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May 2009 arXiv papers — page 30

Showing 2,9013,000 of 5,084 papers

  1. Fernando Izaurieta, Paul Minning, Alfredo Pérez, Eduardo Rodríguez

    Chern-Simons models for gravity are interesting because they provide with a truly gauge-invariant action principle in the fiber-bundle sense. So far, their main drawback has largely been the perceived remoteness from standard General Relativity, based on the presence of higher powers of the curvature in the Lagrangian (except, remarkably, for three-dimension

  2. Tetsuji Kimura, Shun'ya Mizoguchi

    We show that there exist two 27 and one 27bar of E6, net one chiral supermultiplet as zero modes localized on the intersecting 5-branes in the E8 x E8 heterotic string theory. A heterotic background is constructed by the standard embedding in the smeared solution, and the Dirac equation is solved explicitly on this background. It provides, after a compactifi

  3. Desika Narayanan, Thomas J. Cox, Christopher Hayward, Joshua D. Younger

    We present a model for the CO molecular line emission from high redshift Submillimeter Galaxies (SMGs). By combining hydrodynamic simulations of gas rich galaxy mergers with the polychromatic radiative transfer code, Sunrise, and the 3D non-LTE molecular line radiative transfer code, Turtlebeach, we show that if SMGs are typically a transient phase of major

  4. Dušan Kereš, Lars Hernquist

    We use one of the highest resolution cosmological SPH simulations to date to demonstrate that cold gaseous clouds form around Milky Way size galaxies. We further explore mechanisms responsible for their formation and show that a large fraction of clouds originate as a consequence of late-time filamentary "cold mode" accretion. Here, filaments that ar

  5. Max Tegmark

    Everett's Many-Worlds Interpretation of quantum mechanics is discussed in the context of other physics disputes and other proposed kinds of parallel universes. We find that only a small fraction of the usual objections to Everett's theory are specific to quantum mechanics, and that all of the most controversial issues crop up also in settings that ha

  6. Joseph Silk, Colin Norman

    A general treatment of disk star formation is developed from a dissipative multi-phase model, with the dominant dissipation due to cloud collisions. The Schmidt-Kennicutt law emerges naturally for star-forming disks and starbursts. We predict that there should be an inverse correlation between Tully-Fisher law and Schmidt-Kennicutt law residuals. The model i

  7. Ivano Eligio Castelli, Rosario Capozza, Andrea Vanossi, Giuseppe E. Santoro

    In the framework of Langevin dynamics, we demonstrate clear evidence of the peculiar quantized sliding state, previously found in a simple 1D boundary lubricated model [Phys. Rev. Lett. 97, 056101 (2006)], for a substantially less idealized 2D description of a confined multi-layer solid lubricant under shear. This dynamical state, marked by a nontrivial ``qu

  8. Leo Radzihovsky, Quan Zhang

    We explore liquid crystal order in a cell with a "dirty" substrate imposing a random surface pinning. Modeling such systems by a random-field xy-model with surface heterogeneity, we find that orientational order in the three-dimensional system is marginally unstable to such surface pinning. We compute the Larkin length scale, and the corresponding su

  9. Andreas Enge, Pierrick Gaudry, Emmanuel Thomé

    We present an algorithm for solving the discrete logarithm problem in Jacobians of families of plane curves whose degrees in $X$ and $Y$ are low with respect to their genera. The finite base fields $\FF_q$ are arbitrary, but their sizes should not grow too fast compared to the genus. For such families, the group structure and discrete logarithms can be compu

  10. Florentina Bunea, Adrian Barbu

    Dimension reduction and variable selection are performed routinely in case-control studies, but the literature on the theoretical aspects of the resulting estimates is scarce. We bring our contribution to this literature by studying estimators obtained via L1 penalized likelihood optimization. We show that the optimizers of the L1 penalized retrospective lik

  11. Liangpan Li, Jian Shen

    Let $A$ be a finite set of positive real numbers. We present a sum-division estimate: |A+A|^2|A/A|\geq\frac{|A|^4}{4}.

  12. Steven Kleiman, Ragni Piene, Ilya Tyomkin

    Given a smooth family F/Y of geometrically irreducible surfaces, we study sequences of arbitrarily near T-points of F/Y; they generalize the traditional sequences of infinitely near points of a single smooth surface. We distinguish a special sort of these new sequences, the strict sequences. To each strict sequence, we associate an ordered unweighted Enrique

  13. Clément Mouhot, Cédric Villani

    Dans cette note nous présentons les principaux résultats du récent travail hal-00376547/arXiv:0904.2760, où le phénomène d'amortissement Landau est pour la première fois établi dans un contexte non linéaire. ----- In this note we present the main results from the recent work hal-00376547 / arXiv:0904.2760, which for the first time establish Landau dampin

  14. Clément Mouhot, Cédric Villani

    In this note we present the main results from the recent work hal-00376547/arXiv:0904.2760, which for the first time establish Landau damping in a nonlinear context.

