January 2010 arXiv papers — page 33

Franz Peherstorfer

We give several descriptions of positive quadrature formulas which are exact for trigonometric -, respectively, Laurent polynomials of degree less or equal $n-1-m$, $0\leq m\leq n-1$. A complete and simple description is obtained with the help of orthogonal polynomials on the unit circle. In particular it is shown that the nodes polynomial can be generated b

P. Romano, L. Sidoli, P. Esposito, V. la Parola

We present the Swift observations of the supergiant fast X-ray transient (SFXT) SAX J1818.6-1703 collected during the most recent outburst, which occurred on May 6 2009. In particular, we present broad-band spectroscopic and timing analysis as well as a Swift/XRT light curve that spans more than two weeks of observations. The broad-band spectral models and l

K. Olejnik, P. Wadley, J. A Haigh, K. W. Edmonds

We demonstrate an exchange bias in (Ga,Mn)As induced by antiferromagnetic coupling to a thin overlayer of Fe. Bias fields of up to 240 Oe are observed. Using element-specific x-ray magnetic circular dichroism measurements, we distinguish a strongly exchange coupled (Ga,Mn)As interface layer in addition to the biassed bulk of the (Ga,Mn)As film. The interface

F. Marinacci, J. Binney, F. Fraternali, C. Nipoti

It is argued that galaxies like ours sustain their star formation by transferring gas from an extensive corona to the star-forming disc. The transfer is effected by the galactic fountain -- cool clouds that are shot up from the plane to kiloparsec heights above the plane. The Kelvin-Helmholtz instability strips gas from these clouds. If the pressure and the

V. V. Anashin, V. M. Aulchenko, E. M. Baldin, A. K. Barladyan

We report results of experiments performed with the KEDR detector at the VEPP-4M e+e- collider. They include precise measurement of the D0 and D+- meson masses, determination of the psi(3770) resonance parameters, and a search for narrow resonances in e+e- annihilation at center-of-mass energies between 1.85 and 3.1 GeV.

David Petrosyan, Georgios M. Nikolopoulos, P. Lambropoulos

We examine the speed and fidelity of several protocols for state or single excitation transfer in finite spin chains subject to diagonal and off-diagonal disorder. We find that, for a given chain length and maximal achievable inter-spin exchange (XY) coupling strength, the optimal static spin-coupling protocol, implementing the fastest state transfer between

Ryuichi Shindou, Ryota Nakai, Shuichi Murakami

Generic non-magnetic disorder effects onto those topological quantum critical points (TQCP), which intervene the three-dimensional topological insulator and an ordinary insulator, are investigated. We first show that, in such 3-d TQCP, any backward scattering process mediated by the chemical-potential-type impurity is always canceled by its time-reversal (T-

Ryan E. Johnson, Maxim Markevitch, Gary A. Wegner, Christine Jones

We present an analysis of a 72 ks Chandra observation of the double cluster Abell 1644 (z=0.047). The X-ray temperatures indicate the masses are M500=2.6+/-0.4 x10^{14} h^{-1} M_sun for the northern subcluster and M500=3.1+/-0.4 x10^{14} h^{-1} M_sun for the southern, main cluster. We identify a sharp edge in the radial X-ray surface brightness of the main c

P. Romano, L. Sidoli, the SFXT Gang

We review the status of our knowledge on supergiant fast X-ray transients (SFXTs), a new hot topic in multi wavelength studies of binaries. We discuss the mechanisms believed to power these transients and then highlight the unique contribution Swift is giving to this field, and how new technology complements and sometimes changes the view of things.

Mikko Kaasalainen

We show that the boundary curves (profiles) in $\R^2$ of the generalized projections of a body in $\R^3$ uniquely determine a large class of shapes, and that sparse profile data, combined with projection volume (brightness) data, can be used to reconstruct the shape and the spin state of a body. We also present an optimal strategy for the relative weighting

Michiel De Smet, Andreas Weiermann

We generalise the results by Bigorajska and Kotlarski about partitioning $α$-large sets, by extending the domain up to ordinals below $\varepsilon_ω$. These results will be very useful to give a miniaturisation of the infinite Ramsey Theorem.

