neutrinos is performed using general structures for the Majorana mass matrix. It is shown that if certain tentative experimental results concerning the neutrino masses and mixing angles are confirmed, significant limitations may be placed on the Majorana mass matrix. The most satisfactory simple assumption concerning the Majorana mass matrix is that it is approximately proportional to the Dirac mass matrix. A very recent experimental neutrino mass result and its implications are discussed. Some general properties of matrices with structure similar to the Dirac mass matrices are discussed
Electromagnetic and weak observables in the context of the shell model
International Nuclear Information System (INIS)
Wildenthal, B.H.
Wave functions for A = 17-39 nuclei have been obtained from diagonalizations of a single Hamiltonian formulation in the complete sd-shell configuration space for each NTJ system. These wave functions are used to generate the one-body density matrices corresponding to weak and electromagnetic transitions and moments. These densities are combined with different assumptions for the single-particle matrix elements of the weak and electromagnetic operators to produce theoretical matrix elements. The predictions are compared with experiment to determine, in some ''linearly dependent'' fashion, the correctness of the wave functions themselves, the optimum values of the single-particle matrix elements, and the viability of the overall shell-model formulation. (author)
S-parameters for weakly excited slots
DEFF Research Database (Denmark)
Albertsen, Niels Christian
A simple approach to account for parasitic effects in weakly excited slots cut in the broad wall of a rectangular waveguide is proposed......A simple approach to account for parasitic effects in weakly excited slots cut in the broad wall of a rectangular waveguide is proposed...
Low-energy Electro-weak Reactions
International Nuclear Information System (INIS)
Gazit, Doron
Chiral effective field theory (EFT) provides a systematic and controlled approach to low-energy nuclear physics. Here, we use chiral EFT to calculate low-energy weak Gamow-Teller transitions. We put special emphasis on the role of two-body (2b) weak currents within the nucleus and discuss their applications in predicting physical observables.
Weak interaction: past answers, present questions
International Nuclear Information System (INIS)
Ne'eman, Y.
A historical sketch of the weak interaction is presented. From beta ray to pion decay, the V-A theory of Marshak and Sudarshan, CVC principle of equivalence, universality as an algebraic condition, PCAC, renormalized weak Hamiltonian in the rehabilitation of field theory, and some current issues are considered in this review. 47 references
Weak measurements with a qubit meter
DEFF Research Database (Denmark)
Wu, Shengjun; Mølmer, Klaus
We derive schemes to measure the so-called weak values of quantum system observables by coupling of the system to a qubit meter system. We highlight, in particular, the meaning of the imaginary part of the weak values, and show how it can be measured directly on equal footing with the real part...
Optimization of strong and weak coordinates
Swart, M.; Bickelhaupt, F.M.
We present a new scheme for the geometry optimization of equilibrium and transition state structures that can be used for both strong and weak coordinates. We use a screening function that depends on atom-pair distances to differentiate strong coordinates from weak coordinates. This differentiation
DEFF Research Database (Denmark)
Hansen, Kristoffer Arnsfelt; Ibsen-Jensen, Rasmus; Podolskii, Vladimir V.
For matrix games we study how small nonzero probability must be used in optimal strategies. We show that for image win–lose–draw games (i.e. image matrix games) nonzero probabilities smaller than image are never needed. We also construct an explicit image win–lose game such that the unique optimal...
DEFF Research Database (Denmark)
Schneider, Jesper Wiborg; Borlund, Pia
The present two-part article introduces matrix comparison as a formal means for evaluation purposes in informetric studies such as cocitation analysis. In the first part, the motivation behind introducing matrix comparison to informetric studies, as well as two important issues influencing such c...
Saleem, M
The Unitarity of the CKM matrix is examined in the light of the latest available accurate data. The analysis shows that a conclusive result cannot be derived at present. Only more precise data can determine whether the CKM matrix opens new vistas beyond the standard model or not.
International Nuclear Information System (INIS)
Markowski, Adam S.; Mannan, M. Sam
A risk matrix is a mechanism to characterize and rank process risks that are typically identified through one or more multifunctional reviews (e.g., process hazard analysis, audits, or incident investigation). This paper describes a procedure for developing a fuzzy risk matrix that may be used for emerging fuzzy logic applications in different safety analyses (e.g., LOPA). The fuzzification of frequency and severity of the consequences of the incident scenario are described which are basic inputs for fuzzy risk matrix. Subsequently using different design of risk matrix, fuzzy rules are established enabling the development of fuzzy risk matrices. Three types of fuzzy risk matrix have been developed (low-cost, standard, and high-cost), and using a distillation column case study, the effect of the design on final defuzzified risk index is demonstrated
International Nuclear Information System (INIS)
Baron, Jorge H.; Rivera, S.S.
The so-called vulnerability matrix is used in the evaluation part of the probabilistic safety assessment for a nuclear power plant, during the containment event trees calculations. This matrix is established from what is knows as Numerical Categories for Engineering Judgement. This matrix is usually established with numerical values obtained with traditional arithmetic using the set theory. The representation of this matrix with fuzzy numbers is much more adequate, due to the fact that the Numerical Categories for Engineering Judgement are better represented with linguistic variables, such as 'highly probable', 'probable', 'impossible', etc. In the present paper a methodology to obtain a Fuzzy Vulnerability Matrix is presented, starting from the recommendations on the Numerical Categories for Engineering Judgement. (author)
Weak Solution and Weakly Uniformly Bounded Solution of Impulsive Heat Equations Containing "Maximum" Temperature
Directory of Open Access Journals (Sweden)
Oyelami, Benjamin Oyediran
Full Text Available In this paper, criteria for the existence of weak solutions and uniformly weak bounded solution of impulsive heat equation containing maximum temperature are investigated and results obtained. An example is given for heat flow system with impulsive temperature using maximum temperature simulator and criteria for the uniformly weak bounded of solutions of the system are obtained.
Diagnosis of functional (psychogenic paresis and weakness
Directory of Open Access Journals (Sweden)
Savkov V.S.
Full Text Available Functional (conversion neurological symptoms represent one of the most common situations faced by neurologists in their everyday practice. Among them, acute or subacute functional weakness may mimic very prevalent conditions such as stroke or traumatic injury. In the diagnosis of functional weakness, although elements of the history are helpful, physical signs are often of crucial importance in the diagnosis and positive signs are as important as absence of signs of disease. Hence, accurate and reliable positive signs of functional weakness are valuable for obtaining timely diagnosis and treatment, making it possible to avoid unnecessary or invasive tests and procedures up to thrombolysis. Functional weakness commonly presents as weakness of an entire limb, paraparesis, or hemiparesis, with observable or demonstrable inconsistencies and non-anatomic accompaniments. Documentation of limb movements during sleep, the arm drop test, the Babinski's trunk-thigh test, Hoover tests, the Sonoo abductor test, and various dynamometer tests can provide useful bedside diagnostic information on functional weakness. We therefore present here a brief overview of the positive neurological signs of functional weakness available, both in the lower and in the upper limbs; but none should be used in isolation and must be interpreted in the overall context of the presentation. It should be borne in mind that a patient may have both a functional and an organic disorder.
Azimuthal Seismic Amplitude Variation with Offset and Azimuth Inversion in Weakly Anisotropic Media with Orthorhombic Symmetry
Pan, Xinpeng; Zhang, Guangzhi; Yin, Xingyao
Seismic amplitude variation with offset and azimuth (AVOaz) inversion is well known as a popular and pragmatic tool utilized to estimate fracture parameters. A single set of vertical fractures aligned along a preferred horizontal direction embedded in a horizontally layered medium can be considered as an effective long-wavelength orthorhombic medium. Estimation of Thomsen's weak-anisotropy (WA) parameters and fracture weaknesses plays an important role in characterizing the orthorhombic anisotropy in a weakly anisotropic medium. Our goal is to demonstrate an orthorhombic anisotropic AVOaz inversion approach to describe the orthorhombic anisotropy utilizing the observable wide-azimuth seismic reflection data in a fractured reservoir with the assumption of orthorhombic symmetry. Combining Thomsen's WA theory and linear-slip model, we first derive a perturbation in stiffness matrix of a weakly anisotropic medium with orthorhombic symmetry under the assumption of small WA parameters and fracture weaknesses. Using the perturbation matrix and scattering function, we then derive an expression for linearized PP-wave reflection coefficient in terms of P- and S-wave moduli, density, Thomsen's WA parameters, and fracture weaknesses in such an orthorhombic medium, which avoids the complicated nonlinear relationship between the orthorhombic anisotropy and azimuthal seismic reflection data. Incorporating azimuthal seismic data and Bayesian inversion theory, the maximum a posteriori solutions of Thomsen's WA parameters and fracture weaknesses in a weakly anisotropic medium with orthorhombic symmetry are reasonably estimated with the constraints of Cauchy a priori probability distribution and smooth initial models of model parameters to enhance the inversion resolution and the nonlinear iteratively reweighted least squares strategy. The synthetic examples containing a moderate noise demonstrate the feasibility of the derived orthorhombic anisotropic AVOaz inversion method, and the
International Nuclear Information System (INIS)
Krenciglowa, E.M.; Kung, C.L.; Kuo, T.T.S.; Osnes, E.; and Department of Physics, State University of New York at Stony Brook, Stony Brook, New York 11794)
Different definitions of the reaction matrix G appropriate to the calculation of nuclear structure are reviewed and discussed. Qualitative physical arguments are presented in support of a two-step calculation of the G-matrix for finite nuclei. In the first step the high-energy excitations are included using orthogonalized plane-wave intermediate states, and in the second step the low-energy excitations are added in, using harmonic oscillator intermediate states. Accurate calculations of G-matrix elements for nuclear structure calculations in the Aapprox. =18 region are performed following this procedure and treating the Pauli exclusion operator Q 2 /sub p/ by the method of Tsai and Kuo. The treatment of Q 2 /sub p/, the effect of the intermediate-state spectrum and the energy dependence of the reaction matrix are investigated in detail. The present matrix elements are compared with various matrix elements given in the literature. In particular, close agreement is obtained with the matrix elements calculated by Kuo and Brown using approximate methods
Matrix Metalloproteinase Enzyme Family
Directory of Open Access Journals (Sweden)
Ozlem Goruroglu Ozturk
Full Text Available Matrix metalloproteinases play an important role in many biological processes such as embriogenesis, tissue remodeling, wound healing, and angiogenesis, and in some pathological conditions such as atherosclerosis, arthritis and cancer. Currently, 24 genes have been identified in humans that encode different groups of matrix metalloproteinase enzymes. This review discuss the members of the matrix metalloproteinase family and their substrate specificity, structure, function and the regulation of their enzyme activity by tissue inhibitors. [Archives Medical Review Journal 2013; 22(2.000: 209-220
Matrix groups for undergraduates
Tapp, Kristopher
Matrix groups touch an enormous spectrum of the mathematical arena. This textbook brings them into the undergraduate curriculum. It makes an excellent one-semester course for students familiar with linear and abstract algebra and prepares them for a graduate course on Lie groups. Matrix Groups for Undergraduates is concrete and example-driven, with geometric motivation and rigorous proofs. The story begins and ends with the rotations of a globe. In between, the author combines rigor and intuition to describe basic objects of Lie theory: Lie algebras, matrix exponentiation, Lie brackets, and maximal tori.
Eves, Howard
The usefulness of matrix theory as a tool in disciplines ranging from quantum mechanics to psychometrics is widely recognized, and courses in matrix theory are increasingly a standard part of the undergraduate curriculum.This outstanding text offers an unusual introduction to matrix theory at the undergraduate level. Unlike most texts dealing with the topic, which tend to remain on an abstract level, Dr. Eves' book employs a concrete elementary approach, avoiding abstraction until the final chapter. This practical method renders the text especially accessible to students of physics, engineeri
Probabilistic Cosmological Mass Mapping from Weak Lensing Shear
Energy Technology Data Exchange (ETDEWEB)
Schneider, M. D.; Dawson, W. A. [Lawrence Livermore National Laboratory, Livermore, CA 94551 (United States); Ng, K. Y. [University of California, Davis, Davis, CA 95616 (United States); Marshall, P. J. [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94035 (United States); Meyers, J. E. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Bard, D. J., E-mail: email@example.com, E-mail: firstname.lastname@example.com, E-mail: firstname.lastname@example.com, E-mail: email@example.com, E-mail: firstname.lastname@example.com [National Energy Research Scientific Computing Center, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720-8150 (United States)
We infer gravitational lensing shear and convergence fields from galaxy ellipticity catalogs under a spatial process prior for the lensing potential. We demonstrate the performance of our algorithm with simulated Gaussian-distributed cosmological lensing shear maps and a reconstruction of the mass distribution of the merging galaxy cluster Abell 781 using galaxy ellipticities measured with the Deep Lens Survey. Given interim posterior samples of lensing shear or convergence fields on the sky, we describe an algorithm to infer cosmological parameters via lens field marginalization. In the most general formulation of our algorithm we make no assumptions about weak shear or Gaussian-distributed shape noise or shears. Because we require solutions and matrix determinants of a linear system of dimension that scales with the number of galaxies, we expect our algorithm to require parallel high-performance computing resources for application to ongoing wide field lensing surveys.
Fixation times in evolutionary games under weak selection
International Nuclear Information System (INIS)
Altrock, Philipp M; Traulsen, Arne
In evolutionary game dynamics, reproductive success increases with the performance in an evolutionary game. If strategy A performs better than strategy B, strategy A will spread in the population. Under stochastic dynamics, a single mutant will sooner or later take over the entire population or go extinct. We analyze the mean exit times (or average fixation times) associated with this process. We show analytically that these times depend on the payoff matrix of the game in an amazingly simple way under weak selection, i.e. strong stochasticity: the payoff difference Δπ is a linear function of the number of A individuals i, Δπ=u i+v. The unconditional mean exit time depends only on the constant term v. Given that a single A mutant takes over the population, the corresponding conditional mean exit time depends only on the density dependent term u. We demonstrate this finding for two commonly applied microscopic evolutionary processes.
Thermodynamics of a Bose-Einstein condensate with weak disorder
International Nuclear Information System (INIS)
Falco, G. M.; Pelster, A.; Graham, R.
We consider the thermodynamics of a homogeneous superfluid dilute Bose gas in the presence of weak quenched disorder. Following the zero-temperature approach of Huang and Meng, we diagonalize the Hamiltonian of a dilute Bose gas in an external random δ-correlated potential by means of a Bogoliubov transformation. We extend this approach to finite temperature by combining the Popov and the many-body T-matrix approximations. This approach permits us to include the quasiparticle interactions within this temperature range. We derive the disorder-induced shifts of the Bose-Einstein critical temperature and of the temperature for the onset of superfluidity by approaching the transition points from below, i.e., from the superfluid phase. Our results lead to a phase diagram consistent with that of the finite-temperature theory of Lopatin and Vinokur which was based on the replica method, and in which the transition points were approached from above
Weak entropy inequalities and entropic convergence
Institute of Scientific and Technical Information of China (English)
A criterion for algebraic convergence of the entropy is presented and an algebraic convergence result for the entropy of an exclusion process is improved. A weak entropy inequality is considered and its relationship to entropic convergence is discussed.
Current problems in the weak interactions
International Nuclear Information System (INIS)
Pais, A.
Some reasons are discussed showing why the recent SU(2) x U(1) gauge theory of weak and electromagnetic interactions is not a complete theory of these interactions, Lepton theory, charm, and the CP problem are considered. 60 references
From Suitable Weak Solutions to Entropy Viscosity
Guermond, Jean-Luc; Pasquetti, Richard; Popov, Bojan
This paper focuses on the notion of suitable weak solutions for the three-dimensional incompressible Navier-Stokes equations and discusses the relevance of this notion to Computational Fluid Dynamics. The purpose of the paper is twofold (i
Subsidy Competition for FDI: Fierce or Weak?
Tomáš Havránek
The objective of this paper is to empirically assess the recently introduced models of subsidy competition based on the classical oligopoly theories, using both cross-sectional and panel data. Three crucial scenarios (including coordination, weak competition, and fierce competition) are tested employing OLS, iteratively re-weighted least squares, fixed effects, and Blundell-Bond estimator. The results suggest that none of the scenarios can be strongly supported—although there is some weak sup...
About some distinguishing features of weak interactions
International Nuclear Information System (INIS)
Beshtoev, Kh.M.
It is shown that, in contrast to strong and electromagnetic theories, additive conserved numbers (such as lepton, aromatic and another numbers) and γ 5 anomaly do not appear in the standard weak interaction theory. It means that in this interaction the additive numbers cannot be conserved. These results are the consequence of specific character of the weak interaction: the right components of spinors do not participate in this interaction. The schemes of violation of the aromatic and lepton numbers were considered
Weak limits for quantum random walks
International Nuclear Information System (INIS)
Grimmett, Geoffrey; Janson, Svante; Scudo, Petra F.
We formulate and prove a general weak limit theorem for quantum random walks in one and more dimensions. With X n denoting position at time n, we show that X n /n converges weakly as n→∞ to a certain distribution which is absolutely continuous and of bounded support. The proof is rigorous and makes use of Fourier transform methods. This approach simplifies and extends certain preceding derivations valid in one dimension that make use of combinatorial and path integral methods
Drift waves in a weakly ionized plasma
DEFF Research Database (Denmark)
Popovic, M.; Melchior, H.
A dispersion relation for low frequency drift waves in a weakly ionized plasma has been derived, and through numerical calculations the effect of collisions between the charged and the neutral particles is estimated.......A dispersion relation for low frequency drift waves in a weakly ionized plasma has been derived, and through numerical calculations the effect of collisions between the charged and the neutral particles is estimated....
Attending to weak signals: the leader's challenge.
Kerfoot, Karlene
Halverson and Isham (2003) quote sources that report the accidental death rate of simply being in a hospital is " ... four hundred times more likely than your risk of death from traveling by train, forty times higher than driving a car, and twenty times higher than flying in a commercial aircraft" (p. 13). High-reliability organizations such as nuclear power plants and aircraft carriers have been pioneers in the business of recognizing weak signals. Weike and Sutcliffe (2001) note that high-reliability organizations distinguish themselves from others because of their mindfulness which enables them to see the significance of weak signals and to give strong interventions to weak signals. To act mindfully, these organizations have an underlying mental model of continually updating, anticipating, and focusing the possibility of failure using the intelligence that weak signals provides. Much of what happens is unexpected in health care. However, with a culture that is continually looking for weak signals, and intervenes and rescues when these signals are detected, the unexpected happens less often. This is the epitome of how leaders can build a culture of safety that focuses on recognizing the weak signals to manage the unforeseen.
Czerwinski, Michael; Spence, Jason R
Recently in Nature, Gjorevski et al. (2016) describe a fully defined synthetic hydrogel that mimics the extracellular matrix to support in vitro growth of intestinal stem cells and organoids. The hydrogel allows exquisite control over the chemical and physical in vitro niche and enables identification of regulatory properties of the matrix. Copyright © 2017 Elsevier Inc. All rights reserved.
The Matrix Organization Revisited
DEFF Research Database (Denmark)
Gattiker, Urs E.; Ulhøi, John Parm
This paper gives a short overview of matrix structure and technology management. It outlines some of the characteristics and also points out that many organizations may actualy be hybrids (i.e. mix several ways of organizing to allocate resorces effectively).......This paper gives a short overview of matrix structure and technology management. It outlines some of the characteristics and also points out that many organizations may actualy be hybrids (i.e. mix several ways of organizing to allocate resorces effectively)....
[A SWOT (strengths, weaknesses, opportunities, threats) analysis of the current immunization program in Zhejiang Province].
He, Han-Qing; Ling, Luo-Ya; Xu, Xu-Qing
To know the status of Immunization program in Zhejiang Province. The investigation on immunization program in zhejiang province was conducted, and the SWOT analysis was corducted to make a comprehensive evaluation. 11 cities, 22 counties and 44 towns were investigated in this study, and the current immunization program in Zhejiang province were explored by SWOT analysis. The SWOT Matrix, includes SO (strength-opportunity), ST (strength-threat), WO (weakness-opportunity) and WT (weakness-threat) can apply to make optimal strategy for the development of expanded program on immunization.
Weak-microcavity organic light-emitting diodes with improved light out-coupling.
Cho, Sang-Hwan; Song, Young-Woo; Lee, Joon-gu; Kim, Yoon-Chang; Lee, Jong Hyuk; Ha, Jaeheung; Oh, Jong-Suk; Lee, So Young; Lee, Sun Young; Hwang, Kyu Hwan; Zang, Dong-Sik; Lee, Yong-Hee
We propose and demonstrate weak-microcavity organic light-emitting diode (OLED) displays with improved light-extraction and viewing-angle characteristics. A single pair of low- and high-index layers is inserted between indium tin oxide (ITO) and a glass substrate. The electroluminescent (EL) efficiencies of discrete red, green, and blue weak-microcavity OLEDs are enhanced by 56%, 107%, and 26%, respectively, with improved color purity. Moreover, full-color passive-matrix bottom-emitting OLED displays are fabricated by employing low-index layers of two thicknesses. As a display, the EL efficiency of white color was 27% higher than that of a conventional OLED display.
Koo, H.; Falsetta, M.L.; Klein, M.I.
Many infectious diseases in humans are caused or exacerbated by biofilms. Dental caries is a prime example of a biofilm-dependent disease, resulting from interactions of microorganisms, host factors, and diet (sugars), which modulate the dynamic formation of biofilms on tooth surfaces. All biofilms have a microbial-derived extracellular matrix as an essential constituent. The exopolysaccharides formed through interactions between sucrose- (and starch-) and Streptococcus mutans-derived exoenzymes present in the pellicle and on microbial surfaces (including non-mutans) provide binding sites for cariogenic and other organisms. The polymers formed in situ enmesh the microorganisms while forming a matrix facilitating the assembly of three-dimensional (3D) multicellular structures that encompass a series of microenvironments and are firmly attached to teeth. The metabolic activity of microbes embedded in this exopolysaccharide-rich and diffusion-limiting matrix leads to acidification of the milieu and, eventually, acid-dissolution of enamel. Here, we discuss recent advances concerning spatio-temporal development of the exopolysaccharide matrix and its essential role in the pathogenesis of dental caries. We focus on how the matrix serves as a 3D scaffold for biofilm assembly while creating spatial heterogeneities and low-pH microenvironments/niches. Further understanding on how the matrix modulates microbial activity and virulence expression could lead to new approaches to control cariogenic biofilms. PMID:24045647
Flavour symmetry restoration and kaon weak matrix elements in quenched twisted mass QCD
Dimopoulos, P; Palombi, Filippo; Peña, C; Sint, S; Vladikas, A
We simulate two variants of quenched twisted mass QCD (tmQCD), with degenerate Wilson quarks of masses equal to or heavier than half the strange quark mass. We use Ward identities in order to measure the twist angles of the theory and thus check the quality of the tuning of mass parameters to a physics condition which stays constant as the lattice spacing is varied. Flavour symmetry breaking in tmQCD is studied in a framework of two fully twisted and two standard Wilson quark flavours, tuned to be degenerate in the continuum. Comparing pseudoscalar masses, obtained from connected quark diagrams made of tmQCD and/or standard Wilson quark propagators, we confirm that flavour symmetry breaking effects, which are at most 5%, decrease as we approach the continuum limit. We also compute the pseudoscalar decay constant in the continuum limit, with reduced systematics. As a consequence of improved tuning of the mass parameters at $\\beta = 6.1$, we reanalyse our previous $B_K$ results. Our main phenomenological findin...
Manifestation of neutral weak currents in the e+e-annihilation
International Nuclear Information System (INIS)
Rekalo, M.P.; Gakh, G.I.; Korzh, A.P.
The polarization effects, caused by the interference between electromagnetic and neutral weak currents mechanisms, are investigated for the inclusive V-meson production in the e + e - - annihilation. The polarization states of the V-meson are discussed in detail. We use three decriptions of the V-meson polarization. They are: the 4-vector of spin and quadrupole tensor description, the polarization vector description and the density matrix, formalis. The collision of the polarized beams is characterized by the virtual photon and Z-boson density matrix in the helicity representation
Enhancing QKD security with weak measurements
Farinholt, Jacob M.; Troupe, James E.
Publisher's Note: This paper, originally published on 10/24/2016, was replaced with a corrected/revised version on 11/8/2016. If you downloaded the original PDF but are unable to access the revision, please contact SPIE Digital Library Customer Service for assistance. In the late 1980s, Aharonov and colleagues developed the notion of a weak measurement of a quantum observable that does not appreciably disturb the system.1, 2 The measurement results are conditioned on both the pre-selected and post-selected state of the quantum system. While any one measurement reveals very little information, by making the same measurement on a large ensemble of identically prepared pre- and post-selected (PPS) states and averaging the results, one may obtain what is known as the weak value of the observable with respect to that PPS ensemble. Recently, weak measurements have been proposed as a method of assessing the security of QKD in the well-known BB84 protocol.3 This weak value augmented QKD protocol (WV-QKD) works by additionally requiring the receiver, Bob, to make a weak measurement of a particular observable prior to his strong measurement. For the subset of measurement results in which Alice and Bob's measurement bases do not agree, the weak measurement results can be used to detect any attempt by an eavesdropper, Eve, to correlate her measurement results with Bob's. Furthermore, the well-known detector blinding attacks, which are known to perfectly correlate Eve's results with Bob's without being caught by conventional BB84 implementations, actually make the eavesdropper more visible in the new WV-QKD protocol. In this paper, we will introduce the WV-QKD protocol and discuss its generalization to the 6-state single qubit protocol. We will discuss the types of weak measurements that are optimal for this protocol, and compare the predicted performance of the 6- and 4-state WV-QKD protocols.
Weak interactions in astrophysics and cosmology
International Nuclear Information System (INIS)
Taylor, R.J.
There ar many problems in astrophysics and cosmology in which the form of the weak interactions, their strength or the number of weakly interacting particles, is very important. It is possible that astronomical observations may give some information about the weak interactions. In the conventional hot big bang cosmological theory the number of leptons with associated neutrinos influences the speed of expansion of the Universe and the chemical composition of pre-galactic matter. The strength of the weak interaction, as exemplified by the half-life of the neutron, has a similar effect. In addition, the form of the weak interactions will determine how effectively neutrino viscosity can smooth out irregularities in the early Universe. Because neutrinos have a very long mean free path, they can escape from the central region of stars whereas photons can only escape from the surface. In late stages of stellar evolution, neutrino luminosity is often believed to be much greater than photon luminosity. This can both accelerate the cooling of dying stars and influence the stages of stellar evolution leading to the onset of supernova explosions. In pre-super-novae it is even possible that very dense stellar cores can be opaque to neutrinos and that the absorption or scattering of neutrinos can cause the explosion. These results depend crucially on the form of the weak interactions, with the discovery of neutral currents being very important. Until the solar neutrino experiment has been reconciled with theory, the possible role of uncertainties in the weak interactions cannot be ignored. (author)
Importance of weak minerals on earthquake mechanics
Kaneki, S.; Hirono, T.
The role of weak minerals such as smectite and talc on earthquake mechanics is one of the important issues, and has been debated for recent several decades. Traditionally weak minerals in fault have been reported to weaken fault strength causing from its low frictional resistance. Furthermore, velocity-strengthening behavior of such weak mineral (talc) is considered to responsible for fault creep (aseismic slip) in the San Andreas fault. In contrast, recent studies reported that large amount of weak smectite in the Japan Trench could facilitate gigantic seismic slip during the 2011 Tohoku-oki earthquake. To investigate the role of weak minerals on rupture propagation process and magnitude of slip, we focus on the frictional properties of carbonaceous materials (CMs), which is the representative weak materials widely distributed in and around the convergent boundaries. Field observation and geochemical analyses revealed that graphitized CMs-layer is distributed along the slip surface of a fossil plate-subduction fault. Laboratory friction experiments demonstrated that pure quartz, bulk mixtures with bituminous coal (1 wt.%), and quartz with layered coal samples exhibited almost similar frictional properties (initial, yield, and dynamic friction). However, mixtures of quartz (99 wt.%) and layered graphite (1 wt.%) showed significantly lower initial and yield friction coefficient (0.31 and 0.50, respectively). Furthermore, the stress ratio S, defined as (yield stress-initial stress)/(initial stress-dynamic stress), increased in layered graphite samples (1.97) compared to quartz samples (0.14). Similar trend was observed in smectite-rich fault gouge. By referring the reported results of dynamic rupture propagation simulation using S ratio of 1.4 (typical value for the Japan Trench) and 2.0 (this study), we confirmed that higher S ratio results in smaller slip distance by approximately 20 %. On the basis of these results, we could conclude that weak minerals have lower
Directory of Open Access Journals (Sweden)
V. D. Petrenko
Full Text Available Purpose. This article provides: the question of the sustainability of the subgrade on a weak base is considered in the paper. It is proposed to use the method of jet grouting. Investigation of the possibility of a weak base has an effect on the overall deformation of the subgrade; the identification and optimization of the parameters of subgrade based on studies using numerical simulation. Methodology. The theoretical studies of the stress-strain state of the base and subgrade embankment by modeling in the software package LIRA have been conducted to achieve this goal. Findings. After making the necessary calculations perform building fields of a subsidence, borders cramped thickness, bed's coefficients of Pasternak and Winkler. The diagrams construction of vertical stress performs at any point of load application. Also, using the software system may perform peer review subsidence, rolls railroad tracks in natural and consolidated basis. Originality. For weak soils is the most appropriate nonlinear model of the base with the existing areas of both elastic and limit equilibrium, mixed problem of the theory of elasticity and plasticity. Practical value. By increasing the load on the weak base as a result of the second track construction, adds embankment or increasing axial load when changing the rolling stock process of sedimentation and consolidation may continue again. Therefore, one of the feasible and promising options for the design and reconstruction of embankments on weak bases is to strengthen the bases with the help of jet grouting. With the expansion of the railway infrastructure, increasing speed and weight of the rolling stock is necessary to ensure the stability of the subgrade on weak bases. LIRA software package allows you to perform all the necessary calculations for the selection of a proper way of strengthening weak bases.
The Problem of Weak Governments and Weak Societies in Eastern Europe
Directory of Open Access Journals (Sweden)
Marko Grdešić
Full Text Available This paper argues that, for Eastern Europe, the simultaneous presence of weak governments and weak societies is a crucial obstacle which must be faced by analysts and reformers. The understanding of other normatively significant processes will be deficient without a consciousness-raising deliberation on this problem and its implications. This paper seeks to articulate the "relational" approach to state and society. In addition, the paper lays out a typology of possible patterns of relationship between state and society, dependent on whether the state is weak or strong and whether society is weak or strong. Comparative data are presented in order to provide an empirical support for the theses. Finally, the paper outlines two reform approaches which could enable breaking the vicious circle emerging in the context of weak governments and weak societies.
Geometric phase topology in weak measurement
Samlan, C. T.; Viswanathan, Nirmal K.
The geometric phase visualization proposed by Bhandari (R Bhandari 1997 Phys. Rep. 281 1-64) in the ellipticity-ellipse orientation basis of the polarization ellipse of light is implemented to understand the geometric aspects of weak measurement. The weak interaction of a pre-selected state, acheived via spin-Hall effect of light (SHEL), results in a spread in the polarization ellipticity (η) or ellipse orientation (χ) depending on the resulting spatial or angular shift, respectively. The post-selection leads to the projection of the η spread in the complementary χ basis results in the appearance of a geometric phase with helical phase topology in the η - χ parameter space. By representing the weak measurement on the Poincaré sphere and using Jones calculus, the complex weak value and the geometric phase topology are obtained. This deeper understanding of the weak measurement process enabled us to explore the techniques' capabilities maximally, as demonstrated via SHEL in two examples—external reflection at glass-air interface and transmission through a tilted half-wave plate.
Weak KAM theory for a weakly coupled system of Hamilton–Jacobi equations
Figalli, Alessio; Gomes, Diogo A.; Marcon, Diego
Here, we extend the weak KAM and Aubry–Mather theories to optimal switching problems. We consider three issues: the analysis of the calculus of variations problem, the study of a generalized weak KAM theorem for solutions of weakly coupled systems of Hamilton–Jacobi equations, and the long-time behavior of time-dependent systems. We prove the existence and regularity of action minimizers, obtain necessary conditions for minimality, extend Fathi's weak KAM theorem, and describe the asymptotic limit of the generalized Lax–Oleinik semigroup. © 2016, Springer-Verlag Berlin Heidelberg.
Weak KAM theory for a weakly coupled system of Hamilton–Jacobi equations
Figalli, Alessio
Here, we extend the weak KAM and Aubry–Mather theories to optimal switching problems. We consider three issues: the analysis of the calculus of variations problem, the study of a generalized weak KAM theorem for solutions of weakly coupled systems of Hamilton–Jacobi equations, and the long-time behavior of time-dependent systems. We prove the existence and regularity of action minimizers, obtain necessary conditions for minimality, extend Fathi's weak KAM theorem, and describe the asymptotic limit of the generalized Lax–Oleinik semigroup. © 2016, Springer-Verlag Berlin Heidelberg.
Bhatia, Rajendra
This book is an outcome of the Indo-French Workshop on Matrix Information Geometries (MIG): Applications in Sensor and Cognitive Systems Engineering, which was held in Ecole Polytechnique and Thales Research and Technology Center, Palaiseau, France, in February 23-25, 2011. The workshop was generously funded by the Indo-French Centre for the Promotion of Advanced Research (IFCPAR). During the event, 22 renowned invited french or indian speakers gave lectures on their areas of expertise within the field of matrix analysis or processing. From these talks, a total of 17 original contribution or state-of-the-art chapters have been assembled in this volume. All articles were thoroughly peer-reviewed and improved, according to the suggestions of the international referees. The 17 contributions presented are organized in three parts: (1) State-of-the-art surveys & original matrix theory work, (2) Advanced matrix theory for radar processing, and (3) Matrix-based signal processing applications.
Weakly supervised classification in high energy physics
International Nuclear Information System (INIS)
Dery, Lucio Mwinmaarong; Nachman, Benjamin; Rubbo, Francesco; Schwartzman, Ariel
As machine learning algorithms become increasingly sophisticated to exploit subtle features of the data, they often become more dependent on simulations. This paper presents a new approach called weakly supervised classification in which class proportions are the only input into the machine learning algorithm. Using one of the most challenging binary classification tasks in high energy physics — quark versus gluon tagging — we show that weakly supervised classification can match the performance of fully supervised algorithms. Furthermore, by design, the new algorithm is insensitive to any mis-modeling of discriminating features in the data by the simulation. Weakly supervised classification is a general procedure that can be applied to a wide variety of learning problems to boost performance and robustness when detailed simulations are not reliable or not available.
Weakly supervised classification in high energy physics
Energy Technology Data Exchange (ETDEWEB)
Dery, Lucio Mwinmaarong [Physics Department, Stanford University,Stanford, CA, 94305 (United States); Nachman, Benjamin [Physics Division, Lawrence Berkeley National Laboratory,1 Cyclotron Rd, Berkeley, CA, 94720 (United States); Rubbo, Francesco; Schwartzman, Ariel [SLAC National Accelerator Laboratory, Stanford University,2575 Sand Hill Rd, Menlo Park, CA, 94025 (United States)
As machine learning algorithms become increasingly sophisticated to exploit subtle features of the data, they often become more dependent on simulations. This paper presents a new approach called weakly supervised classification in which class proportions are the only input into the machine learning algorithm. Using one of the most challenging binary classification tasks in high energy physics — quark versus gluon tagging — we show that weakly supervised classification can match the performance of fully supervised algorithms. Furthermore, by design, the new algorithm is insensitive to any mis-modeling of discriminating features in the data by the simulation. Weakly supervised classification is a general procedure that can be applied to a wide variety of learning problems to boost performance and robustness when detailed simulations are not reliable or not available.
Efficient quantum computing with weak measurements
International Nuclear Information System (INIS)
Lund, A P
Projective measurements with high quantum efficiency are often assumed to be required for efficient circuit-based quantum computing. We argue that this is not the case and show that the fact that they are not required was actually known previously but was not deeply explored. We examine this issue by giving an example of how to perform the quantum-ordering-finding algorithm efficiently using non-local weak measurements considering that the measurements used are of bounded weakness and some fixed but arbitrary probability of success less than unity is required. We also show that it is possible to perform the same computation with only local weak measurements, but this must necessarily introduce an exponential overhead.
