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January 2010 arXiv papers — page 53

Showing 5,2015,300 of 5,448 papers

  1. Rajkumar Kannan, Frederic Andres, Balakrishnan Ramadoss

    Recent advances in hardware sophistication related to graphics display, audio and video devices made available a large number of multimedia and hypermedia applications. These multimedia applications need to store and retrieve the different forms of media like text, hypertext, graphics, still images, animations, audio and video. Dance is one of the important

  2. A. M. Stewart, Lewis T. Chadderton, Brian R. Senior

    It is proposed that primary nucleation of amorphous microspherulites of hydrated silica in natural proto-precious-opal can be followed by a long range superlattice ordering process by means of electrostatic self-assembly. Necessary conditions in the thermodynamics are a high surface charge density on microspherulite surfaces, a long Debye length and an appro

  3. Michael R. Haas, Natalie M. Batalha, Steve T. Bryson, Douglas A. Caldwell

    Kepler's primary mission is a search for earth-size exoplanets in the habitable zone of late-type stars using the transit method. To effectively accomplish this mission, Kepler orbits the Sun and stares nearly continuously at one field-of-view which was carefully selected to provide an appropriate density of target stars. The data transmission rates, ope

  4. Amin Gholampour, Hsian-Hua Tseng

    We present a construction of Donaldson-Thomas invariants for three-dimensional projective Calabi-Yau Deligne-Mumford stacks. We also study the structure of these invariants for etale gerbes over such stacks.

  5. A. V. Latyshev, A. A. Yushkanov

    We construct a kinetic equation modeling the behavior of degenerate quantum Bose gases whose collision rate depends on the momentum of elementary excitations. We consider the case where the phonon component is the decisive factor in the elementary excitations. We analytically solve the half-space boundary value problem of the temperature jump at the boundary

  6. Ren Gui Zhu

    We use Green's function method to study the Heisenberg model of LaFeAsO with the striped antiferromagnetic collinear spin structure. In addition to the intra-layer spin couplings $J_{1a},J_{1b},J_2$ and the inter-layer coupling $J_c$, we further consider the contributions of the single-ion anisotropy $J_s$. The analytical expressions for the magnetic pha

  7. Gary Shambat, Yiyang Gong, Jesse Lu, Selcuk Yerci

    Optical fiber tapers are used to collect photoluminescence emission at ~1.5 um from photonic crystal cavities fabricated in erbium doped silicon nitride on silicon. Photoluminescence collection via fiber taper is enhanced 2.5 times relative to free space, with a total taper collection efficiency of 53%. By varying the fiber taper offset from the cavity, a br

  8. Hirotaka Sugawara

    Solution to the reduced matrix model of IKKT type is studied with non-zero fermion fields. A suggestion is made that our universe is made of rational numbers rather than being a continuum. To substantiate this proposal, the reduced Yang-Mills equation is written in the form of an elliptic curve. The normalization of the solution can be expressed in terms of

  9. Jixia Yuan, Wende Liu

    The principal filtration of the infinite-dimensional odd Contact Lie superalgebra over a field of characteristic $p>2$ is proved to be invariant under the automorphism group by investigating ad-nilpotent elements and determining certain invariants such as subalgebras generated by some ad-nilpotent elements. Then, it is proved that two automorphisms coincide

  10. Hidetsugu Sakaguchi, Boris A. Malomed

    We study ordinary solitons and gap solitons (GSs) in the effectively one-dimensional Gross-Pitaevskii equation, with a combination of linear and nonlinear lattice potentials. The main points of the analysis are effects of the (in)commensurability between the lattices, the development of analytical methods, viz., the variational approximation (VA) for narrow

  11. A. L. Carey, J. Phillips, I. F. Putnam, A. Rennie

    We construct a family of purely infinite $C^*$-algebras, $\mathcal{Q}^λ$ for $λ\in (0,1)$ that are classified by their $K$-groups. There is an action of the circle $\T$ with a unique ${\rm KMS}$ state $ψ$ on each $\mathcal{Q}^λ.$ For $λ=1/n,$ $\mathcal{Q}^{1/n}\cong O_n$, with its usual $\T$ action and ${\rm KMS}$ state. For $λ=p/q,$ rational in lowest terms

  12. Y. Jiao, F. H. Stillinger, S. Torquato

    Dense random packings of hard particles are useful models of granular media and are closely related to the structure of nonequilibrium low-temperature amorphous phases of matter. Most work has been done for random jammed packings of spheres, and it is only recently that corresponding packings of nonspherical particles (e.g., ellipsoids) have received attenti

