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August 2010 arXiv papers — page 47

Showing 4,6014,700 of 5,306 papers

  1. G. Costakis, D. Hadjiloucas, A. Manoussos

    Based on a question raised by N. Feldman we discuss the dynamics of tuples of upper triangular Toeplitz matrices over $\mathbb{C}$. Some open problems are posed.

  2. P. Y. Tsyba, I. I. Kulnazarov, K. K. Yerzhanov, R. Myrzakulov

    In this paper, we consider three types of k-essence. These k-essence models were presented in the parametric forms. The exact analytical solutions of the corresponding equations of motion are found. It is shown that these k-essence models for the presented solutions can give rise to cosmic acceleration.

  3. Io Kawaguchi, Kentaroh Yoshida

    We discuss a hidden symmetry of a two-dimensional sigma model on a squashed S^3. The SU(2) current can be improved so that it can be regarded as a flat connection. Then we can obtain an infinite number of conserved non-local charges and show the Yangian algebra by directly checking the Serre relation. This symmetry is also deduced from the coset structure of

  4. Stephen J. Wills

    The subordinate E-semigroups of a fixed E-semigroup are in one-to-one correspondence with local projection-valued cocycles of that semigroup. For the CCR flow we characterise these cocycles in terms of their stochastic generators, that is, in terms of the coefficient driving the quantum stochastic differential equation of Hudson-Parthasarathy type that such

  5. Giorgi Japaridze

    The present paper constructs three new systems of clarithmetic (arithmetic based on computability logic --- see http://www.cis.upenn.edu/~giorgi/cl.html): CLA8, CLA9 and CLA10. System CLA8 is shown to be sound and extensionally complete with respect to PA-provably recursive time computability. This is in the sense that an arithmetical problem A has a t-time

  6. Abhijit Bhattacharyya, Paramita Deb, Anirban Lahiri, Rajarshi Ray

    We have investigated the fluctuations and the higher order susceptibilities of quark number, isospin number, electric charge and strangeness at vanishing chemical potential for 2+1 flavor Polyakov loop extended Nambu--Jona-Lasinio model. The calculations are performed for the bound effective potential in the quark sector requiring up to eight quark interacti

  7. Jürgen Blum

    More than a decade of dedicated experimental work on the collisional physics of protoplanetary dust has brought us to a point at which the growth of dust aggregates can - for the first time - be self-consistently and reliably modelled. In this article, the emergent collision model for protoplanetery dust aggregates (Güttler et al. 2010) as well as the numeri

  8. F. Mahmoudi, S. Heinemeyer, A. Arbey, A. Bharucha

    We present the Flavour Les Houches Accord (FLHA) which specifies a unique set of conventions for flavour-related parameters and observables. The FLHA uses the generic SUSY Les Houches Accord (SLHA) file structure. It defines the relevant Standard Model masses, Wilson coefficients, decay constants, bag parameters, flavour observables, etc. The accord provides

  9. Oliver Schebaum, Volker Drewello, Alexander Auge, Günter Reiss

    Using magnetron sputtering, we have prepared Co-Fe-B/tunnel barrier/Co-Fe-B magnetic tunnel junctions with tunnel barriers consisting of alumina, magnesia, and magnesia-alumina bilayer systems. The highest tunnel magnetoresistance ratios we found were 73% for alumina and 323% for magnesia-based tunnel junctions. Additionally, tunnel junctions with a unified

  10. C. Bona, C. Bona-Casas, C. Palenzuela

    A Lagrangian density is provided, that allows to recover the Z4 evolution system from an action principle. The resulting system is then strongly hyperbolic when supplemented by gauge conditions like '1+log' or 'freezing shift', suitable for numerical evolution. The physical constraint $Z_μ= 0$ can be imposed just on the initial data. The corr

  11. Leah R. Johnson, Cheryl J. Briggs

    Individual Based Models (IBMs) and Agent Based Models (ABMs) have become widely used tools to understand complex biological systems. However, general methods of parameter inference for IBMs are not available. In this paper we show that it is possible to address this problem with a traditional likelihood-based approach, using an example of an IBM developed to

  12. Antonio Padilla, Paul M. Saffin, Shuang-Yong Zhou

    The field theory Galilean symmetry, which was introduced in the context of modified gravity, gives a neat way to construct Lorentz-covariant theories of a scalar field, such that the equations of motion contain at most second-order derivatives. Here we extend the analysis to an arbitrary number of scalars, and examine the restrictions imposed by an internal

