April 2010 arXiv papers — page 21

Z. Burda, J. Duda, J. M. Luck, B. Waclaw

We review various features of the statistics of random paths on graphs. The relationship between path statistics and Quantum Mechanics (QM) leads to two canonical ways of defining random walk on a graph, which have different statistics and hence different entropies. Generic random walk (GRW) is in correspondence with the field-theoretical formalism, whereas

P. M. Hansen, J. Alvarez-Muniz, R. A. Vazquez

By means of Monte Carlo simulations of extensive air showers (EAS), we have performed a comprehensive study of the shower to shower fluctuations affecting the longitudinal and lateral development of EAS. We split the fluctuations into physical fluctuations and those induced by the thinning procedure customarily applied to simulate showers at EeV energies and

Jorge Alfaro, Domènec Espriu, Daniel Puigdomènech

We review the similarities between the effective chiral lagrangrian, relevant for low-energy strong interactions, and the Einstein-Hilbert action. We use these analogies to suggest a specific mechanism whereby gravitons would emerge as Goldstone bosons of a global SO(D) X GL(D) symmetry broken down to SO(D) by fermion condensation. We propose a two-dimension

Thomas Franosch, Sylvia Jeney

We have investigated the motion of a single optically trapped colloidal particle close to a limiting wall at time scales where the inertia of the surrounding fluid plays a significant role. The velocity autocorrelation function exhibits a complex interplay due to the momentum relaxation of the particle, the vortex diffusion in the fluid, the obstruction of f

M. Puig von Friesen, C. Verdozzi, C. -O. Almbladh

We present in detail a method we recently introduced (PRL. 103, 176404 (2009)) to describe finite systems in and out of equilibrium, where the evolution in time is performed via the Kadanoff-Baym Equations (KBE) within Many-Body Perturbation Theory (MBPT). The main property we analyze is the time-dependent density. We also study is the exchange-correlation p

Sigbjorn Hervik, Woei Chet Lim, Patrik Sandin, Claes Uggla

In this paper we study the future asymptotics of spatially homogeneous Bianchi type II cosmologies with a tilted perfect fluid with a linear equation of state. By means of Hamiltonian methods we first find a monotone function for a special tilted case, which subsequently allows us to construct a new set of monotone functions for the general tilted type II co

Gábor Erdélyi, Michael Fellows

We study the parameterized control complexity of fallback voting, a voting system that combines preference-based with approval voting. Electoral control is one of many different ways for an external agent to tamper with the outcome of an election. We show that adding and deleting candidates in fallback voting are W[2]-hard for both the constructive and destr

A. Solontsov, V. P. Antropov

We suggest a model for the magnetic dynamics of - plutonium and its alloys in order to show that the dynamical fluctuations of the magnetization density, or spin fluctuations, may be responsible for the anomalies of their observed thermal expansion. We show that due to strong magneto-elastic coupling, spin fluctuations may essentially contribute to the volum

J. Suorsa, S. Viefers, T. H. Hansson

We develop a formalism to describe quasihole condensates in quantum Hall liquids and thereby extend the conformal field theory approach to the full hierarchy of spin-polarized Abelian states, and to several classes of non-Abelian hierarchical states. Most previously proposed spin-polarized quantum Hall wave functions appear as special cases. In this paper we

Tero T. Heikkila, Moosa Hatami, Gerrit E. W. Bauer

We study the spin thermalization, i.e., the inter-spin energy relaxation mediated by electron-electron scattering in small spin valves. When one or two of the dimensions of the spin valve spacer are smaller than the thermal coherence length, the direct spin energy exchange rate diverges and needs to be regularized by the sample dimensions. Here we consider t

Yu. P. Rybakov, G. N. Shikin, Yu. A. Popov, Bijan Saha

We consider an interacting system of massless scalar and electromagnetic field, with the Lagrangian explicitly depending on the electromagnetic potentials, i.e., interaction with broken gauge invariance. The Lagrangian for interaction is chosen in such a way that the electromagnetic field equation acquires an additional term, which in some cases is proportio

I. M. Khaymovich, N. M. Chtchelkatchev, I. A. Shereshevskii, A. S. Mel'nikov

The conductance in two-dimensional (2D) normal-superconducting (NS) systems is analyzed in the limit of strong magnetic fields when the transport is mediated by the electron-hole states bound to the sample edges and NS interface, i.e., in the Integer Quantum Hall Effect regime.The Andreev-type process of the conversion of the quasiparticle current into the s

Lamei Yuan, Liji Zhou

In present paper, we quantize the extended SchrÄodinger-Virasoro Lie algebra in char- acteristic zero with its Lie bialgebra structures classified by Yuan-Wu-Xu, and get a new Hopf algebra.

