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March 2009 arXiv papers — page 50

Showing 4,9015,000 of 5,470 papers

  1. Martin J. Bridgeman

    Given a measured lamination on a finite area hyperbolic surface we consider a natural measure Mon the real line obtained by taking the push-forward of the volume measure of the unit tangent bundle of the surface under an intersection function associated with the lamination. We show that the measure M gives summation identities for the Rogers dilogarithm func

  2. Raymond Chi-Wing Wong, Ada Wai-Chee Fu, Jia Liu, Ke Wang

    While previous works on privacy-preserving serial data publishing consider the scenario where sensitive values may persist over multiple data releases, we find that no previous work has sufficient protection provided for sensitive values that can change over time, which should be the more common case. In this work we propose to study the privacy guarantee fo

  3. C. S. Leem, B. J. Kim, Chul Kim, S. R. Park

    We obtained the spectral function of the graphite H point using high resolution angle resolved photoelectron spectroscopy (ARPES). The extracted width of the spectral function (inverse of the photo-hole lifetime) near the H point is approximately proportional to the energy as expected from the linearly increasing density of states (DOS) near the Fermi energy

  4. Zhongzhi Zhang, Yi Qi, Shuigeng Zhou, Wenlei Xie

    The explicit determinations of the mean first-passage time (MFPT) for trapping problem are limited to some simple structure, e.g., regular lattices and regular geometrical fractals, and determining MFPT for random walks on other media, especially complex real networks, is a theoretical challenge. In this paper, we investigate a simple random walk on the the

  5. Yu Tanaka

    We define a problem "exact non-identity check": Given a classical description of a quantum circuit with an ancilla system, determine whether it is strictly equivalent to the identity or not. We show that this problem is NQP-complete. In a sense of the strict equivalence condition, this problem is different from a QMA-complete problem, non-identity ch

  6. Sutirtha Mukhopadhyay, Sangwon Oh, A M Mounce, Moohee Lee

    NMR measurements have been performed on single crystals of Ba$_{1-x}$K$_{x}$Fe$_2$As$_2$ (x = 0, 0.45) and CaFe$_2$As$_2$ grown from Sn flux. The Ba-based pnictide crystals contain significant amounts of Sn in their structure, $\sim 1$%, giving rise to magnetic impurity effects evident in the NMR spectrum and in the magnetization. Our experiments show that t

  7. Robby G. McKilliam, Warren D. Smith, I. Vaughan L. Clarkson

    The Coxeter lattices, which we denote $A_{n/m}$, are a family of lattices containing many of the important lattices in low dimensions. This includes $A_n$, $E_7$, $E_8$ and their duals $A_n^*$, $E_7^*$ and $E_8^*$. We consider the problem of finding a nearest point in a Coxeter lattice. We describe two new algorithms, one with worst case arithmetic complexit

  8. T. Joseph W. Lazio, C. L. Brogan, W. M. Goss, S. Stanimirovic

    This paper reports dual-epoch, Very Long Baseline Array observations of H I absorption toward 3C 147. One of these epochs (2005) represents new observations while one (1998) represents the reprocessing of previous observations to obtain higher signal-to-noise results. Significant H I opacity and column density variations, both spatially and temporally, are o

  9. Shufang Su, Brooks Thomas

    In this work, we examine a two-Higgs-doublet extension of the Standard Model in which one Higgs doublet is responsible for giving mass to both up- and down-type quarks, while a separate doublet is responsible for giving mass to leptons. We examine both the theoretical and experimental constraints on the model and show that large regions of parameter space ar

  10. Matthew R. McKay, Iain B. Collings, Antonia M. Tulino

    This paper investigates the achievable sum rate of multiple-input multiple-output (MIMO) wireless systems employing linear minimum mean-squared error (MMSE) receivers. We present a new analytic framework which unveils an interesting connection between the achievable sum rate with MMSE receivers and the ergodic mutual information achieved with optimal receive

  11. Jesper Rasmussen, Jesper Sommer-Larsen, Kristian Pedersen, Sune Toft

    Models of disk galaxy formation commonly predict the existence of an extended reservoir of accreted hot gas surrounding massive spirals at low redshift. As a test of these models, we use X-ray and H-alpha data of the two massive, quiescent edge-on spirals NGC 5746 and NGC 5170 to investigate the amount and origin of any hot gas in their halos. Contrary to ou

  12. Yong Zeng, Jerome V. Moloney

    A new near-to-far-field transformation algorithm for three-dimensional finite-different time-domain is presented in this article. This new approach is based directly on the polarization current of the scatterer, not the scattered near fields. It therefore eliminates the numerical errors originating from the spatial offset of the E and H fields, inherent in t