Weak layer fracture: facets and depth hoar
Directory of Open Access Journals (Sweden)
I. Reiweger
Full Text Available Understanding failure initiation within weak snow layers is essential for modeling and predicting dry-snow slab avalanches. We therefore performed laboratory experiments with snow samples containing a weak layer consisting of either faceted crystals or depth hoar. During these experiments the samples were loaded with different loading rates and at various tilt angles until fracture. The strength of the samples decreased with increasing loading rate and increasing tilt angle. Additionally, we took pictures of the side of four samples with a high-speed video camera and calculated the displacement using a particle image velocimetry (PIV algorithm. The fracture process within the weak layer could thus be observed in detail. Catastrophic failure started due to a shear fracture just above the interface between the depth hoar layer and the underlying crust.
Weak lensing in the Dark Energy Survey
Troxel, Michael
I will present the current status of weak lensing results from the Dark Energy Survey (DES). DES will survey 5000 square degrees in five photometric bands (grizY), and has already provided a competitive weak lensing catalog from Science Verification data covering just 3% of the final survey footprint. I will summarize the status of shear catalog production using observations from the first year of the survey and discuss recent weak lensing science results from DES. Finally, I will report on the outlook for future cosmological analyses in DES including the two-point cosmic shear correlation function and discuss challenges that DES and future surveys will face in achieving a control of systematics that allows us to take full advantage of the available statistical power of our shear catalogs.
Weak self-adjoint differential equations
International Nuclear Information System (INIS)
Gandarias, M L
The concepts of self-adjoint and quasi self-adjoint equations were introduced by Ibragimov (2006 J. Math. Anal. Appl. 318 742-57; 2007 Arch. ALGA 4 55-60). In Ibragimov (2007 J. Math. Anal. Appl. 333 311-28), a general theorem on conservation laws was proved. In this paper, we generalize the concept of self-adjoint and quasi self-adjoint equations by introducing the definition of weak self-adjoint equations. We find a class of weak self-adjoint quasi-linear parabolic equations. The property of a differential equation to be weak self-adjoint is important for constructing conservation laws associated with symmetries of the differential equation. (fast track communication)
On weakly D-differentiable operators
DEFF Research Database (Denmark)
Christensen, Erik
Let DD be a self-adjoint operator on a Hilbert space HH and aa a bounded operator on HH. We say that aa is weakly DD-differentiable, if for any pair of vectors ξ,ηξ,η from HH the function 〈eitDae−itDξ,η〉〈eitDae−itDξ,η〉 is differentiable. We give an elementary example of a bounded operator aa......, such that aa is weakly DD-differentiable, but the function eitDae−itDeitDae−itD is not uniformly differentiable. We show that weak DD-differentiability may be characterized by several other properties, some of which are related to the commutator (Da−aD)...
Strong effects in weak nonleptonic decays
International Nuclear Information System (INIS)
Wise, M.B.
In this report the weak nonleptonic decays of kaons and hyperons are examined with the hope of gaining insight into a recently proposed mechanism for the ΔI = 1/2 rule. The effective Hamiltonian for ΔS = 1 weak nonleptonic decays and that for K 0 -anti K 0 mixing are calculated in the six-quark model using the leading logarithmic approximation. These are used to examine the CP violation parameters of the kaon system. It is found that if Penguin-type diagrams make important contributions to K → ππ decay amplitudes then upcoming experiments may be able to distinguish the six-quark model for CP violation from the superweak model. The weak radiative decays of hyperons are discussed with an emphasis on what they can teach us about hyperon nonleptonic decays and the ΔI = 1/2 rule
Precision cosmology with weak gravitational lensing
Hearin, Andrew P.
In recent years, cosmological science has developed a highly predictive model for the universe on large scales that is in quantitative agreement with a wide range of astronomical observations. While the number and diversity of successes of this model provide great confidence that our general picture of cosmology is correct, numerous puzzles remain. In this dissertation, I analyze the potential of planned and near future galaxy surveys to provide new understanding of several unanswered questions in cosmology, and address some of the leading challenges to this observational program. In particular, I study an emerging technique called cosmic shear, the weak gravitational lensing produced by large scale structure. I focus on developing strategies to optimally use the cosmic shear signal observed in galaxy imaging surveys to uncover the physics of dark energy and the early universe. In chapter 1 I give an overview of a few unsolved mysteries in cosmology and I motivate weak lensing as a cosmological probe. I discuss the use of weak lensing as a test of general relativity in chapter 2 and assess the threat to such tests presented by our uncertainty in the physics of galaxy formation. Interpreting the cosmic shear signal requires knowledge of the redshift distribution of the lensed galaxies. This redshift distribution will be significantly uncertain since it must be determined photometrically. In chapter 3 I investigate the influence of photometric redshift errors on our ability to constrain dark energy models with weak lensing. The ability to study dark energy with cosmic shear is also limited by the imprecision in our understanding of the physics of gravitational collapse. In chapter 4 I present the stringent calibration requirements on this source of uncertainty. I study the potential of weak lensing to resolve a debate over a long-standing anomaly in CMB measurements in chapter 5. Finally, in chapter 6 I summarize my findings and conclude with a brief discussion of my
Extrapolating Weak Selection in Evolutionary Games
Wu, Bin; García, Julián; Hauert, Christoph; Traulsen, Arne
In evolutionary games, reproductive success is determined by payoffs. Weak selection means that even large differences in game outcomes translate into small fitness differences. Many results have been derived using weak selection approximations, in which perturbation analysis facilitates the derivation of analytical results. Here, we ask whether results derived under weak selection are also qualitatively valid for intermediate and strong selection. By "qualitatively valid" we mean that the ranking of strategies induced by an evolutionary process does not change when the intensity of selection increases. For two-strategy games, we show that the ranking obtained under weak selection cannot be carried over to higher selection intensity if the number of players exceeds two. For games with three (or more) strategies, previous examples for multiplayer games have shown that the ranking of strategies can change with the intensity of selection. In particular, rank changes imply that the most abundant strategy at one intensity of selection can become the least abundant for another. We show that this applies already to pairwise interactions for a broad class of evolutionary processes. Even when both weak and strong selection limits lead to consistent predictions, rank changes can occur for intermediate intensities of selection. To analyze how common such games are, we show numerically that for randomly drawn two-player games with three or more strategies, rank changes frequently occur and their likelihood increases rapidly with the number of strategies . In particular, rank changes are almost certain for , which jeopardizes the predictive power of results derived for weak selection. PMID:24339769
Weak Acid Ionization Constants and the Determination of Weak Acid-Weak Base Reaction Equilibrium Constants in the General Chemistry Laboratory
Nyasulu, Frazier; McMills, Lauren; Barlag, Rebecca
A laboratory to determine the equilibrium constants of weak acid negative weak base reactions is described. The equilibrium constants of component reactions when multiplied together equal the numerical value of the equilibrium constant of the summative reaction. The component reactions are weak acid ionization reactions, weak base hydrolysis…
Praeger, Cheryl; Tao, Terence
MATRIX is Australia's international, residential mathematical research institute. It facilitates new collaborations and mathematical advances through intensive residential research programs, each lasting 1-4 weeks. This book is a scientific record of the five programs held at MATRIX in its first year, 2016: Higher Structures in Geometry and Physics (Chapters 1-5 and 18-21); Winter of Disconnectedness (Chapter 6 and 22-26); Approximation and Optimisation (Chapters 7-8); Refining C*-Algebraic Invariants for Dynamics using KK-theory (Chapters 9-13); Interactions between Topological Recursion, Modularity, Quantum Invariants and Low-dimensional Topology (Chapters 14-17 and 27). The MATRIX Scientific Committee selected these programs based on their scientific excellence and the participation rate of high-profile international participants. Each program included ample unstructured time to encourage collaborative research; some of the longer programs also included an embedded conference or lecture series. The artic...
Energy Technology Data Exchange (ETDEWEB)
Pan, Feng [Los Alamos National Laboratory; Kasiviswanathan, Shiva [Los Alamos National Laboratory
In the matrix interdiction problem, a real-valued matrix and an integer k is given. The objective is to remove k columns such that the sum over all rows of the maximum entry in each row is minimized. This combinatorial problem is closely related to bipartite network interdiction problem which can be applied to prioritize the border checkpoints in order to minimize the probability that an adversary can successfully cross the border. After introducing the matrix interdiction problem, we will prove the problem is NP-hard, and even NP-hard to approximate with an additive n{gamma} factor for a fixed constant {gamma}. We also present an algorithm for this problem that achieves a factor of (n-k) mUltiplicative approximation ratio.
DEFF Research Database (Denmark)
Frandsen, Gudmund Skovbjerg; Frandsen, Peter Frands
We consider maintaining information about the rank of a matrix under changes of the entries. For n×n matrices, we show an upper bound of O(n1.575) arithmetic operations and a lower bound of Ω(n) arithmetic operations per element change. The upper bound is valid when changing up to O(n0.575) entries...... in a single column of the matrix. We also give an algorithm that maintains the rank using O(n2) arithmetic operations per rank one update. These bounds appear to be the first nontrivial bounds for the problem. The upper bounds are valid for arbitrary fields, whereas the lower bound is valid for algebraically...... closed fields. The upper bound for element updates uses fast rectangular matrix multiplication, and the lower bound involves further development of an earlier technique for proving lower bounds for dynamic computation of rational functions....
Pérez López, César
MATLAB is a high-level language and environment for numerical computation, visualization, and programming. Using MATLAB, you can analyze data, develop algorithms, and create models and applications. The language, tools, and built-in math functions enable you to explore multiple approaches and reach a solution faster than with spreadsheets or traditional programming languages, such as C/C++ or Java. MATLAB Matrix Algebra introduces you to the MATLAB language with practical hands-on instructions and results, allowing you to quickly achieve your goals. Starting with a look at symbolic and numeric variables, with an emphasis on vector and matrix variables, you will go on to examine functions and operations that support vectors and matrices as arguments, including those based on analytic parent functions. Computational methods for finding eigenvalues and eigenvectors of matrices are detailed, leading to various matrix decompositions. Applications such as change of bases, the classification of quadratic forms and ...
Weak hadronic currents in compensation theory
International Nuclear Information System (INIS)
Pappas, R.C.
Working within the framework of a compensation theory of strong and weak interactions, it is shown that: (1) an axial vector baryon number current can be included in the weak current algebra if certain restrictions on the K-meson strong couplings are relaxed; (2) the theory does not permit the introduction of strange currents of the chiral form V + A; and (3) the assumption that the superweak currents of the theory cannot contain certain CP conserving terms can be justified on the basis of compensation requirements
Weak interactions of the b quark
International Nuclear Information System (INIS)
Branco, G.C.; Mohapatra, R.N.
In weak-interaction models with two charged W bosons of comparable mass, there exists a novel possibility for the weak interactions of the b quark, in which the (u-barb)/sub R/ current occurs with maximal strength. It is noted that multimuon production in e + e - annihilation at above Q 2 > or approx. = (12 GeV) 2 will distinguish this scheme from the conventional one. We also present a Higgs system that leads naturally to this type of coupling, in a class of gauge models
Fast measure proceeding of weak currents
International Nuclear Information System (INIS)
Taieb, J.
The process of fast measure of the weak currents that we are going to describe briefly apply worthy of the provided currents by the sources to elevated value internal resistance, as it is the case for the ionization chamber, the photocells, mass spectroscopic tubes. The problem to measure weak currents is essentially a problem of amplifier and of input circuit. We intended to achieve a whole amplifier and input circuit with advanced performances, meaning that for a measured celerity we wanted to have an signal/noise ratio the most important as in the classic systems and for a same report signal/noise a more quickly done measure. (M.B.) [fr
A Continuation Method for Weakly Kannan Maps
Directory of Open Access Journals (Sweden)
Ariza-Ruiz David
Full Text Available The first continuation method for contractive maps in the setting of a metric space was given by Granas. Later, Frigon extended Granas theorem to the class of weakly contractive maps, and recently Agarwal and O'Regan have given the corresponding result for a certain type of quasicontractions which includes maps of Kannan type. In this note we introduce the concept of weakly Kannan maps and give a fixed point theorem, and then a continuation method, for this class of maps.
From Suitable Weak Solutions to Entropy Viscosity
Guermond, Jean-Luc
This paper focuses on the notion of suitable weak solutions for the three-dimensional incompressible Navier-Stokes equations and discusses the relevance of this notion to Computational Fluid Dynamics. The purpose of the paper is twofold (i) to recall basic mathematical properties of the three-dimensional incompressible Navier-Stokes equations and to show how they might relate to LES (ii) to introduce an entropy viscosity technique based on the notion of suitable weak solution and to illustrate numerically this concept. © 2010 Springer Science+Business Media, LLC.
Weak form factors of beauty baryons
International Nuclear Information System (INIS)
Ivanov, M.A.; Lyubovitskij, V.E.
Full analysis of semileptonic decays of beauty baryons with J p =1/2 2 and J p =3/2 2 into charmed ones within the Quark Confinement Model is reported. Weak form factors and decay rates are calculated. Also the heavy quark limit m Q →∞ (Isgur-Wise symmetry) is examined. The weak heavy-baryon form factors in the Isgur-Wise limit and 1/m Q -corrections to them are computered. The Ademollo-Gatto theorem is spin-flavour symmetry of heavy quarks is checked. 33 refs.; 1 fig.; 9 tabs
Weak interactions at high energies. [Lectures, review
Energy Technology Data Exchange (ETDEWEB)
Ellis, J.
Review lectures are presented on the phenomenological implications of the modern spontaneously broken gauge theories of the weak and electromagnetic interactions, and some observations are made about which high energy experiments probe what aspects of gauge theories. Basic quantum chromodynamics phenomenology is covered including momentum dependent effective quark distributions, the transverse momentum cutoff, search for gluons as sources of hadron jets, the status and prospects for the spectroscopy of fundamental fermions and how fermions may be used to probe aspects of the weak and electromagnetic gauge theory, studies of intermediate vector bosons, and miscellaneous possibilities suggested by gauge theories from the Higgs bosons to speculations about proton decay. 187 references. (JFP)
Shock waves in weakly compressed granular media.
van den Wildenberg, Siet; van Loo, Rogier; van Hecke, Martin
We experimentally probe nonlinear wave propagation in weakly compressed granular media and observe a crossover from quasilinear sound waves at low impact to shock waves at high impact. We show that this crossover impact grows with the confining pressure P0, whereas the shock wave speed is independent of P0-two hallmarks of granular shocks predicted recently. The shocks exhibit surprising power law attenuation, which we model with a logarithmic law implying that shock dissipation is weak and qualitatively different from other granular dissipation mechanisms. We show that elastic and potential energy balance in the leading part of the shocks.
Categorization of States Beyond Strong and Weak
Directory of Open Access Journals (Sweden)
Peter Tikuisis
Full Text Available The discourse on poor state performers has suffered from widely varying definitions on what distinguishes certain weak states from others. Indices that rank states from strong to weak conceal important distinctions that can adversely affect intervention policy. This deficiency is addressed by grouping states according to their performance on three dimensions of statehood: authority, legitimacy, and capacity. The resultant categorization identifies brittle states that are susceptible to regime change, impoverished states often considered as aid darlings, and fragile states that experience disproportionately high levels of violent internal conflict. It also provides a quantifiable means to analyze transitions from one state type to another for more insightful intervention policy.
Theoretical status of weak and electromagnetic interactions
Energy Technology Data Exchange (ETDEWEB)
Pandit, L. K.
An extended simple version of the Weinberg gauge model is proposed to bring together weak and electromagnetic interactions under one theory. The essential features of the standard SU/sub 2/ (operating on)U/sub 1/ gauge scheme with four leptons and four quark flavours is recalled. Charged-current and neutral current interactions are described. Non-leptonic decays of strange particles are studied. The treatment is extended to 6-leptons and 6-quark flavours. The short comings of this model are discussed. Speculations on the unification of strong, weak and electromagnetic interactions are made.
CPT non-invariance and weak interactions
International Nuclear Information System (INIS)
Hsu, J.P.
In this talk, I will describe a possible violation of CPT invariance in the domain of weak interactions. One can construct a model of weak interactions which, in order to be consistent with all experimental data, must violate CPT maximally. The model predicts many specific results for decay processes which could be tested in the planned neutral hyperon beam or neutrino beam at NAL. The motivations and the physical idea in the model are explained and the implications of the model are discussed. (U.S.)
Hohn, Franz E
This complete and coherent exposition, complemented by numerous illustrative examples, offers readers a text that can teach by itself. Fully rigorous in its treatment, it offers a mathematically sound sequencing of topics. The work starts with the most basic laws of matrix algebra and progresses to the sweep-out process for obtaining the complete solution of any given system of linear equations - homogeneous or nonhomogeneous - and the role of matrix algebra in the presentation of useful geometric ideas, techniques, and terminology.Other subjects include the complete treatment of the structur
International Nuclear Information System (INIS)
Brown, T.W.
The same complex matrix model calculates both tachyon scattering for the c=1 non-critical string at the self-dual radius and certain correlation functions of half-BPS operators in N=4 super- Yang-Mills. It is dual to another complex matrix model where the couplings of the first model are encoded in the Kontsevich-like variables of the second. The duality between the theories is mirrored by the duality of their Feynman diagrams. Analogously to the Hermitian Kontsevich- Penner model, the correlation functions of the second model can be written as sums over discrete points in subspaces of the moduli space of punctured Riemann surfaces. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Brown, T.W.
The same complex matrix model calculates both tachyon scattering for the c=1 non-critical string at the self-dual radius and certain correlation functions of half-BPS operators in N=4 super- Yang-Mills. It is dual to another complex matrix model where the couplings of the first model are encoded in the Kontsevich-like variables of the second. The duality between the theories is mirrored by the duality of their Feynman diagrams. Analogously to the Hermitian Kontsevich- Penner model, the correlation functions of the second model can be written as sums over discrete points in subspaces of the moduli space of punctured Riemann surfaces. (orig.)
A weak balance: the contribution of muscle weakness to postural instability and falls.
Horlings, G.C.; Engelen, B.G.M. van; Allum, J.H.J.; Bloem, B.R.
Muscle strength is a potentially important factor contributing to postural control. In this article, we consider the influence of muscle weakness on postural instability and falling. We searched the literature for research evaluating muscle weakness as a risk factor for falls in community-dwelling
Weakly nonlocal symplectic structures, Whitham method and weakly nonlocal symplectic structures of hydrodynamic type
International Nuclear Information System (INIS)
Maltsev, A Ya
We consider the special type of field-theoretical symplectic structures called weakly nonlocal. The structures of this type are, in particular, very common for integrable systems such as KdV or NLS. We introduce here the special class of weakly nonlocal symplectic structures which we call weakly nonlocal symplectic structures of hydrodynamic type. We investigate then the connection of such structures with the Whitham averaging method and propose the procedure of 'averaging' the weakly nonlocal symplectic structures. The averaging procedure gives the weakly nonlocal symplectic structure of hydrodynamic type for the corresponding Whitham system. The procedure also gives 'action variables' corresponding to the wave numbers of m-phase solutions of the initial system which give the additional conservation laws for the Whitham system
Weak organic acid stress in Bacillus subtilis
ter Beek, A.S.
Weak organic acids are commonly used food preservatives that protect food products from bacterial contamination. A variety of spore-forming bacterial species pose a serious problem to the food industry by causing extensive food spoilage or even food poisoning. Understanding the mechanisms of
Common Fixed Points for Weakly Compatible Maps
Indian Academy of Sciences (India)
The purpose of this paper is to prove a common fixed point theorem, from the class of compatible continuous maps to a larger class of maps having weakly compatible maps without appeal to continuity, which generalized the results of Jungck [3], Fisher [1], Kang and Kim [8], Jachymski [2], and Rhoades [9].
Weak MSO: automata and expressiveness modulo bisimilarity
Carreiro, F.; Facchini, A.; Venema, Y.; Zanasi, F.
We prove that the bisimulation-invariant fragment of weak monadic second-order logic (WMSO) is equivalent to the fragment of the modal μ-calculus where the application of the least fixpoint operator μp.φ is restricted to formulas φ that are continuous in p. Our proof is automata-theoretic in nature;
Weak lensing probes of modified gravity
International Nuclear Information System (INIS)
Schmidt, Fabian
We study the effect of modifications to general relativity on large-scale weak lensing observables. In particular, we consider three modified gravity scenarios: f(R) gravity, the Dvali-Gabadadze-Porrati model, and tensor-vector-scalar theory. Weak lensing is sensitive to the growth of structure and the relation between matter and gravitational potentials, both of which will in general be affected by modified gravity. Restricting ourselves to linear scales, we compare the predictions for galaxy-shear and shear-shear correlations of each modified gravity cosmology to those of an effective dark energy cosmology with the same expansion history. In this way, the effects of modified gravity on the growth of perturbations are separated from the expansion history. We also propose a test which isolates the matter-potential relation from the growth factor and matter power spectrum. For all three modified gravity models, the predictions for galaxy and shear correlations will be discernible from those of dark energy with very high significance in future weak lensing surveys. Furthermore, each model predicts a measurably distinct scale dependence and redshift evolution of galaxy and shear correlations, which can be traced back to the physical foundations of each model. We show that the signal-to-noise for detecting signatures of modified gravity is much higher for weak lensing observables as compared to the integrated Sachs-Wolfe effect, measured via the galaxy-cosmic microwave background cross-correlation.
Weak contractions via $\\lambda$-sequences
Agyingi, Collins Amburo; Gaba, Yaé Ulrich
In this note, we discuss common fixed point for a family of self mapping defined on a metric type space and satisfying a weakly contractive condition. In our development, we make use of the $\\lambda$-sequence approach and also of a certain class of real valued maps. We derive some implications for self-mappings on quasi-pseudometric type spaces.
Reducing Weak to Strong Bisimilarity in CCP
Directory of Open Access Journals (Sweden)
Andrés Aristizábal
Full Text Available Concurrent constraint programming (ccp is a well-established model for concurrency that singles out the fundamental aspects of asynchronous systems whose agents (or processes evolve by posting and querying (partial information in a global medium. Bisimilarity is a standard behavioural equivalence in concurrency theory. However, only recently a well-behaved notion of bisimilarity for ccp, and a ccp partition refinement algorithm for deciding the strong version of this equivalence have been proposed. Weak bisimiliarity is a central behavioural equivalence in process calculi and it is obtained from the strong case by taking into account only the actions that are observable in the system. Typically, the standard partition refinement can also be used for deciding weak bisimilarity simply by using Milner's reduction from weak to strong bisimilarity; a technique referred to as saturation. In this paper we demonstrate that, because of its involved labeled transitions, the above-mentioned saturation technique does not work for ccp. We give an alternative reduction from weak ccp bisimilarity to the strong one that allows us to use the ccp partition refinement algorithm for deciding this equivalence.
Weak radiative baryonic decays of B mesons
International Nuclear Information System (INIS)
Kohara, Yoji
Weak radiative baryonic B decays B→B 1 B 2 -barγ are studied under the assumption of the short-distance b→sγ electromagnetic penguin transition dominance. The relations among the decay rates of various decay modes are derived
Weak NNM couplings and nuclear parity violation
International Nuclear Information System (INIS)
Holstein, B.R.
After many years of careful theoretical and experimental study of nuclear parity violation, rough empirical values for weak parity violation nucleon-nucleon-meson vertices have been deduced. We address some of the physics which has been learned from this effort and show that it has implications for work going on outside this field. (author)
Weak universality in inhomogeneous Ising quantum chains
International Nuclear Information System (INIS)
Karevski, Dragi
The Ising quantum chain with arbitrary coupling distribution {λ i } leading to an anisotropic scaling is considered. The smallest gap of the chain is connected to the surface magnetization by the relation Λ 1 = m s ({λ i })m s ({λ -1 i }). For some aperiodic distribution {λ i }, a weak universality of the critical behaviour is found. (letter to the editor)
Broken color symmetry and weak currents
International Nuclear Information System (INIS)
Stech, B.
Broken colour symmetry predicts a very rich spectrum of new particles. If broken colour is relevant at all, charged psi-particles should be found in particular at the 4 GeV region. For the weak hadronic currents no completely satisfactory suggestion exists. Broken colour symmetry describes qualitatively several of the new effects observed recently. (BJ) [de
Solitons and Weakly Nonlinear Waves in Plasmas
DEFF Research Database (Denmark)
Pécseli, Hans
Theoretical descriptions of solitons and weakly nonlinear waves propagating in plasma media are reviewed, with particular attention to the Korteweg-de Vries (KDV) equation and the Nonlinear Schrödinger equation (NLS). The modifications of these basic equations due to the effects of resonant...
Efficient bootstrap with weakly dependent processes
Bravo, Francesco; Crudu, Federico
The efficient bootstrap methodology is developed for overidentified moment conditions models with weakly dependent observation. The resulting bootstrap procedure is shown to be asymptotically valid and can be used to approximate the distributions of t-statistics, the J-statistic for overidentifying
Weak equivalence classes of complex vector bundles
Czech Academy of Sciences Publication Activity Database
Le, Hong-Van
LXXVII, č. 1 (2008), s. 23-30 ISSN 0862-9544 R&D Projects: GA AV ČR IAA100190701 Institutional research plan: CEZ:AV0Z10190503 Keywords : chern classes * complex Grassmannians weak equivalence Subject RIV: BA - General Mathematics
Gauge theories of the weak interactions
International Nuclear Information System (INIS)
Quinn, H.
Two lectures are presented on the Weinberg--Salam--Glashow--Iliopoulos--Maiani gauge theory for weak interactions. An attempt is made to give some impressions of the generality of this model, how it was developed, variations found in the literature, and the status of the standard model. 21 references
Electric properties of weakly nonideal plasmas
Energy Technology Data Exchange (ETDEWEB)
Guenther, K; Radtke, R
The progress in theory as well as in diagnostics and measurement during the last fifteen years is reviewed. Starting from the transport theory of ideal plasmas physically justified corrections are introduced which allow the quantitative calculation of the transport properties of weakly nonideal plasmas. Essential coefficients and numerical data of the electrical conductivity for plasmas of technical importance are given in tables and diagrams.
Localization on weakly disordered Cayley tree
International Nuclear Information System (INIS)
Brezini, A.; Olivier, G.
The localization model of Kumar et al. is critically re-examined for the approximation γ → 0, which describes weak disorder. By using an improved method of approximation, we have studied the displacement of the band and the mobility edges and compared the result of Kumar et al. and Abou-Chacra et al. in the light of the present approximation. (author)
Studying dark matter haloes with weak lensing
Velander, Malin Barbro Margareta
Our Universe is comprised not only of normal matter but also of unknown components: dark matter and dark energy. This Thesis recounts studies of dark matter haloes, using a technique known as weak gravitational lensing, in order to learn more about the nature of these dark components. The haloes
Completely continuous and weakly completely continuous abstract ...
Indian Academy of Sciences (India)
An algebra A is called right completely continuous (right weakly completely continuous) ... Moreover, some applications of these results in group algebras are .... A linear subspace S(G) of L1(G) is said to be a Segal algebra, if it satisfies the.
Collisional properties of weakly bound heteronuclear dimers
Marcelis, B.; Kokkelmans, S.J.J.M.F.; Shlyapnikov, G.V.; Petrov, D.S.
We consider collisional properties of weakly bound heteronuclear molecules (dimers) formed in a two-species mixture of atoms with a large mass difference. We focus on dimers containing light fermionic atoms as they manifest collisional stability due to an effective dimer-dimer repulsion originating
Quantum mechanical calculations on weakly interacting complexes
Heijmen, T.G.A.
Symmetry-adapted perturbation theory (SAPT) has been applied to compute the intermolecular potential energy surfaces and the interaction-induced electrical properties of weakly interacting complexes. Asymptotic (large R) expressions have been derived for the contributions to the collision-induced
Weak-interaction rates in stellar conditions
Sarriguren, Pedro
Weak-interaction rates, including β-decay and electron captures, are studied in several mass regions at various densities and temperatures of astrophysical interest. In particular, we study odd-A nuclei in the pf-shell region, which are involved in presupernova formations. Weak rates are relevant to understand the late stages of the stellar evolution, as well as the nucleosynthesis of heavy nuclei. The nuclear structure involved in the weak processes is studied within a quasiparticle proton-neutron random-phase approximation with residual interactions in both particle-hole and particle-particle channels on top of a deformed Skyrme Hartree-Fock mean field with pairing correlations. First, the energy distributions of the Gamow-Teller strength are discussed and compared with the available experimental information, measured under terrestrial conditions from charge-exchange reactions. Then, the sensitivity of the weak-interaction rates to both astrophysical densities and temperatures is studied. Special attention is paid to the relative contribution to these rates of thermally populated excited states in the decaying nucleus and to the electron captures from the degenerate electron plasma.
Black holes and the weak cosmic censorship
International Nuclear Information System (INIS)
Krolak, A.
A theory of black holes is developed under the assumption of the weak cosmic censorship. It includes Hawking's theory of black holes in the future asymptotically predictable space-times as a special case but it also applies to the cosmological situations including models with nonzero cosmological constant of both signs. (author)
How weak is the subduction zone interface?
Duarte, João C.; Schellart, Wouter P.; Cruden, Alexander R.
Several lines of evidence suggest that subduction zones are weak and that the unique availability of water on Earth is a critical factor in the weakening process. We have evaluated the strength of subduction zone interfaces using two approaches: (i) from empirical relationships between shear stress
Mepham, B.; Kaiser, M.; Thorstensen, E.; Tomkins, S.; Millar, K.
The ethical matrix is a conceptual tool designed to help decision-makers (as individuals or working in groups) reach sound judgements or decisions about the ethical acceptability and/or optimal regulatory controls for existing or prospective technologies in the field of food and agriculture.
Mitjana, Margarida
This book contains the notes of the lectures delivered at an Advanced Course on Combinatorial Matrix Theory held at Centre de Recerca Matemàtica (CRM) in Barcelona. These notes correspond to five series of lectures. The first series is dedicated to the study of several matrix classes defined combinatorially, and was delivered by Richard A. Brualdi. The second one, given by Pauline van den Driessche, is concerned with the study of spectral properties of matrices with a given sign pattern. Dragan Stevanović delivered the third one, devoted to describing the spectral radius of a graph as a tool to provide bounds of parameters related with properties of a graph. The fourth lecture was delivered by Stephen Kirkland and is dedicated to the applications of the Group Inverse of the Laplacian matrix. The last one, given by Ángeles Carmona, focuses on boundary value problems on finite networks with special in-depth on the M-matrix inverse problem.
Visualizing Matrix Multiplication
Daugulis, Peteris; Sondore, Anita
Efficient visualizations of computational algorithms are important tools for students, educators, and researchers. In this article, we point out an innovative visualization technique for matrix multiplication. This method differs from the standard, formal approach by using block matrices to make computations more visual. We find this method a…
DEFF Research Database (Denmark)
Jørnø, Rasmus Leth Vergmann; Gynther, Karsten; Christensen, Ove
useful information, we question whether the axis of time and space comprising the matrix pertains to relevant defining properties of the tools, technology or learning environments to which they are applied. Subsequently we offer an example of an Adobe Connect e-learning session as an illustration...
Acoustic emission as a screening tool for ceramic matrix composites
Ojard, Greg; Goberman, Dan; Holowczak, John
Ceramic matrix composites are composite materials with ceramic fibers in a high temperature matrix of ceramic or glass-ceramic. This emerging class of materials is viewed as enabling for efficiency improvements in many energy conversion systems. The key controlling property of ceramic matrix composites is a relatively weak interface between the matrix and the fiber that aids crack deflection and fiber pullout resulting in greatly increased toughness over monolithic ceramics. United Technologies Research Center has been investigating glass-ceramic composite systems as a tool to understand processing effects on material performance related to the performance of the weak interface. Changes in the interface have been shown to affect the mechanical performance observed in flexural testing and subsequent microstructural investigations have confirmed the performance (or lack thereof) of the interface coating. Recently, the addition of acoustic emission testing during flexural testing has aided the understanding of the characteristics of the interface and its performance. The acoustic emission onset stress changes with strength and toughness and this could be a quality tool in screening the material before further development and use. The results of testing and analysis will be shown and additional material from other ceramic matrix composite systems may be included to show trends.
The finite element response Matrix method
International Nuclear Information System (INIS)
Nakata, H.; Martin, W.R.
A new method for global reactor core calculations is described. This method is based on a unique formulation of the response matrix method, implemented with a higher order finite element method. The unique aspects of this approach are twofold. First, there are two levels to the overall calculational scheme: the local or assembly level and the global or core level. Second, the response matrix scheme, which is formulated at both levels, consists of two separate response matrices rather than one response matrix as is generally the case. These separate response matrices are seen to be quite beneficial for the criticality eigenvalue calculation, because they are independent of k /SUB eff/. The response matrices are generated from a Galerkin finite element solution to the weak form of the diffusion equation, subject to an arbitrary incoming current and an arbitrary distributed source. Calculational results are reported for two test problems, the two-dimensional International Atomic Energy Agency benchmark problem and a two-dimensional pressurized water reactor test problem (Biblis reactor), and they compare well with standard coarse mesh methods with respect to accuracy and efficiency. Moreover, the accuracy (and capability) is comparable to fine mesh for a fraction of the computational cost. Extension of the method to treat heterogeneous assemblies and spatial depletion effects is discussed
Random matrix models for phase diagrams
International Nuclear Information System (INIS)
Vanderheyden, B; Jackson, A D
We describe a random matrix approach that can provide generic and readily soluble mean-field descriptions of the phase diagram for a variety of systems ranging from quantum chromodynamics to high-T c materials. Instead of working from specific models, phase diagrams are constructed by averaging over the ensemble of theories that possesses the relevant symmetries of the problem. Although approximate in nature, this approach has a number of advantages. First, it can be useful in distinguishing generic features from model-dependent details. Second, it can help in understanding the 'minimal' number of symmetry constraints required to reproduce specific phase structures. Third, the robustness of predictions can be checked with respect to variations in the detailed description of the interactions. Finally, near critical points, random matrix models bear strong similarities to Ginsburg-Landau theories with the advantage of additional constraints inherited from the symmetries of the underlying interaction. These constraints can be helpful in ruling out certain topologies in the phase diagram. In this Key Issues Review, we illustrate the basic structure of random matrix models, discuss their strengths and weaknesses, and consider the kinds of system to which they can be applied.
New weak keys in simplified IDEA
Hafman, Sari Agustini; Muhafidzah, Arini
Simplified IDEA (S-IDEA) is simplified version of International Data Encryption Algorithm (IDEA) and useful teaching tool to help students to understand IDEA. In 2012, Muryanto and Hafman have found a weak key class in the S-IDEA by used differential characteristics in one-round (0, ν, 0, ν) → (0,0, ν, ν) on the first round to produce input difference (0,0, ν, ν) on the fifth round. Because Muryanto and Hafman only use three differential characteristics in one-round, we conducted a research to find new differential characteristics in one-round and used it to produce new weak key classes of S-IDEA. To find new differential characteristics in one-round of S-IDEA, we applied a multiplication mod 216+1 on input difference and combination of active sub key Z1, Z4, Z5, Z6. New classes of weak keys are obtained by combining all of these characteristics and use them to construct two new differential characteristics in full-round of S-IDEA with or without the 4th round sub key. In this research, we found six new differential characteristics in one round and combined them to construct two new differential characteristics in full-round of S-IDEA. When two new differential characteristics in full-round of S-IDEA are used and the 4th round sub key required, we obtain 2 new classes of weak keys, 213 and 28. When two new differential characteristics in full-round of S-IDEA are used, yet the 4th round sub key is not required, the weak key class of 213 will be 221 and 28 will be 210. Membership test can not be applied to recover the key bits in those weak key classes. The recovery of those unknown key bits can only be done by using brute force attack. The simulation result indicates that the bit of the key can be recovered by the longest computation time of 0,031 ms.
Compatibility between weak gel and microorganisms in weak gel-assisted microbial enhanced oil recovery.
