January 2009 arXiv papers — page 46

Peter Kramer

From the homotopy groups of two cubic spherical 3-manifolds we construct the isomorphic groups of deck transformations acting on the 3-sphere. These groups become the cyclic group of order eight and the quaternion group respectively. By reduction of representations from the orthogonal group to the identity representation of these subgroups we provide two sub

Sven Zschocke, Laszlo P. Csernai

The kinetic Freeze Out process of a pion gas through a finite layer with time-like normal is considered. The pion gas is described by a Boltzmann gas with elastic collisions among the pions. Within this model, the impact of the in-medium pion mass modification on the Freeze Out process is studied. A marginal change of the Freeze Out variables temperature and

Burhan Bakar, Ugur Tirnakli

The self-organized criticality in Ehrenfest's historical dog-flea model is analyzed by simulating the underlying stochastic process. The fluctuations around the thermal equilibrium in the model are treated as avalanches. We show that the distributions for the fluctuation length differences at subsequent time steps are in the shape of a $q$-Gaussian (the

E. T. Akhmedov, E. T. Musaev

It is well known that there is a total cancellation of the \emph{factorizable} IR divergences in unitary interacting field theories, such as QED and quantum gravity. In this note we show that such a cancellation does not happen in QED with background electric fields which can produce pairs. There is no factorization of the IR divergences.

Matti Jarvinen, Thomas A. Ryttov, Francesco Sannino

We show that models of dynamical electroweak symmetry breaking can possess an extremely rich finite temperature phase diagram. We suggest that early-universe extra electroweak phase transitions can appear in these models.

Bence Toth, Janos Kertesz, J. Doyne Farmer

We study the dynamics of the limit order book of liquid stocks after experiencing large intra-day price changes. In the data we find large variations in several microscopical measures, e.g., the volatility the bid-ask spread, the bid-ask imbalance, the number of queuing limit orders, the activity (number and volume) of limit orders placed and canceled, etc.

Thomas D. Cohen

It is shown that large Nc QCD must have a Hagedorn spectrum (i.e. a spectrum of hadron which grows exponentially with the hadrons mass) provided that certain technical assumptions concerning the applicability of perturbation theory to a certain class of correlation functions apply. The basic argument exploits the interplay of confinement and asymptotic freed

H1 Collaboration

Events with high energy isolated electrons, muons or tau leptons and missing transverse momentum are studied using the full e^\pm p data sample collected by the H1 experiment at HERA, corresponding to an integrated luminosity of 474 pb^{-1}. Within the Standard Model, events with isolated leptons and missing transverse momentum mainly originate from the prod

J. M. Landsberg, Zach Teitler

Motivated by questions arising in signal processing, computational complexity, and other areas, we study the ranks and border ranks of symmetric tensors using geometric methods. We provide improved lower bounds for the rank of a symmetric tensor (i.e., a homogeneous polynomial) obtained by considering the singularities of the hypersurface defined by the poly

Bobby Eka Gunara, Freddy Permana Zen

In this paper we address several aspects of flat Bogomolnyi-Prasad-Sommerfeld (BPS) domain walls together with their Lorentz invariant vacua of 4d N=1 supergravity coupled to a chiral multiplet. The scalar field spans a one-parameter family of 2d Kähler manifolds satisfying a Kähler-Ricci flow equation. We find that BPS equations and the scalar potential def

LIGO Scientific Collaboration, B. Abbott

We have searched for gravitational waves from coalescing low mass compact binary systems with a total mass between 2 and 35 Msun and a minimum component mass of 1 Msun using data from the first year of the fifth science run (S5) of the three LIGO detectors, operating at design sensitivity. Depending on mass, we are sensitive to coalescences as far as 150 Mpc

Johan Richard, Liuyi Pei, Marceau Limousin, Eric Jullo

Strong gravitational lensing is a unique tool to model with great accuracy the inner mass distribution of massive galaxy clusters. In particular, clusters with large Einstein radii provide a wealth of multiply imaged systems in the cluster core allowing to determine precisely the shape of the central dark matter profile. This paper presents a spectroscopic s

Björn Herrmann, Michael Klasen, Karol Kovarik

We compute the full O(alpha_s) supersymmetric (SUSY) QCD corrections for neutralino annihilation into massive quarks through gauge or Higgs bosons and squarks in the Minimal Supersymmetric Standard Model (MSSM), including the known resummation of logarithmically enhanced terms. The numerical impact of the corrections on the extraction of SUSY mass parameters

