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9,000 | Suppose that you have an abstract for a scientific paper: due to decoherence , realistic quantum systems inevitably interact with the environment when quantum information is processed , which causes the loss of quantum properties . as a fundamental issue of quantum properties ,
quantum correlations have attracted a lot of interests in recent years .
because of the importance of high dimensional systems in quantum information , in this work , we study the quantum correlations affected by the markovian environment by considering the quantum correlations of qutrit - qutrit quantum systems measured by the negativity and the geometric discord .
the local noise channels covered in this work includes dephasing , trit - flip , trit - phase - flip , and depolarising channels .
we have also investigated the cases where the local decoherence channels of two sides are identical and non - identical . .
And you have already written the first three sentences of the full article: quantum correlations , which lie in the foundations of quantum theory , have been of renewed interest during the last two decades as the field of quantum information science emerged and matured . quantum entanglement , as a kind of quantum correlations , has been playing central roles in quantum information and computation @xcite .
the negativity is one of the best known and most popular tools of quantifying bipartite quantum entanglement .
it can be computed easily for arbitrary states of a composite system ..
Please generate the next two sentences of the article | therefore , it has received various studies @xcite . however , quantum entanglement does not account for all of the non - classical properties of quantum phenomenons .
therefore , numerous quantifiers of quantum correlations have been further proposed to reveal the non - classical correlations that can not be fully captured by quantum entanglement @xcite . among the various measures |
9,001 | Suppose that you have an abstract for a scientific paper: within the framework of quark mass matrices with a democratic texture , the unitary rotation matrices that diagonalize the quark matrices are obtained by a specific parametrization of the cabibbo - kobayashi - maskawa mixing matrix .
different forms of democratic quark mass matrices are derived from slightly different parametrizations . .
And you have already written the first three sentences of the full article: the standard model is flawed by the large number of free parameters , for which there is at present no explanation .
there is no prediction of the family replication pattern , nor of the number of families .
all the families are really treated on the same footing . most of the standard model free parameters reside in `` flavour space '' - with six quark masses , six lepton masses , four quark mixing angles and ditto for the leptonic sector , as well as the strong cp - violating parameter @xmath0 ..
Please generate the next two sentences of the article | the structure of flavour space is determined by the fermion mass matrices , i.e. by the form that the mass matrices take in the `` weak interaction basis '' where mixed fermion states interact weakly , in contrast to the `` mass bases '' , where the mass matrices are diagonal .
one may wonder how one may ascribe such importance to the different bases in flavour space , considering that the information content of a matrix is contained in its matrix invariants , which in the case of a @xmath1 matrix @xmath2 are the @xmath3 sums and products of the eigenvalues @xmath4 , such as @xmath5 , @xmath6 , @xmath7 these expressions are invariant under permutations of the eigenvalues , which in the context of mass matrices means that they are flavour symmetric , and obviously independent of any choice of flavour space basis . |
9,002 | Suppose that you have an abstract for a scientific paper: we present simple models of particulate materials whose mechanical integrity arises from a jamming process .
we argue that such media are generically fragile " , that is , they are unable to support certain types of incremental loading without plastic rearrangement . in such models ,
fragility is naturally linked to the marginal stability of force chain networks ( granular skeletons ) within the material .
fragile matter exhibits novel mechanical responses that may be relevant to both jammed colloids and cohesionless assemblies of poured , rigid grains .
[ multiblock footnote omitted ] .
And you have already written the first three sentences of the full article: in this paper , we consider the relation between jamming ( a kinetic process ) and the laws of static mechanical equilibrium of particulate media .
we describe first a simple model of jamming in a colloid , sheared between parallel plates .
we assume that force chains ( linear arrays of rigid particles in contact ) develop along the major stress compression axis and span the sample ..
Please generate the next two sentences of the article | the resulting jammed state can support a shear stress indefinitely , but does this by virtue of a self - organized internal structure ( the force chain array ) which has developed in direct response to the applied load itself . if a different load is now applied ( e.g. if the material is sheared in some different direction ) , the force chains can not sustain the load but must flow and rejam in a different configuration .
the model thus provides a simple example of a fragile " material one which can not support certain types of infinitesimal stress increment without plastic reorganisation . |
9,003 | Suppose that you have an abstract for a scientific paper: given a hyperelliptic klein surface , we construct companion klein bottles , extending our technique of companion tori already exploited by the authors in the genus @xmath0 case .
bavard s short loops on such companion surfaces are studied in relation to the original surface so to improve a systolic inequality of gromov s .
a basic idea is to use length bounds for loops on a companion klein bottle , and then analyze how curves transplant to the original non - orientable surface .
we exploit the real structure on the orientable double cover by applying the coarea inequality to the distance function from the real locus .
of particular interest is the case of dyck s surface .
we also exploit an optimal systolic bound for the mbius band , due to blatter . supported by the israel science foundation grant 1294/06 ] primary 53c23 ; secondary 30f10 , 58j60 .
And you have already written the first three sentences of the full article: systolic inequalities for surfaces compare length and area , and can therefore be thought of as `` opposite '' isoperimetric inequalities .
the study of such inequalities was initiated by c. loewner in 1949 when he proved his torus inequality for @xmath1 ( see pu @xcite and horowitz _ et al . _
the systole , denoted `` sys '' , of a space is the least length of a loop which can not be contracted to a point in the space , and is therefore a natural generalisation of the _ girth _ invariant of graphs ..
Please generate the next two sentences of the article | every metric on the @xmath0-dimensional torus @xmath2 satisfies the bound @xmath3 in higher dimensions , m. gromov s deep result @xcite , relying on filling invariants , exhibits a universal upper bound for the systole in terms of the total volume of an essential manifold .
l. guth @xcite recently found an alternative proof not relying on filling invariants , and giving a generalisation of gromov s inequality , see also ambrosio and katz @xcite . in dimension @xmath0 , |
9,004 | Suppose that you have an abstract for a scientific paper: we introduce the notion of gepner type bridgeland stability conditions on triangulated categories , which depends on a choice of an autoequivalence and a complex number .
we conjecture the existence of gepner type stability conditions on the triangulated categories of graded matrix factorizations of weighted homogeneous polynomials . such a stability condition may give a natural stability condition for landau - ginzburg b - branes , and correspond to the gepner point of the stringy k@xmath0hler moduli space of a quintic 3-fold .
the main result is to show our conjecture when the variety defined by the weighted homogeneous polynomial is a complete intersection of hyperplanes in a calabi - yau manifold with dimension less than or equal to two . .
And you have already written the first three sentences of the full article: the donaldson - thomas ( dt ) invariants enumerate semistable coherent sheaves on calabi - yau 3-folds , which have drawn much attention recently @xcite .
we are in interested in the following two problems in dt theory : * find constraints among dt invariants induced by autoequivalences of the derived category of coherent sheaves , e.g. seidel - thomas twists @xcite . *
construct dt type invariants counting b - branes on landau - ginzburg ( lg ) models associated to a superpotential ..
Please generate the next two sentences of the article | as for the former problem , there are several predictions in string theory on generating series of dt invariants , e.g. @xmath1-duality conjecture , ooguri - strominger - vafa conjecture @xcite , @xcite .
there seem to be mysterious constraints among dt invariants behind such predictions , and we hope to reveal their origins via symmetries in the derived category . we believe that a key step toward this problem is to construct a bridgeland stability condition on the derived category @xcite satisfying a certain symmetric property with respect to the given autoequivalence . indeed a construction of a ( weak ) stability condition which is preserved under the derived dual , together with wall - crossing arguments @xcite , @xcite , play crucial roles in the proof of the rationality of the generating series of rank one dt type invariants counting curves @xcite , @xcite , @xcite . as for the latter problem , in order to define the dt type invariants , we need to fix a stability condition for b - branes on lg models |
9,005 | Suppose that you have an abstract for a scientific paper: a quantum two level system coupled to a harmonic oscillator represents a ubiquitous physical system .
new experiments in circuit qed and nano - electromechanical systems ( nems ) achieve unprecedented coupling strength at large detuning between qubit and oscillator , thus requiring a theoretical treatment beyond the jaynes cummings model . here
we present a new method for describing the qubit dynamics in this regime , based on an oscillator correlation function expansion of a non - markovian master equation in the polaron frame .
our technique yields a new numerical method as well as a succinct approximate expression for the qubit dynamics .
we obtain a new expression for the ac stark shift and show that this enables practical and precise qubit thermometry of an oscillator .
the qubit - oscillator model has gone by many names in many fields , owing its tenacity to the breadth of its applicability : it is the simplest non - trivial model of the interaction between light and matter . at its inception
it was used to describe the interaction of an atom with a magnetic field @xcite , and referred to thereafter as the rabi model . in the subsequent decades
it has been extensively studied in quantum optics @xcite and cavity qed @xcite .
physical chemists have used a ` vibration - dimer ' model to study the spectra of molecules @xcite . applying the rotating wave approximation ( rwa ) to the rabi model
yields the jaynes cummings model ( jcm ) @xcite , which is valid when the detuning between the qubit transition frequency @xmath0 and the resonator frequency @xmath1 is negligible @xmath2 and the coupling between the qubit and oscillator is weak @xmath3 @xcite .
this is an excellent approximation in the case of cavity qed where typical coupling strengths are of order @xmath4 .
the jcm can be extended to incorporate tunnelling , and has provided an adequate description of experiments for decades , but a new era of experiments are pushing beyond its boundaries in terms of both coupling and....
And you have already written the first three sentences of the full article: in this appendix we give the explicit derivation of the equations of motion ( [ eqn : psol1]-[eqn : psol4 ] ) , the laplace transformed equations of motion ( [ eqn : rsol1],[eqn : rsol2 ] ) , and the bosonic correlation function ( [ eqn : bosoncf ] ) . we note that parts of these derivations can be found in similar form in the literature ( cf .
@xcite ) , but we here give an alternate and full account in consistent notation for the benefit of the reader . at this point
we make the born approximation ( assuming the density matrix of system and bath are factorable ) @xmath98 the bosonic correlation function is defined as @xmath99 : @xmath100.\ ] ] where the subscript @xmath101 represents the bosonic degrees of freedom ..
Please generate the next two sentences of the article | we substitute this into ( [ eqn : efmo ] ) and by assuming there is no initial coherence in the system we obtain ( [ eqn : psol1 ] - [ eqn : psol4 ] ) .
the bosonic correlation function ( [ eqn : bosoncf ] ) for an oscillator with a single mode in a thermal state is defined as : @xmath102 , \qquad \rho_b = \frac{\exp(- \beta \omega { \ensuremath{{\ensuremath{a^\dagger}}{\ensuremath{a}}}})}{\text{tr}_b [ \exp(- \beta \omega { \ensuremath{{\ensuremath{a^\dagger}}{\ensuremath{a } } } } ) } = \frac{1}{z } \exp(- \beta \omega { \ensuremath{{\ensuremath{a^\dagger}}{\ensuremath{a } } } } ) . |
9,006 | Suppose that you have an abstract for a scientific paper: the rare decay @xmath0 was studied with the e391a detector at the kek 12-gev proton synchrotron . based on
@xmath1 @xmath2 decays , an upper limit of @xmath3 was obtained for the branching fraction at 90@xmath4 confidence level .
we also set a limit on the @xmath5 invisible particles ) process ; the limit on the branching fraction varied from 7.0@xmath6 to 4.0@xmath7 for the mass of @xmath8 ranging from 50 mev/@xmath9 to 200 mev/@xmath9 . .
And you have already written the first three sentences of the full article: in the standard electroweak theory , flavor - changing neutral current ( fcnc ) processes are strongly suppressed and can only occur via higher - order effects .
hence , these processes will be sensitive to unknown particles or interactions that contribute in higher - order loop diagrams .
such processes are ideal places to look for signals of new physics beyond the standard model ( sm ) . in the sm ,.
Please generate the next two sentences of the article | the fcnc @xmath0 decay is predominantly a cp conserving process .
its branching fraction is sensitive to the real part of the @xmath10 transition amplitude , while the related decays @xmath11 and @xmath12 sense the imaginary part and absolute value , respectively . like these decays , |
9,007 | Suppose that you have an abstract for a scientific paper: we provide the power spectrum of small scalar perturbations propagating in an inflationary scenario within loop quantum cosmology .
we consider the hybrid quantization approach applied to a friedmann robertson walker spacetime with flat spatial sections coupled to a massive scalar field .
we study the quantum dynamics of scalar perturbations on an effective background within this hybrid approach .
we consider in our study adiabatic states of different orders . for them , we find that the hybrid quantization is in good agreement with the predictions of the dressed metric approach .
we also propose an initial vacuum state for the perturbations , and compute the primordial and the anisotropy power spectrum in order to qualitatively compare with the current observations of planck mission .
we find that our vacuum state is in good agreement with them , showing a suppression of the power spectrum for large scale anisotropies .
we compare with other choices already studied in the literature . .
And you have already written the first three sentences of the full article: the paradigm of inflation provides nowadays a simple and accurate description of many of the aspects of the universe we observe .
it is able to naturally explain several questions like the particle horizon or the flatness problems of early cosmology , among others @xcite .
remarkably , this paradigm also explains the origin of the large scale structure ..
Please generate the next two sentences of the article | it requires , however , the quantum principles for this mechanism to work @xcite .
then , it is one of the most favorable situations where quantum gravity phenomena can potentially be detected . |
9,008 | Suppose that you have an abstract for a scientific paper: we use a hadron resonance gas model to calculate the quark - antiquark condensates for light ( up and down ) and strange quark flavors at finite temperatures and chemical potentials . at zero chemical potentials
, we find that at the temperature where the light quark - antiquark condensates entirely vanish the strange quark - antiquark condensate still keeps a relatively large fraction of its value in the vacuum .
this is in agreement with results obtained in lattice simulations and in chiral perturbation theory at finite temperature and zero chemical potentials .
furthermore , we find that this effect slowly disappears at larger baryon chemical potential
. these results might have significant consequences for our understanding of qcd at finite temperatures and chemical potentials . concretely ,
our results imply that there might be a domain of temperatures where chiral symmetry is restored for light quarks , but still broken for strange quark that persists at small chemical potentials .
this might have practical consequences for heavy ion collision experiments . .
And you have already written the first three sentences of the full article: there are many important physical systems where the strong interaction at nonzero temperature and density plays a crucial role : e.g. , neutron stars , heavy - ion collision experiments , and the early universe . to understand these systems , we need to better grasp the phase diagram of qcd at nonzero temperature and chemical potentials .
unfortunately , the most reliable techniques used at nonzero temperature and zero chemical potentials are generally not applicable at finite chemical potentials .
in particular , lattice simulations suffer from the so - called sign problem ..
Please generate the next two sentences of the article | this problem has not yet been solved explicitly .
however , some recent advances have allowed the study of the high temperature and low chemical potential part of the phase diagram . |
9,009 | Suppose that you have an abstract for a scientific paper: the solar corona , anomalously hot outer atmosphere of the sun , is traditionally described by magnetohydrodynamic , fluid - like approach . here
we review some recent developments when , instead , a full kinetic description is used .
it is shown that some of the main unsolved problems of solar physics , such as coronal heating and solar flare particle acceleration can be viewed in a new light when the small - scale , kinetic plasma description methods are used .
[ firstpage ] .
And you have already written the first three sentences of the full article: solar corona , a tenuous and very hot outer part of the solar atmosphere which sits on top of other layers ( photosphere , chromosphere , and the transition region ) can be seen either in white light observations during the solar eclipses ( because of @xmath0 times more flux of visible photospheric photons is otherwise outshining it ) or in extreme ultra - violet and x - ray observations from space ( because of atmospheric absorption of the short wavelength radiation ) .
@xcite describe the first successful observations of the green coronal line @xmath1 by w. harkness and independently by c.a .
young during the total solar eclipse of august 7 , 1869 ..
Please generate the next two sentences of the article | this `` new '' line was attributed to a new chemical element `` coronium '' .
it was easy to make such a mistake because just a year before , 1868 , during the solar eclipse @xcite discovered a prominent yellow line @xmath2 , which could not be ascribed to any known chemical element at the time . |
9,010 | Suppose that you have an abstract for a scientific paper: we revisit the question of the measured , unexpectedly large , heavy flavor suppression , @xmath0 , in nucleus - nucleus collisions at rhic and compare two new theoretical approaches to the @xmath1- and @xmath2-meson quenching . in the first model , radiative energy loss ,
collisional energy loss and heavy quark - resonance interactions are combined to evaluate the drag and diffusion coefficients in the quark - gluon plasma and the mixed phase .
these are applied in a relativistic fokker - planck equation to simulate the heavy @xmath3- and @xmath4-quark suppression rate and elliptic flow @xmath5 . in the second model , the fragmentation probability for heavy quarks and the medium - induced decay probability for heavy hadrons
are derived .
these are implemented in a set of coupled rate equations that describe the attenuation of the observable spectra from the collisional dissociation of heavy mesons in the qgp .
an improved description of the non - photonic electron @xmath6 at rhic can be obtained .
in contrast to previous results , the latter approach predicts suppression of @xmath2-mesons comparable to that of @xmath1-mesons at transverse momenta as low as @xmath7 gev . .
And you have already written the first three sentences of the full article: the detailed suppression pattern , @xmath6 , and elliptic flow , @xmath5 , of high - transverse - momentum hadrons is an important experimental signature of the quark - gluon plasma creation in heavy ion collisions @xcite .
jet quenching for light mesons , such as @xmath8 , @xmath9 and @xmath10 , at rhic is well explained by radiative energy loss calculations @xcite .
it also gives the dominant contribution to the azimuthal asymmetry of hard probes @xcite ..
Please generate the next two sentences of the article | in contrast , models @xcite with a physically reasonable set of qgp temperatures and densities , predict a qcd heavy - quark energy loss which is too small compared to the measured suppression of single non - photonic electrons @xcite .
therefore , it is critical to investigate new interaction mechanisms in the qgp that may be specific to heavy flavor @xcite . |
9,011 | Suppose that you have an abstract for a scientific paper: studies of the abundances of deuterium in different astrophysical sites are of fundamental importance to answering the question about how much deuterium was produced during big bang nucleosynthesis and what fraction of it was destroyed later . with this in mind , we used the interstellar medium absorption profile spectrograph ( imaps ) on the orfeus - spas ii mission to observe at a wavelength resolution of @xmath0 ( fwhm ) the l@xmath1 and l@xmath2 absorption features produced by interstellar atomic deuterium in the spectrum of @xmath1 ori a. a @xmath3 analysis indicated that @xmath4 at a 90% level of confidence , and the gas is at a temperature of about 6000k . in deriving these results , we created a template for the velocity profile defined by 7 different n i transitions recorded at a high signal - to - noise ratio .
extra free parameters in the analysis allowed for the additional uncertainties that could arise from various sources of systematic error . to derive a value for d / h
, we measured the l@xmath5 absorption features in 57 spectra of @xmath1 ori in the iue archive , with the objective of arriving at a more accurate h i column density than those reported by other investigators . from our measurement of @xmath6 , we found that @xmath7 ( 90% confidence ) .
systematic errors in the derivation of @xmath8(h i ) probably dominate over the very small formal error , but their relative value should be smaller than that for @xmath8(d i ) .
our result for d / h contrasts with the more general finding along other lines of sight that @xmath9 .
the underabundance of d toward @xmath1 ori a is not accompanied by an overabundance of n or o relative to h , as one might expect if the gas were subjected to more stellar processing than usual . .
And you have already written the first three sentences of the full article: the relative abundances of the light elements not only substantiate the standard interpretation for big bang nucleosynthesis ( bbn ) ( reeves et al . 1973 ; epstein , lattimer , & schramm 1976 ) , but they also hold the key for our determining the universal ratio of baryons to photons , commonly designated by the parameter @xmath10 ( boesgaard & steigman 1985 ; olive et al .
1990 ; smith , kawano , & malaney 1993 ) .
there has been considerable interest in measuring the abundance of deuterium , since its production was strongly regulated by photodestruction in the radiation bath during the bbn , making d / h a strong discriminant of @xmath10 ..
Please generate the next two sentences of the article | deuterium is also destroyed in stars . after having passed through one or more generations of stars , diffuse gases that we can observe
have probably had their deuterium abundances reduced to values below those that result from bbn . |
9,012 | Suppose that you have an abstract for a scientific paper: we compare calculations of jet quenching observables at @xmath0 = 2.76 atev to preliminary lhc data from weak - coupling pqcd and strong - coupling ads / cft drag energy loss models .
rigorously constrained to @xmath0 = 200 agev rhic @xmath1 suppression data and introducing no free parameters , the pqcd - based whdg model simultaneously describes qualitatively the suppression of light hadrons and quantitatively the azimuthal anisotropy ( over many centrality classes ) of light hadrons and the suppression of @xmath2 mesons at lhc .
the drag predictions shown here qualitatively constrained to rhic data compare poorly to the measured suppression of @xmath2 mesons , but the current experimental uncertainties are large
. the double ratio of @xmath2 to @xmath3 meson @xmath4 should provide a robust experimental measurement to distinguish between the very different assumptions of the strength of interactions in the qgp produced in heavy ion collisions ; i.e. , whether , from a jet quenching standpoint , the medium is either weakly- or strongly - coupled .
address = department of physics , university of cape town , private bag x3 , rondebosch 7701 , south africa .
And you have already written the first three sentences of the full article: since the discovery of a new phase of matter in @xmath0 = 200 agev heavy ion collisions @xcite , the goal of the high energy nuclear physics community is now the quantitative determination of the properties of the quark - gluon plasma ( qgp ) .
for instance , is the medium produced at rhic and lhc a weakly - coupled gas of the quarks and gluons of the quantum chromodynamics ( qcd ) lagrangian or perhaps a strongly coupled fluid made up of emergent collective degrees of freedom , and how does this description change as a function of @xmath0 , @xmath5 , and centrality ?
high momentum particles provide the most direct probe of the soft momentum modes present in the qgp created in heavy ion collisions ( see @xcite and references therein ) . extracting information about the fundamental properties of the qgp.
