July 2009 arXiv papers — page 22

A. V. Jayanthan

In this article, we show that the depths of the associated graded ring and fiber cone of a lex-segment ideal in $K[x,y]$ are equal.

Felix Filatov

The structure of the genetic code is discussed in formal terms. A rectangular table of the code ("the code matrix"), whose properties reveal its arithmetical content tagged with the information symbols in several notations. New parameters used to analyze of the code matrix, the serial numbers of the encoded products and coding elements, ordered by mo

Shengqiang Zhou, K. Potzger, Qingyu Xu, G. Talut

Recently theoretical works predict that some semiconductors (e.g. ZnO) doped with magnetic ions are diluted magnetic semiconductors (DMS). In DMS magnetic ions substitute cation sites of the host semiconductor and are coupled by free carriers resulting in ferromagnetism. One of the main obstacles in creating DMS materials is the formation of secondary phases

Alberto Accardi, Francois Arleo, William K. Brooks, David D'Enterria

We review recent progress in the study of parton propagation, interaction and fragmentation in both cold and hot strongly interacting matter. Experimental highlights on high-energy hadron production in deep inelastic lepton-nucleus scattering, proton-nucleus and heavy-ion collisions, as well as Drell-Yan processes in hadron-nucleus collisions are presented.

Michael Bohn

Using adiabatic limits of Eta invariants, Rho invariants of the total space of a fiber bundle are investigated. One concern is to formulate the aspects of local index theory for families of Dirac operator in terms of the odd signature operator, and place known results in a context which permits the treatment of Rho invariants. The main focus is, however, to

Gerson Goldhaber

It is now about 10 years since the evidence, based on Type Ia supernovae, for the acceleration of the expansion of the Universe was discovered. I will discuss some aspects of the work and events in the Supernova Cosmology Project (SCP), during the period 1988 to 1998, which led to this discovery.

Carri W. Chan, Nick Bambos

We consider the problem of dynamically scheduling J jobs on N processors for non-preemptive execution where the value of each job (or the reward garnered upon completion) decays over time. All jobs are initially available in a buffer and the distribution of their service times are known. When a processor becomes available, one must determine which free job t

Tony Gherghetta, Daniel Sword

The formalism for modeling multiple fermion generations in a warped extra dimension with a soft-wall is presented. A bulk Higgs condensate is responsible for generating mass for the zero-mode fermions but leads to additional complexity from large mixing between different flavors. We extend existing single-generation analyses by considering new special cases

S. G. Djorgovski, P. Hut, S. McMillan, E. Vesperini

We describe the Meta-Institute for Computational Astrophysics (MICA), the first professional scientific organization based exclusively in virtual worlds (VWs). The goals of MICA are to explore the utility of the emerging VR and VWs technologies for scientific and scholarly work in general, and to facilitate and accelerate their adoption by the scientific res

S. K. Adhikari, L. Salasnich

By direct numerical simulation of the time-dependent Gross-Pitaevskii equation we study different aspects of the localization of a non-interacting ideal Bose-Einstein condensate (BEC) in a one-dimensional bichromatic quasi-periodic optical-lattice potential. Such a quasi-periodic potential, used in a recent experiment on the localization of a BEC [Roati et a

Xin Liu, Nadia L. Zakamska, Jenny E. Greene, Michael A. Strauss

We present deep Gemini GMOS optical spectroscopy of nine luminous quasars at redshifts z ~ 0.5, drawn from the SDSS type 2 quasar sample. Our targets were selected to have high intrinsic luminosities (M_V < -26 mag) as indicated by the [O III] 5007 A emission-line luminosity (L_[O III]). Our sample has a median black hole mass of ~ 10^8.8 M_sun inferred assu

Irene Bredberg, Thomas Hartman, Wei Song, Andrew Strominger

The superradiant scattering of a scalar field with frequency and angular momentum (ω,m) by a near-extreme Kerr black hole with mass and spin (M,J) was derived in the seventies by Starobinsky, Churilov, Press and Teukolsky. In this paper we show that for frequencies scaled to the superradiant bound the full functional dependence on (ω,m,M,J) of the scattering