S M Feng, Y S Chai, J L Zhu, N Manivannan

Whether large ferroelectric polarization P exists in the orthorhombic HoMnO3 with the E-type antiferromagnetic spin ordering or not remains as one of unresolved, challenging issues in the physics of multiferroics. The issue is closely linked to an intriguing experimental difficulty for determining P of polycrystalline specimens that conventional pyroelectric

G. Bismut, B. Pasquiou, D. Ciampini, B. Laburthe-Tolra

We report on a strategy to maximize the number of chromium atoms transferred from a magneto-optical trap into an optical trap through accumulation in metastable states via strong optical pumping. We analyse how the number of atoms in a chromium Bose Einstein condensate can be raised by a proper handling of the metastable state populations. Four laser diodes

Arvind W. Kiwelekar, Rushikesh K. Joshi

A UML based metamodel for Bunge-Wand-Weber (BWW) ontology is presented. BWW ontology is a generic framework for analysis and conceptualization of real world objects. It includes categories that can be applied to analyze and classify objects found in an information system. In the context of BWW ontology, the metamodel is a representation of the ontological ca

Péter Lévay

In this paper we describe the structure of extremal stationary spherically symmetric black hole solutions in the STU model of D=4, N=2 supergravity in terms of four-qubit systems. Our analysis extends the results of previous investigations based on three qubits. The basic idea facilitating this four-qubit interpretation is the fact that stationary solutions

Anjan S. Joshipura, Bhavik P. Kodrani

The charged fermion mass matrices are always invariant under $U(1)^3$ symmetry linked to the fermion number transformation. A class of two Higgs doublet models (2HDM) can be identified by requiring that the definition of this symmetry in an arbitrary weak basis be independent of Higgs parameters such as the ratio of the Higgs vacuum expectation values. The t

Sasa Prelovsek

Searches for tetraquarks and mesonic molecules in lattice QCD are briefly reviewed. In the light quark sector the most serious candidates are the lightest scalar resonances sigma, kappa, a0 and f0. In the hidden-charm sector I discuss lattice simulations of X(3872), Y(4260), Y(4140) and Z^+(4430). The most serious challenge in all these lattice studies is th

Tomas Masopust

This paper solves an open problem concerning the generative power of nonerasing context-free rewriting systems using a simple mechanism for checking for context dependencies, in the literature known as semi-conditional grammars of degree (1,1). In these grammars, two nonterminal symbols are attached to each context-free production, and such a production is a

Ognian Kassabov

Criterions for constancy of the holomorphic sectional curvature and the antiholomorphic sectional curvature are proved for almost Hermitian manifolds. It is shown, that an almost Hermitian manifold satisfying the axiom of antiholomorphic planes or the axiom of antiholomorphic spheres is a real or a complex space form.

Ming Jie Zheng, Yun San Chan, Kin Wah Yu

We study the optical oscillations of supermodes in planar optical waveguide arrays with parabolically graded propagation constant in individual waveguide interacting through nearest neighbor couplings. In these arrays, we have identified a transition between a symmetric dipole oscillation (DO) and a symmetry-breaking Bloch oscillation (BO) under appropriate

Matthias Hammerl, Katja Sagerschnig

Generic distributions on 5- and 6-manifolds give rise to conformal structures that were discovered by P. Nurowski resp. R. Bryant. We describe both as Fefferman-type constructions and show that for orientable distributions one obtains conformal spin structures. The resulting conformal spin geometries are then characterized by their conformal holonomy and equ

Yuya Inagaki, Jun-ichi Inoue

We numerically investigate a mean-field Bayesian approach with the assistance of the Markov chain Monte Carlo method to estimate motion velocity fields and probabilistic models simultaneously in consecutive digital images described by spatio-temporal Markov random fields. Preliminary to construction of our procedure, we find that mean-field variables in the

Kenji Bekki, Alister W. Graham

Giant elliptical galaxies, believed to be built from the merger of lesser galaxies, are known to house a massive black hole at their center rather than a compact star cluster. If low- and intermediate-mass galaxies do indeed partake in the hierarchical merger scenario, then one needs to explain why their dense nuclear star clusters are not preserved in merge

Richard P. Brent

We describe some "unrestricted" algorithms which are useful for the computation of elementary and special functions when the precision required is not known in advance. Several general classes of algorithms are identified and illustrated by examples. The topics include: power series methods, use of halving identities, asymptotic expansions, continued

Masahiro Futaki, Kazushi Ueda

We prove a conjecture on the relation between dimer models, coamoebas and vanishing cycles for the mirrors of two-dimensional toric Fano stacks of Picard number one. As a corollary, we obtain a torus-equivariant version of homological mirror symmetry for such stacks.