Please generate the next two sentences of the article | requires a comparison between theoretical calculations and experimental data . despite its great promise , to date
no one energy loss model has provided a consistent picture of the different relevant observables , such as and , as a function of particle mass , @xmath6 , centrality , and @xmath0 . |
9,013 | Suppose that you have an abstract for a scientific paper: we compute non - perturbatively the renormalization constants of composite operators for overlap fermions by using the regularization independent scheme .
the scaling behavior of the renormalization constants is investigated using the data from three lattices with similar physical volumes and different lattice spacings .
the approach of the renormalization constants to the continuum limit is explored . .
And you have already written the first three sentences of the full article: following previous papers @xcite in which we computed non - perturbatively the renormalization constants of composite operators with overlap fermions in quenched qcd , this paper will study the scaling behavior of the renormalization constants .
we adopt the non - perturbative renormalization method which was introduced by martinelli @xmath0 @xcite .
the method allows a full non - perturbative computation of the matrix elements of composite operators in the regularization independent ( ri ) scheme @xcite ( it is called the @xmath1 scheme by chetyrkin @xcite ) ..
Please generate the next two sentences of the article | the matching between the @xmath2 scheme and @xmath3 , which is intrinsically perturbative , is computed using continuum perturbation theory , which is well behaved .
the overlap fermion @xcite was proposed by narayanan and neuberger to evade the so called no - go " theorem @xcite . |
9,014 | Suppose that you have an abstract for a scientific paper: we define the excess degree @xmath0 of a @xmath1-polytope @xmath2 as @xmath3 , where @xmath4 and @xmath5 denote the number of vertices and edges , respectively .
we first prove that the excess degree of a @xmath1-polytope does not take every natural number : the smallest possible values are @xmath6 and @xmath7 , and the value @xmath8 only occurs when @xmath9 or 5 . on the other hand , for fixed @xmath1 ,
the number of values not taken by the excess degree is finite ( subject to the restraint that if @xmath1 is even , then the excess degree must be even ) . our study of the excess degree
is then applied in three different settings .
we show that polytopes with small excess ( i.e. , @xmath10 ) behave in a similar manner to simple polytopes in terms of minkowski decomposability : each such polytope is either decomposable or a pyramid , and their duals are always indecomposable .
( this is no longer true when @xmath11 . ) secondly , we characterise the decomposable @xmath1-polytopes with @xmath12 vertices .
and thirdly , we characterise all pairs @xmath13 for which there exists a 5-polytope with @xmath4 vertices and @xmath5 edges . .
And you have already written the first three sentences of the full article: this paper revolves around the excess degree of a @xmath1-dimensional polytope @xmath2 , or simply @xmath1-polytope , and some of its applications .
we define the _ excess degree _
@xmath0 , or simply excess , of a @xmath1-polytope @xmath2 as the sum of the excess degrees of its vertices , i.e. @xmath14 here as usual @xmath15 denotes the _ degree _ of a vertex @xmath16 , i.e the number of edges of @xmath2 incident with the vertex ; @xmath17 denotes the set of vertices of @xmath2 ; and @xmath4 and @xmath5 denote the number of vertices and edges of the polytope ..
Please generate the next two sentences of the article | our first substantial result , in 3 , is the excess theorem : the smallest values of the excess degree of @xmath1-polytopes are 0 and @xmath7 ; clearly a polytope is simple if , and only if , its excess degree is 0 .
note that for fixed @xmath1 and @xmath4 , the possible values of the excess are either all even or all odd . |
9,015 | Suppose that you have an abstract for a scientific paper: we study the kinetics of _ infiltration _ in which contaminant particles , which are suspended in a flowing carrier fluid , penetrate a porous medium .
the progress of the `` invader '' particles is impeded by their trapping on active `` defender '' sites which are on the surfaces of the medium .
as the defenders are used up , the invader penetrates further and ultimately breaks through .
we study this process in the regime where the particles are much smaller than the pores so that the permeability change due to trapping is negligible .
we develop a family of microscopic models of increasing realism to determine the propagation velocity of the invasion front , as well as the shapes of the invader and defender profiles .
the predictions of our model agree qualitatively with experimental results on breakthrough times and the time dependence of the invader concentration at the output .
our results also provide practical guidelines for improving the design of deep bed filters in which infiltration is the primary separation mechanism . 2 .
And you have already written the first three sentences of the full article: in depth filtration , suspended particles in a fluid are removed during their passage through a porous medium@xcite .
the basic dynamics of depth filtration is determined primarily by the pore structure of the filter , the particle size distribution , and by various physicochemical and hydrodynamic details .
if the particle size is larger than the typical pore size , particles get stuck relatively quickly ..
Please generate the next two sentences of the article | the permeability of the filter decreases steadily during this process and drops to zero when clogging is reached .
this process is often referred to as sieving , or straining@xcite . |
9,016 | Suppose that you have an abstract for a scientific paper: when thermal energies are weak , two dimensional lamellar structures confined on a curved substrate display complex patterns arising from the competition between layer bending and compression in the presence of geometric constraints .
we present broad design principles to engineer the geometry of the underlying substrate so that a desired lamellar pattern can be obtained by self - assembly .
two distinct physical effects are identified as key factors that contribute to the interaction between the shape of the underlying surface and the resulting lamellar morphology .
the first is a local ordering field for the direction of each individual layer which tends to minimize its curvature with respect to the three - dimensional embedding .
the second is a non - local effect controlled by the intrinsic geometry of the surface that forces the normals to the ( nearly incompressible ) layers to lie on geodesics , leading to caustic formation as in optics . as a result ,
different surface morphologies with predominantly positive or negative gaussian curvature can act as converging or diverging lenses respectively . by combining these ingredients , as one would with different optical elements ,
complex lamellar morphologies can be obtained .
this smectic optometry enables the manipulation of lamellar configurations for the design of novel materials . .
And you have already written the first three sentences of the full article: though many are taught that there are merely three phases of matter , _ solid , liquid , _ and _ gas _ , the understanding of broken symmetries , nambu - goldstone modes @xcite , and the anderson - higgs - kibble @xcite mechanism allows prediction , control , and elucidation of other novel forms of matter .
liquid crystalline phases interpolate between the simple forms of matter sketched above .
the nematic has partially broken rotational invariance @xcite , the smectic phase has broken one - dimensional translation invariance @xcite , and the hexatic phase @xcite has broken two - dimensional rotational invariance ..
Please generate the next two sentences of the article | these materials not only afford a deeper understanding of condensed matter , they ( and their lyotropic cousins , diblock copolymers @xcite ) , are also of great technological interest , from displays to coatings , from drug delivery to hybrid materials .
technological applications provide challenges for the theorist and , in particular , pose problems with imperfect boundary conditions and geometries . in this paper |
9,017 | Suppose that you have an abstract for a scientific paper: we applied a mean - field approach associated to monte carlo simulations in order to study the spin-1 ferromagnetic blume - capel model in the square and the linear lattice .
this new technique , which we call mft - mc , determines the molecular field as the magnetization response of a monte carlo simulation .
the resulting phase diagram is qualitatively correct , in contrast to effective - field approximations , in which the first - order line is not perpendicular to the anisotropy axis at low temperatures .
thermodynamic quantities , as the entropy and the specific heat curves can be obtained so as to analyze the nature of the phase transition points .
also , the possibility of using larger sizes constitutes an improvement regarding other mean - field approximations that use clusters .
* pacs numbers * : 64.60.ak ; 64.60.fr ; 68.35.rh .
And you have already written the first three sentences of the full article: in general , many - body systems with interactions are very difficult to solve exactly . a way to overcome this difficulty is by approaching the many - body problem by a one - body problem , in which a mean - field replaces the interactions affecting the body .
this idea is applied to the ferromagnetic ising model ( see reference @xcite ) . in the most simple mean - field approach ,
the nearest - neighbor interactions affecting each spin @xmath0 are replaced in such a way that @xmath0 now interacts with an effective field given by @xmath1 , where @xmath2 is the coordination number , @xmath3 the exchange constant , and @xmath4 is the thermal average of the spin @xmath5 ..
Please generate the next two sentences of the article | this is the so called `` weiss mean - field approach '' @xcite .
nevertheless , it neglects the spin correlations , and it leads the transition temperature @xmath6 as well as the values of the critical exponents away from the exact values ( @xmath7 , for all dimensions ) . |
9,018 | Suppose that you have an abstract for a scientific paper: we propose a general framework for parameter - free identification of a class of dynamical systems . here , the propagator is approximated in terms of an arbitrary function of the state , in contrast to a polynomial or galerkin expansion used in traditional approaches .
the proposed formulation relies on variational data assimilation using measurement data combined with assumptions on the smoothness of the propagator .
this approach is illustrated using a generalized dynamic model describing oscillatory transients from an unstable fixed point to a stable limit cycle and arising in nonlinear stability analysis as an example .
this 3-state model comprises an evolution equation for the dominant oscillation and an algebraic manifold for the low- and high - frequency components in an autonomous descriptor system .
the proposed optimal model identification technique employs mode amplitudes of the transient vortex shedding in a cylinder wake flow as example measurements .
the reconstruction obtained with our technique features distinct and systematic improvements over the well - known mean - field ( landau ) model of the hopf bifurcation .
the computational aspect of the identification method is thoroughly validated showing that good reconstructions can also be obtained in the absence of of accurate initial approximations .
* keywords : * hydrodynamic instabilities , reduced - order models , mean - field models , variational data assimilation , adjoint - based optimization , * ams subject classifications : * 93a30 , 65k10 , 76d25 .
And you have already written the first three sentences of the full article: in this study we consider the problem of parameter - free identification of a class of dynamical systems . the approach we propose is derived from a general method for the reconstruction of the constitutive relations in systems described by partial differential equations ( pdes ) which was initially introduced in @xcite and further developed in @xcite , see also @xcite
the idea is that , given an autonomous evolution equation @xmath0 for some quantity @xmath1 ( defined in a finite or infinite dimension with @xmath2 denoting time ) , one seeks to optimally reconstruct the flux function @xmath3 , so that the system outputs best match , in a suitably defined sense , with the measurements available .
as shown schematically in figure [ fig : f ] , the originality of this approach is that the function @xmath3 is reconstructed directly as a _ continuous _ object , rather than employing a truncated polynomial or other galerkin expansion . in @xcite.
Please generate the next two sentences of the article | we reviewed the mathematical foundations and some computational aspects of this approach applied to the reconstruction of state - dependent transport coefficients in a class of systems described by pdes . in the present investigation we adapt this method to the problem of identification of the propagator function @xmath4 , @xmath5^t$ ] , in a finite - dimensional dynamical system @xmath6 with the state vector @xmath7^t \in \rr^n$ ] .
to fix attention , instead of working with an abstract formulation , we will focus on a specific problem concerning a three - dimensional ( @xmath8 ) model characterized by oscillatory dynamics with a stable limit cycle . in many real - life physical problems with infinite - dimensional state spaces and evolution described by pdes such systems |
9,019 | Suppose that you have an abstract for a scientific paper: we have systematically investigated the _ asca _
spectra of 12 early type galaxies .
this paper presents the global spectral properties of these systems based on a larger sample than in any previous _ asca _ study .
the x - ray spectra were uniformly fitted by a two - component model consisting of hard x - rays from thermal emission with a temperature of about 10 kev or from a power - law with index 1.8 , plus soft x - rays from a thin thermal plasma with temperature ranging from 0.3 to 1 kev .
the x - ray luminosities of the hard component are found to be proportional to the blue band luminosities , while those of the soft component show large scatter with no clear correlation .
the metal abundances determined from the soft component are systematically lower than solar , with a mean value of about 0.3 solar .
we examine the relationships between the temperature and volume emission measure , and between the gas temperature and the stellar velocity dispersion .
the volume emission measures for early type galaxies plotted as a function of the gas temperature are well below the extrapolated line found in clusters of galaxies , indicating that early type galaxies are relatively gas poor compared with galaxy clusters .
the ratio of the stellar kinetic energy per unit mass to the thermal energy of the hot gas per unit mass ( @xmath0 ) is less than unity .
we found no systematic relationship between x - ray properties and environment , suggesting that the interaction between interstellar matter and the intracluster medium is not strong . .
And you have already written the first three sentences of the full article: the _ einstein _ satellite discovered x - ray emitting gas halos around luminous early type galaxies ( eg .
forman , jones , & tucker 1985 ) , forcing the rejection of previous assumptions that elliptical galaxies are gas poor systems .
the x - ray surface brightness distribution was found to closely follow the optical image ( trinchieri , fabbiano , & canizares 1986 ) ; however the x - ray luminosity , and hence the mass of the hot gas , showed large scatter from galaxy to galaxy ( eg ..
Please generate the next two sentences of the article | canizares , fabbiano , & trinchieri 1987 ) .
the estimated cooling time of the hot gas is less than the hubble time ( trinchieri et al . |
9,020 | Suppose that you have an abstract for a scientific paper: the non - linear transformations incurred by the rays in an optical system can be suitably described by matrices to any desired order of approximation . in systems composed of uniform refractive index elements
, each individual ray refraction or translation has an associated matrix and a succession of transformations correspond to the product of the respective matrices .
this paper describes a general method to find the matrix coefficients for translation and surface refraction irrespective of the surface shape or the order of approximation .
the choice of coordinates is unusual as the orientation of the ray is characterised by the direction cosines , rather than slopes ; this is shown to greatly simplify and generalise coefficient calculation .
two examples are shown in order to demonstrate the power of the method : the first is the determination of seventh order coefficients for spherical surfaces and the second is the determination of third order coefficients for a toroidal surface . .
And you have already written the first three sentences of the full article: optics , aberration , matrices .
an optical system can be effectively modelled in paraxial approximation by a product of @xmath0 matrices , each representing one elementary transformation of the light rays @xcite ; the elementary transformations are either translations of the ray in homogeneous media or the effects of surfaces separating different media .
a more accurate approach implies the consideration of higher order terms but the fact that snell s law makes use of the sine function rules out the terms of even order ; as a consequence , when one wants to improve on the paraxial approximation , one has to consider third order terms ..
Please generate the next two sentences of the article | aberrations have already been studied extensively @xcite but work is still going on in order to design symbolic models of optical systems that computers can use for optimisation purposes and humans can look at to gain a better understanding of systems performance . the matrix theory has been extended to deal with higher order terms @xcite through the use of a vector basis that incorporates two position and two orientation coordinates as well as all their third or higher order monomials , increasing the overall dimension which becomes 24 for third order approximation .
it is possible to apply axis symmetry to reduce the matrix dimension through the use of complex coordinates and their higher order monomials ; for instance , in third order the matrices to be considered for axis - symmetric systems are @xmath1 @xcite . |
9,021 | Suppose that you have an abstract for a scientific paper: many asteroids in the main and trans - neptunian belts are trapped in mean motion resonances with jupiter and neptune , respectively . as a side effect
, they experience accidental commensurabilities among themselves .
these commensurabilities define characteristic patterns that can be used to trace the source of the observed resonant behaviour . here , we explore systematically the existence of commensurabilities between the known etnos using their heliocentric and barycentric semimajor axes , their uncertainties , and monte carlo techniques . we find that the commensurability patterns present in the known etno population resemble those found in the main and trans - neptunian belts .
although based on small number statistics , such patterns can only be properly explained if most , if not all , of the known etnos are subjected to the resonant gravitational perturbations of yet undetected trans - plutonian planets .
we show explicitly that some of the statistically significant commensurabilities are compatible with the planet nine hypothesis ; in particular , a number of objects may be trapped in the 5:3 and 3:1 mean motion resonances with a putative planet nine with semimajor axis @xmath0700 au . [ firstpage ] methods : statistical celestial mechanics kuiper belt : general minor planets , asteroids : general oort cloud planets and satellites : general . .
And you have already written the first three sentences of the full article: in trujillo & sheppard ( 2014 ) , the extreme trans - neptunian objects or etnos are defined as asteroids with heliocentric semimajor axis greater than 150 au and perihelion greater than 30 au .
there are at present 16 known etnos ( see tables [ helio ] and [ bary ] for relevant data ) ; they exhibit clustering in the values of their argument of perihelion ( trujillo & sheppard 2014 ) , longitude of the ascending node ( batygin & brown 2016 ) , eccentricity and inclination ( de la fuente marcos & de la fuente marcos 2014 , 2016 ) .
the analysis in de la fuente marcos & de la fuente marcos ( 2014 ) has shown that the clustering in eccentricity ( @xmath1 about 0.81 ) can be due to a selection effect , but this can not be the case of the ones found in inclination ( @xmath2 about 20 ) , longitude of the ascending node ( @xmath3 about 134 ) , and argument of perihelion ( @xmath4 about @xmath526 ) ..
Please generate the next two sentences of the article | these patterns could be induced by the gravitational perturbation from one ( trujillo & sheppard 2014 ; gomes , soares & brasser 2015 ; batygin & brown 2016 ) or more ( de la fuente marcos & de la fuente marcos 2014 ; de la fuente marcos , de la fuente marcos & aarseth 2015 ) , yet to be discovered , trans - plutonian planets .
malhotra , volk & wang ( 2016 ) have pointed out that the four etnos with the longest orbital periods ( see table [ bary ] ) have simple numerical relationships between periods . |
9,022 | Suppose that you have an abstract for a scientific paper: in the standard model ( sm ) , lepton flavor violating ( lfv ) higgs decay is absent at renormalizable level and thus it is a good probe to new physics . in this article
we study a type of new physics that could lead to large lfv higgs decay , i.e. , a lepton - flavored dark matter ( dm ) model which is specified by a majorana dm and scalar lepton mediators .
different from other similar models with similar setup , we introduce both left - handed and right - handed scalar leptons . they allow large lfv higgs decay and thus may explain the tentative br@xmath0 experimental results from the lhc .
in particular , we find that the stringent bound from @xmath1 can be naturally evaded .
one reason , among others , is a large chirality violation in the mediator sector .
aspects of relic density and especially radiative direct detection of the leptonic dm are also investigated , stressing the difference from previous lepton - flavored dm models . .
And you have already written the first three sentences of the full article: after the discovery of standard model ( sm ) higgs - like boson , the next step is to measure its couplings precisely to see possible deviation from the sm and thus to search for new physics .
the yukawa couplings between higgs boson and charged leptons that cause lepton flavor violation ( lfv ) are of particular interest , because in the sm they are absent at tree level and highly suppressed at loop levels , and thus are sensitive to new physics . as a matter of fact , in most of models that address neutrino masses and oscillations ,
lfv is well expected and has already been observed in neutrino oscillations described by the pmns matrix . moreover , although charged lepton flavor violation ( clfv ) has not been observed yet , in general those models should leave measurable signals in processes like @xmath2 , @xmath3 , etc ..
Please generate the next two sentences of the article | a lot of efforts have been devoted to searching for clfv and the null results impose very strong bounds on the magnitude of lfv @xcite . searching for lfv higgs decays
@xcite receives special attention in the lhc era @xcite . |
9,023 | Suppose that you have an abstract for a scientific paper: a generalisation of the cassels and greub - reinboldt inequalities in complex or real inner product spaces and applications for isotonic linear functionals , integrals and sequences are provided . .
And you have already written the first three sentences of the full article: the following result was proved by j.w.s .
cassels in 1951 ( see appendix 1 of @xcite ) .
[ t1.1]let @xmath0 @xmath1 be sequences of positive real numbers and @xmath2 a sequence of nonnegative real numbers ..
Please generate the next two sentences of the article | suppose that@xmath3then one has the inequality@xmath4the equality holds in ( [ 1.2 ] ) when @xmath5 @xmath6 @xmath7 @xmath8 and @xmath9 if one assumes that @xmath10 and @xmath11 for each @xmath12 then by ( [ 2.2 ] ) we may obtain greub - reinboldt s inequality @xcite@xmath13the following unweighted cassels inequality also holds@xmath14provided @xmath15 and @xmath16 satisfy ( 1.1 ) .
this inequality will produce the well known plya - szeg inequality @xcite , @xcite:@xmath17provided @xmath10 and @xmath18 for each @xmath19 in @xcite , c.p . |
9,024 | Suppose that you have an abstract for a scientific paper: we have developed a flexible framework for constructing jastrow factors which allows for the introduction of terms involving arbitrary numbers of particles .
the use of various three- and four - body jastrow terms in quantum monte carlo calculations is investigated , including a four - body van der waals - like term , and anisotropic terms .
we have tested these jastrow factors on one- and two - dimensional homogeneous electron gases , the be , b , and o atoms , and the beh , h@xmath0o , n@xmath0 , and h@xmath0 molecules .
our optimized jastrow factors retrieve more than 90% of the fixed - node diffusion monte carlo correlation energy in variational monte carlo for each system studied . .
And you have already written the first three sentences of the full article: the variational and diffusion quantum monte carlo methods ( vmc and dmc ) are zero - temperature stochastic techniques for evaluating the expectation values of time - independent operators @xcite .
these methods are particularly well suited for calculating the ground - state energies of large assemblies of interacting quantum particles .
the central object is an approximate trial wave function whose accuracy controls the computed energy and the intrinsic statistical fluctuations in the calculations ..
Please generate the next two sentences of the article | it is therefore of particular importance to develop accurate trial wave functions .
expectation values in vmc are evaluated using importance - sampled monte carlo integration . in dmc |
9,025 | Suppose that you have an abstract for a scientific paper: full - rate stbc ( space - time block codes ) with non - vanishing determinants achieve the optimal diversity - multiplexing tradeoff but incur high decoding complexity . to permit fast decoding , sezginer , sari and biglieri proposed an stbc structure with special qr decomposition characteristics . in this paper
, we adopt a simplified form of this fast - decodable code structure and present a new way to optimize the code analytically .
we show that the signal constellation topology ( such as qam , apsk , or psk ) has a critical impact on the existence of non - vanishing determinants of the full - rate stbc . in particular
, we show for the first time that , in order for apsk - stbc to achieve non - vanishing determinant , an apsk constellation topology with constellation points lying on square grid and ring radius @xmath0 needs to be used . for signal constellations with vanishing determinants
, we present a methodology to analytically optimize the full - rate stbc at specific constellation dimension . .