A. M. Velasquez-Toribio

We study the matter density fluctuations in the running cosmological constant (RCC) model using linear perturbations in the longitudinal gauge. Using this observable we calculate the growth rate of structures and the matter power spectrum, and compare them with the $SDSS$ data and other available data of the linear growth rate. The distribution of collapsed

Werner Mueller, Alexander Strohmaier

Scattering theory for p-forms on manifolds with cylindrical ends has a direct interpretation in terms of cohomology. Using the Hodge isomorphism,the scattering matrix at low energy may be regarded as operator on the cohomology of the boundary. Its value at zero describes the image of the absolute cohomology in the cohomology of the boundary. We show that the

S. Cox, R. D. McDonald, J. Singleton, S. Miller

We report unexpected behaviour in a family of Cu spin- 1/2 systems, in which an apparent gap in the low energy magneto-optical absorption spectrum opens at low temperature. This previously unreported collective phenomenon arises at temperatures where the energy of the dominant exchange interaction exceeds the thermal energy. Simulations of the observed shift

P. L. Paulose, C. S. Yadav, K. M. Subhedar

We report a comparative study of the series Fe1.1Te1-xSex and the stoichiometric FeTe1-xSex to bring out the difference in their magnetic, superconducting and electronic properties. The Fe1.1Te1-xSex series is found to be magnetic and its microscopic properties are elucidated through Moessbauer spectroscopy. The magnetic phase diagram of Fe1.1Te1-xSex is tra

Casim Abbas

Emmanuel Giroux showed that every contact structure on a closed three dimensional manifold is supported by an open book decomposition. We will extend this result by showing that the open book decomposition can be chosen in such a way that the pages are solutions to a homologically perturbed Holomorphic Curve equation.

Olivier Wantz

This is the first in a series of papers which ultimately aims on improving on the present estimates on the axion mass by modeling the topological non-perturbative QCD dynamics. Axions couple to instantons and their mass is set by the topological susceptibility whose temperature dependence we estimate with the interacting instanton liquid model (IILM). Since

Steven S. Gubser, Christopher P. Herzog, Silviu S. Pufu, Tiberiu Tesileanu

We establish that in a large class of strongly coupled 3+1 dimensional N=1 quiver conformal field theories with gravity duals, adding a chemical potential for the R-charge leads to the existence of superfluid states in which a chiral primary operator of the schematic form O = λλ+ W condenses. Here λis a gluino and W is the superpotential. Our argument is bas

Andrew Scott Waugh, Liuyi Pei, James H. Fowler, Peter J. Mucha

We measure polarization in the United States Congress using the network science concept of modularity. Modularity provides a conceptually-clear measure of polarization that reveals both the number of relevant groups and the strength of inter-group divisions without making restrictive assumptions about the structure of the party system or the shape of legisla

Daniel S. Freed, John Lott

Let X --> B be a proper submersion with a Riemannian structure. Given a differential K-theory class on X, we define its analytic and topological indices as differential K-theory classes on B. We prove that the two indices are the same.

Francisco M. Fernández

We obtain the radius of convergence of the small--amplitude approximation to the period of the nonlinear oscillator $\ddot{x}+(1+\dot{x}^{2})x=0$ with the initial conditions $x(0)=A$ and $\dot{x}(0)=0$ and show that the inverted perturbation series appears to converge smoothly from below.

Victor Chernozhukov, Sokbae Lee, Adam M. Rosen

We develop a practical and novel method for inference on intersection bounds, namely bounds defined by either the infimum or supremum of a parametric or nonparametric function, or equivalently, the value of a linear programming problem with a potentially infinite constraint set. We show that many bounds characterizations in econometrics, for instance bounds

Bin Han

In this paper, we study nonhomogeneous wavelet systems which have close relations to the fast wavelet transform and homogeneous wavelet systems. We introduce and characterize a pair of frequency-based nonhomogeneous dual wavelet frames in the distribution space; the proposed notion enables us to completely separate the perfect reconstruction property of a wa