  13. C. -L. Ho

    An interesting discovery in the last two years in the field of mathematical physics has been the exceptional $X_\ell$ Laguerre and Jacobi polynomials. Unlike the well-known classical orthogonal polynomials which start with constant terms, these new polynomials have lowest degree $\ell=1,2,...$, and yet they form complete set with respect to some positive-def

  14. Martin Bauer, Florian Goertz, Ulrich Haisch, Torsten Pfoh

    We calculate the ttbar forward-backward asymmetry, A_FB^t, in Randall-Sundrum (RS) models taking into account the dominant next-to-leading order (NLO) corrections in QCD. At Born level we include the exchange of Kaluza-Klein (KK) gluons and photons, the Z boson and its KK excitations, as well as the Higgs boson, whereas beyond the leading order (LO) we consi

  15. Jing Wang, Jing-Rong Wang, Wei Li, Guo-Zhu Liu

    The three-dimensional non-compact QED is known to exhibit weak confinement when fermions acquire a finite mass via the mechanism of dynamical chiral symmetry breaking. In this paper, we study the effect of fermion damping caused by elastic scattering on the classical potential between fermions. By calculating the vacuum polarization function that incorporate

  16. Martin Lüscher, Filippo Palombi

    The definition and computation of the topological susceptibility in non-abelian gauge theories is complicated by the presence of non-integrable short-distance singularities. Recently, alternative representations of the susceptibility were discovered, which are singularity-free and do not require renormalization. Such an expression is here studied quantitativ

  17. James McKee, Chris Smyth

    We present a general construction of Salem numbers via rational functions whose zeros and poles mostly lie on the unit circle and satisfy an interlacing condition. This extends and unifies earlier work. We then consider the "obvious" limit points of the set of Salem numbers produced by our theorems, and show that these are all Pisot numbers, in support of a

  18. Sibo Zheng, Jia-Hui Huang

    In this paper,hidden sectors of Ferrara-Zumino multiplets with contributions to soft terms coming from quantum supergravity are investigated in framework of gravity mediation. The two-point correlator of Ferrara-Zumino multiplets can be parameterized, which implies the wave function renormalizations of components fields in gravity supermultiplet can be evalu

  19. T. G. Pugh, E. Sezgin, K. S. Stelle

    We construct a family of chiral anomaly-free supergravity theories in D=6 starting from D=7 supergravity with a gauged noncompact R-symmetry, employing a Horava-Witten bulk-plus-boundary construction. The gauged noncompact R-symmetry yields a positive (de Sitter sign) D=6 scalar field potential. Classical anomaly inflow which is needed to cancel boundary-fie

  20. T. Schoen, I. D. Shkredov

    Answering a question of T. Cochrane and C. Pinner, we prove that for any ε>0, sufficiently large prime number p and an arbitrary multiplicative subgroup R of the field Z/pZ, p^ε < |R| < p^{2/3-ε} the following holds |R + R|, |R - R| > |R|^{3/2+δ}, where δ>0 depends on ε only.

  21. Bernard Pire, Kirill Semenov-Tian-Shansky, Lech Szymanowski

    We construct a spectral representation for the baron to meson transition distribution amplitudes (TDAs), i.e. matrix elements involving three quark correlators which arise in the description of baryon to meson transitions within the factorization approach to hard exclusive reactions. We generalize for these quantities the notion of double distributions intro

  22. Peter Fiebig, Geordie Williamson

    We show that, with coefficients in a field or a complete local ring k, the Braden-MacPherson algorithm computes the stalks of parity sheaves with coefficients in k. As a consequence we deduce that the Braden-MacPherson algorithm may be used to calculate the characters of tilting modules for algebraic groups and show that the p-smooth locus of (Kac-Moody) Sch

  23. Peter Prettenhofer, Benno Stein

    Cross-lingual adaptation, a special case of domain adaptation, refers to the transfer of classification knowledge between two languages. In this article we describe an extension of Structural Correspondence Learning (SCL), a recently proposed algorithm for domain adaptation, for cross-lingual adaptation. The proposed method uses unlabeled documents from both

  24. Miguel Escobedo, Federica Pezzotti, Manuel Valle

    The temporal evolution of a perturbation of the equilibrium distribution of a condensed Bose gas is investigated using the kinetic equation which describes collision between condensate and noncondensate atoms. The dynamics is studied in the low momentum limit where an analytical treatment is feasible. Explicit results are given for the behavior at large time

  25. Dapeng Zhang

    We construct a canonical noncommutative spectral triple for every oriented closed Riemannian manifold, which represents the fundamental class in the twisted K-homology of the manifold. This so-called &#34;projective spectral triple&#34; is Morita equivalent to the well-known commutative spin spectral triple provided that the manifold is spin-c. We give an ex