  13. Javier Tordable

    Integer factorization is a very hard computational problem. Currently no efficient algorithm for integer factorization is publicly known. However, this is an important problem on which it relies the security of many real world cryptographic systems. I present an implementation of a fast factorization algorithm on MapReduce. MapReduce is a programming model f

  14. Jon M. Jenkins, William J. Borucki, David G. Koch, Geoffrey W. Marcy

    We report the discovery and the Rossiter-McLaughlin effect of Kepler-8b, a transiting planet identified by the NASA Kepler Mission. Kepler photometry and Keck-HIRES radial velocities yield the radius and mass of the planet around this F8IV subgiant host star. The planet has a radius RP = 1.419 RJ and a mass, MP = 0.60 MJ, yielding a density of 0.26 g cm^-3,

  15. Apisit Pakapongpun, Thomas Ward

    We study the behaviour of the dynamical zeta function and the orbit Dirichlet series for products of maps. The behaviour under products of the radius of convergence for the zeta function, and the abscissa of convergence for the orbit Dirichlet series, are discussed. The orbit Dirichlet series of the cartesian cube of a map with one orbit of each length is sh

  16. Hamed Dehghan, S. Ebrahim Safavi

    In this paper a new approach to image watermarking in wavelet domain is presented. The idea is to hide the watermark data in blocks of the block segmented image. Two schemes are presented based on this idea by embedding the watermark data in the low pass wavelet coefficients of each block. Due to low computational complexity of the proposed approach, this al

  17. Edward Liverts, Michael Mond, Vadim Urpin

    A linear stability analysis of ionized discs with a temperature gradient and an external axial magnetic field is presented. It is shown that both hydromagnetic and thermomagnetic effects can lead to the amplification of waves and make discs unstable. The conditions under which the instabilities grow are found and the characteristic growth rate is calculated.

  18. Nic Shannon, Karlo Penc, Yukitoshi Motome

    The classical bilinear-biquadratic nearest-neighbor Heisenberg antiferromagnet on the pyrochlore lattice does not exhibit conventional Neel-type magnetic order at any temperature or magnetic field. Instead spin correlations decay algebraically over length scales r ~ \sqrt{T}, behavior characteristic of a Coulomb phase arising from a strong local constraint.

  19. Luc Hillairet, Chris Judge

    We describe a method for comparing the real analytic eigenbranches of two families of quadratic forms that degenerate as t tends to zero. One of the families is assumed to be amenable to `separation of variables' and the other one not. With certain additional assumptions, we show that if the families are asymptotic at first order as t tends to 0, then th

  20. Alexei Moiseev, Igor Karachentsev, Serafim Kaisin

    We use integral-field and long-slit spectroscopy to study the bright extended nebulosity discovered in the isolated lenticular galaxy NGC 4460 during a recent H-alpha survey of nearby galaxies. An analysis of archival SDSS, GALEX, and HST images indicates that current star formation is entirely concentrated in the central kiloparsec of the galaxy disc. The o

  21. Huyen Pham

    We formulate and investigate a general stochastic control problem under a progressive enlargement of filtration. The global information is enlarged from a reference filtration and the knowledge of multiple random times together with associated marks when they occur. By working under a density hypothesis on the conditional joint distribution of the random tim

  22. Michael A. K. Gross, Ralph Y. Shuping

    SOFIA is a 2.5 meter airborne infrared telescope, mounted in a Boeing 747SP aircraft. Due to the large size of the telescope, only a few degrees of azimuth are available at the telescope bearing. This means the heading of the aircraft is fundamentally associated with the telescope's observation targets, and the ground track necessary to enable a given mi

  23. Robert Ralowski

    We show that for a $σ$-ideal $\ci$ with a Steinhaus property defined on Banach space, if two non-homeomorphic Banach with the same cardinality of the Hamel basis then there is a $\ci$ nonmeasurable subset as image by any isomorphism between of them. Our results generalize results from [2]

  24. John Campbell

    Bayesian methods since the time of Laplace have been understood by their practitioners as closely aligned to the scientific method. Indeed a recent champion of Bayesian methods, E. T. Jaynes, titled his textbook on the subject Probability Theory: the Logic of Science. Many philosophers of science including Karl Popper and Donald Campbell have interpreted the

  25. M. E. Cates, D. Marenduzzo, I. Pagonabarraga, J. Tailleur

    We present a generic mechanism by which reproducing microorganisms, with a diffusivity that depends on the local population density, can form stable patterns. It is known that a decrease of swimming speed with density can promote separation into bulk phases of two coexisting densities; this is opposed by the logistic law for birth and death which allows only

  26. Taekyun Kim, Y. H. Kim

    In this paper we give new identities involving q-Euler polynomials of higher order.