  15. M. Eshaghi Gordji, N. Ghobadipour

    In this paper, we establish the Mazur--Ulam theorem in the fuzzy strictly convex real normed spaces.

  16. Milton Jara, Tomasz Komorowski

    In this paper we consider an additive functional of an observable $V(x)$ of a Markov jump process. We assume that the law of the expected jump time $t(x)$ under the invariant probability measure $π$ of the skeleton chain belongs to the domain of attraction of a subordinator. Then, the scaled limit of the functional is a Mittag-Leffler proces, provided that $

  17. Thomas Vojta

    We consider the behavior of the Grüneisen parameter, the ratio between thermal expansion and specific heat, at pressure-tuned infinite-randomness quantum-critical points and in the associated quantum Griffiths phases. We find that the Grüneisen parameter diverges as $\ln(T_0/T)$ with vanishing temperature $T$ in the quantum Griffiths phases. At the infinite-

  18. F. Yusef-Zadeh, J. W. Hewitt, R. G. Arendt, B. Whitney

    The central kpc of the Milky Way might be expected to differ significantly from the rest of the Galaxy with regard to gas dynamics and the formation of YSOs. We probe this possibility with mid-infrared observations obtained with IRAC and MIPS on Spitzer and with MSX. We use color-color diagrams and SED fits to explore the nature of YSO candidates (including

  19. Loïc Chaumont, Gerónimo Uribe Bravo

    A Markovian bridge is a probability measure taken from a disintegration of the law of an initial part of the path of a Markov process given its terminal value. As such, Markovian bridges admit a natural parameterization in terms of the state space of the process. In the context of Feller processes with continuous transition densities, we construct by weak co

  20. Tengfei Luo, John R. Lloyd

    Non-equilibrium molecular dynamics (NEMD) simulations were performed on Au-SAM (self-assembly monolayer)-Au junctions to study the thermal energy transport across the junctions. Thermal conductance of the Au-SAM interfaces was calculated. Temperature effects, simulated external pressure effects, SAM molecule coverage effects and Au-SAM bond strength effects

  21. Finn Larsen, Ross O'Connell

    We use the flux attractor equations to study IIB supergravity compactifications with ISD fluxes. We show that the attractor equations determine not just the values of moduli fields, but also the masses of those moduli and the gravitino. We then show that the flux attractor equations can be recast in terms of derivatives of a single generating function. We al

  22. Hyun-chul Lee, Guy Worthey, Aaron Dotter

    We present simple stellar population (SSP) models with scaled-solar and alpha-element enhanced abundances. The SSP models are based on the Dartmouth Stellar Evolution Database, our library of synthetic stellar spectra, and a detailed systematic variation of horizontal-branch (HB) morphology with age and metallicity. In order to test the relative importance o

  23. A. Abulencia etal

    We report a measurement of the ratio of branching fractions of the decays B+ ->JPsi pi+ and B+ -> Jpsi K+ using the CDF II detector at the Fermilab Tevatron Collider. The signal from the Cabbibo-suppressed B+->JPsi pi+ decay is separated from B+->JPsi K+ using the invariant mass distribution and the kinematics differences of the hadron track in the two decay

  24. Timur Delahaye, Pierre Brun, Fiorenza Donato, Nicolao Fornengo

    Recent PAMELA and ATIC data seem to indicate an excess in positron cosmic rays above approximately 10 GeV which might be due to galactic Dark Matter particle annihilation. However the background of this signal suffers many uncertainties that make our task difficult in constraining Dark Matter or any other astrophysical explanation for these recent surprising

  25. Hirosi Ooguri, Chang-Soon Park

    We construct M-theory supergravity solutions with the non-relativistic Schrodinger symmetry starting from the warped AdS_5 metric with N=1 supersymmetry. We impose the condition that the lightlike direction is compact by making it a non-trivial U(1) bundle over the compact space. Sufficient conditions for such solutions are analyzed. The solutions have two s

  26. D. W. Boukhvalov, M. I. Katsnelson

    Simulation of chemical activity of corrugated graphene within density functional theory predicts an enhancement of its chemical activity if the ratio of height of the corrugation (ripple) to its radius is larger than 0.07. Further growth of the curvature of the ripples results in appearance of midgap states which leads to an additional strong increase of che