  26. Hanshuang Chen, Chuansheng Shen, Zhonghuai Hou, Houwen Xin

    We have studied nucleation dynamics of the Ising model in scale-free networks with degree distribution $P(k)\sim k^{-γ}$ by using forward flux sampling method, focusing on how the network topology would influence the nucleation rate and pathway. For homogeneous nucleation, the new phase clusters grow from those nodes with smaller degree, while the cluster si

  27. S. M. Badalyan, J. Fabian

    We present an exact solution to the problem of the spin edge states in the presence of equal Bychkov-Rashba and Dresselhaus spin-orbit fields in a two-dimensional electron system, restricted by a hard-wall confining potential and exposed to a perpendicular magnetic field. We find that the spectrum of the spin edge states depends critically on the orientation

  28. Evan Hohlfeld, L. Mahadevan

    Sulci are localized furrows on the surface of soft materials that form by a compression-induced instability. We unfold this instability by breaking its natural scale and translation invariance, and compute a limiting bifurcation diagram for sulcfication showing that it is a scale-free, sub-critical {\em nonlinear} instability. In contrast with classical nucl

  29. C. Y. Sun, Yu Song

    It is found that the origin agegraphic dark energy tracks the matter in the matter-dominated epoch and then the subsequent dark-energy-dominated epoch becomes impossible. It is argued that the difficulty can be removed when the interaction between the agegraphic dark energy and dark matter is considered. In the note, by discussing three different interacting

  30. K. Ishii, S. Ishihara, Y. Murakami, K. Ikeuchi

    We report a Cu K-edge resonant inelastic x-ray scattering (RIXS) study of orbital excitations in KCuF3 . By performing the polarization analysis of the scattered photons, we disclose that the excitation between the eg orbitals and the excitations from t2g to eg exhibit distinct polarization dependence. The polarization dependence of the respective excitation

  31. J. K. Dong, H. Zhang, X. Qiu, B. Y. Pan

    The interplay between magnetism and superconductivity has been a central issue in unconventional superconductors. While the dynamic magnetism could be the source of electron pairing, the static magnetism is generally believed to compete with superconductivity. In this sense, the observation of Q phase, the coupled spin-density wave order and superconductivit

  32. G. Alencar, R. R. Landim, M. O. Tahim, C. R. Muniz

    In this article we study the issue of localization of the three-form field in a Randall-Sundrum-like scenario. We simulate our membrane by kinks embedded in D=5, describing the usual case (not deformed) and new models coming from a specific deformation procedure. The gravitational background regarded includes the dilaton contribution. We show that we can onl

  33. Francesco Ciccarello

    We consider an array of coupled cavities with staggered inter-cavity couplings, where each cavity mode interacts with an atom. In contrast to large-size arrays with uniform-hopping rates where the atomic dynamics is known to be frozen in the strong-hopping regime, we show that resonant atom-field dynamics with significant energy exchange can occur in the cas

  34. D. J. Miller

    IIt is shown that a weak measurement of a quantum system produces a new state of the quantum system which depends on the prior state, as well as the (uncontrollable) measured position of the pointer variable of the weak measurement apparatus. The result imposes a constraint on hidden-variable theories which assign a different state to a quantum system than s

  35. J. L. Mohr, R. A. Johnston, P. L. Cottrell

    Site measurements were collected at Mount John University Observatory in 2005 and 2007 using a purpose-built scintillation detection and ranging system. $C_n^2(h)$ profiling indicates a weak layer located at 12 - 14 km above sea level and strong low altitude turbulence extending up to 5 km. During calm weather conditions, an additional layer was detected at

  36. Wendy Baratta

    The branching coefficients in the expansion of the elementary symmetric function multiplied by a symmetric Macdonald polynomial $P_κ(z)$ are known explicitly. These formulas generalise the known $r=1$ case of the Pieri-type formulas for the nonsymmetric Macdonald polynomials $E_η(z)$. In this paper we extend beyond the case $r=1$ for the nonsymmetric Macdona

  37. Daniel Halpern-Leistner

    We use Morse theory to prove that the Lefschetz Hyperplane Theorem holds for compact smooth Deligne-Mumford stacks over the site of complex manifolds. For $Z \subset X$ a hyperplane section, $X$ can be obtained from $Z$ by a sequence of deformation retracts and attachments of high-dimensional finite disc quotients. We use this to derive more familiar stateme