V. B. Bezerra, Nail R. Khusnutdinov

We consider the self-energy and the self-force for scalar massive and massless particles at rest in the wormhole space-time. We develop a general approach to obtain the self-force and apply it to the two specific profiles of the wormhole throat, namely, with singular and with smooth curvature. We found that the self-force changes its sign at the point where

H1 Collaboration

Inclusive non-diffractive photoproduction of rho(770)^0, K^*(892)^0 and phi(1020) mesons is investigated with the H1 detector in ep collisions at HERA. The corresponding average γp centre-of-mass energy is 210 GeV. The mesons are measured in the transverse momentum range 0.5<p_T<7 GeV and the rapidity range |y_{lab}|<1. Differential cross sections are presen

Atri Deshamukhya, Sudhakar Panda

We analyze warm tachyonic inflation, proposed in the literature, but from the viewpoint of four dimensional effective action for tachyon field on a non-BPS D3-brane. We find that consistency with observational data on density perturbation and validity of effective action requires warped compactification. The number of background branes which source the flux

P. -L. Giscard

We construct an operator for the Aharonov-Anandan phase for time independent Hamiltonians. This operator is shown to generate the motion of cyclic quantum systems through an equation of evolution involving only geometric quantities, i.e. the distance between quantum states, the geometric phase and the total length of evolution. From this equation, we derive

Theo van Uem

We study a discrete random walk on a one-dimensional finite lattice, where each state has different probabilities to move one step forward, backward, staying for a moment or being absorbed. We obtain expected number of arrivals and expected time until absorption using a new concept: Fibonacci matrices.

Anvar Hasanov, E. T. Karimov

We consider an equation $$ L_{α,β,γ} (u) \equiv u_{xx} + u_{yy} + u_{zz} + \displaystyle \frac{2α}{x}u_x + \displaystyle \frac{2β}{y}u_y + \displaystyle \frac{2γ}{z}u_z = 0 $$ in a domain ${\bf R}_3^ + \equiv {{({x,y,z}): x > 0, y > 0, z > 0}}$. Here $α,β,γ$ are constants, moreover $0 < 2α, 2β, 2γ< 1$. Main result of this paper is a construction of eight fun

Nicolas Perinet, Damir Juric, Laurette S. Tuckerman

We simulate numerically the full dynamics of Faraday waves in three dimensions for two incompressible and immiscible viscous fluids. The Navier-Stokes equations are solved using a finite-difference projection method coupled with a front-tracking method for the interface between the two fluids. The domain of calculation is periodic in the horizontal direction

Xiaohua Zhou

We phenomenologically analyze short DNA rings&#39; stability by discussing the second variation of its elastic free energy. Through expanding the perturbation functions as Fourier series, we obtain DNA rings&#39; stability condition in a general case. By reviewing the relationship between the Kirchhoff model and the worm-like road chain (WLRC) model, we inse

A. K. Chaudhuri

In the Israel-Stewart&#39;s theory of dissipative hydrodynamics, with a lattice based equation of state, where the confinement-deconfinement transition is a cross-over at $T_{co}$=196 MeV, we have analysed the STAR data on $ϕ$ meson production in Au+Au collisions at $\sqrt{s}$=200 GeV. From a simultaneous fit to $ϕ$ mesons multiplicity, mean $p_T$ and integr

Christian Corda, Giorgio Fontana, Gloria Garcia Cuadrado

In the framework of the debate on high-frequency gravitational waves (GWs), after a review of GWs in standard General Relativity, which is due for completness, the possibility of merging such a traditional analysis with the Hyperspace formalism that has been recently introduced in some papers in the literature, with the goal of a better understanding of mani

Zhi Wang, Shiping Feng

The electronic structure of cuprate superconductors is studied within the kinetic energy driven superconducting mechanism in the presence of the out-of-plane impurities. With increasing the impurity concentration, although both superconducting coherence peaks around nodal and antinodal regions are suppressed, the position of the leading-edge mid-point of the

T. Kitayama, Y. Ito, Y. Okada, H. Kaneda

We have undertaken a search for the infrared emission from the intracluster dust in the Coma cluster of galaxies by the Multiband Imaging Photometer for Spitzer. Our observations yield the deepest mid and far-infrared images of a galaxy cluster ever achieved. In each of the three bands, we have not detected a signature of the central excess component in cont

C. Forssén, E. Caurier, P. Navrátil

Recently, charge radii and ground-state electromagnetic moments of Li and Be isotopes were measured precisely. We have performed large-scale ab initio no-core shell model calculations for these isotopes using high-precision nucleon-nucleon potentials. The isotopic trends of our computed charge radii and quadrupole and magnetic-dipole moments are in good agre