O. Lopez, A. Amy-Klein, M. Lours, Ch. Chardonnet

We report the first demonstration of a long-distance ultra stable frequency dissemination in the microwave range. A 9.15 GHz signal is transferred through a 86-km urban optical link with a fractional frequency stability of 1.3x10-15 at 1 s integration time and below 10-18 at one day. The optical link phase noise compensation is performed with a round-trip me

Maxim Perelstein, Andrew Spray

The hierarchy problem can be addressed by extending the four-dimensional space-time to include an extra compact spatial dimension with non-trivial &#34;warped&#34; metric, as first suggested by Randall and Sundrum. If the Randall-Sundrum framework is realized in string theory, the effective value of the string scale in the vicinity of the infrared boundary s

K. Belczynski, D. R. Lorimer, J. P. Ridley, S. J. Curran

We investigate the statistics of isolated recycled pulsars and double neutron star binaries in the Galactic disk. Since recycled pulsars are believed to form through accretion and spinup in close binaries, the isolated objects presumably originate from disrupted progenitors of double neutron stars. There are a comparable number of double neutron star systems

Elena D&#39;Onghia, Volker Springel, Lars Hernquist, Dusan Keres

We employ numerical simulations and simple analytical estimates to argue that dark matter substructures orbiting in the inner regions of the Galaxy can be efficiently destroyed by disk shocking, a dynamical process known to affect globular star clusters. We carry out a set of fiducial high-resolution collisionless simulations in which we adiabatically grow a

Vladimir Y. Chernyak, Michael Chertkov, Sergey V. Malinin, Razvan Teodorescu

In many experimental situations, a physical system undergoes stochastic evolution which may be described via random maps between two compact spaces. In the current work, we study the applicability of large deviations theory to time-averaged quantities which describe such stochastic maps, in particular time-averaged currents and density functionals. We derive

Andrew R. Zentner

A potential flux of high-energy neutrinos from the annihilation of dark matter particles trapped within the Sun has been exploited to place indirect limits on particle dark matter. In most models, the dark matter interacts weakly, but the possibility of a dark matter particle with a large cross section for elastic scattering with itself has been proposed in

Jon Tyson

In a unified framework, we obtain two-sided estimates of the following quantities of interest in quantum information theory: 1.The minimum-error distinguishability of arbitrary ensembles of mixed quantum states. 2.The approximate reversibility of quantum dynamics in terms of entanglement fidelity. (This is also referred to as &#34;channel-adapted quantum err

Adam Rej

In this article we review the recently discovered asymptotic integrability in the planar N = 4 SYM theory and discuss its breakdown beyond the asymptotic region due to the wrapping interactions. We also discuss novel dynamical tests of the AdS/CFT correspondence one can perform in the special cases when the wrapping interactions may be neglected.

Ermes Braidot

Forward $π^0$ production has been measured at STAR with the new Forward Meson Spectrometer (FMS) from p+p and d+Au collisions during the 2008 RHIC run. We present the first FMS results of azimuthal correlation involving a forward $π^0$ produced in p+p and d+Au collisions to search for the onset of gluon density saturation, expected to occur at small momentum

V. Batista, Subo Dong, A. Gould, J. P. Beaulieu

We analyze OGLE-2007-BLG-050, a high magnification microlensing event (A ~ 432) whose peak occurred on 2 May, 2007, with pronounced finite-source and parallax effects. We compute planet detection efficiencies for this event in order to determine its sensitivity to the presence of planets around the lens star. Both finite-source and parallax effects permit a

G. A. Shields, D. J. Rosario, K. L. Smith, E. W. Bonning

The quasar SDSS J105041.35+345631.3 (z = 0.272) has broad emission lines blueshifted by 3500 km/s relative to the narrow lines and the host galaxy. Such an object may be a candidate for a recoiling supermassive black hole, binary black hole, a superposition of two objects, or an unusual geometry for the broad emission-line region. The absence of narrow lines

J. P. U. Fynbo, P. Jakobsson, J. X. Prochaska, D. Malesani

(Abridged). We present a sample of 77 optical afterglows (OAs) of Swift detected GRBs for which spectroscopic follow-up observations have been secured. We provide linelists and equivalent widths for all detected lines redward of Ly-alpha. We discuss to what extent the current sample of Swift bursts with OA spectroscopy is a biased subsample of all Swift dete

