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0704.2101
Wataru Horiuchi
W. Horiuchi and Y. Suzuki
Momentum distribution and correlation of two-nucleon relative motion in $^6$He and $^6$Li
14 pages, 9 figures
Phys.Rev.C76:024311,2007
10.1103/PhysRevC.76.024311
null
nucl-th
null
The momentum distribution of relative motion between two nucleons gives information on the correlation in nuclei. The momentum distribution is calculated for both $^{6}$He and $^6$Li which are described in a three-body model of $\alpha$+$N$+$N$. The ground state solution for the three-body Hamiltonian is obtained accurately using correlated basis functions. The momentum distribution depends on the potential model for the $N$-$N$ interaction. With use of a realistic potential, the $^6$He momentum distribution exhibits a dip around 2 fm$^{-1}$ characteristic of $S$-wave motion. In contrast to this, the $^6$Li momentum distribution is very similar to that of the deuteron; no dip appears because it is filled with the $D$-wave component arising from the tensor force.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 06:18:25 GMT" } ]
2008-11-26T00:00:00
[ [ "Horiuchi", "W.", "" ], [ "Suzuki", "Y.", "" ] ]
0704.2102
Rodrigo Montes R
Rodrigo Ristow Montes
A Remark on Compact Minimal Surfaces in $S^5$ with Non-Negative Gaussian Curvature
null
null
null
null
math.DG math.SG
null
In this paper we classify compact minimal surfaces in $S^5$ with non-negative Gaussian curvature using the notion of a contact angle.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 06:13:06 GMT" } ]
2007-05-23T00:00:00
[ [ "Montes", "Rodrigo Ristow", "" ] ]
0704.2103
Christos N. Ktorides
A. I. Karanikas and C. N. Ktorides
Zig Zag symmetry in AdS/CFT duality
24 pages version to appear in EPJC
Eur.Phys.J.C54:159-168,2008
10.1140/epjc/s10052-007-0504-3
null
hep-th
null
The validity of the Bianchi identity, which is intimately connected with the zig zag symmetry, is established, for piecewise continuous contours, in the context of Polakov's gauge field-string connection in the large 'tHooft coupling limit, according to which the chromoelectric `string' propagates in five dimensions with its ends attached on a Wilson loop in four dimensions. An explicit check in the wavy line approximation is presented.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 06:38:00 GMT" }, { "version": "v2", "created": "Sun, 29 Jul 2007 10:18:54 GMT" }, { "version": "v3", "created": "Thu, 13 Sep 2007 10:00:49 GMT" }, { "version": "v4", "created": "Thu, 6 Dec 2007 08:54:05 GMT" } ]
2008-11-26T00:00:00
[ [ "Karanikas", "A. I.", "" ], [ "Ktorides", "C. N.", "" ] ]
0704.2104
Jouko Tervo
Jouko Tervo, Markku Nihtil\"a, Petri Kokkonen
On parametrization of linear pseudo-differential boundary value control systems
null
null
null
null
math.AP
null
The paper considers pseudo-differential boundary value control systems. The underlying operators form an algebra D with the help of which we are able to formulate typical boundary value control problems. The symbolic calculus gives tools to form e.g. compositions, formal adjoints, generalized right or left inverses and compatibility conditions. By a parametrizability we mean that for a given control system Au=0 one finds an operator S such that Au=0 if and only if u=Sf. The computation rules of D (or its appropriate subalgebra D') guarantee that in many applications S can be refinely analyzed or even explicitly calculated. We outline some methods of homological algebra for the study of parametrization S. Especially the projectivity of a certain factor module (defined by the system equations) implies the parametrizability. We give some examples to illustrate our computational methods.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 06:40:59 GMT" } ]
2007-05-23T00:00:00
[ [ "Tervo", "Jouko", "" ], [ "Nihtilä", "Markku", "" ], [ "Kokkonen", "Petri", "" ] ]
0704.2105
Sun Fangwen
F. W. Sun, B. H. Liu, Y. F. Huang, Y. S. Zhang, Z. Y. Ou, and G. C. Guo
Entanglement and interference between different degrees of freedom of photons states
11 pages and 2 figures
PHYSICAL REVIEW A 76, 063805 (2007)
10.1103/PhysRevA.76.063805
null
quant-ph
null
In this paper, photonic entanglement and interference are described and analyzed with the language of quantum information process. Correspondingly, a photon state involving several degrees of freedom is represented in a new expression based on the permutation symmetry of bosons. In this expression, each degree of freedom of a single photon is regarded as a qubit and operations on photons as qubit gates. The two-photon Hong-Ou-Mandel interference is well interpreted with it. Moreover, the analysis reveals the entanglement between different degrees of freedom in a four-photon state from parametric down conversion, even if there is no entanglement between them in the two-photon state. The entanglement will decrease the state purity and photon interference visibility in the experiments on a four-photon polarization state.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 06:43:29 GMT" }, { "version": "v2", "created": "Fri, 4 Jan 2008 00:43:57 GMT" } ]
2008-01-04T00:00:00
[ [ "Sun", "F. W.", "" ], [ "Liu", "B. H.", "" ], [ "Huang", "Y. F.", "" ], [ "Zhang", "Y. S.", "" ], [ "Ou", "Z. Y.", "" ], [ "Guo", "G. C.", "" ] ]
0704.2106
Alessandro Ardizzoni
A. Ardizzoni, C. Menini
Associated Graded Algebras and Coalgebras
null
null
null
null
math.CT math.QA
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the notion of associated graded coalgebra (algebra) of a bialgebra with respect to a subbialgebra (quotient bialgebra) and characterize those which are bialgebras of type one in the framework of abelian braided monoidal categories.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 06:55:01 GMT" }, { "version": "v2", "created": "Fri, 6 Jun 2008 15:27:56 GMT" }, { "version": "v3", "created": "Tue, 20 Jul 2010 07:54:20 GMT" } ]
2010-07-21T00:00:00
[ [ "Ardizzoni", "A.", "" ], [ "Menini", "C.", "" ] ]
0704.2107
Beatrice Bleile
Beatrice Bleile
Poincare Duality Pairs in Dimension Three
submitted, 22 pages
null
null
null
math.AT
null
We extend Hendriks' classification theorem and Turaev's realisation and splitting theorems for Poincare duality complexes in dimension three to the relative case of Poincare duality pairs. The results for Poincare duality complexes are recovered by restricting the results to the case of Poincare duality pairs with empty boundary. Up to oriented homotopy equivalence, three-dimensional Poincare duality pairs are classified by their fundamental triple consisting of the fundamental group system, the orientation character and the image of the fundamental class under the classifying map. Using the derived module category we provide necessary and sufficient conditions for a given triple to be realised by a three-dimensional Poincare duality pair. The results on classification and realisation yield splitting or decomposition theorems for three-dimensional Poincare duality pairs, that is, conditions under which a given three-dimensional Poincare duality pair decomposes as interior or boundary connected sum of two three-dimensional Poincare duality pairs.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 07:09:45 GMT" } ]
2007-05-23T00:00:00
[ [ "Bleile", "Beatrice", "" ] ]
0704.2108
Hyosun Kim
Hyosun Kim, Yasushi Nakajima, Hwankyung Sung, Dae-Sik Moon, and Bon-Chul Koo
A Near-Infrared Study of the Highly-Obscured Active Star-Forming Region W51B
12 pages, 10 eps figures, uses jkas.sty
J.KoreanAstron.Soc.40:17-28,2007
10.5303/JKAS.2007.40.1.017
null
astro-ph
null
We present wide-field JHKs-band photometric observations of the three compact HII regions G48.9-0.3, G49.0-0.3, and G49.2-0.3 in the active star-forming region W51B. The star clusters inside the three compact HII regions show the excess number of stars in the J-Ks histograms compared with reference fields. While the mean color excess ratio E(J-H)/E(H-Ks) of the three compact HII regions are similar to ~ 2.07, the visual extinctions toward them are somewhat different: ~ 17 mag for G48.9-0.3 and G49.0-0.3; ~ 23 mag for G49.2-0.3. Based on their sizes and brightnesses, we suggest that the age of each compact HII region is =< 2 Myr. The inferred total stellar mass, ~ 1.4 x 10^4 M_sun, of W51B makes it one of the most active star forming regions in the Galaxy with the star formation efficiency of ~ 10 %.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 08:03:43 GMT" } ]
2017-01-18T00:00:00
[ [ "Kim", "Hyosun", "" ], [ "Nakajima", "Yasushi", "" ], [ "Sung", "Hwankyung", "" ], [ "Moon", "Dae-Sik", "" ], [ "Koo", "Bon-Chul", "" ] ]
0704.2109
Roberto Tateo
Patrick Dorey, Clare Dunning, Davide Masoero, Junji Suzuki and Roberto Tateo
ABCD and ODEs
12 pages, 9 figures, Latex, Contribution to the Proceedings of ICMP 2006, Rio de Janeiro
null
null
null
hep-th
null
We outline a relationship between conformal field theories and spectral problems of ordinary differential equations, and discuss its generalisation to models related to classical Lie algebras.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 09:26:24 GMT" } ]
2007-05-23T00:00:00
[ [ "Dorey", "Patrick", "" ], [ "Dunning", "Clare", "" ], [ "Masoero", "Davide", "" ], [ "Suzuki", "Junji", "" ], [ "Tateo", "Roberto", "" ] ]
0704.2110
Ekkehard Kruger
Ekkehard Kr\"uger
Stability of the superconducting state in YBa_2Cu_3O_7
null
J. Supercond. Nov. Magn. 23 , 213 (2010)
10.1007/s10948-009-0518-1
null
cond-mat.supr-con
null
The nonadiabatic Heisenberg model (NHM) proposed as an extension of the Heisenberg model makes a contribution to the eigenstate problem of superconductivity. The Hamiltonian H^n derived within this group-theoretical model has superconducting eigenstates if and only if the considered material possesses a narrow, roughly half-filled "superconducting" energy band of special symmetry in its band structure. This paper shows that the high-temperature superconductor YBa_2Cu_3O_7 possesses such a superconducting band. This new result together with previous observations about other superconductors and non-superconductors corroborates the theoretical evidence within the NHM that stable superconducting states are connected with superconducting bands. It is proposed that the type of superconductivity, i.e., whether the material is a conventional low-T_c or a high-T_c superconductor, is determined by the energetically lowest boson excitations that carry the crystal spin 1*hbar and are sufficiently stable to transport this crystal spin-angular momentum through the crystal. This mechanism provides the electron-phonon mechanism that enters the BCS theory in conventional superconductors.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 08:32:32 GMT" } ]
2011-03-03T00:00:00
[ [ "Krüger", "Ekkehard", "" ] ]
0704.2111
Tetsuji Kimura
Tetsuji Kimura
Index Theorems on Torsional Geometries
45 pages, the version to appear in JHEP
JHEP0708:048,2007
10.1088/1126-6708/2007/08/048
YITP-07-20
hep-th math.DG
null
We study various topological invariants on a torsional geometry in the presence of a totally anti-symmetric torsion H under the closed condition dH = 0, which appears in string theory compactification scenarios. By using the identification between the Clifford algebra on the geometry and the canonical quantization condition of fermions in quantum mechanics, we construct N=1 quantum mechanical sigma model in the Hamiltonian formalism. We extend this model to N=2 system, equipped with the totally anti-symmetric tensor associated with the torsion on the target space geometry. Next we construct transition elements in the Lagrangian path integral formalism and apply them to the analyses of the Witten indices in supersymmetric systems. We explicitly show the formulation of the Dirac index on the torsional manifold which has already been studied. We also formulate the Euler characteristic and the Hirzebruch signature on the torsional manifold.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 08:58:46 GMT" }, { "version": "v2", "created": "Tue, 24 Apr 2007 12:49:08 GMT" }, { "version": "v3", "created": "Tue, 26 Jun 2007 17:29:47 GMT" }, { "version": "v4", "created": "Tue, 14 Aug 2007 15:57:40 GMT" } ]
2008-11-26T00:00:00
[ [ "Kimura", "Tetsuji", "" ] ]
0704.2112
Joachim Albrecht
J Albrecht, M Djupmyr, S Bruck
Universal temperature scaling of flux line pinning in high-temperature superconducting thin films
5 pages, 4 figures To be published in Journal of Physics: Condensed matter
null
10.1088/0953-8984/19/21/216211
null
cond-mat.supr-con
null
Dissipation-free current transport in high-temperature superconductors is one of the most crucial properties of this class of materials which is directly related to the effective inhibition of flux line movement by defect structures. In this respect epitaxially grown thin films of YBa2Cu3O7-d (YBCO) are proving to be the strongest candidates for many widescale applications that are close to realization. We show that the relation between different defect structures and flux line pinning in these films exhibits universal features which are clearly displayed in a detailed analysis of the temperature-dependent behaviour of local critical currents. This allows us to identify different pinning mechanisms at different temperatures to be responsible for the found critical currents. Additionally, the presence of grain boundaries with very low misorientation angles affects the temperature stability of the critical currents which has important consequences for future applications.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 08:53:44 GMT" } ]
2009-11-13T00:00:00
[ [ "Albrecht", "J", "" ], [ "Djupmyr", "M", "" ], [ "Bruck", "S", "" ] ]
0704.2113
Xuanming Ye
Xuanming Ye
The Jumping Phenomenon of the Dimensions of Cohomology Groups of Tangent Sheaf
null
null
null
null
math.AG math.DG
null
Let $X$ be a compact complex manifold, consider a small deformation $\phi: \mathcal{X} \to B$ of $X$, the dimensions of the cohomology groups of tangent sheaf $H^q(X_t,\mathcal{T}_{X_t})$ may vary under this deformation. This paper will study such phenomenons by studying the obstructions to deform a class in $H^q(X,\mathcal{T}_X)$ with the parameter $t$ and get the formula for the obstructions.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 11:26:33 GMT" } ]
2007-05-23T00:00:00
[ [ "Ye", "Xuanming", "" ] ]
0704.2114
A. Mary Selvam
A. M. Selvam
Universal spectrum for DNA base CG frequency distribution in Takifugu rubripes (Puffer fish) genome
32 pages, 8 figures
null
null
null
physics.gen-ph physics.bio-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The frequency distribution of DNA bases A, C, G, T exhibit fractal fluctuations ubiquitous to dynamical systems in nature. The power spectra of fractal fluctuations exhibit inverse power law form signifying long-range correlations between local (small-scale) and global (large-scale) perturbations. The author has developed a general systems theory based on classical statistical physics for fractal fluctuations which predicts that the probability distribution of eddy amplitudes and the variance (square of eddy amplitude)spectrum of fractal fluctuations follow the universal Boltzmann inverse power law expressed as a function of the golden mean. The model predicted distribution is very close to statistical normal distribution for fluctuations within two standard deviations from the mean and exhibits a fat long tail. In this paper it is shown that DNA base CG frequency distribution in Takifugu rubripes (Puffer fish) Genome Release 4 exhibit universal inverse power law form consistent with model prediction. The observed long-range correlations in the DNA bases implies that the non-coding 'junk' or 'selfish' DNA which appear to be redundant, may also contribute to the efficient functioning of the protein coding DNA, a result supported by recent studies.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 09:13:19 GMT" }, { "version": "v2", "created": "Fri, 4 Mar 2011 09:06:27 GMT" } ]
2011-03-07T00:00:00
[ [ "Selvam", "A. M.", "" ] ]
0704.2115
Sitabhra Sinha
Sitabhra Sinha and Raj Kumar Pan
Uncovering the Internal Structure of the Indian Financial Market: Cross-correlation behavior in the NSE
15 pages, 8 figures, to appear in Proceedings of International Workshop on "Econophysics & Sociophysics of Markets & Networks" (Econophys-Kolkata III), Mar 12-15, 2007
Econophysics of Markets and Business Networks, (Springer, Milan, 2007) p. 3-19
10.1007/978-88-470-0665-2_1
null
q-fin.ST cond-mat.other physics.data-an physics.soc-ph
null
The cross-correlations between price fluctuations of 201 frequently traded stocks in the National Stock Exchange (NSE) of India are analyzed in this paper. We use daily closing prices for the period 1996-2006, which coincides with the period of rapid transformation of the market following liberalization. The eigenvalue distribution of the cross-correlation matrix, $\mathbf{C}$, of NSE is found to be similar to that of developed markets, such as the New York Stock Exchange (NYSE): the majority of eigenvalues fall within the bounds expected for a random matrix constructed from mutually uncorrelated time series. Of the few largest eigenvalues that deviate from the bulk, the largest is identified with market-wide movements. The intermediate eigenvalues that occur between the largest and the bulk have been associated in NYSE with specific business sectors with strong intra-group interactions. However, in the Indian market, these deviating eigenvalues are comparatively very few and lie much closer to the bulk. We propose that this is because of the relative lack of distinct sector identity in the market, with the movement of stocks dominantly influenced by the overall market trend. This is shown by explicit construction of the interaction network in the market, first by generating the minimum spanning tree from the unfiltered correlation matrix, and later, using an improved method of generating the graph after filtering out the market mode and random effects from the data. Both methods show, compared to developed markets, the relative absence of clusters of co-moving stocks that belong to the same business sector. This is consistent with the general belief that emerging markets tend to be more correlated than developed markets.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 10:52:05 GMT" } ]
2012-01-11T00:00:00
[ [ "Sinha", "Sitabhra", "" ], [ "Pan", "Raj Kumar", "" ] ]
0704.2116
A. de Visser
N.T. Huy, A. Gasparini, J.C.P. Klaasse, A. de Visser, S. Sakarya, N.H. van Dijk
Ferromagnetic quantum critical point in URhGe doped with Ru
5 pages; accepted for publication in Phys. Rev. B
Phys. Rev. B 75 (2007) 212405-1:4.