Matthias Aschenbrenner, Stefan Friedl

Let $f\colon M\to N$ be a continuous map between closed irreducible graph manifolds with infinite fundamental group. Perron and Shalen showed that if $f$ induces a homology equivalence on all finite covers, then $f$ is in fact homotopic to a homeomorphism. Their proof used the statement that every graph manifold is finitely covered by a $3$-manifold whose fu

Qingshuo Song, Guanrong Chen, Daniel W. C. Ho

Our goal is to find a necessary and sufficient condition on the consensus over a random network, generated by i.i.d. stochastic matrices. We show that the consensus problem in three different convergence modes (almost surely, in probability, and in L1) are equivalent, thus have the same necessary and sufficient condition. We obtain the necessary and sufficie

Christian Meyer

We propose an algorithm for evaluation of the cumulative bivariate normal distribution, building upon Marsaglia's ideas for evaluation of the cumulative univariate normal distribution. The algorithm is mathematically transparent, delivers competitive performance and can easily be extended to arbitrary precision.

Yisheng Chai, Hongshun Yang, Jian Liu, Chenghai Sun

We report thermal transport measurements performed on the quasi-one-dimensional Bechgaard salts (TMTSF)2ClO4 and (TMTSF)2PF6 along the a-direction. For both salts, magnon-drag effects are found to contribute considerably to thermopower above 80 K. These results imply spin-charge separation in the metallic state for both salts. Moreover, a linear temperature-

Masayuki Tanaka, Alexis Finoguenov, Yoshihiro Ueda

We report on a confirmed galaxy cluster at z=1.62. We discovered two concentrations of galaxies at z~1.6 in the Subaru/XMM-Newton deep field based on deep multi-band photometric data. We made a near-IR spectroscopic follow-up observation of them and confirmed several massive galaxies at z=1.62. One of the two is associated with an extended X-ray emission at

Takuya Saito, Kenichi Yoshikawa

We applied the mean-field approach to a columnar bundle assembled by the parallel arrangement of stiff polyelectrolyte rods in a salt bath. The electrostatic potential can be divided into two regions: inside the bundle for condensed counter-ions, and outside the bundle for free small ions. To determine the distribution of condensed counter-ions inside the bu

Tatyana G. Gerasimova, Roger A. Horn, Vladimir V. Sergeichuk

Docovic and Szechtman, [Proc. Amer. Math. Soc. 133 (2005) 2853-2863] considered a vector space V endowed with a bilinear form. They proved that all isometries of V over a field F of characteristic not 2 have determinant 1 if and only if V has no orthogonal summands of odd dimension (the case of characteristic 2 was also considered). Their proof is based on R

R. N. Manchester

Pulsars are very stable clocks in space which have many applications to problems in physics and astrophysics. Observations of double-neutron-star binary systems have given the first observational evidence for the existence of gravitational waves (GWs) and shown that Einstein's general theory of relativity is an accurate description of gravitational inter

Lena Klimenko, Vladimir V. Sergeichuk

For each square complex matrix, V. I. Arnold constructed a normal form with the minimal number of parameters to which a family of all matrices B that are close enough to this matrix can be reduced by similarity transformations that smoothly depend on the entries of B. Analogous normal forms were also constructed for families of complex matrix pencils by A. E

Elena Mason, Marcos Diaz, Robert E. Williams, George Preston

Nova Scorpii 2008 was the target of our Directory Discretionary Time proposal at VLT+UVES in order to study the evolution, origin and abundances of the heavy-element absorption system recently discovered in 80% of classical novae in outburst. The early decline of Nova Scorpii 2008 was monitored with high resolution echelle spectroscopy at 5 different epochs.