  38. Jessica T. Dempsey, Per Friberg, Tim Jenness, Dan Bintley

    Commissioning of SCUBA-2 included a program of skydips and observations of calibration sources intended to be folded into regular observing as standard methods of source flux calibration and to monitor the atmospheric opacity and stability. During commissioning, it was found that these methods could also be utilised to characterise the fundamental instrument

  39. X. Q. Huang

    Intensive experiments have revealed that the superconductivity of the hole-doped cuprates can be strongly suppressed at the so-called magic doping fractions. Despite great research efforts, the origin of the `magic doping&#39; remains mysterious. Recently, we have developed a real-space theory of high-temperature superconductivity which reveals the intrinsic

  40. by Bradley Currey, Azita Mayeli

    In this work we introduce a class of discrete groups containing subgroups of abstract translations and dilations, respectively. A variety of wavelet systems can appear as $π(\G)ψ$, where $π$ is a unitary representation of a wavelet group and $\G$ is the abstract pseudo-lattice $\G$. We prove a condition in order that a Parseval frame $π(\G)ψ$ can be dilated

  41. Jason N. Armstrong, R. M. Schaub, Susan Z. Hua, Harsh Deep Chopra

    Notwithstanding the discreteness of metallic constrictions, it is shown that the finite elasticity of stable, single-atom gold constrictions allows for a continuous and reversible change in conductance, thereby enabling observation of channel saturation and conductance quantization. The observed channel saturation and signature for conductance quantization i

  42. Erik Guentner, Romain Tessera, Guoliang Yu

    We introduce a geometric invariant, called finite decomposition complexity (FDC), to study topological rigidity of manifolds. We prove for instance that if the fundamental group of a compact aspherical manifold M has FDC, and if N is homotopy equivalent to M, then M x R^n is homeomorphic to N x R^n, for n large enough. This statement is known as the stable B

  43. Andrew J. Bernoff, Chad M. Topaz

    We study equilibrium configurations of swarming biological organisms subject to exogenous and pairwise endogenous forces. Beginning with a discrete dynamical model, we derive a variational description of the corresponding continuum population density. Equilibrium solutions are extrema of an energy functional, and satisfy a Fredholm integral equation. We find

  44. Daniel R. Rohr, Julien Toulouse, Katarzyna Pernal

    We combine density-functional theory with density-matrix functional theory to get the best of both worlds. This is achieved by range separation of the electronic interaction which permits to rigorously combine a short-range density functional with a long-range density-matrix functional. The short-range density functional is approximated by the short-range ve

  45. Petr Sulc, Konstantin Turitsyn, Scott Backhaus, Michael Chertkov

    High penetration levels of distributed photovoltaic(PV) generation on an electrical distribution circuit present several challenges and opportunities for distribution utilities. Rapidly varying irradiance conditions may cause voltage sags and swells that cannot be compensated by slowly responding utility equipment resulting in a degradation of power quality.

  46. Dovi Poznanski, Peter E. Nugent, Alexei V. Filippenko

    We revisit the observed correlation between Hbeta and FeII velocities for Type II-P supernovae (SNe~II-P) using 28 optical spectra of 13 SNe II-P and demonstrate that it is well modeled by a linear relation with a dispersion of about 300 km/s. Using this correlation, we reanalyze the publicly available sample of SNe II-P compiled by D&#39;Andrea et al. and f

  47. Khalil Jaouiche

    This paper was presented at the Colloque de Saint-Denis de la Reunion, November 3-7, 1997, and published in the book L&#39;Océan Indien au carrefour des mathématiques arabes, chinoises, européennes et indiennes (pp. 211-223), Tournès, Dominique (ed.), Saint-Denis, Réunion, I.U.F.M. de La Réunion, 1998. The article is an introductory survey of the in?uence of

  48. Markus J. Aschwanden

    Nonlinear dissipative systems in the state of self-organized criticality release energy sporadically in avalanches of all sizes, such as in earthquakes, auroral substorms, solar and stellar flares, soft gamma-ray repeaters, and pulsar glitches. The statistical occurrence frequency distributions of event energies $E$ generally exhibit a powerlaw-like function

  49. Adam Rej, Fabian Spill

    In this paper we study Yangians of sl(n|m) superalgebras. We derive the universal R-matrix and evaluate it on the fundamental representation obtaining the standard Yang R-matrix with unitary dressing factors. For m=0, we directly recover up to a CDD factor the well-known S-matrices for relativistic integrable models with su(N) symmetry. Hence, the universal