10.1103/PhysRevB.75.212405
null
cond-mat.str-el
null
We have investigated the thermal, transport and magnetic properties of URh$_{1-x}$Ru$_x$Ge alloys near the critical concentration $x_{cr} = 0.38$ for the suppression of ferromagnetic order. The Curie temperature vanishes linearly with $x$ and the ordered moment $m_0$ is suppressed in a continuous way. At $x_{cr}$ the specific heat varies as $c \sim TlnT$, the $\gamma$-value $c/T|_{0.5K}$ is maximum and the temperature exponent of the resistivity $\rho \sim T^n$ attains a minimum value $n=1.2$. These observations provide evidence for a ferromagnetic quantum phase transition. Interestingly, the coefficient of thermal expansion and the Gr\"uneisen parameter $\Gamma$ remain finite at $x_{cr}$ (down to $T = 1$ K), which is at odds with recent scaling results for a metallic quantum critical point.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 09:18:32 GMT" } ]
2009-11-13T00:00:00
[ [ "Huy", "N. T.", "" ], [ "Gasparini", "A.", "" ], [ "Klaasse", "J. C. P.", "" ], [ "de Visser", "A.", "" ], [ "Sakarya", "S.", "" ], [ "van Dijk", "N. H.", "" ] ]
0704.2117
Atushi Tanaka
Atushi Tanaka and Manabu Miyamoto
Quasienergy anholonomy and its application to adiabatic quantum state manipulation
10pages, 1figure. To be published in Phys. Rev. Lett.
Phys. Rev. Lett. 98, 160407 (2007)
10.1103/PhysRevLett.98.160407
null
quant-ph
null
The parametric dependence of a quantum map under the influence of a rank-1 perturbation is investigated. While the Floquet operator of the map and its spectrum have a common period with respect to the perturbation strength $\lambda$, we show an example in which none of the quasienergies nor the eigenvectors obey the same period: After a periodic increment of $\lambda$, the quasienergy arrives at the nearest higher one, instead of the initial one, exhibiting an anholonomy, which governs another anholonomy of the eigenvectors. An application to quantum state manipulations is outlined.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 09:20:18 GMT" } ]
2007-05-23T00:00:00
[ [ "Tanaka", "Atushi", "" ], [ "Miyamoto", "Manabu", "" ] ]
0704.2118
Moneesh Upmanyu
M. Upmanyu, P. A. Martin and A. D. Rollett
Effect of non-linear interface kinetics on coarsening phenomena
4 pages, 2 figures, 1 table
null
null
null
cond-mat.mtrl-sci cond-mat.soft
null
Coarsening kinetics is usually described using a linear gradient approximation for the underlying interface migration (IM) rates, wherein the migration fluxes at the interfaces vary linearly with the driving force. Recent experimental studies have shown that coarsening of nanocrystalline interface microstructures is unexpectedly stable compared to conventional parabolic coarsening kinetics. Here, we show that during early stage coarsening of these microstructures, IM rates can develop a non-linear dependence on the driving force, the mean interface curvature. We derive the modified mean field law for coarsening kinetics. Molecular dynamics simulations of individual grain boundaries reveal a sub-linear curvature dependence of IM rates, suggesting an intrinsic origin for the slow coarsening kinetics observed in polycrystalline metals.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 09:29:56 GMT" } ]
2007-05-23T00:00:00
[ [ "Upmanyu", "M.", "" ], [ "Martin", "P. A.", "" ], [ "Rollett", "A. D.", "" ] ]
0704.2119
Christian B\"ar
Christian Baer
Conformal Structures in Noncommutative Geometry
8 pages, published version
J. Noncomm. Geom. 1 (2007), 385-395
null
null
math.DG
null
It is well-known that a compact Riemannian spin manifold can be reconstructed from its canonical spectral triple which consists of the algebra of smooth functions, the Hilbert space of square integrable spinors and the Dirac operator. It seems to be a folklore fact that the metric can be reconstructed up to conformal equivalence if one replaces the Dirac operator D by sign(D). We give a precise formulation and proof of this fact.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 09:22:39 GMT" }, { "version": "v2", "created": "Fri, 4 May 2007 11:11:15 GMT" }, { "version": "v3", "created": "Fri, 15 Jun 2007 16:28:50 GMT" } ]
2011-11-09T00:00:00
[ [ "Baer", "Christian", "" ] ]
0704.2120
Ariane Lan\c{c}on
A. Lan\c{c}on, P.H. Hauschildt, D. Ladjal and M. Mouhcine
Near-IR Spectra of Red Supergiants and Giants. I- Models with Solar and with Mixing-Induced Surface Abundance Ratios
To be published in A&A. 19 p., 35 postscript figures, uses aa.cls. Selected model spectra available through CDS
null
10.1051/0004-6361:20065824
null
astro-ph
null
We provide a grid of PHOENIX spectra of red giant and supergiant stars, that extend through optical and near-IR wavelengths. For the first time, models are also provided with modified surface abundances of C, N and O, as a step towards accounting for the changes known to occur due to convective dredge-up (and to be enhanced in the case of rotation). The aims are (i) to assess how well current models reproduce observed spectra, (ii) to quantify the effects of the abundance changes on the spectra, and (iii) to determine how these changes affect estimates of fundamental stellar parameters. Observed giant star spectra can be fitted very well at solar metallicity down to about 3400K. Modified surface abundances are preferred in only a minority of cases for luminosity class II, possibly indicating mixing in excess of standard first dredge-up. Supergiant stars show a larger variety of near-IR spectra, and good fits are currently obtained for about one third of the observations only. Modified surface abundances help reproducing strong CN bands, but do not suffice to resolve all the difficulties. The effect of the abundance changes on the estimated Teff depends on the wavelength range of observation and can amount several 100K. Reasons for the remaining discrepancies are discussed.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 09:25:35 GMT" } ]
2009-11-13T00:00:00
[ [ "Lançon", "A.", "" ], [ "Hauschildt", "P. H.", "" ], [ "Ladjal", "D.", "" ], [ "Mouhcine", "M.", "" ] ]
0704.2121
Dmitry Pelinovsky
Dmitry Pelinovsky and Guido Schneider
Justification of the coupled-mode approximation for a nonlinear elliptic problem with a periodic potential
18 pages, no figures
null
10.1007/s00220-008-0640-0
null
math.AP math-ph math.MP nlin.PS
null
Coupled-mode systems are used in physical literature to simplify the nonlinear Maxwell and Gross-Pitaevskii equations with a small periodic potential and to approximate localized solutions called gap solitons by analytical expressions involving hyperbolic functions. We justify the use of the one-dimensional stationary coupled-mode system for a relevant elliptic problem by employing the method of Lyapunov--Schmidt reductions in Fourier space. In particular, existence of periodic/anti-periodic and decaying solutions is proved and the error terms are controlled in suitable norms. The use of multi-dimensional stationary coupled-mode systems is justified for analysis of bifurcations of periodic/anti-periodic solutions in a small multi-dimensional periodic potential.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 09:26:26 GMT" } ]
2009-11-13T00:00:00
[ [ "Pelinovsky", "Dmitry", "" ], [ "Schneider", "Guido", "" ] ]
0704.2122
Sixia Yu
Sixia Yu, Qing Chen, C. H. Lai, and C. H. Oh
Nonadditive quantum error-correcting code
1 eps figure
null
10.1103/PhysRevLett.101.090501
null
quant-ph
null
We report the first nonadditive quantum error-correcting code, namely, a $((9,12,3))$ code which is a 12-dimensional subspace within a 9-qubit Hilbert space, that outperforms the optimal stabilizer code of the same length by encoding more levels while correcting arbitrary single-qubit errors.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 09:30:17 GMT" } ]
2009-11-13T00:00:00
[ [ "Yu", "Sixia", "" ], [ "Chen", "Qing", "" ], [ "Lai", "C. H.", "" ], [ "Oh", "C. H.", "" ] ]
0704.2123
Dmitry Pelinovsky
Dmitry Pelinovsky and Guido Schneider
Moving gap solitons in periodic potentials
22 pages, 2 figures
null
10.1002/mma.1002
null
math.AP math.DS nlin.PS
null
We address existence of moving gap solitons (traveling localized solutions) in the Gross-Pitaevskii equation with a small periodic potential. Moving gap solitons are approximated by the explicit localized solutions of the coupled-mode system. We show however that exponentially decaying traveling solutions of the Gross-Pitaevskii equation do not generally exist in the presence of a periodic potential due to bounded oscillatory tails ahead and behind the moving solitary waves. The oscillatory tails are not accounted in the coupled-mode formalism and are estimated by using techniques of spatial dynamics and local center-stable manifold reductions. Existence of bounded traveling solutions of the Gross--Pitaevskii equation with a single bump surrounded by oscillatory tails on a finite large interval of the spatial scale is proven by using these technique. We also show generality of oscillatory tails in other nonlinear equations with a periodic potential.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 09:30:42 GMT" } ]
2009-11-13T00:00:00
[ [ "Pelinovsky", "Dmitry", "" ], [ "Schneider", "Guido", "" ] ]
0704.2124
Alexander Prygarin
M. Kozlov, E. Levin and A. Prygarin
The BFKL Pomeron Calculus in the dipole approach
28 pages, 3 figures
Nucl.Phys.A792:122-151,2007
10.1016/j.nuclphysa.2007.05.008
TAUP - 2854-07
hep-ph
null
In this paper we continue to pursue a goal of finding an effective theory for high energy interaction in QCD based on the colour dipole approach, for which the BFKL Pomeron Calculus gives a low energy limit. The key problem, that we try to solve in this paper is the probabilistic interpretation of the BFKL Pomeron Calculus in terms of the colourless dipoles and their interactions. We demonstrate that the BFKL Pomeron Calculus has two equivalent descriptions : (i) one is the generating functional which gives a clear probabilistic interpretation of the processes of high energy scattering and also provides a Hamiltonian-like description of the system of interacting dipoles; (ii) the second is the Langevin equation with a specific noise term which is rather complicated. We found that at high energies this Langevin equation can be reduced to the Langevin equation for directed percolation in the momentum space if the impact parameter is large, namely, $b>> 1/k$, where $k$ is the transverse momentum of a dipole. Unfortunately, this simplified form of Langevin equation is not applicable for summation of Pomeron loops, where one integrates over all possible values of impact parameter. We show that the BFKL Pomeron calculus with two vertices (splitting $P\to P+P$ and merging $P+P\to P$ of Pomerons) can be interpreted as a system of colourless dipoles with two processes: the decay of one dipole into two and the merging of two dipoles into one dipole. However, a number of assumptions we have to make on the way to simplify the noise term in the Langevin equation and/or to apply the probabilistic interpretation, therefore, we can consider both of these approaches in the present form only as the QCD motivated models.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 10:08:33 GMT" }, { "version": "v2", "created": "Tue, 15 May 2007 14:08:00 GMT" } ]
2008-11-26T00:00:00
[ [ "Kozlov", "M.", "" ], [ "Levin", "E.", "" ], [ "Prygarin", "A.", "" ] ]
0704.2125
Vyacheslav Yukalov
V.I. Yukalov and E.P. Yukalova
Calculation of critical exponents by self-similar factor approximants
17 pages, 2 tables
Eur. Phys. J. B 55 (2007) 93-99
10.1140/epjb/e2007-00044-4
null
cond-mat.stat-mech hep-ph
null
The method of self-similar factor approximants is applied to calculating the critical exponents of the O(N)-symmetric phi^4 theory and of the Ising glass. It is demonstrated that this method, being much simpler than other known techniques of series summation in calculating the critical exponents, at the same time, yields the results that are in very good agreement with those of other rather complicated numerical methods. The principal advantage of the method of self-similar factor approximants is the combination of its extraordinary simplicity and high accuracy.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 09:35:34 GMT" } ]
2015-05-13T00:00:00
[ [ "Yukalov", "V. I.", "" ], [ "Yukalova", "E. P.", "" ] ]
0704.2126
Cosimo Bambi
Cosimo Bambi
Strange stars and the cosmological constant problem
15 pages, 3 figures. v2: reference added and typos corrected
JCAP 0706:006,2007
10.1088/1475-7516/2007/06/006
null
hep-ph astro-ph
null
The cosmological constant problem represents an evident tension between our present description of gravity and particle physics. Many solutions have been proposed, but experimental tests are always difficult or impossible to perform and present phenomenological investigations focus only on possible relations with the dark energy, that is with the accelerating expansion rate of the contemporary universe. Here I suggest that strange stars, if they exist, could represent an interesting laboratory to investigate this puzzle, since their equilibrium configuration is partially determined by the QCD vacuum energy density.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 09:39:37 GMT" }, { "version": "v2", "created": "Mon, 23 Apr 2007 16:57:42 GMT" } ]
2014-11-18T00:00:00
[ [ "Bambi", "Cosimo", "" ] ]
0704.2127
Nicolas Ressayre
Nicolas Ressayre (I3M)
Geometric Invariant Theory and Generalized Eigenvalue Problem
comments welcome
Inventiones mathematicae 180, 2 (2010) 389-441
10.1007/s00222-010-0233-3
null
math.AG math.RT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Let $H$ be a connected reductive subgroup of a complex connected reductive group $G$. Fix maximal tori and Borel subgroups of $H$ and $G$. Consider the pairs $(V,V')$ of irreducible representations of $H$ and $G$ such that $V$ is a submodule of $V'$. We are interested in the cone $LR(G,H)$ generated by the pairs of dominant weights of such a pair of representations. Our main result gives a minimal set of inequalities describing $LR(G,H)$ as a part of the dominant chamber. In way, we obtain results about the faces of the Dolgachev-Hu's $G$-ample cone and variations of this cone.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 09:45:44 GMT" }, { "version": "v2", "created": "Wed, 7 Nov 2007 13:21:25 GMT" }, { "version": "v3", "created": "Mon, 2 Mar 2009 15:12:10 GMT" } ]
2010-09-15T00:00:00
[ [ "Ressayre", "Nicolas", "", "I3M" ] ]
0704.2128
J. M. B. Lopes dos Santos
J. M. B. Lopes dos Santos, N. M. R. Peres and A. H. Castro Neto
Graphene bilayer with a twist: electronic structure
4 pages, 3 eps figures
Phys. Rev Lett. 99 256802 (2007)
10.1103/PhysRevLett.99.256802
null
cond-mat.mtrl-sci
null
Electronic properties of bilayer and multilayer graphene have generally been interpreted in terms of AB or Bernal stacking. However, it is known that many types of stacking defects can occur in natural and synthetic graphite; rotation of the top layer is often seen in scanning tunneling microscopy (STM) studies of graphite. In this paper we consider a graphene bilayer with a relative small angle rotation between the layers and calculate the electronic structure near zero energy in a continuum approximation. Contrary to what happens in a AB stacked bilayer and in accord with observations in epitaxial graphene we find: (a) the low energy dispersion is linear, as in a single layer, but the Fermi velocity can be significantly smaller than the single layer value; (b) an external electric field, perpendicular to the layers, does not open an electronic gap
[ { "version": "v1", "created": "Tue, 17 Apr 2007 09:55:03 GMT" } ]
2011-11-09T00:00:00
[ [ "Santos", "J. M. B. Lopes dos", "" ], [ "Peres", "N. M. R.", "" ], [ "Neto", "A. H. Castro", "" ] ]
0704.2129
Denis Pilipenko
E. A. Brener, C. H\"uter, D. Pilipenko, D. E. Temkin
Velocity selection problem in the presence of the triple junction
null
null
10.1103/PhysRevLett.99.105701
null
cond-mat.mtrl-sci
null
Melting of a bicrystal along the grain boundary is discussed. A triple junction plays a crucial role in the velocity selection problem in this case. In some range of the parameters an entirely analytical solution of this problem is given. This allows to present a transparent picture of the structure of the selection theory. We also discuss the selection problem in the case of the growth of a ``eutectoid dendrite'' where a triple junction is present because three phases are involved in the eutectoid reaction.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 10:16:23 GMT" } ]
2009-11-13T00:00:00
[ [ "Brener", "E. A.", "" ], [ "Hüter", "C.", "" ], [ "Pilipenko", "D.", "" ], [ "Temkin", "D. E.", "" ] ]
0704.2130
Ru-Nan Huang
Yi-Shi Duan and Ru-Nan Huang
Vortices in Quantum R\"ontgen Effect
10 pages, no figure
null
null
null
cond-mat.other
null
By the application of $\phi$-mapping topological theory, the properties of vortices in quantum R\"ontgen effect is thoroughly studied. The explicit expression of the vorticity is obtained, wherein which the $\delta$ function indicates that the vortices can only stem from the zero points of $\phi$ and the magnetic flux of the consequent monopoles is quantized in terms of the Hopf indices and Brouwer degrees. The evolution of vortex lines is discussed. The reduced dynamic equation and a conserved dynamic quantity on stable vortex lines are obtained.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 10:22:38 GMT" } ]
2007-05-23T00:00:00
[ [ "Duan", "Yi-Shi", "" ], [ "Huang", "Ru-Nan", "" ] ]
0704.2131
Giulia Migliori
G.Migliori, P.Grandi, G.G.C.Palumbo, G.Brunetti, C.Stanghellini
Radio Lobes of Pictor A: an X-ray spatially resolved Study
15 pages, 3 figures, ApJ accepted
null
10.1086/520870
null
astro-ph
null
A new XMM observation has made possible a detailed study of both lobes of the radio galaxy Pictor A. Their X-ray emission is of non thermal origin and due to Inverse Compton scattering of the microwave background photons by relativistic electrons in the lobes, as previously found. In both lobes, the equipartition magnetic field (Beq) is bigger than the Inverse Compton value (Bic), calculated from the radio and X-ray flux ratio. The Beq/Bic ratio never gets below 2, in spite of the large number of reasonable assumptions tested to calculate Beq, suggesting a lobe energetic dominated by particles. The X-ray data quality is good enough to allow a spatially resolved analysis. Our study shows that Bic varies through the lobes. It appears to increase behind the hot spots. On the contrary, a rather uniform distribution of the particles is observed. As a consequence, the radio flux density variation along the lobes appears to be mainly driven by magnetic field changes.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 10:27:06 GMT" }, { "version": "v2", "created": "Fri, 15 Jun 2007 12:38:05 GMT" } ]
2009-11-13T00:00:00
[ [ "Migliori", "G.", "" ], [ "Grandi", "P.", "" ], [ "Palumbo", "G. G. C.", "" ], [ "Brunetti", "G.", "" ], [ "Stanghellini", "C.", "" ] ]
0704.2132
Roberto Chignola
C. Tomelleri, E. Milotti, C. Dalla Pellegrina, O. Perbellini, A. Del Fabbro, M. T. Scupoli and R. Chignola
A quantitative study on the growth variability of tumour cell clones in vitro
31 pages, 5 figures
null
null
null
q-bio.CB q-bio.QM
null
Objectives: In this study, we quantify the growth variability of tumour cell clones from a human leukemia cell line. Materials and methods: We have used microplate spectrophotometry to measure the growth kinetics of hundreds of individual cell clones from the Molt3 cell line. The growth rate of each clonal population has been estimated by fitting experimental data with the logistic equation. Results: The growth rates were observed to vary among different clones. Up to six clones with a growth rate above or below the mean growth rate of the parent population were further cloned and the growth rates of their offsprings were measured. The distribution of the growth rates of the subclones did not significantly differ from that of the parent population thus suggesting that growth variability has an epigenetic origin. To explain the observed distributions of clonal growth rates we have developed a probabilistic model assuming that the fluctuations in the number of mitochondria through successive cell cycles are the leading cause of growth variability. For fitting purposes, we have estimated experimentally by flow cytometry the maximum average number of mitochondria in Molt3 cells. The model fits nicely the observed distributions of growth rates, however, cells in which the mitochondria were rendered non functional (rho-0 cells) showed only a 30% reduction in the clonal growth variability with respect to normal cells. Conclusions: A tumor cell population is a dynamic ensemble of clones with highly variable growth rate. At least part of this variability is due to fluctuations in the number of mitochondria.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 10:30:56 GMT" } ]
2007-05-23T00:00:00
[ [ "Tomelleri", "C.", "" ], [ "Milotti", "E.", "" ], [ "Pellegrina", "C. Dalla", "" ], [ "Perbellini", "O.", "" ], [ "Del Fabbro", "A.", "" ], [ "Scupoli", "M. T.", "" ], [ "Chignola", "R.", "" ] ]
0704.2133
P. Pickl
Peter Pickl, Detlef Duerr
Adiabatic Pair Creation
53 pages, 1 figure. Editorial changes on page 22 ff
null
10.1007/s00220-008-0530-5
null
math-ph math.MP
null
We give here the proof that pair creation in a time dependent potentials is possible. It happens with probability one if the potential changes adiabatically in time and becomes overcritical, that is when an eigenvalue enters the upper spectral continuum. The potential may be assumed to be zero at large negative and positive times. The rigorous treatment of this effect has been lacking since the pioneering work of Beck, Steinwedel and Suessmann in 1963 and Gershtein and Zeldovich in 1970.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 10:37:13 GMT" }, { "version": "v2", "created": "Wed, 20 Jun 2007 09:18:30 GMT" } ]
2009-11-13T00:00:00
[ [ "Pickl", "Peter", "" ], [ "Duerr", "Detlef", "" ] ]
0704.2134
Melania Del Santo
M. Del Santo, L. Sidoli, S. Mereghetti, A. Bazzano, A. Tarana, P. Ubertini
XMMU J174716.1-281048: a "quasi-persistent" very faint X-ray transient?