Lukasz Bak, Andrzej Czarnecki

We present reformulation of Mathieu's result on representing cohomology classes of symplectic manifold with symplectically harmonic forms. We apply it to the case of foliated manifolds with transversally symplectic structure and to symplectic orbifolds. We obtain in particular that such representation is always possible for compact Kähler orbifolds.

C. Kuckein, R. Centeno, V. Martinez Pillet

Full Stokes spectropolarimetric data (in the 10830 A region) of an active region filament were obtained in July 2005 using the Tenerife Infrared Polarimeter instrument. The polarization profiles in the filament show Zeeman-like signatures. Milne-Eddington inversions were performed to infer the chromospheric magnetic field, inclination, azimuth, velocity and

V. K. Oikonomou

The Yukawa interaction sector of superstring inspired models that give superconducting strings, can be described in terms of a supersymmetric quantum mechanics algebra. We relate the Witten index of susy quantum mechanics with an index characteristic to superconducting string models.

F. Sukochev, D. Zanin

{\it We study the class of all rearrangement-invariant (=r.i.) function spaces $E$ on $[0,1]$ such that there exists $0<q<1$ for which $ \Vert \sum_{_{k=1}}^nξ_k\Vert_{E}\leq Cn^{q}$, where $\{ξ_k\}_{k\ge 1}\subset E$ is an arbitrary sequence of independent identically distributed symmetric random variables on $[0,1]$ and $C>0$ does not depend on $n$. We com

Amadeo Irigoyen

We deal with a problem of the explicit reconstruction of any holomorphic function $f$ on $\mathbb{C}^2$ from its restricions on a union of complex lines. The validity of such a reconstruction essentially depends on the mutual repartition of these lines, condition that can be analytically described. The motivation of this problem comes also from possible appl

Massimiliano Lattanzi, Giovanni Montani

We provide a new analysis of the system of partial differential equations describing the radial and vertical equilibria of the plasma in accretion disks. In particular, we show that the partial differential system can be separated once a definite, oscillatory (or hyperbolic) form for the radial dependence of the relevant physical quantities is assumed. The s

Brian P. Dolan, Richard J. Szabo

We review recent applications of equivariant dimensional reduction techniques to the construction of Yang-Mills-Higgs-Dirac theories with dynamical mass generation and exactly massless chiral fermions.

J. Hooyberghs, M. Baiesi, A. Ferrantini, E. Carlon

Test experiments of hybridization in DNA microarrays show systematic deviations from the equilibrium isotherms. We argue that these deviations are due to the presence of a partially hybridized long-lived state, which we include in a kinetic model. Experiments confirm the model predictions for the intensity vs. free energy behavior. The existence of slow rela

Stefan Dittmaier, Stefan Kallweit, Peter Uwer

We report on the calculation of the next-to-leading order QCD corrections to the production of W-boson pairs in association with a hard jet at the Tevatron and the LHC, which is an important source of background for Higgs and new-physics searches. Leptonic decays of the W bosons are included by applying an improved version of the narrow-width approximation t

F. Sukochev, D. Zanin

We characterize those elements in a fully symmetric spaces on the interval $(0,1)$ or on the semi-axis $(0,\infty)$ whose orbits are the norm-closed convex hull of their extreme points. Our results extend and complement earlier work on the same theme by Braverman and Mekler.

Juan Belmonte-Beitia, Valeriy Brazhnyi, Victor M. Perez-Garcia

Using Lie group theory we construct explicit solitary wave solutions of coupled nonlinear Schrodinger systems with spatially inhomogeneous nonlinearities. We present the general theory, use it to construct different families of explicit solutions and study their linear and dynamical stability.

Daniele Bettinelli, Ruggero Ferrari, Andrea Quadri

A consistent strategy for the subtraction of the divergences in the nonlinearly realized Electroweak Model in the loop expansion is presented. No Higgs field enters into the perturbative spectrum. The local functional equation (LFE), encoding the invariance of the SU(2) Haar measure under local left SU(2) transformations, the Slavnov-Taylor identity, require

G. E. Mitchell, A. Richter, H. A. Weidenmueller

The application of random-matrix theory (RMT) to compound-nucleus (CN) reactions is reviewed. An introduction into the basic concepts of nuclear scattering theory is followed by a survey of phenomenological approaches to CN scattering. The implementation of a random-matrix approach into scattering theory leads to a statistical theory of CN reactions. Since R