A. C. Barato, J. A. Bonachela, C. E. Fiore, H. Hinrichsen

We study in further detail particle models displaying a boundary-induced absorbing state phase transition [Phys. Rev. E. {\bf 65}, 046104 (2002) and Phys. Rev. Lett. {\bf 100}, 165701 (2008)] . These are one-dimensional systems consisting of a single site (the boundary) where creation and annihilation of particles occur and a bulk where particles move diffus

H. Osborn, D. E. Twigg

Equations related to the Polchinski version of the exact renormalisation group equations for scalar fields which extend the local potential approximation to first order in a derivative expansion, and which maintain reparameterisation invariance, are postulated. Reparameterisation invariance ensures that the equations determine the anomalous dimension eta una

Ivan Agullo, Jose Navarro-Salas, Gonzalo J. Olmo, Leonard Parker

We point out that if quantum field renormalization is taken into account, and the counterterms are evaluated at the Hubble-radius crossing time or few e-foldings after it, the predictions of slow-roll inflation for both the scalar and tensorial power spectrum change significantly. This leads to a change in the consistency condition that relates the tensor-to

Nicolas Jacon, Cédric Lecouvey

We first describe how the Kashiwara involution on crystals of affine type $A$ is encoded by the combinatorics of aperiodic multisegments. This yields a simple relation between this involution and the Zelevinsky involution on the set of simple modules for the affine Hecke algebras. We then give efficient procedures for computing these involutions. Remarkably,

Arthur Bartels, Wolfgang Lueck

We prove the Borel Conjecture for a class of groups containing word-hyperbolic groups and groups acting properly, isometrically and cocompactly on a finite dimensional CAT(0)-space.

P. Hajicek

In a previous paper, a project of constructing quantum models of classical properties has been started. The present paper concludes the project by turning to classical mechanics. The quantum states that maximize entropy for given averages and variances of coordinates and momenta are called ME packets. They generalize the Gaussian wave packets. A non-trivial

Nabamita Banerjee, Ipsita Mandal, Ashoke Sen

Macroscopic entropy of an extremal black hole is expected to be determined completely by its near horizon geometry. Thus two black holes with identical near horizon geometries should have identical macroscopic entropy, and the expected equality between macroscopic and microscopic entropies will then imply that they have identical degeneracies of microstates.

A. Banerjee, R. Rawat, K. Mukherjee, P. Chaddah

We show that specific heat C$_p$ has non-Debye behavior for glassy states in half-doped manganites. Irrespective of the magnetic order or electronic states, these magnetic glasses have higher C$_p$ compared to their equilibrium counterparts. The excess C$_p$ contributed by the glassy state varies linearly with temperature similar to conventional glasses indi

Dong Zhang, Z. G. Dai

Newborn neutron stars surrounded by hyperaccreting and neutrino-cooled disks may exist in some gamma-ray bursts (GRBs) and/or supernovae (SNe). In this paper we further study the structure of such a neutron-star disk based on the two-region (i.e., inner & outer) disk scenario following our previous work, and calculate the neutrino annihilation luminosity fro

Gui-Jun Ding, Jia-Feng Liu, Mu-Lin Yan

We extend the one pion exchange model at quark level to include the short distance contributions coming from $η$, $σ$, $ρ$ and $ω$ exchange. This formalism is applied to discuss the possible molecular states of $D\bar{D}^{*}/\bar{D}D^{*}$, $B\bar{B}^{*}/\bar{B}B^{*}$, $DD^{*}$, $BB^{*}$, the pseudoscalar-vector systems with $C=B=1$ and $C=-B=1$ respectively.

Jonathan Andreasen, Hui Cao

A numerical model based on the finite-difference time-domain method is developed to simulate fluctuations which accompany the dephasing of atomic polarization and the decay of excited state&#39;s population. This model is based on the Maxwell-Bloch equations with c-number stochastic noise terms. We successfully apply our method to a numerical simulation of t

Jun-Jin Peng, Shuang-Qing Wu

We extend the method of Kerr/CFT correspondence recently proposed in arXiv:0809.4266 [hep-th] to the extremal (charged) Kerr black hole embedded in the five-dimensional Gödel universe. With the aid of the central charges in the Virasoro algebra and the Frolov-Thorne temperatures, together with the use of the Cardy formula, we have obtained the microscopic en