  27. Yvonne Choquet-Bruhat, Piotr T. Chrusciel, Jose M. Martin-Garcia

    We prove that the area of cross-sections of light-cones, in space-times satisfying suitable energy conditions, is smaller than or equal to that of the corresponding cross-sections in Minkowski, or de Sitter, or anti-de Sitter space-time. The equality holds if and only if the metric coincides with the corresponding model in the domain of dependence of the lig

  28. R. Cowsik, B. Burch

    The recent observations of the positron fraction in cosmic rays by PAMELA indicate that the fraction of positrons to the total electronic component in cosmic rays initially decreases in the energy region 1-10 GeV and increases thereafter. In this paper, we show that it is natural to expect such an increase of the positron fraction within the context of cosmi

  29. Joshua S. Bloom, J. Xavier Prochaska, William Lee, J. Jesús González

    We are proposing to conduct a multicolor, synoptic infrared (IR) imaging survey of the Northern sky with a new, dedicated 6.5-meter telescope at San Pedro Mártir (SPM) Observatory. This initiative is being developed in partnership with astronomy institutions in Mexico and the University of California. The 4-year, dedicated survey, planned to begin in 2017, w

  30. Mathieu Rubin

    It is widely believed that searching for a light Higgs boson (with a mass around 120 GeV) in the WH and ZH channels, where H decays into $b\bar{b}$, will be very challenging at the LHC. These proceedings describe how this channel can be recovered as a promising search channel at high $p_t$ by using a subjet analysis procedure.

  31. Anne Sickles

    One unexpected recent result from heavy-ion collisions is the large suppression and elliptic flow of electrons from heavy flavor decay. Further measurements of properties of electrons from heavy flavor decay are crucial to understanding the origin of this suppression and its implications for the properties of the hot matter produced at RHIC. Two particle cor

  32. Laszlo Erdos, Jose A. Ramirez, Benjamin Schlein, Horng-Tzer Yau

    We consider $N\times N$ Hermitian random matrices with independent identically distributed entries (Wigner matrices). We assume that the distribution of the entries have a Gaussian component with variance $N^{-3/4+β}$ for some positive $β>0$. We prove that the local eigenvalue statistics follows the universal Dyson sine kernel.

  33. Christina Pöltl, Clive Emary, Tobias Brandes

    We study transport through a triple quantum dot in a triangular geometry with applied bias such that both singly- and doubly- charged states participate. We describe the formation of electronic dark states -- coherent superpositions that block current flow -- in the system, and focus on the formation of a two-electron dark state. We discuss the conditions un

  34. T. E. Wall, S. Armitage, J. J. Hudson, B. E. Sauer

    An alternating gradient electric guide provides a way to transport a wide variety of polar molecules, including those in high-field seeking states. We investigate the motion of polar molecules in such a guide by measuring the transmission of CaF molecules in their high-field seeking ground state, with the guide operating at a variety of switching frequencies

  35. J. Piekarewicz, M. Centelles, X. Roca-Maza, X. Viñas

    The Garvey-Kelson (GK) relations are powerful algebraic expressions connecting the masses of neighboring atomic nuclei and derived under reasonable physical assumptions. In this contribution we show that these relations are even more general than originally assumed as their validity is conditioned by the smoothness of the underlying nuclear mass function and

  36. Luis J. Alias, Paolo Piccione

    We use bifurcation theory to show the existence of infinite sequences isometric embeddings of tori with constant mean curvature (CMC) in Euclidean spheres that are not isometrically congruent to the CMC Clifford tori, and accumulating at some CMC Clifford torus.

  37. Anjan S. Joshipura, Werner Rodejohann

    The scaling hypothesis postulates proportionality of two columns of the Majorana neutrino mass matrix in the flavor basis. This Ansatz was shown to lead to an inverted hierarchy and U_{e3} = 0. We discuss theoretical and phenomenological properties of this hypothesis. We show that (i) the neutrino mass matrix with scaling follows as a consequence of a genera

  38. S. Akbari, E. Ghorbani, M. R. Oboudi

    We conjecture that the sum of the square roots of the Laplacian eigenvalues of a graph does not exceed the sum of the square roots of its signless Laplacian eigenvalues.