  27. Silvio M. Duarte Queiros

    In this manuscript we discuss the effectiveness of the Kozachenko-Leonenko entropy estimator when generalised to cope with entropic forms customarily applied to study systems evincing asymptotic scale invariance and dependence (either linear or non-linear type). We show that when the variables are independently and identically distributed the estimator is on

  28. Hanfeng Li

    For a countable amenable group Γand an element f in the integral group ring ZΓbeing invertible in the group von Neumann algebra of Γ, we show that the entropy of the shift action of Γon the Pontryagin dual of the quotient of ZΓby its left ideal generated by f is the logarithm of the Fuglede-Kadison determinant of f. For the proof, we establish an \ell^p-vers

  29. Sascha Orlik, Matthias Strauch

    Let G be a p-adic Lie group. This paper is about the Jordan-Hoelder series of locally analytic G-representations which are induced from locally algebraic representations of a parabolic subgroup.

  30. Deepak Ponvel Chermakani

    An important question arising from the Frobenius Coin Problem is to decide whether or not a given monetary sum S can be obtained from N coin denominations. We develop a new Generating Function G(x), where the coefficient of x^i is equal to the number of ways in which coins from the given denominations can be arranged as a stack whose total monetary worth is

  31. William F. Welsh, Jerome A. Orosz, Sara Seager, Jonathan J. Fortney

    We present an analysis of the early Kepler observations of the previously discovered transiting planet HAT-P-7b. The light curve shows the transit of the star, the occultation of the planet, and the orbit phase-dependent light from the planet. In addition, phase-dependent light from the star is present, known as "ellipsoidal variations". The very nea

  32. T. J. Davidge, T. L. Beck, P. J. McGregor

    The identification of individual stars in crowded environments using photometric information alone is confounded by source confusion. However, with the addition of spectroscopic information it is possible to distinguish between blends and areas where the light is dominated by a single star using the widths of absorption features. We describe a procedure for

  33. Luis A. Caffarelli, Juan L. Vazquez

    We study a porous medium equation, with nonlocal diffusion effects given by an inverse fractional Laplacian operator. We pose the problem in n-dimensional space for all t>0 with bounded and compactly supported initial data, and prove existence of a weak and bounded solution that propagates with finite speed, a property that is nor shared by other fractional

  34. Sunil K. Chebolu, Jan Minac

    C. F. Gauss discovered a beautiful formula for the number of irreducible polynomials of a given degree over a finite field. Assuming just a few elementary facts in field theory and the exclusion-inclusion formula, we show how one see the shape of this formula and its proof instantly.

  35. Vladimir A. Yerokhin, Krzysztof Pachucki

    Rigorous quantum electrodynamical calculation is presented for energy levels of the 1^1S, 2^1S, 2^3S, 2^1P_1, and 2^3P_{0,1,2} states of helium-like ions with the nuclear charge Z=3...12. The calculational approach accounts for all relativistic, quantum electrodynamical, and recoil effects up to orders mα^6 and m^2/Mα^5, thus advancing the previously reporte

  36. Mathew A. Johnson, Kevin Zumbrun

    Extending previous results of Oh--Zumbrun and Johnson--Zumbrun, we show that spectral stability implies linearized and nonlinear stability of spatially periodic traveling-wave solutions of viscous systems of conservation laws for systems of generic type, removing a restrictive assumption that wave speed be constant to first order along the manifold of nearby

  37. Reinier Broker, Kristin Lauter, Andrew V. Sutherland

    We present a new algorithm to compute the classical modular polynomial Phi_n in the rings Z[X,Y] and (Z/mZ)[X,Y], for a prime n and any positive integer m. Our approach uses the graph of n-isogenies to efficiently compute Phi_n mod p for many primes p of a suitable form, and then applies the Chinese Remainder Theorem (CRT). Under the Generalized Riemann Hypo

  38. Peter S. Behroozi, Charlie Conroy, Risa H. Wechsler

    We conduct a comprehensive analysis of the relationship between central galaxies and their host dark matter halos, as characterized by the stellar mass-halo mass (SM-HM) relation, with rigorous consideration of uncertainties. Our analysis focuses on results from the abundance matching technique, which assumes that every dark matter halo or subhalo above a sp