Mari Kobayashi, Sheng Yang, Merouane Debbah, Jean-Claude Belfiore

We consider a multi-cell MIMO downlink (network MIMO) where $B$ base-stations (BS) with $M$ antennas connected to a central station (CS) serve $K$ single-antenna user terminals (UT). Although many works have shown the potential benefits of network MIMO, the conclusion critically depends on the underlying assumptions such as channel state information at trans

Fabrizio Tamburini

Aims. We analyze and characterize the angular distribution of selected samples of gamma ray bursts (GRBs) from Batse and Swift data to confirm that the division in two classes of short- and long-duration GRBs correspond also to the existence of two distinct spatial populations. Methods. The angular distribution is analyzed by using multifractal analysis and

Yang-Hui He

We briefly review the recent programme to construct, systematically and algorithmically, large classes of heterotic vacua, as well as the search for the MSSM therein. Specifically, we outline the monad construction of vector bundles over complete intersection Calabi-Yau threefolds, their classification, stability, equivariant cohomology and subsequent releva

Uwe Thiele, Karin John

We discuss the usage of ratchet mechanisms to transport a continuous phase in several micro-fluidic settings. In particular, we study the transport of a dielectric liquid in a heterogeneous ratchet capacitor that is periodically switched on and off. The second system consists of drops on a solid substrate that are transported by different types of harmonic s

R. Guerrero, F. G. Aliev, R. Villar, T. Santos

Permalloy magnetic tunnel junctions. Complementary low frequency noise measurements are used to understand the conductance results. The obtained data indicate the breakdown of the Coulomb blockade for thickness of the asymmetric silicon layer exceeding 1.2Å. The crossover in the conductance, the dependence of the tunnelling magnetoresistance with the bias vo

C. Boeinghoff, E. E. Dyakonova, G. Kersting, V. A. Vatutin

Let ${Z_{n},n\geq 0} $ be a critical branching process in random environment and let $T$ be its moment of extinction. Under the annealed approach we prove, as $n\to \infty ,$ a limit theorem for the number of particles in the process at moment $n$ given $T=n+1$ and a functional limit theorem for the properly scaled process ${Z_{nt},δ\leq t\leq 1-δ} $ given $

K. J. H. Phillips, J. Sylwester, B. Sylwester, V. D. Kuznetsov

The solar X-ray continuum emission at five wavelengths between 3.495 Angstroms and 4.220 Angstroms for 19 flares in a seven-month period in 2002--2003 was observed by the RESIK crystal spectrometer on CORONAS-F. In this wavelength region, free--free and free--bound emissions have comparable fluxes. With a pulse-height analyzer having settings close to optima

Julie Greensmith, Jamie Twycross, Uwe Aickelin

Artificial immune systems, more specifically the negative selection algorithm, have previously been applied to intrusion detection. The aim of this research is to develop an intrusion detection system based on a novel concept in immunology, the Danger Theory. Dendritic Cells (DCs) are antigen presenting cells and key to the activation of the human signals fr

Alexander Sakhnovich

Weyl theory for a non-classical system depending rationally on the spectral parameter is treated. Borg-Marchenko-type uniqueness theorem is proved. The solution of the inverse problem is constructed. An application to sine-Gordon equation in laboratory coordinates is given.

Julien Marche

These notes of a course given at IRMA in April 2009 cover some aspects of the representation theory of fundamental groups of manifolds of dimension at most 3 in compact Lie groups, mainly $\su$. We give detailed examples, develop the techniques of twisted cohomology and gauge theory. We review Chern-Simons theory and describe an integrable system for the rep

L. Sidoli, P. Romano, L. Ducci, A. Paizis

We report here on the most recent results obtained on a new class of High Mass X-ray Binaries, the Supergiant Fast X-ray Transients. Since October 2007, we have been performing a monitoring campaign with Swift of four SFXTs (IGRJ17544-2916, XTEJ1739-302, IGRJ16479-4514 and the X-ray pulsar AXJ1841.0-0536) for about 1-2 ks, 2-3 times per week, allowing us to

Pierre Degond, Alexei Lozinski, Robert G. Owens

We propose a two fluid theory to model a dilute polymer solution assuming that it consists of two phases, polymer and solvent, with two distinct macroscopic velocities. The solvent phase velocity is governed by the macroscopic Navier-Stokes equations with the addition of a force term describing the interaction between the two phases. The polymer phase is des