And you have already written the first three sentences of the full article: multi - output ( mimo ) systems can be designed to provide two types of gains : transmit diversity gain and spatial multiplexing gain@xcite .
the full - rate full - diversity space - time block codes ( stbc ) in @xcite can achieve both for 2@xmath12 mimo systems .
recently , a fast - decodable full - rate stbc is proposed by s. sezginer , h. sari and e. biglieri @xcite@xcite : @xmath2 \end{split}\ ] ] where @xmath3 with @xmath4 are information symbols , @xmath5 are design coefficients and @xmath6 denotes the complex conjugate . due to its code structure in ( [ bostbc ] ).
Please generate the next two sentences of the article | , @xmath7 has additional zero entries appearing in the upper - triangular matrix after qr decomposition of the equivalent channel matrix , thus making it fast - decodable @xcite@xcite .
it is shown in @xcite that the code structure ( [ bostbc ] ) after optimizing for non - vanishing determinant can be rewritten with a single design coefficient . |
9,026 | Suppose that you have an abstract for a scientific paper: a novel approach for dealing with censored competing risks regression data is proposed .
this is implemented by a mixture of accelerated failure time ( aft ) models for a competing risks scenario within a cluster - weighted modelling ( cwm ) framework .
specifically , we make use of the log - normal aft model here but any commonly used aft model can be utilized . the alternating expectation conditional maximization algorithm ( aecm )
is used for parameter estimation and bootstrapping for standard error estimation .
finally , we present our results on some simulated and real competing risks data . .
And you have already written the first three sentences of the full article: survival techniques are useful in situations where regular regression procedures are inadequate . for instance , where the probability of survival past a certain time is of more interest than the expected time of survival , survival techniques are more appropriate .
the same holds true when there are censored data .
censored data may arise due to partial follow - up ( until a specific time ) , loss to follow - up , or a subject dropping out of a study ..
Please generate the next two sentences of the article | attrition is quite common in medical studies where a subject is followed to a particular event of interest . in such cases ,
the status of these subjects with respect to the event of interest is only known up to a particular time point . |
9,027 | Suppose that you have an abstract for a scientific paper: with x - ray absorption spectroscopy and polarized neutron reflectometry we studied how the magnetic proximity effect at the interface between the cuprate high-@xmath0 superconductor @xmath1 ( ybco ) and the ferromagnet @xmath2 ( lcmo ) is related to the electronic and magnetic properties of the lcmo layers .
in particular , we explored how the magnitude of the ferromagnetic cu moment on the ybco side depends on the strength of the antiferromagnetic ( af ) exchange coupling with the mn moment on the lcmo side .
we found that the cu moment remains sizeable if the af coupling with the mn moments is strongly reduced or even entirely suppressed .
the ferromagnetic order of the cu moments thus seems to be intrinsic to the interfacial cuo@xmath3 planes and related to a weakly ferromagnetic intra - planar exchange interaction .
the latter is discussed in terms of the partial occupation of the cu @xmath4 orbitals , which occurs in the context of the so - called orbital reconstruction of the interfacial cu ions . .
And you have already written the first three sentences of the full article: the physical properties of interfaces between complex oxides are of great current interest @xcite .
a prominent example is the interface between the two band insulators @xmath5 and @xmath6 at which highly mobile carriers are confined and give rise to electronic and superconducting phenomena that can be tuned with a gate voltage @xcite .
another interesting example involves the magnetic proximity effect ( mpe ) at the interface between the cuprate high-@xmath0 superconductor ( sc ) @xmath1 ( ybco ) and ferromagnet ( fm ) @xmath2 ( lcmo ) @xcite ..
Please generate the next two sentences of the article | with polarized neutron reflectometry ( pnr ) it was found that , in the vicinity of the interface , the fm order of the mn moments is strongly suppressed @xcite .
this phenomenon has been discussed in terms of a _ _ or a _ _ . |
9,028 | Suppose that you have an abstract for a scientific paper: non - decoupling d - terms are an attractive possibility to enhance the tree - level mass of the standard model like higgs boson in supersymmetric models .
we discuss here for the case of a new abelian gauge group two effects usually neglected in literature : ( i ) the size of the additional radiative corrections to the higgs mass due to the presence of the new gauge coupling , and ( ii ) the impact of gauge kinetic mixing .
it is shown that both effects reduce to some extent the positive effect of the non - decoupling d - terms on the higgs mass .
cern - th-2016 - 061 .
And you have already written the first three sentences of the full article: the discovery of the higgs boson at the large hadron collider ( lhc ) @xcite completes not only the standard model ( sm ) of particle physics , but gives also new constraints on any extension of it .
the most studied extension of the sm to date is supersymmetry ( susy ) , see ref .
@xcite and references therein ..
Please generate the next two sentences of the article | however , the minimal - supersymmetric standard model ( mssm ) is facing increasing pressure over the last few years .
one of the reasons is the measured higgs mass of 125 gev which is not trivial to accommodate in the mssm . |
9,029 | Suppose that you have an abstract for a scientific paper: a large lepton asymmetry could be generated in the early universe by oscillations of active to sterile neutrinos with a small mixing angle @xmath0 .
the final order of magnitude of the lepton asymmetry @xmath1 is mainly determined by its growth in the last stage of evolution when the msw resonance dominates the kinetic equations . in this paper
we present a simple way of calculating the maximum possible lepton asymmetry which can be created .
our results are in good agreement to previous calculations .
furthermore , we find that the growth of asymmetry does not obey any particular power law .
we find that the maximum possible asymmetry at the freeze - out of the @xmath2/@xmath3 ratio at @xmath4 strongly depends on the mass - squared difference @xmath5 : the asymmetry is negligible for @xmath6 and reaches asymptotically large values for @xmath7 .
= -1.0 cm # 1#2 mpi pht/2000 - 37 + .06 in * maximum lepton asymmetry from active sterile neutrino oscillations in the early universe . * + * r. buras * + _ max - planck - institut fr physik ( werner - heisenberg - institut ) + fhringer ring 6 , 80805 mnchen , germany _ + * d.v .
semikoz * + _ max - planck - institut fr physik ( werner - heisenberg - institut ) + fhringer ring 6 , 80805 mnchen , germany + and + institute of nuclear research of the russian academy of sciences + 60th october anniversary prospect 7a , moscow 117312 , russia _ + .
And you have already written the first three sentences of the full article: neutrino oscillations between muon and tau neutrinos , which were found recently in the super - kamiokande experiment @xcite , prove the existence of neutrino masses .
this finding does not spoil the standard big bang nucleosynthesis ( bbn ) picture because experimentally interesting neutrino masses for all three flavors @xmath8 , @xmath9 , are small @xmath10 ev , in comparison to typical bbn temperatures @xmath11 mev . as for oscillations between active flavors ,
these do not play any role in bbn because all active flavors are equally populated ..
Please generate the next two sentences of the article | however , if sterile neutrinos exist , oscillations between active and sterile states could have significant consequences for bbn .
one possibility is that the total energy density of the universe is changed due to excited sterile neutrinos ; together with a recent analysis of observational data @xcite , which claims that the effective number of neutrinos can not exceed @xmath12 , this effect can be used to exclude some region of the @xmath13 parameter plane e.g. for heavy sterile neutrinos @xcite . |
9,030 | Suppose that you have an abstract for a scientific paper: the distribution function of the free energy fluctuations in one - dimensional directed polymers with free boundary conditions is derived by mapping the replicated problem to the @xmath0-particle quantum boson system with attractive interactions .
it is shown that in the thermodynamic limit this function is described by the universal tracy - widom distribution of the gaussian orthogonal ensemble . .
And you have already written the first three sentences of the full article: directed polymers in a quenched random potential have been the subject of intense investigations during the past two decades ( see e.g. @xcite ) . in the one - dimensional case we deal with an elastic string directed along the @xmath1-axis within an interval
@xmath2 $ ] .
randomness enters the problem through a disorder potential @xmath3 $ ] , which competes against the elastic energy ..
Please generate the next two sentences of the article | the problem is defined by the hamiltonian @xmath4 = \int_{0}^{t } d\tau \bigl\{\frac{1}{2 } \bigl[\partial_\tau \phi(\tau)\bigr]^2 + v[\phi(\tau),\tau]\bigr\};\ ] ] where the disorder potential @xmath5 $ ] is gaussian distributed with a zero mean @xmath6 and the @xmath7-correlations : @xmath8 here the parameter @xmath9 describes the strength of the disorder .
note that such system is equivalent to the problem of the kardar - parisi - zang ( kpz ) equation describing the growth in time of an interface in the presence of noise @xcite . in what follows we consider the problem in which the polymer is fixed at the origin , @xmath10 and it is free at @xmath11 . |
9,031 | Suppose that you have an abstract for a scientific paper: the properties of the bright and energetic type ic sn 1997ef are investigated using a monte carlo spectrum synthesis code .
analysis of the earliest spectra is used to determine the time of outburst .
the changing features of the spectrum and the light curve are used to probe the ejecta and to determine their composition , verifying the results of explosion calculations . since synthetic spectra computed using our best explosion model co100 are only moderately good reproductions of the observations , the inverse approach is adopted , and a density structure is derived by demanding that it gives the best possible fit to the observed spectrum at every epoch analysed .
it is found that the density structure of model co100 is adequate at intermediate velocities ( 500025000 km s@xmath0 ) , but that a slower density decline ( @xmath1 ) is required to obtain the extensive line blending at high velocities ( 2500050000 km s@xmath0 ) which is the characterising feature of this and other energetic type ic supernovae .
also , the inner ` hole ' in the density predicted by the model is found not to be compatible with the observed evolution of the spectrum , which reaches very low photospheric velocities at epochs of about 2 months .
the ` best fit ' density distribution results in somewhat different parameters for the sn , namely an ejecta mass of 9.6m@xmath2 ( v. 7.6m@xmath2 in co100 ) and an explosion kinetic energy of @xmath3erg ( v. @xmath4erg in co100 ) .
this revised value of the kinetic energy brings sn 1997ef closer to the value for the ` prototypical ' type ic ` hypernova ' sn 1998bw .
the abundance distribution of model co100 is found to hold well .
the modified density structure is used to compute a synthetic light curve , which is found to agree very well with the observed bolometric light curve around maximum .
the amount of radioactive @xmath5ni produced by the sn is confirmed at 0.13m@xmath2 . in the context of an axisymmetric explosion , a somewhat smaller kinetic energy than....
And you have already written the first three sentences of the full article: sn 1997ef in ugc4107 was recognised as a peculiar and interesting object as soon as its first spectra were taken by the harvard - cfa team ( garnavich et al . 1997a , b , c ) .
the spectra displayed very broad features , quite unlike those of any other sn known to date , so that it was not even clear whether what was observed was an absorption or an emission spectrum .
continued observation revealed a light curve typical of a sn deriving from a compact object ( a sn ia or a sn ic ) , but much broader than the templates for both of these classes ..
Please generate the next two sentences of the article | later spectra showed more resolved spectral lines , clarifying that the broad features were actually very extended absorption blends , and that the sn was therefore in the photospheric epoch .
lines of ca ii , o i and fe ii were strong , and the si ii 6347 , 6371 line appeared to be comparatively weak , so the sn was classified as type ic , as also supported by the overall similarity with the spectra of other sne ic such as sn 1994i ( filippenko 1997 ; millard et al . |
9,032 | Suppose that you have an abstract for a scientific paper: the semi - analytic theory of tidal shocks proves to be a powerful tool to study tidal interactions of star clusters and satellite galaxies with their massive hosts .
new models of the globular cluster evolution employ a combination of analytic estimates , solutions of the fokker - planck equation and direct n - body simulations .
the models predict large destruction rates for the galactic globular clusters .
those on the highly eccentric orbits around the galactic center are much more likely to be disrupted than the ones on nearly circular orbits .
the destruction rates are largely increased near the bulge .
disruption of the low - mass clusters changes the luminosity function of the globular cluster system , shifting the peak of the luminosity function to the brighter end . .
And you have already written the first three sentences of the full article: dynamical evolution of globular clusters is strongly affected by gravitational tidal shocks .
when the clusters cross the disk of the galaxy they experience disk shocking ; when the clusters pass near the galactic center , they experience bulge shocking .
the effects of the tidal shocks depend on the density of the background stars and are especially pronounced in the inner regions of the galaxy ..
Please generate the next two sentences of the article | tidal shocks increase the energy of random motion of stars , reduce the binding energy of the cluster , accelerate core collapse , and lead to the faster overall evolution and destruction of globular clusters ( for example , spitzer 1987 ; weinberg 1994 ; murali & weinberg 1997a , b , c ; gnedin & ostriker 1997a ) .
we calculate the rate of destruction of globular clusters as a result of various physical processes : two - body relaxation , evaporation of stars through the tidal boundary , disk shocking and bulge shocking ( gnedin & ostriker 1997a ) . |
9,033 | Suppose that you have an abstract for a scientific paper: before a cell divides into two daughter cells , chromosomes are replicated resulting in two sister chromosomes embracing each other .
each sister chromosome is bound to a separate proteinous structure , called kinetochore ( kt ) , that captures the tip of a filamentous protein , called microtubule ( mt ) .
two oppositely oriented mts pull the two kts attached to two sister chromosomes thereby pulling the two sisters away from each other . here
we theoretically study an even simpler system , namely an isolated kt coupled to a single mt ; this system mimics an _ in - vitro _ experiment where a single kt - mt attachment is reconstituted using purified extracts from budding yeast .
our models not only account for the experimentally observed `` catch - bond - like '' behavior of the kt - mt coupling , but also make new predictions on the probability distribution of the lifetimes of the attachments . in principle , our new predictions can be tested by analyzing the data collected in the _ in - vitro _
experiments provided the experiment is repeated sufficiently large number of times .
our theory provides a deep insight into the effects of ( a ) size , ( b ) energetics , and ( c ) stochastic kinetics of the kt - mt coupling on the distribution of the lifetimes of these attachments . .
And you have already written the first three sentences of the full article: chromosomes , the genetic material of a cell , are duplicated and properly segregated before the cell divides into two daughter cells @xcite .
each of the sister chromatids , that result from chromosome replication , is bound to a proteinous structure , called kinetochore ( kt ) that , in turn , is coupled to the plus ends of stiff polar filaments called microtubules ( mt ) @xcite .
the negative ends of these mts are located at the poles of the fusiform structure , called mitotic spindle @xcite ..
Please generate the next two sentences of the article | the process of chromosome segregation , called mitosis @xcite , is carried out in eukaryotic cells by the dynamic mitotic spindle which is self - organized from its components for this purpose .
there are strong indications that molecular motors @xcite are located at the kt - mt interface ( though not in all eukaryotes ) ; these motor proteins , which are capable of generating force by hydrolyzing atp , are believed to generate poleward force or anti - poleward force depending on the family to which they belong . |
9,034 | Suppose that you have an abstract for a scientific paper: we predict heating of quasiparticles driven by order parameter oscillations in the resistive state of short superconducting microbridges .
the finite relaxation time of the magnitude of the order parameter @xmath0 and the dependence of the spectral functions both on @xmath0 and the supervelocity @xmath1 are the origin of this effect .
our result is opposite to those of aslamazov and larkin ( zh
. eks .
. fiz . * 70 * , 1340 ( 1976 ) ) and schmid , schn and tinkham ( phys .
rev .
b * 21 * 5076 ( 1980 ) ) where cooling of quasiparticles was found . .
And you have already written the first three sentences of the full article: we study theoretically the resistive state in short superconducting microbridges ( with length l less than the coherence length @xmath2 ) at temperatures close to the critical one .
this subject was widely discussed and studied in the 70-ies of last century ( for review see @xcite ) and has regained renewed interest recently ( see for example refs .
interesting phenomena occurring in such a system , and which are still not completely understood , are : i ) the hysteresis of current - voltage ( iv ) characteristics at relatively low temperatures @xcite and ii ) the foot-like ( sometimes also called shoulder-like - see ref ..
Please generate the next two sentences of the article | @xcite ) feature in the iv characteristics observed experimentally mainly in tin microbridges at low voltages and at temperatures close to @xmath3 @xcite ( see also @xcite ) .
the hysteresis is usually explained by joule heating while for the foot-like structure several theories were proposed @xcite that are based on the idea that the quasiparticle distribution function is out of equilibrium ( overcooled ) as a consequence of the variation in time of the magnitude of the superconducting order parameter @xmath4 in the superconducting microbridge . |
9,035 | Suppose that you have an abstract for a scientific paper: we combine _ spitzer _ 24@xmath0 observations with data from the combo-17 survey for @xmath115,000 @xmath2 galaxies to determine how the average star formation rates ( sfr ) have evolved for galaxy sub - populations of different stellar masses . in the determination of @xmath3sfr@xmath4
we consider both the ultraviolet ( uv ) and the infrared ( ir ) luminosities , and account for the contributions of galaxies that are individually undetected at 24@xmath0 through image stacking .
for all redshifts we find that higher - mass galaxies have substantially lower specific sfr , @xmath3sfr@xmath4/@xmath3m@xmath5@xmath4 , than lower - mass ones .
however , we find the striking result that the rate of decline in cosmic sfr with redshift is nearly the same for massive and low - mass galaxies , i.e. _ not _ a strong function of stellar mass .
this analysis confirms one version of what has been referred to as ` downsizing ' , namely that the epoch of major mass build - up in massive galaxies is substantially earlier than the epoch of mass build - up in low - mass galaxies .
yet it shows that star formation activity is _ not _ becoming increasingly limited to low - mass galaxies towards the present epoch .
we argue that this suggests that heating by agn - powered radio jets is not the dominant mechanism responsible for the decline in cosmic sfr since @xmath6 , which is borne out by comparison with semi - analytic models that include this effect . .
And you have already written the first three sentences of the full article: a key observable statistic that describes the evolution of the galaxy population is the average sfr as a function of epoch and of galaxy stellar mass . over the last decade
, much progress has been made towards delineating , and in part understanding , the relationship between star formation history and stellar mass .
`` archaeological '' studies of present - day galaxies demonstrate a strong correlation between star formation history and present - day stellar mass in the sense that the bulk of stars now in massive galaxies must have formed at earlier epochs than stars now in less massive galaxies ( e.g. , * ? ? ?.
Please generate the next two sentences of the article | * ; * ? ? ?
* ; * ? ? ? |
9,036 | Suppose that you have an abstract for a scientific paper: from the beginning of his research , the belgian physicist diederik aerts has shown great creativity in inventing a number of concrete machine - models that have played an important role in the development of general mathematical and conceptual formalisms for the description of the physical reality .
these models can also be used to demystify much of the strangeness in the behavior of quantum entities , by allowing to have a peek at what s going on in structural terms behind the `` quantum scenes , '' during a measurement . in this author s view
, the importance of these machine - models , and of the approaches they have originated , have been so far seriously underappreciated by the physics community , despite their success in clarifying many challenges of quantum physics . to fill this gap , and encourage a greater number of researchers to take cognizance of the important work of so - called _ geneva - brussels school _
, we describe and analyze in this paper two of aerts historical machine - models , whose operations are based on simple breakable elastic bands . the first one , called the _
spin quantum - machine _
, is able to replicate the quantum probabilities associated with the spin measurement of a spin-@xmath0 entity .
the second one , called the _ connected vessels of water model _ ( of which we shall present here an alternative version based on elastics ) is able to violate bell s inequality , as coincidence measurements on entangled states can do . .
And you have already written the first three sentences of the full article: as is well known , albert einstein was convinced that god does nt play dice with the universe . to that , niels bohr used to reply to stop telling god what s / he has to do with her / his dice .
g. cramer , in more recent times , added to this the following @xcite : `` if ` god plays dice , ' as einstein ( 1932 ) has declined to believe , one would at least like a glimpse of the gaming apparatus that is in use . '' having a glimpse of the apparatus means to _ understand _ the nature of the game that is played behind the quantum scenes , and this in turn means _ to understand quantum mechanics _ , something which most physicists believe is a hopeless goal , in accordance with richard feynman celebrated admonition @xcite : `` [ ... ] that nobody understands quantum mechanics . '' but what does it mean to understand quantum mechanics ? and , more generally , what does it mean to understand something in science ?
different ( more or less sophisticated ) answers are of course possible , depending on the perspective which is adopted . but the majority of scientists will certainly agree that , roughly speaking , to understand in science means to build a theory with a sufficient explanatory power , which can suitably elucidate the observed phenomena and make confirmable predictions ..
Please generate the next two sentences of the article | then , why quantum mechanics , which today has reached the level of a fully mathematized theory , and whose predictions have been confirmed experimentally to an extremely high degree of accuracy , is still considered a theory that nobody really understand , as feynman used to proclaim ?
again , the answer to this question will vary depending on the physicist that respond , but the majority will certainly say that although quantum theory describes and predicts with accuracy the behavior of quantum entities , the problem is that their behavior has nothing to do with that of classical macroscopic entities of our everyday experience . |
9,037 | Suppose that you have an abstract for a scientific paper: di - jet production is studied in collisions of quasi - real photons at centre - of - mass energies from 189 to 209 gev at lep .
the data were collected with the opal detector .
the structure of jets is investigated and differential cross sections are measured and compared to qcd calculations . .
And you have already written the first three sentences of the full article: , for the two regions of --space indicated in the figure ( a ) , and @xmath0 for @xmath1 compared to the predictions of the lo mc generators phojet and pythia ( b ) .
figures ( c ) and ( d ) show the value of @xmath2 as a function of the transverse energy and pseudo - rapidity of the jet respectively , compared to the pythia prediction .