Evelyn Buckwar, Thorsten Sickenberger

In this article we compare the mean-square stability properties of the Theta-Maruyama and Theta-Milstein method that are used to solve stochastic differential equations. For the linear stability analysis, we propose an extension of the standard geometric Brownian motion as a test equation and consider a scalar linear test equation with several multiplicative

Akimichi Takemura, Hisayuki Hara

Markov chain models are used in various fields, such behavioral sciences or econometrics. Although the goodness of fit of the model is usually assessed by large sample approximation, it is desirable to use conditional tests if the sample size is not large. We study Markov bases for performing conditional tests of the toric homogeneous Markov chain model, whi

M. V. Simkin, V. P. Roychowdhury

Recently Osorio et al (Eur. J. Neurosci., 30 (2009) 1554) reported that probability distribution of intervals between successive epileptic seizures follows a power law with exponent 1.5. We theoretically explain this finding by modeling epileptic activity as a branching process, which we in turn approximate by a random walk. We confirm the theoretical conclu

Howard Baer, Vernon Barger, Andre Lessa, Xerxes Tata

We examine the capability of the CERN Large Hadron Collider to discovery supersymmetry (SUSY) with energy \sqrt{s}=7 TeV and integrated luminosity of about 1 fb^{-1}. Our results are presented within the paradigm minimal supergravity model (mSUGRA or CMSSM). Using a 6-dimensional grid of cuts for optimization of signal to background-- including missing E_T--

Andrii Dmytryshyn, Vyacheslav Futorny, Bo Kågström, Lena Klimenko

We construct the Hasse diagrams $G_2$ and $G_3$ for the closure ordering on the sets of congruence classes of $2\times 2$ and $3\times 3$ complex matrices. In other words, we construct two directed graphs whose vertices are $2\times 2$ or, respectively, $3\times 3$ canonical matrices under congruence and there is a directed path from $A$ to $B$ if and only i

Michael Mazilu, Joerg Baumgartl, Kishan Dholakia

For over a century diffraction theory has been thought to limit the resolution of focusing and imaging in the optical domain. The size of the smallest spot achievable is inversely proportional to the range of spatial wavevectors available. Here, we show that it is possible to locally beat the diffraction limit at the expense of efficiency. The method is base

Andrii R. Dmytryshyn, Vyacheslav Futorny, Vladimir V. Sergeichuk

V.I. Arnold [Russian Math. Surveys 26 (2) (1971) 29-43] constructed a miniversal deformation of matrices under similarity; that is, a simple normal form to which not only a given square matrix A but all matrices B close to it can be reduced by similarity transformations that smoothly depend on the entries of B. We construct a miniversal deformation of matric

L. Ma, G. F. Chen, Dao-Xin Yao, J. Zhang

We report the $^{23}$Na and $^{75}$As NMR studies on NaFeAs single crystals. The structure transition temperature $T_S$ (55 K) and the spin density wave (SDW) transition temperature $T_{SDW}$ (40.5 K) are determined by the NMR line splits. The spin-lattice relaxation rates indicate that the spin fluctuations are strongly enhanced just below $T_S$ and drive a

Loet Leydesdorff, Tobias Opthof

Impact factors (and similar measures such as the Scimago Journal Rankings) suffer from two problems: (i) citation behavior varies among fields of science and therefore leads to systematic differences, and (ii) there are no statistics to inform us whether differences are significant. The recently introduced SNIP indicator of Scopus tries to remedy the first o

José P. S. Lemos, Vilson T. Zanchin

In general relativity coupled to Maxwell's electromagnetism and charged matter, when the gravitational potential $W^2$ and the electric potential field $ϕ$ obey a relation of the form $W^{2}= a\left(-ε\, ϕ+ b\right)^2 +c$, where $a$, $b$ and $c$ are arbitrary constants, and $ε=\pm1$ (the speed of light $c$ and Newton's constant $G$ are put to one), a

S. James Gates, Konstantinos Koutrolikos

We discuss the higher superspin superfield formalism of Kuzenko et al from the basis of a unified treatment of an unconstrained spinorial superfield prepotential, its action and a restricted set of gauge transformations. We recover previous results as distinct limits of this unified treatment and give the first derivations of the complete set of Bianchi iden

Michael Mulligan, Chetan Nayak, Shamit Kachru

We study a novel abelian gauge theory in 2+1 dimensions which has surprising theoretical and phenomenological features. The theory has a vanishing coefficient for the square of the electric field $e_i^2$, characteristic of a quantum critical point with dynamical critical exponent $z=2$, and a level-$k$ Chern-Simons coupling, which is {\it marginal} at this c

Ryo Saotome, Ratindranath Akhoury, David Garfinkle

Numerical simulations are performed of a test scalar field in a spacetime undergoing gravitational collapse. The behavior of the scalar field near the singularity is examined and implications for generic singularities are discussed. In particular, our example is the first confirmation of the BKL conjecture for an asymptotically flat spacetime.