  39. Adrien Richou

    This article deals with the numerical resolution of Markovian backward stochastic differential equations (BSDEs) with drivers of quadratic growth with respect to $z$ and bounded terminal conditions. We first show some bound estimates on the process $Z$ and we specify the Zhang's path regularity theorem. Then we give a new time discretization scheme with

  40. Armen Sedrakian, Jochen Keller

    We compute the finite temperature density response function of nonrelativistic cold fermions with an isotropic condensate. The pair-breaking contribution to the response function is evaluated in the limit of small three-momentum transfers q within an effective theory which exploits series expansion in powers of small q/p_F, where p_F is the Fermi momentum. T

  41. Sourav Chakraborty, Nikhil Devanur, Chinmay Karande

    Identical products being sold at different prices in different locations is a common phenomenon. Price differences might occur due to various reasons such as shipping costs, trade restrictions and price discrimination. To model such scenarios, we supplement the classical Fisher model of a market by introducing {\em transaction costs}. For every buyer $i$ and

  42. A. P. Pyatakov, G. A. Meshkov

    The micromagnetic distribution in a dielectric nanoparticle is theoretically considered. It is shown that the existence of inhomogeneous magnetoelectric interaction in magnetic dielectrics provides the possibility to stabilize the vortex and antivortex state. The estimation of the critical voltage necessary for vortex/antivortex nucleation in bismuth ferrite

  43. R. Miles, T. Ward

    For mixing~$\mathbb Z^d$-actions generated by commuting automorphisms of a compact abelian group, we investigate the directional uniformity of the rate of periodic point distribution and mixing. When each of these automorphisms has finite entropy, it is shown that directional mixing and directional convergence of the uniform measure supported on periodic poi

  44. J. I. Royo Prieto, Martintxo Saralegi-Aranguren

    We construct a Gysin sequence associated to any smooth ${\mathbb S}^3$-action on a smooth manifold.

  45. Abdelhafid Younsi

    We regularized the 3D Navier-Stokes equations by adding a fourth-order viscosity term. We study the upper semicontinuity, of the global attractors of the Leray-Hopf weak solutions of the regularized 3D Navier-Stokes equations, as the artificial dissipation goes to 0. We also consider applications of obtained results to the regularized problem by allowing the

  46. AM Semikhatov

    We study the Yetter--Drinfeld D(B)-module algebra structure on the Heisenberg double H(B^*) endowed with a "heterotic" action of the Drinfeld double D(B). This action can be interpreted in the spirit of Lu's description of H(B^*) as a twist of D(B). In terms of the braiding of Yetter--Drinfeld modules, H(B^*) is braided commutative. By the Brzezi

  47. Bireswar Das, Jacobo Toran, Fabian Wagner

    The Graph Isomorphism problem restricted to graphs of bounded treewidth or bounded tree distance width are known to be solvable in polynomial time [Bod90],[YBFT99]. We give restricted space algorithms for these problems proving the following results: - Isomorphism for bounded tree distance width graphs is in L and thus complete for the class. We also show th

  48. Denis-Charles Cisinski, Goncalo Tabuada

    In this article we further the study of non-commutative motives. Our main result is the construction of a symmetric monoidal structure on the localizing motivator Mot of dg categories. As an application, we obtain : (1) a computation of the spectra of morphisms in Mot in terms of non-connective algebraic K-theory; (2) a fully-faithful embedding of Kontsevich

  49. Chun-Mei Pi, Shu-Hua Yang, Xiao-Ping Zheng

    The radiative viscosity of superfluid $npe$ matter is studied, and it is found that to the lowest order of $δμ/T$ the ratio of radiative viscosity to bulk viscosity is the same as that of the normal matter.

  50. Peter K. F. Kuhfittig

    Exact wormhole solutions, while eagerly sought after, often have the appearance of being overly specialized or highly artificial. A case for the possible existence of traversable wormholes would be more compelling if an abundance of solutions could be found. It is shown in this note that for many of the wormhole geometries in the literature, the exact soluti

  51. Manwai Yuen

    In this paper, we study the blowup of the $N$-dim Euler or Euler-Poisson equations with repulsive forces, in radial symmetry. We provide a novel integration method to show that the non-trivial classical solutions $(ρ,V)$, with compact support in $[0,R]$, where $R>0$ is a positive constant and in the sense which $ρ(t,r)=0$ and $V(t,r)=0$ for $r\geq R$, under

  52. Shingo Takeuchi

    The Jacobian elliptic functions are generalized and applied to a nonlinear eigenvalue problem with $p$-Laplacian. The eigenvalue and the corresponding eigenfunction are represented in terms of common parameters, and a complete description of the spectra and a closed form representation of the corresponding eigenfunctions are obtained. As a by-product of the

  53. Mohamed E. Kelabi, Khaled A. Mazuz, Eman O. Farhat, Howida K. Elgowiry

    From Bohr-Mottelson model, a three parametric simple expression for the ground state rotational band of deformed even-even nuclei is deduced by incorporating the variable moment of inertia and the softness parameter. Our obtained results show good agreement with data in comparison with other existing models.