4 pages, 8 figures, accepted for publication in A&A Letters
null
10.1051/0004-6361:20077536
null
astro-ph
null
The X-ray transient XMMU J174716.1-281048 was serendipitously discovered with XMM-Newton in 2003. It lies about 0.9 degrees off the Galactic Centre and its spectrum shows a high absorption (~8 x 10E22 cm^(-2)). Previous X-ray observations of the source field performed in 2000 and 2001 did not detect the source, indicative of a quiescent emission at least two orders of magnitude fainter. The low luminosity during the outburst (~5 x 10E34 erg/s at 8 kpc) indicates that the source is a member of the ``very faint X-ray transients'' class. On 2005 March 22nd the INTEGRAL satellite caught a possible type-I X-ray burst from the new INTEGRAL source IGR J17464-2811, classified as fast X-ray transient. This source was soon found to be positionally coincident, within the uncertainties, with XMMU J174716.1-281048. Here we report data analysis of the X-ray burst observed with the IBIS and JEM-X telescopes and confirm the type-I burst nature. We also re-analysed XMM-Newton and Chandra archival observations of the source field. We discuss the implications of these new findings, particularly related to the source distance as well as the source classification.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 14:09:53 GMT" } ]
2009-11-13T00:00:00
[ [ "Del Santo", "M.", "" ], [ "Sidoli", "L.", "" ], [ "Mereghetti", "S.", "" ], [ "Bazzano", "A.", "" ], [ "Tarana", "A.", "" ], [ "Ubertini", "P.", "" ] ]
0704.2135
Alessandra Galli
G. Barbiellini (1,2), A. Galli (2,3), L. Amati (4), A. Celotti (5), R. Landi (4), F. Longo (1,2), N. Omodei (6) and M. Tavani (3) ((1)University of Trieste, (2)INFN of Trieste, (3)IASF of Rome/INAF, (4)IASF of Bologna/INAF, (5)SISSA, (6)INFN of Pisa)
Relativistic interaction of a high intensity photon beam with a plasma: a possible GRB emission mechanism
3 pages, no figure, to be published in "The Proceedings of the First International GLAST Symposium", February 5-8, 2007, Stanford University, AIP, Eds. S. Ritz, P. F. Michelson, and C. Meegan
AIPConf.Proc.921:265-267,2007
10.1063/1.2757318
null
astro-ph
null
A long duration photon beam can induce macroscopic coherent effects on a plasma by single photon electron scattering if the probability of the interaction approaches 1 in a volume of unit surface and length equal to the plasma typical wavelength, and the induced electron oscillations become relativistic in few plasma cycles. A fraction of the plasma electrons is accelerated through the Wakefield mechanism by the cavities created by the photon-electron interactions and radiates through boosted betraton emission in the same cavities. The resulting emission in this framework is very similar to the typical GRB radiation. Several comparisons with GRB light curves and spectral-energy correlations will be presented.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 11:21:05 GMT" } ]
2019-08-19T00:00:00
[ [ "Barbiellini", "G.", "" ], [ "Galli", "A.", "" ], [ "Amati", "L.", "" ], [ "Celotti", "A.", "" ], [ "Landi", "R.", "" ], [ "Longo", "F.", "" ], [ "Omodei", "N.", "" ], [ "Tavani", "M.", "" ] ]
0704.2136
Kyle Lane
K. P. Lane, O. Almaini, S. Foucaud, C. Simpson, Ian Smail, R. J. McLure, C. J. Conselice, M. Cirasuolo, M. J. Page, J. S. Dunlop, P. Hirst, M. G. Watson and K. Sekiguchi
The colour selection of distant galaxies in the UKIDSS Ultra-Deep Survey Early Data Release
Accepted for publication in MNRAS Letters. 5 pages, 5 figures, 1 table. Higher-resolution figures available from the authors on request
Mon.Not.Roy.Astron.Soc.Lett.379:L25-L29,2007
10.1111/j.1745-3933.2007.00327.x
null
astro-ph
null
We investigate colour selection techniques for high redshift galaxies in the UKIDSS Ultra Deep Survey Early Data Release (UDS EDR). Combined with very deep Subaru optical photometry, the depth (K_AB = 22.5) and area (0.62 deg^2) of the UDS EDR allows us to investigate optical/near-IR selection using a large sample of over 30,000 objects. By using the B-z, z-K colour-colour diagram (the BzK technique) we identify over 7500 candidate galaxies at z > 1.4, which can be further separated into passive and starforming systems (pBzK and sBzK respectively). Our unique sample allows us to identify a new feature not previously seen in BzK diagrams, consistent with the passively evolving track of early type galaxies at z < 1.4. We also compare the BzK technique with the R-K colour selection of Extremely Red Objects (EROs) and the J-K selection of Distant Red Galaxies (DRGs), and quantify the overlap between these populations. We find that the majority of DRGs, at these relatively bright magnitudes are also EROs. Since previous studies have found that DRGs at these magnitudes have redshifts of z ~ 1 we determine that these DRG/ERO galaxies have SEDs consistent with being dusty star-forming galaxies or AGN at z < 2. Finally we observe a flattening in the number counts of pBzK galaxies, similar to other studies, which may indicate that we are sampling the luminosity function of passive z > 1 galaxies over a narrow redshift range.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 17:07:13 GMT" } ]
2009-06-23T00:00:00
[ [ "Lane", "K. P.", "" ], [ "Almaini", "O.", "" ], [ "Foucaud", "S.", "" ], [ "Simpson", "C.", "" ], [ "Smail", "Ian", "" ], [ "McLure", "R. J.", "" ], [ "Conselice", "C. J.", "" ], [ "Cirasuolo", "M.", "" ], [ "Page", "M. J.", "" ], [ "Dunlop", "J. S.", "" ], [ "Hirst", "P.", "" ], [ "Watson", "M. G.", "" ], [ "Sekiguchi", "K.", "" ] ]
0704.2137
S. K. Roushon
S.K. Roushon
L-theory of groups with unstable derived series
4 pages, AMSLATEX file
null
null
null
math.KT math.GT
null
In this short note we prove that the Farrell-Jones Fibered Isomorphism Conjecture in L-theory, after inverting 2, is true for a group whose some derived subgroup is free.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 16:04:37 GMT" } ]
2007-05-23T00:00:00
[ [ "Roushon", "S. K.", "" ] ]
0704.2138
Marc Emanuel
Marc Emanuel, Herv\'e Mohrbach, Mehmet Sayar, Helmut Schiessel and Igor M. Kuli\'c
Semi-classical buckling of stiff polymers
Revtex, 17 pages, 4 figures
null
10.1103/PhysRevE.76.061907
null
cond-mat.soft
null
A quantitative theory of the buckling of a worm like chain based on a semi-classical approximation of the partition function is presented. The contribution of thermal fluctuations to the force-extension relation that allows to go beyond the classical Euler buckling is derived in the linear and non-linear regime as well. It is shown that the thermal fluctuations in the nonlinear buckling regime increase the end-to-end distance of the semiflexible rod if it is confined to 2 dimensions as opposed to the 3 dimensional case. Our approach allows a complete physical understanding of buckling in D=2 and in D=3 below and above the Euler transition.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 11:46:35 GMT" }, { "version": "v2", "created": "Wed, 18 Apr 2007 10:17:29 GMT" } ]
2016-08-14T00:00:00
[ [ "Emanuel", "Marc", "" ], [ "Mohrbach", "Hervé", "" ], [ "Sayar", "Mehmet", "" ], [ "Schiessel", "Helmut", "" ], [ "Kulić", "Igor M.", "" ] ]
0704.2139
Pradeep Kumar Mohanty
P. K. Mohanty
Why only few are so successful ?
8 pages, 3 eps figures, elsart.cls (included), accepted in Physica A
Physica A 384, 75 (2007)
10.1016/j.physa.2007.04.118
null
physics.pop-ph physics.soc-ph q-fin.GN
null
In many professons employees are rewarded according to their relative performance. Corresponding economy can be modeled by taking $N$ independent agents who gain from the market with a rate which depends on their current gain. We argue that this simple realistic rate generates a scale free distribution even though intrinsic ability of agents are marginally different from each other. As an evidence we provide distribution of scores for two different systems (a) the global stock game where players invest in real stock market and (b) the international cricket.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 12:07:15 GMT" } ]
2010-09-03T00:00:00
[ [ "Mohanty", "P. K.", "" ] ]
0704.2140
Simon P. Driver
Simon P. Driver, Cristina C. Popescu, Richard J. Tuffs, Jochen Liske, Alister W. Graham, Paul D. Allen, Roberto De Propris
The Millennium Galaxy Catalogue: the B-band attenuation of bulge and disc light and the implied cosmic dust and stellar mass densities
Accepted for publication in MNRAS (18 pages, 16 figures). This paper, the MGC data catalogues, and associated papers are available from the MGC website at http://www.eso.org/~jliske/mgc/
Mon.Not.Roy.Astron.Soc.379:1022-1036,2007
10.1111/j.1365-2966.2007.11862.x
null
astro-ph
null
Based on our sample of 10095 galaxies with bulge-disc decompositions we derive the empirical B-band internal attenuation--inclination relation for galaxy discs and their associated central bulges. Our results agree well with the independently derived dust models of Tuffs et al., leading to a direct constraint on the mean opacity of spiral discs of Tau_B^f = 3.8 +/- 0.7 (central face-on B-band opacity). Depending on inclination, the B-band attenuation correction varies from 0.2 -- 1.1 mag for discs and from 0.8 -- 2.6 mag for bulges. We find that, overall, 37 per cent of all B-band photons produced in discs in the nearby universe are absorbed by dust, a figure that rises to 71 per cent for bulge photons. The severity of internal dust extinction is such that one must incorporate internal dust corrections in all optical studies of large galaxy samples. This is particularly pertinent for optical HST comparative evolutionary studies as the dust properties will also be evolving. We use the new results to revise our recent estimates of the spheroid and disc luminosity functions. From our best fitting dust models we derive a redshift zero cosmic dust density of rho_{dust} ~ (5.3 +/- 1.7) x 10^5, h M_{odot} Mpc^-3. This implies that (0.0083 +/- 0.0027), h per cent of the baryons in the Universe are in the form of dust and (11.9 +/- 1.7), h per cent (Salpeter-`lite' IMF) are in the form of stars (~58 per cent reside in galaxy discs, ~10 per cent in red elliptical galaxies, ~29 per cent in classical galaxy bulges and the remainder in low luminosity blue spheroid systems/components). [Abridged]
[ { "version": "v1", "created": "Tue, 17 Apr 2007 12:12:53 GMT" } ]
2009-06-23T00:00:00
[ [ "Driver", "Simon P.", "" ], [ "Popescu", "Cristina C.", "" ], [ "Tuffs", "Richard J.", "" ], [ "Liske", "Jochen", "" ], [ "Graham", "Alister W.", "" ], [ "Allen", "Paul D.", "" ], [ "De Propris", "Roberto", "" ] ]
0704.2141
Andrey N. Timokhin
Andrey Timokhin
Differentially rotating force-free magnetosphere of an aligned rotator: analytical solutions in split-monopole approximation
15 pages, 15 figures; accepted for publication in MNRAS
Mon.Not.Roy.Astron.Soc.379:605-618,2007
10.1111/j.1365-2966.2007.11864.x
null
astro-ph
null
In this paper we consider stationary force-free magnetosphere of an aligned rotator when plasma in the open field line region rotates differentially due to presence of a zone with the accelerating electric field in the polar cap of pulsar. We study the impact of differential rotation on the current density distribution in the magnetosphere. Using split-monopole approximation we obtain analytical expressions for physical parameters of differentially rotating magnetosphere. We find the range of admitted current density distributions under the requirement that the potential drop in the polar cap is less than the vacuum potential drop. We show that the current density distribution could deviate significantly from the ``classical'' Michel distribution and could be made almost constant over the polar cap even when the potential drop in the accelerating zone is of the order of 10 per cents of the vacuum potential drop. We argue that differential rotation of the open magnetic field lines could play an important role in adjusting between the magnetosphere and the polar cap cascade zone and could affect the value of pulsar breaking index.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 12:14:49 GMT" } ]
2009-06-23T00:00:00
[ [ "Timokhin", "Andrey", "" ] ]
0704.2142
Pradeep Kumar Mohanty
P. K. Mohanty and Deepak Dhar
Critical Behavior of Sandpile Models with Sticky Grains
8 pages, 3 eps figures, accepted in Physica A, elsart.cls attached
Physica A 384, 34 (2007)
10.1016/j.physa.2007.04.117
null
cond-mat.stat-mech
null
We revisit the question whether the critical behavior of sandpile models with sticky grains is in the directed percolation universality class. Our earlier theoretical arguments in favor, supported by evidence from numerical simulations [ Phys. Rev. Lett., {\bf 89} (2002) 104303], have been disputed by Bonachela et al. [Phys. Rev. E {\bf 74} (2004) 050102] for sandpiles with no preferred direction. We discuss possible reasons for the discrepancy. Our new results of longer simulations of the one-dimensional undirected model fully support our earlier conclusions.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 12:27:32 GMT" } ]
2010-09-03T00:00:00
[ [ "Mohanty", "P. K.", "" ], [ "Dhar", "Deepak", "" ] ]
0704.2143
Alessio Fangano
A.P.M. Fangano, A. Ferrara and P. Richter
Absorption features of high redshift galactic winds
27 pages, 27 figures. Submitted to MNRAS. Full refereed version. Typos fixed, new comparisons with observational data added. Full resolution images are available at http://www.astro.uni-bonn.de/~fangano/winds.html
null
10.1111/j.1365-2966.2007.12220.x
null
astro-ph
null
The environment of high-redshift galaxies is characterized by both wind-driven outflowing gas and gravitationally infalling streams. To investigate such galaxy-IGM interplay we have generated synthetic optical absorption line spectra piercing the volume surrounding a starbursting analog of a Lyman Break Galaxy selected in a $z \approx 3$ output from a SPH simulation, including a detailed treatment of mechanical feedback from winds. Distributions for several observable species (HI, CIII, CIV, SiII, SiIII, SiIV, OVI, OVII, and OVIII) have been derived by post-processing the simulation outputs. The hot wind material is characterized by the presence of high-ionization species such as OVI, OVII, and OVIII (the latter two observable only in X-ray bands); the colder ($T<10^{5.5}$ K) infalling streams can be instead identified by the combined presence of SiII, SiIII, and CIII optical absorption together with OVI that surrounds the cooler gas clumps. However, both line profile and Pixel Optical Depth analysis of the synthetic spectra show that the intergalactic filament in which the wind-blowing galaxy is embedded produces absorption signatures that closely mimic those of the wind environment. We conclude that may be difficult to clearly identify wind-blowing galaxies and their complex gaseous environment at high redshift in optical QSO absorption-line spectra based solely on the observed ion absorption patterns.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 12:42:01 GMT" }, { "version": "v2", "created": "Mon, 11 Jun 2007 14:29:52 GMT" } ]
2019-08-19T00:00:00
[ [ "Fangano", "A. P. M.", "" ], [ "Ferrara", "A.", "" ], [ "Richter", "P.", "" ] ]
0704.2144
Guillaume Rond
Guillaume Rond
An algebraic proof of Gabrielov's theorem about analytic homomorphisms in any characteristic
The proof of proposition 3.6 is not correct
null
null
null
math.AC math.AG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The proof of proposition 3.6 is not correct
[ { "version": "v1", "created": "Tue, 17 Apr 2007 12:30:42 GMT" }, { "version": "v2", "created": "Tue, 25 Sep 2007 14:07:48 GMT" }, { "version": "v3", "created": "Mon, 2 Nov 2009 09:22:15 GMT" } ]
2009-11-02T00:00:00
[ [ "Rond", "Guillaume", "" ] ]
0704.2145
Katia Biazzo Dr
J. Setiawan (1), P. Weise (1), Th. Henning (1), A.P. Hatzes (2), L. Pasquini (3), L. da Silva (4), L. Girardi (5), O. von der Luhe (6), M.P. Dollinger (3), A. Weiss (7), K. Biazzo (3,8) ((1) MPIA-Heidelberg, (2) TLS, (3) ESO-Garching, (4) ON/MCT, (5) INAF-OAPd, (6) KIS, (7) MPIA-Garching, (8) INAF-OACt)
Planets around active stars
4 pages, 5 figures, to appear in the Proceedings of the ESO Workshop "Precision Spectroscopy in Astrophysics", eds. L. Pasquini, M. Romaniello, N.C. Santos, A. Correia
null
10.1007/978-3-540-75485-5_43
null
astro-ph
null