  39. Jenia Jitsev, Christoph von der Malsburg

    Growing neuropsychological and neurophysiological evidence suggests that the visual cortex uses parts-based representations to encode, store and retrieve relevant objects. In such a scheme, objects are represented as a set of spatially distributed local features, or parts, arranged in stereotypical fashion. To encode the local appearance and to represent the

  40. Shengjun Wu, Uffe V. Poulsen, Klaus Mølmer

    We consider the classical correlations that two observers can extract by measurements on a bipartite quantum state, and we discuss how they are related to the quantum mutual information of the state. We show with several examples how complementarity gives rise to a gap between the quantum and the classical correlations, and we relate our quantitative finding

  41. Nicolau C. Saldanha

    A smooth curve $γ: [0,1] \to S^2$ is locally convex if its geodesic curvature is positive at every point. J. A. Little showed that the space of all locally positive curves $γ$ with $γ(0) = γ(1) = e_1$ and $γ'(0) = γ'(1) = e_2$ has three connected components $L_{-1,c}$, $L_{+1}$, $L_{-1,n}$. The space $L_{-1,c}$ is known to be contractible but the top

  42. Nicolau C. Saldanha

    A smooth curve $γ: [0,1] \to S^2$ is locally convex if its geodesic curvature is positive at every point. J. A. Little showed that the space of all locally positive curves $γ$ with $γ(0) = γ(1) = e_1$ and $γ'(0) = γ'(1) = e_2$ has three connected components $L_{-1,c}$, $L_{+1}$, $L_{-1,n}$. The space $L_{-1,c}$ is known to be contractible but the top

  43. Shoichi Fujimori, Francisco J. Lopez

    The geometry and topology of complete nonorientable maximal surfaces with lightlike singularities in the Lorentz-Minkowski 3-space are studied. Some topological congruence formulae for surfaces of this kind are obtained. As a consequence, some existence and uniqueness results for maximal Moebius strips and maximal Klein bottles with one end are proved.

  44. H. Heiselberg

    Many-body effects on superfluidity and transition temperatures are calculated for optical lattices and uniform systems with ultracold multi-component Fermi gases. The induced interactions depend sensitively on the interactions between the multi-components and their densities. The s- and d-wave pairing gaps and critical temperatures are calculated for optical

  45. Benjamin Nill, Andreas Paffenholz

    In this note we report on examples of 7- and 8-dimensional toric Fano manifolds that are not symmetric and still admit a Kaehler-Einstein metric. This answers a question first posed by V.V. Batyrev and E. Selivanova. The examples were found in the classification of toric Fano manifolds up to dimension 8 obtained by M. Oebro. We also discuss related open ques

  46. Andrew G. Semenov, Andrei D. Zaikin

    We investigate the effect of electron-electron interactions on Aharonov-Bohm (AB) current oscillations in nanorings formed by a chain of metallic quantum dots. We demonstrate that electron-electron interactions cause electron dephasing thereby suppressing the amplitude of AB oscillations at all temperatures down to T=0. The crossover between thermal and quan

  47. Keisuke Hatada, Kuniko Hayakawa, Fabrizio Palumbo

    In a recent study of the magnetic properties of rare-earth systems the two extreme situations have been considered in which the crystalline electrostatic field is large or small with respect to the spin-orbit interaction. In the first case the orbitals of localized electrons are firmly coupled to the lattice so that while an applied magnetic field rotates th

  48. A. A. Zheltukhin, M. Trzetrzelewski

    The geometric approach to study the dynamics of U(1)-invariant membranes is developed. The approach reveals an important role of the Abel nonlinear differential equation of the first type with variable coefficients depending on time and one of the membrane extendedness parameters. The general solution of the Abel equation is constructed. Exact solutions of t

  49. Joseph J. Hilling, Anthony Sudbery

    It is shown that the geometric measure of entanglement of a pure multipartite state satisfies a polynomial equation, generalising the characteristic equation of the matrix of coefficients of a bipartite state. The equation is solved for a class of three-qubit states.

  50. A. I. Zenchuk

    We represent an algorithm allowing one to construct new classes of partially integrable multidimensional nonlinear partial differential equations (PDEs) starting with the special type of solutions to the (1+1)-dimensional hierarchy of nonlinear PDEs linearizable by the matrix Hopf-Cole substitution (the Bürgers hierarchy). We derive examples of four-dimensio

  51. Simen Adnoy Ellingsen, Iver Brevik, Kimball A. Milton

    We consider the Casimir energy in a geometry of an infinite magnetodielectric wedge closed by a circularly cylindrical, perfectly conducting arc embedded in another magnetodielectric medium, under the condition that the speed of light be the same in both media. An expression for the Casimir energy corresponding to the arc is obtained and it is found that in