, scaledwidth=47.0% ] at @xmath3 as a function of the jet transverse energy for @xmath4 ( a ) and @xmath5 ( b ) , and as a function of the jet pseudo - rapidity for @xmath4 ( c ) and @xmath5 ( d ) . in each figure.
Please generate the next two sentences of the article | the results obtained using the inclusive and the cone jet algorithm are shown and compared to the pythia prediction.,scaledwidth=47.0% ] we have studied the production of di - jets in the collisions of two quasi - real photons at an centre - of - mass energy from 189 to 209 gev , with a total integrated luminosity of collected by the opal detector at lep .
di - jet events are of particular interest , as the two jets can be used to estimate the fraction of the photon momentum participating in the hard interaction , which is a sensitive probe of the structure of the photon . |
9,038 | Suppose that you have an abstract for a scientific paper: the non - linear response of infinite periodic solids to homogenous electric fields and collective atomic displacements is discussed in the framework of density functional perturbation theory .
the approach is based on the @xmath0 theorem applied to an electric - field - dependent energy functional .
we report the expressions for the calculation of the non - linear optical susceptibilities , raman scattering efficiencies and electrooptic coefficients .
different formulations of third - order energy derivatives are examined and their convergence with respect to the * k*-point sampling is discussed .
we apply our method to a few simple cases and compare our results to those obtained with distinct techniques .
finally , we discuss the effect of a scissors correction on the eo coefficients and non - linear optical susceptibilities . .
And you have already written the first three sentences of the full article: nowadays , density functional theory @xcite ( dft ) is considered as a standard method in condensed matter physics , to study electronic , structural and macroscopic properties of solids from first principles .
combined with adiabatic perturbation theory , it allows _ a priori _ the computation of derivatives of the energy and related thermodynamic potentials up to any order . at the second order ,
this approach has been applied to compute linear response functions such as phonon frequencies or born effective charges with an accuracy of a few percents ..
Please generate the next two sentences of the article | the third - order derivatives are related to non - linear properties such as phonon lifetimes , raman tensors or non - linear optical susceptibilities .
the linear - response formalism has been implemented in various first - principles codes and is routinely applied to an increasing number of systems [ see for example ref . [ ] and references therein ] . |
9,039 | Suppose that you have an abstract for a scientific paper: we expect that s - channel unitarity should materialize in hard dis reactions through screening corrections ( sc ) indicating that the gluon distribution function is approaching saturation , it is not as yet clear what the kinematical scales are at which these effects become important .
while the global dis @xmath0 total cross section , or @xmath1 , data are well reproduced by dglap evolution without substantial sc , there exists experimental data from hera which suggests deviations from dglap predictions in the small @xmath2 and @xmath3 limits .
these signatures are observed in both the fine details of @xmath1 provided @xmath2 and @xmath3 are small enough , as well as in the diffractive channels . in this investigation
we present a detailed study of @xmath4 which is supported by a coupled analysis of @xmath5 photo and dis production .
both channels are directly proportional to @xmath6 , and as such serve as excellent discriminators between different approaches and models . in the first phase of our investigation we have found that none of the latest editions of the parton distribution functions ( grv98 , mrs99 , cteq5 ) provides an adequate and simultaneous reproduction of @xmath2 logarithmic slope of @xmath7 at small @xmath2 values as well as @xmath5 photoproduction
( details of this will be published separately @xcite ) .
we then show that taking grv98nlo as input and correcting it for sc , we can reproduce the recent hera data well .
the calculation depends on one parameter @xmath8 which is directly determined from the @xmath5 photoproduction forward differential slope . with this input
we obtain an excellent fit to the @xmath5 photo and dis production data .
our calculations made in the lla of pqcd take into account the corrections implied by the real part of the production amplitude , off diagonal ( skewed ) gluon distributions and the fermi motion of the charm quarks within the bound charmonium system .
the sc are consistently calculated for both the percolation of a @xmath9....
And you have already written the first three sentences of the full article: over the past few years we have been witness to vigorous experimental , phenomenological and theoretical investigations of the proton deep inelastic scattering ( dis ) structure functions and some exclusive channels with small @xmath10 and @xmath11 .
these comprehensive studies aim at establishing the applicability and possible need for a re - formulation of pqcd , as we know it , when approaching the kinematic interface with the less understood npqcd dominated domain .
the standard procedure for the pqcd analysis of dis on a nucleon target has been to utilize the dglap evolution equations for the structure functions as the key ingredient for fixing the parton distribution functions ( p.d.f . ) ..
Please generate the next two sentences of the article | these p.d.f .
are then used as input for the calculations of exclusive dis channels , usually executed in the color dipole approximation . |
9,040 | Suppose that you have an abstract for a scientific paper: we present _ swift _ broadband observations of the recently discovered black hole candidate , x - ray transient , xtej1752 - 223 , obtained over the period of outburst from october 2009 to june 2010 . from _
swift_-uvot data we confirm the presence of an optical counterpart which displays variability correlated , in the soft state , to the x - ray emission observed by _ swift_-xrt .
the optical counterpart also displays hysteretical behaviour between the states not normally observed in the optical bands , suggesting a possible contribution from a synchrotron emitting jet to the optical emission in the rising hard state .
we offer a purely phenomenological treatment of the spectra as an indication of the canonical spectral state of the source during different periods of the outburst .
we find that the high energy hardness - intensity diagrams over two separate bands follows the canonical behavior , confirming the spectral states .
our xrt timing analysis shows that in the hard state there is significant variability below 10hz which is more pronounced at low energies , while during the soft state the level of variability is consistent with being minimal .
these properties of xtej1752 - 223 support its candidacy as a black hole in the galactic centre region .
[ firstpage ] x - rays : binaries x - rays : bursts binaries : close stars : individual : xtej1752 - 223 .
And you have already written the first three sentences of the full article: low mass x - ray binaries are for the majority of the time in a state of quiescensce with faint or non - detected x - ray emission , though optical or near - infrared ( nir ) counterparts may be visible due to emission from the donor star , or possibly the jet , hot spot , or outer accretion disk .
they are often only discovered when they enter an active state of outburst when powered by an increased level of accretion onto the central , compact object ( black hole or neutron star ) there is a dramatic increase of the x - ray , optical / nir and radio flux . during these outbursts the systems
have been observed to go through a number of high energy spectral states before returning to a quiescent state , usually on times scales of weeks , months or even longer ..
Please generate the next two sentences of the article | these states are a generally low intensity , power - law dominated , _ hard _ state followed by a usually , higher intensity , _ thermal - dominant _ , _ soft _ state which decreases in flux , via a late hard state , over time .
additionally , the hard states are associated with aperiodic variability of the light curve not present in the soft state ( see @xcite for a fuller description of the various possible states ) . |
9,041 | Suppose that you have an abstract for a scientific paper: we report the first extragalactic detection of the neutral carbon [ ci ] fine structure line at 809 ghz . the line was observed towards m82 simultaneously with the line at 492 ghz , providing a precise measurement of the @xmath0 integrated line ratio of 0.96 ( on a scale ) .
this ratio constrains the [ ci ] emitting gas to have a temperature of at least 50 k and a density of at least @xmath1 .
already at this minimum temperature and density , the beam averaged ci - column density is large , @xmath2 , confirming the high ci / co abundance ratio of @xmath3 estimated earlier from the 492 ghz line alone .
we argue that the [ ci ] emission from m82 most likely arises in clouds of linear size around a few pc with a density of about @xmath4 or slightly higher and temperatures of 50k up to about 100k . .
And you have already written the first three sentences of the full article: the fine structure lines of neutral atomic carbon , ci , at 809.3435 ghz and at 492.1607 ghz ( cooksy et al .
@xcite ; yamamoto & saito @xcite ) provide an important diagnostic tool for the physical and chemical conditions of the dense interstellar medium and contribute significantly to the energy balance of the gas .
after the first detections (: phillips et al ..
Please generate the next two sentences of the article | @xcite ; : jaffe et al .
@xcite ) the rapid advance in receiver sensitivity , driven by the technological progress of superconducting mixers now reaching sensitivities of only a few times the quantum limit even at submillimeter wavelengths , has resulted in the line now being well studied in many galactic sources . |
9,042 | Suppose that you have an abstract for a scientific paper: this work reports theoretical and experimental study of the x - ray absorption near - edge structure ( xanes ) at the mn k - edge in ( ga , mn)as diluted magnetic semiconductors . the spectra have been calculated from the first - principles using flapw including the core - hole effect , a special attention has been paid to consequences of coexistence of mn impurities in substitutional and tetrahedral interstitial positions . we have performed quantitative component analysis of experimental spectra collected on the ( ga , mn)as samples before / after annealing and etching , with the aim to determine the proportion of mn impurity configurations .
comparison of the experimental data with theoretical computations indicates that even after annealing and etching some mn atoms still reside in interstitial sites , although the concentration of interstitial defects has been reduced by annealing . .
And you have already written the first three sentences of the full article: recently , the mn - doped gaas system has received considerable attention in view of its potential use in spintronic technology , as it combines both semiconducting / semimetallic and ferromagnetic properties in one physical system @xcite .
the positions of mn dopants play a decisive role in determining the magnetic properties of ( ga , mn)as
. there are three of them with a comparable energy @xcite ..
Please generate the next two sentences of the article | the substitutional mn atoms , mn@xmath0 , occupying ga sites , act as hole - producing acceptors which contribute to ferromagnetism .
the mn atoms in tetrahedral interstitial positions , surrounded by either as or ga atoms , mn@xmath1 and mn@xmath2 , are electron - producing double donors which hinder ferromagnetic states . |
9,043 | Suppose that you have an abstract for a scientific paper: the uv - initiative _ hubble space telescope _ treasury survey of galactic globular clusters provides a new window into the phenomena that shape the morphological features of the horizontal branch ( hb ) . using this large and homogeneous catalog of uv and blue photometry ,
we demonstrate that the hb exhibits discontinuities that are remarkably consistent in color ( effective temperature ) .
this consistency is apparent even among some of the most massive clusters hosting multiple distinct sub - populations ( such as ngc 2808 , @xmath0 cen , and ngc 6715 ) , demonstrating that these phenomena are primarily driven by atmospheric physics that is independent of the underlying population properties .
however , inconsistencies arise in the metal - rich clusters ngc 6388 and ngc 6441 , where the discontinuity within the blue hb ( bhb ) distribution shifts @xmath11,000 k to 2,000 k hotter .
we demonstrate that this shift is likely due to a large helium enhancement in the bhb stars of these clusters , which in turn affects the surface convection and evolution of such stars .
our survey also increases the number of galactic globular clusters known to host blue - hook stars ( also known as late hot flashers ) from 6 to 23 clusters .
these clusters are biased toward the bright end of the globular cluster luminosity function , confirming that blue - hook stars tend to form in the most massive clusters with significant self - enrichment . .
And you have already written the first three sentences of the full article: although globular clusters represent the best available laboratories for constraining stellar evolution models , we now know they are not simple stellar populations . evidence for complex populations
are manifested in all phases of stellar evolution . on the main sequence ( ms ) and
red giant branch ( rgb ) , high - precision photometry reveals distinct sequences that are most prominent in massive clusters such as @xmath0 cen ( e.g. , anderson 1997 ; bedin et al ..
Please generate the next two sentences of the article | 2004 ; ferraro et al .
2004 ) , ngc 2808 ( e.g. , dantona et al . |
9,044 | Suppose that you have an abstract for a scientific paper: recent developments in solid state physics give a prospect to observe the parity anomaly in ( 2 + 1)d massive dirac systems . here
we show , that the quantum anomalous hall ( qah ) state in orbital magnetic fields originates from the dirac mass term and induces an anomalous four - current related to the parity anomaly .
this differentiates the qah from the quantum hall ( qh ) state for the experimentally relevant case of an effective constant density ( seen by the gate ) .
a direct signature of qah phase in magnetic fields is a long @xmath0 ( @xmath1 ) plateau in cr@xmath2(bi@xmath3sb@xmath4)@xmath5te@xmath6 ( hgmnte quantum wells ) .
furthermore , we predict a new transition between the quantum spin hall ( qsh ) and the qah state in magnetic fields , for constant effective carrier density , without magnetic impurities but driven by effective g - factors and particle - hole asymmetry .
this transition can be related to the stability of edge states in the dirac mass gap of 2d topological insulators ( tis ) , even in high magnetic fields . _
introduction : _ condensed matter analogs of the ( 2 + 1)d and ( 3 + 1)d dirac equation , i.e. topological insulators ( ti ) and weyl semimetals , opened new directions to study high energy anomalies in the solid state lab .
an anomaly in high energy physics is defined as breaking of a classical symmetry during regularization @xcite and , in particular , the parity anomaly is characterized by a broken parity symmetry in a quantized theory .
for instance in case of the massless dirac equation in ( 2 + 1)d , coupled to an electromagnetic field , parity symmetry is violated if one insists on gauge - invariance @xcite . in solid state physics on the other hand , `` parity anomaly '' is often understood as generation of an anomalous four - current related to a finite mass term in the dirac equation @xcite . anytime when we relate to the notion of `` parity anomaly '' , we refer to the second definition . at first glance ,
chiral currents related to the....
And you have already written the first three sentences of the full article: in the main text , we discussed how the `` parity anomaly '' gives rise to a change in landau level counting in magnetic field and discussed how this fact is related to signatures in the magnetotransport .
for this purpose , we compare the continuity equation , derived from the semiclassical equations of motion , with the continuity equation , derived from maxwell equations , and show that the qah level has a non - zero chern number but an effective zero charge carrier density .
therefore , in the process of adiabatically switching on magnetic field , the qah state can be distinguished from a trivial insulator when the chemical potential is in the mass gap ..
Please generate the next two sentences of the article | the structure of this appendix is the following : in the first part , we give an explicit derivation of the `` parity anomaly '' based on a semi - classical formulation , while in the second part we show how an additional topological term enters the maxwell equations .
breaking of parity symmetry due to the dirac mass term is discussed in appendix b. let us start from the spin - up block of the bhz hamiltonian @xcite , @xmath143 with @xmath144 , where we have neglected the @xmath145-dependence of the mass term . |
9,045 | Suppose that you have an abstract for a scientific paper: recent theoretical works have demonstrated the realization of fractional quantum anomalous hall states ( also called fractional chern insulators ) in topological flat band lattice models without an external magnetic field .
such newly proposed lattice systems play a vital role to obtain a large class of fractional topological phases . here
we report the exact numerical studies of edge excitations for such systems in a disk geometry loaded with hard - core bosons , which will serve as a more viable experimental probe for such topologically ordered states .
we find convincing numerical evidence of a series of edge excitations characterized by the chiral luttinger liquid theory for the bosonic fractional chern insulators in both the honeycomb disk haldane model and the kagom - lattice disk model .
we further verify these current - carrying chiral edge states by inserting a central flux to test their compressibility . _
introduction. _ one of the most essential and fascinating topics in condensed matter physics is to explore and classify the various states of matter , among which the integer quantum hall effect ( iqhe ) @xcite and the fractional quantum hall effect ( fqhe ) @xcite have long been the major focus .
it is well known that , at fractional fillings , the fqhe will emerge when interacting particles move in landau levels ( lls ) caused by an external uniform magnetic field . on the other hand , great interest has been aroused to realize both the iqhe and fqhe in lattice models in the absence of an external magnetic field .
an initial theoretical attempt was made by haldane @xcite , who proposed a prototype lattice model to achieve the iqhe by introducing two non - trivial topological bands with chern numbers @xmath0 @xcite .
haldane s model demonstrates that the iqhe can also be attained without lls , i.e. defines the quantum anomalous hall ( qah ) states .
the lattice version of the fqhe without lls , however , comes much latter because of its intriguing strongly correlated nature....
And you have already written the first three sentences of the full article: in the main text of this paper , we have obtained edge - state spectra for finite - size disk systems with different boson numbers , whose ground states locate at various angular momenta .
also the periodicity of the energy spectra under flux insertion depends on particle numbers , which is @xmath83 when boson numbers satisfy @xmath80 with @xmath81 and @xmath82 as coprime integers .
we can indeed heuristically understand these numerical results in view of the generalized pauli principle which rules the boson occupancy in single - particle orbitals with particular angular momenta , and considering that many - body states are built from single - particle orbitals with particular flux periodicity.
Please generate the next two sentences of the article | . sites and the trap potential @xmath85 .
( a ) single - particle energy spectrum . |
9,046 | Suppose that you have an abstract for a scientific paper: we describe spinn ( straightforward pulsar identification using neural networks ) , a high - performance machine learning solution developed to process increasingly large data outputs from pulsar surveys .
spinn has been cross - validated on candidates from the southern high time resolution universe ( htru ) survey and shown to identify every known pulsar found in the survey data while maintaining a false positive rate of 0.64% .
furthermore , it ranks 99% of pulsars among the top 0.11% of candidates , and 95% among the top 0.01% . in conjunction with the peasoup pipeline @xcite
, it has already discovered four new pulsars in a re - processing of the intermediate galactic latitude area of htru , three of which have spin periods shorter than 5 milliseconds .
spinn s ability to reduce the amount of candidates to visually inspect by up to four orders of magnitude makes it a very promising tool for future large - scale pulsar surveys . in an effort to provide a common testing ground for pulsar candidate selection tools and
stimulate interest in their development , we also make publicly available the set of candidates on which spinn was cross - validated . .
And you have already written the first three sentences of the full article: discovering pulsars typically involves identifying periodic signals in observational data , then reducing each of them into a set of diagnostic values and graphical representations referred to as a _ candidate_. a modern all - sky pulsar survey such as the high time resolution universe ( htru ; * ? ? ?
* ) produces several million such candidates , the overwhelming majority of which are either the result of human - made radio - frequency interference ( rfi ) , or due to various forms of noise .
the selection of promising candidates to be observed again for confirmation remains up to this day heavily dependent on human inspection , a very time - consuming process becoming increasingly unmanageable as surveys continue to evolve into ever larger scale operations over time ..
Please generate the next two sentences of the article | next generation instruments such as the square kilometre array ( ska ) , can be expected to find 20,000 pulsars @xcite , but not before an estimated 200 million candidates are properly classified , if we are to conservatively assume that the fraction of pulsars to be found among them ( one in ten thousand at most ) is comparable to current surveys @xcite .
this implies that , among other challenges , the problem of automated candidate selection must be decisively solved |
9,047 | Suppose that you have an abstract for a scientific paper: in this work , the solvation and electronic structure of the aqueous chloride ion solution was investigated using density functional theory ( dft ) based _ ab initio _ molecular dynamics ( aimd ) . from an analysis of radial distribution functions , coordination numbers , and solvation structures , we found that exact exchange ( @xmath0 ) and non - local van der waals ( vdw ) interactions effectively _ weaken _ the interactions between the cl@xmath1 ion and the first solvation shell . with a cl - o coordination number in excellent agreement with experiment
, we found that most configurations generated with vdw - inclusive hybrid dft exhibit 6-fold coordinated distorted trigonal prism structures , which is indicative of a significantly disordered first solvation shell . by performing a series of band structure calculations on configurations generated from aimd simulations with varying dft potentials , we found that the solvated ion orbital energy levels ( unlike the band structure of liquid water ) strongly depend on the underlying molecular structures .
in addition , these orbital energy levels were also significantly affected by the dft functional employed for the electronic structure ; as the fraction of @xmath0 was increased , the gap between the highest occupied molecular orbital of cl@xmath1 and the valence band maximum of liquid water steadily increased towards the experimental value . .
And you have already written the first three sentences of the full article: the nature of the interaction between the hydrogen bond ( hb ) network of liquid water and the solvated chloride ion ( a member of the hofmeister series ) is currently a topic under intense research due to its fundamental importance in biochemistry , atmospheric chemistry , and geological processes @xcite .
experimentally , the interaction between the solvated chloride ion , cl@xmath1 , and the surrounding aqueous environment has been successfully probed by a variety of techniques @xcite . in particular , x - ray and neutron scattering as well as x - ray absorption measurements ,
have been used to investigate the solvation structure of aqueous chloride solutions , providing experimental determination of the cl - o and cl - h radial distribution functions ( rdf ) , @xmath2 and @xmath3 , and the associated coordination number , _.
Please generate the next two sentences of the article | i.e. _ , the number of water molecules populating the first solvation shell surrounding a given cl@xmath1 ion @xcite .
in addition , the electronic structure associated with this fundamental aqueous ionic solution was studied by delahay @xcite and winter _ et al . _ |
9,048 | Suppose that you have an abstract for a scientific paper: dipolaritons are a three - way superposition of photon , a direct exciton , and an indirect exciton that are formed in coupled quantum well microcavities . as is the case with exciton - polaritons ,
dipolaritons have a self - interaction due to direct and exchange effects of the underlying electrons and holes . here
we present a theoretical description of dipolaritons and derive simple formulas for their basic parameters .
in particular , we derive the effective dipolariton - dipolariton interaction taking into account of exchange effects between the excitons .
we obtain a simple relation to describe the effective interaction at low densities .
we find that dipolaritons should condense under suitable conditions , described by a dissipative gross - pitaevskii equation .
while the parameters for condensation are promising , we find that the level of tunability of the interactions is limited . .
And you have already written the first three sentences of the full article: the observation of the condensation of exciton - polaritons @xcite has created a large amount of interest in the last decade @xcite .
exciton - polariton condensates display fascinating properties such as superfluidity @xcite , vortex formation @xcite , and has been suggested for use in future technologies such as polaritronics , the polariton analogue of atomtronics @xcite , quantum simulators @xcite , and novel light sources @xcite .
one recent development is the observation of dipolaritons .
Please generate the next two sentences of the article | bosonic quasiparticles formed in coupled double quantum wells embedded into a microcavity formed by two distributed bragg reflectors ( fig .