Julie Greensmith, Uwe Aickelin

Dendritic Cells (DCs) are innate immune system cells which have the power to activate or suppress the immune system. The behaviour of human of human DCs is abstracted to form an algorithm suitable for anomaly detection. We test this algorithm on the real-time problem of port scan detection. Our results show a significant difference in artificial DC behaviour

E. Piconcelli, C. Vignali, S. Bianchi, F. Nicastro

We report results from a 50 ks XMM-Newton observation of the dust-reddened broad-line quasar FTM 0830+3759 (z=0.413) selected from the FIRST/2MASS Red Quasar survey. For this AGN, a very short 9 ks Chandra exposure had suggested a feature-rich X-ray spectrum and HST images revealed a very disturbed host galaxy morphology. Contrary to classical, optically-sel

V. A. Pletyukhov, V. I. Strazhev

Three massless limits of the Dirac-Kahler theory are considered. It is shown that the Dirac-Kahler equation for massive particles can be represented as a result of the gauge-invariant mixture (topological interaction) of the above massless fields.

Preethi B. Nair, Roberto G. Abraham

We present a catalog of detailed visual classifications for 14034 galaxies in the Sloan Digital Sky Survey (SDSS) Data Release 4 (DR4). Our sample includes nearly all spectroscopically-targeted galaxies in the redshift range 0.01<z<0.1 down to an apparent extinction-corrected limit of g<16 mag. In addition to T-Types we record the existence of bars, rings, l

Takeru K. Suzuki

We review our recent results of Alfven wave-driven winds. First, we present the result of a self-consistent 1D MHD simulations for solar winds from the photosphere to interplanetary region. Here, we emphasize the importance of the reflection of Alfven waves in the density stratified corona and solar winds. We also introduce the recent HINODE observation that

Jose Beltran Jimenez, Antonio L. Maroto

We consider a general class of vector-tensor theories of gravity and show that solutions with accelerated expansion and a future type III singularity are a common feature in these models. We also show that there are only six vector-tensor theories with the same small scales behavior as General Relativity and, in addition, only two of them can be made complet

Alejandro Daleo, Aude Gehrmann-De Ridder, Thomas Gehrmann, Gionata Luisoni

In this talk we present the extension of the antenna subtraction method to include initial states containing one hadron at NNLO. We sketch the requirements for the different necessary subtraction terms, and we explain how the antenna functions are integrated over the appropriate phase space by reducing the integrals to a small set of master integrals. Where

Radja Boughezal, Aude Gehrmann-De Ridder, Mathias Ritzmann

We discuss the extension of the antenna subtraction method to include two hadrons in the initial state (initial-initial antennae) at next-to-next-to-leading order. We sketch the construction of the subtraction terms and the required phase space transformations. We discuss the integration of the subtraction terms in detail.

Otakar Svitek

We derive the higher dimensional generalization of Penrose-Tod equation describing past horizon in Robinson-Trautman spacetimes with a cosmological constant and pure radiation. Results for D=4 dimensions are summarized. Existence of its solutions in D>4 dimensions is proved using tools for nonlinear elliptic partial differential equations.

Teodor I. Burghelea, Helmut Muenstedt

An experimental investigation of the impact of sample inhomogeneity on measurements of the linear elongational viscosity of two low-density polyethelenes is presented. A novel method of in-situ measurements of the diameter of samples under extension has recently been implemented to properly account for the sample non-uniformities during elongation. Two types

Carlos R. Arroyo, Thomas Frederiksen, Gabino Rubio-Bollinger, Marisela Velez

We study pentanedithiol molecular junctions formed by means of the break-junction technique with a scanning tunneling microscope at low temperatures. Using inelastic electron tunneling spectroscopy and first-principles calculations, the response of the junction to elastic deformation is examined. We show that this procedure makes a detailed characterization

Lai Baishun, Luo Qing

In this paper, we study asymptotic behavior of solution near 0 for a class of elliptic problem. The uniqueness of singular solution is established

Raffaella Morganti, Joanna Holt, Clive Tadhunter, Tom Oosterloo

The study of the conditions and the kinematics of the gas in the central region of AGN provides important information on the relevance of feedback effects connected to the nuclear activity. Quantifying these effects is key for constraining galaxy evolution models. Here we present a short summary of our recent efforts to study the occurrence and the impact of