Adam Henry Marblestone, Michel Devoret

We consider classical and entanglement-assisted versions of a distributed computation scheme that computes nonlinear Boolean functions of a set of input bits supplied by separated parties. Communication between the parties is restricted to take place through a specific apparatus which enforces the constraints that all nonlinear, nonlocal classical logic is p

Christopher J Leininger

The main result of this paper, Simon's conjecture for fibered knots, was previously proven by Silver and Whitten math.GT/0405462 with essentially the same proof. This paper is therefore being withdrawn. The author would like to apologize for having missed this.

Fedor V. Fomin, Serge Gaspers, Saket Saurabh, Stéphan Thomassé

We present a polynomial time algorithm that for any graph G and integer k >= 0, either finds a spanning tree with at least k internal vertices, or outputs a new graph G&#39; on at most 3k vertices and an integer k&#39; such that G has a spanning tree with at least k internal vertices if and only if G&#39; has a spanning tree with at least k&#39; internal ver

Pierre Albin, Richard Melrose

The `Folk Theorem&#39; that a smooth action by a compact Lie group can be (canonically) resolved, by iterated blow up, to have unique isotropy type is proved in the context of manifolds with corners. This procedure is shown to capture the simultaneous resolution of all isotropy types in a `resolution tower&#39; which projects to a resolution, with iterated b

Ryan Orson Behunin, Bei-Lok Hu

Recently the Casmir-Polder force felt by an atom near a substrate under nonequilibrium stationary conditions has been studied theoretically with macroscopic quantum electrodyanamics (MQED) and verified experimentally with cold atoms. We give a quantum field theory derivation of the Langevin equation describing the atom&#39;s motion based on the influence fun

C. Fernandez-Ramirez, A. M. Bernstein, T. W. Donnelly

Contributions of $D$ waves to physical observables for neutral pion photoproduction from the proton in the near-threshold region are studied and means to isolate them are proposed. Various approaches to describe the multipoles are employed --a phenomenological one, a unitary one, and heavy baryon chiral perturbation theory. The results of these approaches ar

Adam D. Helfer

The energy-momentum and angular momentum contained in a spacelike two-surface of spherical topology are estimated by joining the two-surface to null infinity via an approximate no-incoming-radiation condition. The result is a set of gauge-invariant formulas for energy-momentum and angular momentum which should be applicable to much numerical work; it also gi

Helen Caines

The mechanisms underlying hadronization are not well understood, both in vacuum and in hot QCD matter. Precise characterization of jet fragmentation to hadrons in p-p collisions will help elucidate the fundamental process of hadronization, and will serve as essential reference to measure the modification of hadronization in heavy ion collisions. We present m

Frederick M. Goodman, John Graber

We study analogues of Jucys-Murphy elements in cellular algebras arising from repeated Jones basic constructions. Examples include Brauer and BMW algebras and their cyclotomic analogues.

Alessandro Rinaldo, Larry Wasserman

We study generalized density-based clustering in which sharply defined clusters such as clusters on lower-dimensional manifolds are allowed. We show that accurate clustering is possible even in high dimensions. We propose two data-based methods for choosing the bandwidth and we study the stability properties of density clusters. We show that a simple graph-b

Antoine Seguin, Yann Bertho, Philippe Gondret, Jerome Crassous

The penetration by a gravity driven impact of a solid sphere into a granular medium is studied by two-dimensional simulations. The scaling laws observed experimentally for both the final penetration depth and the stopping time with the relevant physical parameters are here recovered numerically without the consideration of any solid friction. Collisional pro

J. Lundberg, J. Conrad, W. Rolke, A. Lopez

A C++ class was written for the calculation of frequentist confidence intervals using the profile likelihood method. Seven combinations of Binomial, Gaussian, Poissonian and Binomial uncertainties are implemented. The package provides routines for the calculation of upper and lower limits, sensitivity and related properties. It also supports hypothesis tests