Qi, Yi-Bin; Zheng, Cheng-Gang; Lv, Cheng-Yuan; Lun, Zeng-Min; Ma, Tao
To investigate weak gel-assisted microbial flooding in Block Wang Long Zhuang in the Jiangsu Oilfield, the compatibility of weak gel and microbe was evaluated using laboratory experiments. Bacillus sp. W5 was isolated from the formation water in Block Wang Long Zhuang. The rate of oil degradation reached 178 mg/day, and the rate of viscosity reduction reached 75.3%. Strain W5 could produce lipopeptide with a yield of 1254 mg/L. Emulsified crude oil was dispersed in the microbial degradation system, and the average diameter of the emulsified oil particles was 18.54 μm. Bacillus sp. W5 did not affect the rheological properties of the weak gel, and the presence of the weak gel did not significantly affect bacterial reproduction (as indicated by an unchanged microbial biomass), emulsification (surface tension is 35.56 mN/m and average oil particles size is 21.38 μm), oil degradation (162 mg/day) and oil viscosity reduction (72.7%). Core-flooding experiments indicated oil recovery of 23.6% when both weak gel and Bacillus sp. W5 were injected into the system, 14.76% when only the weak gel was injected, and 9.78% with strain W5 was injected without the weak gel. The results demonstrate good compatibility between strains W5 and the weak gel and highlight the application potential of weak gel-assisted microbial flooding. Copyright © 2018 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.
pp wave big bangs: Matrix strings and shrinking fuzzy spheres
International Nuclear Information System (INIS)
Das, Sumit R.; Michelson, Jeremy
We find pp wave solutions in string theory with null-like linear dilatons. These provide toy models of big bang cosmologies. We formulate matrix string theory in these backgrounds. Near the big bang 'singularity', the string theory becomes strongly coupled but the Yang-Mills description of the matrix string is weakly coupled. The presence of a second length scale allows us to focus on a specific class of non-Abelian configurations, viz. fuzzy cylinders, for a suitable regime of parameters. We show that, for a class of pp waves, fuzzy cylinders which start out big at early times dynamically shrink into usual strings at sufficiently late times
Possilibity of estimating payoff matrix from model for hit phenomena
International Nuclear Information System (INIS)
Ishii, Akira; Sakaidani, Shota; Iwanaga, Saori
The conflicts of topics on social media is considered using an extended mathematical model based on the mathematical model for hit phenomena that has been used to analyze entertainment hits. The social media platform used in this study was blog. The calculation results shows examples of strong conflict, weak conflict, and no conflict cases. Since the conflict of two topics can be considered in the framework of game theory, the results can be used to determine each matrix element of the payoff matrix of game theory.
Detection and identification of concealed weapons using matrix pencil
Adve, Raviraj S.; Thayaparan, Thayananthan
The detection and identification of concealed weapons is an extremely hard problem due to the weak signature of the target buried within the much stronger signal from the human body. This paper furthers the automatic detection and identification of concealed weapons by proposing the use of an effective approach to obtain the resonant frequencies in a measurement. The technique, based on Matrix Pencil, a scheme for model based parameter estimation also provides amplitude information, hence providing a level of confidence in the results. Of specific interest is the fact that Matrix Pencil is based on a singular value decomposition, making the scheme robust against noise.
Rank-Optimized Logistic Matrix Regression toward Improved Matrix Data Classification.
Zhang, Jianguang; Jiang, Jianmin
While existing logistic regression suffers from overfitting and often fails in considering structural information, we propose a novel matrix-based logistic regression to overcome the weakness. In the proposed method, 2D matrices are directly used to learn two groups of parameter vectors along each dimension without vectorization, which allows the proposed method to fully exploit the underlying structural information embedded inside the 2D matrices. Further, we add a joint [Formula: see text]-norm on two parameter matrices, which are organized by aligning each group of parameter vectors in columns. This added co-regularization term has two roles-enhancing the effect of regularization and optimizing the rank during the learning process. With our proposed fast iterative solution, we carried out extensive experiments. The results show that in comparison to both the traditional tensor-based methods and the vector-based regression methods, our proposed solution achieves better performance for matrix data classifications.
Weak mixing below the weak scale in dark-matter direct detection
Brod, Joachim; Grinstein, Benjamin; Stamou, Emmanuel; Zupan, Jure
If dark matter couples predominantly to the axial-vector currents with heavy quarks, the leading contribution to dark-matter scattering on nuclei is either due to one-loop weak corrections or due to the heavy-quark axial charges of the nucleons. We calculate the effects of Higgs and weak gauge-boson exchanges for dark matter coupling to heavy-quark axial-vector currents in an effective theory below the weak scale. By explicit computation, we show that the leading-logarithmic QCD corrections are important, and thus resum them to all orders using the renormalization group.
Dark-Matter Particles without Weak-Scale Masses or Weak Interactions
International Nuclear Information System (INIS)
Feng, Jonathan L.; Kumar, Jason
We propose that dark matter is composed of particles that naturally have the correct thermal relic density, but have neither weak-scale masses nor weak interactions. These models emerge naturally from gauge-mediated supersymmetry breaking, where they elegantly solve the dark-matter problem. The framework accommodates single or multiple component dark matter, dark-matter masses from 10 MeV to 10 TeV, and interaction strengths from gravitational to strong. These candidates enhance many direct and indirect signals relative to weakly interacting massive particles and have qualitatively new implications for dark-matter searches and cosmological implications for colliders
Asymptotic theory of weakly dependent random processes
Rio, Emmanuel
Presenting tools to aid understanding of asymptotic theory and weakly dependent processes, this book is devoted to inequalities and limit theorems for sequences of random variables that are strongly mixing in the sense of Rosenblatt, or absolutely regular. The first chapter introduces covariance inequalities under strong mixing or absolute regularity. These covariance inequalities are applied in Chapters 2, 3 and 4 to moment inequalities, rates of convergence in the strong law, and central limit theorems. Chapter 5 concerns coupling. In Chapter 6 new deviation inequalities and new moment inequalities for partial sums via the coupling lemmas of Chapter 5 are derived and applied to the bounded law of the iterated logarithm. Chapters 7 and 8 deal with the theory of empirical processes under weak dependence. Lastly, Chapter 9 describes links between ergodicity, return times and rates of mixing in the case of irreducible Markov chains. Each chapter ends with a set of exercises. The book is an updated and extended ...
Nulling tomography with weak gravitational lensing
International Nuclear Information System (INIS)
Huterer, Dragan; White, Martin
We explore several strategies of eliminating (or nulling) the small-scale information in weak lensing convergence power spectrum measurements in order to protect against undesirable effects, for example, the effects of baryonic cooling and pressure forces on the distribution of large-scale structures. We selectively throw out the small-scale information in the convergence power spectrum that is most sensitive to the unwanted bias, while trying to retain most of the sensitivity to cosmological parameters. The strategies are effective in the difficult but realistic situations when we are able to guess the form of the contaminating effect only approximately. However, we also find that the simplest scheme of simply not using information from the largest multipoles works about as well as the proposed techniques in most, although not all, realistic cases. We advocate further exploration of nulling techniques and believe that they will find important applications in the weak lensing data mining
A dynamical weak scale from inflation
Energy Technology Data Exchange (ETDEWEB)
You, Tevong, E-mail: firstname.lastname@example.com [DAMTP, University of Cambridge, Wilberforce Road, Cambridge, CB3 0WA (United Kingdom)
Dynamical scanning of the Higgs mass by an axion-like particle during inflation may provide a cosmological component to explaining part of the hierarchy problem. We propose a novel interplay of this cosmological relaxation mechanism with inflation, whereby the backreaction of the Higgs vacuum expectation value near the weak scale causes inflation to end. As Hubble drops, the relaxion's dissipative friction increases relative to Hubble and slows it down enough to be trapped by the barriers of its periodic potential. Such a scenario raises the natural cut-off of the theory up to ∼ 10{sup 10} GeV, while maintaining a minimal relaxion sector without having to introduce additional scanning scalars or new physics coincidentally close to the weak scale.
Weak-light phase locking for LISA
International Nuclear Information System (INIS)
McNamara, Paul W
The long armlengths of the LISA interferometer, and the finite aperture of the telescope, lead to an optical power attenuation of ∼10 -10 of the transmitted to received light. Simple reflection at the end of the arm is therefore not an optimum interferometric design. Instead, a local laser is offset phase locked to the weak incoming beam, transferring the phase information of the incoming to the outgoing light. This paper reports on an experiment to characterize a weak-light phase-locking scheme suitable for LISA in which a diode-pumped, Nd:YAG, non-planar ring oscillator (NPRO) is offset phase locked to a low-power (13 pW) frequency stabilized master NPRO. Preliminary results of the relative phase noise of the slave laser shows shot noise limited performance above 0.4 Hz. Excess noise is observed at lower frequencies, most probably due to thermal effects in the optical arrangement and phase-sensing electronics
Towards weakly constrained double field theory
Directory of Open Access Journals (Sweden)
Kanghoon Lee
Full Text Available We show that it is possible to construct a well-defined effective field theory incorporating string winding modes without using strong constraint in double field theory. We show that X-ray (Radon transform on a torus is well-suited for describing weakly constrained double fields, and any weakly constrained fields are represented as a sum of strongly constrained fields. Using inverse X-ray transform we define a novel binary operation which is compatible with the level matching constraint. Based on this formalism, we construct a consistent gauge transform and gauge invariant action without using strong constraint. We then discuss the relation of our result to the closed string field theory. Our construction suggests that there exists an effective field theory description for massless sector of closed string field theory on a torus in an associative truncation.
Quantum Groups, Property (T), and Weak Mixing
Brannan, Michael; Kerr, David
For second countable discrete quantum groups, and more generally second countable locally compact quantum groups with trivial scaling group, we show that property (T) is equivalent to every weakly mixing unitary representation not having almost invariant vectors. This is a generalization of a theorem of Bekka and Valette from the group setting and was previously established in the case of low dual by Daws, Skalski, and Viselter. Our approach uses spectral techniques and is completely different from those of Bekka-Valette and Daws-Skalski-Viselter. By a separate argument we furthermore extend the result to second countable nonunimodular locally compact quantum groups, which are shown in particular not to have property (T), generalizing a theorem of Fima from the discrete setting. We also obtain quantum group versions of characterizations of property (T) of Kerr and Pichot in terms of the Baire category theory of weak mixing representations and of Connes and Weiss in terms of the prevalence of strongly ergodic actions.
Orbits in weak and strong bars
Contopoulos, George
The authors study the plane orbits in simple bar models embedded in an axisymmetric background when the bar density is about 1% (weak), 10% (intermediate) or 100% (strong bar) of the axisymmetric density. Most orbits follow the stable periodic orbits. The basic families of periodic orbits are described. In weak bars with two Inner Lindblad Resonances there is a family of stable orbits extending from the center up to the Outer Lindblad Resonance. This family contains the long period orbits near corotation. Other stable families appear between the Inner Lindblad Resonances, outside the Outer Lindblad Resonance, around corotation (short period orbits) and around the center (retrograde). Some families become unstable or disappear in strong bars. A comparison is made with cases having one or no Inner Lindblad Resonance. (12 refs).
Weakly Collisional and Collisionless Astrophysical Plasmas
DEFF Research Database (Denmark)
Berlok, Thomas
are used to study weakly collisional, stratified atmospheres which offer a useful model of the intracluster medium of galaxy clusters. Using linear theory and computer simulations, we study instabilities that feed off thermal and compositional gradients. We find that these instabilities lead to vigorous...... investigate helium mixing in the weakly collisional intracluster medium of galaxy clusters using Braginskii MHD. Secondly, we present a newly developed Vlasov-fluid code which can be used for studying fully collisionless plasmas such as the solar wind and hot accretions flows. The equations of Braginskii MHD...... associated with the ions and is thus well suited for studying collisionless plasmas. We have developed a new 2D-3V Vlasov-fluid code which works by evolving the phase-space density distribution of the ions while treating the electrons as an inertialess fluid. The code uses the particle-incell (PIC) method...
Weak mixing angle measurements at hadron colliders
Di Simone, Andrea; The ATLAS collaboration
The Talk will cover weak mixing angle measurements at hadron colliders ATLAS and CMS in particular. ATLAS has measured the forward-backward asymmetry for the neutral current Drell Yan process in a wide mass range around the Z resonance region using dielectron and dimuon final states with $\\sqrt{s}$ =7 TeV data. For the dielectron channel, the measurement includes electrons detected in the forward calorimeter which extends the covered phase space. The result is then used to extract a measurement of the effective weak mixing angle. Uncertainties from the limited knowledge on the parton distribution functions in the proton constitute a significant part of the uncertainty and a dedicated study is performed to obtain a PDF set describing W and Z data measured previously by ATLAS. Similar studies from CMS will be reported.
Bound states in weakly disordered spin ladders
Energy Technology Data Exchange (ETDEWEB)
Arlego, M. [Departamento de Fisica, Universidad Nacional de La Plata, CC 67 (1900) La Plata (Argentina)]. E-mail: firstname.lastname@example.com; Brenig, W. [Institut fuer Theoretische Physik, Technische Universitaet Braunschweig (Germany); Cabra, D.C. [Laboratoire de Physique Theorique, Universite Louis Pasteur Strasbourg (France); Heidrich-Meisner, F. [Institut fuer Theoretische Physik, Technische Universitaet Braunschweig (Germany); Honecker, A. [Institut fuer Theoretische Physik, Technische Universitaet Braunschweig (Germany); Rossini, G. [Departamento de Fisica, Universidad Nacional de La Plata, CC 67 (1900) La Plata (Argentina)
We study the appearance of bound states in the spin gap of spin-12 ladders induced by weak bond disorder. Starting from the strong-coupling limit, i.e., the limit of weakly coupled dimers, we perform a projection on the single-triplet subspace and derive the position of bound states for the single impurity problem of one modified coupling as well as for small impurity clusters. The case of a finite concentration of impurities is treated with the coherent-potential approximation (CPA) in the strong-coupling limit and compared with numerical results. Further, we analyze the details in the structure of the density of states and relate their origin to the influence of impurity clusters.
Weak cosmic censorship: as strong as ever.
Hod, Shahar
Spacetime singularities that arise in gravitational collapse are always hidden inside of black holes. This is the essence of the weak cosmic censorship conjecture. The hypothesis, put forward by Penrose 40 years ago, is still one of the most important open questions in general relativity. In this Letter, we reanalyze extreme situations which have been considered as counterexamples to the weak cosmic censorship conjecture. In particular, we consider the absorption of scalar particles with large angular momentum by a black hole. Ignoring back reaction effects may lead one to conclude that the incident wave may overspin the black hole, thereby exposing its inner singularity to distant observers. However, we show that when back reaction effects are properly taken into account, the stability of the black-hole event horizon is irrefutable. We therefore conclude that cosmic censorship is actually respected in this type of gedanken experiments.
Shock Wave Dynamics in Weakly Ionized Plasmas
Johnson, Joseph A., III
An investigation of the dynamics of shock waves in weakly ionized argon plasmas has been performed using a pressure ruptured shock tube. The velocity of the shock is observed to increase when the shock traverses the plasma. The observed increases cannot be accounted for by thermal effects alone. Possible mechanisms that could explain the anomalous behavior include a vibrational/translational relaxation in the nonequilibrium plasma, electron diffusion across the shock front resulting from high electron mobility, and the propagation of ion-acoustic waves generated at the shock front. Using a turbulence model based on reduced kinetic theory, analysis of the observed results suggest a role for turbulence in anomalous shock dynamics in weakly ionized media and plasma-induced hypersonic drag reduction.
Qian, Weixian; Zhou, Xiaojun; Lu, Yingcheng; Xu, Jiang
Both the Jones and Mueller matrices encounter difficulties when physically modeling mixed materials or rough surfaces due to the complexity of light-matter interactions. To address these issues, we derived a matrix called the paths correlation matrix (PCM), which is a probabilistic mixture of Jones matrices of every light propagation path. Because PCM is related to actual light propagation paths, it is well suited for physical modeling. Experiments were performed, and the reflection PCM of a mixture of polypropylene and graphite was measured. The PCM of the mixed sample was accurately decomposed into pure polypropylene's single reflection, pure graphite's single reflection, and depolarization caused by multiple reflections, which is consistent with the theoretical derivation. Reflection parameters of rough surface can be calculated from PCM decomposition, and the results fit well with the theoretical calculations provided by the Fresnel equations. These theoretical and experimental analyses verify that PCM is an efficient way to physically model light-matter interactions.
International Nuclear Information System (INIS)
Sasakawa, T.; Okuno, H.; Ishikawa, S.; Sawada, T.
The off-shell t matrix is expressed as a sum of one nonseparable and one separable terms so that it is useful for applications to more-than-two body problems. All poles are involved in this one separable term. Both the nonseparable and the separable terms of the kernel G 0 t are regular at the origin. The nonseparable term of this kernel vanishes at large distances, while the separable term behaves asymptotically as the spherical Hankel function. These properties make our expression free from defects inherent in the Jost or the K-matrix expressions, and many applications are anticipated. As the application, a compact expression of the many-level formula is presented. Also the application is suggested to the breakup threebody problem based on the Faddeev equation. It is demonstrated that the breakup amplitude is expressed in a simple and physically interesting form and we can calculate it in coordinate space
SANS observations on weakly flocculated dispersions
DEFF Research Database (Denmark)
Mischenko, N.; Ourieva, G.; Mortensen, K.
Structural changes occurring in colloidal dispersions of poly-(methyl metacrylate) (PMMA) particles, sterically stabilized with poly-(12-hydroxystearic acid) (PHSA), while varying the solvent quality, temperature and shear rate, are investigated by small-angle neutron scattering (SANS......). For a moderately concentrated dispersion in a marginal solvent the transition on cooling from the effective stability to a weak attraction is monitored, The degree of attraction is determined in the framework of the sticky spheres model (SSM), SANS and rheological results are correlated....
The weak conversion rate in quark matter
International Nuclear Information System (INIS)
Heiselberg, H.
The weak conversion rate of strange to down quarks, s + u ↔ u + d, is calculated analytically for degenerate u, d and s quark matter to leading orders in temperature and deviations from chemical equilibrium. The rate is applied to burning of neutron matter into quark matter, to evaporation from quark nuggets in the early universe, for estimating the lifetime of strangelets, and to pulsar glitches
BCS superconductivity for weakly coupled clusters
International Nuclear Information System (INIS)
Friedel, J.
BCS superconductivity is expected to have fairly high critical temperatures when clusters of moderate sizes are weakly coupled to form a crystal. This remark extends to quasi zerodimensional cases, a remark initially made by Labbe for quasi one-dimensional ones and by Hirsch, Bok and Labbe for quasi twodimensional ones. Possible applications are envisaged for twodimensional clusters (fullerene) or threedimensional ones (metal clusters, Chevrel phases). Conditions for optimal applicability of the scheme are somewhat restricted. (orig.)
Deep inelastic inclusive weak and electromagnetic interactions
International Nuclear Information System (INIS)
Adler, S.L.
The theory of deep inelastic inclusive interactions is reviewed, emphasizing applications to electromagnetic and weak charged current processes. The following reactions are considered: e + N → e + X, ν + N → μ - + X, anti ν + N → μ + + X where X denotes a summation over all final state hadrons and the ν's are muon neutrinos. After a discussion of scaling, the quark-parton model is invoked to explain the principle experimental features of deep inelastic inclusive reactions
Weakly interacting massive particles and stellar structure
International Nuclear Information System (INIS)
Bouquet, A.
The existence of weakly interacting massive particles (WIMPs) may solve both the dark matter problem and the solar neutrino problem. Such particles affect the energy transport in the stellar cores and change the stellar structure. We present the results of an analytic approximation to compute these effects in a self-consistent way. These results can be applied to many different stars, but we focus on the decrease of the 8 B neutrino flux in the case of the Sun
Search for weakly decaying b -flavored pentaquarks
Aaij, R.; Adeva, B.; Ajaltouni, Z.; Akar, S.; Alessio, F.; Alexander, M.; Alfonso Albero, A.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Andreassi, G.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Archilli, F.; D'Argent, P.; Arnau Romeu, J.; Artamonov, A.; Artuso, M.; Aslanides, E.; Atzeni, M.; Auriemma, G.; Baalouch, M.; Babuschkin, I.; Bachmann, S.; BacK, J. J.; Badalov, A.; Baesso, C.; Baker, S.; Balagura, V.; Baldini, W.; Baranov, A.; Barlow, R. J.; Barschel, C.; BarsuK, S.; Barter, W.; Baryshnikov, F.; Batozskaya, V.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Beiter, A.; Bel, L. J.; Beliy, N.; Bellee, V.; Belloli, N.; Belous, K.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; BeraneK, S.; Berezhnoy, A.; Bernet, R.; Berninghoff, D.; Bertholet, E.; Bertolin, A.; Betancourt, C.; Betti, F.; Bettler, M. O.; Van Beuzekom, M.; Bezshyiko, Ia; Bifani, S.; Billoir, P.; Birnkraut, A.; Bizzeti, A.; Bjørn, M.; Blake, T.; Blanc, F.; BlusK, S.; Bocci, V.; Boettcher, T.; Bondar, A.; Bondar, N.; Bordyuzhin, I.; Borghi, S.; BorisyaK, M.; Borsato, M.; Bossu, F.; Boubdir, M.; BowcocK, T. J.V.; Bowen, E.; Bozzi, C.; Brodzicka, J.; Brundu, D.; Buchanan, E.; Burr, C.; Bursche, A.; Buytaert, J.; Byczynski, W.; Cadeddu, S.; Cai, H.; Calabrese, R.; Calladine, R.; Calvi, M.; Calvo Gomez, M.; Camboni, A.; Campana, P.; Campora Perez, D. H.; Capriotti, L.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carniti, P.; Carvalho Akiba, K.; Casse, G.; Cassina, L.; Cattaneo, M.; Cavallero, G.; Cenci, R.; Chamont, D.; Chapman, M. G.; Charles, M.; Charpentier, Ph; Chatzikonstantinidis, G.; Chefdeville, M.; Cheung, S. F.; Chitic, S. G.; Chobanova, V.; Chrzaszcz, M.; Chubykin, A.; Ciambrone, P.; Cid Vidal, X.; CiezareK, G.; Clarke, P. E.L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coco, V.; Cogan, J.; Cogneras, E.; Cogoni, V.; Cojocariu, L.; Collins, P.; Colombo, T.; Comerma-Montells, A.; Contu, A.; Coombs, G.; Coquereau, S.; Corti, G.; Corvo, M.; Costa Sobral, C. M.; Couturier, B.; Cowan, G. A.; CraiK, D. C.; Crocombe, A.; Cruz Torres, M.; Currie, R.; D'Ambrosio, C.; Da Cunha Marinho, F.; Da Silva, C. L.; Dall'Occo, E.; Dalseno, J.; Davis, A.; De Aguiar Francisco, O.; De Bruyn, K.; De Capua, S.; De Cian, M.; De Miranda, J. M.; De Paula, L.; De Serio, M.; De Simone, P.; Dean, C. T.; Decamp, D.; Del Buono, L.; Dembinski, H. P.; Demmer, M.; DendeK, A.; Derkach, D.; Deschamps, O.; Dettori, F.; Dey, B.; Di Canto, A.; Di Nezza, P.; Dordei, F.; Dorigo, M.; Dosil Suárez, A.; Douglas, L.; Dovbnya, A.; Dreimanis, K.; Dujany, G.; Durante, P.; Durham, J. M.; Dutta, D.; Dzhelyadin, R.; Dziewiecki, M.; Dziurda, A.; Dzyuba, A.; Easo, S.; Ebert, M.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; Ely, S.; Esen, S.; Evans, H. M.; Evans, T.; Falabella, A.; Farley, N.; Farry, S.; Fazzini, D.; Federici, L.; Ferguson, D.; Fernandez, G.; Fernandez Declara, P.; Fernandez Prieto, A.; Ferrari, F.; Ferreira Lopes, L.; Ferreira Rodrigues, F.; Ferro-Luzzi, M.; Filippov, S.; Fini, R. A.; Fiorini, M.; Firlej, M.; FitzpatricK, C.; Fiutowski, T.; Fleuret, F.; Fontana, M.; Fontanelli, F.; Forty, R.; Franco Lima, V.; FranK, M.; Frei, C.; Fu, J.; FunK, W.; Furfaro, E.; Färber, C.; Gabriel, E.; Gallas Torreira, A.; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; Garcia Martin, L. M.; García Pardiñas, J.; Garra Tico, J.; Garrido, L.; Gascon, D.; Gaspar, C.; Gavardi, L.; Gazzoni, G.; GericK, D.; GersabecK, E.; GersabecK, M.; Gershon, T.; Ghez, Ph; Gianì, S.; Gibson, V.; Girard, O. G.; Giubega, L.; Gizdov, K.; Gligorov, V. V.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gorelov, I. V.; Gotti, C.; Govorkova, E.; Grabowski, J. P.; Graciani Diaz, R.; Granado Cardoso, L. A.; Graugés, E.; Graverini, E.; Graziani, G.; Grecu, A.; Greim, R.; Grillo, L.; Gruber, L.; Gruberg Cazon, B. R.; Grünberg, O.; Gushchin, E.; Guz, Yu; Gys, T.; Göbel, C.; Hadavizadeh, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hamilton, B.; Han, X.; HancocK, T. H.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Hasse, C.; Hatch, M.; Hecker, M.; Heinicke, K.; Heister, A.; Hennessy, K.; Henrard, P.; Van Herwijnen, E.; Heß, M.; Hicheur, A.; Hill, D.; Hopchev, P. H.; Huard, Z. C.; Hulsbergen, W.; Humair, T.; Hushchyn, M.; Hutchcroft, D.; Ibis, P.; IdziK, M.; Ilten, P.; Jacobsson, R.; Jalocha, J.; Jans, E.; Jawahery, A.; John, M.; Jones, C. R.; Joram, C.; Jost, B.; JuriK, N.; Kandybei, S.; Karacson, M.; Kariuki, J. M.; Karodia, S.; Kazeev, N.; Kecke, M.; Keizer, F.; Kelsey, M.; Kenzie, M.; Ketel, T.; Khairullin, E.; Khanji, B.; Khurewathanakul, C.; Kirn, T.; Klaver, S.; Klimaszewski, K.; Klimkovich, T.; Koliiev, S.; Kolpin, M.; Kopecna, R.; Koppenburg, P.; Kosmyntseva, A.; Kotriakhova, S.; Kozeiha, M.; KravchuK, L.; Kreps, M.; Kress, F.; Krokovny, P.; Krzemien, W.; Kucewicz, W.; KucharczyK, M.; Kudryavtsev, V.; Kuonen, A. K.; Kvaratskheliya, T.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lanfranchi, G.; Langenbruch, C.; Latham, T.; Lazzeroni, C.; Le Gac, R.; Leflat, A.; Lefrançois, J.; Lefèvre, R.; Lemaitre, F.; Lemos Cid, E.; Leroy, O.; LesiaK, T.; Leverington, B.; Liang, X.; Likhomanenko, T.; Lindner, R.; Lionetto, F.; Lisovskyi, V.; Loh, D.; Loi, A.; Longstaff, I.; Lopes, J. H.; Lucchesi, D.; Lucio Martinez, M.; Luo, H.; Lupato, A.; Luppi, E.; Lupton, O.; Lusiani, A.; Lyu, X.; Machefert, F.; Maciuc, F.; Macko, V.; MackowiaK, P.; Maddrell-Mander, S.; Maev, O.; Maguire, K.; Maisuzenko, D.; Majewski, M. W.; Malde, S.; Malecki, B.; Malinin, A.; Maltsev, T.; Manca, G.; Mancinelli, G.; Marangotto, D.; Maratas, J.; Marchand, J. F.; Marconi, U.; Marin Benito, C.; Marinangeli, M.; Marino, P.; Marks, J.; Martellotti, G.; Martin, M.; Martinelli, M.; Martinez Santos, D.; Martinez Vidal, F.; Massafferri, A.; Matev, R.; Mathad, A.; Mathe, Z.; Matteuzzi, C.; Mauri, A.; Maurice, E.; Maurin, B.; Mazurov, A.; McCann, M.; McNab, A.; McNulty, R.; Mead, J. V.; Meadows, B.; Meaux, C.; Meier, F.; Meinert, N.; MelnychuK, D.; MerK, M.; Merli, A.; Michielin, E.; Milanes, D. A.; Millard, E.; Minard, M. N.; Minzoni, L.; Mitzel, D. S.; Mogini, A.; Molina Rodriguez, J.; Mombächer, T.; Monroy, I. A.; Monteil, S.; Morandin, M.; Morello, M. J.; Morgunova, O.; Moron, J.; Morris, A. B.; Mountain, R.; Muheim, F.; Müller, D.; Müller, K.; Müller, V.; NaiK, P.; Nakada, T.; Nandakumar, R.; Nandi, A.; Nasteva, I.; Needham, M.; Neri, N.; Neubert, S.; Neufeld, N.; Neuner, M.; Nguyen-Mau, C.; Nieswand, S.; Niet, R.; Nikitin, N.; Nikodem, T.; Nogay, A.; O'Hanlon, D. P.; Oblakowska-Mucha, A.; Obraztsov, V.; Ogilvy, S.; Oldeman, R.; Onderwater, C. J.G.; Ossowska, A.; Otalora Goicochea, J. M.; Owen, P.; Oyanguren, A.; Pais, P. R.; Palano, A.; Palutan, M.; Papanestis, A.; Pappagallo, M.; Pappalardo, L. L.; Parker, W.; Parkes, C.; Passaleva, G.; Pastore, A.; Patel, M.; Patrignani, C.; Pellegrino, A.; Penso, G.; Pepe Altarelli, M.; Perazzini, S.; Pereima, D.; Perret, P.; Pescatore, L.; Petridis, K.; Petrolini, A.; Petrov, A.; Petruzzo, M.; Picatoste Olloqui, E.; PietrzyK, B.; PietrzyK, G.; Pikies, M.; Pinci, D.; Pisani, F.; Pistone, A.; Piucci, A.; Placinta, V.; Playfer, S.; Plo Casasus, M.; Polci, F.; Poli Lener, M.; Poluektov, A.; Polyakov, I.; Polycarpo, E.; Pomery, G. J.; Ponce, S.; Popov, A.; Popov, D.; Poslavskii, S.; Potterat, C.; Price, E.; Prisciandaro, J.; Prouve, C.; Pugatch, V.; Puig Navarro, A.; Pullen, H.; Punzi, G.; Qian, W.; Qin, J.; Quagliani, R.; Quintana, B.; Rachwal, B.; Rademacker, J. H.; Rama, M.; Ramos Pernas, M.; Rangel, M. S.; RaniuK, I.; Ratnikov, F.; Raven, G.; Ravonel Salzgeber, M.; Reboud, M.; Redi, F.; Reichert, S.; Dos Reis, A. C.; Remon Alepuz, C.; Renaudin, V.; Ricciardi, S.; Richards, S.; Rihl, M.; Rinnert, K.; Robbe, P.; Robert, A.; Rodrigues, A. B.; Rodrigues, E.; Rodriguez Lopez, J. A.; Rogozhnikov, A.; Roiser, S.; Rollings, A.; Romanovskiy, V.; Romero Vidal, A.; Rotondo, M.; Rudolph, M. S.; Ruf, T.; Ruiz Valls, P.; Ruiz Vidal, J.; Saborido Silva, J. J.; Sadykhov, E.; Sagidova, N.; Saitta, B.; Salustino Guimaraes, V.; Sanchez Mayordomo, C.; Sanmartin Sedes, B.; Santacesaria, R.; Santamarina Rios, C.; Santimaria, M.; Santovetti, E.; Sarpis, G.; Satriano, C.; Satta, A.; Saunders, D. M.; Savrina, D.; Schael, S.; Schellenberg, M.; Schiller, M.; Schindler, H.; Schmelling, M.; Schmelzer, T.; Schmidt, B.; Schneider, O.; Schopper, A.; Schreiner, H. F.; Schubiger, M.; Schune, M. H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Semennikov, A.; Sepulveda, E. S.; Sergi, A.; Serra, N.; Serrano, J.; Sestini, L.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Shevchenko, V.; Siddi, B. G.; Silva Coutinho, R.; Silva De Oliveira, L.; Simi, G.; Simone, S.; Sirendi, M.; Skidmore, N.; Skwarnicki, T.; Smith, J.; Smith, M.; Soares Lavra, L.; Sokoloff, M. D.; Soler, F. J.P.; Souza De Paula, B.; Spaan, B.; Spradlin, P.; Sridharan, S.; Stagni, F.; Stahl, M.; Stahl, S.; Stefko, P.; Stefkova, S.; Steinkamp, O.; Stemmle, S.; Stenyakin, O.; Stepanova, M.; Stevens, H.; Stone, S.; Storaci, B.; Stracka, S.; Stramaglia, M. E.; Straticiuc, M.; Straumann, U.; Sun, J.; Sun, L.; SwienteK, K.; Syropoulos, V.; SzumlaK, T.; Szymanski, M.; T'Jampens, S.; Tayduganov, A.; Tekampe, T.; Tellarini, G.; Teubert, F.; Van Tilburg, J.; Tilley, M. J.; Tisserand, V.; Tobin, M.; TolK, S.; Tomassetti, L.; Tonelli, D.; Tourinho Jadallah Aoude, R.; Tournefier, E.; Traill, M.; Tran, M. T.; Tresch, M.; Trisovic, A.; Tsaregorodtsev, A.; Tsopelas, P.; Tully, A.; Tuning, N.; Ukleja, A.; Usachov, A.; Ustyuzhanin, A.; Uwer, U.; Vacca, C.; Vagner, A.; Vagnoni, V.; Valassi, A.; Valat, S.; Valenti, G.; Vazquez Gomez, R.; Vazquez Regueiro, P.; Vecchi, S.; Van Veghel, M.; Velthuis, J. J.; Veltri, M.; Veneziano, G.; Venkateswaran, A.; Verlage, T. A.; Vernet, M.; Vesterinen, M.; Viana Barbosa, J. V.; Vieira, D.; Vieites Diaz, M.; Viemann, H.; Vilasis-Cardona, X.; Vitti, M.; Volkov, V.; Vollhardt, A.; Voneki, B.; Vorobyev, A.; Vorobyev, V.; Voß, C.; Vázquez Sierra, C.; Waldi, R.; Walsh, J.; Ward, D. R.; WarK, H. M.; Watson, N. K.; Websdale, D.; Weiden, A.; Weisser, C.; Whitehead, M.; Wicht, J.; Wilkinson, G.; Wilkinson, M.; Williams, M.; Williams, M.; Wilson, F. F.; Wimberley, J.; Winn, M.; Wishahi, J.; Wislicki, W.; WiteK, M.; Wormser, G.; Wotton, S. A.; Wyllie, K.; Xie, Y.; Xu, M.; Xu, Q.; Yang, Z.; Yang, Z.; Yao, Y.; Yin, H.; Yuan, X.; Yushchenko, O.; Zarebski, K. A.; Zavertyaev, M.; Zhelezov, A.; Zhukov, V.; Zonneveld, J. B.; Zucchelli, S.
Investigations of the existence of pentaquark states containing a single b (anti)quark decaying weakly into four specific final states J/ψK+π-p, J/ψK-π-p, J/ψK-π+p, and J/ψφ(1020)p are reported. The data sample corresponds to an integrated luminosity of 3.0 fb-1 in 7 and 8 TeV pp collisions acquired
Acute neuromuscular weakness associated with dengue infection
Directory of Open Access Journals (Sweden)
Harmanjit Singh Hira
Full Text Available Background: Dengue infections may present with neurological complications. Whether these are due to neuromuscular disease or electrolyte imbalance is unclear. Materials and Methods: Eighty-eight patients of dengue fever required hospitalization during epidemic in year 2010. Twelve of them presented with acute neuromuscular weakness. We enrolled them for study. Diagnosis of dengue infection based on clinical profile of patients, positive serum IgM ELISA, NS1 antigen, and sero-typing. Complete hemogram, kidney and liver functions, serum electrolytes, and creatine phosphokinase (CPK were tested. In addition, two patients underwent nerve conduction velocity (NCV test and electromyography. Results: Twelve patients were included in the present study. Their age was between 18 and 34 years. Fever, myalgia, and motor weakness of limbs were most common presenting symptoms. Motor weakness developed on 2 nd to 4 th day of illness in 11 of 12 patients. In one patient, it developed on 10 th day of illness. Ten of 12 showed hypokalemia. One was of Guillain-Barré syndrome and other suffered from myositis; they underwent NCV and electromyography. Serum CPK and SGOT raised in 8 out of 12 patients. CPK of patient of myositis was 5098 IU. All of 12 patients had thrombocytopenia. WBC was in normal range. Dengue virus was isolated in three patients, and it was of serotype 1. CSF was normal in all. Within 24 hours, those with hypokalemia recovered by potassium correction. Conclusions: It was concluded that the dengue virus infection led to acute neuromuscular weakness because of hypokalemia, myositis, and Guillain-Barré syndrome. It was suggested to look for presence of hypokalemia in such patients.
International Nuclear Information System (INIS)
Raju Viswanathan, R.