We present the results of radial velocity measurements of two samples of active stars. The first sample contains field G and K giants across the Red Giant Branch, whereas the second sample consists of nearby young stars (d < 150 pc) with ages between 10 - 300 Myrs. The radial velocity monitoring program has been carried out with FEROS at 1.52 m ESO telescope (1999 - 2002) and continued since 2003 at 2.2 m MPG/ESO telescope. We observed stellar radial velocity variations which originate either from the stellar activity or the presence of stellar/substellar companions. By means of a bisector technique we are able to distinguish the sources of the radial velocity variation. Among them we found few candidates of planetary companions, both of young stars and G-K giants sample.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 12:36:38 GMT" } ]
2009-11-13T00:00:00
[ [ "Setiawan", "J.", "" ], [ "Weise", "P.", "" ], [ "Henning", "Th.", "" ], [ "Hatzes", "A. P.", "" ], [ "Pasquini", "L.", "" ], [ "da Silva", "L.", "" ], [ "Girardi", "L.", "" ], [ "von der Luhe", "O.", "" ], [ "Dollinger", "M. P.", "" ], [ "Weiss", "A.", "" ], [ "Biazzo", "K.", "" ] ]
0704.2146
Italo Dejter Prof
Italo J. Dejter
Homogeneous edge-disjoint $K_{2s}$ and $T_{st,t}$ unions
23 pages, 1 table
null
null
null
math.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Let $r>2$ and $\sigma\in(0,r-1)$ be integers. We require $t<2s$, where $t=2^{\sigma+1}-1$ and $s=2^{r-\sigma-1}$. Generalizing a known $\{K_4,T_{6,3}\}$-ultrahomogenous graph $G_3^1$, we find that a finite, connected, undirected, arc-transitive graph $G_r^\sigma$ exists each of whose edges is shared by just two maximal subgraphs, namely a clique $X_0=K_{2s}$ and a $t$-partite regular-Tur\'an graph $X_1=T_{st,t}$ on $s$ vertices per part. Each copy $Y$ of $X_i$ ($i=0,1$) in $G_r^\sigma$ shares each edge with just one copy of $X_{1-i}$ and all such copies of $X_{1-i}$ are pairwise distinct. Moreover, $G_r^\sigma$ is an edge-disjoint union of copies of $X_i$, for $i=0,1$. We prove that $G_r^\sigma$ is $\{K_{2s},T_{st,t}\}$-homogeneous if $t<2s$, and just $\{T_{st,t}\}$-homogeneous otherwise, meaning that there is an automorphism of $G_r^\sigma$ between any two such copies of $X_i$ relating two preselected arcs.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 12:40:35 GMT" }, { "version": "v10", "created": "Wed, 5 Dec 2007 11:28:26 GMT" }, { "version": "v11", "created": "Fri, 7 Dec 2007 18:51:44 GMT" }, { "version": "v12", "created": "Sat, 15 Dec 2007 20:25:16 GMT" }, { "version": "v13", "created": "Mon, 20 Oct 2008 20:32:06 GMT" }, { "version": "v14", "created": "Sat, 1 Nov 2008 18:40:52 GMT" }, { "version": "v15", "created": "Wed, 5 Nov 2008 18:23:42 GMT" }, { "version": "v16", "created": "Wed, 23 Sep 2009 11:43:09 GMT" }, { "version": "v17", "created": "Fri, 25 Sep 2009 12:06:31 GMT" }, { "version": "v18", "created": "Mon, 6 Feb 2012 20:22:56 GMT" }, { "version": "v19", "created": "Mon, 13 Feb 2012 10:42:21 GMT" }, { "version": "v2", "created": "Wed, 18 Jul 2007 21:44:41 GMT" }, { "version": "v20", "created": "Fri, 16 Mar 2012 20:39:15 GMT" }, { "version": "v21", "created": "Mon, 3 Sep 2012 18:20:56 GMT" }, { "version": "v22", "created": "Tue, 11 Sep 2012 09:30:58 GMT" }, { "version": "v23", "created": "Mon, 17 Sep 2012 19:10:19 GMT" }, { "version": "v24", "created": "Mon, 8 Oct 2012 10:29:37 GMT" }, { "version": "v25", "created": "Mon, 15 Oct 2012 21:58:13 GMT" }, { "version": "v26", "created": "Sun, 21 Jul 2013 20:21:38 GMT" }, { "version": "v27", "created": "Thu, 7 Aug 2014 21:19:51 GMT" }, { "version": "v28", "created": "Sun, 19 Jul 2015 20:54:42 GMT" }, { "version": "v29", "created": "Sun, 9 Aug 2015 00:02:39 GMT" }, { "version": "v3", "created": "Thu, 19 Jul 2007 21:44:26 GMT" }, { "version": "v30", "created": "Tue, 24 Nov 2015 20:45:47 GMT" }, { "version": "v31", "created": "Sat, 12 Dec 2015 13:38:36 GMT" }, { "version": "v32", "created": "Sun, 3 Apr 2016 11:15:55 GMT" }, { "version": "v33", "created": "Sun, 6 Jun 2021 19:23:56 GMT" }, { "version": "v34", "created": "Fri, 2 Jul 2021 18:36:56 GMT" }, { "version": "v4", "created": "Sun, 22 Jul 2007 13:23:39 GMT" }, { "version": "v5", "created": "Mon, 23 Jul 2007 20:35:31 GMT" }, { "version": "v6", "created": "Wed, 7 Nov 2007 20:32:36 GMT" }, { "version": "v7", "created": "Mon, 12 Nov 2007 19:29:45 GMT" }, { "version": "v8", "created": "Mon, 26 Nov 2007 09:52:25 GMT" }, { "version": "v9", "created": "Tue, 4 Dec 2007 14:33:37 GMT" } ]
2021-07-06T00:00:00
[ [ "Dejter", "Italo J.", "" ] ]
0704.2147
Pavlo Grygorov
A. Shebeko, P. Grygorov
A simultaneous center-of-mass correction of nucleon density and momentum distributions in nuclei
4 figures. Accepted to Ukr.Phys.J
null
null
null
nucl-th
null
The approach exposed in the recent paper (A. Shebeko, P. Papakonstantinou, E. Mavrommatis, Eur. Phys. J. A 27, 143 (2006)) has been applied in studying center-of-mass motion effects on the nucleon density and momentum distributions in nuclei. We are focused upon effects due to the center-of-mass and short-range nucleon correlations embedded in translationally invariant ground-state wavefunctions. The latter are constructed in the so-called fixed center-of-mass approximation, starting with a Slater determinant wave function modified by some correlator (e.g., after Jastrow or Villars). It is shown how one can simplify evaluation of the corresponding expectation values that determine the distributions. The analytic expressions derived here involve the own "Tassie-Barker" factors for each distribution. As an illustration, numerical calculations have been carried out for the nucleus ^{4}He with the Slater determinant to describe the nucleon (1s)^4 configuration composed of single-particle orbitals which differ from harmonic oscillator ones at small distances. Such orbitals simulate somewhat short-range repulsion between nucleons. Special attention is paid to a simultaneous shrinking of the center--of--mass corrected density and momentum distributions compared to the purely (1s)^4 shell nontranslationally invariant ones.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 13:03:43 GMT" } ]
2007-05-23T00:00:00
[ [ "Shebeko", "A.", "" ], [ "Grygorov", "P.", "" ] ]
0704.2148
Carlos Rascon
A.O. Parry, C. Rascon, N.B. Wilding and R. Evans
Continuous Capillary Condensation
(4 pages, 2 figures). Phys Rev Lett (accepted)
null
null
null
cond-mat.stat-mech cond-mat.soft
null
We show that condensation in a capped capillary slit is a continuous interfacial critical phenomenon, related intimately to several other surface phase transitions. In three dimensions (3d), the adsorption and desorption branches correspond to the unbinding of the meniscus from the cap and opening, respectively and are equivalent to 2d-like complete-wetting transitions. For dispersion forces, the singularities on the two branches are distinct, owing to the different interplay of geometry and intermolecular forces. In 2d we establish precise connection, or covariance, with 2d critical-wetting and wedge-filling transitions, i.e. we establish that certain interfacial properties in very different geometries are identical. Our predictions of universal scaling and covariance in finite capillaries are supported by extensive Ising model simulation studies in 2d and 3d.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 13:32:26 GMT" } ]
2007-05-23T00:00:00
[ [ "Parry", "A. O.", "" ], [ "Rascon", "C.", "" ], [ "Wilding", "N. B.", "" ], [ "Evans", "R.", "" ] ]
0704.2149
Neretin Yurii A.
Helene Airault, Yuri A.Neretin
On action of the Virasoro algebra on the space of univalent functions
15p
Bull. Sci. Math. 132, No. 1, 27-39 (2008)
10.1016/j.bulsci.2007.05.001
ESI-1906
math.RT math-ph math.MP
null
We obtain explicit expressions for differential operators defining the action of the Virasoro algebra on the space of univalent functions. We also obtain an explicit Taylor decomposition for Schwarzian derivative and a formula for the Grunsky coefficients.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 13:32:59 GMT" } ]
2012-11-27T00:00:00
[ [ "Airault", "Helene", "" ], [ "Neretin", "Yuri A.", "" ] ]
0704.2150
Carlos Rascon
C. Rascon
Comment on "Liquids on Topologically Nanopatterned Surfaces"
(1 page, 1 figure). Phys. Rev. Lett. (accepted)
null
10.1103/PhysRevLett.98.199801
null
cond-mat.stat-mech cond-mat.soft
null
Comment on "Liquids on Topologically Nanopatterned Surfaces" by O. Gang et al, Phys. Rev. Lett. 95, 217801 (2005). See also an erratum published by O. Gang et al (Phys Rev Lett, to appear)
[ { "version": "v1", "created": "Tue, 17 Apr 2007 13:50:46 GMT" } ]
2009-11-13T00:00:00
[ [ "Rascon", "C.", "" ] ]
0704.2151
Ulrich Vogl
U. Vogl and M. Weitz
Spectroscopy of atomic rubidium at 500 bar buffer gas pressure: approaching the thermal equilibrium of dressed atom-light states
4 pages
null
10.1103/PhysRevA.78.011401
null
physics.atom-ph cond-mat.soft
null
We have recorded fluorescence spectra of the atomic rubidium D-lines in the presence of several hundreds of bars buffer gas pressure. With additional saturation broadening a spectral linewidth comparable to the thermal energy of the atoms in the heated gas cell is achieved. An intensity-dependent blue asymmetry of the spectra is observed, which becomes increasingly pronounced when extrapolating to infinitely high light intensity. We interpret our results as evidence for the dressed (coupled atom-light) states to approach thermal equilibrium.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 13:42:17 GMT" } ]
2009-11-13T00:00:00
[ [ "Vogl", "U.", "" ], [ "Weitz", "M.", "" ] ]
0704.2152
Benedetti Riccardo
Riccardo Benedetti, Francesco Bonsante
(2+1)-Einstein spacetimes of finite type
65 pages, the final version of this paper will appear in Handbook in Teichmuller theory (A. Papadopoulos, ed.), Volume II, EMS Publishing House, Zurich, 2008
null
null
null
math.DG
null
The aim of this survey is to give an overview on the geometry of Einstein maximal globally hyperbolic 2+1 spacetimes of arbitrary curvature, conatining a complete Cauchy surface of finite type. In particular a specialization to the finite type case of the canonicla Wick rotation-rescaling theory, previously developed by the authors, is provided. This includes, for arbitrary curvatures, parameterizations in terms of suitable measured geodesic laminations on open hyperbolic surfaces of finite type. The same geometric objects also parameterize complex projective structures on the surfaces. The coincidence of such parameter space is explained by means of geometric correlations between spacetimes of different curvatures and projective surfaces realized via canonical WR-rescaling along the cosmological times. We also specialize on AdS case mostly referring to recent results achieved by other authors. In particular we describe maximal causal extensions of AdS globally hyperbolic spacetimes and an AdS approach to the theory of earthquakes for hyperbolic surfaces of finite type. A general earthquake theorem is proved for the so called enhanced Teichmuller space. The case of spacetimes with conical timelike singularities is also treated.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 13:43:42 GMT" } ]
2007-05-23T00:00:00
[ [ "Benedetti", "Riccardo", "" ], [ "Bonsante", "Francesco", "" ] ]
0704.2153
Frederic Chapoton
Fr\'ed\'eric Chapoton (ICJ)
Free pre-Lie algebras are free as Lie algebras
14 pages
Canadian Mathematical Bulletin 53, 3 (2010) 425-437
10.4153/CMB-2010-063-2
null
math.RA math.QA
null
We prove that free pre-Lie algebras, when considered as Lie algebras, are free. Working in the category of S-modules, we define a natural filtration on the space of generators. We also relate the symmetric group action on generators with the structure of the anticyclic PreLie operad.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 13:45:30 GMT" } ]
2014-04-09T00:00:00
[ [ "Chapoton", "Frédéric", "", "ICJ" ] ]
0704.2154
Svetlana Boriskina
Svetlana V. Boriskina, Trevor M. Benson, Phillip Sewell
Photonic molecules made of matched and mismatched microcavities: new functionalities of microlasers and optoelectronic components
10 pages with 12 figures
Proc. SPIE, vol. 6452, 6452X, Feb. 2007
10.1117/12.714344
null
physics.optics
null
Photonic molecules, named by analogy with chemical molecules, are clusters of closely located electromagnetically interacting microcavities or "photonic atoms". As two or several microcavities are brought close together, their optical modes interact, and a rich spectrum of photonic molecule supermodes emerges, which depends both on geometrical and material properties of individual cavities and on their mutual interactions. Here, we discuss ways of controllable manipulation of photonic molecule supermodes, which improve or add new functionalities to microcavity-based optical components. We present several optimally-tuned photonic molecule designs for lowering thresholds of semiconductor microlasers, producing directional light emission, enhancing sensitivity of microcavity-based bio(chemical)sensors, and optimizing electromagnetic energy transfer around bends of coupled-cavity waveguides. Photonic molecules composed of identical microcavities as well as of microcavities with various degrees of size or material detuning are discussed. Microwave experiments on scaled photonic molecule structures are currently under way to confirm our theoretical predictions.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 19:56:47 GMT" } ]
2015-05-13T00:00:00
[ [ "Boriskina", "Svetlana V.", "" ], [ "Benson", "Trevor M.", "" ], [ "Sewell", "Phillip", "" ] ]
0704.2155
Stephan Duerr
N. Syassen, D. M. Bauer, M. Lettner, D. Dietze, T. Volz, S. D\"urr, and G. Rempe
Atom-molecule Rabi oscillations in a Mott insulator
null
PRL 99, 033201 (2007)
10.1103/PhysRevLett.99.033201
null
cond-mat.stat-mech
null
We observe large-amplitude Rabi oscillations between an atomic and a molecular state near a Feshbach resonance. The experiment uses 87Rb in an optical lattice and a Feshbach resonance near 414 G. The frequency and amplitude of the oscillations depend on magnetic field in a way that is well described by a two-level model. The observed density dependence of the oscillation frequency agrees with the theoretical expectation. We confirmed that the state produced after a half-cycle contains exactly one molecule at each lattice site. In addition, we show that for energies in a gap of the lattice band structure, the molecules cannot dissociate.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 13:58:51 GMT" }, { "version": "v2", "created": "Fri, 1 Jun 2007 11:46:55 GMT" } ]
2007-07-19T00:00:00
[ [ "Syassen", "N.", "" ], [ "Bauer", "D. M.", "" ], [ "Lettner", "M.", "" ], [ "Dietze", "D.", "" ], [ "Volz", "T.", "" ], [ "Dürr", "S.", "" ], [ "Rempe", "G.", "" ] ]
0704.2156
Pedro Bicudo
P. Bicudo, M. Cardoso, O. Oliveira
First study of the gluon-quark-antiquark static potential in SU(3) Lattice QCD
4 pages RevTeX, 4 figures
Phys.Rev.D77:091504,2008
10.1103/PhysRevD.77.091504
null
hep-lat hep-ph
null
We study the long distance interaction for hybrid hadrons, with a static gluon, a quark and an antiquark with lattice QCD techniques. A Wilson loop adequate to the static hybrid three-body system is developed and, using a 24^3 x 48 periodic lattice with beta=6.2 and a ~ 0.075 fm, two different geometries for the gluon-quark segment and the gluon-antiquark segment are investigated. When these segments are perpendicular, the static potential is compatible with confinement realized with a pair of fundamental strings, one linking the gluon to the quark and another linking the same gluon to the antiquark. When the segments are parallel and superposed, the total string tension is larger and agrees with the Casimir Scaling measured by Bali. This can be interpreted with a type-II superconductor analogy for the confinement in QCD, with repulsion of the fundamental strings and with the string tension of the first topological excitation of the string (the adjoint string) larger than the double of the fundamental string tension.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 14:55:34 GMT" } ]
2008-11-26T00:00:00
[ [ "Bicudo", "P.", "" ], [ "Cardoso", "M.", "" ], [ "Oliveira", "O.", "" ] ]
0704.2157
Lee Samuel Finn
T. Z. Summerscales, Adam Burrows, Christian D. Ott and Lee Samuel Finn