Reza M. Baram, Pedro G. Lind, José S. Andrade, Hans J. Herrmann

We study drag-induced diffusion of massive particles in scale-free velocity fields, where superdiffusive behavior emerges due to the scale-free size distribution of the vortices of the underlying velocity field. The results show qualitative resemblance to what is observed in fluid systems, namely the diffusive exponent for the mean square separation of pairs

M. Avila, A. P. Willis, B. Hof

The onset of shear flow turbulence is characterized by turbulent patches bounded by regions of laminar flow. At low Reynolds numbers localized turbulence relaminarises, raising the question of whether it is transient in nature or it becomes sustained at a critical threshold. We present extensive numerical simulations and a detailed statistical analysis of th

Frank Calegari

We prove some cases of the Fontaine-Mazur conjecture for even Galois representations. In particular, we prove, under mild hypotheses, that there are no irreducible two-dimensional ordinary even Galois representations of $\Gal(\Qbar/\Q)$ with distinct Hodge-Tate weights. If $K/\Q$ is an imaginary quadratic field, we also prove (again, under certain hypotheses

M. B. Altaie

I discuss some of the main interpretations given to explain the indeterministic nature of quantum measurements and show that all has some loopholes in one corner or another. I propose an alternative interpretation based on the notion of continued re-creation of the physical properties. The rate at which the system is re-created is a measure of the determinis

Piotr Dzierzak, Przemyslaw Malkiewicz, Wlodzimierz Piechocki

The big bounce (BB) transition within a flat Friedmann-Robertson-Walker model is analyzed in the setting of loop geometry underlying the loop cosmology. We solve the constraint of the theory at the classical level to identify physical phase space and find the Lie algebra of the Dirac observables. We express energy density of matter and geometrical functions

Hans-Karl Janssen, Frank Wevelsiep, Olaf Stenull

We present a dynamical field theory for directed randomly branched polymers and in particular their collapse transition. We develop a phenomenological model in the form of a stochastic response functional that allows us to address several interesting problems such as the scaling behavior of the swollen phase and the collapse transition. For the swollen phase

R. Khasanov, M. Bendele, A. Amato, P. Babkevich

We report an investigation into the superconducting and magnetic properties of Fe_{1+y}Se_{x}Te_{1-x} single crystals by magnetic susceptibility, muon spin rotation, and neutron diffraction. We find three regimes of behavior in the phase diagram for 0\leq x\leq 0.5: (i) commensurate magnetic order for x< 0.1, (ii) bulk superconductivity for $x\lesssim 0.1$,

Subhaditya Bhattacharya, Utpal Chattopadhyay, Debajyoti Choudhury, Debottam Das

We perform a multilepton channel analysis in the context of the Large Hadron Collider (LHC) for Wilkinson Microwave Anisotropy Probe (WMAP) compatible points in a model with non-universal scalar masses, which admits a Higgs funnel region of supersymmetry dark matter even for a small $\tanβ$. In addition to two and three-lepton final states, four-lepton event

Theodore Alexandrov, Klaus Steinhorst, Oliver Keszoecze, Stefan Schiffler

Mass spectrometry (MS) is an important technique for chemical profiling which calculates for a sample a high dimensional histogram-like spectrum. A crucial step of MS data processing is the peak picking which selects peaks containing information about molecules with high concentrations which are of interest in an MS investigation. We present a new procedure

Antoine Klein, Philippe Jetzer, Mauro Sereno

With one exception, previous analyses of the measurement accuracy of gravitational wave experiments for comparable-mass binary systems have neglected either spin-precession effects or subdominant harmonics and amplitude modulations. Here we give the first explicit description of how these effects combine to improve parameter estimation. We consider supermass

Anastasia Doikou, Nikos Karaiskos

We examine super symmetric representations of the B-type Hecke algebra. We exploit such representations to obtain new non-diagonal solutions of the reflection equation associated to the super algebra U_q(gl(m|n)). The boundary super algebra is briefly discussed and it is shown to be central to the super symmetric realization of the B-type Hecke algebra