We study examples of one dimensional matrix models whose potentials possess an energy spectrum that can be explicitly determined. This allows for an exact solution in the continuum limit. Specifically, step-like potentials and the Morse potential are considered. The step-like potentials show no scaling behaviour and the Morse potential (which corresponds to a γ = -1 model) has the interesting feature that there are no quantum corrections to the scaling behaviour in the continuum limit. (author). 5 refs
Brenner, Barbara; Schlegelmilch, Bodo B.; Ambos, Björn
This case describes how Nike, a consumer goods company with an ever expanding portfolio and a tremendous brand value, manages the tradeoff between local responsiveness and global integration. In particular, the case highlights Nike's organizational structure that consists of a global matrix organization that is replicated at a regional level for the European market. While this organizational structure allows Nike to respond to local consumer tastes it also ensures that the company benefits f...
Wilkinson, Michael; Grant, John
We consider a stochastic process in which independent identically distributed random matrices are multiplied and where the Lyapunov exponent of the product is positive. We continue multiplying the random matrices as long as the norm, ɛ, of the product is less than unity. If the norm is greater than unity we reset the matrix to a multiple of the identity and then continue the multiplication. We address the problem of determining the probability density function of the norm, \
Dijkgraaf, R; Verlinde, Herman L
Via compactification on a circle, the matrix model of M-theory proposed by Banks et al suggests a concrete identification between the large N limit of two-dimensional N=8 supersymmetric Yang-Mills theory and type IIA string theory. In this paper we collect evidence that supports this identification. We explicitly identify the perturbative string states and their interactions, and describe the appearance of D-particle and D-membrane states.
Weak interaction studies from nuclear beta decay
International Nuclear Information System (INIS)
Morita, M.
The studies performed at the theoretical nuclear physics division of the Laboratory of Nuclear Studies, Osaka University, are reported. Electron spin density and internal conversion process, nuclear excitation by electron transition, beta decay, weak charged current, and beta-ray angular distributions in oriented nuclei have been studied. The relative intensity of internal conversion electrons for the case in which the radial wave functions of orbital electrons are different for electron spin up and down was calculated. The calculated value was in good agreement with the experimental one. The nuclear excitation following the transition of orbital electrons was studied. The calculated probability of the nuclear excitation of Os 189 was 1.4 x 10 - 7 in conformity with the experimental value 1.7 x 10 - 7 . The second class current and other problems on beta-decay have been extensively studied, and described elsewhere. Concerning weak charged current, the effects of all induced terms, the time component of main axial vector, all partial waves of leptons, Coulomb correction for the electrons in finite size nuclei, and radiative correction were studied. The beta-ray angular distribution for the 1 + -- 0 + transition in oriented B 12 and N 12 was investigated. In this connection, investigation on the weak magnetism to include all higher order corrections for the evaluation of the spectral shape factors was performed. Other works carried out by the author and his collaborators are also explained. (Kato, T.)
Skeletal muscle weakness in osteogenesis imperfecta mice.
Gentry, Bettina A; Ferreira, J Andries; McCambridge, Amanda J; Brown, Marybeth; Phillips, Charlotte L
Exercise intolerance, muscle fatigue and weakness are often-reported, little-investigated concerns of patients with osteogenesis imperfecta (OI). OI is a heritable connective tissue disorder hallmarked by bone fragility resulting primarily from dominant mutations in the proα1(I) or proα2(I) collagen genes and the recently discovered recessive mutations in post-translational modifying proteins of type I collagen. In this study we examined the soleus (S), plantaris (P), gastrocnemius (G), tibialis anterior (TA) and quadriceps (Q) muscles of mice expressing mild (+/oim) and moderately severe (oim/oim) OI for evidence of inherent muscle pathology. In particular, muscle weight, fiber cross-sectional area (CSA), fiber type, fiber histomorphology, fibrillar collagen content, absolute, relative and specific peak tetanic force (P(o), P(o)/mg and P(o)/CSA respectively) of individual muscles were evaluated. Oim/oim mouse muscles were generally smaller, contained less fibrillar collagen, had decreased P(o) and an inability to sustain P(o) for the 300-ms testing duration for specific muscles; +/oim mice had a similar but milder skeletal muscle phenotype. +/oim mice had mild weakness of specific muscles but were less affected than their oim/oim counterparts which demonstrated readily apparent skeletal muscle pathology. Therefore muscle weakness in oim mice reflects inherent skeletal muscle pathology. Copyright © 2010 Elsevier B.V. All rights reserved.
Matrix groups for undergraduates
Tapp, Kristopher
Matrix groups touch an enormous spectrum of the mathematical arena. This textbook brings them into the undergraduate curriculum. It makes an excellent one-semester course for students familiar with linear and abstract algebra and prepares them for a graduate course on Lie groups. Matrix Groups for Undergraduates is concrete and example-driven, with geometric motivation and rigorous proofs. The story begins and ends with the rotations of a globe. In between, the author combines rigor and intuition to describe the basic objects of Lie theory: Lie algebras, matrix exponentiation, Lie brackets, maximal tori, homogeneous spaces, and roots. This second edition includes two new chapters that allow for an easier transition to the general theory of Lie groups. From reviews of the First Edition: This book could be used as an excellent textbook for a one semester course at university and it will prepare students for a graduate course on Lie groups, Lie algebras, etc. … The book combines an intuitive style of writing w...
Extracellular matrix structure.
Theocharis, Achilleas D; Skandalis, Spyros S; Gialeli, Chrysostomi; Karamanos, Nikos K
Extracellular matrix (ECM) is a non-cellular three-dimensional macromolecular network composed of collagens, proteoglycans/glycosaminoglycans, elastin, fibronectin, laminins, and several other glycoproteins. Matrix components bind each other as well as cell adhesion receptors forming a complex network into which cells reside in all tissues and organs. Cell surface receptors transduce signals into cells from ECM, which regulate diverse cellular functions, such as survival, growth, migration, and differentiation, and are vital for maintaining normal homeostasis. ECM is a highly dynamic structural network that continuously undergoes remodeling mediated by several matrix-degrading enzymes during normal and pathological conditions. Deregulation of ECM composition and structure is associated with the development and progression of several pathologic conditions. This article emphasizes in the complex ECM structure as to provide a better understanding of its dynamic structural and functional multipotency. Where relevant, the implication of the various families of ECM macromolecules in health and disease is also presented. Copyright © 2015 Elsevier B.V. All rights reserved.
Weak bones in diabetes mellitus - an update on pharmaceutical treatment options.
Lin, Daphne P L; Dass, Crispin R
Diabetes mellitus is often associated with a number of complications such as nephropathy, neuropathy, retinopathy and foot ulcers. However, weak bone is a diabetic complication that is often overlooked. Although the exact mechanism for weak bones within diabetes mellitus is unclear, studies have shown that the mechanism does differ in both type I (T1DM) and type II diabetes (T2DM). This review, however, investigates the application of mesenchymal stem cells, recombinant human bone morphogenetic protein-2, teriparatide, insulin administration and the effectiveness of a peroxisome proliferator-activated receptor-ϒ modulator, netoglitazone in the context of diabetic weak bones. In T1DM, weak bones may be the result of defective osteoblast activity, the absence of insulin's anabolic effects on bone, the deregulation of the bone-pancreas negative feedback loop and advanced glycation end product (AGE) aggregation within the bone matrix as a result of hyperglycaemia. Interestingly, T2DM patients placed on insulin administration, thiazolidinediones, SGLT2 inhibitors and sulfonylureas have an associated increased fracture risk. T2DM patients are also observed to have high sclerostin levels that impair osteoblast gene transcription, AGE aggregation within bone, which compromises bone strength and a decrease in esRAGE concentration resulting in a negative association with vertebral fractures. Effective treatment options for weak bones in the context of diabetes are currently lacking. There is certainly scope for discovery and development of novel agents that could alleviate this complication in diabetes patients. © 2017 Royal Pharmaceutical Society.
Policy-based benchmarking of weak heaps and their relatives
DEFF Research Database (Denmark)
Bruun, Asger; Edelkamp, Stefan; Katajainen, Jyrki
In this paper we describe an experimental study where we evaluated the practical efficiency of three worst-case efficient priority queues: 1) a weak heap that is a binary tree fulfilling half-heap ordering, 2) a weak queue that is a forest of perfect weak heaps, and 3) a runrelaxed weak queue tha...
Standard Errors for Matrix Correlations.
Ogasawara, Haruhiko
Derives the asymptotic standard errors and intercorrelations for several matrix correlations assuming multivariate normality for manifest variables and derives the asymptotic standard errors of the matrix correlations for two factor-loading matrices. (SLD)
Fisher.py: Fisher Matrix Manipulation and Confidence Contour Plotting
Coe, Dan
Fisher.py allows you to combine constraints from multiple experiments (e.g., weak lensing + supernovae) and add priors (e.g., a flat universe) simply and easily. Calculate parameter uncertainties and plot confidence ellipses. Fisher matrix expectations for several experiments are included as calculated by myself (time delays) and the Dark Energy Task Force (WL/SN/BAO/CL/CMB), or provide your own.
Riemann Geometric Color-Weak Compensationfor Individual Observers
Kojima, Takanori; Mochizuki, Rika; Lenz, Reiner; Chao, Jinhui
We extend a method for color weak compensation based on the criterion of preservation of subjective color differences between color normal and color weak observers presented in [2]. We introduce a new algorithm for color weak compensation using local affine maps between color spaces of color normal and color weak observers. We show howto estimate the local affine map and how to determine correspondences between the origins of local coordinates in color spaces of color normal and color weak ob...
Feasibility of isotachochromatography as a method for the preparative separation of weak acids and weak bases. I. Theoretical considerations
Kooistra, C.; Sluyterman, L.A.A.E.
The fundamental equation of isotachochromatography, i.e., isotachophoresis translated into ion-exchange chromatography, has been derived for weak acids and weak bases. Weak acids are separated on strong cation exchangers and weak bases on strong anion exchangers. According to theory, the elution
Systematic review: role of acid, weakly acidic and weakly alkaline reflux in gastro-oesophageal reflux disease
Boeckxstaens, G. E.; Smout, A.
The importance of weakly acidic and weakly alkaline reflux in gastro-oesophageal reflux disease (GERD) is gaining recognition. To quantify the proportions of reflux episodes that are acidic (pH <4), weakly acidic (pH 4-7) and weakly alkaline (pH >7) in adult patients with GERD, and to evaluate their
Strengths Weaknesses Opportunities and Threats of Blended Learning: Students' Perceptions
Hande, S
Background: Blended learning (BL) in a cell biology course of the premedical program at the Kasturba Medical College International Centre, Manipal, India, commenced in 2006. The program provides training in basic sciences to students, especially from the United States and Canada. The approach to the study was phenomenographic, with a qualitative study design using an open-ended questionnaire, focused interviews and empirical observations. Aim: The aim of this study was to identify the strengths, weaknesses, opportunities and threats (SWOT) of BL in a premedical class. Subjects and Methods: It was a cross-sectional study. Ninety six students in a premedical cell biology class participated in the study. SWOT analysis of students' perceptions was conducted manually. Statistical analysis included content analysis of qualitative data to classify data and aligning them into the SWOT analysis matrix. Results: The outcomes of the study revealed student perceptions in terms of SWOT of BL and the potential uses of this strategy. Conclusions: The study provides background for educators and curriculum experts to plan their modules while incorporating a BL approach. PMID:24971204
Strengths weaknesses opportunities and threats of blended learning: students' perceptions.
Hande, S
Blended learning (BL) in a cell biology course of the premedical program at the Kasturba Medical College International Centre, Manipal, India, commenced in 2006. The program provides training in basic sciences to students, especially from the United States and Canada. The approach to the study was phenomenographic, with a qualitative study design using an open-ended questionnaire, focused interviews and empirical observations. The aim of this study was to identify the strengths, weaknesses, opportunities and threats (SWOT) of BL in a premedical class. It was a cross-sectional study. Ninety six students in a premedical cell biology class participated in the study. SWOT analysis of students' perceptions was conducted manually. Statistical analysis included content analysis of qualitative data to classify data and aligning them into the SWOT analysis matrix. The outcomes of the study revealed student perceptions in terms of SWOT of BL and the potential uses of this strategy. The study provides background for educators and curriculum experts to plan their modules while incorporating a BL approach.
The cellulose resource matrix.
Keijsers, Edwin R P; Yılmaz, Gülden; van Dam, Jan E G
The emerging biobased economy is causing shifts from mineral fossil oil based resources towards renewable resources. Because of market mechanisms, current and new industries utilising renewable commodities, will attempt to secure their supply of resources. Cellulose is among these commodities, where large scale competition can be expected and already is observed for the traditional industries such as the paper industry. Cellulose and lignocellulosic raw materials (like wood and non-wood fibre crops) are being utilised in many industrial sectors. Due to the initiated transition towards biobased economy, these raw materials are intensively investigated also for new applications such as 2nd generation biofuels and 'green' chemicals and materials production (Clark, 2007; Lange, 2007; Petrus & Noordermeer, 2006; Ragauskas et al., 2006; Regalbuto, 2009). As lignocellulosic raw materials are available in variable quantities and qualities, unnecessary competition can be avoided via the choice of suitable raw materials for a target application. For example, utilisation of cellulose as carbohydrate source for ethanol production (Kabir Kazi et al., 2010) avoids the discussed competition with easier digestible carbohydrates (sugars, starch) deprived from the food supply chain. Also for cellulose use as a biopolymer several different competing markets can be distinguished. It is clear that these applications and markets will be influenced by large volume shifts. The world will have to reckon with the increase of competition and feedstock shortage (land use/biodiversity) (van Dam, de Klerk-Engels, Struik, & Rabbinge, 2005). It is of interest - in the context of sustainable development of the bioeconomy - to categorize the already available and emerging lignocellulosic resources in a matrix structure. When composing such "cellulose resource matrix" attention should be given to the quality aspects as well as to the available quantities and practical possibilities of processing the
Weak polyelectrolyte complexation driven by associative charging
Rathee, Vikramjit S.; Zervoudakis, Aristotle J.; Sidky, Hythem; Sikora, Benjamin J.; Whitmer, Jonathan K.
Weak polyelectrolytes are relevant for a wide range of fields; in particular, they have been investigated as "smart" materials for chemical separations and drug delivery. The charges on weak polyelectrolytes are dynamic, causing polymer chains to adopt different equilibrium conformations even with relatively small changes to the surrounding environment. Currently, there exists no comprehensive picture of this behavior, particularly where polymer-polymer interactions have the potential to affect charging properties significantly. In this study, we elucidate the novel interplay between weak polyelectrolyte charging and complexation behavior through coupled molecular dynamics and Monte Carlo simulations. Specifically, we investigate a model of two equal-length and oppositely charging polymer chains in an implicit salt solution represented through Debye-Hückel interactions. The charging tendency of each chain, along with the salt concentration, is varied to determine the existence and extent of cooperativity in charging and complexation. Strong cooperation in the charging of these chains is observed at large Debye lengths, corresponding to low salt concentrations, while at lower Debye lengths (higher salt concentrations), the chains behave in apparent isolation. When the electrostatic coupling is long-ranged, we find that a highly charged chain strongly promotes the charging of its partner chain, even if the environment is unfavorable for an isolated version of that partner chain. Evidence of this phenomenon is supported by a drop in the potential energy of the system, which does not occur at the lower Debye lengths where both potential energies and charge fractions converge for all partner chain charging tendencies. The discovery of this cooperation will be helpful in developing "smart" drug delivery mechanisms by allowing for better predictions for the dissociation point of delivery complexes.
The magnetosphere under weak solar wind forcing
Directory of Open Access Journals (Sweden)
C. J. Farrugia
Full Text Available The Earth's magnetosphere was very strongly disturbed during the passage of the strong shock and the following interacting ejecta on 21–25 October 2001. These disturbances included two intense storms (Dst*≈−250 and −180 nT, respectively. The cessation of this activity at the start of 24 October ushered in a peculiar state of the magnetosphere which lasted for about 28 h and which we discuss in this paper. The interplanetary field was dominated by the sunward component [B=(4.29±0.77, −0.30±0.71, 0.49±0.45 nT]. We analyze global indicators of geomagnetic disturbances, polar cap precipitation, ground magnetometer records, and ionospheric convection as obtained from SuperDARN radars. The state of the magnetosphere is characterized by the following features: (i generally weak and patchy (in time low-latitude dayside reconnection or reconnection poleward of the cusps; (ii absence of substorms; (iii a monotonic recovery from the previous storm activity (Dst corrected for magnetopause currents decreasing from ~−65 to ~−35 nT, giving an unforced decreased of ~1.1 nT/h; (iv the probable absence of viscous-type interaction originating from the Kelvin-Helmholtz (KH instability; (v a cross-polar cap potential of just 20–30 kV; (vi a persistent, polar cap region containing (vii very weak, and sometimes absent, electron precipitation and no systematic inter-hemisphere asymmetry. Whereas we therefore infer the presence of a moderate amount of open flux, the convection is generally weak and patchy, which we ascribe to the lack of solar wind driver. This magnetospheric state approaches that predicted by Cowley and Lockwood (1992 but has never yet been observed.
Spurious Shear in Weak Lensing with LSST
Energy Technology Data Exchange (ETDEWEB)
Chang, C.; Kahn, S.M.; Jernigan, J.G.; Peterson, J.R.; AlSayyad, Y.; Ahmad, Z.; Bankert, J.; Bard, D.; Connolly, A.; Gibson, R.R.; Gilmore, K.; Grace, E.; Hannel, M.; Hodge, M.A.; Jee, M.J.; Jones, L.; Krughoff, S.; Lorenz, S.; Marshall, P.J.; Marshall, S.; Meert, A.
The complete 10-year survey from the Large Synoptic Survey Telescope (LSST) will image {approx} 20,000 square degrees of sky in six filter bands every few nights, bringing the final survey depth to r {approx} 27.5, with over 4 billion well measured galaxies. To take full advantage of this unprecedented statistical power, the systematic errors associated with weak lensing measurements need to be controlled to a level similar to the statistical errors. This work is the first attempt to quantitatively estimate the absolute level and statistical properties of the systematic errors on weak lensing shear measurements due to the most important physical effects in the LSST system via high fidelity ray-tracing simulations. We identify and isolate the different sources of algorithm-independent, additive systematic errors on shear measurements for LSST and predict their impact on the final cosmic shear measurements using conventional weak lensing analysis techniques. We find that the main source of the errors comes from an inability to adequately characterise the atmospheric point spread function (PSF) due to its high frequency spatial variation on angular scales smaller than {approx} 10{prime} in the single short exposures, which propagates into a spurious shear correlation function at the 10{sup -4}-10{sup -3} level on these scales. With the large multi-epoch dataset that will be acquired by LSST, the stochastic errors average out, bringing the final spurious shear correlation function to a level very close to the statistical errors. Our results imply that the cosmological constraints from LSST will not be severely limited by these algorithm-independent, additive systematic effects.
Deift, Percy
This book features a unified derivation of the mathematical theory of the three classical types of invariant random matrix ensembles-orthogonal, unitary, and symplectic. The authors follow the approach of Tracy and Widom, but the exposition here contains a substantial amount of additional material, in particular, facts from functional analysis and the theory of Pfaffians. The main result in the book is a proof of universality for orthogonal and symplectic ensembles corresponding to generalized Gaussian type weights following the authors' prior work. New, quantitative error estimates are derive
Eisenman, Richard L
This outstanding text and reference applies matrix ideas to vector methods, using physical ideas to illustrate and motivate mathematical concepts but employing a mathematical continuity of development rather than a physical approach. The author, who taught at the U.S. Air Force Academy, dispenses with the artificial barrier between vectors and matrices--and more generally, between pure and applied mathematics.Motivated examples introduce each idea, with interpretations of physical, algebraic, and geometric contexts, in addition to generalizations to theorems that reflect the essential structur
Directory of Open Access Journals (Sweden)
Abdelhakim Chillali
Full Text Available In classical cryptography, the Hill cipher is a polygraphic substitution cipher based on linear algebra. In this work, we proposed a new problem applicable to the public key cryptography, based on the Matrices, called "Matrix discrete logarithm problem", it uses certain elements formed by matrices whose coefficients are elements in a finite field. We have constructed an abelian group and, for the cryptographic part in this unreliable group, we then perform the computation corresponding to the algebraic equations, Returning the encrypted result to a receiver. Upon receipt of the result, the receiver can retrieve the sender's clear message by performing the inverse calculation.
Matrix string partition function
Kostov, Ivan K; Kostov, Ivan K.; Vanhove, Pierre
We evaluate quasiclassically the Ramond partition function of Euclidean D=10 U(N) super Yang-Mills theory reduced to a two-dimensional torus. The result can be interpreted in terms of free strings wrapping the space-time torus, as expected from the point of view of Matrix string theory. We demonstrate that, when extrapolated to the ultraviolet limit (small area of the torus), the quasiclassical expressions reproduce exactly the recently obtained expression for the partition of the completely reduced SYM theory, including the overall numerical factor. This is an evidence that our quasiclassical calculation might be exact.
Non-neural Muscle Weakness Has Limited Influence on Complexity of Motor Control during Gait
Directory of Open Access Journals (Sweden)
Marije Goudriaan
Full Text Available Cerebral palsy (CP and Duchenne muscular dystrophy (DMD are neuromuscular disorders characterized by muscle weakness. Weakness in CP has neural and non-neural components, whereas in DMD, weakness can be considered as a predominantly non-neural problem. Despite the different underlying causes, weakness is a constraint for the central nervous system when controlling gait. CP demonstrates decreased complexity of motor control during gait from muscle synergy analysis, which is reflected by a higher total variance accounted for by one synergy (tVAF1. However, it remains unclear if weakness directly contributes to higher tVAF1 in CP, or whether altered tVAF1 reflects mainly neural impairments. If muscle weakness directly contributes to higher tVAF1, then tVAF1 should also be increased in DMD. To examine the etiology of increased tVAF1, muscle activity data of gluteus medius, rectus femoris, medial hamstrings, medial gastrocnemius, and tibialis anterior were measured at self-selected walking speed, and strength data from knee extensors, knee flexors, dorsiflexors and plantar flexors, were analyzed in 15 children with CP [median (IQR age: 8.9 (2.2], 15 boys with DMD [8.7 (3.1], and 15 typical developing (TD children [8.6 (2.7]. We computed tVAF1 from 10 concatenated steps with non-negative matrix factorization, and compared tVAF1 between the three groups with a Mann-Whiney U-test. Spearman's rank correlation coefficients were used to determine if weakness in specific muscle groups contributed to altered tVAF1. No significant differences in tVAF1 were found between DMD [tVAF1: 0.60 (0.07] and TD children [0.65 (0.07], while tVAF1 was significantly higher in CP [(0.74 (0.09] than in the other groups (both p < 0.005. In CP, weakness in the plantar flexors was related to higher tVAF1 (r = −0.72. In DMD, knee extensor weakness related to increased tVAF1 (r = −0.50. These results suggest that the non-neural weakness in DMD had limited influence on
Spectral line profiles in weakly turbulent plasmas
International Nuclear Information System (INIS)
Capes, H.; Voslamber, D.
The unified theory of line broadening by electron perturbers is generalized to include the case of a weakly turbulent plasma. The collision operator in the line shape expression is shown to be the sum of two terms, both containing effects arising from the non-equilibrium nature of the plasma. One of the two terms represents the influence of individual atom-particle interactions occuring via the nonequilibrium dielectric plasma medium. The other term is due to the interaction of the atom with the turbulent waves. Both terms contain damping and diffusion effects arising from the plasma turbulence
Weak mixing angles and heavy flavours
International Nuclear Information System (INIS)
Jarlskog, C.
The present status of the weak mixing angles, in the standard six quark model, is reviewed. The implications of the recent measurements of the beauty lifetime and branching ratios are discussed, in the framework of the Kobayashi-Maskawa and the Wolfenstein parametrizations. Expectations for B(sup)o - B(sup)-o mixing and consequences for the collider data are given. Other topics briefly reviewed are CP-violation, top quark mass and possible implications of the existence of a fourth family. (author)
Why is hydrofluoric acid a weak acid?
Ayotte, Patrick; Hébert, Martin; Marchand, Patrick
The infrared vibrational spectra of amorphous solid water thin films doped with HF at 40 K reveal a strong continuous absorbance in the 1000-3275 cm(-1) range. This so-called Zundel continuum is the spectroscopic hallmark for aqueous protons. The extensive ionic dissociation of HF at such low temperature suggests that the reaction enthalpy remains negative down to 40 K. These observations support the interpretation that dilute HF aqueous solutions behave as weak acids largely due to the large positive reaction entropy resulting from the structure making character of the hydrated fluoride ion.
Superconductor in a weak static gravitational field
Energy Technology Data Exchange (ETDEWEB)
Ummarino, Giovanni Alberto [Dipartimento DISAT, Politecnico di Torino, Turin (Italy); National Research Nuclear University MEPhI-Moscow Engineering Physics Institute, Moscow (Russian Federation); Gallerati, Antonio [Dipartimento DISAT, Politecnico di Torino, Turin (Italy)
We provide the detailed calculation of a general form for Maxwell and London equations that takes into account gravitational corrections in linear approximation. We determine the possible alteration of a static gravitational field in a superconductor making use of the time-dependent Ginzburg-Landau equations, providing also an analytic solution in the weak field condition. Finally, we compare the behavior of a high-T{sub c} superconductor with a classical low-T{sub c} superconductor, analyzing the values of the parameters that can enhance the reduction of the gravitational field. (orig.)
Unification of electromagnetic, strong and weak interaction
International Nuclear Information System (INIS)
Duong Van Phi; Duong Anh Duc
The Unification of Electromagnetic, Strong and Weak Interactions is realized in the framework of the Quantum Field Theory, established in an 8-dimensional Unified Space. Two fundamental, spinor and vector field equations are considered. The first of the matter particles and the second is of the gauge particles. Interaction Lagrangians are formed from the external and internal currents and the external and internal vector field operators. Generators of the local gauge transformations are the combinations of the matrices of the first field equation. (author). 15 refs
Relativistic rapprochement of weak and strong interactions
International Nuclear Information System (INIS)
Strel'tsov, V.N.
On the basis of the relativistic Yukawa potentials for the nuclear (quark) field and the field of intermediate vector W-, Z-bosons, it is shown that the interactions described by them increase differently with growing velocity (the weak one increases more rapidly). According to the estimates, they are compared (at distances of the 'action radius' of nuclear forces) at an energy of about 10 12 GeV (10 6 GeV for the pion field) what is smaller than the corresponding value in the model of 'grand unification'. 3 refs., 2 tabs
[The weakness of individual psychologic dream theory].
Strunz, F
This article undertakes a critical evaluation of Adlerian dream theory. The main weakness of the theory is found to be its lack of an inherent instance of truth that shows the dreamer the way to a better and more feasible life style. Contemporary Adlerians' treatment of the master's dream dogmas and their practical use in psychotherapy are described. There seems to be a convergence movement of today's practical application methods of the dream in all psychotherapeutic schools. Adlerian dream interpretation in the original sense intended by Adler is practised nowhere by psychotherapists today and seems largely antiquated.
Superconductivity in multilayer perovskite. Weak coupling analysis
International Nuclear Information System (INIS)
Koikegami, Shigeru; Yanagisawa, Takashi
We investigate the superconductivity of a three-dimensional d-p model with a multilayer perovskite structure on the basis of the second-order perturbation theory within the weak coupling framework. Our model has been designed with multilayer high-T c superconducting cuprates in mind. In our model, multiple Fermi surfaces appear, and the component of a superconducting gap function develops on each band. We have found that the multilayer structure can stabilize the superconductivity in a wide doping range. (author)
Weak measurement and its experimental realisation
International Nuclear Information System (INIS)
Flack, R; Hiley, B J
The relationship between the real part of the weak value of the momentum operator at a post selected position is discussed and the meaning of the experimentally determined stream-lines in the Toronto experiment of Kocsis et al is re-examined. We argue against interpreting the energy flow lines as photon trajectories. The possibility of performing an analogous experiment using atoms is proposed in order that a direct comparison can be made with the trajectories calculated by Philippidis, Dewdney and Hiley using the Bohm approach.
Weak field approximation of new general relativity
International Nuclear Information System (INIS)
Fukui, Masayasu; Masukawa, Junnichi
In the weak field approximation, gravitational field equations of new general relativity with arbitrary parameters are examined. Assuming a conservation law delta sup(μ)T sub(μν) = 0 of the energy-momentum tensor T sub(μν) for matter fields in addition to the usual one delta sup(ν)T sub(μν) = 0, we show that the linearized gravitational field equations are decomposed into equations for a Lorentz scalar field and symmetric and antisymmetric Lorentz tensor fields. (author)
New quark model with weak triplet
International Nuclear Information System (INIS)
Suzuki, T.; Hori, S.; Yamada, E.; Yamanashi, K.; Abe, Y.
We propose a new anomaly-free quark model with weak isotriplets for quarks. The ΔI=1/2 enhancement may be accounted for, the requirement of Golowich and Holstein being satisfied. There arises a mixing of left-handed charmed quarks with left-handed nucleonic ones - such mixing essentially gives an overall explanation of neutral-current effects, inclusive y distribution, the ratio sigma/sup T/(anti νd)/sigma/sup T/(νd), and copious dilepton events in ν and anti ν reactions
Excavating wide inclines in weak strata
Energy Technology Data Exchange (ETDEWEB)
Kuznetsov, N N [Ukrspetsstroiproekt (USSR)
Discusses schemes for excavation of transport inclines in surface mines under conditions of weak, unstable rocks characterized by a high water content. The schemes are aimed at maximum reduction of excavation operations without infringing the safety of personnel. Use of walking draglines (the EhSh-20/90, EhSh-100/100 and EhSh-10/70) is evaluated. Optimum schemes for incline excavation and determining optimum slope inclination are described on the example of the Berezovsk brown coal surface mine in the USSR. Efficiency of optimum schemes is analyzed: range of excavation, safety degree, landslide hazards, water influx rate, accident rate, etc.
Thermodynamics of Weakly Measured Quantum Systems.
Alonso, Jose Joaquin; Lutz, Eric; Romito, Alessandro
We consider continuously monitored quantum systems and introduce definitions of work and heat along individual quantum trajectories that are valid for coherent superposition of energy eigenstates. We use these quantities to extend the first and second laws of stochastic thermodynamics to the quantum domain. We illustrate our results with the case of a weakly measured driven two-level system and show how to distinguish between quantum work and heat contributions. We finally employ quantum feedback control to suppress detector backaction and determine the work statistics.
Energy Technology Data Exchange (ETDEWEB)
Ziebell, L. F.; Gaelzer, R. [Instituto de Física, UFRGS, Porto Alegre, RS (Brazil); Yoon, P. H. [Institute for Physical Science and Technology, University of Maryland, College Park, MD (United States); Pavan, J., E-mail: email@example.com, E-mail: firstname.lastname@example.com, E-mail: firstname.lastname@example.com, E-mail: email@example.com [Instituto de Física e Matemática, UFPel, Pelotas, RS (Brazil)
The plasma emission is the radiation mechanism responsible for solar type II and type III radio bursts. The first theory of plasma emission was put forth in the 1950s, but the rigorous demonstration of the process based upon first principles had been lacking. The present Letter reports the first complete numerical solution of electromagnetic weak turbulence equations. It is shown that the fundamental emission is dominant and unless the beam speed is substantially higher than the electron thermal speed, the harmonic emission is not likely to be generated. The present findings may be useful for validating reduced models and for interpreting particle-in-cell simulations.
DEFF Research Database (Denmark)
Kohlenbach, Ulrich
The so-called weak Konig's lemma WKL asserts the existence of an infinite path b in any infinite binary tree (given by a representing function f). Based on this principle one can formulate subsystems of higher-order arithmetic which allow to carry out very substantial parts of classical mathematics...... which-relative to PRA -implies the schema of 10-induction). In this setting one can consider also a uniform version UWKL of WKL which asserts the existence of a functional which selects uniformly in a given infinite binary tree f an infinite path f of that tree. This uniform version of WKL...
Matrix algebra for linear models
Gruber, Marvin H J
Matrix methods have evolved from a tool for expressing statistical problems to an indispensable part of the development, understanding, and use of various types of complex statistical analyses. This evolution has made matrix methods a vital part of statistical education. Traditionally, matrix methods are taught in courses on everything from regression analysis to stochastic processes, thus creating a fractured view of the topic. Matrix Algebra for Linear Models offers readers a unique, unified view of matrix analysis theory (where and when necessary), methods, and their applications. Written f
Matrix product formula for Macdonald polynomials
Cantini, Luigi; de Gier, Jan; Wheeler, Michael
We derive a matrix product formula for symmetric Macdonald polynomials. Our results are obtained by constructing polynomial solutions of deformed Knizhnik-Zamolodchikov equations, which arise by considering representations of the Zamolodchikov-Faddeev and Yang-Baxter algebras in terms of t-deformed bosonic operators. These solutions are generalized probabilities for particle configurations of the multi-species asymmetric exclusion process, and form a basis of the ring of polynomials in n variables whose elements are indexed by compositions. For weakly increasing compositions (anti-dominant weights), these basis elements coincide with non-symmetric Macdonald polynomials. Our formulas imply a natural combinatorial interpretation in terms of solvable lattice models. They also imply that normalizations of stationary states of multi-species exclusion processes are obtained as Macdonald polynomials at q = 1.
Matrix product formula for Macdonald polynomials
International Nuclear Information System (INIS)
Cantini, Luigi; Gier, Jan de; Michael Wheeler
We derive a matrix product formula for symmetric Macdonald polynomials. Our results are obtained by constructing polynomial solutions of deformed Knizhnik–Zamolodchikov equations, which arise by considering representations of the Zamolodchikov–Faddeev and Yang–Baxter algebras in terms of t-deformed bosonic operators. These solutions are generalized probabilities for particle configurations of the multi-species asymmetric exclusion process, and form a basis of the ring of polynomials in n variables whose elements are indexed by compositions. For weakly increasing compositions (anti-dominant weights), these basis elements coincide with non-symmetric Macdonald polynomials. Our formulas imply a natural combinatorial interpretation in terms of solvable lattice models. They also imply that normalizations of stationary states of multi-species exclusion processes are obtained as Macdonald polynomials at q = 1. (paper)
Characterization of supercapacitors matrix
Energy Technology Data Exchange (ETDEWEB)
Sakka, Monzer Al, E-mail: firstname.lastname@example.com [Vrije Universiteit Brussel, pleinlaan 2, B-1050 Brussels (Belgium); FEMTO-ST Institute, ENISYS Department, FCLAB, UFC-UTBM, bat.F, 90010 Belfort (France); Gualous, Hamid, E-mail: email@example.com [Laboratoire LUSAC, Universite de Caen Basse Normandie, Rue Louis Aragon - BP 78, 50130 Cherbourg-Octeville (France); Van Mierlo, Joeri [Vrije Universiteit Brussel, pleinlaan 2, B-1050 Brussels (Belgium)
This paper treats supercapacitors matrix characterization. In order to cut off transient power peaks and to compensate for the intrinsic limitations in embedded sources, the use of supercapacitors as a storage system is quite suitable, because of their appropriate electrical characteristics (huge capacitance, small series resistance, high specific energy, high specific power), direct storage (energy ready for use), and easy control by power electronic conversion. This use requires supercapacitors modules where several cells connected in serial and/or in parallel, thus a bypass system to balance the charging or the discharging of supercapacitors is required. In the matrix of supercapacitors, six elements of three parallel BCAP0350 supercapacitors in serial connections have been considered. This topology permits to reduce the number of the bypass circuits and it can work in degraded mode. Actually, it allows the system to have more reliability by providing power continually to the load even when there are one or more cells failed. Simulation and experimental results are presented and discussed.
Characterization of supercapacitors matrix
International Nuclear Information System (INIS)
Sakka, Monzer Al; Gualous, Hamid; Van Mierlo, Joeri
This paper treats supercapacitors matrix characterization. In order to cut off transient power peaks and to compensate for the intrinsic limitations in embedded sources, the use of supercapacitors as a storage system is quite suitable, because of their appropriate electrical characteristics (huge capacitance, small series resistance, high specific energy, high specific power), direct storage (energy ready for use), and easy control by power electronic conversion. This use requires supercapacitors modules where several cells connected in serial and/or in parallel, thus a bypass system to balance the charging or the discharging of supercapacitors is required. In the matrix of supercapacitors, six elements of three parallel BCAP0350 supercapacitors in serial connections have been considered. This topology permits to reduce the number of the bypass circuits and it can work in degraded mode. Actually, it allows the system to have more reliability by providing power continually to the load even when there are one or more cells failed. Simulation and experimental results are presented and discussed.