Maximum Entropy for Gravitational Wave Data Analysis: Inferring the Physical Parameters of Core-Collapse Supernovae
44 pages, 12 figures; accepted version scheduled to appear in Ap J 1 April 2008
Astrophys.J.678:1142-1157,2008
10.1086/528362
null
astro-ph
null
The gravitational wave signal arising from the collapsing iron core of a Type II supernova progenitor star carries with it the imprint of the progenitor's mass, rotation rate, degree of differential rotation, and the bounce depth. Here, we show how to infer the gravitational radiation waveform of a core collapse event from noisy observations in a network of two or more LIGO-like gravitational wave detectors and, from the recovered signal, constrain these source properties. Using these techniques, predictions from recent core collapse modeling efforts, and the LIGO performance during its S4 science run, we also show that gravitational wave observations by LIGO might have been sufficient to provide reasonable estimates of the progenitor mass, angular momentum and differential angular momentum, and depth of the core at bounce, for a rotating core collapse event at a distance of a few kpc.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 14:07:55 GMT" }, { "version": "v2", "created": "Fri, 14 Dec 2007 15:27:46 GMT" } ]
2011-03-28T00:00:00
[ [ "Summerscales", "T. Z.", "" ], [ "Burrows", "Adam", "" ], [ "Ott", "Christian D.", "" ], [ "Finn", "Lee Samuel", "" ] ]
0704.2158
Antoni Szczurek
Tomasz Pietrycki and Antoni Szczurek
Photon-jet correlations in $pp$ and $p \bar p$ collisions
14 pages, 17 figures
Phys.Rev.D76:034003,2007
10.1103/PhysRevD.76.034003
null
hep-ph
null
We compare results of the $k_t$-factorization approach and the next-to-leading order collinear-factorization approach for photon-jet correlations in $pp$ and $p \bar p$ collisions at RHIC and Tevatron energies. We discuss correlations in the azimuthal angle as well as in the two-dimensional space of transverse momentum of photon and jet. Different unintegrated parton distributions (UPDF) are included in the $k_t$-factorization approach. The results depend on UPDFs used. The standard collinear approach gives cross section comparable to the $k_t$-factorization approach. For correlations of the photon and any jet the NLO contributions dominate at relatively small azimuthal angles as well as for asymmetric transverse momenta. For correlations of the photon with the leading jet (the one having the biggest transverse momentum) the NLO approach gives zero contribution at $\phi_{-} < \pi/2$ which opens a possibility to study higher-order terms and/or UPDFs in this region.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 14:11:31 GMT" }, { "version": "v2", "created": "Fri, 20 Apr 2007 07:20:06 GMT" } ]
2008-11-26T00:00:00
[ [ "Pietrycki", "Tomasz", "" ], [ "Szczurek", "Antoni", "" ] ]
0704.2159
Keigo Fukumura
Keigo Fukumura and Demosthenes Kazanas
Accretion Disk Illumination in Schwarzschild and Kerr Geometries: Fitting Formulae
26 pages, 21 b/w figures, accepted for publication in the Astrophysical Journal as of 4/16/2007
Astrophys.J.664:14-25,2007
10.1086/518883
null
astro-ph
null
We describe the methodology and compute the illumination of geometrically thin accretion disks around black holes of arbitrary spin parameter $a$ exposed to the radiation of a point-like, isotropic source at arbitrary height above the disk on its symmetry axis. We then provide analytic fitting formulae for the illumination as a function of the source height $h$ and the black hole angular momentum $a$. We find that for a source on the disk symmetry axis and $h/M > 3$, the main effect of the parameter $a$ is allowing the disk to extend to smaller radii (approaching $r/M \to 1$ as $a/M \to 1$) and thus allow the illumination of regions of much higher rotational velocity and redshift. We also compute the illumination profiles for anisotropic emission associated with the motion of the source relative to the accretion disk and present the fractions of photons absorbed by the black hole, intercepted by the disk or escaping to infinity for both isotropic and anisotropic emission for $a/M=0$ and $a/M=0.99$. As the anisotropy (of a source approaching the disk) increases the illumination profile reduces (approximately) to a single power-law, whose index, $q$, because of absorption of the beamed photons by the black hole, saturates to a value no higher than $q \gtrsim 3$. Finally, we compute the fluorescence Fe line profiles associated with the specific illumination and compare them among various cases.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 14:15:40 GMT" } ]
2019-08-19T00:00:00
[ [ "Fukumura", "Keigo", "" ], [ "Kazanas", "Demosthenes", "" ] ]
0704.2160
Todd Hunter
D.Y. Kubo, T.R. Hunter, R.D. Christensen, P.I. Yamaguchi
Characterization of Instrumental Phase Stability
10 pages, 12 figures, presented in poster form in May 2006 at the SPIE conference: Astronomical Telescopes and Instrumentation 2006, in the section on Millimeter and Submillimeter Detectors and Instrumentation for Astronomy III
Proceedings of the SPIE, Volume 6275 (2006)
10.1117/12.672927
null
astro-ph
null
Atmospheric water vapor causes significant undesired phase fluctuations for the Submillimeter Array (SMA) interferometer, particularly in its highest frequency observing band of 690 GHz. One proposed solution to this atmospheric effect is to observe simultaneously at two separate frequency bands of 230 and 690 GHz. Although the phase fluctuations have a smaller magnitude at the lower frequency, they can be measured more accurately and on shorter timescales due to the greater sensitivity of the array to celestial point source calibrators at this frequency. In theory, we can measure the atmospheric phase fluctuations in the 230 GHz band, scale them appropriately with frequency, and apply them to the data in 690 band during the post-observation calibration process. The ultimate limit to this atmospheric phase calibration scheme will be set by the instrumental phase stability of the IF and LO systems. We describe the methodology and initial results of the phase stability characterization of the IF and LO systems.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 14:24:21 GMT" } ]
2007-05-23T00:00:00
[ [ "Kubo", "D. Y.", "" ], [ "Hunter", "T. R.", "" ], [ "Christensen", "R. D.", "" ], [ "Yamaguchi", "P. I.", "" ] ]
0704.2161
Francois Couchot
Francois Couchot (LMNO)
Localization of injective modules over arithmetical rings
null
Communications in Algebra 37, 10 (2009) 3418-3423
null
CinA-2009
math.RA
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is proved that localizations of injective $R$-modules of finite Goldie dimension are injective if $R$ is an arithmetical ring satisfying the following condition: for every maximal ideal $P$, $R_P$ is either coherent or not semicoherent. If, in addition, each finitely generated $R$-module has finite Goldie dimension, then localizations of finitely injective $R$-modules are finitely injective too. Moreover, if $R$ is a Pr\"ufer domain of finite character, localizations of injective $R$-modules are injective.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 14:30:46 GMT" }, { "version": "v2", "created": "Tue, 13 Oct 2009 09:12:42 GMT" } ]
2009-10-13T00:00:00
[ [ "Couchot", "Francois", "", "LMNO" ] ]
0704.2162
Anatoly Shabad
Anatoly E. Shabad (1) and Vladimir V. Usov (2) ((1) P.N. Lebedev Physics Institute, Moscow, Russia, (2) Center for Astrophysics, Weizmann Institute, Rehovot, Israel)
Modified Coulomb Law in a Strongly Magnetized Vacuum
Revtex 4, 4 pages, 2 figures
Phys.Rev.Lett.98:180403,2007
10.1103/PhysRevLett.98.180403
null
astro-ph hep-th physics.atom-ph
null
We study electric potential of a charge placed in a strong magnetic field B>>4.4x10^{13}G, as modified by the vacuum polarization. In such field the electron Larmour radius is much less than its Compton length. At the Larmour distances a scaling law occurs, with the potential determined by a magnetic-field-independent function. The scaling regime implies short-range interaction, expressed by Yukawa law. The electromagnetic interaction regains its long-range character at distances larger than the Compton length, the potential decreasing across the magnetic field faster than along. Correction to the nonrelativistic ground-state energy of a hydrogenlike atom is found. In the infinite-magnetic-field limit the modified potential becomes the Dirac delta-function plus a regular background. With this potential the ground-state energy is finite - the best pronounced effect of the vacuum polarization.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 15:15:04 GMT" } ]
2009-06-23T00:00:00
[ [ "Shabad", "Anatoly E.", "" ], [ "Usov", "Vladimir V.", "" ] ]
0704.2163
Fabio Clementi
C. Di Guilmi, F. Clementi, T. Di Matteo, M. Gallegati
Social networks and labour productivity in Europe: An empirical investigation
LaTeX2e; 18 pages with 3 figures; Journal of Economic Interaction and Coordination, in press
Journal of Economic Interaction and Coordination, Vol: 3, Issue: 1, June 2008, pp: 43-57
10.1007/s11403-008-0034-6
null
physics.soc-ph
null
This paper uses firm-level data recorded in the AMADEUS database to investigate the distribution of labour productivity in different European countries. We find that the upper tail of the empirical productivity distributions follows a decaying power-law, whose exponent $\alpha$ is obtained by a semi-parametric estimation technique recently developed by Clementi et al. (2006). The emergence of "fat tails" in productivity distribution has already been detected in Di Matteo et al. (2005) and explained by means of a model of social network. Here we show that this model is tested on a broader sample of countries having different patterns of social network structure. These different social attitudes, measured using a social capital indicator, reflect in the power-law exponent estimates, verifying in this way the existence of linkages among firms' productivity performance and social network.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 14:38:57 GMT" }, { "version": "v2", "created": "Wed, 18 Apr 2007 09:03:34 GMT" }, { "version": "v3", "created": "Mon, 5 Nov 2007 13:12:04 GMT" } ]
2009-01-31T00:00:00
[ [ "Di Guilmi", "C.", "" ], [ "Clementi", "F.", "" ], [ "Di Matteo", "T.", "" ], [ "Gallegati", "M.", "" ] ]
0704.2164
Hans Pirner
B. Floter, B. Z. Kopeliovich, H.J. Pirner, J. Raufeisen
Charmed Meson Production in Deep Inelastic Scattering
24 pages, 10 figures
Phys.Rev.D76:014009,2007
10.1103/PhysRevD.76.014009
USM-TH-211
hep-ph
null
Charmed meson production in semi-inclusive deep inelastic scattering is investigated in the color dipole formalism. The transverse momentum distributions are calculated. We find good agreement with the H1 data using a hard fragmentation function.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 14:40:31 GMT" }, { "version": "v2", "created": "Mon, 14 May 2007 10:11:39 GMT" } ]
2008-11-26T00:00:00
[ [ "Floter", "B.", "" ], [ "Kopeliovich", "B. Z.", "" ], [ "Pirner", "H. J.", "" ], [ "Raufeisen", "J.", "" ] ]
0704.2165
Per Osland
P. Osland and A. Vereshagin
CP violation in unpolarized e^+ e^- to charginos at one loop level
similar to Phys. Rev. D version, but corrected figs. 4, 5, 6 (factor four)
Phys.Rev.D76:036001,2007; Erratum-ibid.D76:036001,2007
10.1103/PhysRevD.76.036001
null
hep-ph
null
We study CP violation in e^+ e^- to \tilde\chi_i^+\tilde\chi_j^- in the framework of the MSSM. Though the cross section of this process is CP-even at the tree level even for polarized electron-positron beams, we show that it contains a CP-odd part at the one loop order and there are CP-odd observables that can in principle be measured even using unpolarized electron-positron beams. The relevant diagram calculations are briefly discussed and the results of selected (box) diagram computations are shown.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 14:45:58 GMT" }, { "version": "v2", "created": "Wed, 27 Jun 2007 19:15:04 GMT" }, { "version": "v3", "created": "Thu, 4 Oct 2007 11:48:11 GMT" } ]
2008-11-26T00:00:00
[ [ "Osland", "P.", "" ], [ "Vereshagin", "A.", "" ] ]
0704.2166
J. -F. Desmurs
J.-F. Desmurs, J. Alcolea, V. Bujarrabal, C. Sanchez Contreras, and F. Colomer
Water vapor and silicon monoxide maser observations in the protoplanetary nebula OH 231.8+4
5 pages, 1 figure, A&A accepted
null
10.1051/0004-6361:20066914
null
astro-ph
null
OH 231.8+4.2 is a well studied preplanetary nebula (pPN) around a binary stellar system that shows a remarkable bipolar outflow. To study the structure and kinematics of the inner 10-80 AU nebular regions we performed high-resolution observations of the H$_2$O 6$_{1,6}$--5$_{2,3}$ and $^{28}$SiO $v$=2, $J$=1--0 maser emissions with the Very Long Baseline Array. The absolute position of both emission distributions were recovered using the phase referencing technique, and accurately registered in HST optical images. H$_2$O maser clumps are found to be distributed in two areas of 20 mas in size spatially displaced by $\sim$60 milli-arcseconds along an axis oriented nearly north-south. SiO masers are tentatively found to be placed between the two H$_2$O maser emitting regions, probably indicating the position of the Mira component of the system. The SiO maser emission traces an inner equatorial component with a diameter of 12 AU, probably a disk rotating around the M-type star. Outwards, we detect in the H$_2$O data a pair of polar caps, separated by 80 AU. We believe that the inner regions of the nebula probably have been altered by the presence of the companion, leading to an equator-to-pole density contrast that may explain the lack of H$_2$O masers and strong SiO maser emission in the denser, equatorial regions.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 15:06:56 GMT" } ]
2009-11-13T00:00:00
[ [ "Desmurs", "J. -F.", "" ], [ "Alcolea", "J.", "" ], [ "Bujarrabal", "V.", "" ], [ "Contreras", "C. Sanchez", "" ], [ "Colomer", "F.", "" ] ]
0704.2167
Alexandre Belloni
Alexandre Belloni and Victor Chernozhukov
On the Computational Complexity of MCMC-based Estimators in Large Samples
36 pages, 2 figures
Ann. Statist. Volume 37, Number 4 (2009), 2011-2055
10.1214/08-AOS634
null
math.ST math.PR stat.CO stat.TH
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we examine the implications of the statistical large sample theory for the computational complexity of Bayesian and quasi-Bayesian estimation carried out using Metropolis random walks. Our analysis is motivated by the Laplace-Bernstein-Von Mises central limit theorem, which states that in large samples the posterior or quasi-posterior approaches a normal density. Using the conditions required for the central limit theorem to hold, we establish polynomial bounds on the computational complexity of general Metropolis random walks methods in large samples. Our analysis covers cases where the underlying log-likelihood or extremum criterion function is possibly non-concave, discontinuous, and with increasing parameter dimension. However, the central limit theorem restricts the deviations from continuity and log-concavity of the log-likelihood or extremum criterion function in a very specific manner. Under minimal assumptions required for the central limit theorem to hold under the increasing parameter dimension, we show that the Metropolis algorithm is theoretically efficient even for the canonical Gaussian walk which is studied in detail. Specifically, we show that the running time of the algorithm in large samples is bounded in probability by a polynomial in the parameter dimension $d$, and, in particular, is of stochastic order $d^2$ in the leading cases after the burn-in period. We then give applications to exponential families, curved exponential families, and Z-estimation of increasing dimension.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 14:48:08 GMT" }, { "version": "v2", "created": "Mon, 4 Aug 2008 13:43:39 GMT" }, { "version": "v3", "created": "Wed, 25 Jan 2012 03:16:04 GMT" } ]
2012-01-26T00:00:00
[ [ "Belloni", "Alexandre", "" ], [ "Chernozhukov", "Victor", "" ] ]
0704.2168
Ilja Makkonen
I. Makkonen, M. J. Puska
Energetics of positron states trapped at vacancies in solids
Submitted to Physical Review B on 17 April 2007. Revised version submitted on 6 July 2007
Physical Review B 76, 054119 (2007).