  52. G. Botelho, D. Pellegrino, P. Rueda

    The main goal of this note is to establish a connection between the cotype of the Banach space X and the parameters r for which every 2-homogeneous polynomial on X is r-dominated. Let cotX be the infimum of the cotypes assumed by X and (cotX)* be its conjugate. The main result of this note asserts that if cotX > 2, then for every 1<= r < (cotX)* there exists

  53. Junji Hisano, Kazunori Nakayama, Masaki J. S. Yang

    We study upward muon flux at neutrino detectors such as Super-Kamiokande resulting from high-energy neutrinos produced by the dark matter annihilation/decay at the Galactic center. In particular, we distinguish showering and non-showering muons as their energy loss processes inside the detector, and show that this information is useful for discriminating dar

  54. S. Y. Chang

    The radio frequency spectrum of the fermions in the unitary limit at finite temperatures is characterized by the sum rule relations. We consider a simple picture where the atoms are removed by radio frequency excitations from the strongly interacting states into a state of negligible interaction. We calculate the moments of the response function in the range

  55. Pasquale Calabrese, John Cardy, Erik Tonni

    We study the entanglement of two disjoint intervals in the conformal field theory of the Luttinger liquid (free compactified boson). Tr\rho_A^n for any integer n is calculated as the four-point function of a particular type of twist fields and the final result is expressed in a compact form in terms of the Riemann-Siegel theta functions. In the decompactific

  56. Andrea Macchi, Silvia Veghini, Francesco Pegoraro

    The dynamics of the acceleration of ultrathin foil targets by the radiation pressure of superintense, circularly polarized laser pulses is investigated by analytical modeling and particle-in-cell simulations. By addressing self-induced transparency and charge separation effects, it is shown that for &#34;optimal&#34; values of the foil thickness only a thin

  57. E. Lhuillier, I. Ribet-Mohamed, A. Nedelcu, V. Berger

    We report on the study of the electrical current flowing in weakly coupled superlattice (SL) structures under an applied electric field at very low temperature, i.e. in the tunneling regime. This low temperature transport is characterized by an extremely low tunneling probability between adjacent wells. Experimentally, I(V) curves at low temperature display

  58. Ricardo Gallego Torrome

    It is shown that the Lorentz force equation is equivalent to the auto-parallel condition $\,^L\nabla_{\dot{x}}\dot{x}=0$ of a linear connection $^L\nabla$ defined on a convenient pull-back vector bundle. By using a geometric averaging method, an associated {\it averaged Lorentz connection} $\langle\,^L\nabla\rangle$ and the corresponding auto-parallel equati

  59. Alexander Gorsky

    We discuss multiloop MHV amplitudes in the N=4 SYM theory in terms of effective gravity in the momentum space with IR regulator branes as degrees of freedom. Kinematical invariants of external particles yield the moduli spaces of complex or Kahler structures which are the playgrounds for the Kodaira-Spencer(KS) or Kahler type gravity. We suggest fermionic re

  60. Songbai Chen, Jiliang Jing

    Adopting the strong field limit approach, we studied the properties of strong field gravitational lensing in the deformed Hǒrava-Lifshitz black hole and obtained the angular position and magnification of the relativistic images. Supposing that the gravitational field of the supermassive central object of the galaxy described by this metric, we estimated the

  61. P. Barletta, C. Romero-Redondo, A. Kievsky, M. Viviani

    Application of the Hyperspherical Adiabatic expansion to describe three-body scattering states suffers the problem of a very slow convergence. Contrary to what happens for bound states, a huge number of hyperradial equations has to be solved, and even if done, the extraction of the scattering amplitude is problematic. In this paper we show how to obtain accu

  62. H. K. Dreiner, S. Grab, Daniel Koschade, M. Kramer

    We investigate the bounds on the mass of the lightest neutralino from rare meson decays within the MSSM with and without minimal flavor violation. We present explicit formulae for the two-body decays of mesons into light neutralinos and perform the first complete calculation of the loop-induced decays of kaons to pions and light neutralinos and B mesons to k

  63. Jerome Novak, Jean-Louis Cornou, Nicolas Vasset

    The wave equation for vectors and symmetric tensors in spherical coordinates is studied under the divergence-free constraint. We describe a numerical method, based on the spectral decomposition of vector/tensor components onto spherical harmonics, that allows for the evolution of only those scalar fields which correspond to the divergence-free degrees of fre