On the validity of cosmological Fisher matrix forecasts
International Nuclear Information System (INIS)
Wolz, Laura; Kilbinger, Martin; Weller, Jochen; Giannantonio, Tommaso
We present a comparison of Fisher matrix forecasts for cosmological probes with Monte Carlo Markov Chain (MCMC) posterior likelihood estimation methods. We analyse the performance of future Dark Energy Task Force (DETF) stage-III and stage-IV dark-energy surveys using supernovae, baryon acoustic oscillations and weak lensing as probes. We concentrate in particular on the dark-energy equation of state parameters w 0 and w a . For purely geometrical probes, and especially when marginalising over w a , we find considerable disagreement between the two methods, since in this case the Fisher matrix can not reproduce the highly non-elliptical shape of the likelihood function. More quantitatively, the Fisher method underestimates the marginalized errors for purely geometrical probes between 30%-70%. For cases including structure formation such as weak lensing, we find that the posterior probability contours from the Fisher matrix estimation are in good agreement with the MCMC contours and the forecasted errors only changing on the 5% level. We then explore non-linear transformations resulting in physically-motivated parameters and investigate whether these parameterisations exhibit a Gaussian behaviour. We conclude that for the purely geometrical probes and, more generally, in cases where it is not known whether the likelihood is close to Gaussian, the Fisher matrix is not the appropriate tool to produce reliable forecasts
The Biological Effects of Weak Electromagnetic Fields
International Nuclear Information System (INIS)
Algattawi, A.; Elshyrih, H.
Many studies investigated that weak electromagnetic fields remove calcium ions bound to the membranes of living cells, making them more likely to tear,. There is an enzyme that destroys DNA this enzyme leaking through the membranes of lysosomes explains the fragmentation of DNA. This case was seen in cells exposed to mobile phone signals. When this occurs in the germ line it reduces fertility and predicts genetic damage in future generations. Although leakage of calcium ions into the cytosol (the main part of the cell) accelerates the growth, but it also promotes the growth of tumors. Leakage of calcium ions into neurons (brain cells) makes nerve impulses accounting for pain and other neurological symptoms in electro sensitive. It also reduces the signal to noise ratio of the brain making it less likely to respond. This may be partially responsible for the increased accident rate of drivers using mobile phones. More details for the molecular mechanisms to explain characteristics of electromagnetic exposure are needed, e.g. I) why weak fields are more effective than strong ones, II) why some frequencies such as 16 Hz are especially potent and III) why pulsed fields do more damage
Critical potentials, leptons, and weak currents
International Nuclear Information System (INIS)
Smith, P.F.; Lewin, J.D.
A theoretical study is made of the interaction of very strong localised electromagnetic potentials with charged leptons, and with the vacuum state. The principal objective is to investigate the phenomena which occur when the potential reaches or exceeds the critical value at which bound levels are drawn into the lower continuum. The behaviour of bound and continuum solutions of the Dirac equation for the specific model of a short range potential well in an arbitrarily large bounded volume is examined in detail. Vacuum polarisation effects are computed by summation over the infinite set of single particle levels, and special attention is given to the behaviour of the overall charge distribution as the potential strength increases through the critical value. The most significant features of the results are (a) the formation of highly localised electron or muon bound states, (b) similar critical potential strengths for electrons and muons, and (c) redefinition of the vacuum by one charge unit at the critical potential. These features are analogous to some properties of leptonic and hadronic weak currents, and the hypothesis is proposed that strong short range potentials may provide a possible mediating mechanism for the weak interaction and also a lepton confinement mechanism within the structure of hadrons. (author)
Weak lensing of the Lyman α forest
Croft, Rupert A. C.; Romeo, Alessandro; Metcalf, R. Benton
The angular positions of quasars are deflected by the gravitational lensing effect of foreground matter. The Lyman α (Lyα) forest seen in the spectra of these quasars is therefore also lensed. We propose that the signature of weak gravitational lensing of the Lyα forest could be measured using similar techniques that have been applied to the lensed cosmic microwave background (CMB), and which have also been proposed for application to spectral data from 21-cm radio telescopes. As with 21-cm data, the forest has the advantage of spectral information, potentially yielding many lensed `slices' at different redshifts. We perform an illustrative idealized test, generating a high-resolution angular grid of quasars (of order arcminute separation), and lensing the Lyα forest spectra at redshifts z = 2-3 using a foreground density field. We find that standard quadratic estimators can be used to reconstruct images of the foreground mass distribution at z ˜ 1. There currently exists a wealth of Lyα forest data from quasar and galaxy spectral surveys, with smaller sightline separations expected in the future. Lyα forest lensing is sensitive to the foreground mass distribution at redshifts intermediate between CMB lensing and galaxy shear, and avoids the difficulties of shape measurement associated with the latter. With further refinement and application of mass reconstruction techniques, weak gravitational lensing of the high-redshift Lyα forest may become a useful new cosmological probe.
Weak pion production off the nucleon
International Nuclear Information System (INIS)
Hernandez, E.; Nieves, J.; Valverde, M.
We develop a model for the weak pion production off the nucleon, which besides the delta pole mechanism [weak excitation of the Δ(1232) resonance and its subsequent decay into Nπ], includes also some background terms required by chiral symmetry. We refit the C 5 A (q 2 ) form factor to the flux-averaged ν μ p→μ - pπ + ANL q 2 -differential cross section data, finding a substantially smaller contribution of the delta pole mechanism than traditionally assumed in the literature. Within this scheme, we calculate several differential and integrated cross sections, including pion angular distributions, induced by neutrinos and antineutrinos and driven both by charged and neutral currents. In all cases we find that the background terms produce quite significant effects, and that they lead to an overall improved description of the data, as compared to the case where only the delta pole mechanism is considered. We also show that the interference between the delta pole and the background terms produces parity-violating contributions to the pion angular differential cross section, which are intimately linked to T-odd correlations in the contraction between the leptonic and hadronic tensors. However, these latter correlations do not imply a genuine violation of time-reversal invariance because of the existence of strong final state interaction effects
Conformational transitions of a weak polyampholyte
Nair, Arun Kumar Narayanan
Using grand canonical Monte Carlo simulations of a flexible polyelectrolyte where the charges are in contact with a reservoir of constant chemical potential given by the solution pH, we study the behavior of weak polyelectrolytes in poor and good solvent conditions for polymer backbone. We address the titration behavior and conformational properties of a flexible diblock polyampholyte chain formed of two oppositely charged weak polyelectrolyte blocks, each containing equal number of identical monomers. The change of solution pH induces charge asymmetry in a diblock polyampholyte. For diblock polyampholyte chains in poor solvents, we demonstrate that a discontinuous transition between extended (tadpole) and collapsed (globular) conformational states is attainable by varying the solution pH. The double-minima structure in the probability distribution of the free energy provides direct evidence for the first-order like nature of this transition. At the isoelectric point electrostatically driven coil-globule transition of diblock polyampholytes in good solvents is found to consist of different regimes identified with increasing electrostatic interaction strength. At pH values above or below the isoelectric point diblock chains are found to have polyelectrolyte-like behavior due to repulsion between uncompensated charges along the chain.
Weak scale from the maximum entropy principle
Hamada, Yuta; Kawai, Hikaru; Kawana, Kiyoharu
The theory of the multiverse and wormholes suggests that the parameters of the Standard Model (SM) are fixed in such a way that the radiation of the S3 universe at the final stage S_rad becomes maximum, which we call the maximum entropy principle. Although it is difficult to confirm this principle generally, for a few parameters of the SM, we can check whether S_rad actually becomes maximum at the observed values. In this paper, we regard S_rad at the final stage as a function of the weak scale (the Higgs expectation value) vh, and show that it becomes maximum around vh = {{O}} (300 GeV) when the dimensionless couplings in the SM, i.e., the Higgs self-coupling, the gauge couplings, and the Yukawa couplings are fixed. Roughly speaking, we find that the weak scale is given by vh ˜ T_{BBN}2 / (M_{pl}ye5), where ye is the Yukawa coupling of electron, T_BBN is the temperature at which the Big Bang nucleosynthesis starts, and M_pl is the Planck mass.
Probing hysteretic elasticity in weakly nonlinear materials
Energy Technology Data Exchange (ETDEWEB)
Johnson, Paul A [Los Alamos National Laboratory; Haupert, Sylvain [UPMC UNIV PARIS; Renaud, Guillaume [UPMC UNIV PARIS; Riviere, Jacques [UPMC UNIV PARIS; Talmant, Maryline [UPMC UNIV PARIS; Laugier, Pascal [UPMC UNIV PARIS
Our work is aimed at assessing the elastic and dissipative hysteretic nonlinear parameters' repeatability (precision) using several classes of materials with weak, intermediate and high nonlinear properties. In this contribution, we describe an optimized Nonlinear Resonant Ultrasound Spectroscopy (NRUS) measuring and data processing protocol applied to small samples. The protocol is used to eliminate the effects of environmental condition changes that take place during an experiment, and that may mask the intrinsic elastic nonlinearity. As an example, in our experiments, we identified external temperature fluctuation as a primary source of material resonance frequency and elastic modulus variation. A variation of 0.1 C produced a frequency variation of 0.01 %, which is similar to the expected nonlinear frequency shift for weakly nonlinear materials. In order to eliminate environmental effects, the variation in f{sub 0} (the elastically linear resonance frequency proportional to modulus) is fit with the appropriate function, and that function is used to correct the NRUS calculation of nonlinear parameters. With our correction procedure, we measured relative resonant frequency shifts of 10{sup -5} , which are below 10{sup -4}, often considered the limit to NRUS sensitivity under common experimental conditions. Our results show that the procedure is an alternative to the stringent control of temperature often applied. Applying the approach, we report nonlinear parameters for several materials, some with very small nonclassical nonlinearity. The approach has broad application to NRUS and other Nonlinear Elastic Wave Spectroscopy approaches.
Conformational transitions of a weak polyampholyte
Nair, Arun Kumar Narayanan; Uyaver, Sahin; Sun, Shuyu
Using grand canonical Monte Carlo simulations of a flexible polyelectrolyte where the charges are in contact with a reservoir of constant chemical potential given by the solution pH, we study the behavior of weak polyelectrolytes in poor and good solvent conditions for polymer backbone. We address the titration behavior and conformational properties of a flexible diblock polyampholyte chain formed of two oppositely charged weak polyelectrolyte blocks, each containing equal number of identical monomers. The change of solution pH induces charge asymmetry in a diblock polyampholyte. For diblock polyampholyte chains in poor solvents, we demonstrate that a discontinuous transition between extended (tadpole) and collapsed (globular) conformational states is attainable by varying the solution pH. The double-minima structure in the probability distribution of the free energy provides direct evidence for the first-order like nature of this transition. At the isoelectric point electrostatically driven coil-globule transition of diblock polyampholytes in good solvents is found to consist of different regimes identified with increasing electrostatic interaction strength. At pH values above or below the isoelectric point diblock chains are found to have polyelectrolyte-like behavior due to repulsion between uncompensated charges along the chain.
Weak interactions in hot nucleon matter
International Nuclear Information System (INIS)
Cowell, S.; Pandharipande, V.R.
The reaction rates for electron capture, neutrino absorption, and neutrino scattering in hot asymmetric nuclear matter are calculated with two-body effective interactions and one-body effective weak operators obtained from realistic models of nuclear forces by use of correlated basis theory. The infinite system is modeled in a box with periodic boundary conditions, and the one-quasiparticle quasi-hole response functions are calculated with a large microcanonical sample and the Tamm-Dancoff approximation. Results for matter at a temperature of 10 MeV, proton fraction 0.4, and densities ρ=(1/2),1,(3/2)ρ 0 , where ρ 0 is the equilibrium density of symmetric nuclear matter, are presented to illustrate the method. In general, the strength of the response is shifted to higher-energy transfers when compared with that of a noninteracting Fermi gas. The shift in the response and the weakness of effective operators as compared with the bare operators significantly reduce the cross sections for electron capture and neutrino scattering by factors of ∼2.5-3.5. In contrast, the symmetry energy enhances the neutrino absorption reaction rate relative to the Fermi gas. However, this reaction rate is still quite small because of Pauli blocking
Ceramic matrix and resin matrix composites - A comparison
Hurwitz, Frances I.
The underlying theory of continuous fiber reinforcement of ceramic matrix and resin matrix composites, their fabrication, microstructure, physical and mechanical properties are contrasted. The growing use of organometallic polymers as precursors to ceramic matrices is discussed as a means of providing low temperature processing capability without the fiber degradation encountered with more conventional ceramic processing techniques. Examples of ceramic matrix composites derived from particulate-filled, high char yield polymers and silsesquioxane precursors are provided.
Ceramic matrix and resin matrix composites: A comparison
Hurwitz, Frances I.
The underlying theory of continuous fiber reinforcement of ceramic matrix and resin matrix composites, their fabrication, microstructure, physical and mechanical properties are contrasted. The growing use of organometallic polymers as precursors to ceramic matrices is discussed as a means of providing low temperature processing capability without the fiber degradation encountered with more conventional ceramic processing techniques. Examples of ceramic matrix composites derived from particulate-filled, high char yield polymers and silsesquioxane precursors are provided.
International Nuclear Information System (INIS)
Craps, Ben; Sethi, Savdeep; Verlinde, Erik
The light-like linear dilaton background represents a particularly simple time-dependent 1/2 BPS solution of critical type-IIA superstring theory in ten dimensions. Its lift to M-theory, as well as its Einstein frame metric, are singular in the sense that the geometry is geodesically incomplete and the Riemann tensor diverges along a light-like subspace of codimension one. We study this background as a model for a big bang type singularity in string theory/M-theory. We construct the dual Matrix theory description in terms of a (1+1)-d supersymmetric Yang-Mills theory on a time-dependent world-sheet given by the Milne orbifold of (1+1)-d Minkowski space. Our model provides a framework in which the physics of the singularity appears to be under control
Energy Technology Data Exchange (ETDEWEB)
Craps, Ben [Instituut voor Theoretische Fysica, Universiteit van Amsterdam, Valckenierstraat 65, 1018 XE Amsterdam (Netherlands); Sethi, Savdeep [Enrico Fermi Institute, University of Chicago, Chicago, IL 60637 (United States); Verlinde, Erik [Instituut voor Theoretische Fysica, Universiteit van Amsterdam, Valckenierstraat 65, 1018 XE Amsterdam (Netherlands)
The light-like linear dilaton background represents a particularly simple time-dependent 1/2 BPS solution of critical type-IIA superstring theory in ten dimensions. Its lift to M-theory, as well as its Einstein frame metric, are singular in the sense that the geometry is geodesically incomplete and the Riemann tensor diverges along a light-like subspace of codimension one. We study this background as a model for a big bang type singularity in string theory/M-theory. We construct the dual Matrix theory description in terms of a (1+1)-d supersymmetric Yang-Mills theory on a time-dependent world-sheet given by the Milne orbifold of (1+1)-d Minkowski space. Our model provides a framework in which the physics of the singularity appears to be under control.
Matrix metalloproteinases outside vertebrates.
Marino-Puertas, Laura; Goulas, Theodoros; Gomis-Rüth, F Xavier
The matrix metalloproteinase (MMP) family belongs to the metzincin clan of zinc-dependent metallopeptidases. Due to their enormous implications in physiology and disease, MMPs have mainly been studied in vertebrates. They are engaged in extracellular protein processing and degradation, and present extensive paralogy, with 23 forms in humans. One characteristic of MMPs is a ~165-residue catalytic domain (CD), which has been structurally studied for 14 MMPs from human, mouse, rat, pig and the oral-microbiome bacterium Tannerella forsythia. These studies revealed close overall coincidence and characteristic structural features, which distinguish MMPs from other metzincins and give rise to a sequence pattern for their identification. Here, we reviewed the literature available on MMPs outside vertebrates and performed database searches for potential MMP CDs in invertebrates, plants, fungi, viruses, protists, archaea and bacteria. These and previous results revealed that MMPs are widely present in several copies in Eumetazoa and higher plants (Tracheophyta), but have just token presence in eukaryotic algae. A few dozen sequences were found in Ascomycota (within fungi) and in double-stranded DNA viruses infecting invertebrates (within viruses). In contrast, a few hundred sequences were found in archaea and >1000 in bacteria, with several copies for some species. Most of the archaeal and bacterial phyla containing potential MMPs are present in human oral and gut microbiomes. Overall, MMP-like sequences are present across all kingdoms of life, but their asymmetric distribution contradicts the vertical descent model from a eubacterial or archaeal ancestor. This article is part of a Special Issue entitled: Matrix Metalloproteinases edited by Rafael Fridman. Copyright © 2017 Elsevier B.V. All rights reserved.
The Effect of Acid pH Modifiers on the Release Characteristics of Weakly Basic Drug from Hydrophlilic–Lipophilic Matrices
Dvořáčková, Kateřina; Doležel, Petr; Mašková, Eliška; Muselík, Jan; Kejdušová, Martina; Vetchý, David
The solubility of weakly basic drugs within passage though GI tract leads to pH-dependent or even incomplete release of these drugs from extended release formulations and consequently to lower drug absorption and bioavailability. The aim of the study was to prepare and evaluate hydrophilic–lipophilic (hypromellose–montanglycol wax) matrix tablets ensuring the pH-independent delivery of the weakly basic drug verapamil-hydrochloride by an incorporation of three organic acidifiers (citric, fumar...
Weak mixing and CP-violation involving heavy quarks and possible measurements in e+e- experiments
International Nuclear Information System (INIS)
Ali, A.; Aydin, Z.Z.
We evaluate weak mass mixing among the neutral heavy mesons with a bottom (Q = -1/3) or top (Q = +2/3) quark and CP-violation in the frame work of six quark (V - A) models. It is argued that bottom and top mesons may distinguish the Higgs exchange mechanism of CP-violation from a complex phase in the quark mass matrix, if bottom and top quark masses are sufficiently different. Estimates of weak mixing-and CP-violating effects for e + e - experiments at PETRA, PEP and CESR energies are presented. (orig.) [de
Meson exchange and neutral weak currents
Energy Technology Data Exchange (ETDEWEB)
Beck, D.H. [Univ. of Illinois, Urbana, IL (United States)
Measurements of parity-violating electron scattering asymmetries to determine weak neutral currents in nuclei will be effected by the presence of meson exchange currents. Present low momentum transfer calculations, based on a flavor independent framework, show these effects to be small. In general, however, as the momentum transfer increases to values typical of deep-inelastic scattering, fragmentation functions show a clear flavor dependence. It is suggested that a good experimental starting point for understanding the flavor dependence of meson production and exchange currents is the Q{sup 2} dependence of parity-violating asymmetry in inclusive single pion electroproduction. A CEBAF facility with doubled energy is necessary to approach momentum transfers where this process begins to scale.
Astrophysical evidence for weak new forces
International Nuclear Information System (INIS)
Burgess, C.; Cloutier, J.
Recent observations of the orbital precession rate for eclipsing binary star systems appear to be in disagreement with the predictions of general relativity. We here analyse whether these discrepancies can be interpreted as being due to the existence of a new, long range, very weak force. We find that, with a conservative estimate of the astrophysical errors involved, the binary-star data by itself is consistent with what would be expected of a new force. The coupling and range required to fit the data can be consistent with the present limits on the existence of new forces. The strongest constraints come from recent terrestrial searches for a ''fifth force''. This analysis underlines the fact that these binary star systems are sensitive to forces whose coupling strength can be as low as 10 -5 that of gravity
Weak lensing cosmology beyond ΛCDM
International Nuclear Information System (INIS)
Das, Sudeep; Linder, Eric V.; Nakajima, Reiko; Putter, Roland de
Weak gravitational lensing is one of the key probes of the cosmological model, dark energy, and dark matter, providing insight into both the cosmic expansion history and large scale structure growth history. Taking into account a broad spectrum of physics affecting growth — dynamical dark energy, extended gravity, neutrino masses, and spatial curvature — we analyze the cosmological constraints. Similarly we consider the effects of a range of systematic uncertainties, in shear measurement, photometric redshifts, intrinsic alignments, and the nonlinear power spectrum, on cosmological parameter extraction. We also investigate, and provide fitting formulas for, the influence of survey parameters such as redshift depth, galaxy number densities, and sky area on the cosmological constraints in the beyond-ΛCDM parameter space. Finally, we examine the robustness of results for different fiducial cosmologies
General gauge mediation at the weak scale
Energy Technology Data Exchange (ETDEWEB)
Knapen, Simon [Berkeley Center for Theoretical Physics,University of California, Berkeley, CA 94720 (United States); Theoretical Physics Group, Lawrence Berkeley National Laboratory,Berkeley, CA 94720 (United States); Redigolo, Diego [Sorbonne Universités, UPMC Univ Paris 06,UMR 7589, LPTHE, F-75005, Paris (France); CNRS, UMR 7589,LPTHE, F-75005, Paris (France); Shih, David [New High Energy Theory Center, Rutgers University,Piscataway, NJ 08854 (United States)
We completely characterize General Gauge Mediation (GGM) at the weak scale by solving all IR constraints over the full parameter space. This is made possible through a combination of numerical and analytical methods, based on a set of algebraic relations among the IR soft masses derived from the GGM boundary conditions in the UV. We show how tensions between just a few constraints determine the boundaries of the parameter space: electroweak symmetry breaking (EWSB), the Higgs mass, slepton tachyons, and left-handed stop/sbottom tachyons. While these constraints allow the left-handed squarks to be arbitrarily light, they place strong lower bounds on all of the right-handed squarks. Meanwhile, light EW superpartners are generic throughout much of the parameter space. This is especially the case at lower messenger scales, where a positive threshold correction to m{sub h} coming from light Higgsinos and winos is essential in order to satisfy the Higgs mass constraint.
Poisson equation for weak gravitational lensing
International Nuclear Information System (INIS)
Kling, Thomas P.; Campbell, Bryan
Using the Newman and Penrose [E. T. Newman and R. Penrose, J. Math. Phys. (N.Y.) 3, 566 (1962).] spin-coefficient formalism, we examine the full Bianchi identities of general relativity in the context of gravitational lensing, where the matter and space-time curvature are projected into a lens plane perpendicular to the line of sight. From one component of the Bianchi identity, we provide a rigorous, new derivation of a Poisson equation for the projected matter density where the source term involves second derivatives of the observed weak gravitational lensing shear. We also show that the other components of the Bianchi identity reveal no new results. Numerical integration of the Poisson equation in test cases shows an accurate mass map can be constructed from the combination of a ground-based, wide-field image and a Hubble Space Telescope image of the same system
Casimir apparatuses in a weak gravitational field
DEFF Research Database (Denmark)
Bimonte, Giuseppe; Calloni, Enrico; Esposito, Giampiero
We review and assess a part of the recent work on Casimir apparatuses in the weak gravitational field of the Earth. For a free, real massless scalar field subject to Dirichlet or Neumann boundary conditions on the parallel plates, the resulting regularized and renormalized energy-momentum tensor...... is covariantly conserved, while the trace anomaly vanishes if the massless field is conformally coupled to gravity. Conformal coupling also ensures a finite Casimir energy and finite values of the pressure upon parallel plates. These results have been extended to an electromagnetic field subject to perfect...... conductor (hence idealized) boundary conditions on parallel plates, by various authors. The regularized and renormalized energy-momentum tensor has beene valuated up to second order in the gravity acceleration. In both the scalar and the electromagnetic case, studied to first order in the gravity...
Gluon Bremsstrahlung in Weakly-Coupled Plasmas
International Nuclear Information System (INIS)
Arnold, Peter
I report on some theoretical progress concerning the calculation of gluon bremsstrahlung for very high energy particles crossing a weakly-coupled quark-gluon plasma. (i) I advertise that two of the several formalisms used to study this problem, the BDMPS-Zakharov formalism and the AMY formalism (the latter used only for infinite, uniform media), can be made equivalent when appropriately formulated. (ii) A standard technique to simplify calculations is to expand in inverse powers of logarithms ln(E/T). I give an example where such expansions are found to work well for ω/T≥10 where ω is the bremsstrahlung gluon energy. (iii) Finally, I report on perturbative calculations of q.
Strong mobility in weakly disordered systems
Energy Technology Data Exchange (ETDEWEB)
Ben-naim, Eli [Los Alamos National Laboratory; Krapivsky, Pavel [BOSTON UNIV
We study transport of interacting particles in weakly disordered media. Our one-dimensional system includes (i) disorder, the hopping rate governing the movement of a particle between two neighboring lattice sites is inhomogeneous, and (ii) hard core interaction, the maximum occupancy at each site is one particle. We find that over a substantial regime, the root-mean-square displacement of a particle s grows superdiffusively with time t, {sigma}{approx}({epsilon}t){sup 2/3}, where {epsilon} is the disorder strength. Without disorder the particle displacement is subdiffusive, {sigma} {approx}t{sup 1/4}, and therefore disorder strongly enhances particle mobility. We explain this effect using scaling arguments, and verify the theoretical predictions through numerical simulations. Also, the simulations show that regardless of disorder strength, disorder leads to stronger mobility over an intermediate time regime.
Acoustic radiation from weakly wrinkled premixed flames
Energy Technology Data Exchange (ETDEWEB)
Lieuwen, Tim; Mohan, Sripathi; Rajaram, Rajesh; Preetham, [School of Aerospace Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0150 (United States)
This paper describes a theoretical analysis of acoustic radiation from weakly wrinkled (i.e., u'/S{sub L}<1) premixed flames. Specifically, it determines the transfer function relating the spectrum of the acoustic pressure oscillations, P'({omega}), to that of the turbulent velocity fluctuations in the approach flow, U'({omega}). In the weakly wrinkled limit, this transfer function is local in frequency space; i.e., velocity fluctuations at a frequency {omega} distort the flame and generate sound at the same frequency. This transfer function primarily depends upon the flame Strouhal number St (based on mean flow velocity and flame length) and the correlation length, {lambda}, of the flow fluctuations. For cases where the ratio of the correlation length and duct radius {lambda}/a>>1, the acoustic pressure and turbulent velocity power spectra are related by P'({omega})-{omega}{sup 2}U'({omega}) and P'({omega})-U'({omega}) for St<<1 and St>>1, respectively. For cases where {lambda}/a<<1, the transfer functions take the form P'({omega})-{omega}{sup 2}({lambda}/a){sup 2}U'({omega}) and P'({omega})-{omega}{sup 2}({lambda}/a){sup 2}({psi}-{delta}ln({lambda}/a))U'({omega}) for St<<1 and St>>1, respectively, where (PS) and {delta} are constants. The latter result demonstrates that this transfer function does not exhibit a simple power law relationship in the high frequency region of the spectra. The simultaneous dependence of this pressure-velocity transfer function upon the Strouhal number and correlation length suggests a mechanism for the experimentally observed maximum in acoustic spectra and provides some insight into the controversy in the literature over how this peak should scale with the flame Strouhal number.
Weak links in high critical temperature superconductors
Tafuri, Francesco; Kirtley, John R.
The traditional distinction between tunnel and highly transmissive barriers does not currently hold for high critical temperature superconducting Josephson junctions, both because of complicated materials issues and the intrinsic properties of high temperature superconductors (HTS). An intermediate regime, typical of both artificial superconductor-barrier-superconductor structures and of grain boundaries, spans several orders of magnitude in the critical current density and specific resistivity. The physics taking place at HTS surfaces and interfaces is rich, primarily because of phenomena associated with d-wave order parameter (OP) symmetry. These phenomena include Andreev bound states, the presence of the second harmonic in the critical current versus phase relation, a doubly degenerate state, time reversal symmetry breaking and the possible presence of an imaginary component of the OP. All these effects are regulated by a series of transport mechanisms, whose rules of interplay and relative activation are unknown. Some transport mechanisms probably have common roots, which are not completely clear and possibly related to the intrinsic nature of high-TC superconductivity. The d-wave OP symmetry gives unique properties to HTS weak links, which do not have any analogy with systems based on other superconductors. Even if the HTS structures are not optimal, compared with low critical temperature superconductor Josephson junctions, the state of the art allows the realization of weak links with unexpectedly high quality quantum properties, which open interesting perspectives for the future. The observation of macroscopic quantum tunnelling and the qubit proposals represent significant achievements in this direction. In this review we attempt to encompass all the above aspects, attached to a solid experimental basis of junction concepts and basic properties, along with a flexible phenomenological background, which collects ideas on the Josephson effect in the presence
Weak links in high critical temperature superconductors
International Nuclear Information System (INIS)
Tafuri, Francesco; Kirtley, John R
The traditional distinction between tunnel and highly transmissive barriers does not currently hold for high critical temperature superconducting Josephson junctions, both because of complicated materials issues and the intrinsic properties of high temperature superconductors (HTS). An intermediate regime, typical of both artificial superconductor-barrier-superconductor structures and of grain boundaries, spans several orders of magnitude in the critical current density and specific resistivity. The physics taking place at HTS surfaces and interfaces is rich, primarily because of phenomena associated with d-wave order parameter (OP) symmetry. These phenomena include Andreev bound states, the presence of the second harmonic in the critical current versus phase relation, a doubly degenerate state, time reversal symmetry breaking and the possible presence of an imaginary component of the OP. All these effects are regulated by a series of transport mechanisms, whose rules of interplay and relative activation are unknown. Some transport mechanisms probably have common roots, which are not completely clear and possibly related to the intrinsic nature of high-T C superconductivity. The d-wave OP symmetry gives unique properties to HTS weak links, which do not have any analogy with systems based on other superconductors. Even if the HTS structures are not optimal, compared with low critical temperature superconductor Josephson junctions, the state of the art allows the realization of weak links with unexpectedly high quality quantum properties, which open interesting perspectives for the future. The observation of macroscopic quantum tunnelling and the qubit proposals represent significant achievements in this direction. In this review we attempt to encompass all the above aspects, attached to a solid experimental basis of junction concepts and basic properties, along with a flexible phenomenological background, which collects ideas on the Josephson effect in the presence
Super symmetry in strong and weak interactions
International Nuclear Information System (INIS)
Seshavatharam, U.V.S.; Lakshminarayana, S.
For strong interaction two new fermion mass units 105.32 MeV and 11450 MeV are assumed. Existence of "Integral charge quark bosons", "Integral charge effective quark fermions", "Integral charge (effective) quark fermi-gluons" and "Integral charge quark boso-gluons" are assumed and their masses are estimated. It is noticed that, characteristic nuclear charged fermion is X s · 105.32 = 938.8 MeV and corresponding charged boson is X s (105.32/x) = 415.0 where X s = 8.914 is the inverse of the strong coupling constant and x = 2.26234 is a new number by using which "super symmetry" can be seen in "strong and weak" interactions. 11450 MeV fermion and its boson of mass = 11450/x = 5060 MeV plays a crucial role in "sub quark physics" and "weak interaction". 938.8 MeV strong fermion seems to be the proton. 415 MeV strong boson seems to be the mother of the presently believed 493,496 and 547 MeV etc, strange mesons. With 11450 MeV fermion "effective quark-fermi-gluons" and with 5060 MeV boson "quark boso-gluon masses" are estimated. "Effective quark fermi-gluons" plays a crucial role in ground state charged baryons mass generation. Light quark bosons couple with these charged baryons to form doublets and triplets. "Quark boso-gluons" plays a crucial role in ground state neutral and charged mesons mass generation. Fine and super-fine rotational levels can be given by [I or (I/2)] power(1/4) and [I or (I/2)] power(1/12) respectively. Here, I = n(n+1) and n = 1, 2, 3, … (author)
Pre-relaxation in weakly interacting models
Bertini, Bruno; Fagotti, Maurizio
We consider time evolution in models close to integrable points with hidden symmetries that generate infinitely many local conservation laws that do not commute with one another. The system is expected to (locally) relax to a thermal ensemble if integrability is broken, or to a so-called generalised Gibbs ensemble if unbroken. In some circumstances expectation values exhibit quasi-stationary behaviour long before their typical relaxation time. For integrability-breaking perturbations, these are also called pre-thermalisation plateaux, and emerge e.g. in the strong coupling limit of the Bose-Hubbard model. As a result of the hidden symmetries, quasi-stationarity appears also in integrable models, for example in the Ising limit of the XXZ model. We investigate a weak coupling limit, identify a time window in which the effects of the perturbations become significant and solve the time evolution through a mean-field mapping. As an explicit example we study the XYZ spin-\\frac{1}{2} chain with additional perturbations that break integrability. One of the most intriguing results of the analysis is the appearance of persistent oscillatory behaviour. To unravel its origin, we study in detail a toy model: the transverse-field Ising chain with an additional nonlocal interaction proportional to the square of the transverse spin per unit length (2013 Phys. Rev. Lett. 111 197203). Despite being nonlocal, this belongs to a class of models that emerge as intermediate steps of the mean-field mapping and shares many dynamical properties with the weakly interacting models under consideration.
Anomalous baryogenesis at the weak scale
Energy Technology Data Exchange (ETDEWEB)
Singleton, R.L. Jr.
One of the fundamental constants of nature is the baryon asymmetry of the universe -- the ratio of the number of baryons to the entropy. This constant is about 10{sup {minus}11}. In baryon- number conserving theories, this was just an initial condition. With the advent of the grand unified theories (GUTs), baryon number is no longer conserved, and this asymmetry can be generated dynamically. Unfortunately, however, there are reasons for preferring another mechanism. For example, GUTs predict proton decay which, after extensive searches, has not been found. An alternative place to look for baryogenesis is the electroweak phase transition, described by the standard model, which posses all the necessary ingredients for baryogenesis. Anomalous baryon-number violation in weak interactions becomes large at high temperatures, which offers the prospect of creating the asymmetry with the standard model or minimal extensions. This can just barely be done if certain conditions are fulfilled. CP violation must be large, which rules out the minimal standard model as the source of the asymmetry, but which is easily arranged with an extended Higgs sector. The baryon-number violating rates themselves are not exactly known, and they must be pushed to their theoretical limits. A more exact determination of these rates is needed before a definitive answer can be given. Finally, the phase transition must be at least weakly first order. Such phase transitions are accompanied by the formation and expansion of bubbles of true vacuum within the false vacuum, much like the boiling of water. As the bubbles expand, they provide a departure from thermal equilibrium, otherwise the dynamics will adjust the net baryon number to zero. The bubble expansion also provides a biasing that creates an asymmetry on the bubbles surface. Under optimal conditions, the observed asymmetry can just be produced. 31 refs., 10 figs.
Normal modes of weak colloidal gels
Varga, Zsigmond; Swan, James W.
The normal modes and relaxation rates of weak colloidal gels are investigated in calculations using different models of the hydrodynamic interactions between suspended particles. The relaxation spectrum is computed for freely draining, Rotne-Prager-Yamakawa, and accelerated Stokesian dynamics approximations of the hydrodynamic mobility in a normal mode analysis of a harmonic network representing several colloidal gels. We find that the density of states and spatial structure of the normal modes are fundamentally altered by long-ranged hydrodynamic coupling among the particles. Short-ranged coupling due to hydrodynamic lubrication affects only the relaxation rates of short-wavelength modes. Hydrodynamic models accounting for long-ranged coupling exhibit a microscopic relaxation rate for each normal mode, λ that scales as l-2, where l is the spatial correlation length of the normal mode. For the freely draining approximation, which neglects long-ranged coupling, the microscopic relaxation rate scales as l-γ, where γ varies between three and two with increasing particle volume fraction. A simple phenomenological model of the internal elastic response to normal mode fluctuations is developed, which shows that long-ranged hydrodynamic interactions play a central role in the viscoelasticity of the gel network. Dynamic simulations of hard spheres that gel in response to short-ranged depletion attractions are used to test the applicability of the density of states predictions. For particle concentrations up to 30% by volume, the power law decay of the relaxation modulus in simulations accounting for long-ranged hydrodynamic interactions agrees with predictions generated by the density of states of the corresponding harmonic networks as well as experimental measurements. For higher volume fractions, excluded volume interactions dominate the stress response, and the prediction from the harmonic network density of states fails. Analogous to the Zimm model in polymer
Anomalous baryogenesis at the weak scale
International Nuclear Information System (INIS)
Singleton, R.L. Jr.