10.1103/PhysRevB.76.054119
null
cond-mat.mtrl-sci
null
We report a computational first-principles study of positron trapping at vacancy defects in metals and semiconductors. The main emphasis is on the energetics of the trapping process including the interplay between the positron state and the defect's ionic structure and on the ensuing annihilation characteristics of the trapped state. For vacancies in covalent semiconductors the ion relaxation is a crucial part of the positron trapping process enabling the localization of the positron state. However, positron trapping does not strongly affect the characteristic features of the electronic structure, e.g., the ionization levels change only moderately. Also in the case of metal vacancies the positron-induced ion relaxation has a noticeable effect on the calculated positron lifetime and momentum distribution of annihilating electron-positron pairs.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 14:54:48 GMT" }, { "version": "v2", "created": "Sat, 7 Jul 2007 16:57:54 GMT" } ]
2007-08-19T00:00:00
[ [ "Makkonen", "I.", "" ], [ "Puska", "M. J.", "" ] ]
0704.2169
Alexandru Oancea
Fr\'ed\'eric Bourgeois and Alexandru Oancea
An exact sequence for contact- and symplectic homology
Final version. Changes for v2: Proof of main theorem supplemented with detailed discussion of continuation maps. Description of degree -2 map rewritten with emphasis on asymptotic markers. Sec. 5.2 rewritten with emphasis on 0-dim. moduli spaces. Transversality discussion reorganized for clarity (now Remark 9). Various other minor modifications
null
10.1007/s00222-008-0159-1
null
math.SG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A symplectic manifold $W$ with contact type boundary $M = \partial W$ induces a linearization of the contact homology of $M$ with corresponding linearized contact homology $HC(M)$. We establish a Gysin-type exact sequence in which the symplectic homology $SH(W)$ of $W$ maps to $HC(M)$, which in turn maps to $HC(M)$, by a map of degree -2, which then maps to $SH(W)$. Furthermore, we give a description of the degree -2 map in terms of rational holomorphic curves with constrained asymptotic markers, in the symplectization of $M$.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 15:07:59 GMT" }, { "version": "v2", "created": "Wed, 15 Oct 2008 09:36:44 GMT" } ]
2015-05-13T00:00:00
[ [ "Bourgeois", "Frédéric", "" ], [ "Oancea", "Alexandru", "" ] ]
0704.2170
Cornelius Krellner
C. Krellner, N.S. Kini, E.M. Bruning, K. Koch, H. Rosner, M. Nicklas, M. Baenitz, C. Geibel (Max Planck Institute for Chemical Physics of Solids, Dresden, Germany)
CeRuPO: A rare example of a Ferromagnetic Kondo lattice
accepted in Phys. Rev. B, high quality figures: http://www.cpfs.mpg.de/~krellner/
Phys. Rev. B 76, 104418 (2007)
10.1103/PhysRevB.76.104418
null
cond-mat.str-el
null
We have determined the physical ground state properties of the compounds CeRuPO and CeOsPO by means of magnetic susceptibility chi(T), specific heat C(T), electrical resistivity rho(T), and thermopower S(T) measurements. chi(T) reveals a trivalent 4f1 cerium state in both compounds. For CeRuPO a pronounced decrease of rho(T) below 50K indicates the onset of coherent Kondo scattering which is confirmed by enhanced S(T). The temperature and magnetic field dependence of chi(T) and C(T) evidence ferromagnetic (FM) order at TC=15K. Thus, CeRuPO seems to be one of the rare example of a FM Kondo lattice. In contrast, CeOsPO shows antiferromagnetic order at TN=4.4K despite only minor changes in lattice parameters and electronic configuration. Additional 31P NMR results support these scenarios. LSDA+U calculations evidence a quasi two dimensional electronic band structure, reflecting a strong covalent bonding within the CeO and RuP layers and a weak ionic like bonding between the layers.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 15:00:27 GMT" }, { "version": "v2", "created": "Fri, 10 Aug 2007 14:12:41 GMT" } ]
2007-09-24T00:00:00
[ [ "Krellner", "C.", "", "Max Planck Institute for Chemical Physics of Solids,\n Dresden, Germany" ], [ "Kini", "N. S.", "", "Max Planck Institute for Chemical Physics of Solids,\n Dresden, Germany" ], [ "Bruning", "E. M.", "", "Max Planck Institute for Chemical Physics of Solids,\n Dresden, Germany" ], [ "Koch", "K.", "", "Max Planck Institute for Chemical Physics of Solids,\n Dresden, Germany" ], [ "Rosner", "H.", "", "Max Planck Institute for Chemical Physics of Solids,\n Dresden, Germany" ], [ "Nicklas", "M.", "", "Max Planck Institute for Chemical Physics of Solids,\n Dresden, Germany" ], [ "Baenitz", "M.", "", "Max Planck Institute for Chemical Physics of Solids,\n Dresden, Germany" ], [ "Geibel", "C.", "", "Max Planck Institute for Chemical Physics of Solids,\n Dresden, Germany" ] ]
0704.2171
Samuela Pasquali
S. Pasquali, A.C. Maggs
Fluctuation-induced interactions between dielectrics in general geometries
null
null
10.1063/1.2949508
null
cond-mat.stat-mech cond-mat.soft physics.comp-ph quant-ph
null
We study thermal Casimir and quantum non-retarded Lifshitz interactions between dielectrics in general geometries. We map the calculation of the classical partition function onto a determinant which we discretize and evaluate with the help of Cholesky factorization. The quantum partition function is treated by path integral quantization of a set of interacting dipoles and reduces to a product of determinants. We compare the approximations of pairwise additivity and proximity force with our numerical methods. We propose a ``factorization approximation'' which gives rather good numerical results in the geometries that we study.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 15:05:27 GMT" }, { "version": "v2", "created": "Fri, 5 Oct 2007 17:05:15 GMT" } ]
2009-11-13T00:00:00
[ [ "Pasquali", "S.", "" ], [ "Maggs", "A. C.", "" ] ]
0704.2172
Wang Qing
Ying Zhang, Shun-Zhi Wang, Feng-Jun Ge, Qing Wang
Electroweak Chiral Lagrangian for Left-right Symmetric Models
null
Phys.Lett.B653:259-266,2007
10.1016/j.physletb.2007.07.054
null
hep-ph
null
The complete list of electroweak chiral Lagrangian up to order of p4 for left-right symmetric models with a neutral light higgs is provided. The connection of these operators to left and right gauge boson mixings and masses is made and their contribution to conventional generalized electroweak chiral Lagrangian with a neutral light higgs included in is estimated.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 15:33:38 GMT" } ]
2008-11-26T00:00:00
[ [ "Zhang", "Ying", "" ], [ "Wang", "Shun-Zhi", "" ], [ "Ge", "Feng-Jun", "" ], [ "Wang", "Qing", "" ] ]
0704.2173
Erez Ribak
V. Albanis, E. N. Ribak, Y. Carmon
Speckle reduction in ocular wave-front sensing
Submitted December 28, 2006
null
null
null
physics.optics physics.med-ph
null
An acousto-optic cell was used to reduce the speckle noise that reduces the quality of Hartmann-Shack and other wave-front sensors measuring ocular aberrations. In the method presented here, a laser beam traverses an acousto-optic cell, interacting with standing acoustic waves. Speckle reduction takes place as the incoming beam is diffractively spread across the cornea. The increased size and the wider angular spread of the incoming beam average out the speckles, producing a more uniform response of the wave-front sensor.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 15:11:47 GMT" } ]
2007-05-23T00:00:00
[ [ "Albanis", "V.", "" ], [ "Ribak", "E. N.", "" ], [ "Carmon", "Y.", "" ] ]
0704.2174
Sabine Moehler
S. Moehler
Good News for MOS, MXU & Co. - The New Spectroscopic Pipeline for the FORSes
6 pages, 6 Postscript figures, uses svmult.cls (included), to appear in the proceedings of the 2007 ESO Instrument Calibration Workshop
null
10.1007/978-3-540-76963-7_13
null
astro-ph
null
Since October 1, 2006, spectroscopic data from the two FORS instruments have been reduced with a new pipeline, which is based on a bottom-up calibration approach. I give a short description of the pipeline and discuss first experiences with automatic data reduction using this software, which has significantly increased the percentage of processed data for both instruments. I will also describe possible new options for Quality Control.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 15:37:02 GMT" } ]
2015-05-13T00:00:00
[ [ "Moehler", "S.", "" ] ]
0704.2175
Marc-Antoine Miville-Desch\^enes
M.-A. Miville-Deschenes (IAS, CITA), G. Lagache (IAS), F. Boulanger (IAS) and J.-L. Puget (IAS)
Statistical properties of dust far-infrared emission
13 pages, 13 figures. Accepted for publication in A&A
null
10.1051/0004-6361:20066962
null
astro-ph
null
The description of the statistical properties of dust emission gives important constraints on the physics of the interstellar medium but it is also a useful way to estimate the contamination of diffuse interstellar emission in the cases where it is considered a nuisance. The main goals of this analysis of the power spectrum and non-Gaussian properties of 100 micron dust emission are 1) to estimate the power spectrum of interstellar matter density in three dimensions, 2) to review and extend previous estimates of the cirrus noise due to dust emission and 3) to produce simulated dust emission maps that reproduce the observed statistical properties. The main results are the following. 1) The cirrus noise level as a function of brightness has been previously overestimated. It is found to be proportional to <I> instead of <I>^1.5, where <I> is the local average brightness at 100 micron. This scaling is in accordance with the fact that the brightness fluctuation level observed at a given angular scale on the sky is the sum of fluctuations of increasing amplitude with distance on the line of sight. 2) The spectral index of dust emission at scales between 5 arcmin and 12.5 degrees is <gamma>=-2.9 on average but shows significant variations over the sky. Bright regions have systematically steeper power spectra than diffuse regions. 3) The skewness and kurtosis of brightness fluctuations is high, indicative of strong non-Gaussianity. 4) Based on our characterization of the 100 micron power spectrum we provide a prescription of the cirrus confusion noise as a function of wavelength and scale. 5) Finally we present a method based on a modification of Gaussian random fields to produce simulations of dust maps which reproduce the power spectrum and non-Gaussian properties of interstellar dust emission.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 15:16:02 GMT" } ]
2009-11-13T00:00:00
[ [ "Miville-Deschenes", "M. -A.", "", "IAS, CITA" ], [ "Lagache", "G.", "", "IAS" ], [ "Boulanger", "F.", "", "IAS" ], [ "Puget", "J. -L.", "", "IAS" ] ]
0704.2176
Mahir S. Hussein
L. F. Canto, R. Donangelo and M. S. Hussein
Theoretical treatments of fusion processes in collisions of weakly bound nuclei
8 pages, 3 figures. Invited talk (LFC) at the IX International Conference on Nucleus-Nucleus Collisions, Rio de Janeiro, August 28- September 1, 2006. Nuclear Physics A, in press
Nucl.Phys.A787:243-250,2007
10.1016/j.nuclphysa.2006.12.039
null
nucl-th
null
We review the theoretical methods to evaluate fusion cross sections in collisions of weakly bound nuclei. We piont out that in such collisions the coupling to the breakup channel leads to the appearance of different fusion processes. The extentsion of the coupled-channel method to coupling with the continuum is the most successful treatment for these collisions. However, evaluating separate cross section for each fusion process remains a very hard task.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 15:19:28 GMT" } ]
2008-11-26T00:00:00
[ [ "Canto", "L. F.", "" ], [ "Donangelo", "R.", "" ], [ "Hussein", "M. S.", "" ] ]
0704.2177
Abhishek Rawat Mr.