1 ) @xcite . compared to the exciton - polariton , which is a quasiparticle consisting of a superposition of a photon and an exciton , |
9,049 | Suppose that you have an abstract for a scientific paper: based on the first - principles electronic structure calculations , we predict that a chromium oxide k@xmath0cr@xmath1o@xmath2 of hollandite type should be a half - metallic ferromagnet where the fermi level crosses only the majority - spin band , whereas the minority - spin band has a semiconducting gap .
we show that the double - exchange mechanism is responsible for the observed saturated ferromagnetism .
we discuss possible scenarios of the metal - insulator transition observed at low temperature and we argue that the formation of the incommensurate , long - wavelength density wave of spinless fermions caused by the fermi - surface nesting may be the origin of the opening of the charge gap . .
And you have already written the first three sentences of the full article: half - metallic ferromagnets @xcite offer a unique opportunity for studying the electronic states of strongly correlated electron systems . here , only the majority - spin electrons form the fermi surface with a gapped minority - spin band @xcite and can couple with excitations of the spin ( and in some cases orbital ) degrees of freedom of the system .
the situation therefore should attract much interest , in particular , when the relevant electrons are strongly correlated , leading the system to double - exchange ferromagnetism @xcite and metal - insulator transition ( mit ) . in this paper
, we will show that a chromium oxide k@xmath0cr@xmath1o@xmath2 with the hollandite - type crystal structure @xcite belongs to this class of materials and can provide a good opportunity for further development of the physics of strong electron correlations . the crystal structure of k@xmath0cr@xmath1o@xmath2 ( see fig ..
Please generate the next two sentences of the article | 1 ) belongs to a group of hollandite - type phases where one - dimensional ( 1d ) double strings of edge - shared cro@xmath3 octahedra forms a cr@xmath4o@xmath2 framework of a tunnel structure , wherein k ions reside.@xcite cr ions are in the mixed - valent state of cr@xmath5 ( @xmath6 ) : cr@xmath7 ( @xmath8 ) @xmath9 , and hence with 2.25 electrons per cr ion .
it has recently been reported @xcite that the phase transition from the pauli - paramagnetic metal to ferromagnetic metal occurs at @xmath10 k by lowering temperatures , where the ferromagnetic state has a full spin - polarization of 18 @xmath11 per formula unit ( f.u . ) at low temperatures , which is a realization of saturated ferromagnetism . |
9,050 | Suppose that you have an abstract for a scientific paper: the central dominant galaxies in galaxy clusters constitute the most massive and luminous galaxies in the universe . despite this ,
the formation of these brightest cluster galaxies ( bcgs ) and the impact of this on the surrounding cluster environment remain poorly understood . here
we present multi - wavelength observations of the nearby poor x - ray cluster mz10451 , in which both processes can be studied in unprecedented detail .
_ chandra _ observations of the intracluster medium ( icm ) in the cluster core , which harbors two optically bright early - type galaxies in the process of merging , show that the system has retained a cool core and a central metal excess .
this suggests that any merger induced icm heating and mixing remain modest at this stage .
tidally stripped stars seen around either galaxy likely represent an emerging intracluster light component , and the central icm abundance enhancement may have a prominent contribution from _ in situ _ enrichment provided by these stars .
the smaller of the merging galaxies shows evidence for having retained a hot gas halo , along with tentative evidence for some obscured star formation , suggesting that not all bcg major mergers at low redshift are completely dissipationless .
both galaxies are slightly offset from the peak of the icm emission , with all three lying on an axis that roughly coincides with the large - scale elongation of the icm .
our data are consistent with a picture in which central bcgs are built up by mergers close to the cluster core , by galaxies infalling on radial orbits aligned with the cosmological filaments feeding the cluster . .
And you have already written the first three sentences of the full article: the most massive galaxies in the universe occur in rich groups and clusters .
these brightest cluster galaxies ( hereafter bcgs ) often reside close to the peak of the diffuse x - ray emission from the intracluster medium ( icm ; @xcite ) , and can have recessional velocities indistinguishable from the cluster mean ( @xcite ; but see also @xcite ) . their major axis is preferentially aligned with that of the host cluster , as defined by the projected distribution of cluster galaxies ( e.g. , @xcite ) or the icm x - ray emission @xcite , an effect which seems independent of cluster richness @xcite . furthermore , there is a clear relationship between the stellar luminosity of central bcgs and the total mass and x - ray luminosity of their host cluster @xcite .
these observations suggest that many bcgs reside near the centers of the cluster gravitational potential , and that the formation of central bcgs is intimately linked to the formation and evolution of the cluster itself , as anticipated in a hierarchical structure formation scenario ..
Please generate the next two sentences of the article | this idea is supported by results of cosmological simulations which indicate that central bcgs are built up through a series of mergers near the cluster core ( e.g , @xcite ) .
such simulations also suggest that these mergers must have been predominantly dissipationless , at least for bcg major mergers occurring at low redshift ( e.g. , @xcite ) . |
9,051 | Suppose that you have an abstract for a scientific paper: the thermodynamic and mechanical properties of graphitic systems are strongly dependent on the shear elastic constant @xmath0 . using state - of - the - art density functional calculations
, we provide the first complete determination of their elastic constants and exfoliation energies .
we show that stacking misorientations lead to a severe lowering of @xmath0 of at least one order of magnitude .
the lower exfoliation energy and the lower @xmath0 ( more bending modes ) suggest that flakes with random stacking should be easier to exfoliate than the ones with perfect or rhombohedral stacking .
we also predict ultralow friction behaviour in turbostratic graphitic systems . .
And you have already written the first three sentences of the full article: graphitic systems are used for a wide variety of industrial applications , ranging from lubricant and refractory materials to neutron moderators in nuclear fission reactors@xcite and plasma shields in the next generation of fusion reactors@xcite .
the recent realization of graphene@xcite ( single graphitic layer ) and the discovery of its unusual electronic properties@xcite have raised the interest on flake graphitic systems as a route to produce graphene samples of high quality and in large scale@xcite . despite the technological and scientific importance of graphitic systems ,
the knowledge of their elastic properties is unexpectedly poor and new insights are needed ..
Please generate the next two sentences of the article | the values of the elastic constants describe the mechanical behaviour@xcite and are decisive in engineering design to avoid material failure . in layered materials
, they are even more important for the thermodynamic properties due to a low - lying branch of acoustic vibrations , the bending modes , predicted by lifshitz@xcite over fifty years ago . here we show that the shear elastic constant @xmath0 affects the mechanism of exfoliation that is relevant for the production of graphene |
9,052 | Suppose that you have an abstract for a scientific paper: we present an algorithm that , on input of a cm - field @xmath0 , an integer @xmath1 , and a prime @xmath2 , constructs a @xmath3-weil number @xmath4 corresponding to an ordinary , simple abelian variety @xmath5 over the field @xmath6 of @xmath3 elements that has an @xmath6-rational point of order @xmath7 and embedding degree @xmath8 with respect to @xmath7 .
we then discuss how cm - methods over @xmath0 can be used to explicitly construct @xmath5 . .
And you have already written the first three sentences of the full article: let @xmath5 be an abelian variety defined over a finite field @xmath6 , and @xmath9 a prime number dividing the order of the group @xmath10 .
then the _ embedding degree _ of @xmath5 with respect to @xmath7 is the degree of the field extension @xmath11 obtained by adjoining a primitive @xmath7-th root of unity @xmath12 to @xmath6 .
the embedding degree is a natural notion in pairing - based cryptography , where @xmath5 is taken to be the jacobian of a curve defined over @xmath6 . in this case , @xmath5 is principally polarized and we have the non - degenerate _ weil pairing _ @xmath13\times a[r ] \longrightarrow \mu_r\ ] ] on the subgroup scheme @xmath14 $ ] of @xmath7-torsion points of @xmath5 with values in the @xmath7-th roots of unity ..
Please generate the next two sentences of the article | if @xmath6 contains @xmath12 , we also have the non - trivial _ tate pairing _
@xmath15({{\mathbf f } } ) \times a({{\mathbf f}})/ra({{\mathbf f } } ) \to \mathbf{f}^*/({{\mathbf f}}^*)^r.\ ] ] the weil and tate pairings can be used to ` embed ' @xmath7-torsion subgroups of @xmath10 into the multiplicative group @xmath16 , and thus the discrete logarithm problem in @xmath17 $ ] can be ` reduced ' to the same problem in @xmath16 @xcite . in pairing - based cryptographic protocols @xcite , |
9,053 | Suppose that you have an abstract for a scientific paper: we report on the results from _ suzaku _ x - ray observations of the radio complex region called kookaburra , which includes two adjacent tev @xmath0-ray sources hess j1418 - 609 and hess j1420 - 607 .
the _ suzaku _
observation revealed x - ray diffuse emission around a middle - aged pulsar psr j1420 - 6048 and a plausible pwn rabbit with elongated sizes of @xmath1 and @xmath2 , respectively .
the peaks of the diffuse x - ray emission are located within the @xmath0-ray excess maps obtained by h.e.s.s . and
the offsets from the @xmath0-ray peaks are @xmath3 for psr j1420 - 6048 and @xmath4 for rabbit .
the x - ray spectra of the two sources were well reproduced by absorbed power - law models with @xmath5 .
the spectral shapes tend to become softer according to the distance from the x - ray peaks . assuming the one zone electron emission model as the first order approximation
, the ambient magnetic field strengths of hess j1420 - 607 and hess j1418 - 609 can be estimated as 3 @xmath6 g , and @xmath7 g , respectively .
the x - ray spectral and spatial properties strongly support that both tev sources are pulsar wind nebulae , in which electrons and positrons accelerated at termination shocks of the pulsar winds are losing their energies via the synchrotron radiation and inverse compton scattering as they are transported outward . .
And you have already written the first three sentences of the full article: gamma - ray emitting pulsar wind nebulae ( pwne ) are excellent test grounds for studying pulsars relativistic winds and particle acceleration that takes place presumably at termination shocks . especially , pwne which accompany the diffuse synchrotron x - ray emission show the important clues to understand the time evolution of the pwne and how the accelerated particles escape from the shocks . while young pwne with characteristic ages of less than 10 kyr are relatively well studied in the past observations with _
chandra _ and _ xmm_-_newton _ @xcite , the sample of middle aged pwne remains small .
the kookaburra region includes a middle aged pwn ( psr j1420 - 6048 ) and a plausible pwn ( rabbit ) , making it a suitable target for the detailed study of the diffuse emission with the _ suzaku _ x - ray observatory ..
Please generate the next two sentences of the article | _ suzaku _ , characterized by the low detector background compared to _
chandra _ and _ xmm - newton _ , is crucial for the analysis of faint and diffuse x - ray emission . |
9,054 | Suppose that you have an abstract for a scientific paper: moduli with flat or run - away classical potentials are generic in theories based on supersymmetry and extra dimensions .
they mix between themselves and with matter fields in kinetic terms and in the nonperturbative superpotentials . as the result
, interesting structure appears in the scalar potential which helps to stabilise and trap moduli and leads to multi - field inflation .
the new and attractive feature of multi - inflationary setup are isocurvature perturbations which can modify in an interesting way the final spectrum of primordial fluctuations resulting from inflation . .
And you have already written the first three sentences of the full article: last year s results reported by wmap3 @xcite,@xcite seem to confirm the inflationary paradigm with the spectral index @xmath0 and agree with the cosmic concordance model strengthening the case for dark energy .
therefore it is an actual chalenge for the theory of fundamental interactions to accommodate any of the two ideas in realistic extensions of the standard model ( bsms ) .
four dimensional supergravities stemming from string theories posses field dependent couplings controlled by vevs of moduli - fields which have flat or featureless classical scalar potential ..
Please generate the next two sentences of the article | these fields interact with gravity - strength couplings and appear to be natural candidates to play the role of the inflaton .
in addition , they mix at the level of kinetic or potential energy with all matter - like fields present in the lagrangian , which makes them a part of the inflationary dynamics even if the designed would - be inflaton is not a modulus but rather a matter field . hence , the issue of generating supersymmetric inflation is intertwined with the issue of moduli stabilisation and it is a multi - field rather than a single field phenomenon , which may lead to important consequences . |
9,055 | Suppose that you have an abstract for a scientific paper: droplet microfluidics has emerged as a powerful platform allowing a large number of individual reactions to be carried out in spatially distinct microcompartments . due to their small size
, however , the spectroscopic characterisation of species encapsulated in such systems remains challenging . in this paper
, we demonstrate the acquisition of infrared spectra from single microdroplets containing aggregation - prone proteins . to this effect
, droplets are generated in a microfluidic flow - focussing device and subsequently deposited in a square array onto a znse prism using a micro stamp .
after drying , the solutes present in the droplets are illuminated locally by an infrared laser through the prism , and their thermal expansion upon absorption of infrared radiation is measured with an atomic force microscopy tip , granting nanoscale resolution . using this approach , we resolve structural differences in the amide bands of the spectra of monomeric and aggregated lysozyme from single microdroplets with picolitre volume . .
And you have already written the first three sentences of the full article: lab on a chip technologies offer a range of unique opportunities for preparation and manipulation of molecular species . in particular
, the compartmentalisation of biomolecules into monodisperse , micrometer - sized droplets allows for quantitative , high - throughput biochemical studies such as directed evolution,@xcite screening for reagents , reaction conditions or cells,@xcite as well as for the fabrication of designer emulsions and microgels.@xcite microdroplets can also allow the study of rare events , such as nucleation , and have thus enabled studies of the nucleation step of a@xmath0 aggregation@xcite as well as insulin amyloid growth.@xcite with the rapid development of microfluidic technologies , the need of ultra - sensitive detection methods becomes ever more pressing .
a large fraction of present - day experiments rely on optical detection,@xcite with alternative strategies including , for instance , electrochemistry,@xcite mass spectrometry@xcite or raman spectroscopy.@xcite also , infrared ( ir ) spectroscopy techniques have been utilised to monitor the contents of microfluidic flows.@xcite here , we demonstrate an approach for performing off - line ir spectroscopy on the contents of single microdroplets with sub - micrometer spatial resolution ..
Please generate the next two sentences of the article | fourier transform infrared spectroscopy ( ftir ) is a key method for studying conformational properties of proteins and in particular for inferring their secondary structure.@xcite exposed to ir radiation , chemical bonds undergo vibrations such as stretching , bending and rotating . in the case of proteins , this leads to a spectrum characterised by a set of absorption features in the amide bands.@xcite thereby , the modes most commonly used to study the structural properties of polypeptides are the amide i , amide ii and amide iii bands .
amide i arises mainly from stretching vibrations and is generally localised within 1690 - 1600 @xmath1 ; the exact band position is determined by the backbone conformation - in other words by the secondary structure of the protein . |
9,056 | Suppose that you have an abstract for a scientific paper: we present a new technique for constructing solutions of quasilinear systems of first - order partial differential equations , in particular inhomogeneous ones .
a generalization of the riemann invariants method to the case of inhomogeneous hyperbolic and elliptic systems is formulated .
the algebraization of these systems enables us to construct certain classes of solutions for which the matrix of derivatives of the unknown functions is expressible in terms of special orthogonal matrices .
these solutions can be interpreted as nonlinear superpositions of @xmath0 waves ( or @xmath0 modes ) in the case of hyperbolic ( or elliptic ) systems , respectively .
theoretical considerations are illustrated by several examples of inhomogeneous hydrodynamic - type equations which allow us to construct solitonlike solutions ( bump and kinks ) and multiwave ( mode ) solutions . .
And you have already written the first three sentences of the full article: many nonlinear phenomena appearing in physics are described by first - order quasilinear systems in both their hyperbolic and elliptic regions .
these systems have been mostly studied in the case of two independent variables . however , until now , no satisfactory complete theory exists for those systems . for example , with the exception of certain particular results , the existence and uniqueness theorem for solutions of initial and boundary value problems is not available in general .
such exceptions include the necessary and sufficient conditions for the temporal existence of smooth solutions of hyperbolic systems admitting conservation laws @xcite ..
Please generate the next two sentences of the article | solutions of hyperbolic quasilinear systems do not exist for an arbitrary period of time , even for smooth conditions .
they usually blow up at the end of a finite time interval . in general , the first derivatives of the solution become unbounded after a finite time @xmath1 , and for a time @xmath2 , smooth solutions no longer exist . |
9,057 | Suppose that you have an abstract for a scientific paper: kpd0005 + 5106 is the hottest known helium - rich white dwarf .
we have identified lines in uv and optical spectra and conclude that it is significantly hotter than previously thought , namely @xmath0 k instead of 120000 k. this is a possible explanation for the observed hard x - ray emission as being of photospheric origin . concerning its evolutionary state , we suggest that kpd0005 + 5106 is not a descendant of a pg1159 star but more probably related to the o(he ) stars and rcrb stars . .
And you have already written the first three sentences of the full article: the hottest helium - rich white dwarfs exhibit lines of ionized helium in their optical spectra and they are classified as do white dwarfs . currently forty dos are known .
the coolest one has @xmath1 k and the hottest one is kpd0005 + 5106 . from an analysis of optical and _ hubble space telescope _
fos spectra @xmath2 k and @xmath3 has been derived ( werner et al . 1994 ) for kpd0005 + 5106 ..
Please generate the next two sentences of the article | the sloan digital sky survey has recently revealed another do with @xmath4 k ( hgelmeyer et al . 2006 ) . in the _ far ultraviolet spectroscopic explorer _ (
fuse ) spectra of the hottest pg1159 stars ( @xmath5 k ) we have recently discovered absorption lines of ( werner et al . |
9,058 | Suppose that you have an abstract for a scientific paper: the non - classical spectral and temporal features of entangled photons offer new possibilities to investigate the interactions of excitons in photosynthetic complexes , and to target the excitation of specific states .
simulations of fluorescence in the bacterial reaction center induced by entangled light demonstrate a degree of selectivity of double - exciton states which is not possible using classical stochastic light with the same power spectrum . .
And you have already written the first three sentences of the full article: apart from their evident importance in experimental tests of the foundations of quantum mechanics , entangled photons promise many applications to quantum information processing @xcite , secure quantum communication @xcite , lithography @xcite or metrology @xcite .
in addition , their non - classical frequency and time correlations could also open up novel spectroscopic applications @xcite .
entanglement - induced two - photon transparency @xcite and the linear scaling of two - photon induced fluorescence with the pump intensity @xcite constitute two basic non - classical effects observed with entangled photon pairs ..
Please generate the next two sentences of the article | this scaling makes it possible to carry out nonlinear optical measurements with much lower light intensity compared to classical light , as we will discuss in section [ lightsources ] .
more generally , entangled photons offer new control parameters for nonlinear spectroscopy @xcite , and can be used to distinguish quantum pathways of matter @xcite . |
9,059 | Suppose that you have an abstract for a scientific paper: by a _ conformal string _ in euclidean space is meant a closed critical curve with non - constant conformal curvatures of the conformal arclength functional .
we prove that ( 1 ) the set of conformal classes of conformal strings is in 1 - 1 correspondence with the rational points of the complex domain @xmath0 and ( 2 ) any conformal class has a model conformal string , called _ symmetrical configuration _ , which is determined by three phenomenological invariants : the order of its symmetry group and its linking numbers with the two conformal circles representing the rotational axes of the symmetry group .
this amounts to the quantization of closed trajectories of the contact dynamical system associated to the conformal arclength functional via griffiths formalism of the calculus of variations .
= 1 .
And you have already written the first three sentences of the full article: the mbius geometry of space curves was mainly developed in the first half of the past century @xcite and later taken up starting from the early 1980 s @xcite .
further developments of the subject as an instance of the conformal geometry of submanifolds can be found in @xcite and the literature therein .
the subject has also received much attention for its many fields of application , including the theory of integrable systems @xcite , the topology and mbius energy of knots @xcite , and the geometric approach to shape analysis and medical imaging @xcite . 0.1 cm let @xmath1 , @xmath2 , be a smooth curve parametrized by arclength @xmath3 ..
Please generate the next two sentences of the article | the _ conformal arclength _
parameter @xmath4 of @xmath5 is defined ( up to a constant ) by @xmath6 where @xmath7 is the standard scalar product on @xmath8 . |
9,060 | Suppose that you have an abstract for a scientific paper: a quadric in @xmath0 cuts a curve of degree 6 on a cubic surface in @xmath0 .
the papers classifies the nonsingular curves cut in this way on non - singular cubic surfaces up to homeomorphism .
two issues new in the study related to the first part of the 16th hilbert problem appear in this classification .
one is the distribution of the components of the curve between the components of the non - connected cubic surface which turns out to depend on the patterns of arrangements ( see theorem 1 ) .
the other is presence of positive genus among the components of the complement and genus - related restrictions ( see theorems 3 and 4 ) .
= 6.15pt [ section ] [ thm]lemma [ thm]proposition [ thm]addendum [ thm]remark [ thm]example .
And you have already written the first three sentences of the full article: let @xmath1 be a real algebraic cubic surface in @xmath0 and let @xmath2 be a real algebraic quadric surface in @xmath0 .
this just means that for some homogeneous polynomials @xmath3 , @xmath4 , and @xmath5 , @xmath6 , surfaces @xmath1 and @xmath2 are given by the following equations @xmath7\in{\bbb
r}p^3\ |\ f(x_0,x_1,x_2,x_3)=0\}\\ { \bbb r}q=\{[x_0:x_1:x_2:x_3]\in{\bbb r}p^3\ |\ g(x_0,x_1,x_2,x_3)=0\}.\end{gathered}\ ] ] let @xmath8 and @xmath9 be the complexifications of surfaces @xmath1 and @xmath2 @xmath10\in{\bbb c}p^3\ |\ f(x_0,x_1,x_2,x_3)=0\}\\ { \bbb c}q=\{[x_0:x_1:x_2:x_3]\in{\bbb c}p^3\ |\ g(x_0,x_1,x_2,x_3)=0\}.\end{gathered}\ ] ] we suppose that @xmath8 and @xmath9 are nonsingular and intersect transversely along a curve @xmath11 ..