Seoktae Koh, Bin Hu

We study the dynamics of a timelike vector field which violates Lorentz invariance when the background spacetime is in an accelerating phase in the early universe. It is shown that a timelike vector field is difficult to realize an inflationary phase, so we investigate the evolution of a vector field within a scalar field driven inflation model. And we calcu

Jacob Jordan, Roman Orus, Guifre Vidal

We present a study of the hard-core Bose-Hubbard model at zero temperature on an infinite square lattice using the infinite Projected Entangled Pair State algorithm [Jordan et al., Phys. Rev. Lett. 101, 250602 (2008)]. Throughout the whole phase diagram our values for the ground state energy, particle density and condensate fraction accurately reproduce thos

Bobby E. Gunara, Freddy P. Zen, Arianto

This paper provides a study of some aspects of flat and curved BPS domain walls together with their Lorentz invariant vacua of four dimensional chiral N=1 supergravity. The scalar manifold can be viewed as a one-parameter family of Kähler manifolds generated by a Kähler-Ricci flow equation. Consequently, a vacuum manifold characterized by $(m,λ)$ where $m$ a

Dan Solomon

In quantum field theory it is generally known that the energy density may be negative at a given point in spacetime. A number of papers have shown that there is a restriction on this energy density which is called a quantum inequality (QI). A QI is the lower bound to the &#34;weighted average&#34; of the energy density at a given point integrated over a time

Ying-Qiu Gu

In this paper, we discuss some subtle concepts, such as coordinate, measurement, simultaneity, Lorentz-FitzGerald contraction, singularity in fundamental physics. The explanations of these concepts in textbooks are usually incomplete and lead to puzzles. Some long-standing paradoxes such as the Ehrenfest one are caused by misinterpretation of these concepts.

Benjamin I. Zwiebel

Bethe ansatz equations have been proposed for the asymptotic spectral problem of AdS_4/CFT_3. This proposal assumes integrability, but the previous verification of weak-coupling integrability covered only the su(4) sector of the ABJM gauge theory. Here we derive the complete planar two-loop dilatation generator of N=6 superconformal Chern-Simons theory from

Keiko Kawamuro, Elena Pavelescu

We find a self-linking number formula for a given null-homologous transverse link in a contact manifold that is compatible with either an annulus or a pair of pants open book decomposition. It extends Bennequin&#39;s self-linking formula for a braid in the standard contact $3$-sphere.

Zubeyir Cinkir

This paper concerns the tau constant, which is an important invariant of a metrized graph, and which has applications to arithmetic properties of curves. We give several formulas for the tau constant, and show how it changes under graph operations including deletion of an edge, contraction of an edge, and union of graphs along one or two points. We show how

Osamu Fujino

We obtain a correct generalization of Shokurov&#39;s non-vanishing theorem for log canonical pairs. It implies the base point free theorem for log canonical pairs. We also prove the rationality theorem for log canonical pairs. As a corollary, we obtain the cone theorem for log canonical pairs. We do not need Ambro&#39;s theory of quasi-log varieties.

Renat Zhdanov

We develop efficient group-theoretical approach to the problem of classification of evolution equations that admit non-local transformation groups (quasi-local symmetries), i.e., groups involving integrals of the dependent variable. We classify realizations of two- and three-dimensional Lie algebras leading to equations admitting quasi-local symmetries. Fina

Jordan Horowitz, Christopher Jarzynski

Kawai, Parrondo, and Van den Broeck [Phys. Rev. Lett. 98, 080602 (2007)] have recently established a quantitative relationship between dissipated work and a microscopic, information-theoretic measure of irreversibility. We illustrate this result using the exactly solvable system of a Brownian particle in a dragged harmonic trap.

Doron Gazit

I use a microscopic calculation of the weak capture process 3He(\mu^{-},\nu_\mu)3H, to extract and constrain the weak form factors of the nucleon, particularly the induced pseudo-scalar, and the second-class currents. The induced pseudo-scalar form-factor is found to agree with the prediction of chiral perturbation theory. The constraint found on the conserv

Virgilio Rodriguez, Rudolf Mathar, Anke Schmeink

In any wireless communication environment in which a transmitter creates interference to the others, a system of non-linear equations arises. Its form (for 2 terminals) is p1=g1(p2;a1) and p2=g2(p1;a2), with p1, p2 power levels; a1, a2 quality-of-service (QoS) targets; and g1, g2 functions akin to &#34;interference functions&#34; in Yates (JSAC, 13(7):1341-1