  50. Cara Battersby, John Bally, James M. Jackson, Adam Ginsburg

    We examine the physical properties and evolutionary stages of a sample of 17 clumps within 8 Infrared Dark Clouds (IRDCs) by combining existing infrared, millimeter, and radio data with new Bolocam Galactic Plane Survey (BGPS) 1.1 mm data, VLA radio continuum data, and HHT dense gas (HCO+ and N2H+) spectroscopic data. We combine literature studies of star fo

  51. Eric Greenwood, De-Chang Dai, Dejan Stojkovic

    We study the evolution of time-dependent fluctuations and particle production in an expanding dS and contracting AdS universe. Using the functional Schrodinger formalism we are able to probe the time dependent regime which is out of the reach of the standard approximations like the Bogolyubov method. In both cases, the evolution of fluctuations is governed b

  52. Barbara Ercolano, Cathie J. Clarke, Alex C. Hall

    We have undertaken SED modeling of discs around low mass T Tauri stars in order to delineate regions of the infrared two colour plane (K - [8] versus K - [24]) that correspond to discs in different evolutionary stages. This provides a ready tool for classifying the nature of star-disc systems based on infrared photometry. In particular we demonstrate the dis

  53. A. T. Rezakhani, A. K. Pimachev, D. A. Lidar

    Adiabatic quantum algorithms are characterized by their run time and accuracy. The relation between the two is essential for quantifying adiabatic algorithmic performance, yet is often poorly understood. We study the dynamics of a continuous time, adiabatic quantum search algorithm, and find rigorous results relating the accuracy and the run time. Proceeding

  54. E. H. Hwang, Rajdeep Sensarma, S. Das Sarma

    Collective excitations of coupled electron-phonon systems are calculated for both monolayer and bilayer graphene, taking into account the non-perturbative Coulomb coupling between electronic excitations in graphene and the substrate longitudinal optical phonon modes. We find that the plasmon-phonon coupling in monolayer graphene is strong at all densities, b

  55. Tomotsugu Goto, Stephane Arnouts, Hanae Inami, Hideo Matsuhara

    Infrared (IR) luminosity is fundamental to understanding the cosmic star formation history and AGN evolution. The AKARI IR space telescope performed all sky survey in 6 IR bands (9, 18, 65, 90, 140, and 160um) with 3-10 times better sensitivity than IRAS, covering the crucial far-IR wavelengths across the peak of the dust emission. Combined with a better spa

  56. Leonard Burtscher, Klaus Meisenheimer, Walter Jaffe, Konrad R. W. Tristram

    We have observed Centaurus A with the MID-infrared Interferometric instrument (MIDI) at the Very Large Telescope Interferometer (VLTI) at resolutions of 7 - 15 mas (at 12.5 micron) and filled gaps in the (u,v) coverage in comparison to earlier measurements. We are now able to describe the nuclear emission in terms of geometric components and derive their par

  57. Yousuke Utsumi, Tomotsugu Goto, Nobunari Kashikawa, Satoshi Miyazaki

    QSOs have been thought to be important for tracing highly biased regions in the early universe, from which the present-day massive galaxies and galaxy clusters formed. While overdensities of star-forming galaxies have been found around QSOs at 2<z<5, the case for excess galaxy clustering around QSOs at z>6 is less clear. Previous studies with HST have report

  58. G. Dumas, E. Schinnerer, C. G. Mundell

    We present the first spatially resolved spectroscopic imaging observations of the 12CO(1-0) line emission in the central 2.5 kpc of the Seyfert 1 galaxy NGC4151, obtained with the IRAM Plateau de Bure Interferometer (PdBI). Most of the cold molecular gas is distributed along two curved gas lanes about 1 kpc north and south of the active nucleus, coincident w

  59. Charles D. Dermer

    Fermi LAT (Large Area Telescope) and GBM (Gamma ray Burst Monitor) observations of GRBs are briefly reviewed, keeping in mind EGRET expectations. Using gammaγconstraints on outflow Lorentz factors, leptonic models are pitted against hadronic models, and found to be energetically favored. Interpretation of the Fermi data on GRBs helps establish whether GRBs a

  60. Richard N. Boyd, Carl R. Brune, George M. Fuller, Christel J. Smith

    We discuss nuclear reactions which could play a role in Big Bang Nucleosynthesis (BBN). Most of these reactions involve lithium and beryllium isotopes and the rates for some of these have not previously been included in BBN calculations. Few of these reactions are well studied in the laboratory. We also discuss novel effects in these reactions, including the

  61. Jean-François Clément, Véronique Zehnlé, Jean Claude Garreau, Pascal Szriftgiser

    We propose what we believe to be a novel type of optical source for ultra-cold atomic Far Off-Resonance optical-dipole Traps (FORTs). The source is based on an Erbium Amplified Spontaneous Emission (ASE) source that seeds a high power Erbium Doped Fiber Amplifier (EDFA). The main interest of this source is its very low coherence length, thus allowing an inco