One of the fundamental constants of nature is the baryon asymmetry of the universe -- the ratio of the number of baryons to the entropy. This constant is about 10 -11 . In baryon- number conserving theories, this was just an initial condition. With the advent of the grand unified theories (GUTs), baryon number is no longer conserved, and this asymmetry can be generated dynamically. Unfortunately, however, there are reasons for preferring another mechanism. For example, GUTs predict proton decay which, after extensive searches, has not been found. An alternative place to look for baryogenesis is the electroweak phase transition, described by the standard model, which posses all the necessary ingredients for baryogenesis. Anomalous baryon-number violation in weak interactions becomes large at high temperatures, which offers the prospect of creating the asymmetry with the standard model or minimal extensions. This can just barely be done if certain conditions are fulfilled. CP violation must be large, which rules out the minimal standard model as the source of the asymmetry, but which is easily arranged with an extended Higgs sector. The baryon-number violating rates themselves are not exactly known, and they must be pushed to their theoretical limits. A more exact determination of these rates is needed before a definitive answer can be given. Finally, the phase transition must be at least weakly first order. Such phase transitions are accompanied by the formation and expansion of bubbles of true vacuum within the false vacuum, much like the boiling of water. As the bubbles expand, they provide a departure from thermal equilibrium, otherwise the dynamics will adjust the net baryon number to zero. The bubble expansion also provides a biasing that creates an asymmetry on the bubbles surface. Under optimal conditions, the observed asymmetry can just be produced. 31 refs., 10 figs
Semileptonic weak and electromagnetic interactions in nuclei: recoil polarization in muon capture
International Nuclear Information System (INIS)
Rosenfelder, R.
An analysis of the polarization of the recoiling nucleus following the capture of polarized muons by nuclei is performed. New general expressions for arbitrary nuclear spin are obtained in terms of the same reduced matrix elements which govern inelastic electron scattering and β-decay. As an application the A = 12 system is considered and uncertainties in the nuclear structure are studied by using different sets of one-body density matrices. With the canonical values of the weak form factors (i.e. absence of second-class currents) a fairly good agreement with the experimental data is achieved including the inelastic form factor at high momentum transfers and the recently measured average 12 B polarization. Implications of the new corrected value of the average polarization on weak form factors and nuclear structure are discussed. (Auth.)
Classical integrability for three-point functions: cognate structure at weak and strong couplings
Energy Technology Data Exchange (ETDEWEB)
Kazama, Yoichi [Research Center for Mathematical Physics, Rikkyo University,Toshima-ku, Tokyo 171-8501 (Japan); Quantum Hadron Physics Laboratory, RIKEN Nishina Center, Wako 351-0198 (Japan); Institute of Physics, University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902 (Japan); Komatsu, Shota [Perimeter Institute for Theoretical Physics,31 Caroline Street North, Waterloo, Ontario, N2L 2Y5 (Canada); Nishimura, Takuya [Institute of Physics, University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902 (Japan)
In this paper, we develop a new method of computing three-point functions in the SU(2) sector of the N=4 super Yang-Mills theory in the semi-classical regime at weak coupling, which closely parallels the strong coupling analysis. The structure threading two disparate regimes is the so-called monodromy relation, an identity connecting the three-point functions with and without the insertion of the monodromy matrix. We shall show that this relation can be put to use directly for the semi-classical regime, where the dynamics is governed by the classical Landau-Lifshitz sigma model. Specifically, it reduces the problem to a set of functional equations, which can be solved once the analyticity in the spectral parameter space is specified. To determine the analyticity, we develop a new universal logic applicable at both weak and strong couplings. As a result, compact semi-classical formulas are obtained for a general class of three-point functions at weak coupling including the ones whose semi-classical behaviors were not known before. In addition, the new analyticity argument applied to the strong coupling analysis leads to a modification of the integration contour, producing the results consistent with the recent hexagon bootstrap approach. This modification also makes the Frolov-Tseytlin limit perfectly agree with the weak coupling form.
Analysis of Service Quality Management in the Materials Industry using the BCG Matrix Method
Adrian Ioana; Vasile Mirea; Cezar Balescu
For each product or service, the area of the circle represents the value of its sales. The BCG (Boston Consulting Group) matrix thus offers a very useful map of the organization's service strengths and weaknesses, at least in terms of current profitability, as well as the likely cash flows. The criteria function concept consists of transforming the criteria function (CF) in a qualityeconomical matrix MQE. The levels of prescribing the criteria function were obtained by using a composition alg...
Magnified Weak Lensing Cross Correlation Tomography
Energy Technology Data Exchange (ETDEWEB)
Ulmer, Melville P., Clowe, Douglas I.
This project carried out a weak lensing tomography (WLT) measurement around rich clusters of galaxies. This project used ground based photometric redshift data combined with HST archived cluster images that provide the WLT and cluster mass modeling. The technique has already produced interesting results (Guennou et al, 2010,Astronomy & Astrophysics Vol 523, page 21, and Clowe et al, 2011 to be submitted). Guennou et al have validated that the necessary accuracy can be achieved with photometric redshifts for our purposes. Clowe et al titled "The DAFT/FADA survey. II. Tomographic weak lensing signal from 10 high redshift clusters," have shown that for the **first time** via this purely geometrical technique, which does not assume a standard rod or candle, that a cosmological constant is **required** for flat cosmologies. The intent of this project is not to produce the best constraint on the value of the dark energy equation of state, w. Rather, this project is to carry out a sustained effort of weak lensing tomography that will naturally feed into the near term Dark Energy Survey (DES) and to provide invaluable mass calibration for that project. These results will greatly advance a key cosmological method which will be applied to the top-rated ground-based project in the Astro2020 decadal survey, LSST. Weak lensing tomography is one of the key science drivers behind LSST. CO-I Clowe is on the weak lensing LSST committee, and senior scientist on this project, at FNAL James Annis, plays a leading role in the DES. This project has built on successful proposals to obtain ground-based imaging for the cluster sample. By 1 Jan, it is anticipated the project will have accumulated complete 5-color photometry on 30 (or about 1/3) of the targeted cluster sample (public webpage for the survey is available at http://cencos.oamp.fr/DAFT/ and has a current summary of the observational status of various clusters). In all, the project has now been awarded the equivalent of over 60
Weak Disposability in Nonparametric Production Analysis with Undesirable Outputs
Kuosmanen, T.K.
Environmental Economics and Natural Resources Group at Wageningen University in The Netherlands Weak disposability of outputs means that firms can abate harmful emissions by decreasing the activity level. Modeling weak disposability in nonparametric production analysis has caused some confusion.
Weakly Idempotent Lattices and Bilattices, Non-Idempotent Plonka Functions
Directory of Open Access Journals (Sweden)
Davidova D. S.
Full Text Available In this paper, we study weakly idempotent lattices with an additional interlaced operation. We characterize interlacity of a weakly idempotent semilattice operation, using the concept of hyperidentity and prove that a weakly idempotent bilattice with an interlaced operation is epimorphic to the superproduct with negation of two equal lattices. In the last part of the paper, we introduce the concepts of a non-idempotent Plonka function and the weakly Plonka sum and extend the main result for algebras with the well known Plonka function to the algebras with the non-idempotent Plonka function. As a consequence, we characterize the hyperidentities of the variety of weakly idempotent lattices, using non-idempotent Plonka functions, weakly Plonka sums and characterization of cardinality of the sets of operations of subdirectly irreducible algebras with hyperidentities of the variety of weakly idempotent lattices. Applications of weakly idempotent bilattices in multi-valued logic is to appear.
Phenomenology of the CKM matrix
International Nuclear Information System (INIS)
Nir, Y.
The way in which an exact determination of the CKM matrix elements tests the standard Model is demonstrated by a two-generation example. The determination of matrix elements from meson semileptonic decays is explained, with an emphasis on the respective reliability of quark level and meson level calculations. The assumptions involved in the use of loop processes are described. Finally, the state of the art of the knowledge of the CKM matrix is presented. 19 refs., 2 figs
On matrix fractional differential equations
Adem Kılıçman; Wasan Ajeel Ahmood
The aim of this article is to study the matrix fractional differential equations and to find the exact solution for system of matrix fractional differential equations in terms of Riemann–Liouville using Laplace transform method and convolution product to the Riemann–Liouville fractional of matrices. Also, we show the theorem of non-homogeneous matrix fractional partial differential equation with some illustrative examples to demonstrate the effectiveness of the new methodology. The main objec...
Qubit state tomography in a superconducting circuit via weak measurements
Qin, Lupei; Xu, Luting; Feng, Wei; Li, Xin-Qi
In this work we present a study on a new scheme for measuring the qubit state in a circuit quantum electrodynamics (QED) system, based on weak measurement and the concept of weak value. To be applicable under generic parameter conditions, our formulation and analysis are carried out for finite-strength weak measurement, and in particular beyond the bad-cavity and weak-response limits. The proposed study is accessible to present state-of-the-art circuit QED experiments.
Weak-interaction contributions to hyperfine splitting and Lamb shift
International Nuclear Information System (INIS)
Eides, M.I.
Weak-interaction contributions to hyperfine splitting and the Lamb shift in hydrogen and muonium are discussed. The problem of sign of the weak-interaction contribution to HFS is clarified, and simple physical arguments that make this sign evident are presented. It is shown that weak-interaction contributions to HFS in hydrogen and muonium have opposite signs. A weak-interaction contribution to the Lamb shift is obtained. copyright 1996 The American Physical Society
Study on the Υ(1S)→B_cM Weak Decays
International Nuclear Information System (INIS)
Huang, Jinshu; Chang, Qin; Wang, Na; Chen, Lili; Sun, Junfeng; Yang, Yueling
Motivated by the prospects of the potential Υ(1S) particle at high-luminosity heavy-flavor experiments, we studied the Υ(1S)→B_cM weak decays, where M = π, ρ, K"("∗"). The nonfactorizable contributions to hadronic matrix elements are taken into consideration with the QCDF approach. It is found that the CKM-favored Υ(1S)→B_cρ decay has branching ratio of O(10"-"1"0), which might be measured promisingly by the future experiments.
Concluding remarks and outlook: Europhysics conference on flavor-mixing in weak interactions
International Nuclear Information System (INIS)
Chau, L.L.
Some comments are offered on the present knowledge of the mixing matrix of Kobayashi and Maskawa and of the dynamics of nonleptonic decay. Also, remarks are made concerning CP violation. Plans for research from 1984 to 1989 are listed briefly. The history of studies on weak interactions is briefly reviewed, and several unanswered questions are stated, such as where are the truth particles, how may they be discovered, what is the mass-generating mechanism for the gauge bosons, how many Z 0 's and W's are there, do neutrinos have mass, and how long do protons live
Matrix transformations and sequence spaces
International Nuclear Information System (INIS)
Nanda, S.
In most cases the most general linear operator from one sequence space into another is actually given by an infinite matrix and therefore the theory of matrix transformations has always been of great interest in the study of sequence spaces. The study of general theory of matrix transformations was motivated by the special results in summability theory. This paper is a review article which gives almost all known results on matrix transformations. This also suggests a number of open problems for further study and will be very useful for research workers. (author)
Multivariate Matrix-Exponential Distributions
DEFF Research Database (Denmark)
Bladt, Mogens; Nielsen, Bo Friis
be written as linear combinations of the elements in the exponential of a matrix. For this reason we shall refer to multivariate distributions with rational Laplace transform as multivariate matrix-exponential distributions (MVME). The marginal distributions of an MVME are univariate matrix......-exponential distributions. We prove a characterization that states that a distribution is an MVME distribution if and only if all non-negative, non-null linear combinations of the coordinates have a univariate matrix-exponential distribution. This theorem is analog to a well-known characterization theorem...
International Nuclear Information System (INIS)
Dorey, Nick; Tong, David; Turner, Carl
We study a U(N) gauged matrix quantum mechanics which, in the large N limit, is closely related to the chiral WZW conformal field theory. This manifests itself in two ways. First, we construct the left-moving Kac-Moody algebra from matrix degrees of freedom. Secondly, we compute the partition function of the matrix model in terms of Schur and Kostka polynomials and show that, in the large N limit, it coincides with the partition function of the WZW model. This same matrix model was recently shown to describe non-Abelian quantum Hall states and the relationship to the WZW model can be understood in this framework.
On Weakly Singular Versions of Discrete Nonlinear Inequalities and Applications
Directory of Open Access Journals (Sweden)
Kelong Cheng
Full Text Available Some new weakly singular versions of discrete nonlinear inequalities are established, which generalize some existing weakly singular inequalities and can be used in the analysis of nonlinear Volterra type difference equations with weakly singular kernels. A few applications to the upper bound and the uniqueness of solutions of nonlinear difference equations are also involved.
quasi hyperrigidity and weak peak points for non-commutative ...
Indian Academy of Sciences (India)
Abstract. In this article, we introduce the notions of weak boundary repre- sentation, quasi hyperrigidity and weak peak points in the non-commutative setting for operator systems in C∗-algebras. An analogue of Saskin's theorem relating quasi hyperrigidity and weak Choquet boundary for particular classes of C∗-algebras is ...
International Nuclear Information System (INIS)
Perdicakis, Michel
Document available in extended abstract form only. In many countries, it is planned that the long life highly radioactive nuclear spent fuel will be stored in deep argillaceous rocks. The sites selected for this purpose are anoxic and satisfy several recommendations as mechanical stability, low permeability and low redox potential. Pyrite (FeS 2 ), iron(II) carbonate, iron(II) bearing clays and organic matter that are present in very small amounts (about 1% w:w) in soils play a major role in their reactivity and are considered today as responsible for the low redox potential values of these sites. In this communication, we describe an electrochemical technique derived from 'Salt matrix voltammetry' and allowing the almost in-situ voltammetric characterization of air-sensitive samples of soils after the only addition of the minimum humidity required for electrolytic conduction. Figure 1 shows the principle of the developed technique. It consists in the entrapment of the clay sample between a graphite working electrode and a silver counter/quasi-reference electrode. The sample was previously humidified by passing a water saturated inert gas through the electrochemical cell. The technique leads to well-defined voltammetric responses of the electro-active components of the clays. Figure 2 shows a typical voltammogram relative to a Callovo-Oxfordian argillite sample from Bure, the French place planned for the underground nuclear waste disposal. During the direct scan, one can clearly distinguish the anodic voltammetric signals for the oxidation of the iron (II) species associated with the clay and the oxidation of pyrite. The reverse scan displays a small cathodic signal for the reduction of iron (III) associated with the clay that demonstrates that the majority of the previously oxidized iron (II) species were transformed into iron (III) oxides reducible at lower potentials. When a second voltammetric cycle is performed, one can notice that the signal for iron (II
Structure and dynamics of weakly bound complexes
International Nuclear Information System (INIS)
Skouteris, D.
The present thesis deals with the spectroscopic and theoretical investigation of weakly bound complexes involving a methane molecule. Studies of these Van der Waals complexes can give valuable information on the relevant intermolecular dynamics and promote the understanding of the interactions between molecules (which can ultimately lead to chemical reactions). Especially interesting are complexes involving molecules of high symmetry (e.g. tetrahedral, such as methane) because of the unusual effects arising from it (selection rules, nuclear Spin statistical weights etc.). The infrared spectrum of the Van der Waals complex between a CH 4 and a N 2 O molecule has been recorded and most of it has been assigned in the region of the N - O stretch (approximately 2225.0 cm -1 ). Despite the fact that this is really a weakly bound complex, it is nevertheless rigid enough so that the standard model for asymmetric top spectra can be applied to it with the usual quantum numbers. From the value of the inertial defect, it turns out that the methane unit is locked in a rigid configuration within the complex rather than freely rotating. The intermolecular distance as well as the tilting angle of the N 2 O linear unit are determined from the rotational constants. The complex itself turns out to have a T - shaped configuration. The infrared spectrum of the Ar - CH 4 complex at the ν 4 (bending) band of methane is also assigned. This is different from the previous one in that the methane unit rotates almost freely Within the complex. As a result, the quantum numbers used to classify rovibrational energy levels include these of the free unit. The concept of 'overall symmetry' is made use of to rationalise selection rules in various sub-bands of the spectrum. Moreover, new terms in the potential anisotropy Hamiltonian are calculated through the use of the overall symmetry concept. These are termed 'mixed anisotropy' terms since they involve both rotational and vibrational degrees of
Ceramic matrix composite article and process of fabricating a ceramic matrix composite article
Cairo, Ronald Robert; DiMascio, Paul Stephen; Parolini, Jason Robert
A ceramic matrix composite article and a process of fabricating a ceramic matrix composite are disclosed. The ceramic matrix composite article includes a matrix distribution pattern formed by a manifold and ceramic matrix composite plies laid up on the matrix distribution pattern, includes the manifold, or a combination thereof. The manifold includes one or more matrix distribution channels operably connected to a delivery interface, the delivery interface configured for providing matrix material to one or more of the ceramic matrix composite plies. The process includes providing the manifold, forming the matrix distribution pattern by transporting the matrix material through the manifold, and contacting the ceramic matrix composite plies with the matrix material.
Characterizing the Atomic Structure in Low Concentrations of Weakly Ordered, Weakly Scattering Materials Using the Pair Distribution Function
Terban, Maxwell W.
Nanoscale structural characterization is critical to understanding the physical underpinnings of properties and behavior in materials with technological applications. The work herein shows how the pair distribution function technique can be applied to x-ray total scattering data for material systems which weakly scatter x-rays, a typically difficult task due to the poor signal-to-noise obtained from the structures of interest. Characterization and structural modeling are demonstrated for a variety of molecular and porous systems, along with the detection and characterization of disordered, minority phases and components. In particular, reliable detection and quantitative analysis are demonstrated for nanocrystals of an active pharmaceutical ingredient suspended in dilute solution down to a concentration of 0.25 wt. %, giving a practical limit of detection for ordered nanoscale phases within a disordered matrix. Further work shows that minority nanocrystalline phases can be detected, fingerprinted, and modeled for mixed crystalline and amorphous systems of small molecules and polymers. The crystallization of amorphous lactose is followed under accelerated aging conditions. Melt quenching is shown to produce a different local structure than spray drying or freeze drying, along with increased resistance to crystallization. The initial phases which form in the spray dried formulation are identified as a mixture of polymorphs different from the final alpha-lactose monohydrate form. Hard domain formation in thermoplastic polyurethanes is also characterized as a function of methylene diphenyl diisocyanate and butanediol component ratio, showing that distinct and different hard phase structures can form and are solved by indexing with structures derived from molecular dynamics relaxation. In both cases, phase fractions can be quantified in the mixed crystalline and amorphous systems by fitting with both standards or structure models. Later chapters, demonstrate pair
Weak convergence and uniform normalization in infinitary rewriting
DEFF Research Database (Denmark)
Simonsen, Jakob Grue
the starkly surprising result that for any orthogonal system with finitely many rules, the system is weakly normalizing under weak convergence if{f} it is strongly normalizing under weak convergence if{f} it is weakly normalizing under strong convergence if{f} it is strongly normalizing under strong...... convergence. As further corollaries, we derive a number of new results for weakly convergent rewriting: Systems with finitely many rules enjoy unique normal forms, and acyclic orthogonal systems are confluent. Our results suggest that it may be possible to recover some of the positive results for strongly...
Pedagogical Review of Quantum Measurement Theory with an Emphasis on Weak Measurements
Directory of Open Access Journals (Sweden)
Bengt E. Y. Svensson
Full Text Available The quantum theory of measurement has been with us since quantum mechanics was invented. It has recently been invigorated, partly due to the increasing interest in quantum information science. In this partly pedagogical review I attempt to give a self-contained overview of non-relativistic quantum theory of measurement expressed in density matrix formalism. I will not dwell on the applications in quantum information theory; it is well covered by several books in that field. The focus is instead on applications to the theory of weak measurement, as developed by Aharonov and collaborators. Their development of weak measurement combined with what they call post-selection - judiciously choosing not only the initial state of a system (pre-selection but also its final state - has received much attention recently. Not the least has it opened up new, fruitful experimental vistas, like novel approaches to amplification. But the approach has also attached to it some air of mystery. I will attempt to demystify it by showing that (almost all results can be derived in a straight-forward way from conventional quantum mechanics. Among other things, I develop the formalism not only to first order but also to second order in the weak interaction responsible for the measurement. I apply it to the so called Leggett-Garg inequalities, also known as Bell inequalities in time. I also give an outline, even if rough, of some of the ingenious experiments that the work by Aharonov and collaborators has inspired. As an application of weak measurement, not related to the approach by Aharonov and collaborators, the formalism also allows me to derive the master equation for the density matrix of an open system in interaction with an environment. An issue that remains in the weak measurement plus post-selection approach is the interpretation of the so called weak value of an observable. Is it a bona fide property of the system considered? I have no definite answer to this
Study of weak interaction with p-p colliding beam
International Nuclear Information System (INIS)
Arafune, Jiro; Sugawara, Hirotaka
Weak interaction in the energy range of TRISTAN project is discussed. The cross-section of production of weak boson in p-p reaction was calculated with the parton model. The observation of weak boson may be possible. The production rate of neutral weak boson was also estimated on the basis of the Weinberg model, and was almost same as that of weak boson. The method of observation of weak boson is suggested. The direct method is the observation of lepton pair due to the decay of neutral weak boson. It is expected that the spectrum of decay products (+ -) in the decay of weak boson shows a characteristic feature, and it shows the existence of weak boson. Weak interaction makes larger contribution in case of large momentum transfer than electromagnetic interaction. When the momentum transfer is larger than 60 GeV/c, the contribution of weak interaction is dominant over the others. Therefore, the experiments at high energy will give informations concerning the relations among the interactions of elementary particles. Possibility of study on the Higgs scalar meson is also discussed. (Kato, T.)
Strategy BMT Al-Ittihad Using Matrix IE, Matrix SWOT 8K, Matrix SPACE and Matrix TWOS
Directory of Open Access Journals (Sweden)
Nofrizal Nofrizal
Full Text Available This research aims to formulate and select BMT Al-Ittihad Rumbai strategy to face the changing of business environment both from internal environment such as organization resources, finance, member and external business such as competitor, economy, politics and others. This research method used Analysis of EFAS, IFAS, IE Matrix, SWOT-8K Matrix, SPACE Matrix and TWOS Matrix. our hope from this research it can assist BMT Al-Ittihad in formulating and selecting strategies for the sustainability of BMT Al-Ittihad in the future. The sample in this research is using purposive sampling technique that is the manager and leader of BMT Al-IttihadRumbaiPekanbaru. The result of this research shows that the position of BMT Al-Ittihad using IE Matrix, SWOT-8K Matrix and SPACE Matrix is in growth position, stabilization and aggressive. The choice of strategy after using TWOS Matrix is market penetration, market development, vertical integration, horizontal integration, and stabilization (careful.
Jairam, Dharmananda; Kiewra, Kenneth A.; Kauffman, Douglas F.; Zhao, Ruomeng
This study investigated how best to study a matrix. Fifty-three participants studied a matrix topically (1 column at a time), categorically (1 row at a time), or in a unified way (all at once). Results revealed that categorical and unified study produced higher: (a) performance on relationship and fact tests, (b) study material satisfaction, and…
Photoinitiated reactions in weakly bonded complexes
International Nuclear Information System (INIS)
Wittig, C.
This paper discusses photoinitiated reactions in weakly bonded binary complexes in which the constituents are only mildly perturbed by the intermolecular bond. Such complexes, with their large zero point excursions, set the stage for events that occur following electronic excitation of one of the constituents. This can take several forms, but in all cases, entrance channel specificity is imposed by the character of the complex as well as the nature of the photoinitiation process. This has enabled us to examine aspects of bimolecular processes: steric effects, chemical branching ratios, and inelastic scattering. Furthermore, monitoring reactions directly in the time domain can reveal mechanisms that cannot be inferred from measurements of nascent product excitations. Consequently, we examined several systems that had been studied previously by our group with product state resolution. With CO 2 /HI, in which reaction occurs via a HOCO intermediate, the rates agree with RRKM predictions. With N 2 O/HI, the gas phase single collision reaction yielding OH + N 2 has been shown to proceed mainly via an HNNO intermediate that undergoes a 1,3-hydrogen shift to the OH + N 2 channel. With complexes, ab initio calculations and high resolution spectroscopic studies of analogous systems suggest that the hydrogen, while highly delocalized, prefers the oxygen to the nitrogen. We observe that OH is produced with a fast risetime (< 250 fs) which can be attributed to either direct oxygen-side attack or rapid HNNO decomposition and/or a termolecular contribution involving the nearby iodine
Relaxion monodromy and the Weak Gravity Conjecture
International Nuclear Information System (INIS)
Ibáñez, L.E.; Montero, M.; Uranga, A.M.; Valenzuela, I.
The recently proposed relaxion models require extremely large trans-Planckian axion excursions as well as a potential explicitly violating the axion shift symmetry. The latter property is however inconsistent with the axion periodicity, which corresponds to a gauged discrete shift symmetry. A way to make things consistent is to use monodromy, i.e. both the axion and the potential parameters transform under the discrete shift symmetry. The structure is better described in terms of a 3-form field C_μ_ν_ρ coupling to the SM Higgs through its field strength F_4. The 4-form also couples linearly to the relaxion, in the Kaloper-Sorbo fashion. The extremely small relaxion-Higgs coupling arises in a see-saw fashion as g≃F_4/f, with f being the axion decay constant. We discuss constraints on this type of constructions from membrane nucleation and the Weak Gravity Conjecture. The latter requires the existence of membranes, whose too fast nucleation could in principle drive the theory out of control, unless the cut-off scale is lowered. This allows to rule out the simplest models with the QCD axion as relaxion candidate on purely theoretical grounds. We also discuss possible avenues to embed this structure into string theory.
Relaxion monodromy and the Weak Gravity Conjecture
Energy Technology Data Exchange (ETDEWEB)
Ibáñez, L.E.; Montero, M. [Departamento de Física Teórica, Facultad de CienciasUniversidad Autónoma de Madrid, 28049 Madrid (Spain); Instituto de Física Teórica IFT-UAM/CSIC,C/ Nicolás Cabrera 13-15, Campus de Cantoblanco, 28049 Madrid (Spain); Uranga, A.M. [Instituto de Física Teórica IFT-UAM/CSIC,C/ Nicolás Cabrera 13-15, Campus de Cantoblanco, 28049 Madrid (Spain); Valenzuela, I. [Max-Planck-Institut fur Physik,Fohringer Ring 6, 80805 Munich (Germany); Institute for Theoretical Physics and Center for Extreme Matter and Emergent Phenomena,Utrecht University,Leuvenlaan 4, 3584 CE Utrecht (Netherlands)
The recently proposed relaxion models require extremely large trans-Planckian axion excursions as well as a potential explicitly violating the axion shift symmetry. The latter property is however inconsistent with the axion periodicity, which corresponds to a gauged discrete shift symmetry. A way to make things consistent is to use monodromy, i.e. both the axion and the potential parameters transform under the discrete shift symmetry. The structure is better described in terms of a 3-form field C{sub μνρ} coupling to the SM Higgs through its field strength F{sub 4}. The 4-form also couples linearly to the relaxion, in the Kaloper-Sorbo fashion. The extremely small relaxion-Higgs coupling arises in a see-saw fashion as g≃F{sub 4}/f, with f being the axion decay constant. We discuss constraints on this type of constructions from membrane nucleation and the Weak Gravity Conjecture. The latter requires the existence of membranes, whose too fast nucleation could in principle drive the theory out of control, unless the cut-off scale is lowered. This allows to rule out the simplest models with the QCD axion as relaxion candidate on purely theoretical grounds. We also discuss possible avenues to embed this structure into string theory.
The weak decay of helium hypernuclei
International Nuclear Information System (INIS)
Athanas, M.J.
A Λ hyperon replaces a neutron in a nucleus to form a hypernucleus via the A X(K - , π - ) Λ A X reaction at 750 MeV/c (Brookhaven Experiment 788). The free Λ decay rates Γ(Λ → pπ - ) and Γ(Λ → nπ 0 ) are diminished due to Pauli blocking; but a non-mesonic decay mode, nucleon stimulated decay NΛ → Nn, is present and is detected via the energetic decay nucleon(s) (∼ 400MeV/c). Measurements of the various hypernuclear decay rates Γ(Λ → pπ - ), Γ(Λ → nπ 0 ) and Γ(Λn → nn) provides insight into the strong modification of the weak interaction such as the baryon-baryon ΔI =1/2 rule. The hypernuclear state is isolated by momentum analysis of (K - , π - ) target reaction. Out-of-beam large volume scintillation detectors and tracking chambers axe used to make particle identification of the hypernuclear decay products by time-of-flight, dE/dx, and range. The kinetic energy of the decay neutrons are measured by time of flight using the large volume 100 element neutron detector system. The hypernuclear lifetime is directly measured using precision scintillator counters and tracking chambers. Measurements of the various decay rates as well as the total lifetime are discussed for Λ 4 He
Weak interactions - formulae, results, and derivations
Energy Technology Data Exchange (ETDEWEB)
Pietschmann, H
The purpose of this book is to provide experimental and theoretical physicists working in the field of weak interactions with a reference work which includes all the formulae and results needed in actual research. The derivation of these formulae is also given in detail for some typical examples to facilitate their use. New developments in unified gauge theories have been included as well as the decay processes of the new particles such as intermediate bosons and tau-lepton. In order to supply the research worker with a convenient working aid, frequently occurring mathematical formulae as well as phase space integrals and the Dirac algebra have been included. Treatment of field operators - also with respect to discrete transformations C, P, T and G - as well as products of invariant functions are provided. Particular emphasis has been placed on the Lagrangian of unified electroweak interactions. The major portion of the work is, of course, devoted to formulae for decay processes and scattering cross-sections. Useful formulae in e/sup +/e/sup -/ reactions and a small dictionary for translations into other forms for the space-time metric are collected in appendices.
Neutron star formation and the weak interaction
International Nuclear Information System (INIS)
Burrows, A.
The only known direct diagnostic of the central event is its neutrino emission. The imprint of the entire internal evolution is stamped on the spectrum, mix of flavors, luminosities, and features of the accompanying neutrino burst. Detection and scrutiny of this neutrino signal will test theories concerning stellar collapse, type II supernovae, and the formation of neutron stars in ways impossible by other means. Despite the fact that an incredible 3x10 53 ergs may be emitted in neutrinos after the initiation of collapse, the very weakness of the neutrino/matter interaction that allows them to penetrate the stellar envelope and escape makes their detection at the Earth very difficult. Though neutrino astronomy is not yet a mature discipline, the physical theories of collapse have progressed to a sufficient degree that specific and detailed predictions can be made about the neutrino emissions that with future detector technology might be tested. The time seems propitious to summarize and review what is known and suspected about the neutrino signature of collapse, the potential for its detection, and how it can be used to test our ideas about the death of massive stars and the birth of neutrino stars. (orig./BBOE)
Forensic bitemark identification: weak foundations, exaggerated claims
Saks, Michael J.; Albright, Thomas; Bohan, Thomas L.; Bierer, Barbara E.; Bowers, C. Michael; Bush, Mary A.; Bush, Peter J.; Casadevall, Arturo; Cole, Simon A.; Denton, M. Bonner; Diamond, Shari Seidman; Dioso-Villa, Rachel; Epstein, Jules; Faigman, David; Faigman, Lisa; Fienberg, Stephen E.; Garrett, Brandon L.; Giannelli, Paul C.; Greely, Henry T.; Imwinkelried, Edward; Jamieson, Allan; Kafadar, Karen; Kassirer, Jerome P.; Koehler, Jonathan 'Jay'; Korn, David; Mnookin, Jennifer; Morrison, Alan B.; Murphy, Erin; Peerwani, Nizam; Peterson, Joseph L.; Risinger, D. Michael; Sensabaugh, George F.; Spiegelman, Clifford; Stern, Hal; Thompson, William C.; Wayman, James L.; Zabell, Sandy; Zumwalt, Ross E.
Abstract Several forensic sciences, especially of the pattern-matching kind, are increasingly seen to lack the scientific foundation needed to justify continuing admission as trial evidence. Indeed, several have been abolished in the recent past. A likely next candidate for elimination is bitemark identification. A number of DNA exonerations have occurred in recent years for individuals convicted based on erroneous bitemark identifications. Intense scientific and legal scrutiny has resulted. An important National Academies review found little scientific support for the field. The Texas Forensic Science Commission recently recommended a moratorium on the admission of bitemark expert testimony. The California Supreme Court has a case before it that could start a national dismantling of forensic odontology. This article describes the (legal) basis for the rise of bitemark identification and the (scientific) basis for its impending fall. The article explains the general logic of forensic identification, the claims of bitemark identification, and reviews relevant empirical research on bitemark identification—highlighting both the lack of research and the lack of support provided by what research does exist. The rise and possible fall of bitemark identification evidence has broader implications—highlighting the weak scientific culture of forensic science and the law's difficulty in evaluating and responding to unreliable and unscientific evidence. PMID:28852538
Blind quantum computing with weak coherent pulses.
Dunjko, Vedran; Kashefi, Elham; Leverrier, Anthony
The universal blind quantum computation (UBQC) protocol [A. Broadbent, J. Fitzsimons, and E. Kashefi, in Proceedings of the 50th Annual IEEE Symposiumon Foundations of Computer Science (IEEE Computer Society, Los Alamitos, CA, USA, 2009), pp. 517-526.] allows a client to perform quantum computation on a remote server. In an ideal setting, perfect privacy is guaranteed if the client is capable of producing specific, randomly chosen single qubit states. While from a theoretical point of view, this may constitute the lowest possible quantum requirement, from a pragmatic point of view, generation of such states to be sent along long distances can never be achieved perfectly. We introduce the concept of ϵ blindness for UBQC, in analogy to the concept of ϵ security developed for other cryptographic protocols, allowing us to characterize the robustness and security properties of the protocol under possible imperfections. We also present a remote blind single qubit preparation protocol with weak coherent pulses for the client to prepare, in a delegated fashion, quantum states arbitrarily close to perfect random single qubit states. This allows us to efficiently achieve ϵ-blind UBQC for any ϵ>0, even if the channel between the client and the server is arbitrarily lossy.
Blind Quantum Computing with Weak Coherent Pulses
Dunjko, Vedran; Kashefi, Elham; Leverrier, Anthony
The universal blind quantum computation (UBQC) protocol [A. Broadbent, J. Fitzsimons, and E. Kashefi, in Proceedings of the 50th Annual IEEE Symposiumon Foundations of Computer Science (IEEE Computer Society, Los Alamitos, CA, USA, 2009), pp. 517-526.] allows a client to perform quantum computation on a remote server. In an ideal setting, perfect privacy is guaranteed if the client is capable of producing specific, randomly chosen single qubit states. While from a theoretical point of view, this may constitute the lowest possible quantum requirement, from a pragmatic point of view, generation of such states to be sent along long distances can never be achieved perfectly. We introduce the concept of ɛ blindness for UBQC, in analogy to the concept of ɛ security developed for other cryptographic protocols, allowing us to characterize the robustness and security properties of the protocol under possible imperfections. We also present a remote blind single qubit preparation protocol with weak coherent pulses for the client to prepare, in a delegated fashion, quantum states arbitrarily close to perfect random single qubit states. This allows us to efficiently achieve ɛ-blind UBQC for any ɛ>0, even if the channel between the client and the server is arbitrarily lossy.
Splitting of the weak hypercharge quantum
Nielsen, H. B.; Brene, N.
The ratio between the weak hypercharge quantum for particles having no coupling to the gauge bosons corresponding to the semi-simple component of the gauge group and the smallest hypercharge quantum for particles that do have such couplings is exceptionally large for the standard model, considering its rank. To compare groups with respect to this property we propose a quantity χ which depends on the rank of the group and the splitting ratio of the hypercharge(s) to be found in the group. The quantity χ has maximal value for the gauge group of the standard model. This suggests that the hypercharge splitting may play an important rôle either in the origin of the gauge symmetry at a fundamental scale or in some kind of selection mechanism at a scale perhaps nearer to the experimental scale. Such a selection mechanism might be what we have called confusion which removes groups with many (so-called generalized) automorphisms. The quantity χ tends to be large for groups with few generalized automorphisms.
Splitting of the weak hypercharge quantum
Energy Technology Data Exchange (ETDEWEB)
Nielsen, H.B.; Brene, N. (Niels Bohr Inst., Copenhagen (Denmark))
The ratio between the weak hypercharge quantum for particles having no coupling to the gauge bosons corresponding to the semi-simple component of the gauge group and the smallest hypercharge quantum for particles that do have such couplings is exceptionally large for the standard model, considering its rank. To compare groups with respect to this property we propose a quantity {chi} which depends on the rank of the group and the splitting ratio of the hypercharge(s) to be found in the group. The quantity {chi} has maximal value for the gauge group of the standard model. This suggests that the hypercharge splitting may play an important role either in the origin of the gauge symmetry at a fundamental scale or in some kind of selection mechanism at a scale perhaps nearer to the experimental scale. Such a selection mechanism might be what we have called confusion which removes groups with many (so-called generalized) automorphisms. The quantity {chi} tends to be large for groups with few generalized automorphisms. (orig.).