  13. Jacob D. Feala, Jorge Cortes, Phillip M. Duxbury, Carlo Piermarocchi

    Effective therapy of complex diseases requires control of highly non-linear complex networks that remain incompletely characterized. In particular, drug intervention can be seen as control of signaling in cellular networks. Identification of control parameters presents an extreme challenge due to the combinatorial explosion of control possibilities in combin

  14. Gia Dvali, Ignacy Sawicki, Alexander Vikman

    We propose a cosmological scenario based on the assumption that the Standard Model possesses a large number of copies. It is demonstrated that baryons in the hidden copies of the standard model can naturally account for the dark matter. The right abundance of the hidden-sector baryons and the correct spectrum of density perturbations are simultaneously gener

  15. D. Labardini-Fragoso, M. Neumann-Coto, M. Takane

    If a convex body C has modular and irreducible face lattice (and is not strictly convex), there is a face-preserving homeomorphism from C to a section of a cone of hermitian matrices or C has dimension 8, 14 or 26.

  16. Francesco Benini, Anatoly Dymarsky, Sebastian Franco, Shamit Kachru

    We discuss gravitational backgrounds where supersymmetry is broken at the end of a warped throat, and the SUSY-breaking is transmitted to the Standard Model via gauginos which live in (part of) the bulk of the throat geometry. We find that the leading effect arises from splittings of certain "messenger mesons," which are adjoint KK-modes of the D-branes supp

  17. Ken J. Shen, Lars Bildsten

    AM Canum Venaticorum (AM CVn) binaries consist of a degenerate helium donor and a helium, C/O, or O/Ne WD accretor, with accretion rates of Mdot = 1e-13 - 1e-5 Msol/yr. For accretion rates < 1e-6 Msol/yr, the accreted helium ignites unstably, resulting in a helium flash. As the donor mass and Mdot decrease, the ignition mass increases and eventually becomes

  18. Igor F. Herbut

    It is shown that in the absence of spontaneous symmetry breaking the Dirac cones in the system of interacting electrons on honeycomb lattice are isotropic at low energies. The effect is due to the $Z_3$ subgroup of the $D_3$ symmetry group of the dispersion relation of Dirac quasiparticles. Consequences of the violations of the $Z_3$ or the sublattice symmet

  19. Kamthorn Chailuek, Brian C. Hall

    We consider the weighted Bergman spaces HL^2(B^d,μ_λ), where dμ_λ(z)=c_λ(1-|z|^2)^lambda dτ, τbeing the hyperbolic volume measure. These spaces are nonzero if and only if λ>d. For 0<λ\leq d, spaces with the same formula for the reproducing kernel can be defined using a Sobolev-type norm. We define Toeplitz operators on these generalized Bergman spaces and in

  20. N. A. Carella

    The article focuses on the problems of prime gaps and zero spacings. Possible solutions of several related problems such as the greatest lower bound, the least upper bound of the zero spacings, and the least upper bound of the prime gaps are considered.

  21. V. V. Bavula

    We study in detail the %Shrek algebra $\mS_n$ in the title which is an algebra obtained from a polynomial algebra $P_n$ in $n$ variables by adding commuting, {\em left} (but not two-sided) inverses of the canonical generators of $P_n$. The algebra $\mS_n$ is non-commutative and neither left nor right Noetherian but the set of its ideals satisfies the a.c.c.,

  22. David Andriot, Ruben Minasian, Michela Petrini

    It is well known that a constant O(n,n,Z) transformation can relate different string backgrounds with n commuting isometries that have very different geometric and topological properties. Here we construct discrete families of (flux) backgrounds on internal manifolds of different topologies by performing certain coordinate dependent O(d,d) transformations, w

  23. Vladislav Kargin

    Suppose that $X_1,\...,X_n,\...$ are i.i.d. rotationally invariant $N$-by-$N$ matrices. Let $Π_n=X_n\... X_1$. It is known that $n^{-1}\log |Π_n|$ converges to a nonrandom limit. We prove that under certain additional assumptions on matrices $X_i$ the speed of convergence to this limit does not decrease when the size of matrices, $N$, grows.