S. Calchi Novati

We discuss pixel lensing observations towards M31 carried out at the Loiano telescope. We have established a fully automatic pipeline for the detection and the characterization of microlensing events. We have evaluated the efficiency of the pipeline. We have estimated the expected signal by means of a Monte Carlo simulation. As a result we select 2 microlens

Adrian Kuhn, David Erni, Oscar Nierstrasz

Software is intangible and knowledge about software systems is typically tacit. The mental model of software developers is thus an important factor in software engineering. It is our vision that developers should be able to refer to code as being &#34;up in the north&#34;, &#34;over in the west&#34;, or &#34;down-under in the south&#34;. We want to provide d

John Miritzis

Homogeneous and isotropic closed models are studied in both the Einstein and the Jordan frame of the second order gravity theory. The normal form of the dynamical system has periodic solutions for a large set of initial conditions. This implies that an initially expanding closed isotropic universe may exhibit oscillatory behavior.

R. Morganti, H. Rottgering, I. Snellen, G. Miley

Radio astronomy is entering the era of large surveys. This paper describes the plans for wide surveys with the LOw Frequency ARray (LOFAR) and their synergy with large surveys at higher frequencies (in particular in the 1-2 GHz band) that will be possible using future facilities like Apertif or ASKAP. The LOFAR Survey Key Science Project aims at conducting l

Arturo de Pablo, Fernando Quiros, Ana Rodriguez, Juan Luis Vazquez

We develop a theory of existence, uniqueness and regularity for a porous medium equation with fractional diffusion, $\frac{\partial u}{\partial t} + (-Δ)^{1/2} (|u|^{m-1}u)=0$ in $\mathbb{R}^N$, with $m>m_*=(N-1)/N$, $N\ge1$ and $f\in L^1(\mathbb{R}^N)$. An $L^1$-contraction semigroup is constructed and the continuous dependence on data and exponent is estab

Daniele Sasso

The purpose of the dynamics of moving systems is to search for the mathematical model that describes the link between the resultant applied force, that is the cause, and the speed of system that is the effect. This mathematical link provides the law of motion and from Newton forward it has been specified by an differential equation. Starting from the princip

Guodong Pang, Ward Whitt

We establish continuity of the integral representation $y(t)=x(t)+\int_0^th(y(s)) ds$, $t\ge0$, mapping a function $x$ into a function $y$ when the underlying function space $D$ is endowed with the Skorohod $M_1$ topology. We apply this integral representation with the continuous mapping theorem to establish heavy-traffic stochastic-process limits for many-s

R. Frielinghaus, I. E. Batov, M. Weides, H. Kohlstedt

We experimentally studied the Josephson supercurrent in Nb/InN-nanowire/Nb junctions. Large critical currents up to 5.7 $μ$A have been achieved, which proves the good coupling of the nanowire to the superconductor. The effect of a magnetic field perpendicular to the plane of the Josephson junction on the critical current has been studied. The observed monoto

Benoît Claudon

In this short note, we study compact Kähler surfaces whose universal cover can be realized as a quasi-projective (or quasi-Kähler) surface. In particular, we show that such a surface is a quotient of a torus if the universal cover is affine.

Stéphane Dugowson

This paper presents some basic facts about the so-called connectivity spaces. In particular, it studies the generation of connectivity structures, the existence of limits and colimits in the main categories of connectivity spaces, the closed monoidal category structure given by the so-called tensor product on integral connectivity spaces; it defines homotopy

Jie Cheng, Xiaojia Li, Zengru Di, Ying Fan

Robustness is an important property of complex networks. Up to now, there are plentiful researches focusing on the network&#39;s robustness containing error and attack tolerance of network&#39;s connectivity and the shortest path. In this paper, the error and attack tolerance of network&#39;s community structure are studies through randomly and purposely dis

Tanumay Datta, N. Srinidhi, A. Chockalingam, B. Sundar Rajan

Low-complexity near-optimal detection of large-MIMO signals has attracted recent research. Recently, we proposed a local neighborhood search algorithm, namely `reactive tabu search&#39; (RTS) algorithm, as well as a factor-graph based `belief propagation&#39; (BP) algorithm for low-complexity large-MIMO detection. The motivation for the present work arises f