Ravit Helled, Gerald Schubert, John D. Anderson

Anderson & Schubert (2007, Science,317,1384) proposed that Saturn's rotation period can be ascertained by minimizing the dynamic heights of the 100 mbar isosurface with respect to the geoid; they derived a rotation period of 10h 32m 35s. We investigate the same approach for Jupiter to see if the Jovian rotation period is predicted by minimizing the dynamical

Marcin Jurdziński, Ashutosh Trivedi

In a reachability-time game, players Min and Max choose moves so that the time to reach a final state in a timed automaton is minimised or maximised, respectively. Asarin and Maler showed decidability of reachability-time games on strongly non-Zeno timed automata using a value iteration algorithm. This paper complements their work by providing a strategy imp

M. A. Betemps, V. P. Goncalves, J. T. de Santana Amaral

The perturbative QCD predicts that the growth of the gluon density at small-$x$ (high energies) should saturate, forming a Color Glass Condensate (CGC), which is described in mean field approximation by the Balitsky-Kovchegov (BK) equation. Recently, the next-to-leading order corrections for the BK equation were derived and a global fit of the inclusive $ep$

Shaofang Hong, Jianrong Zhao, Wei Zhao

In this paper, we investigate the 2-adic valuations of the Stirling numbers $S(n, k)$ of the second kind. We show that $v_2(S(4i, 5))=v_2(S(4i+3, 5))$ if and only if $i\not\equiv 7\pmod {32}$. This confirms a conjecture of Amdeberhan, Manna and Moll raised in 2008. We show also that $v_2(S(2^n+1, k+1))= s_2(n)-1$ for any positive integer $n$, where $s_2(n)$

J. A. Aguilar-Saavedra

We systematically study the possible signals at LHC of new vector-like quarks mainly coupled to the third generation. We consider heavy quarks T, B, X, Y of charges 2/3, -1/3, 5/3 and -4/3, respectively, in SU(2)_L isosinglets T_{L,R}, B_{L,R}, or isodoublets (T B)_{L,R}, (X T)_{L,R} or (B Y)_{L,R}. Analyses based on a fast detector simulation are presented

Wei-Min Wang

We present a geometric formulation of existence of time quasi-periodic solutions. As an application, we prove the existence of quasi-periodic solutions of $b$ frequencies, $b\leq d+2$, in arbitrary dimension $d$ and for arbitrary non integrable algebraic nonlinearity $p$. This reflects the conservation of $d$ momenta, energy and $L^2$ norm. In 1d, we prove t

Jonathan Bouchet

The HFT, a new inner tracking detector for STAR, aims to measure the charmed hadron nuclear modification factor as well as their elliptic flow to the low $p_\mathrm{T}$ region ($\sim$0.5 GeV/c) by measuring the displaced vertices of charmed particles.

P. Fachini

The results on rho(770)0 production in Cu+Cu collisions at 200 and 62.4 GeV in STAR are presented. The rho0 is measured via its hadronic decay channel and used as a sensitive tool to examine the collision dynamics in the hadronic medium.

Stefano Pirandola

We consider a basic model of digital memory where each cell is composed of a reflecting medium with two possible reflectivities. By fixing the mean number of photons irradiated over each memory cell, we show that a non-classical source of light can retrieve more information than any classical source. This improvement is shown in the regime of few photons and

Somphong Jitman, Patanee Udomkavanich

The results of J. F. Qiann et al. [4] on $(1-γ)$-cyclic codes over finite chain rings of nilpotency index 2 are extended to $(1-γ^e)$-cyclic codes over finite chain rings of arbitrary nilpotency index $e+1$. The Gray map is introduced for this type of rings. We prove that the Gray image of a linear $(1 - γ^{e})$-cyclic code over a finite chain ring is a dist

Andrea Mazzino, Paolo Muratore-Ginanneschi, Stefano Musacchio

We inquire the statistical properties of the pair formed by the Navier-Stokes equation for an incompressible velocity field and the advection-diffusion equation for a scalar field transported in the same flow in two dimensions (2d). The system is in a regime of fully developed turbulence stirred by forcing fields with Gaussian statistics, white-noise in time