Andrei V. Frolov

In this paper I review the theory and numerical simulations of non-linear dynamics of preheating, a stage of dynamical instability at the end of inflation during which homogeneous inflaton explosively decays and deposits its energy into excitation of other matter fields. I focus on preheating in chaotic inflation models, which proceeds via broad parametric r

Asimina Arvanitaki, Sergei Dubovsky

It has recently been suggested that the presence of a plenitude of light axions, an Axiverse, is evidence for the extra dimensions of string theory. We discuss the observational consequences of these axions on astrophysical black holes through the Penrose superradiance process. When an axion Compton wavelength is comparable to the size of a black hole, the a

Diana Battefeld, Thorsten Battefeld

We investigate particle production near extra species loci (ESL) in a higher dimensional field space and derive a speed limit in moduli space at weak coupling. This terminal velocity is set by the characteristic ESL-separation and the coupling of the extra degrees of freedom to the moduli, but it is independent of the moduli's potential if the dimensiona

Patrick S. Fleming, Stephan Ramon Garcia, Gizem Karaali

We study the representation theory of a certain finite group for which Kloosterman sums appear as character values. This leads us to consider a concrete family of commuting hermitian matrices which have Kloosterman sums as eigenvalues. These matrices satisfy a number of "magical" combinatorial properties and they encode various arithmetic properties

Teppei Okumura, Y. P. Jing

The linear growth factor of density perturbations is believed to be a powerful observable of future redshift surveys to probe physical properties of dark energy and to distinguish among gravity theories. We investigate systematic effects on determination of the growth factor f from a measurement of redshift-space distortions. Using N-body simulations we iden

Lise Christensen, Sandro D'Odorico, Max Pettini, Vasily Belokurov

We confirm an eighth gravitational lens system in the CASSOWARY catalogue. Exploratory observations with the X-shooter spectrograph on the VLT show the system CSWA5 to consist of at least three images of a blue star-forming galaxy at z = 1.0686, lensed by an apparent foreground group of red galaxies one of which is at z = 0.3877. The lensed galaxy exhibits a

C. G. Lacey, C. M. Baugh, C. S. Frenk, A. J. Benson

We make a detailed investigation of the properties of Lyman-break galaxies (LBGs) in the LambdaCDM model. We present predictions for two published variants of the GALFORM semi-analytical model: the Baugh et al. (2005) model, which has star formation at high redshifts dominated by merger-driven starbursts with a top-heavy IMF, and the Bower et al. (2006) mode

Marc Kamionkowski

Cosmological birefringence, a rotation by an angle $α$ of the polarization of photons as they propagate over cosmological distances, is constrained by the cosmic microwave background (CMB) to be $|α|\lesssim1^\circ$ ($1σ$) out to redshifts $z\simeq1100$ for a rotation that is uniform across the sky. However, the rotation angle $α(θ,ϕ)$ may vary as a function

Chiaki Hikage, Masahiro Takada, Takashi Hamana, David Spergel

We develop a pseudo power spectrum technique for measuring the lensing power spectrum from weak lensing surveys in both the full sky and flat sky limits. The power spectrum approaches have a number of advantages over the traditional correlation function approach. We test the pseudo spectrum method by using numerical simulations with square-shape boundary tha

Bindusar Sahoo, Ho-Ung Yee

We construct new gravity backgrounds holographic dual to neutral plasma with U(1) global symmetry in the presence of constant electric field, considering its full back-reactions to the metric. As the electric field and the induced current cause a net energy in-flow to the system, the plasma is continually heated up and the corresponding gravity solution has

Christoph Pfrommer, Tom W. Jones

We present a consistent 3D model for the head-tail radio galaxy NGC 1265 that explains the complex radio morphology and spectrum by a past passage of the galaxy and radio bubble through a shock wave. Using analytical solutions to the full Riemann problem and hydrodynamical simulations, we study how this passage transformed the plasma bubble into a toroidal v

Yunhui Zhu, E. Cabrera-Granado, Oscar G. Calderon, Sonia Melle

We observe competition between the modulation instability (MI) and stimulated Brillouin scattering (SBS) in a 9.2-GHz broadband SBS slow light device, in which a standard 20-km-long single-mode LEAF fibre is used as the SBS medium. We find that MI is dominant and depletes most of the pump power when we use an intense pump beam at ~1.55 {\mu}m, where the LEAF