Chandru Iyer, G. M. Prabhu

A formulation of the one-way speed of light in three-dimensional Euclidean space is derived by a constructive approach. This formulation is consistent with the result of the Michelson-Morley experiment in that the harmonic mean of the outward and return speeds is equal to c, the standard value for the speed of electromagnetic radiation in vacuum. It is also

Bharat K. Sharma, Subrata Pal

The liquid-gas phase transition in hot asymmetric nuclear matter is investigated within relativistic mean-field model using the density dependence of nuclear symmetry energy constrained from the measured neutron skin thickness of finite nuclei. We find symmetry energy has a significant influence on several features of liquid-gas phase transition. The boundar

V. O. Bytev

The nonclassical model of elasticity was presented

Amlan K. Roy

A recently developed density functional method, within Hohenberg-Kohn-Sham framework, is used for faithful description of atoms, molecules in Cartesian coordinate grid, by using an LCAO-MO ansatz. Classical Coulomb potential is obtained by means of a Fourier convolution technique. All two-body potentials (including exchange-correlation (XC)) are constructed

Hisatomo Harima, Kazumasa Miyake, Jacques Flouquet

For more than two decades, the nonmagnetic anomaly observed around 17.5 K in URu2Si2, has been investigated intensively. However, any kind of fingerprint for the lattice anomaly has not been observed. Therefore, the order has been called &#34;the hidden order&#34;. One simple answer to why the hidden order is still hidden is presented from the space group an

Michael J. I. Brown, the Bootes Field Collaborations

In cold dark matter cosmologies, the most massive dark matter halos are predicted to undergo rapid growth at z<1. While there is the expectation that massive galaxies will also rapidly grow via merging, recent observational studies conclude that the stellar masses of the most massive galaxies grow by just 30 percent at z<1. We have used the observed space de

Hsi-Wei Yen, Shigehisa Takakuwa, Nagayoshi Ohashi

We have performed detailed imaging and analyses of SMA observations in 230 GHz continuum, 12CO (2-1), 13CO (2-1), and C18O (2-1) emission toward B335, a Bok globule with an embedded Class 0 source (Lbol ~ 1.5 Lsun). We report the first discover of high-velocity 12CO jets with a size of ~ 900 AU x 1500 AU along the E-W direction in B335. The estimated mass-lo

Zach Medin, Dong Lai

We present numerical simulations of electron-positron pair cascades in the magnetospheres of magnetic neutron stars for a wide range of surface fields (B_p = 10^{12}--10^{15} G), rotation periods (0.1--10 s), and field geometries. This has been motivated by the discovery in recent years of a number of radio pulsars with inferred magnetic fields comparable to

Zihan Zhou, Xiaodong Li, John Wright, Emmanuel Candes

In this paper, we study the problem of recovering a low-rank matrix (the principal components) from a high-dimensional data matrix despite both small entry-wise noise and gross sparse errors. Recently, it has been shown that a convex program, named Principal Component Pursuit (PCP), can recover the low-rank matrix when the data matrix is corrupted by gross s

Eloy Ayón-Beato, Alan Garbarz, Gaston Giribet, Mokhtar Hassaïne

We generalize the four-dimensional R^2-corrected z=3/2 Lifshitz black hole to a two-parameter family of black hole solutions for any dynamical exponent z and for any dimension D. For a particular relation between the parameters, we find the first example of an extremal Lifshitz black hole. An asymptotically Lifshitz black hole with a logarithmic decay is als

S. J. Tanaka, F. Takahara

Recent observations suggest that many old pulsar wind nebulae (PWNe) are bright TeV gamma-ray sources without a strong X-ray counterpart. In this paper, we study the spectral evolution of PWNe taking into account the energy which was injected when they were young for old PWNe. We model the evolution of the magnetic field and solve for the particle distributi

Runyao Duan, Markus Grassl, Zhengfeng Ji, Bei Zeng

We construct new families of multi-error-correcting quantum codes for the amplitude damping channel. Our key observation is that, with proper encoding, two uses of the amplitude damping channel simulate a quantum erasure channel. This allows us to use concatenated codes with quantum erasure-correcting codes as outer codes for correcting multiple amplitude da