  24. Benjamin A. Burrington, Jacob Sonnenschein

    We study the dynamics of probe D7 $\overline{\rm D7}$ flavor probe branes in the background of near extremal D5 branes. This model is a holographic dual to a gauge theory with spontaneous breaking of a $U(N_f)_L\times U(N_f)_R$ chiral symmetry. The spectrum of two such D7 $\overline{\rm D7}$ embeddings, contains a single massive 4D meson coming from the worl

  25. Yi-Fu Cai, Wei Xue, Robert Brandenberger, Xinmin Zhang

    A nonsingular bouncing cosmology in which the scales of interest today exit the Hubble radius in a matter-dominated contracting phase yields an alternative to inflation for producing a scale-invariant spectrum of adiabatic cosmological fluctuations. In this paper we identify signatures in the non-Gaussianities of the fluctuations which are specific to this s

  26. M. Kargarian, R. Jafari, A. Langari

    In this paper the the effect of Dzyaloshinskii-Moriya interaction and anisotropy on the Entanglement of Heisenberg chain has been studied. While the anisotropy suppress the entanglement due to favoring of the alignment of spins, the DM interaction restores the spoiled entanglement via creation of the quantum fluctuations. Thermodynamic limit of the model and

  27. Julian Sonner

    In this paper we initiate the study of SSB in 3+1 dimensional rotating, charged, asymptotically AdS black holes. The theory living on their boundary, R x S^2, has the interpretation of a 2+1 dimensional rotating holographic superconductor. We study the appearance of a marginal mode of the condensate as the temperature is decreased. We find that the transitio

  28. Shui Feng, Wei Sun

    The two parameter Poisson-Dirichlet distribution $PD(α,θ)$ is the distribution of an infinite dimensional random discrete probability. It is a generalization of Kingman&#39;s Poisson-Dirichlet distribution. The two parameter Dirichlet process $Π_{α,θ,ν_0}$ is the law of a pure atomic random measure with masses following the two parameter Poisson-Dirichlet di

  29. J. F. Sepinsky, B. Willems, V. Kalogera, F. A. Rasio

    We investigate the secular evolution of the orbital semi-major axis and eccentricity due to mass transfer in eccentric binaries, allowing for both mass and angular momentum loss from the system. Adopting a delta function mass transfer rate at the periastron of the binary orbit, we find that, depending on the initial binary properties at the onset of mass tra

  30. T. S. Metcalfe, O. L. Creevey, J. Christensen-Dalsgaard

    Over the past two decades, helioseismology has revolutionized our understanding of the interior structure and dynamics of the Sun. Asteroseismology will soon place this knowledge into a broader context by providing structural data for hundreds of Sun-like stars. Solar-like oscillations have already been detected from the ground in several stars, and NASA&#39

  31. Marc Casals, Sam R. Dolan, Adrian C. Ottewill, Barry Wardell

    We present the first application of the Poisson-Wiseman-Anderson method of matched expansions, to compute the self-force acting on a point particle moving in a curved spacetime. The method uses two expansions for the Green function, valid in `quasilocal&#39; and `distant past&#39; regimes, which are matched within the normal neighbourhood. We perform our cal

  32. Chun-Yeol You, Jae-Ho Han, Hyun-Woo Lee, Kyung-Jin Lee

    This paper has been withdrawn by the author due to a serious errors in the calculations.

  33. D. Emmanuel-Costa, C. Simoes

    All quark mass matrices with texture zeroes obtained through weak basis transformations are confronted with the experimental data. The reconstruction of the quark mass matrices M_u and M_d at the electroweak scale is performed in a weak basis where the matrices are Hermitian and have a maximum of three vanishing elements. The same procedure is also accomplis

  34. Vijay Kumar, Washington Taylor

    We consider &#34;magnetized brane&#34; compactifications of the type I/heterotic string on K3 with U(1) background fluxes. The nonabelian gauge group and matter content of the resulting six-dimensional vacua are parameterized by a matrix encoding a lattice contained within the even, self-dual lattice Gamma^{3,19}. Mathematical results of Nikulin on lattice e

  35. Rodolfo A. Diaz, William J. Herrera

    We prove that the matrix of capacitance in electrostatics is a positive-singular matrix with a non-degenerate null eigenvalue. We explore the physical implications of this fact, and study the physical meaning of the eigenvalue problem for such a matrix. Many properties are easily visualized by constructing a &#34;potential space&#34; isomorphic to the euclid

  36. M. I. Ostrovskii

    The main purpose of the paper is to find some expansion properties of locally finite metric spaces which do not embed coarsely into a Hilbert space. The obtained result is used to show that infinite locally finite graphs excluding a minor embed coarsely into a Hilbert space. In an appendix a direct proof of the latter result is given.