Bc meson weak decays and CP violation
International Nuclear Information System (INIS)
Liu, J.; Chao, K.
The form factors for B c transitions are calculated with a relativistic constituent quark model based on the Bethe-Salpeter formalism. The rates for some semileptonic and nonleptonic B c weak decays and CP-violating asymmetries for two-body hardonic B c decays are estimated as well. The calculated widths are compared with those predicted in other quark models of mesons. For the most promising signatures for the discovery of B c : B c →ψlν→(l '+ l '- )lν and B c →ψπ→(l '+ l '- )π (with l ' =e or μ), the combined branching ratios are, respectively, estimated to be 1.06x10 -3 and 4.8a 1 2 x10 -5 for τ B c =0.5 ps and as large as 2.56x10 -3 and 1.15a 1 2 x10 -4 for τ B c =1.2 ps. There are large CP-violating effects in some B c decay modes, and the rates for some of these (e.g., B c →ψD * ,η c D, and η c D * , etc.) are large too. copyright 1997 The American Physical Society
Strong eukaryotic IRESs have weak secondary structure.
Directory of Open Access Journals (Sweden)
Xuhua Xia
Full Text Available BACKGROUND: The objective of this work was to investigate the hypothesis that eukaryotic Internal Ribosome Entry Sites (IRES lack secondary structure and to examine the generality of the hypothesis. METHODOLOGY/PRINCIPAL FINDINGS: IRESs of the yeast and the fruit fly are located in the 5'UTR immediately upstream of the initiation codon. The minimum folding energy (MFE of 60 nt RNA segments immediately upstream of the initiation codons was calculated as a proxy of secondary structure stability. MFE of the reverse complements of these 60 nt segments was also calculated. The relationship between MFE and empirically determined IRES activity was investigated to test the hypothesis that strong IRES activity is associated with weak secondary structure. We show that IRES activity in the yeast and the fruit fly correlates strongly with the structural stability, with highest IRES activity found in RNA segments that exhibit the weakest secondary structure. CONCLUSIONS: We found that a subset of eukaryotic IRESs exhibits very low secondary structure in the 5'-UTR sequences immediately upstream of the initiation codon. The consistency in results between the yeast and the fruit fly suggests a possible shared mechanism of cap-independent translation initiation that relies on an unstructured RNA segment.
Weak lensing in generalized gravity theories
International Nuclear Information System (INIS)
Acquaviva, Viviana; Baccigalupi, Carlo; Perrotta, Francesca
We extend the theory of weak gravitational lensing to cosmologies with generalized gravity, described in the Lagrangian by a generic function depending on the Ricci scalar and a nonminimal coupled scalar field. We work out the generalized Poisson equations relating the dynamics of the fluctuating components to the two gauge-invariant scalar gravitational potentials, fixing the contributions from the modified background expansion and fluctuations. We show how the lensing equation gets modified by the cosmic expansion as well as by the presence of anisotropic stress, which is non-null at the linear level both in scalar-tensor gravity and in theories where the gravitational Lagrangian term features a nonminimal dependence on the Ricci scalar. Starting from the geodesic deviation, we derive the generalized expressions for the shear tensor and projected lensing potential, encoding the spacetime variation of the effective gravitational constant and isolating the contribution of the anisotropic stress, which introduces a correction due to the spatial correlation between the gravitational potentials. Finally, we work out the expressions of the lensing convergence power spectrum as well as the correlation between the lensing potential and the integrated Sachs-Wolfe effect affecting cosmic microwave background total intensity and polarization anisotropies. To illustrate phenomenologically the effects, we work out approximate expressions for the quantities above in extended quintessence scenarios where the scalar field coupled to gravity plays the role of the dark energy
Analysis of trace inorganic anions in weak acid salts by single pump cycling-column-switching ion chromatography.
Huang, Zhongping; Ni, Chengzhu; Zhu, Zhuyi; Pan, Zaifa; Wang, Lili; Zhu, Yan
The application of ion chromatography with the single pump cycling-column-switching technique was described for the analysis of trace inorganic anions in weak acid salts within a single run. Due to the hydrogen ions provided by an anion suppressor electrolyzing water, weak acid anions could be transformed into weak acids, existing as molecules, after passing through the suppressor. Therefore, an anion suppressor and ion-exclusion column were adopted to achieve on-line matrix elimination of weak acid anions with high concentration for the analysis of trace inorganic anions in weak acid salts. A series of standard solutions consisting of target anions of various concentrations from 0.005 to 10 mg/L were analyzed, with correlation coefficients r ≥ 0.9990. The limits of detection were in the range of 0.67 to 1.51 μg/L, based on the signal-to-noise ratio of 3 and a 25 μL injection volume. Relative standard deviations for retention time, peak area, and peak height were all less than 2.01%. A spiking study was performed with satisfactory recoveries between 90.3 and 104.4% for all anions. The chromatographic system was successfully applied to the analysis of trace inorganic anions in five weak acid salts. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
On Characterizing weak defining hyperplanes (weak Facets in DEA with Constant Returns to Scale Technology
Directory of Open Access Journals (Sweden)
Dariush Akbarian
Full Text Available The Production Possibility Set (PPS is defined as a set of inputs and outputs of a system in which inputs can produce outputs. The Production Possibility Set of the Data Envelopment Analysis (DEA model is contain of two types defining hyperplanes (facets; strong and weak efficient facets. In this paper, the problem of finding weak defining hyperplanes of the PPS of the CCR model is dealt with. However, the equation of strong defining hyperplanes of the PPS of the CCR model can be found in this paper. We state and prove some properties relative to our method. To illustrate the applicability of the proposed model, some numerical examples are finally provided. Our algorithm can easily be implemented using existing packages for operation research, such as GAMS.
Bulk metallic glass matrix composites
International Nuclear Information System (INIS)
Choi-Yim, H.; Johnson, W.L.
Composites with a bulk metallic glass matrix were synthesized and characterized. This was made possible by the recent development of bulk metallic glasses that exhibit high resistance to crystallization in the undercooled liquid state. In this letter, experimental methods for processing metallic glass composites are introduced. Three different bulk metallic glass forming alloys were used as the matrix materials. Both ceramics and metals were introduced as reinforcement into the metallic glass. The metallic glass matrix remained amorphous after adding up to a 30 vol% fraction of particles or short wires. X-ray diffraction patterns of the composites show only peaks from the second phase particles superimposed on the broad diffuse maxima from the amorphous phase. Optical micrographs reveal uniformly distributed particles in the matrix. The glass transition of the amorphous matrix and the crystallization behavior of the composites were studied by calorimetric methods. copyright 1997 American Institute of Physics
Machining of Metal Matrix Composites
Machining of Metal Matrix Composites provides the fundamentals and recent advances in the study of machining of metal matrix composites (MMCs). Each chapter is written by an international expert in this important field of research. Machining of Metal Matrix Composites gives the reader information on machining of MMCs with a special emphasis on aluminium matrix composites. Chapter 1 provides the mechanics and modelling of chip formation for traditional machining processes. Chapter 2 is dedicated to surface integrity when machining MMCs. Chapter 3 describes the machinability aspects of MMCs. Chapter 4 contains information on traditional machining processes and Chapter 5 is dedicated to the grinding of MMCs. Chapter 6 describes the dry cutting of MMCs with SiC particulate reinforcement. Finally, Chapter 7 is dedicated to computational methods and optimization in the machining of MMCs. Machining of Metal Matrix Composites can serve as a useful reference for academics, manufacturing and materials researchers, manu...
Quantum mechanics in matrix form
Ludyk, Günter
This book gives an introduction to quantum mechanics with the matrix method. Heisenberg's matrix mechanics is described in detail. The fundamental equations are derived by algebraic methods using matrix calculus. Only a brief description of Schrödinger's wave mechanics is given (in most books exclusively treated), to show their equivalence to Heisenberg's matrix method. In the first part the historical development of Quantum theory by Planck, Bohr and Sommerfeld is sketched, followed by the ideas and methods of Heisenberg, Born and Jordan. Then Pauli's spin and exclusion principles are treated. Pauli's exclusion principle leads to the structure of atoms. Finally, Dirac´s relativistic quantum mechanics is shortly presented. Matrices and matrix equations are today easy to handle when implementing numerical algorithms using standard software as MAPLE and Mathematica.
Phase Structure Of Fuzzy Field Theories And Multi trace Matrix Models
International Nuclear Information System (INIS)
Tekel, J.
We review the interplay of fuzzy field theories and matrix models, with an emphasis on the phase structure of fuzzy scalar field theories. We give a self-contained introduction to these topics and give the details concerning the saddle point approach for the usual single trace and multi trace matrix models. We then review the attempts to explain the phase structure of the fuzzy field theory using a corresponding random matrix ensemble, showing the strength and weaknesses of this approach. We conclude with a list of challenges one needs to overcome and the most interesting open problems one can try to solve. (author)
T -matrix approach to quark-gluon plasma
Liu, Shuai Y. F.; Rapp, Ralf
A self-consistent thermodynamic T -matrix approach is deployed to study the microscopic properties of the quark-gluon plasma (QGP), encompassing both light- and heavy-parton degrees of freedom in a unified framework. The starting point is a relativistic effective Hamiltonian with a universal color force. The input in-medium potential is quantitatively constrained by computing the heavy-quark (HQ) free energy from the static T -matrix and fitting it to pertinent lattice-QCD (lQCD) data. The corresponding T -matrix is then applied to compute the equation of state (EoS) of the QGP in a two-particle irreducible formalism, including the full off-shell properties of the selfconsistent single-parton spectral functions and their two-body interaction. In particular, the skeleton diagram functional is fully resummed to account for emerging bound and scattering states as the critical temperature is approached from above. We find that the solution satisfying three sets of lQCD data (EoS, HQ free energy, and quarkonium correlator ratios) is not unique. As limiting cases we discuss a weakly coupled solution, which features color potentials close to the free energy, relatively sharp quasiparticle spectral functions and weak hadronic resonances near Tc, and a strongly coupled solution with a strong color potential (much larger than the free energy), resulting in broad nonquasiparticle parton spectral functions and strong hadronic resonance states which dominate the EoS when approaching Tc.
Weak lensing galaxy cluster field reconstruction
Jullo, E.; Pires, S.; Jauzac, M.; Kneib, J.-P.
In this paper, we compare three methods to reconstruct galaxy cluster density fields with weak lensing data. The first method called FLens integrates an inpainting concept to invert the shear field with possible gaps, and a multi-scale entropy denoising procedure to remove the noise contained in the final reconstruction, that arises mostly from the random intrinsic shape of the galaxies. The second and third methods are based on a model of the density field made of a multi-scale grid of radial basis functions. In one case, the model parameters are computed with a linear inversion involving a singular value decomposition (SVD). In the other case, the model parameters are estimated using a Bayesian Monte Carlo Markov Chain optimization implemented in the lensing software LENSTOOL. Methods are compared on simulated data with varying galaxy density fields. We pay particular attention to the errors estimated with resampling. We find the multi-scale grid model optimized with Monte Carlo Markov Chain to provide the best results, but at high computational cost, especially when considering resampling. The SVD method is much faster but yields noisy maps, although this can be mitigated with resampling. The FLens method is a good compromise with fast computation, high signal-to-noise ratio reconstruction, but lower resolution maps. All three methods are applied to the MACS J0717+3745 galaxy cluster field, and reveal the filamentary structure discovered in Jauzac et al. We conclude that sensitive priors can help to get high signal-to-noise ratio, and unbiased reconstructions.
Standard and non-standard weak interactions
International Nuclear Information System (INIS)
Leurer, M.
This work consists of independent chapters, all deal with weak interactions. The first chapter deals with left-right symmetric theories. Two main versions of these theories are discussed and compared. In addition, the K - K-bar mixing term is analysed: it has been known for several years now that in a left-right symmetric model there are new contributions to the mixing of kaons. We show that in the most appealing left-right symmetric model - the new contributions add up constructively. Consequently, we may derive reliable bounds on the mass of the right-handed gauge boson and the average mass of the (unavoidable) physical Higgs scalars. We also show that the new contributions are proportional to a new CP violating phase. While all previous treatments of the K - K-bar system were limited to the minimal model, we are able to show that our results hold also in the general case of nonminimal models. The second chapter deals with the possibility that W and Z are composite. Three experimental tests are discussed: (i) Universality -if W is composite then its coupling to the fermions is expected to deviate from universality. Since such deviations were not yet seen -we derive a lower bound on the compositeness scale. (ii) Possible enhancement of the reaction p-bar+p→Z 0 +γ+any - we show that if Z 0 is composite then the cross section for the above process might be considerably enhanced and this effect can be measured at CERN and Fermilab.(iii) The eeγ events of the 1983 run in CERN - we show that in contradiction to suggestions made in several papers, these events may not be explained by a composite-Z decaying through a scalar. In the last chapter we discuss the quark mixing angles
Cosmological information in Gaussianized weak lensing signals
Joachimi, B.; Taylor, A. N.; Kiessling, A.
Gaussianizing the one-point distribution of the weak gravitational lensing convergence has recently been shown to increase the signal-to-noise ratio contained in two-point statistics. We investigate the information on cosmology that can be extracted from the transformed convergence fields. Employing Box-Cox transformations to determine optimal transformations to Gaussianity, we develop analytical models for the transformed power spectrum, including effects of noise and smoothing. We find that optimized Box-Cox transformations perform substantially better than an offset logarithmic transformation in Gaussianizing the convergence, but both yield very similar results for the signal-to-noise ratio. None of the transformations is capable of eliminating correlations of the power spectra between different angular frequencies, which we demonstrate to have a significant impact on the errors in cosmology. Analytic models of the Gaussianized power spectrum yield good fits to the simulations and produce unbiased parameter estimates in the majority of cases, where the exceptions can be traced back to the limitations in modelling the higher order correlations of the original convergence. In the ideal case, without galaxy shape noise, we find an increase in the cumulative signal-to-noise ratio by a factor of 2.6 for angular frequencies up to ℓ= 1500, and a decrease in the area of the confidence region in the Ωm-σ8 plane, measured in terms of q-values, by a factor of 4.4 for the best performing transformation. When adding a realistic level of shape noise, all transformations perform poorly with little decorrelation of angular frequencies, a maximum increase in signal-to-noise ratio of 34 per cent, and even slightly degraded errors on cosmological parameters. We argue that to find Gaussianizing transformations of practical use, it will be necessary to go beyond transformations of the one-point distribution of the convergence, extend the analysis deeper into the non
The weak decay of helium hypernuclei
Energy Technology Data Exchange (ETDEWEB)
Athanas, Michael J. [Carnegie-Mellon Univ., Pittsburgh, PA (United States)
A Λ hyperon replaces a neutron in a nucleus to form a hypernucleus via the AX(K-, π-) $A\\atop{Λ}$X reaction at 750 MeV/c (Brookhaven Experiment 788). The free Λ decay rates Γ(Λ → pπ-) and Γ(Λ → nπ0) are diminished due to Pauli blocking; but a non-mesonic decay mode, nucleon stimulated decay NΛ → Nn, is present and is detected via the energetic decay nucleon(s) (~ 400MeV/c). Measurements of the various hypernuclear decay rates Γ(Λ → pπ-), Γ(Λ → nπ0) and Γ(Λn → nn) provides insight into the strong modification of the weak interaction such as the baryon-baryon ΔI ={1/2} rule. The hypernuclear state is isolated by momentum analysis of (K-, π-) target reaction. Out-of-beam large volume scintillation detectors and tracking chambers axe used to make particle identification of the hypernuclear decay products by time-of-flight, dE/dx, and range. The kinetic energy of the decay neutrons are measured by time of flight using the large volume 100 element neutron detector system. The hypernuclear lifetime is directly measured using precision scintillator counters and tracking chambers. Measurements of the various decay rates as well as the total lifetime are discussed for $4\\atop{Λ}$He.
Inclusive weak decays of charmed mesons
International Nuclear Information System (INIS)
Matthews, C.G.
Inclusive analysis provide a different insight into the understanding of weak decay physics. This thesis experimentally determines inclusive decay predictions of charmed D mesons. Exclusive decay predictions are also used from a variety of theoretical models to make predictions about inclusive properties. Both experimental and theoretical realms benefit from the new techniques presented in this thesis. Inclusive properties derived are the multiplicity distributions, average multiplicities and inclusive branching ratios of charged particles, charged and neutral kaons, and charged pions. The center-of-mass momentum spectra of charged and neutral kaons are also obtained. Additionally, in the theoretical realm only, the inclusive properties of neutral pions, and the center-of-mass momentum spectra of charged and neutral pions are determined. The experimental analysis, which uses data from the mark II experiment at the Stanford Linear Accelerator Center, employs an unfold technique utilizing fold matrices to obtain the charged particle and kaon properties. A new enhanced unfold technique involving fold tensors obtains the first-ever results for the inclusive charged pion properties. The average strange quark contents and the average charged lepton multiplicities of the D + , D 0 and D + 8 are also presented. In the theoretical analysis, the exclusive decay mode predictions from the factorization model for Bauer, Stech and Wirbel; the quark diagram scheme of Chau and Cheng; and the QCD sum rules model of Block and Shifman are processed to determine inclusive predictions will lead to a better understanding of the model. The thesis also derives inclusive predictions from the D meson exclusive branching ratios compiled by the Particle Data Group
Weak values in a classical theory with an epistemic restriction
International Nuclear Information System (INIS)
Karanjai, Angela; Cavalcanti, Eric G; Bartlett, Stephen D; Rudolph, Terry
Weak measurement of a quantum system followed by postselection based on a subsequent strong measurement gives rise to a quantity called the weak value: a complex number for which the interpretation has long been debated. We analyse the procedure of weak measurement and postselection, and the interpretation of the associated weak value, using a theory of classical mechanics supplemented by an epistemic restriction that is known to be operationally equivalent to a subtheory of quantum mechanics. Both the real and imaginary components of the weak value appear as phase space displacements in the postselected expectation values of the measurement device's position and momentum distributions, and we recover the same displacements as in the quantum case by studying the corresponding evolution in our theory of classical mechanics with an epistemic restriction. By using this epistemically restricted theory, we gain insight into the appearance of the weak value as a result of the statistical effects of post selection, and this provides us with an operational interpretation of the weak value, both its real and imaginary parts. We find that the imaginary part of the weak value is a measure of how much postselection biases the mean phase space distribution for a given amount of measurement disturbance. All such biases proportional to the imaginary part of the weak value vanish in the limit where disturbance due to measurement goes to zero. Our analysis also offers intuitive insight into how measurement disturbance can be minimized and the limits of weak measurement. (paper)
Effects of quenching and partial quenching on QCD penguin matrix elements
Golterman, Maarten; Pallante, Elisabetta
We point out that chiral transformation properties of penguin operators change in the transition from unquenched to (partially) quenched QCD. The way in which this affects the lattice determination of weak matrix elements can be understood in the framework of (partially) quenched chiral perturbation
Containment Code Validation Matrix
International Nuclear Information System (INIS)
Chin, Yu-Shan; Mathew, P.M.; Glowa, Glenn; Dickson, Ray; Liang, Zhe; Leitch, Brian; Barber, Duncan; Vasic, Aleks; Bentaib, Ahmed; Journeau, Christophe; Malet, Jeanne; Studer, Etienne; Meynet, Nicolas; Piluso, Pascal; Gelain, Thomas; Michielsen, Nathalie; Peillon, Samuel; Porcheron, Emmanuel; Albiol, Thierry; Clement, Bernard; Sonnenkalb, Martin; Klein-Hessling, Walter; Arndt, Siegfried; Weber, Gunter; Yanez, Jorge; Kotchourko, Alexei; Kuznetsov, Mike; Sangiorgi, Marco; Fontanet, Joan; Herranz, Luis; Garcia De La Rua, Carmen; Santiago, Aleza Enciso; Andreani, Michele; Paladino, Domenico; Dreier, Joerg; Lee, Richard; Amri, Abdallah
The Committee on the Safety of Nuclear Installations (CSNI) formed the CCVM (Containment Code Validation Matrix) task group in 2002. The objective of this group was to define a basic set of available experiments for code validation, covering the range of containment (ex-vessel) phenomena expected in the course of light and heavy water reactor design basis accidents and beyond design basis accidents/severe accidents. It was to consider phenomena relevant to pressurised heavy water reactor (PHWR), pressurised water reactor (PWR) and boiling water reactor (BWR) designs of Western origin as well as of Eastern European VVER types. This work would complement the two existing CSNI validation matrices for thermal hydraulic code validation (NEA/CSNI/R(1993)14) and In-vessel core degradation (NEA/CSNI/R(2001)21). The report initially provides a brief overview of the main features of a PWR, BWR, CANDU and VVER reactors. It also provides an overview of the ex-vessel corium retention (core catcher). It then provides a general overview of the accident progression for light water and heavy water reactors. The main focus is to capture most of the phenomena and safety systems employed in these reactor types and to highlight the differences. This CCVM contains a description of 127 phenomena, broken down into 6 categories: - Containment Thermal-hydraulics Phenomena; - Hydrogen Behaviour (Combustion, Mitigation and Generation) Phenomena; - Aerosol and Fission Product Behaviour Phenomena; - Iodine Chemistry Phenomena; - Core Melt Distribution and Behaviour in Containment Phenomena; - Systems Phenomena. A synopsis is provided for each phenomenon, including a description, references for further information, significance for DBA and SA/BDBA and a list of experiments that may be used for code validation. The report identified 213 experiments, broken down into the same six categories (as done for the phenomena). An experiment synopsis is provided for each test. Along with a test description
Oehlmann, Dietmar; Ohlmann, Odile M.; Danzebrink, Hans U.
perform this exchange, as a matrix, understood as source, of new ideas.
Measuring methods of matrix diffusion
International Nuclear Information System (INIS)
Muurinen, A.; Valkiainen, M.
In Finland the spent nuclear fuel is planned to be disposed of at large depths in crystalline bedrock. The radionuclides which are dissolved in the groundwater may be able to diffuse into the micropores of the porous rock matrix and thus be withdrawn from the flowing water in the fractures. This phenomenon is called matrix diffusion. A review over matrix diffusion is presented in the study. The main interest is directed to the diffusion of non-sorbing species. The review covers diffusion experiments and measurements of porosity, pore size, specific surface area and water permeability
Maximal quantum Fisher information matrix
International Nuclear Information System (INIS)
Chen, Yu; Yuan, Haidong
We study the existence of the maximal quantum Fisher information matrix in the multi-parameter quantum estimation, which bounds the ultimate precision limit. We show that when the maximal quantum Fisher information matrix exists, it can be directly obtained from the underlying dynamics. Examples are then provided to demonstrate the usefulness of the maximal quantum Fisher information matrix by deriving various trade-off relations in multi-parameter quantum estimation and obtaining the bounds for the scalings of the precision limit. (paper)
Proximal Limb Weakness Reverting After CSF Diversion In Intracranial Hypertension
Directory of Open Access Journals (Sweden)
Sinha S
Full Text Available We report about two young girls who developed progressive visual failure secondary to increased intracranial pressure and had significant proximal muscle weakness of limbs. Patients with elevated intracranial pressure (ICP may present with "false localizing signs", besides having headache, vomiting and papilledema. Radicular pain as a manifestation of raised ICP is rare and motor weakness attributable to polyradiculopathy is exceptional. Two patients with increased intracranial pressure without lateralizing signs′ had singnificant muscle weakness. Clinical evaluation and laboratory tests did not disclose any other cause for weakness. Following theco-peritoneal shunt, in both patients, there was variable recovery of vision but the proximal weakness and symptoms of elevated ICP improved rapidly. Recognition of this uncommon manifestation of raised ICP may obviate the need for unnecessary investigation and reduce morbidity due to weakness by CSF diversion procedure.
On Hardy's paradox, weak measurements, and multitasking diagrams
International Nuclear Information System (INIS)
Meglicki, Zdzislaw
We discuss Hardy's paradox and weak measurements by using multitasking diagrams, which are introduced to illustrate the progress of quantum probabilities through the double interferometer system. We explain how Hardy's paradox is avoided and elaborate on the outcome of weak measurements in this context. -- Highlights: → Hardy's paradox explained and eliminated. → Weak measurements: what is really measured? → Multitasking diagrams: introduced and used to discuss quantum mechanical processes.
Information flow between weakly interacting lattices of coupled maps
Energy Technology Data Exchange (ETDEWEB)
Dobyns, York [PEAR, Princeton University, Princeton, NJ 08544-5263 (United States); Atmanspacher, Harald [Institut fuer Grenzgebiete der Psychologie und Psychohygiene, Wilhelmstr. 3a, 79098 Freiburg (Germany)]. E-mail: email@example.com
Weakly interacting lattices of coupled maps can be modeled as ordinary coupled map lattices separated from each other by boundary regions with small coupling parameters. We demonstrate that such weakly interacting lattices can nevertheless have unexpected and striking effects on each other. Under specific conditions, particular stability properties of the lattices are significantly influenced by their weak mutual interaction. This observation is tantamount to an efficacious information flow across the boundary.
Information flow between weakly interacting lattices of coupled maps
International Nuclear Information System (INIS)
Dobyns, York; Atmanspacher, Harald
Weakly interacting lattices of coupled maps can be modeled as ordinary coupled map lattices separated from each other by boundary regions with small coupling parameters. We demonstrate that such weakly interacting lattices can nevertheless have unexpected and striking effects on each other. Under specific conditions, particular stability properties of the lattices are significantly influenced by their weak mutual interaction. This observation is tantamount to an efficacious information flow across the boundary
Simulation of weak and strong Langmuir collapse regimes
International Nuclear Information System (INIS)
Hadzievski, L.R.; Skoric, M.M.; Kono, M.; Sato, T.
In order to check the validity of the self-similar solutions and the existence of weak and strong collapse regimes, direct two dimensional simulation of the time evolution of a Langmuir soliton instability is performed. Simulation is based on the Zakharov model of strong Langmuir turbulence in a weakly magnetized plasma accounting for the full ion dynamics. For parameters considered, agreement with self-similar dynamics of the weak collapse type is found with no evidence of the strong Langmuir collapse. (author)
Matrix product operators, matrix product states, and ab initio density matrix renormalization group algorithms
Chan, Garnet Kin-Lic; Keselman, Anna; Nakatani, Naoki; Li, Zhendong; White, Steven R.
Current descriptions of the ab initio density matrix renormalization group (DMRG) algorithm use two superficially different languages: an older language of the renormalization group and renormalized operators, and a more recent language of matrix product states and matrix product operators. The same algorithm can appear dramatically different when written in the two different vocabularies. In this work, we carefully describe the translation between the two languages in several contexts. First, we describe how to efficiently implement the ab initio DMRG sweep using a matrix product operator based code, and the equivalence to the original renormalized operator implementation. Next we describe how to implement the general matrix product operator/matrix product state algebra within a pure renormalized operator-based DMRG code. Finally, we discuss two improvements of the ab initio DMRG sweep algorithm motivated by matrix product operator language: Hamiltonian compression, and a sum over operators representation that allows for perfect computational parallelism. The connections and correspondences described here serve to link the future developments with the past and are important in the efficient implementation of continuing advances in ab initio DMRG and related algorithms.
A Sparsity-Promoted Method Based on Majorization-Minimization for Weak Fault Feature Enhancement.
Ren, Bangyue; Hao, Yansong; Wang, Huaqing; Song, Liuyang; Tang, Gang; Yuan, Hongfang
Fault transient impulses induced by faulty components in rotating machinery usually contain substantial interference. Fault features are comparatively weak in the initial fault stage, which renders fault diagnosis more difficult. In this case, a sparse representation method based on the Majorzation-Minimization (MM) algorithm is proposed to enhance weak fault features and extract the features from strong background noise. However, the traditional MM algorithm suffers from two issues, which are the choice of sparse basis and complicated calculations. To address these challenges, a modified MM algorithm is proposed in which a sparse optimization objective function is designed firstly. Inspired by the Basis Pursuit (BP) model, the optimization function integrates an impulsive feature-preserving factor and a penalty function factor. Second, a modified Majorization iterative method is applied to address the convex optimization problem of the designed function. A series of sparse coefficients can be achieved through iterating, which only contain transient components. It is noteworthy that there is no need to select the sparse basis in the proposed iterative method because it is fixed as a unit matrix. Then the reconstruction step is omitted, which can significantly increase detection efficiency. Eventually, envelope analysis of the sparse coefficients is performed to extract weak fault features. Simulated and experimental signals including bearings and gearboxes are employed to validate the effectiveness of the proposed method. In addition, comparisons are made to prove that the proposed method outperforms the traditional MM algorithm in terms of detection results and efficiency.
National Oceanic and Atmospheric Administration, Department of Commerce — This data set was taken from CRD 08-18 at the NEFSC. Specifically, the Gulf of Maine diet matrix was developed for the EMAX exercise described in that center...
On matrix fractional differential equations
Directory of Open Access Journals (Sweden)
Adem Kılıçman
Full Text Available The aim of this article is to study the matrix fractional differential equations and to find the exact solution for system of matrix fractional differential equations in terms of Riemann–Liouville using Laplace transform method and convolution product to the Riemann–Liouville fractional of matrices. Also, we show the theorem of non-homogeneous matrix fractional partial differential equation with some illustrative examples to demonstrate the effectiveness of the new methodology. The main objective of this article is to discuss the Laplace transform method based on operational matrices of fractional derivatives for solving several kinds of linear fractional differential equations. Moreover, we present the operational matrices of fractional derivatives with Laplace transform in many applications of various engineering systems as control system. We present the analytical technique for solving fractional-order, multi-term fractional differential equation. In other words, we propose an efficient algorithm for solving fractional matrix equation.
Electromagnetic matrix elements in baryons
International Nuclear Information System (INIS)
Lipkin, H.J.; Moinester, M.A.
Some simple symmetry relations between matrix elements of electromagnetic operators are investigated. The implications are discussed for experiments to study hyperon radiative transitions and polarizabilities and form factors. (orig.)
International Nuclear Information System (INIS)
Descouvemont, P; Baye, D
The different facets of the R-matrix method are presented pedagogically in a general framework. Two variants have been developed over the years: (i) The 'calculable' R-matrix method is a calculational tool to derive scattering properties from the Schroedinger equation in a large variety of physical problems. It was developed rather independently in atomic and nuclear physics with too little mutual influence. (ii) The 'phenomenological' R-matrix method is a technique to parametrize various types of cross sections. It was mainly (or uniquely) used in nuclear physics. Both directions are explained by starting from the simple problem of scattering by a potential. They are illustrated by simple examples in nuclear and atomic physics. In addition to elastic scattering, the R-matrix formalism is applied to inelastic and radiative-capture reactions. We also present more recent and more ambitious applications of the theory in nuclear physics.
Random matrix improved subspace clustering
Couillet, Romain; Kammoun, Abla
This article introduces a spectral method for statistical subspace clustering. The method is built upon standard kernel spectral clustering techniques, however carefully tuned by theoretical understanding arising from random matrix findings. We show
Weak value distributions for spin 1/2
Berry, M. V.; Dennis, M. R.; McRoberts, B.; Shukla, P.
The simplest weak measurement is of a component of spin 1/2. For this observable, the probability distributions of the real and imaginary parts of the weak value, and their joint probability distribution, are calculated exactly for pre- and postselected states uniformly distributed over the surface of the Poincaré-Bloch sphere. The superweak probability, that the real part of the weak value lies outside the spectral range, is 1/3. This case, with just two eigenvalues, complements our previous calculation (Berry and Shukla 2010 J. Phys. A: Math. Theor. 43 354024) of the universal form of the weak value probability distribution for an operator with many eigenvalues.
Weak value distributions for spin 1/2
International Nuclear Information System (INIS)
Berry, M V; Dennis, M R; McRoberts, B; Shukla, P
The simplest weak measurement is of a component of spin 1/2. For this observable, the probability distributions of the real and imaginary parts of the weak value, and their joint probability distribution, are calculated exactly for pre- and postselected states uniformly distributed over the surface of the Poincare-Bloch sphere. The superweak probability, that the real part of the weak value lies outside the spectral range, is 1/3. This case, with just two eigenvalues, complements our previous calculation (Berry and Shukla 2010 J. Phys. A: Math. Theor. 43 354024) of the universal form of the weak value probability distribution for an operator with many eigenvalues.
Matrix Effects in XRF Measurements
International Nuclear Information System (INIS)
Kandil, A.T.; Gabr, N.A.; El-Aryan, S.M.
This research treats the matrix effect on XRF measurements. The problem is treated by preparing general oxide program, which contains many samples that represent all materials in cement factories, then by using T rail Lachance m ethod to correct errors of matrix effect. This work compares the effect of using lithium tetraborate or sodium tetraborate as a fluxing agent in terms of accuracy and economic cost
Matrix analysis of electrical machinery
Hancock, N N
Matrix Analysis of Electrical Machinery, Second Edition is a 14-chapter edition that covers the systematic analysis of electrical machinery performance. This edition discusses the principles of various mathematical operations and their application to electrical machinery performance calculations. The introductory chapters deal with the matrix representation of algebraic equations and their application to static electrical networks. The following chapters describe the fundamentals of different transformers and rotating machines and present torque analysis in terms of the currents based on the p
Staggered chiral random matrix theory
International Nuclear Information System (INIS)
Osborn, James C.
We present a random matrix theory for the staggered lattice QCD Dirac operator. The staggered random matrix theory is equivalent to the zero-momentum limit of the staggered chiral Lagrangian and includes all taste breaking terms at their leading order. This is an extension of previous work which only included some of the taste breaking terms. We will also present some results for the taste breaking contributions to the partition function and the Dirac eigenvalues.
Renormalization-group analysis of the Kobayashi-Maskawa matrix
International Nuclear Information System (INIS)
Babu, K.S.
The one-loop renormalization-group equations for the quark mixing (Kobayashi-Maskawa) matrix V are derived, independent of one's weak interaction basis, in the standard model as well as in its two Higgs and supersymmetric extensions, and their numerical solutions are presented. While the mixing angles vertical strokeV ub vertical stroke, vertical strokeV cb vertical stroke, vertical strokeV td vertical stroke and the phase-invariant measure of CP nonconservation J all vary slowly with momentum, in the standard model they are predicted to increase in clear contrast to the two Higgs and supersymmetric extensions where they decrease with momentum. (orig.)
Glueball Spectrum and Matrix Elements on Anisotropic Lattices
Energy Technology Data Exchange (ETDEWEB)
Y. Chen; A. Alexandru; S.J. Dong; T. Draper; I. Horvath; F.X. Lee; K.F. Liu; N. Mathur; C. Morningstar; M. Peardon; S. Tamhankar; B.L. Young; J.B. Zhang
The glueball-to-vacuum matrix elements of local gluonic operators in scalar, tensor, and pseudoscalar channels are investigated numerically on several anisotropic lattices with the spatial lattice spacing ranging from 0.1fm - 0.2fm. These matrix elements are needed to predict the glueball branching ratios in J/{psi} radiative decays which will help identify the glueball states in experiments. Two types of improved local gluonic operators are constructed for a self-consistent check and the finite volume effects are studied. We find that lattice spacing dependence of our results is very weak and the continuum limits are reliably extrapolated, as a result of improvement of the lattice gauge action and local operators. We also give updated glueball masses with various quantum numbers.
International Nuclear Information System (INIS)
Furlan, E.; Forrest, W. J.; Manoj, P.; Kim, K. H.; Watson, Dan M.; Sargent, B. A.
We use Spitzer data to infer that the small infrared excess of V819 Tau, a weak-lined T Tauri star in Taurus, is real and not attributable to a 'companion' 10'' to the south. We do not confirm the mid-infrared excess in HBC 427 and V410 X-ray 3, which are also non-accreting T Tauri stars in the same region; instead, for the former object, the excess arises from a red companion 9'' to the east. A single-temperature blackbody fit to the continuum excess of V819 Tau implies a dust temperature of 143 K; however, a better fit is achieved when the weak 10 and 20 μm silicate emission features are also included. We infer a disk of sub-μm silicate grains between about 1 AU and several 100 AU with a constant surface density distribution. The mid-infrared excess of V819 Tau can be successfully modeled with dust composed mostly of small amorphous olivine grains at a temperature of 85 K, and most of the excess emission is optically thin. The disk could still be primordial, but gas-poor and therefore short-lived, or already at the debris disk stage, which would make it one of the youngest debris disk systems known.