Debi Prasad Choudhary, Toshifumi Shimizu

We used the flux calibrated images through the Broad Band Filter Imager and Stokes Polarimeter data obtained with the Solar Optical Telescope onboard the Hinode spacecraft to study the properties of bright points in and around the sunspots. The well isolated bright points were selected and classified as umbral dot, peripheral umbral dot, penumbral grains and

Trinh Khanh Tuoc

This paper proposes a simple new closure principle for turbulent shear flows. The turbulent flow field is divided into an outer and an inner region. The inner region is made up of a log-law region and a wall layer. The wall layer is viewed in terms of the well known inrush-sweep-burst sequence observed since 1967. It is modelled as a transient laminar sub-bo

Chengguang Bao

A model of a device is proposed and related theoretical calculation is performed to study the weak interactions among neutral atoms and molecules. In this model 3-body collisions among the neutral particles occur repeatedly in a trap. Results of calculation demonstrate that information on interaction can be obtained by observing the time-dependent densities

H. S. Wio, J. A. Revelli, R. R. Deza, C. Escudero

In order to perform numerical simulations of the KPZ equation, in any dimensionality, a spatial discretization scheme must be prescribed. The known fact that the KPZ equation can be obtained as a result of a Hopf--Cole transformation applied to a diffusion equation (with \emph{multiplicative} noise) is shown here to strongly restrict the arbitrariness in the

Paul Bracken

The Hodge-de Rham Theorem is introduced and discussed. This result has implications for the general study of several partial differential equations. Some propositions which have applications to the proof of this theorem are used to study some related results concerning a class of partial differential equation in a novel way.

Songmei Huan, Xiao-Song Yang

Based on the results about the invariant cones appeared in the literature this paper analyses the existence of periodic orbits in three-dimensional continuous piecewise linear homogeneous systems with two zones, and a necessary and sufficient condition for the existence of periodic orbits of such systems is given.

H. Chen, X. Gong, L. He, A. Zhou

In this paper, we study an adaptive finite element method for a class of a nonlinear eigenvalue problems that may be of nonconvex energy functional and consider its applications to quantum chemistry. We prove the convergence of adaptive finite element approximations and present several numerical examples of micro-structure of matter calculations that support

Rafail V. Abramov

The recently developed short-time linear response algorithm, which predicts the average response of a nonlinear chaotic system with forcing and dissipation to small external perturbation, generally yields high precision of the response prediction, although suffers from numerical instability for long response times due to positive Lyapunov exponents. However,

Enrico Prati

I present a theoretical model of a quantum statistical ensemble for which, unlike in conventional physics, the total number of particles is extremely small. The thermodynamical quantities are calculated by taking a small $N$ by virtue of the orthodicity of canonical ensemble. The finite quantum grand partition function of a Fermi-Dirac system is calculated.

Sriram Vishwanath

This paper studies the low-rank matrix completion problem from an information theoretic perspective. The completion problem is rephrased as a communication problem of an (uncoded) low-rank matrix source over an erasure channel. The paper then uses achievability and converse arguments to present order-wise optimal bounds for the completion problem.

Muhammad Nazmul Islam, Raviraj Adve

We investigate quantization and feedback of channel state information in a multiuser (MU) multiple input multiple output (MIMO) system. Each user may receive multiple data streams. Our design minimizes the sum mean squared error (SMSE) while accounting for the imperfections in channel state information (CSI) at the transmitter. This paper makes three contrib

Mário A. T. Figueiredo, José M. Bioucas-Dias

Much research has been devoted to the problem of restoring Poissonian images, namely for medical and astronomical applications. However, the restoration of these images using state-of-the-art regularizers (such as those based on multiscale representations or total variation) is still an active research area, since the associated optimization problems are qui

Falai Chen, Xuhui Wang

In this paper we discuss the relationship between the moving planes of a rational parametric surface and the singular points on it. Firstly, the intersection multiplicity of several planar curves is introduced. Then we derive an equivalent definition for the order of a singular point on a rational parametric surface. Based on the new definition of singularit

Dennis Borisov

A club structure is defined on the category of simplicial sets. This club generalizes the operad of associative rings by adding &#34;amalgamated&#34; products.

Takuro Mochizuki

We define the notion of Betti structure for holonomic D-modules which are not necessarily regular singular. We establish the fundamental functorial properties. We also give auxiliary analysis of holomorphic functions of various types on the real blow up.