  64. Hing-Tong Cho, Kin-Wang Ng, I-Chin Wang

    We calculate quantum fluctuations of a free scalar field in the Schwarzschild-de Sitter space-time, adopting the planar coordinates that is pertinent to the presence of a black hole in an inflationary universe. In a perturbation approach, doing expansion in powers of a small black hole event horizon compared to the de Sitter cosmological horizon, we obtain t

  65. Wei-Bo Gao, Ping Xu, Xing-Can Yao, Otfried Gühne

    We experimentally demonstrate an optical controlled-NOT (CNOT) gate with arbitrary single inputs based on a 4-photon 6-qubit cluster state entangled both in polarization and spatial modes. We first generate the 6-qubit state, and then by performing single-qubit measurements the CNOT gate is applied to arbitrary single input qubits. To characterize the perfor

  66. Koichi Funakubo, Eibun Senaha

    The electroweak phase transition and the sphaleron decoupling condition in the MSSM are revisited taking the latest experimental data into account. The light Higgs boson scenario and the ordinary decoupling limit which are classified by the relative size between the CP-odd Higgs boson mass and Z boson mass are considered within the context of electroweak bar

  67. G. J. Conduit, B. D. Simons

    We investigate ferromagnetic ordering in an itinerant ultracold atomic Fermi gas with repulsive interactions and population imbalance. In a spatially uniform system, we show that at zero temperature the transition to the itinerant magnetic phase transforms from first to second order with increasing population imbalance. Drawing on these results, we elucidate

  68. Marianna Ridderstad, Jari Okkonen

    The orientations of 23 Giant&#39;s Churches, dating from 2500-2000 BCE, located in Ostrobothnia, Finland, have been measured. Many of them are found to have orientations to the risings and settings of the sun on the main solar dates of the year.

  69. Aharon Levy

    The energy dependence of cross sections is discussed as a way to learn about the dynamics of photon induced interactions at HERA. The question of determining the scale of exclusive electroproduction of vector mesons is addressed.

  70. J. Alanen, K. Kajantie, V. Suur-Uski

    The computation of the spatial string tension of finite temperature QCD is discussed in QCD and in a gravity+scalar model of gauge/gravity duality.

  71. Sergey A. Podoshvedov

    We propose a scheme for quantum key distribution (QKD) protocol with dual-rail displaced photon states. Displaced single photon states carry bit value of code which may be extracted while coherent states carry nothing and they only provide inconclusive outcome. Developed QKD protocol works with experimental attendant noise to observe presence of malicious Ev

  72. S. B. Igamov, Q. I. Tursunmahatov, R. Yarmukhamedov

    A new analysis of the modern precise measured astrophysical $S$ factors for the direct capture $^3He(α,γ)^7{\rm {Be}}$ reaction [B.S. Nara Singh {\it et al.}, Phys.Rev.Lett. {\bf 93}, 262503 (2004); D. Bemmerer {\it et al.}, Phys.Rev.Lett. {\bf 97}, 122502 (2006); F.Confortola {\it et al.}, Phys.Rev.C {\bf 75}, 065803 (2007), T.A.D.Brown {\it et al.}, Phys.R

  73. Ken&#39;ichiro Nakazato, Kazuhiro Oyamatsu, Shoichi Yamada

    Nuclear matter is considered to be inhomogeneous at subnuclear densities that are realized in supernova cores and neutron star crusts, and the structures of nuclear matter change from spheres to cylinders, slabs, cylindrical holes and spherical holes as the density increases. In this letter, we discuss other possible structures, that is, gyroid and double-di

  74. N. N. Achasov, G. N. Shestakov

    The light scalar mesons, discovered over forty years ago, became a challenge for the naive quark-antiquark model from the outset. At present the nontrivial nature of these states is no longer denied practically anybody. Two-photon physics has made a substantial contribution to understanding the nature of the light scalar mesons. Recently, it entered a new st

  75. E. Aldo Arroyo

    We evaluate the cubic interaction term in the action of open bosonic string field theory for Schnabl&#39;s solution written in terms of Bernoulli numbers. This computation provides us with a new evidence for the fact that the string field equation of motion is satisfied when it is contracted with the solution itself.