  54. Julia Bernatska, Petro Holod

    In the paper we obtain equations for large-scale fluctuations of the mean field (the field of magnetization and quadrupole moments) in a magnetic system realized by a square (cubic) lattice of atoms with spin s >= 1 at each site. We use the generalized Heisenberg Hamiltonian with biquadratic exchange as a quantum model. A quantum thermodynamical averaging gi

  55. Xian-Hui Ge, Sang-Jin Sin

    We derive a new acoustic black hole metric from the Abelian Higgs model. In the non-relativistic limit, while the Abelian Higgs model becomes the Ginzburg-Landau model, the metric reduces to an ordinary Unruh type. We investigate the possibility of using (type I and II) superconductors as the acoustic black holes. We propose to realize experimental acoustic

  56. V. Baru, C. Hanhart, Yu. S. Kalashnikova, A. E. Kudryavtsev

    We investigate the interplay of quark and meson degrees of freedom in a physical state representing a near-threshold resonance for the case of a single continuum channel. We demonstrate that such a near-threshold resonance may possess quite peculiar properties if both quark and meson dynamics generate weakly coupled near-threshold poles in the S-matrix. In p

  57. Li Yu

    We introduce an elementary way of constructing principal (Z_2)^m-bundles over compact smooth manifolds. In addition, we will define a general notion of locally standard (Z_2)^m-actions on closed manifolds for all m>0, and then give a general way to construct all such (Z_2)^m-actions from the orbit space. Some related topology problems are also studied.

  58. Alexander P. Pyatakov, Anatoly K. Zvezdin

    Various phenomena related to inhomogeneous magnetoelectric interaction are considered. The interrelation between spatial modulation of order parameter and electric polarization, known as flexoelectric effect in liquid crystals, in the case of magnetic media appears in a form of electric polarization induced by spin modulation and vice versa. This flexomagnet

  59. Yassine Gargouri, Chawki Hajjem, Vincent Lariviere, Yves Gingras

    Articles whose authors make them Open Access (OA) by self-archiving them online are cited significantly more than articles accessible only to subscribers. Some have suggested that this "OA Advantage" may not be causal but just a self-selection bias, because authors preferentially make higher-quality articles OA. To test this we compared self-selectiv

  60. Paul Poncet

    The recent extensions of domain theory have proved particularly efficient to study lattice-valued maxitive measures, when the target lattice is continuous. Maxitive measures are defined analogously to classical measures with the supremum operation in place of the addition. Building further on the links between domain theory and idempotent analysis highlighte

  61. Parthapratim Pradhan, Parthasarathi Majumdar

    Circular null geodesic orbits, in extremal Reissner-Nordstrom spacetimes, are examined with regard to their stability, and compared with similar orbits in the near-extremal situation. Extremization of the effective potential for null circular orbits shows the existence of a stable circular geodesic in the extremal spacetime, precisely {\it on} the event hori

  62. Narinder S Claire

    We give a direct non-abstract proof of the Spectral Mapping Theorem for the Helffer-Sjöstrand functional calculus for linear operators on Banach spaces with real spectra and consequently give a new non-abstract direct proof for the Spectral Mapping Theorem for self-adjoint operators on Hilbert spaces. Our exposition is closer in spirit to the proof by explic

  63. Ceyhun Bulutay, Mustafa Kulakci, Raşit Turan

    Demonstrating the quantum-confined Stark effect (QCSE) in silicon nanocrystals (NCs) embedded in oxide has been rather elusive, unlike the other materials. Here, the recent experimental data from ion-implanted Si NCs is unambiguously explained within the context of QCSE using an atomistic pseudopotential theory. This further reveals that the majority of the

  64. David Windisch

    We study the entropy of the distribution of the set R_n of vertices visited by a simple random walk on a graph with bounded degrees in its first n steps. It is shown that this quantity grows linearly in the expected size of R_n if the graph is uniformly transient, and sublinearly in the expected size if the graph is uniformly recurrent with subexponential vo