Matthew B. Hastings, Ivan Gonzalez, Ann B. Kallin, Roger G. Melko

We develop a quantum Monte Carlo procedure, in the valence bond basis, to measure the Renyi entanglement entropy of a many-body ground state as the expectation value of a unitary {\it Swap} operator acting on two copies of the system. An improved estimator involving the ratio of {\it Swap} operators for different subregions enables simulations to converge th

D. Schmeltzer

We investigate the Hubbard model in the limit $U=\infty$, which is equivalent to the statistical condition of exclusion of double occupancy. We solve this problem using Dirac&#39;s method for constraints. The constraints are solved within the Bosonization method. We find that the constraints modify the anomalous commutator. We apply this theory to quantum wi

Julien Berestycki, Nathanaël Berestycki, Jason Schweinsberg

We consider a system of particles which perform branching Brownian motion with negative drift and are killed upon reaching zero, in the near-critical regime where the total population stays roughly constant with approximately N particles. We show that the characteristic time scale for the evolution of this population is of order $(\log N)^3$, in the sense th

Gary M. Bernstein

Precision weak gravitational lensing experiments require measurements of galaxy shapes accurate to <1 part in 1000. We investigate measurement biases, noted by Voigt and Bridle (2009) and Melchior et al. (2009), that are common to shape measurement methodologies that rely upon fitting elliptical-isophote galaxy models to observed data. The first bias arises

I. I. Mazin

BiOCu_{1-y}S was recently reported to superconduct at T=5.8 K at y~0.15. Band structure calculations indicate that stoichiometric BiOCuS is a band insulator. In this paper, I show that hole-doped (whether in the virtual crystal approximation or with actual Cu vacancies) BiOCuS is on the verge of a ferromagnetic instability (cf. Pd metal), and therefore conve

Anthony Fanous, Anthony Ephremides

In this paper, we investigate the impact of network coding at the relay node on the stable throughput rate in multicasting cooperative wireless networks. The proposed protocol adopts Network-level cooperation in contrast to the traditional physical layer cooperative protocols and in addition uses random linear network coding at the relay node. The traffic is

Yeow-Khiang Chia, Abbas El Gamal

A lower bound on the secrecy capacity of the wiretap channel with state information available causally at both the encoder and decoder is established. The lower bound is shown to be strictly larger than that for the noncausal case by Liu and Chen. Achievability is proved using block Markov coding, Shannon strategy, and key generation from common state inform

X. Xu, M. White, N. Padmanabhan, D. Eisenstein

We introduce a new statistic omega_l for measuring and analyzing large-scale structure and particularly the baryon acoustic oscillations. omega_l is a band-filtered, configuration space statistic that is easily implemented and has advantages over the traditional power spectrum and correlation function estimators. Unlike these estimators, omega_l can localize

Kazuyuki Furuuchi

The derivation of the self-dual relations for the two-form gauge field in the Nambu-bracket description of M5-brane in a constant C-field background initiated in arXiv:0907.4596 is completed by including contributions from all the fields in the M5-brane action. The result is used to examine Seiberg-Witten map of the BPS conditions for the string solitons, up

Gabriel Billings, A. Douglas Stone, Y. Alhassid

We use a many-body rate-equation approach to calculate the thermopower of a quantum dot in the presence of an exchange interaction. At temperatures much smaller than the single-particle level spacing, the known quantum jumps (discontinuities) in the thermopower are split by the exchange interaction. The origin and nature of the splitting are elucidated with

Stefano Forte, Eric Laenen, Paolo Nason, Juan Rojo

We discuss a general framework for the inclusion of heavy quark mass contributions to deep-inelastic structure functions and their perturbative matching to structure functions computed in variable-mass schemes. Our approach is based on the so-called FONLL method, previously introduced and applied to heavy quark hadroproduction and photoproduction. We define

Paul H. Frampton, Masahiro Kawasaki, Fuminobu Takahashi, Tsutomu T. Yanagida

We argue that a primordial black hole is a natural and unique candidate for all dark matter. We show that, in a smooth-hybrid new double inflation model, a right amount of the primordial black holes, with a sharply-defined mass, can be produced at the end of the smooth-hybrid regime, through preheating. We first consider masses < 10^(-7)M_sun which are allow