Judd D. Bowman, Alan E. E. Rogers, Jacqueline N. Hewitt

Above redshift 6, the dominant source of neutral hydrogen in the Universe shifts from localized clumps in and around galaxies and filaments to a pervasive, diffuse component of the intergalactic medium (IGM). This transition tracks the global neutral fraction of hydrogen in the IGM and can be studied, in principle, through the redshifted 21 cm hyperfine tran

Judd D. Bowman

There are three distinct regimes in which radio observations of the redshifted 21 cm line of HI can contribute directly to cosmology in unique ways. The regimes are naturally divided by redshift, from high to low, into: inflationary physics, the Dark Ages and reionization, and galaxy evolution and Dark Energy. Each measurement presents its own set of technic

Nicola Bennert, Richard Barvainis, Christian Henkel, Robert Antonucci

We report a search for H2O megamasers in 274 SDSS type-2 AGNs (0.3 < z < 0.83), half of which can be classified as type-2 QSOs from their [OIII] 5007 luminosity, using the Robert C. Byrd Green Bank Telescope (GBT) and the Effelsberg 100-m radio telescope. Apart from the detection of the extremely luminous water vapor megamaser SDSS J080430.99+360718.1, alrea

Yuri Bahturin, Alexander Olshanskii

We study acts and modules of maximal growth over finitely generated free monoids and free associative algebras as well as free groups and free group algebras. The maximality of the growth implies some other specific properties of these acts and modules that makes them close to the free ones; at the same time, we show that being a strong &#34;infiniteness&#34

C. J. Willott, P. Delorme, C. Reyle, L. Albert

We present imaging and spectroscopic observations for six quasars at z>5.9 discovered by the Canada-France High-z Quasar Survey (CFHQS). The CFHQS contains sub-surveys with a range of flux and area combinations to sample a wide range of quasar luminosities at z~6. The new quasars have luminosities 10 to 75 times lower than the most luminous SDSS quasars at t

Brendan P. Bowler, William H. Waller, S. Thomas Megeath, Brian M. Patten

At ~ 400 pc, the Horsehead Nebula (B33) is the closest radiatively-sculpted pillar to the Sun, but the state and extent of star formation in this structure is not well understood. We present deep near-infrared (IRSF/SIRIUS JHKs) and mid-infrared (Spitzer/IRAC) observations of the Horsehead Nebula in order to characterize the star forming properties of this r

Doron Gazit, Ho-Ung Yee

We present a recent proposal of a simple prescription for including low-energy weak-interactions into the framework of holographic QCD, based on the standard AdS/CFT dictionary of double-trace deformations. This opens a new perspective on phenomenological applications of holographic QCD: calculating weak observables in the strongly coupled regime of QCD. The

A. Kogut, D. J. Fixsen, S. M. Levin, M. Limon

We use absolutely calibrated data from the ARCADE 2 flight in July 2006 to model Galactic emission at frequencies 3, 8, and 10 GHz. The spatial structure in the data is consistent with a superposition of free-free and synchrotron emission. Emission with spatial morphology traced by the Haslam 408 MHz survey has spectral index beta_synch = -2.5 +/- 0.1, with

M. Seiffert, D. J. Fixsen, A. Kogut, S. M. Levin

We use absolutely calibrated data between 3 and 90 GHz from the 2006 balloon flight of the ARCADE 2 instrument, along with previous measurements at other frequencies, to constrain models of extragalactic emission. Such emission is a combination of the Cosmic Microwave Background (CMB) monopole, Galactic foreground emission, the integrated contribution of rad

Masatoshi Imanishi

We present the results of Spitzer IRS infrared 5-35 micron low-resolution spectroscopic energy diagnostics of ultraluminous infrared galaxies (ULIRGs) at z > 0.15, classified optically as non-Seyferts. Based on the equivalent widths of polycyclic aromatic hydrocarbon emission and the optical depths of silicate dust absorption features, we searched for signat

J. X. Prochaska, Y. Sheffer, D. A. Perley, J. S. Bloom

We report on strong H2 and CO absorption from gas within the host galaxy of gamma-ray burst (GRB) 080607. Analysis of our Keck/LRIS afterglow spectrum reveals a very large HI column density (NHI = 10^22.70 cm^-2) and strong metal-line absorption at z_GRB = 3.0363 with a roughly solar metallicity. We detect a series of A-X bandheads from CO and estimate N(CO)