David M. Kipping, Gáspár Á. Bakos

We present two independent, homogeneous, global analyses of the transit light curves, radial velocities and spectroscopy of Kepler-4b through Kepler-8b, with numerous differences over the previous methods. These include: 1) improved decorrelated parameter fitting set, 2) new limb darkening coefficients, 3) time-stamps modified to BJD for consistency with RV,

Chethan Krishnan

Recently it was shown by Castro, Maloney and Strominger (CMS) that 4D Kerr black holes have a "hidden" conformal symmetry. Using some old results of Cvetic and Larsen, I show that this result is very likely to hold also for the most general black holes in five dimensions arising from heterotic/type II string theory. In particular, we show how the wav

Constantine Yannouleas, Uzi Landman

Orbital-free (OF) methods promise significant speed-up of computations based on density functional theory (DFT). In this field, the development of accurate kinetic-energy density functionals remains an open question. In this chapter we review the shell-correction method (SCM, commonly known as Strutinsky's averaging method) applied originally in nuclear

M. Strikman, C. Weiss

The transverse densities in a fast-moving nucleon offer a model-independent framework for analyzing the spatial structure of the pion cloud and its role in current matrix elements. We calculate the chiral large-distance component of the charge density using a dispersion representation of the form factor and discuss its partonic interpretation. The non-chiral

PHENIX Collaboration, A. Adare, S. Afanasiev, C. Aidala

The PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) has performed systematic measurements of phi meson production in the K+K- decay channel at midrapidity in p+p, d+Au, Cu+Cu and Au+Au collisions at sqrt(S_NN)=200 GeV. Results are presented on the phi invariant yield and the nuclear modification factor R_AA for Au+Au and Cu+Cu, and R_dA for d

Andrea Mehner, Kris Davidson, Roberta M. Humphreys, John C. Martin

Major stellar-wind emission features in the spectrum of Eta Car have recently decreased by factors of order 2 relative to the continuum. This is unprecedented in the modern observational record. The simplest, but unproven, explanation is a rapid decrease in the wind density.

Grzegorz Szamel

We clarify the relation between the ergodicity breaking transition predicted by mode-coupling theory and the so-called dynamic transition predicted by the static replica approach. Following Franz and Parisi [Phys. Rev. Lett. 79, 2486 (1997)], we consider a system of particles in a metastable state characterized by non-trivial correlations with a quenched con

S. Cawston, L. Vostrikova

We study exponential Levy models with change-point which is a random variable, independent from initial Levy processes. On canonical space with initially enlarged filtration we describe all equivalent martingale measures for change-point model and we give the conditions for the existence of f-divergence minimal equivalent martingale measure. Using the connec

Victor M. Preciado, Ali Jadbabaie

It is well-known that the behavior of many dynamical processes running on networks is intimately related to the eigenvalue spectrum of the network. In this paper, we address the problem of inferring global information regarding the eigenvalue spectrum of a network from a set of local samples of its structure. In particular, we find explicit relationships bet

M. Toorani, A. A. Beheshti

The signcryption is a relatively new cryptographic technique that is supposed to fulfill the functionalities of encryption and digital signature in a single logical step. Although several signcryption schemes are proposed over the years, some of them are proved to have security problems. In this paper, the security of Han et al.'s signcryption scheme is

ALICE Collaboration

The pseudorapidity density and multiplicity distribution of charged particles produced in proton-proton collisions at the LHC, at a centre-of-mass energy $\sqrt{s} = 7$ TeV, were measured in the central pseudorapidity region |$η$| < 1. Comparisons are made with previous measurements at $\sqrt{s}$ = 0.9 TeV and 2.36 TeV. At $\sqrt{s}$ = 7 TeV, for events with

Victor Rotger, Marco Adamo Seveso

Let f be a modular eigenform of even weight k>0 and new at a prime p dividing exactly the level, with respect to an indefinite quaternion algebra. The theory of Fontaine-Mazur allows to attach to f a monodromy module D_FM(f) and an L-invariant L_FM(f). The first goal of this paper is building a suitable p-adic integration theory that allows us to construct a