  65. Pi-Gang Luan

    Recently, a new energy density formula for electromagnetic waves in the metamaterial consisting of arrays of conducting wires and split-ring-resonators (SRR) has been derived [Phys. Rev. E 80, 046601 (2009), arXiv:0909.1043]. According to that formula, the positiveness is obvious for the electric part of the energy density but not clear for the magnetic part

  66. Tasho Kaletha

    To a maximal torus in a quasi-split semi-simple simply-connected group over a local field of characteristic 0, Langlands and Shelstad construct a cohomological invariant called the splitting invariant, which is an important component of their endoscopic transfer factors. We study this invariant in the case of a split real group and prove a decomposition theo

  67. Damian J. H. Markham

    We investigate the relationship between multipartite entanglement and symmetry, focusing on permutation symmetric states. We use the Majorana representation, where these states correspond to points on a sphere. Symmetry of the representation under rotation is equivalent to symmetry of the states under products of local unitaries. The geometric measure of ent

  68. Sandra S Padula, Danuce M Dudek, O Socolowski

    Squeezed correlations of hadron-antihadron pairs are predicted to appear if their masses are modified in the hot and dense medium formed in high energy heavy ion collisions. If discovered experimentally, they would be an unequivocal evidence of in-medium mass shift found by means of hadronic probes. We discuss a method proposed to search for this novel type

  69. Qing Zhou

    The problem of motif detection can be formulated as the construction of a discriminant function to separate sequences of a specific pattern from background. In computational biology, motif detection is used to predict DNA binding sites of a transcription factor (TF), mostly based on the weight matrix (WM) model or the Gibbs free energy (FE) model. However, d

  70. Kikuo Asai

    We investigated the role of HUDs in CAI. HUDs have been used in various situations in daily lives by recent downsizing and cost down of the display devices. CAI is one of the promising applications for HUDs. We have developed an HUD-based CAI system for effectively presenting instructions of the equipment in the transportable earth station. This chapter desc

  71. Junia Coutinho Anacleto, Aparecido Fabiano Pinatti de Carvalho

    The advent of Web 3.0, claiming for personalization in interactive systems (Lassila & Hendler, 2007), and the need for systems capable of interacting in a more natural way in the future society flooded with computer systems and devices (Harper et al., 2008) show that great advances in HCI should be done. This chapter presents some contributions of LIA for th

  72. K. Kolenberg, R. Szabó, D. W. Kurtz, R. L. Gilliland

    We present the first results of our analyses of selected RR Lyrae stars for which data have been obtained by the Kepler Mission. As expected, we find a significant fraction of the RRab stars to show the Blazhko effect, a still unexplained phenomenon that manifests itself as periodic amplitude and phase modulations of the light curve, on time scales of typica

  73. Gibor Basri, Lucianne M. Walkowicz, Natalie Batalha, Ronald L. Gilliland

    The Kepler mission provides an exciting opportunity to study the lightcurves of stars with unprecedented precision and continuity of coverage. This is the first look at a large sample of stars with photometric data of a quality that has heretofore been only available for our Sun. It provides the first opportunity to compare the irradiance variations of our S

  74. Y. Jack Ng

    Due to quantum fluctuations, probed at small scales, spacetime is very complicated -- something akin in complexity to a turbulent froth which the late John Wheeler dubbed quantum foam, aka spacetime foam. Our recent work suggests that (1) we may be close to being able to detect quantum foam with extragalactic sources once the Very Large Telescope Interferome

  75. Natalya A. Zimbovskaya

    We have carried out calculations of current-voltage characteristics for the electron tunnel current through a junction with a thin insulating ferroelectric barrier assuming that interface transmissions for the left and right interfaces noticeably differ due to dissimilarity of the interfaces. Obtained conductance versus voltage and current versus voltage cur

  76. A. V. Latyshev, A. A. Yushkanov

    We construct a kinetic equation simulating the behavior of degenerate quantum Bose gases with the collision rate proportional to the molecule velocity. We obtain an analytic solution of the half--space boundary--value Smoluchowski problem of the temperature jump at the interface between the degenerate Bose gas and the condensed phase.