Gor Sarkissian

We perform canonical quantization of the WZW model with defects and permutation branes. We establish symplectomorphism between phase space of WZW model with $N$ defects on cylinder and phase space of Chern-Simons theory on annulus times $R$ with $N$ Wilson lines, and between phase space of WZW model with $N$ defects on strip and Chern-Simons theory on disc t

N. Chauvin, C. Zinoni, M. Francardi, A. Gerardino

We demonstrate that the presence of charge around a semiconductor quantum dot (QD) strongly affects its optical properties and produces non-resonant coupling to the modes of a microcavity. We first show that, besides (multi)exciton lines, a QD generates a spectrally broad emission which efficiently couples to cavity modes. Its temporal dynamics shows that it

Xiang Ni, Chengming Bai

We introduce a notion of pre-alternative algebra which may be seen as an alternative algebra whose product can be decomposed into two pieces which are compatible in a certain way. It is also the "alternative" analogue of a dendriform dialgebra or a pre-Lie algebra. The left and right multiplication operators of a pre-alternative algebra give a bimodule struc

Hsi-Yu Schive, Yu-Chih Tsai, Tzihong Chiueh

We present the newly developed code, GAMER (GPU-accelerated Adaptive MEsh Refinement code), which has adopted a novel approach to improve the performance of adaptive mesh refinement (AMR) astrophysical simulations by a large factor with the use of the graphic processing unit (GPU). The AMR implementation is based on a hierarchy of grid patches with an oct-tr

Teiji Kunihiro, Yuki Minami, Kyosuke Tsumura

The dynamical density fluctuations around QCD critical point (CP) are analyzed using relativistic dissipative fluid dynamics, and we show that the sound mode around the QCD CP is strongly attenuated whereas the thermal fluctuation stands out there. We speculate that if possible suppression or disappearance of a Mach cone, which seems to be created by the par

Itzhak Tamo, Moshe Schwartz

We study error-correcting codes for permutations under the infinity norm, motivated by a novel storage scheme for flash memories call rank modulation. In this scheme, a set of $n$ flash cells are combined to create a single virtual multi-level cell. Information is stored in the permutation induced by the cell charge levels. Spike errors, which are characteri

Sergei D. Mechveliani

We investigate the manifold $\cal{M}$ of (real) quadratic forms in n > 1 variables having a multiple eigenvalue. In addition to known facts, we prove that 1) $\cal{M}$ is irreducible, 2) in the case of n = 3, scalar matrices and only them are singular points on $\cal{M}$. For $n = 3$, $\cal{M}$ is also described as the straight cylinder over $\cal{M}$$_0$, w

Sourav Chatterjee

We prove that the Sherrington-Kirkpatrick model of spin glasses is chaotic under small perturbations of the couplings at any temperature in the absence of an external field. The result is proved for two kinds of perturbations: (a) distorting the couplings via Ornstein-Uhlenbeck flows, and (b) replacing a small fraction of the couplings by independent copies.

M. J. Kweon

The Transition Radiation Detector (TRD) for the ALICE experiment at the Large Hadron Collider (LHC) identifies electrons in p+p and in the challenging high multiplicity environment of heavy-ion collisions and provides fast online tracking for the ALICE Level1 trigger. The TRD is designed to have excellent position resolution and pion rejection capability. Pr

Chris Clarkson, Kishore Ananda, Julien Larena

We investigate the effect that the average backreaction of structure formation has on the dynamics of the cosmological expansion, within the concordance model. Our approach in the Poisson gauge is fully consistent up to second-order in a perturbative expansion about a flat Friedmann background, including a cosmological constant. We discuss the key length sca

Joachim Kopp, Viviana Niro, Thomas Schwetz, Jure Zupan

We consider the hypothesis that Dark Matter (DM) has tree-level interactions only with leptons. Such a framework, where DM recoils against electrons bound in atoms, has been proposed as an explanation for the annually modulated scintillation signal in DAMA/LIBRA versus the absence of a signal for nuclear recoils in experiments like CDMS or XENON10. However,

Hélène Esnault, Vikram Mehta

We show that simply connected projective manifolds in characteristic $p>0$ have no nontrivial stratified bundles. This gives a positive answer to a conjecture by D. Gieseker. The proof uses Hrushovski&#39;s theorem on periodic points.