H. Farajollahi, F. Milani

In this paper we consider FRW cosmology in modified gravity which contain arbitrary functions $f(ϕ)$. It is shown that the bouncing solution appears in the model whereas the equation of state (EoS) parameter crosses the phantom divider. The reconstruction of the model is also investigated with the aim to reconstruct the arbitrary functions and variables of t

L. Faccioli, A. G. Kim, R. Miquel, G. Bernstein

We study the effect of filter zero-point uncertainties on future supernova dark energy missions. Fitting for calibration parameters using simultaneous analysis of all Type Ia supernova standard candles achieves a significant improvement over more traditional fit methods. This conclusion is robust under diverse experimental configurations (number of observed

H. Farajollahi, A. Salehi

We study in this paper chameleon cosmology applied to Friedmann-Robertson-Walker space, which gives rise to the equation of state (EoS) parameter larger than -1 in the past and less than -1 today, satisfying current observations. We also study cosmological constraints on the model using the time evolution of the cosmological redshift of distant sources which

Kenneth L. Pryor

This paper presents a new application of brightness temperature difference (BTD) between Geostationary Operational Environmental Satellite (GOES) imager channels 3 and 4. It has been found recently that the BTD between GOES infrared channel 3 (water vapor) and channel 4 (thermal infrared) can highlight regions where severe outflow wind generation (i.e. downb

M. N. Bannerman, R. Sargant, L. Lue

Molecular-dynamics algorithms for systems of particles interacting through discrete or &#34;hard&#34; potentials are fundamentally different to the methods for continuous or &#34;soft&#34; potential systems. Although many software packages have been developed for continuous potential systems, software for discrete potential systems based on event-driven algo

Anastasios Taliotis

Currently there exists no known way to construct the Stress-Energy Tensor $(T_{μν})$ of the produced medium in heavy ion collisions at strong coupling from purely theoretical grounds. In this paper, some steps are taken in that direction. In particular, the evolution of $T_{μν}$ at strong coupling and at high energies is being studied for early proper times

Bang-Hai Wang, Qin Li, Dongyang Long

In this paper, we show that an arbitrary separable state can be the output of a certain entanglement-breaking channel corresponding exactly to the input of a maximally entangled state. A necessary and sufficient separability criterion and some sufficient separability criteria from entanglement-breaking channels are given.

H. Weigel, M. Quandt

We improve on a method to compute the fermion contribution to the vacuum polarization energy of string-like configurations in a non-Abelian gauge theory. We establish the new method by numerically verifying the invariance under (a subset of) local gauge transformations. This also provides further support for the use of spectral methods to compute vacuum pola

Martin Kilbinger

Context. Weak gravitational lensing is a powerful probe of large-scale structure and cosmology. Most commonly, second-order correlations of observed galaxy ellipticities are expressed as a projection of the matter power spectrum, corresponding to the lowest-order approximation between the projected and 3d power spectrum. Aims. The dominant lensing-only contr

Pierre de Fouquieres, Sophie G. Schirmer

The control landscape for various canonical quantum control problems is considered. For the class of pure-state transfer problems, analysis of the fidelity as a functional over the unitary group reveals no suboptimal attractive critical points (traps). For the actual optimization problem over controls in $L^2(0,T)$, however, there are critical points for whi

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

The construction of a nonautonomous mixed mKdV/sine-Gordon model is proposed by employing an infinite dimensional affine Lie algebraic structure within the zero curvature representation. A systematic construction of soliton solutions is provided by an adaptation of the dressing method which takes into account arbitrary time dependent functions. A particular

Roman Vershynin

Given a probability distribution in R^n with general (non-white) covariance, a classical estimator of the covariance matrix is the sample covariance matrix obtained from a sample of N independent points. What is the optimal sample size N = N(n) that guarantees estimation with a fixed accuracy in the operator norm? Suppose the distribution is supported in a c

Andrea Banfi, Mrinal Dasgupta, Kamel Khelifa-Kerfa, Simone Marzani

We consider jet-shape observables of the type proposed recently, where the shapes of one or more high-pT jets, produced in a multi-jet event with definite jet multiplicity, may be measured leaving other jets in the event unmeasured. We point out the structure of the full next-to-leading logarithmic resummation specifically including resummation of non-global

Sergey V. Shevchenko, Vladimir V. Tokarevsky

This article presents and grounds (i.e. presents proof of the existence, the truth, the self-consistence and the completeness of) the informational concept ("the Information as Absolute" concept) in philosophy and sciences, which was developing from 2007 year till now. The concept defines the Information as ultimately common, real and fundamental "absolute"