D. J. Fixsen, A. Kogut, S. Levin, M. Limon

The ARCADE 2 instrument has measured the absolute temperature of the sky at frequencies 3, 8, 10, 30, and 90 GHz, using an open-aperture cryogenic instrument observing at balloon altitudes with no emissive windows between the beam-forming optics and the sky. An external blackbody calibrator provides an {\it in situ} reference. Systematic errors were greatly

D. C. B. Whittet, A. M. Cook, J. E. Chiar, Y. J. Pendleton

The properties of the ices that form in dense molecular clouds represent an important set of initial conditions in the evolution of interstellar and preplanetary matter in regions of active star formation. Of the various spectral features available for study, the bending mode of solid CO2 near 15 microns has proven to be a particularly sensitive probe of phy

Stephen Serjeant, Evanthia Hatziminaoglou

We have used far-infrared data from IRAS, ISO, SWIRE, SCUBA and MAMBO to constrain statistically the mean far-infrared luminosities of quasars. Our quasar compilation at redshifts 0<z<6.5 and I-band luminosities -20<I(AB)<-32 is the first to distinguish evolution from quasar luminosity dependence in such a study. We carefully cross-calibrate IRAS against Spi

Pieter G. van Dokkum, Ivo Labbe, Danilo Marchesini, Ryan Quadri

Deep near-infrared imaging surveys allow us to select and study distant galaxies in the rest-frame optical, and have transformed our understanding of the early Universe. As the vast majority of K- or IRAC-selected galaxies is too faint for spectroscopy, the interpretation of these surveys relies almost exclusively on photometric redshifts determined from fit

Max Spolaor, Robert N. Proctor, Duncan A. Forbes, Warrick J. Couch

We present a newly observed relation between galaxy mass and radial metallicity gradients of early-type galaxies. Our sample of 51 early-type galaxies encompasses a comprehensive mass range from dwarf to brightest cluster galaxies. The metallicity gradients are measured out to one effective radius by comparing nearly all of the Lick absorption-line indices t

Claudia del P. Lagos, Nelson D. Padilla, Sofia A. Cora

We use a combination of a cosmological N-body simulation of the concordance Lambda cold dark matter (LCDM) paradigm and a semi-analytic model of galaxy formation to investigate the spin development of central supermassive black holes (BHs) and its relation to the BH host galaxy properties. In order to compute BH spins, we use the alpha-model of Shakura & Sun

J. C. Pei, W. Nazarewicz, M. Stoitsov

Properties of strongly interacting, two-component finite Fermi systems are discussed within the recently developed coordinate-space Hartree-Fock-Bogoliubov (HFB) code {\hfbax}. Two illustrative examples are presented: (i) weakly bound deformed Mg isotopes, and (ii) spin-polarized atomic condensates in a strongly deformed harmonic trap.

Boris Doubrov, Jonathan Holland, George Sparling

A Weyl structure is a bundle over space-time, whose fiber at each space-time point is a space of maximally isotropic complex tangent planes. We develop the theory of Weyl connections for Weyl structures and show that the requirement that the connection be torsion-free fixes the Weyl connection uniquely. Further we show that to each such Weyl connection, ther

Leslie Ying, Yi Ming Zou

The Restricted Isometry Property (RIP) introduced by Candés and Tao is a fundamental property in compressed sensing theory. It says that if a sampling matrix satisfies the RIP of certain order proportional to the sparsity of the signal, then the original signal can be reconstructed even if the sampling matrix provides a sample vector which is much smaller in

Daniel Matthes, Robert J. McCann, Giuseppe Savar&#39;e

Global existence and long-time behavior of solutions to a family of nonlinear fourth order evolution equations on $R^d$ are studied. These equations constitute gradient flows for the perturbed information functionals $F[u] = 1/(2α) \int | D (u^α) |^2 dx + λ/2 \int |x|^2 u dx$ with respect to the $L^2$-Wasserstein metric. The value of $α$ ranges from $α=1/2$,

Francoise Truc

This paper is devoted to the asymptotics of eigenvalues for a Schrö-dinger operator in the case when the potential V does not tend to infinity at infinity. Such a potential is called degenerate. The point is that the set in the phase space where the associated hamiltonian is smaller than a fixed energy E may have an infinite volume, so that the Weyl formula

E. Hogan, M. R. Burleigh, F. J. Clarke

The aim of the Degenerate Objects around Degenerate Objects (DODO) survey is to search for very low mass brown dwarfs and extrasolar planets in wide orbits around white dwarfs via direct imaging. The direct detection of such companions would allow the spectroscopic investigation of objects with temperatures much lower (< 500 K) than the coolest brown dwarfs