Please generate the next two sentences of the article | the intersection @xmath12 is a smooth curve in @xmath13 , its real part @xmath14 is @xmath15 .
consider now the diffeomorphism type of @xmath8 , @xmath9 , @xmath11 . |
9,061 | Suppose that you have an abstract for a scientific paper: we study the tachyon scalar field model in flat frw cosmology with the scale factor behavior @xmath0 .
we consider the spherical collapse model and investigate the effects of the tachyon scalar field on the structure formation in flat frw universe .
we calculate @xmath1 , @xmath2 , @xmath3 , @xmath4 , @xmath5 $ ] and @xmath6 $ ] for the tachyon scalar field model and compare the results with the results of eds model and @xmath7 model .
[ firstpage ] tachyon scalar field ; spherical over - densities . .
And you have already written the first three sentences of the full article: the last cosmological and astrophysical data of large scale structure , the observations of type ia and cosmic microwave background radiation have demonstrated that currently there is an acceleration expansion phase in the universe @xcite . the cosmic expansion can be well described by a negative pressure so - called dark energy ( de ) .
the simplest candidate for de is the cosmological constant .
however , the cosmological constant suffers from the fine - tuning and the cosmic coincidence problems @xcite,@xcite,@xcite . therefore , to avoid these problems , different models for dark energy have been proposed such as quintessence , k - essence , tachyon @xcite , phantom , quintom @xcite , and the quantum gravity models , as well as holographic and new agegraphic models @xcite,@xcite . the tachyon model as a scalar field model arises in particle physics and string theory ..
Please generate the next two sentences of the article | thus , it can be considered as one of the potential candidates to describe the nature of the de . on the other hand ,
the problem of structure formation in the universe is a very important issue in theoretical cosmology . |
9,062 | Suppose that you have an abstract for a scientific paper: we present a new method to extract the beam shape incorporated in the pixelized map of cmb experiments .
this method is based on the interplay of the amplitudes and phases of the signal and instrumental noise . by adding controlled white noise onto the map ,
the phases are perturbed in such a way that the beam shape manifests itself through the mean - squared value of the difference between original and perturbed phases .
this method is useful in extracting preliminary antenna beam shape without time - consuming spherical harmonic computations . .
And you have already written the first three sentences of the full article: the future space mission planck will be able to measure , with unprecedented angular resolution and sensitivity , the cosmic microwave background ( cmb ) anisotropy and polarization at 9 frequencies in the range 30857 ghz . in combination with balloon
borne experiments such as boomerang , maxima-1 , tophat and the recently launched space mission map , these observational data will provide a unique base for investigation of the history and the large scale structure formation of the universe .
the accuracy of the cosmological parameter extraction planned for the planck mission is determined by the corresponding accuracy of the systematic effects ..
Please generate the next two sentences of the article | systematic errors can be one of the most important sources of errors for high multipole range of the @xmath0 power spectrum ( @xcite ) .
it is well known that extraction of the information about cosmological parameters such as baryonic density @xmath1 , cold dark matter density @xmath2 , hubble constant @xmath3 , and so on , needs additional information about the statistical characteristics of the measured cmb anisotropy signal from the sky . |
9,063 | Suppose that you have an abstract for a scientific paper: we analyse small - amplitude oscillations of a weakly viscous electrically conducting liquid drop in a strong uniform dc magnetic field .
an asymptotic solution is obtained showing that the magnetic field does not affect the shape eigenmodes , which remain the spherical harmonics as in the non - magnetic case .
strong magnetic field , however , constrains the liquid flow associated with the oscillations and , thus , reduces the oscillation frequencies by increasing effective inertia of the liquid . in such a field , liquid oscillates in a two - dimensional ( 2d ) way as solid columns aligned with the field .
two types of oscillations are possible : longitudinal and transversal to the field .
such oscillations are weakly damped by a strong magnetic field
the stronger the field , the weaker the damping , except for the axisymmetric transversal and inherently 2d modes .
the former are overdamped because of being incompatible with the incompressibility constraint , whereas the latter are not affected at all because of being naturally invariant along the field .
since the magnetic damping for all other modes decreases inversely with the square of the field strength , viscous damping may become important in a sufficiently strong magnetic field .
the viscous damping is found analytically by a simple energy dissipation approach which is shown for the longitudinal modes to be equivalent to a much more complicated eigenvalue perturbation technique .
this study provides a theoretical basis for the development of new measurement methods of surface tension , viscosity and the electrical conductivity of liquid metals using the oscillating drop technique in a strong superimposed dc magnetic field . .
And you have already written the first three sentences of the full article: shape oscillations of levitated metal droplets can be used to measure the surface tension and viscosity of liquid metals ( @xcite ) .
theoretically , the former determines the frequency , while the latter accounts for the damping rate of oscillations . in the reality , experimental measurements may be affected by several side - effects .
firstly , levitated drops may be significantly aspherical and the oscillations amplitudes not necessarily small , whereas the classical theories describing the oscillation frequencies ( @xcite ) and damping rates ( @xcite ) assume small - amplitude oscillations about an ideally spherical equilibrium shape ..
Please generate the next two sentences of the article | corrections due to the drop asphericity have been calculated by @xcite and @xcite .
@xcite find the same order correction to the damping rate resulting also from ac - magnetic field . |
9,064 | Suppose that you have an abstract for a scientific paper: we present a high precision calculation of chargino and neutralino pair production at @xmath0 colliders . within the minimal supersymmetric standard model , the full one - loop and higher order qed corrections
are included .
special care has been taken in the definition of the lagrangian input parameters .
furthermore , the proper inclusion of qed corrections and the separation of weak and qed corrections are discussed .
we show numerical results for total cross sections , as well as forward - backward and left - right asymmetries for the sps1a scenario as proposed in the spa project .
the complete corrections are about 10% and in some cases even larger , in particular for @xmath1 production with sizeable higgsino components .
these corrections have to be taken into account in a high precision analysis .
hephy - pub 806/05 + hep - ph/0504109 * precise predictions for chargino and neutralino pair production in @xmath0 annihilation * w. ller , h. eberl , w. majerotto [ cols= " < " , ] for all other parameters that are free of renormalization conditions , the or on - shell values can be used .
the difference is of higher order for the current processes .
+ since we use an on - shell renormalization , the appropriate tree - level for the one - loop calculation is given in terms of on - shell parameters .
on the other hand , our original input are the @xmath2 parameters of the sps1a scenario .
we therefore show the corrections relative to the tree - level in the spa convention , i.e. calculated in terms of on - shell masses and @xmath2 values for all couplings . using this tree - level definition , the relative corrections are the same compared with those calculated in other renormalization schemes , up to terms of higher order . for this purpose the used @xmath2 value at @xmath3=1 tev of the fine structure constant is @xmath4 . in the presented numerics , we use for the charge renormalization the @xmath5 scheme for neutralino production and the @xmath6 scheme for chargino....
And you have already written the first three sentences of the full article: we have presented in detail the calculation of @xmath14 radiative corrections to the pair production of charginos and neutralinos within the minimal supersymmetric standard model . we discussed a possible separation of weak and qed corrections .
although only the sum of virtual and real bremsstrahlung corrections have physical meaning , a separation of these two contributions has its advantages .
the qed corrections are treated numerically by integration over the phase space with an additional photon in the final state ..
Please generate the next two sentences of the article | quite often a cancellation between qed and weak corrections occurs leading to a small total correction .
furthermore , we used the structure function formalism to include higher order qed corrections and to split the qed corrections into a universal and a non - universal part . |
9,065 | Suppose that you have an abstract for a scientific paper: we investigate poisson properties of postnikov s map from the space of edge weights of a planar directed network into the grassmannian .
we show that this map is poisson if the space of edge weights is equipped with a representative of a 6-parameter family of universal quadratic poisson brackets and the grasmannian is viewed as a poisson homogeneous space of the general linear group equipped with an appropriately chosen r - matrix poisson - lie structure .
we also prove that poisson brackets on the grassmannian arising in this way are compatible with the natural cluster algebra structure . .
And you have already written the first three sentences of the full article: directed planar graphs with weighted edges have been widely used in the study of totally nonnegative matrices ( @xcite ) .
( reviews of the area can be found in @xcite . ) in particular , a special kind of such graphs is a convenient tool for visualizing in the @xmath0 case lusztig type parametrizations of double bruhat cells @xcite .
each parametrization of this kind is obtained via a factorization of an element of a cell into a product of elementary factors ..
Please generate the next two sentences of the article | the standard poisson - lie structure on reductive lie groups is induced by a very simple poisson bracket on factorization parameters .
recently , postnikov used weighted directed planar graphs to parametrize cells in grassmannians @xcite . |
9,066 | Suppose that you have an abstract for a scientific paper: we combine data from sdss and the _ galex _ and _ spitzer _ observatories to create a sample of galaxies observed homogeneously from the uv to the far - ir .
this sample , consisting of @xmath0460 galaxies observed spectroscopically by sdss provides a multiwavelength ( 0.15 - 24 @xmath1 m ) view of obscured and unobscured star formation in nearby ( @xmath2 ) galaxies with sfrs ranging from 0.01 to 100 m@xmath3 yr@xmath4 .
we calculate a robust dust measure from the infrared to uv ratio ( irx ) and explore the influence of star formation history ( sfh ) on the dust - uv color relation ( i.e. the irx-@xmath5 relation ) .
we find that the uv colors of galaxies are only weakly dependent on their sfh as measured by the 4000 break .
however , we find that the contributions of dust and sfh are distinguishable when colors at widely separated wavelengths ( e.g. 0.23 - 3.6 ) are introduced .
we show this explicitly by recasting the irx-@xmath5 relation as a more general irx - sfh - color relation , which we examine in different projections .
we also determine simple fits to this relation . .
And you have already written the first three sentences of the full article: the color of a galaxy is determined primarily by its star formation history ( sfh ) and the amount of dust attenuation present , with significant additional contributions from metallicity and dust geometry .
an empirical relation between sfh , dust attenuation , and color is therefore a useful constraint on models of galaxy formation , and can aid in the interpretation of high redshift galaxy observations where measurements are difficult .
here we investigate such an empirical relation , using a representative sample of galaxies observed from the ultraviolet to the infrared by _ galex _ , sdss , and _.
Please generate the next two sentences of the article | spitzer_. the long wavelength coverage allows us to construct simple but robust measures of dust attenuation that are relatively free of a dependence on sfh .
similarly , the sdss spectroscopy allows us to measure sfh diagnostics we use a 4000 break measure that are largely free of a dependence on dust attenuation . |
9,067 | Suppose that you have an abstract for a scientific paper: this paper provides a precise sense in which the time @xmath0 map for the euler equations of an ideal fluid in a region in @xmath1 ( or a smooth compact @xmath2-manifold with boundary ) is a poisson map relative to the lie - poisson bracket associated with the group of volume preserving diffeomorphism group .
this is interesting and nontrivial because in eulerian representation , the time @xmath0 maps need not be @xmath3 from the sobolev class @xmath4 to itself ( where @xmath5 ) .
the idea of how this difficulty is overcome is to exploit the fact that one does have smoothness in the lagrangian representation and then carefully perform a lie - poisson reduction procedure . .
And you have already written the first three sentences of the full article: hamiltonian structures play a fundamental role in mathematical physics .
it s enough to recall a few examples : classical mechanics , electrodynamics , quantum mechanics , hydrodynamics and general relativity .
however , when applying the classical methods and technics of symplectic geometry to pdes , one faces significant difficulties , both analytical and conceptual ..
Please generate the next two sentences of the article | part of the problem is that symplectic forms that arise in many applications are weak symplectic forms on infinite dimensional manifolds .
more importantly , often integral curves of pdes are not differentiable in time in the function spaces one would normally use ; in the linear case , this corresponds to the fact that the operators involved are unbounded . |
9,068 | Suppose that you have an abstract for a scientific paper: swarm intelligence is a very powerful technique to be used for optimization purposes . in this paper
we present a new swarm intelligence algorithm , based on the bat algorithm .
the bat algorithm is hybridized with differential evolution strategies . besides showing very promising results of the standard benchmark functions
, this hybridization also significantly improves the original bat algorithm . _ to cite paper as follows : i. jr .
fister , d. fister , x .- s yang . a hybrid bat algorithm .
elektrotehniki vestnik , 2013 , in press . .
And you have already written the first three sentences of the full article: nature has always been an inspiration for researchers . in the past
, many new nature - inspired algorithms have been developed to solve hard problems in optimization . in general , there are two main concepts developed in bio - inspired computation : 1 . evolutionary algorithms , 2 .
swarm intelligence algorithms ..
Please generate the next two sentences of the article | the evolutionary algorithms are optimization techniques @xcite that base on the darwin s principle of survival of the fittest @xcite .
it states that in nature the fittest indivi- + duals have greater chances to survive . |
9,069 | Suppose that you have an abstract for a scientific paper: we study the whitham equations for all the higher order kdv equations .
the whitham equations are neither strictly hyperbolic nor genuinely nonlinear .
we are interested in the solution of the whitham equations when the initial values are given by a step function .
[ multiblock footnote omitted ] .
And you have already written the first three sentences of the full article: it is known that the solution of the kdv equation @xmath0 has a weak limit as @xmath1 while the initial values @xmath2 are fixed .
this weak limit is described by hyperbolic equations .
it satisfies the burgers equation @xmath3 until its solution develops shocks . immediately after shock.
Please generate the next two sentences of the article | , the weak limit is governed by the whitham equations @xcite @xmath4 where the @xmath5 s are given by formulae ( [ lambda ] ) .
equations ( [ kdvw ] ) form a @xmath6 system of hyperbolic equations . |
9,070 | Suppose that you have an abstract for a scientific paper: the evolution of the ground - state nuclear shapes in neutron - rich sr , zr , and mo isotopes , including both even - even and odd-@xmath0 nuclei , is studied within a self - consistent mean - field approximation based on the d1s gogny interaction . neutron separation energies and charge radii
are calculated and compared with available data . a correlation between a shape transition and a discontinuity in those observables
is found microscopically . while in sr and zr isotopes the steep behavior observed in the isotopic dependence of the charge radii is a consequence of a sharp prolate - oblate transition , the smooth behavior found in mo isotopes has its origin in an emergent region of triaxiality . 21.60.jz , 21.10.ft , 27.60.+j .
And you have already written the first three sentences of the full article: the study of the properties of unstable nuclei both theoretically and experimentally is nowadays one of the most active and fruitful research lines in nuclear physics .
nuclear systems with very unusual @xmath1 ratios are proper candidates to get insight into the nuclear interaction and the impact that the associated dynamics might have in low - energy observables like the ground - state deformation and derived quantities like moments of inertia or vibrational excitation energies @xcite .
the understanding of the properties of those nuclei also has important consequences in the understanding of other physical processes like stellar nucleosynthesis of heavy elements ..
Please generate the next two sentences of the article | in particular , the neutron - rich sr , zr , and mo isotopes with mass numbers @xmath2 are of special interest for various reasons .
one of them is the role that these isotopes play in the nucleosynthesis of heavy nuclides in the astrophysical r process . |
9,071 | Suppose that you have an abstract for a scientific paper: modifications of spin - splitting dispersion relations and density of states for electrons in non - symmetric heterostructures under in - plane magnetic field are studied within the envelope function formalism .
spin - orbit interactions , caused by both a slow potential and the heterojunction potentials ( which are described by the boundary conditions ) are taken into account .
the interplay between these contributions and the magnetic field contribution to the spin - splitting term in the hamiltonian is essential when energy amount resulting from the zeeman and spin - orbit coupling are of the same order .
such modifications of the energy spectra allow us to separate the spin - orbit splitting contributions due to a slow potential and due to the heterojunctions .
numerical estimates for selectively - doped heterojunction and quantum well with narrow - gap region of electron localization are performed . .
And you have already written the first three sentences of the full article: spin - orbit splitting of the energy dispersion relations for electrons in nonsymmetric quantum heterostructures has been theoretically considered during the past decades ( see ref . for a review ) . in bulk materials spin - orbit interaction
appears both due to a slow - variable potential ( related to the lattice constant ) @xcite and due to cubic 3 and linear @xcite spin - dependent contributions to the effective hamiltonian . turning to the two - dimensional ( 2d ) case
, we can reduce the cubic contribution to a linear one after the replacement of the squared momentum by the quantized value due to confinement @xcite ..
Please generate the next two sentences of the article | it is still more important the fact that we have to take into account an additional spin - orbit splitting of the energy spectrum due to the interaction with abrupt heterojunction potentials ( see ref . and discussion in refs . ) .
such contribution is of a radically different kind with respect to the listed above because contributions from both sides of a slow confinement potential compensate each other @xcite and , therefore , the spin - splitting of 2d states can not be obtained without a short - range potential contribution . to the best of our knowledge , |
9,072 | Suppose that you have an abstract for a scientific paper: in the framework of inflationary models with non - vacuum initial states for cosmological perturbations , we study non - gaussian signatures on the cosmic microwave background ( cmb ) radiation produced by a broken - scale - invariant model which incorporates a feature at a privileged scale in the primordial power spectrum . .
And you have already written the first three sentences of the full article: the common belief that the cmb is gaussian distributed can be directly traced back to the generic assumption that the quantum fluctuations of the inflaton field are placed in the vacuum state @xcite . relaxing
this assumption might lead to detectable signatures in various astrophysical tests , most interestingly in future cmb and large - scale structure observations . in this note , we study cmb non - gaussian signatures predicted within inflationary models with non - vacuum initial states for cosmological perturbations .
the model incorporates a privileged scale , which implies the existence of a feature in the primordial power spectrum ..
Please generate the next two sentences of the article | the model predicts a vanishing three - point correlation function for the cmb temperature anisotropies @xcite .
we here focus on the first non - vanishing moment , the cmb four - point function at zero lag , namely the kurtosis , and compute its expected value for different locations of the primordial feature in the spectrum , as suggested in the literature to conform to observations of large scale structure @xcite . |
9,073 | Suppose that you have an abstract for a scientific paper: selected results of original numeric simulations of non - linear magnetostatic spin waves and microwave - frequency magnetic chaos in ferrite films are expounded , as third part of the work whose first two parts are recent arxive preprints 1204.0200 and 1204.2423 . especially we consider crucial role of parametric processes in creating the chaos and simultaneously obstacles to its synchronization , and examine some possibilities of good enough synchronization ( to an extent allowing its use for direct secure communication in microwave band ) . .
And you have already written the first three sentences of the full article: this preprint continues preprints 1204.0200 and 1204.2423 and represents some results of numerical simulations of auto - generation magnetic - wave chaos in ferrite films , its synchronization and application to secure communication .
a references like ( 6.x ) means formula ( x ) from section 6 placed in 1204.2423 .
sections 1 - 5 are placed in 1204.0200 ..
Please generate the next two sentences of the article | our main interest below is \(i ) visual investigation of regular and chaotic non - linear magnetostatic spin wave patterns auto - generated through feedback consisting of wire inductors ( antennae ) , amplifier and may be filters ; ( ii ) investigation of those conditions of the auto - generation , and properties of generated patterns , what are mostly responsible for characteristics of resulting chaotic microwave - band electric signals ( voltages and currents ) , in particular , their possibilities to synchronize chaotic patterns in other similar systems ( ferrite film ) and thus to serve for secure transmission of information .
7.1 . chaotic auto - generation in film with linear feedback . |
9,074 | Suppose that you have an abstract for a scientific paper: grs 1758258 is one of the few persistent hard x ray emitters ( @xmath0 kev ) in the galaxy . using the asca satellite ,
we have obtained the first detailed data on grs 1758258 in the 110 kev range , where previous observations were affected by confusion problems caused by the nearby strong source gx51 .
the spectrum is well described by a power law with photon index 1.7 without strong fe emission lines . a prominent soft excess , as observed with rosat when the hard x ray flux was in a lower intensity state ,
was not detected .
however , the presence of a soft spectral component , accounting for at most 5% of the 0.1300 kev flux , can not be excluded .
the accurate measurement of interstellar absorption ( @xmath1 cm @xmath2 ) corresponds to an optical extinction which definitely excludes the presence of a massive companion . .
And you have already written the first three sentences of the full article: the source grs 1758258 was discovered in the hard x ray / soft @xmath3ray energy range with the sigma / granat coded mask telescope ( sunyaev et al .
grs 1758258 is of particular interest since , together with the more famous source 1e 1740.7 2942 , it is the only persistent hard x
ray emitter ( @xmath0 kev ) in the vicinity of the galactic center ( goldwurm et al ..
Please generate the next two sentences of the article | both sources have peculiar radio counterparts with relativistic jets ( mirabel et al . 1992a
; rodriguez , mirabel & mart 1992 ; mirabel 1994 ) and might be related to the 511 kev line observed from the galactic center direction ( bouchet et al . |
9,075 | Suppose that you have an abstract for a scientific paper: psrb1931 + 24 is the first intermittent radio pulsar discovered to date , characterized by a 0.8s pulsation which turns on and off quasi - periodically every @xmath035days , with a duty cycle of @xmath010% .
we present here x ray and optical observations of psrb1931 + 24 performed with the _ chandra x - ray observatory _ and _ isaac newton telescope _ , respectively .
simultaneous monitoring from the _ jodrell bank observatory _ showed that this intermittent pulsar was in the radio on phase during our observations .
we do not find any x ray or optical counterpart to psrb1931 + 24 , translating into an upper limit of @xmath1ergs@xmath2 on the x ray luminosity , and of @xmath3 on the optical magnitude .
if the pulsar is isolated , these limits can not constrain the dim x - ray and optical emission expected for a pulsar of that age ( @xmath01.6myr ) .
we discuss the possibility that the quasi periodic intermittent behavior of psrb1931 + 24 is due to the presence of a low mass companion star or gaseous planet , tight with the pulsar in an eccentric orbit . in order to constrain the parameters of this putative binary system
we re - analysed the pulsar radio timing residuals and we found that ( if indeed hosted in a binary system ) , psrb1931 + 24 should have a very low mass companion and an orbit of low inclination .