  76. Greta Panova

    We prove a formula for the number of permutations in $S_n$ such that their first $n-k$ entries are increasing and their longest increasing subsequence has length $n-k$. This formula first appeared as a consequence of character polynomial calculations in recent work of Adriano Garsia and Alain Goupil. We give two `elementary&#39; bijective proofs of this resu

  77. J. Ponce de Leon

    We study the effective spacetimes in lower dimensions that can be extracted from a multidimensional generalization of the Schwarzschild-Tangherlini spacetimes derived by Fadeev, Ivashchuk and Melnikov ({\it Phys. Lett,} {\bf A 161} (1991) 98). The higher-dimensional spacetime has $D = (4 + n + m)$ dimensions, where $n$ and $m$ are the number of &#34;internal

  78. Shunichiro Kittaka, Taketomo Nakamura, Hiroshi Yaguchi, Shingo Yonezawa

    We have clarified how the enhanced superconductivity, often referred to as the 3-K phase superconductivity, develops in the Sr2RuO4-Ru eutectic system. From the detailed ac and dc susceptibility measurements on well-characterized crystals, we revealed strongly anisotropic shielding, governed by the direction of the screening current dominated within the RuO2

  79. Gideon Amir, Omer Angel, Balint Virag

    We prove that every linear-activity automaton group is amenable. The proof is based on showing that a sufficiently symmetric random walk on a specially constructed degree 1 automaton group -- the mother group -- has asymptotic entropy 0. Our result answers an open question by Nekrashevich in the Kourovka notebook, and gives a partial answer to a question of

  80. Seiji Harikae, Tomoya Takiwaki, Kei Kotake

    We present our numerical results of two-dimensional magnetohydrodynamic (MHD) simulations of the collapse of rotating massive stars in light of the collapsar model of gamma-ray bursts (GRBs). Pushed by recent evolution calculations of GRB progenitors, we focus on lower angular momentum of the central core than the ones taken mostly in previous studies. By pe

  81. Takahiro Murashima, Takashi Taniguchi

    We have developed a simulation technique of multiscale Lagrangian fluid dynamics to tackle hierarchical problems relating to historical dependency of polymeric fluid. We investigate flow dynamics of dilute polymeric fluid by using the multiscale simulation approach incorporating Lagrangian particle fluid dynamics technique (the modified smoothed particle hyd

  82. Sho Matsumoto, Jonathan Novak

    In this paper, we study the relationship between polynomial integrals on the unitary group and the conjugacy class expansion of symmetric functions in Jucys-Murphy elements. Our main result is an explicit formula for the top coefficients in the class expansion of monomial symmetric functions in Jucys-Murphy elements, from which we recover the first order asy

  83. Halyun Jeong, Young-Han Kim

    This paper studies the question of how well a signal can be reprsented by a sparse linear combination of reference signals from an overcomplete dictionary. When the dictionary size is exponential in the dimension of signal, then the exact characterization of the optimal distortion is given as a function of the dictionary size exponent and the number of refer

  84. Maxim Eingorn, Alexander Zhuk

    In the case of one extra dimension, well known Newton&#39;s potential $ϕ(r_3)=-G_N m/r_3$ is generalized to compact and elegant formula $ϕ(r_3,ξ)=-(G_N m/r_3)\sinh(2πr_3/a)[\cosh(2πr_3/a)-\cos(2πξ/a)]^{-1}$ if four-dimensional space has topology $\mathbb{R}^3\times T$. Here, $r_3$ is magnitude of three-dimensional radius vector, $ξ$ is extra dimension and $a

  85. Joseph Najnudel, Bernard Roynette, Marc Yor

    In this monograph, we construct and study a sigma-finite measure on continuous functions from R_+ to R, strongly related to many probability measures obtained by penalisation of Brownian motion, i.e. as limits of probabilities which are absolutely continuous with respect to Wiener measure. This remarkable sigma-finite measure can be generalized in three othe

  86. Vladimir Novikov

    We classify generalised Camassa-Holm type equations which possess infinite hierarchies of higher symmetries. We show that the obtained equations can be treated as negative flows of integrable quasi-linear scalar evolution equations of orders 2, 3 and 5. We present the corresponding Lax representations or linearisation transformations for these equations. Som

  87. Nicolas G. Hadjiconstantinou, Gregg A. Radtke, Lowell L. Baker

    We present and discuss a variance-reduced stochastic particle method for simulating the relaxation-time model of the Boltzmann transport equation. The present paper focuses on the dilute gas case, although the method is expected to directly extend to all fields (carriers) for which the relaxation-time approximation is reasonable. The variance reduction, achi

  88. R. Vijay, J. D. Sau, Marvin L. Cohen, I. Siddiqi

    Josephson tunnel junctions are widely used as nonlinear elements in superconducting circuits such as low noise amplifiers and quantum bits. However, microscopic defects in the oxide tunnel barrier can produce low and high frequency noise which can potentially limit the coherence times and quality factors of resonant circuits. Weak link Josephson junctions ar

  89. J. R. Leonard, Y. Kuznetsova, Sen Yang, L. V. Butov

    Spin transport of indirect excitons in GaAs/AlGaAs coupled quantum wells was observed by measuring the spatially resolved circular polarization of exciton emission. Exciton spin transport over several microns originates from a long spin relaxation time and long lifetime of indirect excitons.