  62. Olivier Pinel, Julien Fade, Nicolas Treps, Claude Fabre

    Multimode Gaussian quantum light, including multimode squeezed and/or multipartite quadrature entangled light, is a very general and powerful quantum resource with promising applications to quantum information processing and metrology involving continuous variables. In this paper, we determine the ultimate sensitivity in the estimation of any parameter when

  63. Yang Lu, Nick Coish, Rainer Kaltenbaek, Deny R. Hamel

    Strategies to optimally discriminate between quantum states are critical in quantum technologies. We present an experimental demonstration of minimum error discrimination between entangled states, encoded in the polarization of pairs of photons. Although the optimal measurement involves projecting onto entangled states, we use a result of Walgate et al. to d

  64. Jeff Hoffstein, Alex Kontorovich

    Let pi be an automorphic representation on GL(r, A_Q) for r=1, 2, or 3. Let d be a fundamental discriminant and chi_d the corresponding quadratic Dirichlet character. We consider the question of the least d, relative to the data (level, weight or eigenvalue) of pi, such that the central value of the twisted L-series is nonzero, i.e. L(1/2, pi x chi_d) != 0.

  65. Isa Magomedov, Omar Khazamov

    The approach of applying associative processor for decision making problem was proposed. It focuses on hardware implementations of fuzzy processing systems, associativity as effective management basis of fuzzy processor. The structural approach is being developed resulting in a quite simple and compact parallel associative memory unit (PAMU). The memory cost

  66. R. Resta

    Flexoelectricity is the linear response of polarization to a strain gradient. Here we address the simplest class of dielectrics, namely elemental cubic crystals, and we prove that therein there is no extrinsic (i.e. surface) contribution to flexoelectricity in the thermodynamic limit. The flexoelectric tensor is expressed as a bulk response of the solid, man

  67. Asif Mushtaq, Amna Noreen, Kåre Olaussen, Ingjald Øverbø

    We investigate a method to solve a class of Schr{ö}dinger equation eigenvalue problems numerically to very high precision $P$ (from thousands to a million of decimals). The memory requirement, and the number of high precision algebraic operations, of the method scale essentially linearly with $P$ when only eigenvalues are computed. However, since the algorit

  68. M. A. T. van Hinsberg, J. H. M. ten Thije Boonkkamp, H. J. H. Clercx

    The hydrodynamic forces exerted by a fluid on small isolated rigid spherical particles are usually well described by the Maxey-Riley (MR) equation. The most time-consuming contribution in the MR equation is the Basset history force which is a well-known problem for many-particle simulations in turbulence. In this paper a novel numerical approach is proposed

  69. S. D. P. Vitenti, M. P. Lima, M. J. Reboucas

    The immediate observational consequence of a non-trivial spatial topology of the Universe is that an observer could potentially detect multiple images of radiating sources. In particular, a non-trivial topology will generate pairs of correlated circles of temperature fluctuations in the anisotropies maps of the cosmic microwave background (CMB), the so-calle

  70. C. Seshadhri, Jan Vondrak

    We initiate the study of property testing of submodularity on the boolean hypercube. Submodular functions come up in a variety of applications in combinatorial optimization. For a vast range of algorithms, the existence of an oracle to a submodular function is assumed. But how does one check if this oracle indeed represents a submodular function? Consider a

  71. F. D. Amaro, C. Santos, J. F. C. A. Veloso, A. Breskin

    The operation principle and preliminary results of a novel gas-avalanche patterned hole electron multiplier, the Thick-COBRA (THCOBRA), are presented. This micro-hole structure is derived from the THGEM and MHSP. Sub-millimeter diameter holes are mechanically drilled in a thin G10 plate, Cu-clad on both faces; on one of the faces the Cu is etched to produce

  72. Jimmy A. Hutasoit

    This thesis consists of two parts. The first part deals with gauge/gravity duality in the context of anti de Sitter (AdS) spacetimes with de Sitter (dS) boundary, which can be used to study issues concerning strongly coupled field theory on de Sitter space, such as the issue of vacuum ambiguity. By calculating the symmetric two point function of the strongly

  73. Michael J. Kurtz

    It is now a commonplace observation that human society is becoming a coherent super-organism, and that the information infrastructure forms its emerging brain. Perhaps, as the underlying technologies are likely to become billions of times more powerful than those we have today, we could say that we are now building the lizard brain for the future organism.