  77. Nader H. Bshouty, Hanna Mazzawi

    In this paper we consider the problem of reconstructing a hidden weighted hypergraph of constant rank using additive queries. We prove the following: Let $G$ be a weighted hidden hypergraph of constant rank with n vertices and $m$ hyperedges. For any $m$ there exists a non-adaptive algorithm that finds the edges of the graph and their weights using $$ O(\fra

  78. Leslie Hebb, A. Collier-Cameron, A. H. M. J. Triaud, T. A. Lister

    We report on the discovery of a new extremely short period transiting extrasolar planet, WASP-19b. The planet has mass Mpl = 1.15 \pm 0.08 MJ, radius Rpl = 1.31 \pm 0.06 RJ, and orbital period P = 0.7888399 \pm 0.0000008 days. Through spectroscopic analysis, we determine the host star to be a slightly super-solar metallicity ([M/H] = 0.1 \pm 0.1 dex) G-dwarf

  79. A. Gutierrez-Rodriguez, E. Torres-Lomas, A. Gonzalez-Sanchez

    We calculate the emissivity due to neutrino-pair production in $e^+e^-$ annihilation in the context of a left-right symmetric model in a way that can be used in supernova calculations. We also present some simple estimates which show that such process can act as an efficient energy-loss mechanism in the shocked supernova core. We find that the emissivity is

  80. S. Hekker, J. Debosscher, D. Huber, M. G. Hidas

    Oscillating stars in binary systems are among the most interesting stellar laboratories, as these can provide information on the stellar parameters and stellar internal structures. Here we present a red giant with solar-like oscillations in an eclipsing binary observed with the NASA Kepler satellite. We compute stellar parameters of the red giant from spectr

  81. P. Perez-Fernandez, A. Relano, J. M. Arias, J. Dukelsky

    The decoherence induced on a single qubit by its interaction with the environment is studied. The environment is modelled as a scalar two-level boson system that can go through either first order or continuous excited state quantum phase transitions, depending on the values of the control parameters. A mean field method based on the Tamm-Damkoff approximatio

  82. A. Relano, J. M. Arias, J. Dukelsky, J. E. Garcia-Ramos

    We analyze the decoherence induced on a single qubit by the interaction with a two-level boson system with critical internal dynamics. We explore how the decoherence process is affected by the presence of quantum phase transitions in the environment. We conclude that the dynamics of the qubit changes dramatically when the environment passes through a continu

  83. Aurel Bulgac

    At present there are two vastly different ab initio approaches to the description of the the many-body dynamics: the Density Functional Theory (DFT) and the functional integral (path integral) approaches. On one hand, if implemented exactly, the DFT approach can allow in principle the exact evaluation of arbitrary one-body observable. However, when applied t

  84. Oren Bergman, Gilad Lifschytz

    We describe brane configurations that interpolate between the N=6 AdS4xCP3 background of Type IIA supergravity and the N=0 AdS4xCP3 background of massive Type IIA supergravity. Using the T-dual Type IIB configurations we prove that this leads to unequal Chern-Simons levels in the dual gauge theory, and find the precise relation between the parameters of the

  85. N. M. Batalha, J. F. Rowe, R. L. Gilliland, J. J. Jenkins

    Ten days of commissioning data (Quarter 0) and thirty-three days of science data (Quarter 1) yield instrumental flux timeseries of ~150,000 stars that were combed for transit events, termed Threshold Crossing Events (TCE), each having a total detection statistic above 7.1-sigma. TCE light curves are modeled as star+planet systems. Those returning a companion

  86. Antonio Pich

    The total tau hadronic width can be accurately calculated using analyticity and the operator product expansion. The result turns out to be very sensitive to the value of alpha_s(m_tau^2), providing a precise determination of the strong coupling constant. The theoretical description of this observable is updated, including the recently computed O(alpha_s^4) c

  87. M. Saralegi-Aranguren, R. Wolak

    We prove that the basic intersection cohomology $ {I H}^{^{*}}_{_{\bar{p}}}{(M/\mathcal{F})}, $ where $\mathcal{F}$ is the singular foliation determined by an isometric action of a Lie group $G$ on the compact manifold $M$, is finite dimensional.

  88. Manwai Yuen

    This article extends the previous paper in "M.W. Yuen, \textit{Stabilities for Euler-Poisson Equations in Some Special Dimensions}, J. Math. Anal. Appl. \textbf{344} (2008), no. 1, 145--156.", from the Euler-Poisson equations for attractive forces to the repulsive ones in $R^{N}$ $(N\geq2)$. The similar stabilities of the system are studied. Addition

  89. Denis Petrovich Ilyutko, Vassily Olegovich Manturov

    The present paper is a review of the current state of Graph-Link Theory (graph-links are also closely related to homotopy classes of looped interlacement graphs), dealing with a generalisation of knots obtained by translating the Reidemeister moves for links into the language of intersection graphs of chord diagrams. In this paper we show how some methods of