A. Rawat (1 and 2), A. K. Kembhavi (2), F. Hammer (1), H. Flores (1), S. Barway (2) ((1) GEPI Observatoire de Paris Meudon France, (2) Inter University Center for Astronomy and Astrophysics IUCAA, Pune India)
Unravelling the morphologies of Luminous Compact Galaxies using the HST/ACS GOODS survey
Accepted for publication in A&A. 24 Pages, 10 figures. Fits files of sample galaxies available at http://www.iucaa.ernet.in/~rawat/lcg_1.html
null
10.1051/0004-6361:20065737
null
astro-ph
null
(Abridged) Luminous Compact Galaxies (LCGs) (M_B < -20, R_{1/2} < 4.5kpc and EW_{0}(OII) >15\AA) constitute one of the most rapidly evolving galaxy populations over the last ~8 Gyr history of the universe. Due to their inherently compact sizes, any detailed quantitative analysis of their morphologies has proved to be difficult in the past. In this work we use the high angular resolution imaging data, from the HST/ACS GOODS survey, to study the quantitative morphology of a complete sample of LCGs in the redshift range 0.5 < z < 1.2. We have derived structural parameters for a representative sample of 39 LCGs selected from the GOODS-S field, using full 2-dimensional surface brightness profile fitting of the galaxy images in each of the four filters available. B-z color maps are used as an aid in the morphological classification. We then use the rest frame B band bulge flux fraction (B/T) to determine the morphological class of the galaxies. Mergers were essentially identified visually by the presence of multiple maxima of comparable intensity in the rest frame B band images, aided by the color maps to distinguish them from HII regions. We derive the following morphological mix for our sample of intermediate redshift LCGs: Mergers: ~36%, Disk dominated: ~22%, S0: ~20%, Early types: ~7%, Irr/tadpole: ~15%. We establish that our sample LCGs are intermediate mass objects with a median stellar mass of Log(M/M_{\odot})=10.32. We also derive dust enshrouded SFR values ranging from a few to ~65 $M_{\odot}$/year using Spitzer 24$\mu m$ data. We estimate a factor ~11 fall in the comoving number density of blue LCGs from redshifts 0.5 < z < 1.2 to the current epoch. We finally discuss the evolutionary scenario of these LCGs which might give us some clues regarding their descendants in the local universe.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 14:59:16 GMT" } ]
2009-11-13T00:00:00
[ [ "Rawat", "A.", "", "1 and 2" ], [ "Kembhavi", "A. K.", "" ], [ "Hammer", "F.", "" ], [ "Flores", "H.", "" ], [ "Barway", "S.", "" ] ]
0704.2178
Andreas von Kienlin
Andreas von Kienlin, Gerald J. Fishman, Michael S. Briggs, Gary L. Godfrey and Helmut Steinle
High-Energy Calibration of a BGO detector of the GLAST Burst Monitor
2 pages, 1 figure; to appear in the Proc. of the First Int. GLAST Symp. (Stanford, Feb. 5-8, 2007), eds. S.Ritz, P.F.Michelson, and C.Meegan, AIP Conf. Proc
AIP Conf.Proc.921:576-577,2007
10.1063/1.2757459
null
astro-ph
null
The understanding of the instrumental response of the GLAST Burst Monitor BGO detectors at energies above the energy range which is accessible by common laboratory radiation sources (< 4.43 MeV), is important, especially for the later cross-calibration with the LAT response in the overlap region between ~ 20 MeV to 30 MeV. In November 2006 the high-energy calibration of the GBM-BGO spare detector was performed at the small Van-de-Graaff accelerator at SLAC. High-energy gamma-rays from excited 8Be* (14.6 MeV and 17.5 MeV) and 16O* (6.1 MeV) were generated through (p,gamma)-reactions by irradiating a LiF-target. For the calibration at lower energies radioactive sources were used. The results, including spectra, the energy/channel-relation and the dependence of energy resolution are presented.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 15:40:40 GMT" } ]
2009-06-23T00:00:00
[ [ "von Kienlin", "Andreas", "" ], [ "Fishman", "Gerald J.", "" ], [ "Briggs", "Michael S.", "" ], [ "Godfrey", "Gary L.", "" ], [ "Steinle", "Helmut", "" ] ]
0704.2179
David Neufeld
David A. Neufeld (JHU), David J. Hollenbach (NASA-Ames), Michael J. Kaufman (SJSU), Ronald L. Snell (UMass), Gary J. Melnick (CfA), Edwin A. Bergin (UMich), and Paule Sonnentrucker (JHU)
Spitzer spectral line mapping of supernova remnants: I. Basic data and principal component analysis
43 pages, including 21 figures. Accepted for publication in ApJ
Astrophys.J.664:890-908,2007
10.1086/518857
null
astro-ph
null
We report the results of spectroscopic mapping observations carried out toward small (1 x 1 arcmin) regions within the supernova remnants W44, W28, IC443, and 3C391 using the Infrared Spectrograph of the Spitzer Space Telescope. These observations, covering the 5.2 - 37 micron spectral region, have led to the detection of a total of 15 fine structure transitions of Ne+, Ne++, Si+, P+, S, S++, Cl+, Fe+, and Fe++; the S(0) - S(7) pure rotational lines of molecular hydrogen; and the R(3) and R(4) transitions of hydrogen deuteride. In addition to these 25 spectral lines, the 6.2, 7.7, 8.6, 11.3 and 12.6 micron PAH emission bands were also observed. Most of the detected line transitions have proven strong enough to map in several sources, providing a comprehensive picture of the relative distribution of the various line emissions observable in the Spitzer/IRS bandpass. A principal component analysis of the spectral line maps reveals that the observed emission lines fall into five distinct groups, each of which may exhibit a distinct spatial distribution: (1) lines of S and H2 (J > 2); (2) the H2 S(0) line; (3) lines of ions with appearance potentials less than 13.6 eV; (4) lines of ions with appearance potentials greater than 13.6 eV, not including S++; (5) lines of S++. Lines of group (1) likely originate in molecular material subject to a slow, nondissociative shock that is driven by the overpressure within the supernova remnant, and lines in groups (3) - (5) are associated primarily with dissociative shock fronts with a range of (larger) shock velocities. The H2 S(0) line shows a low-density diffuse emission component, and - in some sources - a shock-excited component.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 19:26:29 GMT" } ]
2009-06-23T00:00:00
[ [ "Neufeld", "David A.", "", "JHU" ], [ "Hollenbach", "David J.", "", "NASA-Ames" ], [ "Kaufman", "Michael J.", "", "SJSU" ], [ "Snell", "Ronald L.", "", "UMass" ], [ "Melnick", "Gary J.", "", "CfA" ], [ "Bergin", "Edwin A.", "", "UMich" ], [ "Sonnentrucker", "Paule", "", "JHU" ] ]
0704.2180
Guenter Plunien
A.I. Mikhailov, A.V. Nefiodov, G. Plunien
Single photoeffect on helium-like ions in the non-relativistic region
to be published in Physics Letters A
Phys. Lett. A 368 (2007) 391
10.1016/j.physleta.2007.04.027
null
physics.atom-ph
null
We present a generalization of the pioneering results obtained for single K-shell photoionization of H-like ions by M. Stobbe [Ann. Phys. 7 (1930) 661] to the case of the helium isoelectronic sequence. The total cross section of the process is calculated, taking into account the correlation corrections to first order of the perturbation theory with respect to the electron-electron interaction. Predictions are made for the entire non-relativistic energy domain. The phenomenon of dynamical suppression of correlation effects in the ionization cross section is discussed.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 15:33:00 GMT" } ]
2007-09-18T00:00:00
[ [ "Mikhailov", "A. I.", "" ], [ "Nefiodov", "A. V.", "" ], [ "Plunien", "G.", "" ] ]
0704.2181
Javier Almeida
J. Almeida, M.A. Martin-Delgado, G. Sierra
DMRG study of the Bond Alternating \textbf{S}=1/2 Heisenberg ladder with Ferro-Antiferromagnetic couplings
Version 4. 8 pages, 15 figures (12 figures in document)
Phys. Rev. B 76, 184428 (2007)
10.1103/PhysRevB.76.184428
null
cond-mat.str-el
null
We obtain the phase diagram in the parameter space $(J'/J, \gamma)$ and an accurate estimate of the critical line separating the different phases. We show several measuments of the magnetization, dimerization, nearest neighbours correlation, and density of energy in the different zones of the phase diagram, as well as a measurement of the string order parameter proposed as the non vanishing phase order parameter characterizing Haldane phases. All these results will be compared in the limit $J'/J\gg 1$ with the behaviour of the $\textbf{S}=1$ Bond Alternated Heisenberg Chain (BAHC). The analysis of our data supports the existence of a dimer phase separated by a critical line from a Haldane one, which has exactly the same nature as the Haldane phase in the $\textbf{S}=1$ BAHC.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 15:33:29 GMT" } ]
2009-11-13T00:00:00
[ [ "Almeida", "J.", "" ], [ "Martin-Delgado", "M. A.", "" ], [ "Sierra", "G.", "" ] ]
0704.2182
Umberto Maio Mr
U. Maio, K. Dolag, B. Ciardi, L. Tornatore
Metal and molecule cooling in simulations of structure formation
9 pages, plus appendices. Revised version. MNRAS accepted
null
10.1111/j.1365-2966.2007.12016.x
null
astro-ph
null
Cooling is the main process leading to the condensation of gas in the dark matter potential wells and consequently to star and structure formation. In a metal-free environment, the main available coolants are H, He, H$_2$ and HD; once the gas is enriched with metals, these also become important in defining the cooling properties of the gas. We discuss the implementation in Gadget-2 of molecular and metal cooling at temperatures lower that $\rm10^4 K$, following the time dependent properties of the gas and pollution from stellar evolution. We have checked the validity of our scheme comparing the results of some test runs with previous calculations of cosmic abundance evolution and structure formation, finding excellent agreement. We have also investigated the relevance of molecule and metal cooling in some specific cases, finding that inclusion of HD cooling results in a higher clumping factor of the gas at high redshifts, while metal cooling at low temperatures can have a significant impact on the formation and evolution of cold objects.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 16:07:03 GMT" }, { "version": "v2", "created": "Tue, 22 May 2007 18:16:02 GMT" }, { "version": "v3", "created": "Wed, 23 May 2007 09:33:10 GMT" } ]
2009-11-13T00:00:00
[ [ "Maio", "U.", "" ], [ "Dolag", "K.", "" ], [ "Ciardi", "B.", "" ], [ "Tornatore", "L.", "" ] ]
0704.2183
Michel Dekking
F.M. Dekking, L. van Driel and A. Fey
Stability in random Boolean cellular automata on the integer lattice
16 pages, 4 figures
Journal of Cellular Automata 5, (2010), 333-351
null
null
math.PR math.DS
null
We consider random boolean cellular automata on the integer lattice, i.e., the cells are identified with the integers from 1 to $N$. The behaviour of the automaton is mainly determined by the support of the random variable that selects one of the sixteen possible Boolean rules, independently for each cell. A cell is said to stabilize if it will not change its state anymore after some time. We classify the random boolean automata according to the positivity of their probability of stabilization. Here is an example of a consequence of our results: if the support contains at least 5 rules, then asymptotically as $N$ tends to infinity the probability of stabilization is positive, whereas there exist random boolean cellular automata with 4 rules in their support for which this probability tends to 0.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 15:37:32 GMT" }, { "version": "v2", "created": "Wed, 18 Apr 2007 14:15:35 GMT" }, { "version": "v3", "created": "Thu, 7 Feb 2008 10:42:47 GMT" } ]
2011-01-07T00:00:00
[ [ "Dekking", "F. M.", "" ], [ "van Driel", "L.", "" ], [ "Fey", "A.", "" ] ]
0704.2184
Andreas von Kienlin
Andreas von Kienlin, Elisabetta Bissaldi, Giselher G. Lichti, Helmut Steinle, Michael Krumrey, Martin Gerlach, Gerald J. Fishman, Charles Meegan, Narayana Bhat, Michael S. Briggs, Roland Diehl, Valerie Connaughton, Jochen Greiner, R. Marc Kippen, Chryssa Kouveliotou, William Paciesas, Robert Preece, and Colleen Wilson-Hodge
Calibration of the GLAST Burst Monitor detectors
2 pages, 1 figure; to appear in the Proc. of the First Int. GLAST Symp. (Stanford, Feb. 5-8, 2007), eds. S.Ritz, P.F.Michelson, and C.Meegan, AIP Conf. Proc
AIP Conf.Proc.921:578-579,2007
10.1063/1.2757460
null
astro-ph
null
The GLAST Burst Monitor (GBM) will augment the capabilities of GLAST for the detection of cosmic gamma-ray bursts by extending the energy range (20 MeV to > 300 GeV) of the Large Area Telescope (LAT) towards lower energies by 2 BGO-detectors (150 keV to 30 MeV) and 12 NaI(Tl) detectors (10 keV to 1 MeV). The physical detector response of the GBM instrument for GRBs is determined with the help of Monte Carlo simulations, which are supported and verified by on-ground calibration measurements, performed extensively with the individual detectors at the MPE in 2005. All flight and spare detectors were irradiated with calibrated radioactive sources in the laboratory (from 14 keV to 4.43 MeV). The energy/channel-relations, the dependences of energy resolution and effective areas on the energy and the angular responses were measured. Due to the low number of emission lines of radioactive sources below 100 keV, calibration measurements in the energy range from 10 keV to 60 keV were performed with the X-ray radiometry working group of the Physikalisch-Technische Bundesanstalt (PTB) at the BESSY synchrotron radiation facility, Berlin.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 15:46:00 GMT" } ]
2009-06-23T00:00:00
[ [ "von Kienlin", "Andreas", "" ], [ "Bissaldi", "Elisabetta", "" ], [ "Lichti", "Giselher G.", "" ], [ "Steinle", "Helmut", "" ], [ "Krumrey", "Michael", "" ], [ "Gerlach", "Martin", "" ], [ "Fishman", "Gerald J.", "" ], [ "Meegan", "Charles", "" ], [ "Bhat", "Narayana", "" ], [ "Briggs", "Michael S.", "" ], [ "Diehl", "Roland", "" ], [ "Connaughton", "Valerie", "" ], [ "Greiner", "Jochen", "" ], [ "Kippen", "R. Marc", "" ], [ "Kouveliotou", "Chryssa", "" ], [ "Paciesas", "William", "" ], [ "Preece", "Robert", "" ], [ "Wilson-Hodge", "Colleen", "" ] ]
0704.2185
Igor Anikin
I. V. Anikin, O. V. Teryaev
Dispersion relations and subtractions in hard exclusive processes
4 pages, journal version
Phys.Rev.D76:056007,2007
10.1103/PhysRevD.76.056007
null
hep-ph
null
We study analytical properties of the hard exclusive processes amplitudes. We found that QCD factorization for deeply virtual Compton scattering and hard exclusive vector meson production results in the subtracted dispersion relation with the subtraction constant determined by the Polyakov-Weiss $D$-term. The relation of this constant to the fixed pole contribution found by Brodsky, Close and Gunion and defined by parton distributions is proved, while its manifestation is spoiled by the small $x$ divergence. The continuation to the real photons limit is considered and the numerical correspondence between lattice simulations of $D$-term and low energy Thomson amplitude is found.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 15:47:24 GMT" }, { "version": "v2", "created": "Tue, 24 Apr 2007 14:14:38 GMT" }, { "version": "v3", "created": "Thu, 27 Sep 2007 11:15:46 GMT" } ]
2008-11-26T00:00:00
[ [ "Anikin", "I. V.", "" ], [ "Teryaev", "O. V.", "" ] ]
0704.2186
Umberto Maio Mr
U. Maio, K. Dolag, B. Ciardi, L. Tornatore
Metal and molecule cooling in simulations of structure formation
null
Mon.Not.Roy.Astron.Soc.379:963-973,2007
10.1111/j.1365-2966.2007.12016.x
null
astro-ph
null
This submission has been withdrawn by arXiv administrators because it is a duplicate of 0704.2182.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 15:48:45 GMT" } ]
2009-06-23T00:00:00
[ [ "Maio", "U.", "" ], [ "Dolag", "K.", "" ], [ "Ciardi", "B.", "" ], [ "Tornatore", "L.", "" ] ]
0704.2187
Michele Maris
Michele Maris, Giovanni Carraro, M. Gabriela Parisi
Light curves and colours of the faint Uranian irregular satellites Sycorax, Prospero, Stephano, Setebos and Trinculo
Submitted to A&A 13 Dec 2006, Accepted 17 Apr 2007. 18 pages, 8 colours figures BW printable, 6 tables. LaTeX 2.09, with packages: natbib, graphicx, longtable, aa4babbage included in the submission file (tar gzipped of 349 KBytes)
null
10.1051/0004-6361:20066927
null
astro-ph
null
After the work of Gladman et al. (1998), it is now assessed that many irregular satellites are orbiting around Uranus. Despite many studies have been performed in past years, very few is know for the light-curves of these objects and inconsistencies are present between colours derived by different authors. This situation motivated our effort to improve both the knowledge of colours and light curves. We present and discuss time series observations of Sycorax, Prospero, Stephano, Setebos and Trinculo, five faint irregular satellites of Uranus, carried out at VLT, ESO Paranal (Chile) in the nights between 29 and 30 July, 2005 and 25 and 30 November, 2005. We derive light curves for Sycorax and Prospero and colours for all of these these bodies. For Sycorax we obtain colours B-V =0.839 +/- 0.014, V-R = 0.531 +/- 0.005 and a light curve which is suggestive of a periodical variation with period about 3.6 hours and amplitude about 0.067 +/- 0.004 mag. The periods and colours we derive for Sycorax are in agreement with our previous determination in 1999 using NTT. We derive also a light-curve for Prospero which suggests an amplitude of about 0.2 mag and a periodicity of about 4 hours. However, the sparseness of our data, prevents a more precise characterization of the light-curves, and we can not determine wether they are one-peaked or two-peaked. Hence, these periods and amplitudes have to be considered preliminary estimates. As for Setebos, Stephano and Trinculo the present data do not allow to derive any unambiguous periodicity, despite Setebos displays a significant variability with amplitude about as large as that of Prospero. Colours for Prospero, Setebos, Stephano and Trinculo are in marginal agreement with the literature.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 16:48:36 GMT" } ]
2009-11-13T00:00:00
[ [ "Maris", "Michele", "" ], [ "Carraro", "Giovanni", "" ], [ "Parisi", "M. Gabriela", "" ] ]
0704.2188
A. Mourachkine
A. Mourachkine
Route to Room-Temperature Superconductivity from a Practical Point of View
Chapter in a book "Recent Developments in Superconductivity Research" ed. by B. Martins (Nova Science, New York, 2006) ISBN 1600214622, 35 pages including 8 figures
null
null
null
cond-mat.supr-con cond-mat.mtrl-sci
null
To synthesize a new superconductor which has a critical temperature, Tc, exceeding the room temperature, one needs to know what chemical components to start with. This chapter presents analysis of experimental data which allow one to draw a conclusion about components and the structure of a potential room-temperature superconductor. The two essential components of a room temperature superconductor are large organic molecules (polymers, tissues) and atoms/molecules which are magnetic in the intercalated state. This conclusion is fully based on experimental facts known today, and does not require any assumptions about the mechanism of room-temperature superconductivity. This, however, does not mean that to synthesize a room-temperature superconductor is an easy task.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 16:06:19 GMT" } ]