Aaron Clauset

We test the claim by Yu et al. -- presented in Science 322, 104 (2008) -- that the degree distribution of the yeast (Saccharomyces cerevisiae) protein-interaction network is best approximated by a power law. Yu et al. consider three versions of this network. In all three cases, however, we find the most likely power-law model of the data is distinct from and

Sujit Gujar, C E Veni Madhavan

Still and multi-media images are subject to transformations for compression, steganographic embedding and digital watermarking. In a major program of activities we are engaged in the modeling, design and analysis of digital content. Statistical and pattern classification techniques should be combined with understanding of run length, transform coding techniq

Alexander Ermolitski

Using a smooth triangulation and a Riemannian metric on a compact, connected, closed manifold M of dimension n we have got that every such M can be represented as a union of a n-dimensional cell and a connected union K of some subsimplexes of the triangulation. A sufficiently small closed neighborhood of K is called a geometric black hole. Any smooth tensor

Kiyotaka Hammura, David Williams

The detection sensitivity (DS) of the commercial single-photon-receiver based on InGaAs gate-mode avalanche photodiode is estimated. Instalment of a digital-blanking-system (DBS) to reduce dark current makes the difference between DS, which is an efficiency of the detector during its open-gate/active state, and the total/overall detection efficiency (DE). By

A. V. Filatov, S. A. Smolyansky, A. V. Tarakanov

The kinetic equation of non - Markovian type for description of the vacuum creation of parton - antiparton pairs under action of a space homogeneous time - dependent chromo - electric field of the arbitrary polarization is obtained on the strict non - pertubative foundation in the framework of the oscillator representation. A comparison of the effectiveness

Tobias Koch, Amos Lapidoth

This work studies the capacity of multipath fading channels. A noncoherent channel model is considered, where neither the transmitter nor the receiver is cognizant of the realization of the path gains, but both are cognizant of their statistics. It is shown that if the delay spread is large in the sense that the variances of the path gains decay exponentiall

Dmitri A. Uzdensky

A simple Sweet--Parker-like model for the electron current layer in resistive Hall magnetohydrodynamic (MHD) reconnection is presented, with the focus on the collisionless limit. The derivation readily recovers the main results obtained recently by Malyshkin [PRL, 101, 225001 (2008)] and others, but is much quicker and more physically transparent. In particu

P. A. Curran, A. J. van der Horst, R. L. C. Starling, R. A. M. J. Wijers

The complex structure of the light curves of Swift GRBs has made their interpretation and that of the blast wave caused by the burst, more difficult than in the pre-Swift era. We aim to constrain the blast wave parameters: electron energy distribution, p, density profile of the circumburst medium, k, and the continued energy injection index, q. We do so by c

G. A. Moellenbrock, M. J. Claussen, W. M. Goss

We have used the VLBA to measure the annual parallax of the H2O masers in the star-forming region IRAS 00420+5530. This measurement yields a direct distance estimate of 2.17 +/- 0.05 kpc (<3%), which disagrees substantially with the standard kinematic distance estimate of ~4.6 kpc (according to the rotation curve of Brand and Blitz 1993), as well as most of

E. P. Gueuvoghlanian

A set of two-dimensional semi-riemannian submanifolds of flat semi-riemannian manifolds is associated to each Toda theory. The method and an example are given to Toda theories associated to real finite dimensional Lie algebras.

A. D. Erlykin, T. Sloan, A. W. Wolfendale

The variation with time from 1956-2002 of the globally averaged rate of ionization produced by cosmic rays in the atmosphere is deduced and shown to have a cyclic component of period roughly twice the 11 year solar cycle period. Long term variations in the global average surface temperature as a function of time since 1956 are found to have a similar cyclic

Michael A. Ivanov

Some new challenges for an experiment and observation, which are consequences of the model of low-energy quantum gravity by the author, are considered here. In particular, the property of asymptotic freedom of this model leads to the unexpected consequence: if a black hole arises due to a collapse of a matter with some characteristic mass of particles, its f

Marcos Calçada, José T. Lunardi, Luiz A. Manzoni

In this work we revisit the Salecker-Wigner-Peres clock formalism and show that it can be directly applied to the phenomenon of tunneling. Then we apply this formalism to the determination of the tunneling time of a non relativistic wavepacket, sharply concentrated around a tunneling energy, incident on a symmetric double barrier potential. In order to deepe