[ firstpage ] stars : pulsars : general pulsar : individual : psrb1931 + 24 .
And you have already written the first three sentences of the full article: a long term radio monitoring study of the @xmath4ms radio pulsar psrb1931 + 24 ( stokes et al . 1985 ; hobbs et al .
2004 ) , revealed the peculiar intermittent behavior of this pulsar ( kramer et al .
psrb1931 + 24 is ( so far ) a unique system : it shows an active radio emission phase lasting between 510 days ( radio on phase , hereafter ) , which suddenly ( in less than 10s ) switches off , and the pulsar remains undetectable for the following 2535 days ( radio off phase , hereafter ) ..
Please generate the next two sentences of the article | this pattern repeats quasi - periodically , and has been monitored for the past 7 years ( kramer et al .
another peculiar property of psrb1931 + 24 is its spin down behavior . |
9,076 | Suppose that you have an abstract for a scientific paper: we study possible crossing of the phantom divide line in a dgp - inspired @xmath0 braneworld scenario where scalar field and curvature quintessence are treated in a unified framework . with some specific form of @xmath0 and by adopting a suitable ansatz , we show that there are appropriate regions of the parameters space which account for late - time acceleration and admit crossing of the phantom divide line . *
key words * : braneworld cosmology , dgp scenario , dark energy models , late - time acceleration + * pacs * : 04.50.+h , 98.80.-k 0 mm 0 mm 0 mm 0 mm 0 mm 165 mm .65 cm + and + .
And you have already written the first three sentences of the full article: based on several astronomical evidences , our universe is currently in a period of positively accelerated expansion [ 1 ] .
it is possible to interpret this late - time acceleration based on yet unknown component called dark energy in literature ( see for instance [ 2 ] with a comprehensive list of references therein ) .
also , it has been shown that such an accelerated expansion could be the result of a modification to the einstein - hilbert action ( for a recent review see [ 3 ] ) ..
Please generate the next two sentences of the article | on the other hand , dgp braneworld scenario has the capability to interpret this late - time acceleration via leakage of gravity to extra dimension in its self - accelerating branch [ 4 ] .
for the first alternative , the simplest candidate for dark energy is the cosmological constant itself . |
9,077 | Suppose that you have an abstract for a scientific paper: we consider the @xmath0-body problem in @xmath1 with the newtonian potential @xmath2 .
we prove that for every initial configuration @xmath3 and for every minimizing normalized central configuration @xmath4 , there exists a collision - free parabolic solution starting from @xmath3 and asymptotic to @xmath4 .
this solution is a minimizer in every time interval .
the proof exploits the variational structure of the problem , and it consists in finding a convergent subsequence in a family of minimizing trajectories .
the hardest part is to show that this solution is parabolic and asymptotic to @xmath4 . .
And you have already written the first three sentences of the full article: in this paper we consider @xmath0 positive masses in an euclidean space @xmath1 , submitted to a gravitational interaction .
we find some interesting solutions with a given asymptotic behaviour .
the equation of motion of the @xmath0-body problem is written @xmath5 where @xmath6 is the mass and @xmath7 the position of the @xmath8-th body . since these equations are invariant by translation , we can assume that the center of mass is at the origin ..
Please generate the next two sentences of the article | + these equations are euler - lagrange equations of the lagrangian action functional ( we will define it precisely in the next section ) , therefore solutions of ( [ newt ] ) are critical points of the action in a set of paths with fixed ends .
the simplest kind of critical points are minima , so it is natural to search for minimizers of the lagrangian action joining two given configurations in a fixed time . |
9,078 | Suppose that you have an abstract for a scientific paper: we show that the electromagnetically induced transparency ( eit ) is possible in a medium exhibiting rydberg excitons and indicate the realistic parameters to perform the experiment .
the calculations for a cu@xmath0o crystal are given which show that in this medium due to large group index one could expect slowing down a light pulse by a factor about @xmath1 . .
And you have already written the first three sentences of the full article: recently , a lot of attention has been directed to the subject of excitons in bulk crystals due to experimental observation of the so - called yellow exciton series in cu@xmath0o up to a large principal quantum number of @xmath2 @xcite-@xcite .
such excitons in copper oxide , in analogy to atomic physics , have been named rydberg excitons . by virtue of their special properties
rydberg excitons are of fascination in solid state and optical physics . these objects , whose size scales as the square of the rydberg principal quantum number @xmath3 , are ideally suited for fundamental quantum interrogations , as well as detailed classical analysis ..
Please generate the next two sentences of the article | one could expect that rydberg excitons would have been described , in analogy to rydberg atoms , by rydberg series of hydrogen atoms , but it turned out that this generic method of description should has been revised because diameter of such exciton is much larger then wavelength of light needed to create it @xcite .
the observation and detailed description of rydberg excitons have opened a new field in condensed matter spectroscopy . in analogy to medium of rydberg atoms , where it has been possible to obtain a large optical nonlinearity at the single photon level and to realize a lot of quantum optics sophisticated experiments such as optical kerr effect or correlated states @xcite , it is expected that the medium of rydberg excitons is also fertile area . |
9,079 | Suppose that you have an abstract for a scientific paper: aggregation of dust through sticking collisions is the first step of planet formation .
basic physical properties of the evolving dust aggregates strongly depend on the porosity of the aggregates , e.g. mechanical strength , thermal conductivity , gas - grain coupling time .
also the outcome of further collisions depends on the porosity of the colliding aggregates . in laboratory experiments
we study the growth of large aggregates of @xmath0 3 mm to 3 cm through continuous impacts of small dust agglomerates of 100 @xmath1 m size , consisting of @xmath1 m grains at different impact velocities .
the experiments show that agglomerates grow by direct sticking as well as gravitational reaccretion .
the latter can be regarded as suitable analog to reaccretion of fragments by gas drag in protoplanetary disks .
experiments were carried out in the velocity range between 1.5 m / s and 7 m / s . with
increasing impact velocities the volume filling factor of the resulting agglomerates increases from @xmath2 for 1.5 m / s to @xmath3 for 7 m / s .
these values are independent of the target size .
extrapolation of the measured velocity dependence of the volume filling factor implies that higher collision velocities will not lead to more compact aggregates .
therefore , @xmath3 marks a degree of compaction suitable to describe structures forming at @xmath4 . at small collision velocities below 1 m
/ s highly porous structures with @xmath5 will form . for intermediate collision velocities porosities vary .
depending on the disk model and resulting relative velocities , objects in protoplanetary disks up to dm - size might evolve from highly porous ( @xmath5 ) to compact ( @xmath3 ) with a more complex intermediate size range of varying porosity . .
And you have already written the first three sentences of the full article: coagulation of dust particles by mutual collisions is a fundamental process occuring in protoplanetary disks .
it marks the first steps of planet formation .
the formation of millimeter size aggregates from micron - sized dust particles proceeds rapidly . as collision velocities in this range.
Please generate the next two sentences of the article | are small and particles stick together easily , the growth of aggregates is indisputable @xcite . with increasing particle size , also the relative velocities between particles increase and velocities reach values up to 60 m / s for meter size bodies or even more , eventually @xcite .
with increasing velocities collision results become more complex and compaction , fragmentation and rebound are typical outcomes @xcite . |
9,080 | Suppose that you have an abstract for a scientific paper: the magnetization relaxation rate of small particles dispersed in a silica matrix has been measured from 60 mk to 5 k. it shows a minimum around 150 mk , that can be discussed in terms of either thermal or quantum relaxation regime . .
And you have already written the first three sentences of the full article: the magnetization dynamics of single - domain nanometric particles at low temperature is presently a subject of intense interest , in the hope of finding evidence for quantum tunneling of the magnetic moment through the anisotropy barrier associated with the particle @xcite .
apart from some pioneering attempts at a study of a unique particle @xcite , most efforts are concentrated on macroscopic samples , in which an accurate knowledge of the effective distribution of barriers is difficult , hence hindering a clear interpretation of the results @xcite,@xcite . moreover , except in a few cases @xcite , the low - temperature range of the published data is often limited to pumped - he cryogenic techniques ( @xmath0 ) , which still makes an unambiguous characterization of quantum effects more difficult . in this paper , we present magnetic measurements which have been performed using a dilution refrigerator @xcite , that allow data to be taken down to @xmath1 .
we have studied a sample of particles , dispersed in a silica matrix , with a typical diameter of @xmath2 ..
Please generate the next two sentences of the article | the relaxation dynamics of particles has already been shown to exhibit some anomalies @xcite , that appear at the very end of the accessible temperature range ( 1.8 k ) .
our present data show that the relaxation rates in our sample do indeed fail to go down to zero when the temperature is lowered to @xmath3 . |
9,081 | Suppose that you have an abstract for a scientific paper: the wavelength dependence of atmospheric refraction causes differential chromatic refraction ( dcr ) , whereby objects imaged at different optical / uv wavelengths are observed at slightly different positions in the plane of the detector .
strong spectral features induce changes in the effective wavelengths of broad - band filters that are capable of producing significant positional offsets with respect to standard dcr corrections .
we examine such offsets for broad - emission - line ( type 1 ) quasars from the sloan digital sky survey ( sdss ) spanning @xmath0 and an airmass range of 1.0 to 1.8 .
these offsets are in good agreement with those predicted by convolving a composite quasar spectrum with the sdss bandpasses as a function of redshift and airmass .
this astrometric information can be used to break degeneracies in photometric redshifts of quasars ( or other emission - line sources ) and , for extreme cases , may be suitable for determining `` astrometric redshifts '' . on the sdss s southern equatorial stripe , where it is possible to average many multi - epoch measurements ,
more than 60% of quasars have emission - line - induced astrometric offsets larger than the sdss s relative astrometric errors of 25 - 35 mas .
folding these astrometric offsets into photometric redshift estimates yields an improvement of 9% within @xmath1 .
future multi - epoch synoptic surveys such as lsst and pan - starrs could benefit from intentionally making @xmath2 observations at relatively high airmass ( @xmath3 ) in order to improve their photometric redshifts for quasars . .
And you have already written the first three sentences of the full article: the next generation of large - area survey facilities ( e.g. , pan - starrs , lsst , des , vista / vst ; @xcite ) will image orders of magnitude more objects than it will be possible to obtain spectra for . as a result ,
robust determination of redshifts from photometric data is of crucial importance to these projects . while the distinctive `` 4000@xmath4break '' facilitates photometric redshifts ( `` photo-@xmath5 s '' ) for galaxies ( e.g. , * ? ? ?
* ; * ? ? ?.
Please generate the next two sentences of the article | * ) , the majority of quasars ( @xmath6 ) lack such a strong spectral feature at observed - frame optical wavelengths , making the determination of photometric redshifts for low-@xmath5 quasars more challenging . while it has been proven to be possible to determine photo-@xmath5 s of quasars from the changes that their emission lines induce in their broad - band photometry ( e.g. , * ? ? ?
* ; * ? ? ? |
9,082 | Suppose that you have an abstract for a scientific paper: we consider a two dimensional kondo lattice model with exchange @xmath0 and hopping @xmath1 in which three out of four impurity spins are removed in a regular way . at the particle - hole symmetric
point the model may be studied with auxiliary field quantum monte carlo methods without sign problems . to achieve the relevant energy scales on finite clusters , we introduce a simple method to reduce size effects by up to an order of magnitude in temperature . in this model ,
a metallic phase survives up to arbitrarily low temperatures before being disrupted by magnetic fluctuations which open a gap in the charge sector .
we study the formation of the heavy - electron state with emphasis on a crossover scale @xmath2 defined by the maximum in the resistivity versus temperature curve . the behavior of thermodynamic properties such as specific heat as well as spin and charge uniform susceptibilities are studied as the temperature varies in a wide range across @xmath2
. within our accuracy @xmath3 compares well to the kondo scale of the related single impurity problem .
finally our qmc resuls are compared with mean - field approximations .
+ pacs numbers : 71.27.+a , 71.10.-w , 71.10.fd + + .
And you have already written the first three sentences of the full article: kondo insulators as well as heavy fermion materials @xcite are believed to be described by kondo lattice models with antiferromagnetic exchange @xmath0 and hopping @xmath1 . in this framework
, the kondo insulator - exemplified by ce@xmath4bi@xmath5pt@xmath4 - corresponds to a special band filling in which there is exactly one conduction electron per impurity spin .
the origin of the charge and spin gaps is easy to understand in the limit of large @xmath6 where each conduction electron is trapped by an impurity spin to form a kondo singlet . starting from this point there are two ways of generating metallic states which will described the heavy electron state . on one hand.
Please generate the next two sentences of the article | , one can remove conduction electrons thus leaving uncompensated impurity spins . in the limit
@xmath7 the problem maps onto the @xmath8 hubbard model where the kondo singlets are represented by empty sites and the bachelor - or unscreened - spins by electrons @xcite . |
9,083 | Suppose that you have an abstract for a scientific paper: eclipses in the 14.4 day period double - lined binary ss lac were observed photographically and visually early in the 20@xmath0 century , but stopped some 50 or 60 years ago .
this has been explained by the presence of a distant third star in the system , which has now been detected spectroscopically with a period of 679 days .
the plane of the orbit of the binary is changing relative to the line of sight in response to perturbations from this third object . a recent analysis by milone et al .
of all photometric material available for the system , including a re - measurement of original harvard plates , has confirmed earlier reports of changes in the depth of the eclipses as a function of time , which are due to the third star . in this paper
we discuss our detailed analysis of the eclipse amplitude measurements , and extract from them information on the change in the inclination angle of the binary over the last century .
our use of a much improved ephemeris for the system by torres & stefanik was found to be crucial , and prompted us to re - determine all the amplitudes from the historical data at our disposal , including the harvard material used by m00 .
systematically lower measurements on the branches of the minima were properly accounted for , and we made use of both a linear approximation to the time variation of the inclination angle and a more realistic model based on the theory of three - body interactions ( regression of the nodes " effect ) .
the nodal cycle is found to be @xmath1600 yr , within which _ two _ eclipse seasons " occur , each lasting about 100 yr . the non - eclipsing status of the system is expected to continue until the beginning of the 23@xmath2 century . to appear in _ the astronomical journal _ , april 2001 .
And you have already written the first three sentences of the full article: the cessation of eclipses in a binary star is a rare phenomenon that can most often be explained by the presence of a third object in the system inducing perturbations in the orbital elements of the inner pair .
the modulation of the inclination angle to the line of sight , in particular , is the direct cause of a change in the orientation of the plane of the binary such that eventually the stars no longer block each other s light at conjunction .
few examples of this phenomenon are known , among them ay mus ( sderhjelm 1974 ) and v907 sco ( lacy , helt & vaz 1999 ) ..
Please generate the next two sentences of the article | an especially interesting case is ss lacertae ( hip 108981 , bd@xmath33782 , @xmath4 days , , @xmath5 , @xmath6 , epoch and equinox j2000 ) , which stopped eclipsing around the middle of the 20@xmath0 century .
our knowledge about light variations in this binary when it _ was _ eclipsing comes entirely from visual and photographic measurements that go back more than a century , but that are unfortunately of rather poor quality . |
9,084 | Suppose that you have an abstract for a scientific paper: this paper contains bounds for the distortion in the spherical metric , that is to say bounds for the constant of hlder continuity of mappings @xmath0 where @xmath1 denotes the spherical metric .
the mappings considered are @xmath2-quasiconformal ( @xmath3 ) and satisfy some normalizations or restrictions . all bounds are explicit and asymptotically sharp as @xmath4 . .
And you have already written the first three sentences of the full article: in this paper we derive explicit asymptotically sharp estimates for the constant of hlder continuity in the spherical metric of quasiconformal ( qc ) mappings .
these results are based on reducing the problem to the euclidean metric case , where hlder continuity is well - known .
the paper @xcite provides explicit estimates with some nice properties ( cflemma [ m1fv ] ) that will be shown to hold for the constants in the spherical metric also . a similar , but more restricted ,.
Please generate the next two sentences of the article | result has previously appeared as lemma 4.1 of @xcite ( cited as lemma [ bonlem ] in this paper ) .
this result gives an estimate for the hlder constant with respect to the spherical metric of planar quasiconformal mappings , which , however , is not asymptotically sharp as @xmath5 . |
9,085 | Suppose that you have an abstract for a scientific paper: this paper describes joint work with oded schramm and wendelin werner establishing the values of the planar brownian intersection exponents from which one derives the hausdorff dimension of certain exceptional sets of planar brownian motion .
in particular , we proof a conjecture of mandelbrot that the dimension of the frontier is @xmath0 .
the proof uses a universality principle for conformally invariant measures and a new process , the stochastic loewner evolution ( @xmath1 ) , introduced by schramm .
these ideas can be used to study other planar lattice models from statistical physics at criticality .
i discuss applications to critical percolation on the triangular lattice , loop - erased random walk , and self - avoiding walk .
4.5 mm * 2000 mathematics subject classification : * 60j65 , 60k35 . * keywords and phrases : * brownian motion , critical exponents , conformal invariance , stochastic loewner evolution . .
And you have already written the first three sentences of the full article: -5 mm let @xmath2 be a standard brownian motion taking values in @xmath3 and let @xmath4 $ ] denote the random set @xmath5 = \{b_r : s \leq r \leq t\ } .$ ] for @xmath6 , we say that @xmath2 is a * _ cut point _ for @xmath7 $ ] if @xmath8 = \emptyset $ ] ; * _ frontier point _ for @xmath7 $ ] if @xmath2 is on the boundary of the unbounded component of @xmath9 $ ] ; * _ pioneer point _ for @xmath7 $ ] if @xmath2 is on the boundary of the unbounded component of @xmath10 $ ] , i.e. , if @xmath2 is a frontier point for @xmath11 $ ] .
i will discuss the following result proved by oded schramm , wendelin werner , and myself .
* theorem 1 . *.
Please generate the next two sentences of the article | @xcite _ if @xmath2 is a standard brownian motion in @xmath3 , then with probability one , @xmath12\ ; ] = 3/4 , \ ] ] @xmath13\ ; ] = 4/3 , \ ] ] @xmath14\;]= 7/4 , \ ] ] where @xmath15 denotes hausdorff dimension .
_ mandelbrot @xcite first gave the conjecture for the brownian frontier , basing his conjecture on numerical simulation and then noting that simulations of the frontier resembled simulations of self - avoiding walks . |
9,086 | Suppose that you have an abstract for a scientific paper: si riporta per la prima volta il testo critico completo di un manoscritto di ettore majorana , conservato insieme agli appunti per le lezioni tenute alluniversit di napoli e redatto probabilmente per un seminario svolto in quella universit .
alcuni passaggi del testo rivelano , in forma latente , una interpretazione fisica della meccanica quantistica che anticipa di molti anni lapproccio di feynman in termini di integrali sui cammini , indipendentemente dalla formulazione matematica sottostante ad esso . .
And you have already written the first three sentences of the full article: linteresse per le lezioni del corso di fisica teorica , svolte da ettore majorana alluniversit di napoli nel 1938 , stato recentemente ravvivato dal ritrovamento del documento moreno @xcite , una trascrizione fedele da parte di eugenio moreno degli appunti delle lezioni preparati dallo stesso majorana , comprensiva di alcune lezioni precedentemente ignote e i cui originali sembrano essere andati dispersi .
gli appunti originali sono conservati a pisa , e furono riprodotti anastaticamente alcuni anni or sono @xcite , includendovi anche alcuni fogli che si voluto interpretare @xcite @xcite come gli appunti preliminari per la lezione successiva alla ventunesima , che majorana avrebbe svolto se non fosse scomparso .
sebbene il carattere `` preliminare '' , ossia di appunti di uso personale da non consegnare direttamente agli studenti , sia ampiamente attestato dalle inusuali numerose cancellature che vi sono presenti , unanalisi attenta dei contenuti ivi svolti non sembra indicare che tali appunti siano stati redatti per il corso di fisica teorica n , tantomeno , preparati per la lezione imediatamente successiva alla ventunesima ..
Please generate the next two sentences of the article | infatti , come si pu constatare facilmente , tali appunti svolgono argomenti avanzati e niente affatto collegati a quanto trattato da majorana nelle sue ultime tre lezioni , in cui egli aveva appena introdotto le basi della meccanica ondulatoria e della sua interpretazione statistica .
qui si presuppongono , invece , conoscenze che il docente non aveva certamente ancora fornito nel suo corso e si sviluppano delle |
9,087 | Suppose that you have an abstract for a scientific paper: the atlasgal 870@xmath0 m continuum survey conducted with the apex telescope is the first survey covering the whole inner galactic plane ( @xmath1 & @xmath2 ) in submm continuum emission tracing the cold dust of dense and young star - forming regions . here , we present the overall distribution of sources within our galactic disk .
the submm continuum emission is confined to a narrow range around the galactic plane , but shifted on average by @xmath30.07deg below the plane .
source number counts show strong enhancements toward the galactic center , the spiral arms and toward prominent star - forming regions . comparing the distribution of atlasgal dust continuum emission to that of young intermediate- to high - mass young stellar objects ( ysos ) derived from spitzer data ,
we find similarities as well as differences . in particular
, the distribution of submm dust continuum emission is significantly more confined to the plane than the yso distribution ( fwhm of 0.7 and 1.1deg , corresponding to mean physical scale heights of approximately 46 and 80pc , respectively ) . while this difference may partly be caused by the large extinction from the dense submm cores , gradual dispersal of stellar distributions after their birth
could also contribute to this effect .
compared to other tracers of galactic structure , the atlasgal data are strongly confined to a narrow latitude strip around the galactic plane . .
And you have already written the first three sentences of the full article: since the location of our solar system is within the galactic disk , studying the galactic structure of our milky way is always a challenging problem .
therefore , we can not derive such comprehensive and intuitive pictures of our disk as extragalactic studies are able to do for other spiral galaxies ( e.g. , @xcite ) . nevertheless , based on a diverse set of studies over all wavelengths , in the last few decades we have derived a reasonably comprehensive picture of our galactic spiral structure ( for recent work ,
see , e.g. , @xcite ) ..