Carbon fibre reinforced copper matrix composites: processing routes and properties
Energy Technology Data Exchange (ETDEWEB)
Le Petitcorps, Y. [Bordeaux-1 Univ., 33 - Pessac (France). ICMCB; Poueylaud, J.M. [Bordeaux-1 Univ., 33 - Pessac (France). ICMCB; Albingre, L. [Bordeaux-1 Univ., 33 - Pessac (France). ICMCB; Berdeu, B. [L`Electrolyse, 33 - Latresne (France); Lobstein, P. [L`Electrolyse, 33 - Latresne (France); Silvain, J.F. [Bordeaux-1 Univ., 33 - Pessac (France). ICMCB
Copper matrix composites are of interest for applications in the electronic field which requires materials with high thermal conductivity properties. The use of carbon fibres can (1) decrease the density and the coefficient of thermal expansion of the material and (2) increase the stiffness and strength to rupture of the resulting composite. In order to produce cheap materials, chemical plating and uniaxial hot pressing processing routes were chosen. 1D-C{sub (P55Thornel)} / Cu prepregs were hot pressed in an argon atmosphere at 750 C during 30 min. The volume fraction of the fibres within the composite was in the range of 10-35%. Physical (density and thermal expansion coefficient) and thermal conductivity properties of the composite were in good agreement with the predictions. However this material exhibits very poor mechanical properties (Young`s modulus and tensile strength). Scanning electron microscopy (SEM) observations of the surfaces of ruptures have shown that (1) a very weak bonding between the graphite fibres and the copper matrix was formed and (2) the rupture of the composite was initiated in the matrix at the copper grain boundaries. In order to overcome these two difficulties, the carbon fibres were pre-coated with a thin layer (100 nm) of cobalt. The aim of the cobalt was to react with the carbon to form carbide compounds and as a consequence to increase the bonding between the metal and the fibre. The tensile properties ({sigma}{sub c}{sup R} and E{sub c}) of this composite were then increased by 50% in comparison with the former material; however the strain to rupture was still too weak ({epsilon}{sub c}{sup R} = 0.5%). In order to explain the role of each constituents, X-ray profiles and TEM analyses were done at the fibre/matrix interface and at the grain boundaries. Some modifications of the chemical plating steps were done to improve the purity of the copper. (orig.)
Non-Hermitian Extensions of Wishart Random Matrix Ensembles
International Nuclear Information System (INIS)
Akemann, G.
We briefly review the solution of three ensembles of non-Hermitian random matrices generalizing the Wishart-Laguerre (also called chiral) ensembles. These generalizations are realized as Gaussian two-matrix models, where the complex eigenvalues of the product of the two independent rectangular matrices are sought, with the matrix elements of both matrices being either real, complex or quaternion real. We also present the more general case depending on a non-Hermiticity parameter, that allows us to interpolate between the corresponding three Hermitian Wishart ensembles with real eigenvalues and the maximally non-Hermitian case. All three symmetry classes are explicitly solved for finite matrix size N x M for all complex eigenvalue correlations functions (and real or mixed correlations for real matrix elements). These are given in terms of the corresponding kernels built from orthogonal or skew-orthogonal Laguerre polynomials in the complex plane. We then present the corresponding three Bessel kernels in the complex plane in the microscopic large-N scaling limit at the origin, both at weak and strong non-Hermiticity with M - N ≥ 0 fixed. (author)
Biological effects due to weak magnetic fields on plants
Belyavskaya, N.
In the evolution process, living organisms have experienced the action of the Earth's magnetic field (MF) that is a natural component of our environment. It is known that a galactic MF induction does not exceed 0.1 nT, since investigations of weak magnetic field (WMF) effects on biological systems have attracted attention of biologists due to planning long-term space flights to other planets where the magnetizing force is near 10-5 Oe. However, the role of WMF and its influence on organisms' functioning are still insufficiently investigated. A large number of experiments with seedlings of different plant species placed in WMF has found that the growth of their primary roots is inhibited during the early terms of germination in comparison with control. The proliferation activity and cell reproduction are reduced in meristem of plant roots under WMF application. The prolongation of total cell reproductive cycle is registered due to the expansion of G phase in1 different plant species as well as of G phase in flax and lentil roots along with2 relative stability of time parameters of other phases of cell cycle. In plant cells exposed to WMF, the decrease in functional activity of genome at early prereplicate period is shown. WMF causes the intensification in the processes of proteins' synthesis and break-up in plant roots. Qualitative and quantitative changes in protein spectrum in growing and differentiated cells of plant roots exposed to WMF are revealed. At ultrastructural level, there are observed such ultrastructural peculiarities as changes in distribution of condensed chromatin and nucleolus compactization in nuclei, noticeable accumulation of lipid bodies, development of a lytic compartment (vacuoles, cytosegresomes and paramural bodies), and reduction of phytoferritin in plastids in meristem cells of pea roots exposed to WMF. Mitochondria are the most sensitive organelle to WMF application: their size and relative volume in cells increase, matrix is electron
EISPACK, Subroutines for Eigenvalues, Eigenvectors, Matrix Operations
International Nuclear Information System (INIS)
Garbow, Burton S.; Cline, A.K.; Meyering, J.
1 - Description of problem or function: EISPACK3 is a collection of 75 FORTRAN subroutines, both single- and double-precision, that compute the eigenvalues and eigenvectors of nine classes of matrices. The package can determine the Eigen-system of complex general, complex Hermitian, real general, real symmetric, real symmetric band, real symmetric tridiagonal, special real tridiagonal, generalized real, and generalized real symmetric matrices. In addition, there are two routines which use the singular value decomposition to solve certain least squares problem. The individual subroutines are - Identification/Description: BAKVEC: Back transform vectors of matrix formed by FIGI; BALANC: Balance a real general matrix; BALBAK: Back transform vectors of matrix formed by BALANC; BANDR: Reduce sym. band matrix to sym. tridiag. matrix; BANDV: Find some vectors of sym. band matrix; BISECT: Find some values of sym. tridiag. matrix; BQR: Find some values of sym. band matrix; CBABK2: Back transform vectors of matrix formed by CBAL; CBAL: Balance a complex general matrix; CDIV: Perform division of two complex quantities; CG: Driver subroutine for a complex general matrix; CH: Driver subroutine for a complex Hermitian matrix; CINVIT: Find some vectors of complex Hess. matrix; COMBAK: Back transform vectors of matrix formed by COMHES; COMHES: Reduce complex matrix to complex Hess. (elementary); COMLR: Find all values of complex Hess. matrix (LR); COMLR2: Find all values/vectors of cmplx Hess. matrix (LR); CCMQR: Find all values of complex Hessenberg matrix (QR); COMQR2: Find all values/vectors of cmplx Hess. matrix (QR); CORTB: Back transform vectors of matrix formed by CORTH; CORTH: Reduce complex matrix to complex Hess. (unitary); CSROOT: Find square root of complex quantity; ELMBAK: Back transform vectors of matrix formed by ELMHES; ELMHES: Reduce real matrix to real Hess. (elementary); ELTRAN: Accumulate transformations from ELMHES (for HQR2); EPSLON: Estimate unit roundoff
Analysis of Strengths, Weaknesses, Opportunities, and Threats as a Tool for Translating Evidence into Individualized Medical Strategies (I-SWOT).
von Kodolitsch, Yskert; Bernhardt, Alexander M; Robinson, Peter N; Kölbel, Tilo; Reichenspurner, Hermann; Debus, Sebastian; Detter, Christian
It is the physicians' task to translate evidence and guidelines into medical strategies for individual patients. Until today, however, there is no formal tool that is instrumental to perform this translation. We introduce the analysis of strengths (S) and weaknesses (W) related to therapy with opportunities (O) and threats (T) related to individual patients as a tool to establish an individualized (I) medical strategy (I-SWOT). The I-SWOT matrix identifies four fundamental types of strategy. These comprise "SO" maximizing strengths and opportunities, "WT" minimizing weaknesses and threats, "WO" minimizing weaknesses and maximizing opportunities, and "ST" maximizing strengths and minimizing threats. Each distinct type of strategy may be considered for individualized medical strategies. We describe four steps of I-SWOT to establish an individualized medical strategy to treat aortic disease. In the first step, we define the goal of therapy and identify all evidence-based therapeutic options. In a second step, we assess strengths and weaknesses of each therapeutic option in a SW matrix form. In a third step, we assess opportunities and threats related to the individual patient, and in a final step, we use the I-SWOT matrix to establish an individualized medical strategy through matching "SW" with "OT". As an example we present two 30-year-old patients with Marfan syndrome with identical medical history and aortic pathology. As a result of I-SWOT analysis of their individual opportunities and threats, we identified two distinct medical strategies in these patients. I-SWOT is a formal but easy to use tool to translate medical evidence into individualized medical strategies.
Weak interactions, quark masses and spontaneous violation of parity
International Nuclear Information System (INIS)
Kingsley, R.L.
A six quark model is discussed for the weak interactions of hadrons in which parity is violated spontaneously in an SU(2) x U(1) gauge theory. Quarks with very small masses are required and their weak interactions approximate those of the Weinberg-Salam model. Suppression of strangeness-changing neutral currents requires at least seven quarks. (author)
Covenants with Weak Swords: ISO 14001 and Facilities' Environmental Performance
Potoski, Matthew; Prakash, Aseem
Voluntary environmental programs are codes of progressive environmental conduct that firms pledge to adopt. This paper investigates whether ISO 14001, a voluntary program with a weak sword--a weak monitoring and sanctioning mechanism--can mitigate shirking and improve participants' environmental performance. Sponsored by the International…
Measuring Workload Weak Resilience Signals at a Rail Control Post
Siegel, A.W.; Schraagen, J.M.C.
OCCUPATIONAL APPLICATIONS This article describes an observational study at a rail control post to measure workload weak resilience signals. A weak resilience signal indicates a possible degradation of a system's resilience, which is defined as the ability of a complex socio-technical system to cope
Polarization phenomena in isobar production by a weak neutral current
International Nuclear Information System (INIS)
Esajbegyan, S.V.; Matinyan, S.G.
Polarization phenomen connected with weak neutral currents producing the isobar in the lepton-nucleon scattering are considered. It is shown that measurement of the angular distribution of π mesons so as to detect also the longitudinally polarized decay nucleon can provide usefull information about validity of various models including a weak neutral current
Proposed ripplon induced weak localization of electrons over liquid helium
International Nuclear Information System (INIS)
Dahm, A.J.
Ripplon induced weak localization is proposed for electrons on a liquid helium surface. Ripplon scattering is quasi-elastic, the ripplon are quasi-static relative to the electron velocity, and the relative change in occupation number of the ripplon state in a scattering event is small. Conditions for the observation of ripplon induced weak localization are calculated
Bunched soliton states in weakly coupled sine-Gordon systems
DEFF Research Database (Denmark)
Grønbech-Jensen, N.; Samuelsen, Mogens Rugholm; Lomdahl, P. S.
The interaction between solitons of two weakly coupled sine-Gordon systems is considered. In particular, the stability of bunched states is investigated, and perturbation results are compared with numerical results.......The interaction between solitons of two weakly coupled sine-Gordon systems is considered. In particular, the stability of bunched states is investigated, and perturbation results are compared with numerical results....
Weak decay amplitudes in large N/sub c/ QCD
International Nuclear Information System (INIS)
Bardeen, W.A.
A systematic analysis of nonleptonic decay amplitudes is presented using the large N/sub c/ expansion of quantum chromodynamics. In the K-meson system, this analysis is applied to the calculation of the weak decay amplitudes, weak mixing and CP violation. 10 refs., 5 figs., 2 tabs
On n-weak amenability of Rees semigroup algebras
Indian Academy of Sciences (India)
semigroups. In this work, we shall consider this class of Banach algebras. We examine the n-weak amenability of some semigroup algebras, and give an easier example of a Banach algebra which is n-weakly amenable if n is odd. Let L1(G) be the group algebra of a locally compact group G (§3.3 of [3]). Then Johnson.
The Maslov index in weak symplectic functional analysis
DEFF Research Database (Denmark)
Booss-Bavnbek, Bernhelm; Zhu, Chaofeng
We recall the Chernoff-Marsden definition of weak symplectic structure and give a rigorous treatment of the functional analysis and geometry of weak symplectic Banach spaces. We define the Maslov index of a continuous path of Fredholm pairs of Lagrangian subspaces in continuously varying Banach...
Introduction to unification of electromagnetic and weak interactions
International Nuclear Information System (INIS)
Martin, F.
After reviewing the present status of weak interaction phenomenology we discuss the basic principles of gauge theories. Then we show how Higgs mechanism can give massive quanta of interaction. The so-called 'Weinberg-Salam' model, which unifies electromagnetic and weak interactions, is described. We conclude with a few words on unification with strong interactions and gravity [fr
High-redshift SDSS Quasars with Weak Emission Lines
DEFF Research Database (Denmark)
Diamond-Stanic, Aleksandar M.; Fan, Xiaohui; Brandt, W. N.
We identify a sample of 74 high-redshift quasars (z > 3) with weak emission lines from the Fifth Data Release of the Sloan Digital Sky Survey and present infrared, optical, and radio observations of a subsample of four objects at z > 4. These weak emission-line quasars (WLQs) constitute a promine...
Measures of weak noncompactness, nonlinear Leray-Schauder ...
African Journals Online (AJOL)
In this paper, we establish some new nonlinear Leray-Schauder alternatives for the sum and the product of weakly sequentially continuous operators in Banach algebras satisfying certain sequential condition (P). The main condition in our results is formulated in terms of axiomatic measures of weak noncompactness.
Equilibration and hydrodynamics at strong and weak coupling
Schee, Wilke van der
We give an updated overview of both weak and strong coupling methods to describe the approach to a plasma described by viscous hydrodynamics, a process now called hydrodynamisation. At weak coupling the very first moments after a heavy ion collision is described by the colour-glass condensate
A young woman with weakness of the legs
African Journals Online (AJOL)
A previously well 22-year-old woman presented with progressive weakness of her legs and urinary incontinence over 7 days. Clinically she was healthy, with no skin rashes. On neurological examination she had profound bilateral weakness of the lower limbs, hypertonia, hyperreflexia, a positive Babinski sign and a T6 ...
Microwave-assisted Weak Acid Hydrolysis of Proteins
Directory of Open Access Journals (Sweden)
Miyeong Seo
Full Text Available Myoglobin was hydrolyzed by microwave-assisted weak acid hydrolysis with 2% formic acid at 37 oC, 50 oC, and100 oC for 1 h. The most effective hydrolysis was observed at 100 oC. Hydrolysis products were investigated using matrixassistedlaser desorption/ionization time-of-flight mass spectrometry. Most cleavages predominantly occurred at the C-termini ofaspartyl residues. For comparison, weak acid hydrolysis was also performed in boiling water for 20, 40, 60, and 120 min. A 60-min weak acid hydrolysis in boiling water yielded similar results as a 60-min microwave-assisted weak acid hydrolysis at100 oC. These results strongly suggest that microwave irradiation has no notable enhancement effect on acid hydrolysis of proteinsand that temperature is the major factor that determines the effectiveness of weak acid hydrolysis.
A survey of matrix theory and matrix inequalities
Marcus, Marvin
Written for advanced undergraduate students, this highly regarded book presents an enormous amount of information in a concise and accessible format. Beginning with the assumption that the reader has never seen a matrix before, the authors go on to provide a survey of a substantial part of the field, including many areas of modern research interest.Part One of the book covers not only the standard ideas of matrix theory, but ones, as the authors state, ""that reflect our own prejudices,"" among them Kronecker products, compound and induced matrices, quadratic relations, permanents, incidence
Octonionic matrix representation and electromagnetism
Energy Technology Data Exchange (ETDEWEB)
Chanyal, B. C. [Kumaun University, S. S. J. Campus, Almora (India)
Keeping in mind the important role of octonion algebra, we have obtained the electromagnetic field equations of dyons with an octonionic 8 x 8 matrix representation. In this paper, we consider the eight - dimensional octonionic space as a combination of two (external and internal) four-dimensional spaces for the existence of magnetic monopoles (dyons) in a higher-dimensional formalism. As such, we describe the octonion wave equations in terms of eight components from the 8 x 8 matrix representation. The octonion forms of the generalized potential, fields and current source of dyons in terms of 8 x 8 matrix are discussed in a consistent manner. Thus, we have obtained the generalized Dirac-Maxwell equations of dyons from an 8x8 matrix representation of the octonion wave equations in a compact and consistent manner. The generalized Dirac-Maxwell equations are fully symmetric Maxwell equations and allow for the possibility of magnetic charges and currents, analogous to electric charges and currents. Accordingly, we have obtained the octonionic Dirac wave equations in an external field from the matrix representation of the octonion-valued potentials of dyons.
International Nuclear Information System (INIS)
Heggarty, J.W.
For almost thirty years, sequential R-matrix computation has been used by atomic physics research groups, from around the world, to model collision phenomena involving the scattering of electrons or positrons with atomic or molecular targets. As considerable progress has been made in the understanding of fundamental scattering processes, new data, obtained from more complex calculations, is of current interest to experimentalists. Performing such calculations, however, places considerable demands on the computational resources to be provided by the target machine, in terms of both processor speed and memory requirement. Indeed, in some instances the computational requirements are so great that the proposed R-matrix calculations are intractable, even when utilising contemporary classic supercomputers. Historically, increases in the computational requirements of R-matrix computation were accommodated by porting the problem codes to a more powerful classic supercomputer. Although this approach has been successful in the past, it is no longer considered to be a satisfactory solution due to the limitations of current (and future) Von Neumann machines. As a consequence, there has been considerable interest in the high performance multicomputers, that have emerged over the last decade which appear to offer the computational resources required by contemporary R-matrix research. Unfortunately, developing codes for these machines is not as simple a task as it was to develop codes for successive classic supercomputers. The difficulty arises from the considerable differences in the computing models that exist between the two types of machine and results in the programming of multicomputers to be widely acknowledged as a difficult, time consuming and error-prone task. Nevertheless, unless parallel R-matrix computation is realised, important theoretical and experimental atomic physics research will continue to be hindered. This thesis describes work that was undertaken in
Numerical methods in matrix computations
Björck, Åke
Matrix algorithms are at the core of scientific computing and are indispensable tools in most applications in engineering. This book offers a comprehensive and up-to-date treatment of modern methods in matrix computation. It uses a unified approach to direct and iterative methods for linear systems, least squares and eigenvalue problems. A thorough analysis of the stability, accuracy, and complexity of the treated methods is given. Numerical Methods in Matrix Computations is suitable for use in courses on scientific computing and applied technical areas at advanced undergraduate and graduate level. A large bibliography is provided, which includes both historical and review papers as well as recent research papers. This makes the book useful also as a reference and guide to further study and research work. Åke Björck is a professor emeritus at the Department of Mathematics, Linköping University. He is a Fellow of the Society of Industrial and Applied Mathematics.
Lectures on matrix field theory
Ydri, Badis
These lecture notes provide a systematic introduction to matrix models of quantum field theories with non-commutative and fuzzy geometries. The book initially focuses on the matrix formulation of non-commutative and fuzzy spaces, followed by a description of the non-perturbative treatment of the corresponding field theories. As an example, the phase structure of non-commutative phi-four theory is treated in great detail, with a separate chapter on the multitrace approach. The last chapter offers a general introduction to non-commutative gauge theories, while two appendices round out the text. Primarily written as a self-study guide for postgraduate students – with the aim of pedagogically introducing them to key analytical and numerical tools, as well as useful physical models in applications – these lecture notes will also benefit experienced researchers by providing a reference guide to the fundamentals of non-commutative field theory with an emphasis on matrix models and fuzzy geometries.
Supersymmetry in random matrix theory
International Nuclear Information System (INIS)
Kieburg, Mario
I study the applications of supersymmetry in random matrix theory. I generalize the supersymmetry method and develop three new approaches to calculate eigenvalue correlation functions. These correlation functions are averages over ratios of characteristic polynomials. In the first part of this thesis, I derive a relation between integrals over anti-commuting variables (Grassmann variables) and differential operators with respect to commuting variables. With this relation I rederive Cauchy- like integral theorems. As a new application I trace the supermatrix Bessel function back to a product of two ordinary matrix Bessel functions. In the second part, I apply the generalized Hubbard-Stratonovich transformation to arbitrary rotation invariant ensembles of real symmetric and Hermitian self-dual matrices. This extends the approach for unitarily rotation invariant matrix ensembles. For the k-point correlation functions I derive supersymmetric integral expressions in a unifying way. I prove the equivalence between the generalized Hubbard-Stratonovich transformation and the superbosonization formula. Moreover, I develop an alternative mapping from ordinary space to superspace. After comparing the results of this approach with the other two supersymmetry methods, I obtain explicit functional expressions for the probability densities in superspace. If the probability density of the matrix ensemble factorizes, then the generating functions exhibit determinantal and Pfaffian structures. For some matrix ensembles this was already shown with help of other approaches. I show that these structures appear by a purely algebraic manipulation. In this new approach I use structures naturally appearing in superspace. I derive determinantal and Pfaffian structures for three types of integrals without actually mapping onto superspace. These three types of integrals are quite general and, thus, they are applicable to a broad class of matrix ensembles. (orig.)
Supersymmetry in random matrix theory
Energy Technology Data Exchange (ETDEWEB)
Kieburg, Mario
I study the applications of supersymmetry in random matrix theory. I generalize the supersymmetry method and develop three new approaches to calculate eigenvalue correlation functions. These correlation functions are averages over ratios of characteristic polynomials. In the first part of this thesis, I derive a relation between integrals over anti-commuting variables (Grassmann variables) and differential operators with respect to commuting variables. With this relation I rederive Cauchy- like integral theorems. As a new application I trace the supermatrix Bessel function back to a product of two ordinary matrix Bessel functions. In the second part, I apply the generalized Hubbard-Stratonovich transformation to arbitrary rotation invariant ensembles of real symmetric and Hermitian self-dual matrices. This extends the approach for unitarily rotation invariant matrix ensembles. For the k-point correlation functions I derive supersymmetric integral expressions in a unifying way. I prove the equivalence between the generalized Hubbard-Stratonovich transformation and the superbosonization formula. Moreover, I develop an alternative mapping from ordinary space to superspace. After comparing the results of this approach with the other two supersymmetry methods, I obtain explicit functional expressions for the probability densities in superspace. If the probability density of the matrix ensemble factorizes, then the generating functions exhibit determinantal and Pfaffian structures. For some matrix ensembles this was already shown with help of other approaches. I show that these structures appear by a purely algebraic manipulation. In this new approach I use structures naturally appearing in superspace. I derive determinantal and Pfaffian structures for three types of integrals without actually mapping onto superspace. These three types of integrals are quite general and, thus, they are applicable to a broad class of matrix ensembles. (orig.)
Polychoric/Tetrachoric Matrix or Pearson Matrix? A methodological study
Directory of Open Access Journals (Sweden)
Dominguez Lara, Sergio Alexis
Full Text Available The use of product-moment correlation of Pearson is common in most studies in factor analysis in psychology, but it is known that this statistic is only applicable when the variables related are in interval scale and normally distributed, and when are used in ordinal data may to produce a distorted correlation matrix . Thus is a suitable option using polychoric/tetrachoric matrices in item-level factor analysis when the items are in level measurement nominal or ordinal. The aim of this study was to show the differences in the KMO, Bartlett`s Test and Determinant of the Matrix, percentage of variance explained and factor loadings in depression trait scale of Depression Inventory Trait - State and the Neuroticism dimension of the short form of the Eysenck Personality Questionnaire -Revised, regarding the use of matrices polychoric/tetrachoric matrices and Pearson. These instruments was analyzed with different extraction methods (Maximum Likelihood, Minimum Rank Factor Analysis, Unweighted Least Squares and Principal Components, keeping constant the rotation method Promin were analyzed. Were observed differences regarding sample adequacy measures, as well as with respect to the explained variance and the factor loadings, for solutions having as polychoric/tetrachoric matrix. So it can be concluded that the polychoric / tetrachoric matrix give better results than Pearson matrices when it comes to item-level factor analysis using different methods.
Towards Google matrix of brain
Energy Technology Data Exchange (ETDEWEB)
Shepelyansky, D.L., E-mail: email@example.com [Laboratoire de Physique Theorique (IRSAMC), Universite de Toulouse, UPS, F-31062 Toulouse (France); LPT - IRSAMC, CNRS, F-31062 Toulouse (France); Zhirov, O.V. [Budker Institute of Nuclear Physics, 630090 Novosibirsk (Russian Federation)
We apply the approach of the Google matrix, used in computer science and World Wide Web, to description of properties of neuronal networks. The Google matrix G is constructed on the basis of neuronal network of a brain model discussed in PNAS 105 (2008) 3593. We show that the spectrum of eigenvalues of G has a gapless structure with long living relaxation modes. The PageRank of the network becomes delocalized for certain values of the Google damping factor {alpha}. The properties of other eigenstates are also analyzed. We discuss further parallels and similarities between the World Wide Web and neuronal networks.
Towards Google matrix of brain
International Nuclear Information System (INIS)
Shepelyansky, D.L.; Zhirov, O.V.
We apply the approach of the Google matrix, used in computer science and World Wide Web, to description of properties of neuronal networks. The Google matrix G is constructed on the basis of neuronal network of a brain model discussed in PNAS 105 (2008) 3593. We show that the spectrum of eigenvalues of G has a gapless structure with long living relaxation modes. The PageRank of the network becomes delocalized for certain values of the Google damping factor α. The properties of other eigenstates are also analyzed. We discuss further parallels and similarities between the World Wide Web and neuronal networks.
Inverse Interval Matrix: A Survey
Czech Academy of Sciences Publication Activity Database
Rohn, Jiří; Farhadsefat, R.
Roč. 22, - (2011), s. 704-719 E-ISSN 1081-3810 R&D Projects: GA ČR GA201/09/1957; GA ČR GC201/08/J020 Institutional research plan: CEZ:AV0Z10300504 Keywords : interval matrix * inverse interval matrix * NP-hardness * enclosure * unit midpoint * inverse sign stability * nonnegative invertibility * absolute value equation * algorithm Subject RIV: BA - General Mathematics Impact factor: 0.808, year: 2010 http://www.math.technion.ac.il/iic/ ela / ela -articles/articles/vol22_pp704-719.pdf
Symmetries and Interactions in Matrix String Theory
Hacquebord, F.H.
This PhD-thesis reviews matrix string theory and recent developments therein. The emphasis is put on symmetries, interactions and scattering processes in the matrix model. We start with an introduction to matrix string theory and a review of the orbifold model that flows out of matrix string theory
Chiral perturbation theory approach to hadronic weak amplitudes
International Nuclear Information System (INIS)
Rafael, E. de
We are concerned with applications to the non-leptonic weak interactions in the sector of light quark flavors: u, d and s. Both strangeness changing ΔS=1 and ΔS=2 non-leptonic transitions can be described as weak perturbations to the strong effective chiral Lagrangian; the chiral structure of the weak effective Lagrangian being dictated by the transformation properties of the weak non-leptonic Hamiltonian of the Standard Model under global SU(3) Left xSU(3) Right rotations of the quark-fields. These lectures are organized as follows. Section 2 gives a review of the basic properties of chiral symmetry. Section 3 explains the effective chiral realization of the non-leptonic weak Hamiltonian of the Standard Model to lowest order in derivatives and masses. Section 4 deals with non-leptonic weak transitions in the presence of electromagnetism. Some recent applications to radiative kaon decays are reviewed and the effect of the so called electromagnetic penguin like diagrams is also discussed. Section 5 explains the basic ideas of the QCD-hadronic duality approach to the evaluation of coupling constants of the non-leptonic chiral weak Lagrangian. (orig./HSI)
Density matrix embedding in an antisymmetrized geminal power bath
International Nuclear Information System (INIS)
Tsuchimochi, Takashi; Welborn, Matthew; Van Voorhis, Troy
Density matrix embedding theory (DMET) has emerged as a powerful tool for performing wave function-in-wave function embedding for strongly correlated systems. In traditional DMET, an accurate calculation is performed on a small impurity embedded in a mean field bath. Here, we extend the original DMET equations to account for correlation in the bath via an antisymmetrized geminal power (AGP) wave function. The resulting formalism has a number of advantages. First, it allows one to properly treat the weak correlation limit of independent pairs, which DMET is unable to do with a mean-field bath. Second, it associates a size extensive correlation energy with a given density matrix (for the models tested), which AGP by itself is incapable of providing. Third, it provides a reasonable description of charge redistribution in strongly correlated but non-periodic systems. Thus, AGP-DMET appears to be a good starting point for describing electron correlation in molecules, which are aperiodic and possess both strong and weak electron correlation
Prevalence of Weak D Antigen In Western Indian Population
Directory of Open Access Journals (Sweden)
Tanvi Sadaria
Full Text Available Introduction: Discovery of Rh antigens in 1939 by Landsteiner and Weiner was the revolutionary stage in blood banking. Of these antigens, D, which decides Rh positivity or negativity, is the most antigenic. A problem is encountered when an individual has a weakened expression of D (Du, i.e., fewer numbers of D antigens on red cell membrane. Aims and Objectives: To know the prevalence of weak D in Indian population because incidence varies in different population. To determine the risk of alloimmunization among Rh D negative patients who receives the blood of weak D positive donors. Material and Methods: Rh grouping of 38,962 donors who came to The Department of Immunohematology and Blood Transfusion of Civil Hospital, Ahmedabad from 1st January 2013 to 30th September 2014 was done using the DIAGAST (Automated Grouping. The samples that tested negative for D antigen were further analysed for weak D (Du by indirect antiglobulin test using blend of Ig G and Ig M Anti D. This was done using Column agglutination method in ID card (gel card. Results: The total number of donors studied was 38,962. Out of these 3360(8.6% were tested Rh D negative. All Rh D negative donors were tested for weak D (Du. 22 (0.056% of total donors and 0.65% of Rh negative donors turned out to be weak D (Du positive. Conclusion: The prevalence of weak D (Du in Western Indian population is 0.056 %, So the risk of alloimmunization in our setting due to weak D (Du antigen is marginal. But, testing of weak D antigen is necessary in blood bank because weak D antigen is immunogenic and can produce alloimmunization if transfused to Rh D negative subjects.
Precision phase estimation based on weak-value amplification
Qiu, Xiaodong; Xie, Linguo; Liu, Xiong; Luo, Lan; Li, Zhaoxue; Zhang, Zhiyou; Du, Jinglei
In this letter, we propose a precision method for phase estimation based on the weak-value amplification (WVA) technique using a monochromatic light source. The anomalous WVA significantly suppresses the technical noise with respect to the intensity difference signal induced by the phase delay when the post-selection procedure comes into play. The phase measured precision of this method is proportional to the weak-value of a polarization operator in the experimental range. Our results compete well with the wide spectrum light phase weak measurements and outperform the standard homodyne phase detection technique.
Detection of weak optical signals with a laser amplifier
International Nuclear Information System (INIS)
Kozlovskii, A. V.
Detection of weak and extremely weak light signals amplified by linear and four-wave mixing laser amplifiers is analyzed. Photoelectron distributions are found for different input photon statistics over a wide range of gain. Signal-to-noise ratios are calculated and analyzed for preamplification schemes using linear and four-wave mixing amplifiers. Calculations show that the high signal-to-noise ratio (much higher than unity), ensuring reliable detection of weak input signals, can be attained only with a four-wave mixing preamplification scheme. Qualitative dependence of the signal-to-noise ratio on the quantum statistical properties of both signal and idler waves is demonstrated
The definite article in Romance expletives and long weak definites
Directory of Open Access Journals (Sweden)
M.Teresa Espinal
Full Text Available This paper focuses on some issues involving expletive articles and long weak definites in Romance (mainly Spanish, Brazilian Portuguese and Catalan, in comparison to DPs that elicit a strong reading. We show the similarities between expletive definites and long weak definites, and we argue for an analysis in common to other polarity items in terms of polarity sensitivity. We reach the conclusion that the definite article in Romance comes in two variants: the referentially unique variant (to be translated as the semantic 'iota 'operator and the polar variant, formally characterized with an abstract [+σ] feature, that encodes a weak bound reading (to be semantically translated by an existential operator.
Linear optics implementation of weak values in Hardy's paradox
International Nuclear Information System (INIS)
Ahnert, S.E.; Payne, M.C.
We propose an experimental setup for the implementation of weak measurements in the context of the gedanken experiment known as Hardy's paradox. As Aharonov et al. [Y. Aharonov, A. Botero, S. Popescu, B. Reznik, and J. Tollaksen, Phys. Lett. A301, 130 (2002)] showed, these weak values form a language with which the paradox can be resolved. Our analysis shows that this language is indeed consistent and experimentally testable. It also reveals exactly how a combination of weak values can give rise to an apparently paradoxical result
The quantum to classical crossover for a weak link capacitor
International Nuclear Information System (INIS)
Spiller, T.P.; Clark, T.D.; Prance, H.; Prance, R.J.
We consider a model weak link, an ultra-small capacitor subject to tunnelling, to ohmic dissipation and fed with an external displacement current. The framework we employ is the new approach of quantum state diffusion, which treats individual open quantum systems as well as being able to generate the conventional ensemble averages. We show how evidence, for archetypal quantum behaviour (coherent oscillations) and archetypal classical behaviour (chaos) arises, for weak links whose parameters are related by a rather modest scaling. Interestingly, the quantum behaviour can arise for a weak link with intrinsic parameter values such that it could exhibit chaos, if it were a purely classical device
Nonperturbative theory of weak pre- and post-selected measurements
Energy Technology Data Exchange (ETDEWEB)
Kofman, Abraham G., E-mail: email@example.com; Ashhab, Sahel; Nori, Franco
This paper starts with a brief review of the topic of strong and weak pre- and post-selected (PPS) quantum measurements, as well as weak values, and afterwards presents original work. In particular, we develop a nonperturbative theory of weak PPS measurements of an arbitrary system with an arbitrary meter, for arbitrary initial states of the system and the meter. New and simple analytical formulas are obtained for the average and the distribution of the meter pointer variable. These formulas hold to all orders in the weak value. In the case of a mixed preselected state, in addition to the standard weak value, an associated weak value is required to describe weak PPS measurements. In the linear regime, the theory provides the generalized Aharonov–Albert–Vaidman formula. Moreover, we reveal two new regimes of weak PPS measurements: the strongly-nonlinear regime and the inverted region (the regime with a very large weak value), where the system-dependent contribution to the pointer deflection decreases with increasing the measurement strength. The optimal conditions for weak PPS measurements are obtained in the strongly-nonlinear regime, where the magnitude of the average pointer deflection is equal or close to the maximum. This maximum is independent of the measurement strength, being typically of the order of the pointer uncertainty. In the optimal regime, the small parameter of the theory is comparable to the overlap of the pre- and post-selected states. We show that the amplification coefficient in the weak PPS measurements is generally a product of two qualitatively different factors. The effects of the free system and meter Hamiltonians are discussed. We also estimate the size of the ensemble required for a measurement and identify optimal and efficient meters for weak measurements. Exact solutions are obtained for a certain class of the measured observables. These solutions are used for numerical calculations, the results of which agree with the theory
Nonperturbative theory of weak pre- and post-selected measurements
International Nuclear Information System (INIS)
Kofman, Abraham G.; Ashhab, Sahel; Nori, Franco
This paper starts with a brief review of the topic of strong and weak pre- and post-selected (PPS) quantum measurements, as well as weak values, and afterwards presents original work. In particular, we develop a nonperturbative theory of weak PPS measurements of an arbitrary system with an arbitrary meter, for arbitrary initial states of the system and the meter. New and simple analytical formulas are obtained for the average and the distribution of the meter pointer variable. These formulas hold to all orders in the weak value. In the case of a mixed preselected state, in addition to the standard weak value, an associated weak value is required to describe weak PPS measurements. In the linear regime, the theory provides the generalized Aharonov–Albert–Vaidman formula. Moreover, we reveal two new regimes of weak PPS measurements: the strongly-nonlinear regime and the inverted region (the regime with a very large weak value), where the system-dependent contribution to the pointer deflection decreases with increasing the measurement strength. The optimal conditions for weak PPS measurements are obtained in the strongly-nonlinear regime, where the magnitude of the average pointer deflection is equal or close to the maximum. This maximum is independent of the measurement strength, being typically of the order of the pointer uncertainty. In the optimal regime, the small parameter of the theory is comparable to the overlap of the pre- and post-selected states. We show that the amplification coefficient in the weak PPS measurements is generally a product of two qualitatively different factors. The effects of the free system and meter Hamiltonians are discussed. We also estimate the size of the ensemble required for a measurement and identify optimal and efficient meters for weak measurements. Exact solutions are obtained for a certain class of the measured observables. These solutions are used for numerical calculations, the results of which agree with the theory