  37. M. Grossi, S. di Serego Alighieri, C. Giovanardi, G. Gavazzi

    We present the analysis of the HI content of a sample of early-type galaxies (ETGs) in low-density environments (LDEs) using the data set provided by the Arecibo Legacy Fast ALFA (ALFALFA) survey. We compare their properties to the sample in the Virgo cluster that we studied in a previous paper (di Serego Alighieri et al. 2007, Paper I). We have selected a s

  38. Javier Ballesteros-Paredes, Gilberto C. Gomez, Laurent Loinard, Rosa M. Torres

    Only a few molecular clouds in the Solar Neighborhood exhibit the formation of only low-mass stars. Traditionally, these clouds have been assumed to be supported against more vigorous collapse by magnetic fields. The existence of strong magnetic fields in molecular clouds, however, poses serious problems for the formation of stars and of the clouds themselve

  39. The CLEO Collaboration, J. Yelton

    We measure the absolute branching fractions of $\Ds$ semileptonic decays where the hadron in the final state is one of $ϕ$, $η$, $\etap$, $\Ks$, $\Kstar$, and $f_0$, using $2.8 \times 10^5$ $\epm \to \Ds\Dsstar$ decays collected in the CLEO-c detector at a center-of-mass energy close to 4170 MeV. We obtain ${\cal B}(\Dsp\to ϕe^+ ν_e) =(2.29\pm 0.37 \pm 0.11)

  40. Alejandro W. Rodriguez, Alexander P. McCauley, John D. Joannopoulos, Steven G. Johnson

    We present the basic ingredients of a technique to compute quantum Casimir forces at micrometer scales using antenna measurements at tabletop, e.g. centimeter, scales, forming a type of analog computer for the Casimir force. This technique relies on a correspondence that we derive between the contour integration of the Casimir force in the complex frequency

  41. Peter Sheridan Dodds, Joshua L. Payne

    We analytically determine when a range of abstract social contagion models permit global spreading from a single seed on degree-correlated random networks. We deduce the expected size of the largest vulnerable component, a network&#39;s tinderbox-like critical mass, as well as the probability that infecting a randomly chosen individual seed will trigger glob

  42. A. Alonso Izquierdo, M. A. Gonzalez Leon, J. Mateos Guilarte

    The stability of the kinks of the non-linear ${\mathbb S}^2$-sigma model discovered in Phys. Rev. Lett. 101(2008)131602 is discussed from several points of view. After a direct estimation of the spectra of the second-order fluctuation operators around topological kinks, first-order field equations are proposed to distinguish between BPS and non-BPS kinks. Th

  43. Sheng Wang

    CLeFAPS, a fast and flexible pairwise structural alignment algorithm based on a rigid-body framework, namely CLePAPS, is proposed. Instead of allowing twists (or bends), the flexible in CLeFAPS means: (a) flexibilization of the algorithm&#39;s parameters through self-adapting with the input structures&#39; size, (b) flexibilization of adding the aligned frag

  44. Jong Hyun Kim

    Louis W. Shapiro gave a combinatorial proof of a bilinear generating function for Chebyshev polynomials equivalent to the formula 1/(1-ax-x^2) * 1/(1-bx-x^2) = (1-x^2)/(1-abx-(2+a^2+b^2)x^2 -abx^3+x^4), where * denotes the Hadamard product. In a similar way, by considering tilings of a 2 by n rectangle with 1 by 1 and 1 by 2 bricks in the top row, and 1 by 1

  45. Margarita Sharina, Emmanuel Davoust

    We present the results of spectroscopic observations of eight globular cluster candidates in NGC147, a satellite dwarf elliptical galaxy of M31. Our goal is to make a complete inventory of the globular cluster system of this galaxy, determine the properties of their stellar populations, and compare these properties with those of systems of globular clusters

  46. Geraldo Botelho, Daniel Pellegrino, Pilar Rueda

    Cotype is used in this paper to prove new results concerning the existence of non-absolutely summing linear operators between Banach spaces. We derive consequences that extend/generalize/ complement some classic results. We also point out that some of our results are sharp.

  47. J. F. Gomes, G. R. de Melo, A. H. Zimerman

    The algebraic structure of the integrable mixed mKdV/sinh-Gordon model is discussed and \textit{}extended to the AKNS/Lund-Regge model and to its corresponding supersymmetric versions. The integrability of the models is guaranteed from the zero curvature representation and some soliton solutions are discussed.