H1 Collaboration

A model--independent search for deviations from the Standard Model prediction is performed using the full $e^\pm p$ data sample collected by the H1 experiment at HERA. All event topologies involving isolated electrons, photons, muons, neutrinos and jets with transverse momenta above 20 GeV are investigated in a single analysis. Events are assigned to exclusi

Nikolaos Bournaveas, Vincent Calvez

The goal of this paper is to exhibit a critical mass phenomenon occuring in a model for cell self-organization via chemotaxis. The very well known dichotomy arising in the behavior of the macroscopic Keller-Segel system is derived at the kinetic level, being closer to microscopic features. Indeed, under the assumption of spherical symmetry, we prove that sol

D. Denisov, A. Buzdin, H. Shimahara

The crystal structure determines both the Fermi surface and pairing symmetry of the superconducting metals. It is demonstrated in the framework of the general phenomenological approach that this is of the primary importance for the determination of the structure of the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase in the magnetic field. The FFLO modulation o

M. Lucchesi, G. Privitera, M. Labardi, D. Prevosto

We investigate the dependency of electrostatic interaction forces on applied potentials in Electrostatic Force Microscopy (EFM) as well as in related local potentiometry techniques like Kelvin Probe Microscopy (KPM). The approximated expression of electrostatic interaction between two conductors, usually employed in EFM and KPM, may loose its validity when p

Bruno Goncalves, Jose J. Ramasco

We perform an analysis of the way individual users navigate in the Web. We focus primarily in the temporal patterns of they return to a given page. The return probability as a function of time as well as the distribution of time intervals between consecutive visits are measured and found to be independent of the level of activity of single users. The results

B. Holdom

We show that an explicit counting of Gribov copies can shed light on the infrared behavior of non-abelian gauge theories. A power-law growth of the number of copies suppresses gluon propagation while the distribution of copies along a gauge orbit implies an enhanced density of small eigenvalues of the Fadeev-Popov operator. Both of these phenomena are relate

Elijah Flenner, Grzegorz Szamel

We examine the anisotropy of a four-point correlation function $G_4(\vec{k},\vec{r};t)$ and it&#39;s associated structure factor $S_4(\vec{k},\vec{q};t)$ calculated using Brownian Dynamics computer simulations of a model glass forming system. These correlation functions measure the spatial correlations of the relaxation of different particles, and we examine

Changchuan Yin, Long Gao, Tie Liu, Shuguang Cui

We study the transmission capacities of two coexisting wireless networks (a primary network vs. a secondary network) that operate in the same geographic region and share the same spectrum. We define transmission capacity as the product among the density of transmissions, the transmission rate, and the successful transmission probability (1 minus the outage p

B. I. Belevtsev, N. V. Dalakova, M. G. Osmolowsky, E. Yu. Beliayev

Submicron powder of CrO$_2$ was prepared by hydrothermal synthesis method from chromium trioxide. Particles obtained were of rounded form with mean diameter about 120 nm. The powder (stabilized with thin surface layer of β-CrOOH) has been characterized by structural, X-ray and magnetic measurements. The powder (with Curie temperature about 385 K) was cold-pr

Gokhan Civan, John B. Etnyre, Paul Koprowski, Joshua M. Sabloff

Legendrian contact homology (LCH) and its associated differential graded algebra are powerful non-classical invariants of Legendrian knots. Linearization makes the LCH computationally tractable at the expense of discarding nonlinear (and noncommutative) information. To recover some of the nonlinear information while preserving computability, we introduce inv

Pascal Pernot

Bayesian Model Calibration is used to revisit the problem of scaling factor calibration for semi-empirical correction of ab initio calculations. A particular attention is devoted to uncertainty evaluation for scaling factors, and to their effect on prediction of observables involving scaled properties. We argue that linear models used for calibration of scal

Tsuyoshi Inoue, Ryo Yamazaki, Shu-ichiro Inutsuka

We examine MHD simulations of the propagation of a strong shock wave through the interstellar two-phase medium composed of small-scale cloudlets and diffuse warm neutral medium in two-dimensional geometry. The pre-shock two-phase medium is provided as a natural consequence of the thermal instability that is expected to be ubiquitous in the interstellar mediu

S. Russo, M. F. Craciun, M. Yamamoto, A. F. Morpurgo

We report a systematic study of the contact resistance present at the interface between a metal (Ti) and graphene layers of different, known thickness. By comparing devices fabricated on 11 graphene flakes we demonstrate that the contact resistance is quantitatively the same for single-, bi-, and tri-layer graphene ($\sim800 \pm 200 Ωμm$), and is in all case