  74. Jean Bourgain, Alex Kontorovich

    In [FI09], Friedlander and Iwaniec studied the so-called Hyperbolic Prime Number Theorem, which asks for an infinitude of elements gamma in SL(2,Z) such that the norm squared |gamma|^2 = a^2 + b^2 + c^2 + d^2 = p, a prime. Under the Elliott-Halberstam conjecture, they proved the existence of such, as well as a formula for their count, off by a constant from

  75. Adrian Paschke, Alexander Kozlenkov, Harold Boley

    Event-driven automation of reactive functionalities for complex event processing is an urgent need in today&#39;s distributed service-oriented architectures and Web-based event-driven environments. An important problem to be addressed is how to correctly and efficiently capture and process the event-based behavioral, reactive logic embodied in reaction rules

  76. Ye-Lin Ou, Sheng Lu

    Biharmonic maps between surfaces are studied in this paper. We compute the bitension field of a map between surfaces with conformal metrics in complex coordinates. As applications, we show that a linear map from Euclidean plane into $(\mathbb{R}^2, σ^2dwd\bar w)$ is always biharmonic if the conformal factor $σ$ is bi-analytic; we construct a family of such $

  77. Chris Preston

    A well-known result of Bill Parry shows that a topologically transitive continuous piecewise monotone mapping with positive topological entropy is conjugate to a uniformly piecewise linear mapping with slope determined by the entropy. In this note we generalise Parry&#39;s result somewhat to what we call the class of essentially transitive mappings. This gen

  78. David V. Foster, Peter Grassberger

    We correct claims about lower bounds on mutual information (MI) between real-valued random variables made in A. Kraskov {\it et al.}, Phys. Rev. E {\bf 69}, 066138 (2004). We show that non-trivial lower bounds on MI in terms of linear correlations depend on the marginal (single variable) distributions. This is so in spite of the invariance of MI under repara

  79. Juan Souto

    Being a maximal compact subgroup of SL_nC, SU_n is a deformation retract of the former group. In this note we prove that, for sufficiently large n, there is no retraction of SL_nC to SU_n which preserves commutativity.

  80. Tetsu Mizumachi, Nikolay Tzvetkov

    We prove the nonlinear stability of the KdV solitary waves considered as solutions of the KP-II equation, with respect to periodic transverse perturbations.

  81. Christopher Bradley

    Let ABC be a triangle with P on AB, and let circle APC meet BC at Q and circle BPC meet CA at R, then the special Miquel configuration is when P, Q, R are the operative points on the sides. We show that in this case if S is the Miquel point then ASQ and BSR are straight lines. In the last part we investigate the direct similarity between ABC and DEF the tria

  82. Alexandra Shlapentokh

    We survey the recent developments in the area that grew out of attempts to extend an analog of Hilbert&#39;s Tenth Problem to the field of rational numbers and rings of integers of number fields. The paper is based on a plenary talk the author gave at the North American Annual ASL meeting at the University of Notre Dame in May of 2009.

  83. Matthew Davenport, Ken D. Olum

    &#34;Boltzmann brains&#34; are human brains that arise as thermal or quantum fluctuations and last at least long enough to think a few thoughts. In many scenarios involving universes of infinite size or duration, Boltzmann brains are infinitely more common than human beings who arise in the ordinary way. Thus we should expect to be Boltzmann brains, in contr

  84. Minh-Binh Tran

    We introduce in this paper a new tool to prove the convergence of the Overlapping Optimized Schwarz Methods with multisubdomains. The technique is based on some estimates of the errors on the boundaries of the overlapping strips. Our guiding example is an n-Dimensional Linear Parabolic Equation.

  85. R. Buta, K. Sheth, M. Regan, J. Hinz

    Spitzer Space Telescope Infrared Array Camera (IRAC) imaging provides an opportunity to study all known morphological types of galaxies in the mid-IR at a depth significantly better than ground-based near-infrared and optical images. The goal of this study is to examine the imprint of the de Vaucouleurs classification volume in the 3.6 micron band, which is

  86. M. V. Movshev

    We put on a rigorous basis results of Aisaka and Aldo Arroyo on curved βγ systems on a quadric. Drinfeld&#39;s quasimaps turned to be indispensable in accurate computation of mini-BRST cohomology.

  87. Gavin Cullen, Maciej Koch-Janusz, Thomas Reiter

    In this work, the library spinney is presented, which provides an implementation of helicity spinors and related algorithms for the symbolical manipulation program Form. The package is well suited for symbolic amplitude calculations both in traditional, Feynman diagram based approaches and unitarity-based techniques.