  48. H. Choi, F. Borondics, D. A. Siegel, S. Y. Zhou

    We study the broadband optical conductivity and ultrafast carrier dynamics of epitaxial graphene in the few-layer limit. Equilibrium spectra of nominally buffer, monolayer, and multilayer graphene exhibit significant terahertz and near-infrared absorption, consistent with a model of intra- and interband transitions in a dense Dirac electron plasma. Non-equil

  49. Todor Stanev

    We describe the design and performance of IceTop, the air shower array on top of the IceCube neutrino detector. After the 2008/09 antarctic summer season both detectors are deployed at almost 3/4 of their design size. With the current IceTop 59 stations we can start the study of showers of energy well above 10$^{17}$ eV. The paper also describes the first re

  50. Geoffrey T. Bodwin, Xavier Garcia i Tormo, Jungil Lee

    We outline a proof of factorization in exclusive processes, taking into account the presence of soft and collinear modes of arbitrarily low energy, which arise when the external lines of the process are taken on shell. Specifically, we examine the process of e^+e^- annihilation through a virtual photon into two light mesons. In an intermediate step, we estab

  51. R. Ciolfi, V. Ferrari, L. Gualtieri, J. A. Pons

    We find general relativistic solutions of equilibrium magnetic field configurations in magnetars, extending previous results of Colaiuda et al. (2008). Our method is based on the solution of the relativistic Grad-Shafranov equation, to which Maxwell&#39;s equations can be reduced in some limit. We obtain equilibrium solutions with the toroidal magnetic field

  52. Steven Weinberg

    This is the written version of a talk given in memory of Gunnar Källén, at the Departments of Theoretical Physics, Physics, and Astronomy of Lund University on February 13, 2009. It will be published in a collection of the papers of Gunnar Källén, edited by C. Jarlskog and A. C. T. Wu. I discuss some of Källén&#39;s work, especially regarding the problem of

  53. Jean-Pierre Tillich, Gilles Zemor

    The current best asymptotic lower bound on the minimum distance of quantum LDPC codes with fixed non-zero rate is logarithmic in the blocklength. We propose a construction of quantum LDPC codes with fixed non-zero rate and prove that the minimum distance grows proportionally to the square root of the blocklength.

  54. E. A. Paschos, Dario Schalla

    In this paper we present quantitative results for coherent pion production by neutrinos scattered off nuclei within the framework developed by Gounaris, Kartavtsev and Paschos. The method is based on PCAC and uses helicity cross sections for the scattering of weak gauge bosons on nuclei. The process relies on experimental data for elastic pion-nucleus scatte

  55. Frederic Campana

    The results known for Green-Lazarsfeld sets and solvable or nilpotent quotients of Kaehler groups are extended to the class of (compact Kaehler) geometric orbifolds with finite and integral multiplicities. The proofs are by reduction to the known case of compact Kaehler manifolds.

  56. Xiangdong Ji, Tower Wang

    We investigate the cosmological perturbations in generalized gravity, where the Ricci scalar and a scalar field are non-minimally coupled via an arbitrary function. In the Friedmann-Lemaitre-Robertson-Walker background, by studying the linear perturbation theory, we separate the scalar type perturbations into the curvature perturbation and the entropy pertur

  57. P. Coelho, C. Mendes de Oliveira, R. Cid Fernandes

    We obtained long-slit spectra of high signal-to-noise ratio of the galaxy M32 with the GMOS spectrograph at the GEMINI North telescope. We analysed the integrated spectra by means of full spectral fitting in order to extract the mixture of stellar populations that best represents its composite nature. Three different galactic radii were analysed, from the nu

  58. Yan Liu, Ya-Wen Sun

    In this note we study the properties of linearized gravitational excitations in the new massive gravity theory in asymptotically $AdS_3$ spacetime and find that there is also a critical point for the mass parameter at which massive gravitons become massless as in topological massive gravity in $AdS_3$. However, at this critical point in the new massive gravi

  59. Li-Chia Choo, Kai-Kit Wong

    In this paper, bounds to the rate-equivocation region for the general 3-receiver broadcast channel (BC) with degraded message sets, are presented for confidential messages to be kept secret from one of the receivers. This model is more general than the 2-receiver BCs with confidential messages with an external wiretapper, and the recently studied 3-receiver

  60. Robin A. Moser, Gábor Tardos

    The Lovasz Local Lemma [EL75] is a powerful tool to non-constructively prove the existence of combinatorial objects meeting a prescribed collection of criteria. In his breakthrough paper [Bec91], Beck demonstrated that a constructive variant can be given under certain more restrictive conditions. Simplifications of his procedure and relaxations of its restri

  61. A. Bisio, G. Chiribella, G. M. D&#39;Ariano, S. Facchini

    We address the problem of learning an unknown unitary transformation from a finite number of examples. The problem consists in finding the learning machine that optimally emulates the examples, thus reproducing the unknown unitary maximum fidelity. Learning a unitary is equivalent to storing it in the state of a quantum memory (the memory of the learning mac