  90. Michael T. Goodrich, Michael J. Nelson, Jonathan Z. Sun

    We present a distributed data structure, which we call the rainbow skip graph. To our knowledge, this is the first peer-to-peer data structure that simultaneously achieves high fault tolerance, constant-sized nodes, and fast update and query times for ordered data. It is a non-trivial adaptation of the SkipNet/skip-graph structures of Harvey et al. and Aspne

  91. Florian Johann, Yongjun J. Ying, Tobias Jungk, Akos Hoffmann

    Given that a ferroelectric domain is generally a three dimensional entity, the determination of its area as well as its depth is mandatory for full characterization. Piezoresponse force microscopy (PFM) is known for its ability to map the lateral dimensions of ferroelectric domains with high accuracy. However, no depth profile information has been readily av

  92. D. Gallego, S. Hofferberth, T. Schumm, P. Krüger

    Optical dipole traps and atom chips are two very powerful tools for the quantum manipulation of neutral atoms. We demonstrate that both methods can be combined by creating an optical lattice potential on an atom chip. A red-detuned laser beam is retro-reflected using the atom chip surface as a high-quality mirror, generating a vertical array of purely optica

  93. Anna Kaminska, Pawel Pacholek

    Motivated by a recent discussion about the role of flat directions, a typical feature of supersymmetric models, in the process of particle production in the early universe a consistent model of inflation and preheating in supergravity with MSSM fields has been built. It is based on a model proposed by M. Kawasaki, M. Yamaguchi and T. Yanagida. In the inflati

  94. Ounsi El Daif, Emmanuel Drouard, Yeonsang Park, Alain Fave

    We report on very high enhancement of thin layer&#39;s absorption through band-engineering of a photonic crystal structure. We realized amorphous silicon (aSi) photonic crystals, where slow light modes improve absorption efficiency. We show through simulation that an increase of the absorption by a factor of 1.5 is expected for a film of aSi. The proposal is

  95. Debprakash Patnaik, Sean P. Ponce, Yong Cao, Naren Ramakrishnan

    Temporal data mining algorithms are becoming increasingly important in many application domains including computational neuroscience, especially the analysis of spike train data. While application scientists have been able to readily gather multi-neuronal datasets, analysis capabilities have lagged behind, due to both lack of powerful algorithms and inaccess

  96. Palle E. T. Jorgensen

    We study infinite weighted graphs with view to \textquotedblleft limits at infinity,\textquotedblright or boundaries at infinity. Examples of such weighted graphs arise in infinite (in practice, that means \textquotedblleft very\textquotedblright large) networks of resistors, or in statistical mechanics models for classical or quantum systems. But more gener

  97. C. Deluca

    Prompt photon production results by the CDF and D\OCollaborations in the Tevatron Run II at a center of mass energy of $\sqrt{s}$=1.96 TeV are presented. Cross sections for central isolated photons, photon+jet production and photons produced in association with a heavy flavor quark are reported. The measurements are compared to Next-to-Leading order perturba

  98. Yong Cao, Debprakash Patnaik, Sean Ponce, Jeremy Archuleta

    Computational neuroscience is being revolutionized with the advent of multi-electrode arrays that provide real-time, dynamic, perspectives into brain function. Mining event streams from these chips is critical to understanding the firing patterns of neurons and to gaining insight into the underlying cellular activity. We present a GPGPU solution to mining sp

  99. Takahiro Tsushima

    The Grothendieck-Ogg-Shafarevich formula is generalized to any dimensional scheme by Abbes-Kato-Saito. In this paper, we introduce two methods of localization of the characteristic classes for sheaves of rank 1 and compare them. As a corollary of this comparison, we obtain a refinement of a formula proved by Abbes-Saito without denominator for a smooth sheaf

  100. Matthew T. Calef

    Let $A$ be a compact set in $\Rp$ of Hausdorff dimension $d$. For $s\in(0,d)$, the Riesz $s$-equilibrium measure $μ^{s,A}$ is the unique Borel probability measure with support in $A$ that minimizes $$ \Is(μ):=\iint\Rk{x}{y}{s}dμ(y)dμ(x)$$ over all such probability measures. In this paper we show that if $A$ is a strictly self-similar $d$-fractal, then $μ^{s,