2007-05-23T00:00:00
[ [ "Mourachkine", "A.", "" ] ]
0704.2189
Silvia Piranomonte Miss
F. Fiore, D. Guetta, S. Piranomonte, V. D'Elia, L.A. Antonelli
Selection effects shaping the Gamma Ray Burst redshift distributions
9 pages, back to A&A after referee report
null
10.1051/0004-6361:20077157
null
astro-ph
null
Long Gamma Ray Bursts hold the promise of probing star-formation and metal enrichment up to very high redshifts. The present GRB samples with redshift determination are largely incomplete and therefore a careful analysis of selection effects is mandatory before any conclusion can be drawn from the observed GRB redshift distribution. We study and compare three well defined samples of long GRBs detected by Swift, HETE2 and BeppoSAX. We find that Swift GRBs are slighly fainter and harder than BeppoSAX and HETE2 GRBs, as expected due to the higher energy range in which Swift GRBs are detected and localized, compared to BeppoSAX and HETE2. Gas and dust obscuration plays a role in shaping the GRB samples and the present samples of GRBs with redshift. We argue that the majority of the bright Swift GRBs without redshift might actually be z<~2 events therefore the present Swift GRB sample with redshift is biased against low-z GRBs. On the other hand, the detection of bright UV rest-frame afterglows from high-z GRBs, and even from those with large X-ray obscuration, implies a dust amount lower than in nearby GRBs,and/or a different dust composition. If this is the case, the Swift sample of GRBs with redshifts is probably a fair sample of the real high-z GRB population. The absence of high-z GRBs in the BeppoSAX and HETE2 samples of GRBs with redshifts is probably due to the fact at the time of BeppoSAX and HETE2 follow-up faint afterglows of high redshift GRBs will have weaken below the spectroscopic capabilities of even 10m class telescopes. The redshift distribution of a subsample of Swift GRBs with distributions of peak-fluxes, X-ray obscuration and optical magnitude at a fixed observing time similar to those of the BeppoSAX and HETE2 samples, is roughly consistent with BeppoSAX+HETE2 redshift distribution.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 16:09:07 GMT" }, { "version": "v2", "created": "Wed, 18 Apr 2007 13:09:14 GMT" } ]
2009-11-13T00:00:00
[ [ "Fiore", "F.", "" ], [ "Guetta", "D.", "" ], [ "Piranomonte", "S.", "" ], [ "D'Elia", "V.", "" ], [ "Antonelli", "L. A.", "" ] ]
0704.2190
Guenter Plunien
L. Labzowsky, G. Schedrin, D. Solovyev, G. Plunien
Theoretical study of the accuracy limits for the optical resonance frequency measurements
to be published in Physical Review Letters
null
10.1103/PhysRevLett.98.203003
null
physics.atom-ph
null
The principal limits for the accuracy of the resonance frequency measurements set by the asymmetry of the natural resonance line shape are studied and applied to the recent accurate frequency measurements in the two-photon 1s-2s resonance and in the one-photon 1s-2p resonance in hydrogen atom. This limit for 1s-2s resonance is found to be $\sim 10^{-5}$ Hz compared to the accuracy achieved in experiment $\pm 46$ Hz. In case of deuterium atom the limit is essentially larger: $10^{-2}$ Hz. For 1s-2p resonance the accuracy limit is 0.17 MHz while the uncertainty of the recent frequency measurement is about 6 MHz.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 16:14:36 GMT" } ]
2009-11-13T00:00:00
[ [ "Labzowsky", "L.", "" ], [ "Schedrin", "G.", "" ], [ "Solovyev", "D.", "" ], [ "Plunien", "G.", "" ] ]
0704.2191
Bo Deng
Bo Deng
Mismatch Repair Error Implies Chargaff's Second Parity Rule
null
null
null
null
q-bio.GN
null
Chargaff's second parity rule holds empirically for most types of DNA that along single strands of DNA the base contents are equal for complimentary bases, A = T, G = C. A Markov chain model is constructed to track the evolution of any single base position along single strands of genomes whose organisms are equipped with replication mismatch repair. Under the key assumptions that mismatch error rates primarily depend the number of hydrogen bonds of nucleotides and that the mismatch repairing process itself makes strand recognition error, the model shows that the steady state probabilities for any base position to take on one of the 4 nucleotide bases are equal for complimentary bases. As a result, Chargaff's second parity rule is the manifestation of the Law of Large Number acting on the steady state probabilities. More importantly, because the model pinpoints mismatch repair as a basis of the rule, it is suitable for experimental verification.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 16:15:37 GMT" }, { "version": "v2", "created": "Thu, 20 Sep 2007 15:46:34 GMT" } ]
2007-09-20T00:00:00
[ [ "Deng", "Bo", "" ] ]
0704.2192
Dr. Michael T. Wolff
Michael T. Wolff, Peter A. Becker, Kenneth D. Wolfram
Comptonization and the Spectra of Accretion-Powered X-Ray Pulsars
6 Pages, 2 Figures, To appear in "The Multicoloured Landscape of Compact Objects and their Explosive Progenitors" (Cefalu, Sicily, June 2006). Eds. L. Burderi et al. (New York: AIP)
AIPConf.Proc.924:496-501,2007
10.1063/1.2774900
null
astro-ph
null
Accretion-powered X-ray pulsars are among the most luminous X-ray sources in the Galaxy. However, despite decades of theoretical and observational work since their discovery, no satisfactory model for the formation of the observed X-ray spectra has emerged. In this paper, we report on a self-consistent calculation of the spectrum emerging from a pulsar accretion column that includes an explicit treatment of the bulk and thermal Comptonization occurring in the radiation-dominated shocks that form in the accretion flows. Using a rigorous eigenfunction expansion method, we obtain a closed-form expression for the Green's function describing the upscattering of monochromatic radiation injected into the column. The Green's function is convolved with bremsstrahlung, cyclotron, and blackbody source terms to calculate the emergent photon spectrum. We show that energization of photons in the shock naturally produces an X-ray spectrum with a relatively flat continuum and a high-energy exponential cutoff. Finally, we demonstrate that our model yields good agreement with the spectra of the bright pulsar Her X-1 and the low luminosity pulsar X Per.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 18:45:26 GMT" } ]
2008-11-26T00:00:00
[ [ "Wolff", "Michael T.", "" ], [ "Becker", "Peter A.", "" ], [ "Wolfram", "Kenneth D.", "" ] ]
0704.2193
Dorin Poenaru
D. N. Poenaru, R. A. Gherghescu, A. V. Solov'yov, W. Greiner
Liquid Drop Stability of a Superdeformed Prolate Semi-Spheroidal Atomic Cluster
5 pages, 3 figurex, revtex4
Europhysics Letters (EPL), 79 (2007) 63001
10.1209/0295-5075/79/63001
null
physics.atm-clus
null
Analytical relationships for the surface and curvature energies of oblate and prolate semi-spheroidal atomic clusters have been obtained. By modifying the cluster shape from a spheroid to a semi-spheroid the most stable shape was changed from a sphere to a superdeformed prolate semi-spheroid (including the flat surface of the end cap). Potential energy surfaces vs. deformation and the number of atoms, N, illustrate this property independent of N.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 16:43:10 GMT" }, { "version": "v2", "created": "Mon, 17 Sep 2007 15:22:57 GMT" }, { "version": "v3", "created": "Tue, 18 Sep 2007 12:05:40 GMT" } ]
2007-09-18T00:00:00
[ [ "Poenaru", "D. N.", "" ], [ "Gherghescu", "R. A.", "" ], [ "Solov'yov", "A. V.", "" ], [ "Greiner", "W.", "" ] ]
0704.2194
David Roberts
Yves Pomeau and David C. Roberts
Casimir Friction I: Friction of a vacuum on a spinning dielectric
To appear in Modern Encyclopedia of Mathematical Physics (MEMPhys); campanion article to cond-mat/0503757; v2 - minor editorial changes
null
null
null
quant-ph
null
We introduce the concept of Casimir friction, i.e. friction due to quantum fluctuations. In this first article we describe the calculation of a constant torque, arising from the scattering of quantum fluctuations, on a dielectric rotating in an electromagnetic vacuum.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 16:43:30 GMT" }, { "version": "v2", "created": "Wed, 9 Apr 2008 19:19:34 GMT" } ]
2008-04-09T00:00:00
[ [ "Pomeau", "Yves", "" ], [ "Roberts", "David C.", "" ] ]
0704.2195
C. W. Engelbracht
C. W. Engelbracht, M. Blaylock, K. Y. L. Su, J. Rho, G. H. Rieke, J. Muzerolle, D. L. Padgett, D. C. Hines, K. D. Gordon, D. Fadda, A. Noriega-Crespo, D. M. Kelly, W. B. Latter, J. L. Hinz, K. A. Misselt, J. E. Morrison, J. A. Stansberry, D. L. Shupe, S. Stolovy, Wm. A. Wheaton, E. T. Young, G. Neugebauer, S. Wachter, P. G. P\'erez-Gonz\'alez, D. T. Frayer, and F. R. Marleau
Absolute Calibration and Characterization of the Multiband Imaging Photometer for Spitzer. I. The Stellar Calibrator Sample and the 24 micron Calibration
33 pages, 10 figures, to be published in PASP
Publ.Astron.Soc.Pac.119:994-1018,2007
10.1086/521881
null
astro-ph
null
We present the stellar calibrator sample and the conversion from instrumental to physical units for the 24 micron channel of the Multiband Imaging Photometer for Spitzer (MIPS). The primary calibrators are A stars, and the calibration factor based on those stars is 4.54*10^{-2} MJy sr^{-1} (DN/s)^{-1}, with a nominal uncertainty of 2%. We discuss the data-reduction procedures required to attain this accuracy; without these procdures, the calibration factor obtained using the automated pipeline at the Spitzer Science Center is 1.6% +/- 0.6% lower. We extend this work to predict 24 micron flux densities for a sample of 238 stars which covers a larger range of flux densities and spectral types. We present a total of 348 measurements of 141 stars at 24 micron. This sample covers a factor of ~460 in 24 micron flux density, from 8.6 mJy up to 4.0 Jy. We show that the calibration is linear over that range with respect to target flux and background level. The calibration is based on observations made using 3-second exposures; a preliminary analysis shows that the calibration factor may be 1% and 2% lower for 10- and 30-second exposures, respectively. We also demonstrate that the calibration is very stable: over the course of the mission, repeated measurements of our routine calibrator, HD 159330, show a root-mean-square scatter of only 0.4%. Finally, we show that the point spread function (PSF) is well measured and allows us to calibrate extended sources accurately; Infrared Astronomy Satellite (IRAS) and MIPS measurements of a sample of nearby galaxies are identical within the uncertainties.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 16:48:33 GMT" } ]
2016-08-14T00:00:00
[ [ "Engelbracht", "C. W.", "" ], [ "Blaylock", "M.", "" ], [ "Su", "K. Y. L.", "" ], [ "Rho", "J.", "" ], [ "Rieke", "G. H.", "" ], [ "Muzerolle", "J.", "" ], [ "Padgett", "D. L.", "" ], [ "Hines", "D. C.", "" ], [ "Gordon", "K. D.", "" ], [ "Fadda", "D.", "" ], [ "Noriega-Crespo", "A.", "" ], [ "Kelly", "D. M.", "" ], [ "Latter", "W. B.", "" ], [ "Hinz", "J. L.", "" ], [ "Misselt", "K. A.", "" ], [ "Morrison", "J. E.", "" ], [ "Stansberry", "J. A.", "" ], [ "Shupe", "D. L.", "" ], [ "Stolovy", "S.", "" ], [ "Wheaton", "Wm. A.", "" ], [ "Young", "E. T.", "" ], [ "Neugebauer", "G.", "" ], [ "Wachter", "S.", "" ], [ "Pérez-González", "P. G.", "" ], [ "Frayer", "D. T.", "" ], [ "Marleau", "F. R.", "" ] ]
0704.2196
Karl D. Gordon
Karl D. Gordon, Charles W. Engelbracht, Dario Fadda, John Stansberry, Stefanie Wachter, Dave T. Frayer, George Rieke, Alberto Noriega-Crespo, William B. Latter, Erick Young, Gerry Neugebauer, Zoltan Balog, Herve Dole, Eiichi Egami, Dean Hines, Doug Kelly, Francine Marleau, Karl Misselt, Jane Morrison, Pablo Perez-Gonzalez, Jeonghee Rho, and Wm. A. Wheaton
Absolute Calibration and Characterization of the Multiband Imaging Photometer for Spitzer. II. 70 micron Imaging
19 pages, PASP, in press
Publ.Astron.Soc.Pac.119:1019-1037,2007
10.1086/522675
null
astro-ph
null
The absolute calibration and characterization of the Multiband Imaging Photometer for Spitzer (MIPS) 70 micron coarse- and fine-scale imaging modes are presented based on over 2.5 years of observations. Accurate photometry (especially for faint sources) requires two simple processing steps beyond the standard data reduction to remove long-term detector transients. Point spread function (PSF) fitting photometry is found to give more accurate flux densities than aperture photometry. Based on the PSF fitting photometry, the calibration factor shows no strong trend with flux density, background, spectral type, exposure time, or time since anneals. The coarse-scale calibration sample includes observations of stars with flux densities from 22 mJy to 17 Jy, on backgrounds from 4 to 26 MJy sr^-1, and with spectral types from B to M. The coarse-scale calibration is 702 +/- 35 MJy sr^-1 MIPS70^-1 (5% uncertainty) and is based on measurements of 66 stars. The instrumental units of the MIPS 70 micron coarse- and fine-scale imaging modes are called MIPS70 and MIPS70F, respectively. The photometric repeatability is calculated to be 4.5% from two stars measured during every MIPS campaign and includes variations on all time scales probed. The preliminary fine-scale calibration factor is 2894 +/- 294 MJy sr^-1 MIPS70F^-1 (10% uncertainty) based on 10 stars. The uncertainty in the coarse- and fine-scale calibration factors are dominated by the 4.5% photometric repeatability and the small sample size, respectively. The 5-sigma, 500 s sensitivity of the coarse-scale observations is 6-8 mJy. This work shows that the MIPS 70 micron array produces accurate, well calibrated photometry and validates the MIPS 70 micron operating strategy, especially the use of frequent stimulator flashes to track the changing responsivities of the Ge:Ga detectors.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 16:49:12 GMT" } ]
2010-01-07T00:00:00
[ [ "Gordon", "Karl D.", "" ], [ "Engelbracht", "Charles W.", "" ], [ "Fadda", "Dario", "" ], [ "Stansberry", "John", "" ], [ "Wachter", "Stefanie", "" ], [ "Frayer", "Dave T.", "" ], [ "Rieke", "George", "" ], [ "Noriega-Crespo", "Alberto", "" ], [ "Latter", "William B.", "" ], [ "Young", "Erick", "" ], [ "Neugebauer", "Gerry", "" ], [ "Balog", "Zoltan", "" ], [ "Dole", "Herve", "" ], [ "Egami", "Eiichi", "" ], [ "Hines", "Dean", "" ], [ "Kelly", "Doug", "" ], [ "Marleau", "Francine", "" ], [ "Misselt", "Karl", "" ], [ "Morrison", "Jane", "" ], [ "Perez-Gonzalez", "Pablo", "" ], [ "Rho", "Jeonghee", "" ], [ "Wheaton", "Wm. A.", "" ] ]
0704.2197
Guenter Plunien
V. Sharipov, L. Labzowsky, G. Plunien
Excited states of the helium-antihydrogen system
null
Phys. Rev. Lett. 98 (2007) 103001
10.1103/PhysRevLett.98.103001
null
physics.atom-ph
null
Potential energy curves for excited leptonic states of the helium-antihydrogen system are calculated within Ritz' variational approach. An explicitly correlated ansatz for the leptonic wave function is employed describing accurately the motion of the leptons (two electrons and positron) in the field of the helium nucleus and of the antiproton with arbitrary orbital angular momentum projection $\Lambda$ onto the internuclear axis. Results for $\Lambda$=0, 1 and 30 are presented. For quasibound states with large values of $\Lambda$ and rotational quantum numbers $J>\Lambda$ no annihilation and rearrangement decay channels occur, i. e. they are metastable.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 16:51:41 GMT" } ]
2015-05-13T00:00:00
[ [ "Sharipov", "V.", "" ], [ "Labzowsky", "L.", "" ], [ "Plunien", "G.", "" ] ]
0704.2198
James Cline
James M. Cline
Braneworld Cosmology
14 pages, 2 figures, invited review talk given at "From Strings to LHC," International Center, Dona Paula, Goa, India, 2-10 Jan. 2007
PoSstringsLHC:011,2006
null
McGill-07-527
hep-th astro-ph hep-ph
null
A brief review of the field of braneworld cosmology, from its inception with the large extra dimension scenario, to aspects of cosmology in warped extra dimensions, including the RS-I and RS-II models, braneworld inflation, the Goldberger-Wise mechanism, mirage cosmology, the radion-induced phase transition in RS-I, possible gravity wave signals, and the DGP model.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 16:53:24 GMT" } ]
2008-11-26T00:00:00
[ [ "Cline", "James M.", "" ] ]
0704.2199
Michael Todd
Henk Bruin, Mike Todd
Equilibrium states for interval maps: the potential $-t\log |Df|$
null
Ann. Sci. Ecole Norm. Sup. (4) 42 (2009) 559-600.
null
null
math.DS
null
Let $f:I \to I$ be a $C^2$ multimodal interval map satisfying polynomial growth of the derivatives along critical orbits. We prove the existence and uniqueness of equilibrium states for the potential $\phi_t:x\mapsto -t\log|Df(x)|$ for $t$ close to 1, and also that the pressure function $t \mapsto P(\phi_t)$ is analytic on an appropriate interval near $t = 1$.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 17:00:46 GMT" }, { "version": "v2", "created": "Fri, 7 Dec 2007 19:51:53 GMT" }, { "version": "v3", "created": "Mon, 18 Feb 2008 16:50:47 GMT" }, { "version": "v4", "created": "Tue, 19 Feb 2008 16:40:29 GMT" } ]
2009-11-17T00:00:00
[ [ "Bruin", "Henk", "" ], [ "Todd", "Mike", "" ] ]
0704.2200
Stefan Bornholdt
Maria I. Davidich, Stefan Bornholdt
Boolean network model predicts cell cycle sequence of fission yeast
10 pages, 3 figures
null
10.1371/journal.pone.0001672
null
q-bio.MN
null
A Boolean network model of the cell-cycle regulatory network of fission yeast (Schizosaccharomyces Pombe) is constructed solely on the basis of the known biochemical interaction topology. Simulating the model in the computer, faithfully reproduces the known sequence of regulatory activity patterns along the cell cycle of the living cell. Contrary to existing differential equation models, no parameters enter the model except the structure of the regulatory circuitry. The dynamical properties of the model indicate that the biological dynamical sequence is robustly implemented in the regulatory network, with the biological stationary state G1 corresponding to the dominant attractor in state space, and with the biological regulatory sequence being a strongly attractive trajectory. Comparing the fission yeast cell-cycle model to a similar model of the corresponding network in S. cerevisiae, a remarkable difference in circuitry, as well as dynamics is observed. While the latter operates in a strongly damped mode, driven by external excitation, the S. pombe network represents an auto-excited system with external damping.
[ { "version": "v1", "created": "Tue, 17 Apr 2007 18:47:31 GMT" } ]
2015-05-13T00:00:00
[ [ "Davidich", "Maria I.", "" ], [ "Bornholdt", "Stefan", "" ] ]