  62. Péter Lévay, Metod Saniga, Péter Vrana, Petr Pracna

    It is shown that the $E_{6(6)}$ symmetric entropy formula describing black holes and black strings in D=5 is intimately tied to the geometry of the generalized quadrangle GQ$(2,4)$ with automorphism group the Weyl group $W(E_6)$. The 27 charges correspond to the points and the 45 terms in the entropy formula to the lines of GQ$(2,4)$. Different truncations w

  63. Dietrich Hafner, Jean-Philippe Nicolas

    On arbitrary spacetimes, we study the characteristic Cauchy problem for Dirac fields on a light-cone. We prove the existence and uniqueness of solutions in the future of the light-cone inside a geodesically convex neighbourhood of the vertex. This is done for data in $L^2$ and we give an explicit definition of the space of data on the light-cone producing a

  64. Adisorn Adulpravitchai, Alexander Blum, Werner Rodejohann

    It has recently been speculated that the solar neutrino mixing angle is connected to the golden ratio phi. Two such proposals have been made, cot theta_{12} = phi and cos theta_{12} = phi/2. We compare these Ansatze and discuss a model leading to cos theta_{12} = phi/2 based on the dihedral group D_{10}. This symmetry is a natural candidate because the angle

  65. Shaofang Hong, Guoyou Qian

    Let $k\ge 0,a\ge 1$ and $b\ge 0$ be integers. We define the arithmetic function $g_{k,a,b}$ for any positive integer $n$ by $g_{k,a,b}(n):=\frac{(b+na)(b+(n+1)a)...(b+(n+k)a)} {{\rm lcm}(b+na,b+(n+1)a,...,b+(n+k)a)}.$ Letting $a=1$ and $b=0$, then $g_{k,a,b}$ becomes the arithmetic function introduced previously by Farhi. Farhi proved that $g_{k,1,0}$ is per

  66. Atsushi Nishizawa, Atsushi Taruya, Kazuhiro Hayama, Seiji Kawamura

    In a general metric theory of gravitation in four dimensions, six polarizations of a gravitational wave are allowed: two scalar and two vector modes, in addition to two tensor modes in general relativity. Such additional polarization modes appear due to additional degrees of freedom in modified theories of gravitation or theories with extra dimensions. Thus,

  67. Jean-Pierre Serre

    The first part is expository: it explains how finite fields may be used to prove theorems on infinite fields by a reduction mod p process. The second part gives a variant of P.Smith&#39;s fixed point theorem which applies in any characteristic.

  68. Giovanni Feverati, Paul A. Pearce, Nicholas S. Witte

    We consider the physical combinatorics of critical lattice models and their associated conformal field theories arising in the continuum scaling limit. As examples, we consider A-type unitary minimal models and the level-1 sl(2) Wess-Zumino-Witten (WZW) model. The Hamiltonian of the WZW model is the $U_q(sl(2))$ invariant XXX spin chain. For simplicity, we c

  69. V. K. Dobrev

    We point out that the nontrivial central extension of the superalgebra $su(2/2)$ is related to the some not so well-known Serre relations.

  70. Jelle Hartong, Mechthild Huebscher, Tomas Ortin

    In this paper we construct the supersymmetric tensor hierarchy of N=1, d=4 supergravity. We find some differences with the general bosonic construction of 4-dimensional gauged supergravities. The global symmetry group of N=1,d=4 supergravity consists of three factors: the scalar manifold isometry group, the invariance group of the complex vector kinetic matr

  71. Peter Boden, Phil Rees

    International migration is now a significant driver of population change across Europe but the methods available to estimate its true impact upon sub-national areas remain inconsistent, constrained by inadequate systems of measurement and data capture. In the absence of a population register for England, official statistics on immigration and emigration are

  72. Priscilla Canizares, Carlos F. Sopuerta

    The description of the inspiral of a stellar-mass compact object into a massive black hole sitting at a galactic centre is a problem of major relevance for the future space-based gravitational-wave observatory LISA (Laser Interferometer Space Antenna), as the signals from these systems will be buried in the data stream and accurate gravitational-wave templat

  73. Bianca M. Poggianti, Giovanni Fasano, Daniela Bettoni, Antonio Cava

    We quantify the evolution of the spiral, S0 and elliptical fractions in galaxy clusters as a function of cluster velocity dispersion ($\sigma$) and X-ray luminosity ($L_X$) using a new database of 72 nearby clusters from the WIde-Field Nearby Galaxy-cluster Survey (WINGS) combined with literature data at $z=0.5-1.2$. Most WINGS clusters have $\sigma$ between