Ioannis Papageorgiou

We are interested in Sobolev type inequalities and their relationship with concentration properties on higher dimensions. We consider unbounded spin systems on the d-dimensional lattice with interactions that increase slower than a quadratic. At first we assume that the one site measure satisfies a Modified log-Sobolev inequality with a constant uniformly on

Uffe Haagerup, Steen Thorbjørnsen

Let g:{\mathbb R} --> {\mathbb C} be a C^{\infty}-function with all derivatives bounded and let tr_n denote the normalized trace on the n x n matrices. In the paper [EM] Ercolani and McLaughlin established asymptotic expansions of the mean value E{tr_n(g(X_n))} for a rather general class of random matrices X_n,including the Gaussian Unitary Ensemble (GUE). U

Carlos M. Lorenzetti, Ana G. Maguitman

This paper proposes an incremental method that can be used by an intelligent system to learn better descriptions of a thematic context. The method starts with a small number of terms selected from a simple description of the topic under analysis and uses this description as the initial search context. Using these terms, a set of queries are built and submitt

Shinsuke Koyama, Lucia Castellanos Pérez-Bolde, Cosma Rohilla Shalizi, Robert E. Kass

State-space models provide an important body of techniques for analyzing time-series, but their use requires estimating unobserved states. The optimal estimate of the state is its conditional expectation given the observation histories, and computing this expectation is hard when there are nonlinearities. Existing filtering methods, including sequential Mont

M. H. Mohammady, G. W. Morley, T. S. Monteiro

We investigate theoretically and experimentally the electron paramagnetic resonance (EPR) spectra of bismuth doped silicon (Si:Bi) at intermediate magnetic fields, $B \approx 0.05 -0.6$ T. We identify a previously unexplored EPR regime of &#34;cancellation-resonances&#34;- where part of the hyperfine coupling is resonant with the external field-induced split

Vittorio Lubicz

I review lattice calculations and results for hadronic parameters relevant for kaon physics, in particular the vector form factor f+(0) of semileptonic kaon decays, the ratio fK/fpi of leptonic decay constants and the kaon bag parameter BK. For each lattice calculation a colour code rating is assigned, by following a procedure which is being proposed by the

Michael J. Gruber, Daniel H. Lenz, Ivan Veselić

We study spectral properties of Schrödinger operators on $\RR^d$. The electromagnetic potential is assumed to be determined locally by a colouring of the lattice points in $\ZZ^d$, with the property that frequencies of finite patterns are well defined. We prove that the integrated density of states (spectral distribution function) is approximated by its fini

Y. H. Ahn, Sin Kyu Kang, C. S. Kim, T. Phong Nguyen

We study how leptogenesis can be implemented in a seesaw model with $S_4$ flavor symmetry, which leads to the neutrino tri-bimaximal mixing matrix and degenerate right-handed (RH) neutrino spectrum. Introducing a tiny soft $S_4$ symmetry breaking term in the RH neutrino mass matrix, we show that the flavored resonant leptogenesis can be successfully realized

Jānis Priede

This paper considers the stability of liquid metal drops subject to a high-frequency AC magnetic field. An energy variation principle is derived in terms of the surface integral of the scalar magnetic potential. This principle is applied to a thin perfectly conducting liquid disk, which is used to model the drops constrained in a horizontal gap between two p

P. S. Howe, U. Lindstrom, L. Wulff

The $α&#39;^2$ deformation of D=10 SYM is the natural generalisation of the $F^4$ term in the abelian Born-Infeld theory. It is shown that this deformation can be extended to $α&#39;^4$ in a way which is consistent with supersymmetry. The latter requires the presence of higher-derivative and commutator terms as well as the symmetrised trace of the Born-Infel

V. Azcoiti, G. Di Carlo, E. Follana, A. Vaquero

The Vafa-Witten arguments on the realization of parity and flavour symmetries in the QCD vacuum do not apply to two lattice regularizations of QCD which are able to reproduce the chiral anomaly: Wilson fermions and Ginsparg-Wilson fermions. We show here how using the last regularization one can get, from first principles, that the more standard order paramet

Eveline Legendre

We study compatible toric Sasaki metrics with constant scalar curvature on co-oriented compact toric contact manifolds of Reeb type of dimension at least 5. These metrics come in rays of transversal homothety due to the possible rescaling of the Reeb vector fields. We prove that there exist Reeb vector fields for which the transversal Futaki invariant (restr