  88. D. S. Simon, A. V. Sergienko

    We discuss a correlated two-photon imaging apparatus that is capable of producing images that are free of the effects of odd-order aberration introduced by the optical system. We show that both quantum-entangled and classically correlated light sources are capable of producing the desired spatial-aberration cancelation.

  89. N. Kaiser

    We calculate the one-photon loop radiative corrections to the neutral pion-pair photoproduction process $π^-γ\to π^-π^0π^0$. At leading order this reaction is governed by the chiral pion-pion interaction. Since the chiral $π^+π^-\toπ^0π^0$ contact-vertex depends only on the final-state invariant-mass it factors out of all photon-loop diagrams. We give analyt

  90. T. Gallardo, J. Venturini

    Using Gauss&#39; averaged equations, we compute the secular relativistic effects generated by the Sun on the argument of the perihelion and the mean anomaly of an orbit. Then we test different alternative simpler models that have been proposed to reproduce the secular relativistic effects in the orbital elements. Generally, models introduce artificial pertur

  91. A. Odrzywolek

    Novel method of calculating Nuclear Statistical Equilibrium is presented. Basic equations are carefully solved using arbitrary precision arithmetic. Special interpolation procedure is then used to retrieve all abundances using tabulated results for neutrons and protons, together with basic nuclear data. Proton and neutron abundance tables, basic nuclear data

  92. James D. Phillips, Bijunath R. Patla, Eugeniu M. Popescu, Emanuele Rocco

    SR-POEM, our principle of equivalence measurement on a sounding rocket, will compare the free fall rate of two substances yielding an uncertainty of E-16 in the estimate of η. During the past two years, the design concept has matured and we have been working on the required technology, including a laser gauge that is self aligning and able to reach 0.1 pm pe

  93. Katharina Durstberger-Rennhofer, Yuji Hasegawa

    Entanglement between degrees of freedom, namely between the spin, path and (total) energy degrees of freedom, for single neutrons is exploited. We implemented a triply entangled Greenberger-Horne-Zeilinger(GHZ)-like state and coherently manipulated relative phases of two-level quantum subsystems. An inequality derived by Mermin was applied to analyze the gen

  94. Guangyu Xu, Carlos M. Torres, Yuegang Zhang, Fei Liu

    Scattering mechanisms in graphene are critical to understanding the limits of signal-to-noise-ratios of unsuspended graphene devices. Here we present the four-probe low frequency noise (1/f) characteristics in back-gated single layer graphene (SLG) and bilayer graphene (BLG) samples. Contrary to the expected noise increase with the resistance, the noise for

  95. Alexej Schelle, Thomas Wellens, Dominique Delande, Andreas Buchleitner

    We describe the transition of $N$ weakly interacting atoms into a Bose-Einstein condensate within a number-conserving quantum master equation theory. Based on the separation of time scales for condensate formation and non-condensate thermalization, we derive a master equation for the condensate subsystem in the presence of the non-condensate environment unde

  96. Kanak Saha, Yao Huan Tseng, Ronald E. Taam

    The nature of vertical heating of disk stars in the inner as well as the outer region of disk galaxies is studied. The galactic bar (which is the strongest non-axisymmetric pattern in the disk) is shown to be a potential source of vertical heating of the disk stars in the inner region. Using a nearly self-consistent high-resolution N-body simulation of disk

  97. F. C. Lombardo, F. D. Mazzitelli

    We analyze the introduction of dissipative effects in the study of the dynamical Casimir effect. We consider a toy model for an electromagnetic cavity that contains a semiconducting thin shell, which is irradiated with short laser pulses in order to produce periodic oscillations of its conductivity. The coupling between the quantum field in the cavity and th

  98. K. Zou, J. Zhu

    We employ a dual-gated geometry to control the band gap Δin bilayer graphene and study the temperature dependence of the resistance at the charge neutrality point, RNP(T), from 220 to 1.5 K. Above 5 K, RNP(T) is dominated by two thermally activated processes in different temperature regimes and exhibits exp(T3/T)^{1/3} below 5 K. We develop a simple model to

  99. Carl M. Bender, Hugh F. Jones

    The classical trajectories of a particle governed by the PT-symmetric Hamiltonian $H=p^2+x^2(ix)^ε$ ($ε\geq0$) have been studied in depth. It is known that almost all trajectories that begin at a classical turning point oscillate periodically between this turning point and the corresponding PT-symmetric turning point. It is also known that there are regions

  100. Piotr Korcyl

    We present exact expressions for the eigenvalues and eigenvectors of the d-dimensional Laplace operator in a cut Fock basis.