  74. El Houcein El Abdalaoui, Mariusz Lemanczyk

    Exploiting a spectral criterion for a system not to be AT we give some new examples of zero entropy systems without the AT property. Our examples include those with finite spectral multiplicity -- in particular we show that the system arising from the Rudin-Shapiro substitution is not AT. We also show that some nil-rotations on a quotient of the Heisenberg g

  75. Ibrar Hussain, F. M. Mahomed, Asghar Qadir

    Since gravitational wave spacetimes are time-varying vacuum solutions of Einstein&#39;s field equations, there is no unambiguous means to define their energy content. However, Weber and Wheeler had demonstrated that they do impart energy to test particles. There have been various proposals to define the energy content but they have not met with great success

  76. Tom S. Mountford, K. Ravishankar, Ellen Saada

    We extend the strong macroscopic stability introduced in Bramson & Mountford (2002) for one-dimensional asymmetric exclusion processes with finite range to a large class of one-dimensional conservative attractive models (including misanthrope process) for which we relax the requirement of finite range kernels. A key motivation is extension of constructive hy

  77. P. Mitra

    The complex mass term of a quark does not violate time-reversal or parity in gravitational interactions, in spite of an axial anomaly.

  78. Alexander Elgart, Martin Tautenhahn, Ivan Veselić

    One of the fundamental results in the theory of localization for discrete Schrödinger operators with random potentials is the exponential decay of Green&#39;s function and the absence of continuous spectrum. In this paper we provide a new variant of these results for one-dimensional alloy-type potentials with finitely supported sign-changing single-site pote

  79. Paul Cardenas-Lizana, Pai-Yi Hsiao

    Using Langevin dynamics simulations, we study elastic response of single semiflexible polyelectrolytes to an external force pulling on the chain ends, to mimic the stretching of DNA molecules by optical tweezers. The linear chains are condensed by multivalent counterions into toroids. The force-extension curve shows a series of sawtooth-like structure, known

  80. Tohru Okamoto, Kohei Sasaki, Kiyohiko Toyama, Ryuichi Masutomi

    We study magnetotransport in a high mobility Si two-dimensional electron system by in situ tilting of the sample relative to the magnetic field. A pronounced dip in the longitudinal resistivity is observed during the Landau level crossing process for noninteger filling factors. Together with a Hall resistivity change which exhibits the particle-hole symmetry

  81. Anders Eriksson, Martin Nilsson Jacobi, Johan Nystrom, Kolbjorn Tunstrom

    Mesoscopic particle based fluid models, such as dissipative particle dynamics, are usually assumed to be coarse-grained representations of an underlying microscopic fluid. A fundamental question is whether there exists a map from microscopic particles in these systems to the corresponding coarse-grained particles, such that the coarse-grained system has the

  82. A. P. Balachandran, B. A. Qureshi

    In previous work, starting from the Moyal plane, we formulated interacting theories of matter and gauge fields with only the former fields twisted. In this approach, gauge theories, including the standard model, can be formulated without new gauge degrees of freedom. We show their underlying symmetry algebra to be Poincaré quasi-Hopf . The associated spaceti

  83. Michael Farber, Jean-Claude Hausmann, Dirk Schuetz

    We prove that the spaces of chains in $\bbr^d$ for $d\geq 3$ are determined by their (${\rm mod}2$)-cohomology rings.

  84. Ho-Meoyng Choi, Chueng-Ryong Ji

    We investigate the exclusive semileptonic $B_c\to (D,η_c,B,B_s)\ellν_\ell$, $η_b\to B_c\ellν_\ell$($\ell=e,μ,τ$) decays using the light-front quark model constrained by the variational principle for the QCD motivated effective Hamiltonian. The form factors $f_+(q^2)$ and $f_-(q^2)$ are obtained from the analytic continuation method in the $q^+=0$ frame. Whil

  85. Karsten Keller, Mathieu Sinn

    In the case of ergodicity much of the structure of a one-dimensional time-discrete dynamical system is already determined by its ordinal structure. We generally discuss this phenomenon by considering the distribution of ordinal patterns, which describe the up and down in the orbits of a Borel measurable map on a subset of the real numbers. In particular, we

  86. Hai-Zhou Lu, Shun-Qing Shen

    The magnetization detection and switching of an ultrasmall Stoner nanograin in a non-local spin valve (NLSV) device is studied theoretically. With the help of the rate equations, a unified description can be presented on the same footing for the NLSV signal that reads out the magnetization, and for the switching process. The setup can be viewed as that the g