Please generate the next two sentences of the article | the galactic plane has been observed in the optical / near-/mid - infrared bands ( e.g. , @xcite ) as well as at longer wavelengths , e.g. , in co or cm continuum emission ( e.g. , @xcite ) .
however , until the arrival of the two ( sub)mm galactic plane surveys atlasgal ( the apex telescope large area survey of the galaxy at 870@xmath0 m ) and bgps ( bolocam galactic plane survey ) @xcite , no survey at ( sub)mm wavelengths existed that trace the cold dust emission stemming from dense and young star - forming regions at adequate spatial resolution ( the cobe ( cosmic background explorer ) and wmap ( wilkinson microwave anisotropy probe ) data have too coarse resolution to isolate individual star - forming regions ) . here , we employ the 870@xmath0 m submm continuum survey atlasgal to study the general distribution of the dense dust and gas within our galactic plane . |
9,088 | Suppose that you have an abstract for a scientific paper: in a recent study @xcite the stationary state of a parallel - update tasep with varying system length , which can be regarded as a queueing process with excluded - volume effect ( _ exclusive queueing process _ , eqp ) , was obtained .
we analyze the dynamical properties of the number of particles @xmath0 and the position of the last particle ( the system length ) @xmath1 , using an analytical method ( generating function technique ) as well as a phenomenological description based on domain wall dynamics and monte carlo simulations .
the system exhibits two phases corresponding to linear convergence or divergence of @xmath2 and @xmath3 .
these phases can both further be subdivided into high - density and maximal - current subphases .
the predictions of the domain wall theory are found to be in very good agreement quantitively with results from monte carlo simulations in the convergent phase . on the other hand , in the divergent phase
, only the prediction for @xmath0 agrees with simulations . .
And you have already written the first three sentences of the full article: queueing processes have been studied extensively , especially due to their practical relevance @xcite .
however , usually the spatial structure of the queues is neglected and the particles in the queues do not interact with each other . on the other hand , the totally asymmetric simple exclusion process ( tasep ) which has a spatial structure and excluded - volume effect ( hard - core repulsion ) is one of the best - studied interacting particle systems @xcite . nowadays
the tasep is a basic model for pedestrian and traffic flows @xcite ..
Please generate the next two sentences of the article | recently a queueing process with the excluded - volume effect , the exclusive queueuing process ( eqp ) , was introduced in @xcite and @xcite independently , where the model was formulated as continuous - time and discrete - time markov processes , respectively .
this model can be rephrased as the tasep on a semi - infinite chain with a new boundary condition , see fig . |
9,089 | Suppose that you have an abstract for a scientific paper: a generalized version of the tknn - equations computing hall conductances for generalized dirac - like harper operators is derived .
geometrically these equations relate chern numbers of suitable ( dual ) bundles naturally associated to spectral projections of the operators .
address = dpartement de mathmatiques , universit de cergy - pontoise , 95302 cergy - pontoise , france , [email protected] address = dipartimento di matematica , universit di trieste , i-34127 trieste , italy + and infn , sezione di trieste italy , [email protected] .
And you have already written the first three sentences of the full article: the _ integer quantum hall effect _ ( iqhe ) reveals a variety of surprising and attractive physical features , and has been the subject of several investigations ( see @xcite and references therein ) .
in fact , a complete spectral analysis of the schrdinger operator for a single particle moving in a plane in a periodic potential and subject to an uniform orthogonal magnetic field of strength @xmath0 ( _ magnetic bloch electron _ ) is extremely difficult .
thus the need for simpler effective models which hopefully capture ( some of ) the main physical features in suitable physical regimes . in the limit of a strong magnetic field ,.
Please generate the next two sentences of the article | @xmath1 , the iqhe is well described by an effective harper operator ( cf .
@xcite ) . for this model |
9,090 | Suppose that you have an abstract for a scientific paper: we propose a single - site addressing implementation based on the sub - wavelength localization via adiabatic passage ( slap ) technique .
we consider a sample of ultracold neutral atoms loaded into a two - dimensional optical lattice with one atom per site .
each atom is modeled by a three - level @xmath0 system in interaction with a pump and a stokes laser pulse . using a pump field with a node in its spatial profile ,
the atoms at all sites are transferred from one ground state of the system to the other via stimulated raman adiabatic passage , except the one at the position of the node that remains in the initial ground state .
this technique allows for the preparation , manipulation , and detection of atoms with a spatial resolution better than the diffraction limit , which either relaxes the requirements on the optical setup used or extends the achievable spatial resolution to lattice spacings smaller than accessible to date . in comparison to techniques based on coherent population trapping
, slap gives a higher addressing resolution and has additional advantages such as robustness against parameter variations , coherence of the transfer process , and the absence of photon induced recoil .
additionally , the advantages of our proposal with respect to adiabatic spin - flip techniques are highlighted .
analytic expressions for the achievable addressing resolution and efficiency are derived and compared to numerical simulations for @xmath1rb atoms in state - of - the - art optical lattices . .
And you have already written the first three sentences of the full article: ultracold neutral atoms in an optical lattice with single - atom and single - site resolution constitute an ideal physical system to investigate strongly correlated quantum phases @xcite which , in turn , has interesting applications in quantum optics @xcite , quantum simulation @xcite and quantum information processing @xcite , among others . the first approaches towards single - site addressing considered the use of lattices with relatively large site separations @xcite
. however , to have access to the regime of strongly correlated systems , typical lattice spacings well below @xmath2 m are needed since the tunneling rate has to be comparable to the on site interactions . in this case , the diffraction limit imposes strong restrictions on the addressability of individual lattice sites . to overcome this
limitation different techniques have been investigated ..
Please generate the next two sentences of the article | for instance , spatially dependent electric and magnetic fields have been used to induce position dependent energy shifts on the atom @xcite , allowing for site - selective addressability .
alternatively , a scanning electron microscopy system to remove atoms from individual sites with a focused electron beam @xcite has been reported . however , in this case , atoms need to be reloaded into the emptied sites after each detection event . more recently , |
9,091 | Suppose that you have an abstract for a scientific paper: we present a practical implementation based on newton s method to find all roots of several families of complex polynomials of degrees up to @xmath0 million so that the observed complexity to find all roots is between @xmath1 and @xmath2 ( measuring complexity in terms of number of newton iterations or computing time ) .
all computations were performed successfully on standard personal computers made in 2010/2011 , using only a single processor core . .
And you have already written the first three sentences of the full article: it has been known since gauss that every complex polynomial @xmath3 in a single complex variable splits into linear factors , and since ruffini and abel that there is no method based on iterated @xmath4-th roots to find these factors algebraically in general .
therefore , numerical approximation methods are required to find the roots of polynomials .
( detail ) ..
Please generate the next two sentences of the article | the colors illustrate the number of iterations until a root is found to high precision ; adjacent color contour lines show a single iteration .
the scale is between 50 iterations ( red ) and 0 iterations ( dark blue ) ; bright green stands for 25 iterations . |
9,092 | Suppose that you have an abstract for a scientific paper: the notion of quantum discord introduced by ollivier and zurek [ phys .
rev .
lett * 88 * , 017901 ( 2001 ) ] ( see also henderson and vedral [ j. phys . a * 34 * , 6899 ( 2001 ) ] ) has attracted increasing attention , in recent years , as an entropic quantifier of non - classical features pertaining to the correlations exhibited by bipartite quantum systems . here
we generalize the notion so as to encompass power - law q - entropies ( that reduce to the standard shannon entropy in the limit @xmath0 ) and study the concomitant consequences .
the ensuing , new discord - like measures we advance describe aspects of non - classicality that are different from those associated with the standard quantum discord .
a particular manifestation of this difference concerns a feature related to order .
let @xmath1 stand for the standard , shannon - based discord measure and @xmath2 for the @xmath3 one .
if two quantum states @xmath4 are such that @xmath5 , this order - relation does not remain invariant under a change from @xmath1 to @xmath2 . .
And you have already written the first three sentences of the full article: the degree of understanding of quantum correlations ( qc ) underlies our current picture of nature @xcite .
it has been recently found that there exist important manifestations of the quantumness of correlations in composite systems that are different from those of entanglement - origin ( eo ) and that may be relevant in quantum information technologies @xcite .
the quantifier of these non - eo correlations is called the quantum discord ( qd ) @xmath1 and is based , for a bipartite system , on shannon s mutual information ..
Please generate the next two sentences of the article | we are thus speaking of an information - theoretic ( it ) tool .
for pure states qd does not add any qcs , but that is not the case for mixed states . |
9,093 | Suppose that you have an abstract for a scientific paper: we discuss the strength of the trilinear higgs boson coupling in technicolor ( or composite ) models in a model independent way . the coupling is determined as a function of a very general ansatz for the technicolor self - energy , and turns out to be equal or smaller than the one of the standard model higgs boson depending on the dynamics of the theory . with this trilinear coupling we estimate the cross section for higgs boson pair production at the lhc .
this measurement is quite improbable in the case of a heavy standard model higgs boson , but it will be even worse when this boson is dynamically generated .
@xmath0 ) .
And you have already written the first three sentences of the full article: in the standard model of elementary particles the fermion and gauge boson masses are generated due to the interaction of these particles with elementary higgs scalar bosons . despite its success
there are some points in the model as , for instance , the enormous range of masses between the lightest and heaviest fermions and other peculiarities that could be better explained at a deeper level .
the nature of the higgs boson is one of the most important problems in particle physics , and there are many questions that may be answered in the near future by the lhc experiments , such as : is the higgs boson , if it exists at all , elementary or composite ?.
Please generate the next two sentences of the article | what are the symmetries behind the higgs mechanism ? among the priorities of the higgs boson search at the lhc experiments , is the measurement of its mass , width , spin and cp eigenvalues .
the measurement of the higgs boson couplings and , particularly , its self - couplings will also be quite important , once they may unravel all the subtleties of the mechanism of electroweak symmetry breaking @xcite . it may be possible to measure the higgs boson self - coupling at the lhc in the case of a light higgs boson@xcite , but this will barely be possible if the boson mass is larger than @xmath1 gev . |
9,094 | Suppose that you have an abstract for a scientific paper: recently the chiral algebra of beilinson - drinfeld draws much attention in the mathematical physics of superstring theory .
naively , this is a holomorphic conformal field theory with integer graded conformal dimension , whose target space not necessarily has the vanishing first chern class .
this algebra has two ways of definition : one is that of malikov - schechtman - vaintrob by gluing affine patches , and the other is that of kapranov - vasserot by gluing the formal loop space .
we will use the method of malikov - schechtman - vaintrob in order to compute the gerbes of chiral differential operators . in this paper
, we will examine the two independent ansatzes of witten s ( 0,2 ) heterotic strings and nekrasov s generalized complex geometry are consistent in the case of @xmath0 , which has 3 affine patches and is expected to has the 1st pontrjagin anomaly .
we also extend this direction to the case of 2 dimensional toric fano manifolds ( toric del pezzo surfaces ) of all degrees , by blowing up the generic 1,2,3 points of @xmath0 .
these coincide with the computation of the hirzebruch riemann - roch theorem .
the most notable case is the 1 point blowup , where the total gauge invariant anomaly vanishes . the significant future direction towards its application to the geometric langlands program is also discussed in the last section .
beilinson - drinfeld chiral algebras for del pezzo surfaces 1.0 cm makoto sakurai + 0.5 cm _ department of physics , university of tokyo , 7 - 3 - 1 hongo , bunkyo - ku , tokyo 113 - 0033 , japan _ .
And you have already written the first three sentences of the full article: + + chiral de rham complex of beilinson and drinfeld @xcite is an attempt to extend conformal field theory ( cft ) to the case of target manifolds which do not necessarily obey the condition of the vanishing first chern class of tangent bundle @xmath1 .
we usually exclude such a situation from our consideration since non - linear sigma model on such a target manifold contains a logarithmic divergence and hence a non - vanishing beta function .
scale invariance will be lost in such a situation and one can not apply the method of cft . one way of realizing the idea of beilinson and drinfeld is to use the patchwise construction by malikov - schectman - vaintrob where one considers cft defined on each coordinate patch and then considers the consistency of the theory under coordinate transformation among different patches . in the case when the manifold is covered by , say , 4 patches @xmath2 , one first considers successive transformations @xmath3 . in the end.
Please generate the next two sentences of the article | one finds that under the total coordinate change @xmath4 the fields do not quite come back to their original values but there appears an additional term .
namely , there exists an obstruction or anomaly for a consistent cft in such a system . |
9,095 | Suppose that you have an abstract for a scientific paper: a high nmr detection sensitivity is indispensable when dealing with mass and volume - limited samples , or whenever a high spatial resolution is required .
the use of miniaturised rf coils is a proven way to increase sensitivity , but may be impractical and is not applicable to every experimental situation .
we present the use of magnetic lenses , denoted as lenz lenses due to their working principle , to focus the magnetic flux of a macroscopic rf coil into a smaller volume and thereby locally enhance the sensitivity of the nmr experiment at the expense of the total sensitive volume . besides focusing , such lenses facilitate re - guiding or re - shaping of magnetic fields much like optical lenses do with light beams . for the first time we experimentally demonstrate the use of lenz lenses in magnetic resonance and provide a compact mathematical description of the working principle . through simulations we show that optimal arrangements can be found . n.s .
and p.t.w contributed equally to this work . ] both nuclear magnetic resonance ( nmr ) spectroscopy and magnetic resonance imaging ( mri ) suffer from an inherently low sensitivity .
the signal strength is primarily determined by the equilibrium boltzmann distribution , with energy levels of the spin states just slightly above the thermal energy .
consequently , the limit of detection ( lod ) is up to ten orders of magnitude worse compared to other analytical techniques @xcite
. this fact severely limits the lowest detectable quantity in nmr spectroscopy and the highest achievable spatial resolution in mri , both being directly proportional to the signal - to - noise ratio ( snr ) of the experiment .
the snr , first derived by hoult and richards @xcite , is given by @xcite @xmath0 where @xmath1 is a scaling factor to account for the homogeneity of the radio - frequency ( rf ) coil employed , @xmath2 is the rf - coil s magnetic field strength , @xmath3 the unit current , @xmath4 the coil s sensitivity , @xmath5 the observed sample....
And you have already written the first three sentences of the full article: expressions are now derived for calculating the induced current within an arbitrary number of circular lenz lenses made from wires and placed within the incident magnetic field generated by an external rf coil .
note that , by the theory of reciprocity @xcite , the expressions may be used in an equivalent sense to describe a situation in which a distinct volume of precessing magnetisation induces current within the lenz lenses , which in turn induce current within the external rf coil .
that is , the lenz lenses and corresponding theory are applicable to both the excitation and receive chains of a conventional nmr ( or mri ) experiment ..
Please generate the next two sentences of the article | consider the simple arrangement of placing a single circular lenz lens coaxially at the midpoint between two elements of a helmholtz pair .
faraday s law of induction states that the electromotive force ( emf ) , @xmath20 , generated in the lens is equal to the negative rate of change of magnetic flux @xmath21 that it encloses : @xmath22 lenz s law states that the sense of the current induced is such that it opposes this flux , hence the minus sign in equation ( [ faraday ] ) . in the limit that the gap size between the elements connecting the outer and inner loops of the lens is zero , the flux impressed on the lens is equal to that enclosed by the outer loop minus that enclosed by the inner loop : @xmath23 where @xmath24 is the current in the helmholtz pair , @xmath25 is the mutual inductance between the outer loop of the lens ( @xmath26 ) and one element of the helmholtz pair , and a similar definition holds for @xmath27 ( @xmath28 ) . |
9,096 | Suppose that you have an abstract for a scientific paper: we discuss a gauge fixing of gravity coupled to a scalar field in spherical symmetry such that the hamiltonian is an integral over space of a local density . in a previous paper
we had presented it using ashtekar s new variables . here
we study it in metric variables .
we specify completely the initial - boundary value problem for ingoing gaussian pulses . .
And you have already written the first three sentences of the full article: spherically symmetric gravity coupled to a scalar field is a rich model , where one can test scenarios of black hole formation , the critical phenomena discovered by choptuik and hawking evaporation at the quantum level . for many years
the full quantization of the model resisted analysis , in part due to the complicated nature of the hamiltonian structure of the system .
initial attempts to study the problem were done by berger , chitre , nutku and moncrief @xcite and further developed by unruh @xcite ..
Please generate the next two sentences of the article | the resulting complicated nature of the gauge fixed hamiltonian led led unruh to say `` i present it here in the hope that someone else may be able to do something with it . ''
more recently , husain and winkler and daghigh , kunstatter and gegenberg @xcite , using painlev |
9,097 | Suppose that you have an abstract for a scientific paper: in order to investigate the rheological properties of viscoelastic fluids by mesoscopic hydrodynamics methods , we develop a multi - particle collision dynamics ( mpc ) model for a fluid of harmonic dumbbells .
the algorithm consists of alternating streaming and collision steps .
the advantage of the harmonic interactions is that the integration of the equations of motion in the streaming step can be performed analytically .
therefore , the algorithm is computationally as efficient as the original mpc algorithm for newtonian fluids .
the collision step is the same as in the original mpc method .
all particles are confined between two solid walls moving oppositely , so that both steady and oscillatory shear flows can be investigated .
attractive wall potentials are applied to obtain a nearly uniform density everywhere in the simulation box .
we find that both in steady and oscillatory shear flow , a boundary layer develops near the wall , with a higher velocity gradient than in the bulk .
the thickness of this layer is proportional to the average dumbbell size .
we determine the zero - shear viscosities as a function of the spring constant of the dumbbells and the mean free path .
for very high shear rates , a very weak `` shear thickening '' behavior is observed .
moreover , storage and loss moduli are calculated in oscillatory shear , which show that the viscoelastic properties at low and moderate frequencies are consistent with a maxwell fluid behavior .
we compare our results with a kinetic theory of dumbbells in solution , and generally find good agreement . .
And you have already written the first three sentences of the full article: it is the characteristic feature of soft matter systems that a macromolecular component of nano- to micrometer size is dispersed in a solvent of much smaller molecules .
the mesoscopic length scale of the dispersed component implies that crystalline phases have a very small shear modulus which roughly scales like the inverse of the third power of the structural length scale and that both crystalline and fluid phases are characterized by long structural relaxation times .
soft matter systems have therefore interesting dynamical properties , because the time scale of an external perturbation can easily become comparable with the intrinsic relaxation time of the dispersed macromolecules ..
Please generate the next two sentences of the article | one of the unique properties of soft matter is its viscoelastic behavior@xcite . due to the long structural relaxation time
, the internal degrees of freedom can not relax sufficiently fast in an oscillatory shear flow , so that there is some elastic restoring force which pushes the system back to its previous state . |
9,098 | Suppose that you have an abstract for a scientific paper: the entanglement properties of the phase transition in a two dimensional harmonic lattice , similar to the one observed in recent ion trap experiments , are discussed both , for finite number of particles and thermodynamical limit .
we show that for the ground state at the critical value of the trapping potential two entanglement measures , the negativity between two neighbouring sites and the block entropy for blocks of size 1 , 2 and 3 , change abruptly .
entanglement thus indicates quantum phase transitions in general ; not only in the finite dimensional case considered in @xcite . finally , we consider the thermal state and compare its exact entanglement with a temperature entanglement witness introduced in @xcite .
keywords : _ harmonic lattice , quantum phase transition , entanglement _ .
And you have already written the first three sentences of the full article: coupled harmonic chains with short and long range interactions are ubiquitous in science and engineering . their application to calculate the phononic heat capacity by einstein @xcite marks the birth of solid state physics . beyond physics ,
harmonic chains feature in chemistry and biology , where they are used to model behaviour of macro - molecules , such as dna @xcite and cell membranes @xcite . in the last decade
harmonic systems have been revised using techniques developed in quantum information science to study correlation properties in the quantum regime and particularly at small temperatures @xcite ..
Please generate the next two sentences of the article | thermodynamics has been very successful in characterising `` standard '' phase transitions that occur at finite temperature when a macroscopic parameter , such as pressure , is changed @xcite .
quantum phase transitions ( qpts ) appear at zero temperature @xcite and are due to the change of an external parameter , such as the trapping potential of an ion trap . |
9,099 | Suppose that you have an abstract for a scientific paper: the disk galaxy ugc8802 has high neutral gas content and a flat profile of star formation rate compared to other disk galaxies with similar stellar mass .
it also shows a steep metallicity gradient .
we construct a chemical evolution model to explore its growth history by assuming its disk grows gradually from continuous gas infall , which is shaped by a free parameter the infall - peak time . by adopting the recently observed molecular surface density related star formation law ,
we show that a late infall - peak time can naturally explain the observed high neutral gas content , while an inside - out disk formation scenario can fairly reproduce the steep oxygen abundance gradient .
our results show that most of the observed features of ugc8802 can be well reproduced by simply ` turning the knob ' on gas inflow with one single parameter , which implies that the observed properties of gas - rich galaxies could also be modelled in a similar way . .
And you have already written the first three sentences of the full article: understanding the content and distribution of cold gas in galaxies is an important step to understand the formation and evolution of galaxies .
ugc8802 is an interesting target selected from the _ galex arecibo sdss survey ( gass ) @xcite .
one interesting aspect is its cold gas content ..
Please generate the next two sentences of the article | ugc8802 is a disk galaxy with stellar mass @xmath0 , while its hi mass is estimated to be as high as @xmath1 @xcite and its molecular gas mass is only about one - tenth of its hi mass @xcite . compared to other disk galaxies in this stellar mass range , the high neutral gas content of ugc8802 is uncommon @xcite .
why ugc8802 has such high neutral gas fraction and how ugc8802 acquires its cold gas are still open questions @xcite . |
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