  90. Boris Doubrov, Olga Radko

    The paper gives the complete characterization of all graded nilpotent Lie algebras with infinite-dimensional Tanaka prolongation as extensions of graded nilpotent Lie algebras of lower dimension by means of a commutative ideal. We introduce a notion of weak characteristics of a vector distribution and prove that if a bracket-generating distribution of consta

  91. Laura Gioia Andrea Keller

    $L^{\infty}$ estimates in the integrability by compensation result of H. Wente fail in dimension larger than two when Sobolev spaces are replaced by the ad-hoc Morrey spaces. However, in this paper we prove that $L^{\infty}$ estimates hold in arbitrary dimension when Morrey spaces are replaced by their Littlewood Paley counterparts: Besov-Morrey spaces. As a

  92. Julia Bernatska, Petro Holod

    We propose a general scheme for separation of variables in the integrable Hamiltonian systems on orbits of the loop algebra $\mathfrak{sl}(2,\Complex)\times \mathcal{P}(λ,λ^{-1})$. In particular, we illustrate the scheme by application to modified Korteweg--de Vries (MKdV), sin(sinh)-Gordon, nonlinear Schrödinger, and Heisenberg magnetic equations.

  93. Julia Bernatska, Petro Holod

    We construct a class of topological excitations of a mean field in a two-dimensional spin system represented by a quantum Heisenberg model with high powers of exchange interaction. The quantum model is associated with a classical one (the continuous classical analogue) that is based on a Landau-Lifshitz like equation, and describes large-scale fluctuations o

  94. O. Tchikilev, S. Akimenko, G. Britvich, A. Filin

    Using data collected with the ISTRA+ spectrometer at U70 proton synchrotron of IHEP, we report the first measurement of the destructive interference in the radiative kaon cecay K- -->mu-nugamma. We find the difference of the vector and axial form factors Fv-Fa=0.126+/-0.027+/-0.043. The measured value is two standard deviations above the O(p**4) ChPT predict

  95. Julia Bernatska, Petro Holod

    We study ordered states and topological excitations in a quasi-two-dimensional magnet, modeled by a square lattice with spins $s {=} 1$ at all sites, and the Hamiltonian with biquadratic exchange interaction between nearest neighbor sites. We propose two effective Hamiltonians for description of large-scale excitations in the two-dimensional case. They descr

  96. Alex Kontorovich, Hee Oh

    For the ternary quadratic form Q(x) = x^2 + y^2 - z^2 and a non-zero Pythagorean triple x_0 in Z^3 lying on the cone Q(x) = 0, we consider an orbit O = x_0 Gamma of a finitely generated subgroup Gamma < SO_Q(Z) with critical exponent exceeding 1/2. We find infinitely many Pythagorean triples in O whose hypotenuse, area, and product of side lengths have few p

  97. A. G. Ramm

    Let $F(u)=h$ be an operator equation in a Banach space $X$, $\|F&#39;(u)-F&#39;(v)\|\leq ω(\|u-v\|)$, where $ω\in C([0,\infty))$, $ω(0)=0$, $ω(r)>0$ if $r>0$, $ω(r)$ is strictly growing on $[0,\infty)$. Denote $A(u):=F&#39;(u)$, where $F&#39;(u)$ is the Fréchet derivative of $F$, and $A_a:=A+aI.$ Assume that (*) $\|A^{-1}_a(u)\|\leq \frac{c_1}{|a|^b}$, $|a|>

  98. A. G. Ramm

    Let $G(k)=\int_0^1g(x)e^{kx}dx$, $g\in L^1(0,1)$. The main result of this paper is the following theorem. {\bf Theorem}. {\it If $\limsup_{k\to +\infty}|G(k)|<\infty$, then $g=0$. There exists $g\not\equiv 0$, $g\in L^1(0,1)$, such that $G(k_j)=0$, $k_j<k_{j+1}$, $\lim_{j\to \infty}k_j=\infty$, $\lim_{k\to \infty}|G(k)|$ does not exist, $\limsup_{k\to +\inft

  99. A. G. Ramm

    A new understanding of the notion of the stable solution to ill-posed problems is proposed. The new notion is more realistic than the old one and better fits the practical computational needs. A method for constructing stable solutions in the new sense is proposed and justified. The basic point is: in the traditional definition of the stable solution to an i

  100. I. M. Narodetskii, Yu. A. Simonov, A. I. Veselov

    We use the screened Coulomb potential with $r$-dependent coupling constant and the non--perturbative quark--antiquark potential derived within Field Correlator Method (FCM) to calculate $J/ψ$ and $Υ$ binding energies and melting temperatures in the deconfined phase of quark-gluon plasma.