  87. Chiaki Yamaguchi

    We apply analytically Niedermayer&#39;s algorithm to the Edwards-Anderson model on random graphs with arbitary degree distributions. The results for the multicritical point on the Nishimori line are shown. The results are shown by applying a criterion for spin models on the random graphs with arbitary degree distributions. The application of Niedermayer&#39;

  88. Chiaki Yamaguchi

    We analytically show the percolation thresholds of the Fortuin-Kasteleyn cluster for the Edwards-Anderson Ising model on random graphs with arbitrary degree distributions. The results on the Nishimori line are shown. We obtain the results for the +-J model, the diluted +-J model, and the Gaussian model, by applying an extension of a criterion for the random

  89. Gideon Simpson, Marc Spiegelman, Michael I. Weinstein

    In a companion paper, equations for partially molten media were derived using two-scale homogenization theory. One advantage of homogenization is that material properties, such as permeability and viscosity, readily emerge. A caveat is that the dependence of these parameters upon the microstructure is not self-evident. In particular, one seeks to relate them

  90. Vasilis Niarchos

    We discuss the non-perturbative behavior of the U(1)_R symmetry in N=2 superconformal Chern-Simons theories coupled to matter in the (anti)fundamental and adjoint representations of the gauge group, which we take to be U(N). Inequalities constraining this behavior are obtained as consequences of spontaneous breaking of supersymmetry and Seiberg duality. This

  91. Philip Yock

    Data from the Large Electron Positron collider (LEP) at CERN on hadron production in gamma-gamma interactions exceed the predictions of the standard model by an order of magnitude at the highest observed transverse momenta in three channels. The amplitude for the process is asymptotically proportional to the sum of the squares of the charges of quarks. The d

  92. M. Freidlin, L. Koralov

    In this paper we describe the long time behavior of solutions to quasi-linear parabolic equations with a small parameter at the second order term and the long time behavior of corresponding diffusion processes.

  93. M. Freidlin, L. Koralov

    In this paper we describe the asymptotic behavior, in the exponential time scale, of solutions to quasi-linear parabolic equations with a small parameter at the second order term and the long time behavior of corresponding diffusion processes. In particular, we discuss the exit problem and metastability for the processes corresponding to quasi-linear initial

  94. Dan Solomon

    In quantum field theory, it is generally assumed that there is a lower bound to the energy, which is normally assumed to the the vacuum state. While this may be a reasonable assumption for a free field it is not necessarily the case for interacting fields. In this paper I will examine a &#34;toy&#34; model of a neutral scalar field interacting with a charged

  95. Chiu Man Ho, Yu Nakayama

    We revisit the unparticle interactions and propagators from the AdS-CFT point of view, and we show how the contact terms and their renormalization group flow appear in the context of the holographic renormalization. We study both vector unparticles and unfermions, uncovering the relevant boundary conditions and renormalization group flows.

  96. Yukihiro Ota, Masahiko Machida, Tomio Koyama, Hideki Matsumoto

    Using the functional integral method, we construct a theory of heterotic SIS Josephson junctions between single- and two-gap superconductors. The theory predicts the presence of in-phase and out-of-phase collective oscillation modes of superconducting phases. The former corresponds to the Josephson plasma mode whose frequency is drastically reduced for $\pm$

  97. Chanyoung Sung

    We prove an L^2-estimate involving Ricci curvature and a harmonic 1-form on a closed oriented Riemannian 3-manifold admitting a solution of any rescaled Seiberg-Witten equations. We also give a necessary condition to be a monopole class on some special connected sums.

  98. Jo Bovy

    The recently introduced Sommerfeld enhancement of the dark matter annihilation cross section has important implications for the detection of dark matter annihilation in subhalos in the Galactic halo. In addition to the boost to the dark matter annihilation cross section from the high densities of these subhalos with respect to the main halo, an additional bo

  99. Itzhak Tserruya

    A review is presented of dilepton and real photon measurements in relativistic heavy ion collisions over a very broad energy range from the low energies of the BEVALAC up to the highest energies available at RHIC. The dileptons cover the invariant mass range \mll = 0 - 2.5 GeV/c$^2$, i.e. the continuum at low and intermediate masses and the light vector meso

  100. Antonio Avilés, Bernardo Cascales, Vladimir Kadets, Alexander Leonov

    We study the classes of filters F on N such that the weak and strong F-convergence of sequences in l1 coincide. We study also an analogue of l1 weak sequential completeness theorem for filter convergence.