Wojciech Broniowski, Alexandr E. Dorokhov, Enrique Ruiz Arriola

Twist-2 components of the real and virtual photon distribution amplitudes are evaluated in several chiral quark models. The results, obtained at the quark model scale, are then evolved to higher scales, probed in experiments or in lattice QCD. We also analyze the related form factors and coupling constants. Our results are a genuine dynamical prediction, fol

N. Marwan, J. F. Donges, Y. Zou, R. V. Donner

We propose a novel approach for analysing time series using complex network theory. We identify the recurrence matrix calculated from time series with the adjacency matrix of a complex network, and apply measures for the characterisation of complex networks to this recurrence matrix. By using the logistic map, we illustrate the potentials of these complex ne

Wael Bahsoun, Pawel Gora

We study Markov processes generated by iterated function systems (IFS). The constituent maps of the IFS are monotonic transformations of the interval. We first obtain an upper bound on the number of SRB (Sinai-Ruelle-Bowen) measures for the IFS. Then, when all the constituent maps have common fixed points at 0 and 1, theorems are given to analyze properties

D. D. Scherer, C. A. Müller, M. Kastner

The fidelity metric has recently been proposed as a useful and elegant approach to identify and characterize both quantum and classical phase transitions. We study this metric on the manifold of thermal states for the Lipkin-Meshkov-Glick (LMG) model. For the isotropic LMG model, we find that the metric reduces to a Fisher-Rao metric, reflecting an underlyin

Inigo Urizar-Lanz, Geza Toth

We consider a number operator-annihilation operator uncertainty as a well behaved alternative to the number-phase uncertainty relation, and examine its properties. We find a formulation in which the bound on the product of uncertainties depends on the expectation value of the particle number. Thus, while the bound is not a constant, it is a quantity that can

Giulia Ferrini, Anna Minguzzi, Frank W. J. Hekking

For a Bose Josephson junction realized with a double-well potential we propose a strategy to observe the coherent superpositions of phase states occurring during the time evolution after a sudden rise of the barrier separating the two wells. We show that their phase content can be obtained by the full-counting statistics of the spin-boson operators character

A. K. Chaudhuri

In a hydrodynamic model, we have studied $J/ψ$ suppression and elliptic flow in Au+Au collisions at RHIC energy $\sqrt{s}$=200 GeV. At the initial time, $J/ψ$&#39;s are randomly distributed in the fluid. As the fluid evolve in time, the free streaming $J/ψ$&#39;s are dissolved if the local fluid temperature exceeds a melting temperature $T_{J/ψ}$. Sequential

Takashi Kato

We study an optimal execution problem in a continuous-time market model that considers market impact. We formulate the problem as a stochastic control problem and investigate properties of the corresponding value function. We find that right-continuity at the time origin is associated with the strength of market impact for large sales, otherwise the value fu

Robert J. Adler, Gennady Samorodnitsky, Jonathan E. Taylor

We consider smooth, infinitely divisible random fields $(X(t),t\in M)$, $M\subset {\mathbb{R}}^d$, with regularly varying Levy measure, and are interested in the geometric characteristics of the excursion sets \[A_u=\{t\in M:X(t)>u\}\] over high levels u. For a large class of such random fields, we compute the $u\to\infty$ asymptotic joint distribution of th

Luke Kelly

We use a randomised embedding method to prove that for all α>0 any sufficiently large oriented graph G with minimum in-degree and out-degree δ^+(G),δ^-(G)\geq (3/8+α)|G| contains every possible orientation of a Hamilton cycle. This confirms a conjecture of Häggkvist and Thomason.

P. Hibon, J. -G. Cuby, J. Willis, B. Clément

The Ly-alpha luminosity function (LF) of high-redshift Ly-alpha emitters (LAEs) is one of the few observables of the re-ionization epoch accessible to date with 8-10 m class telescopes. The evolution with redshift allows one to constrain the evolution of LAEs and their role in re-ionizing the Universe at the end of the Dark Ages. We have performed a narrow-b

Alexander Gnedin, Grigori Olshanski

For positive $q\neq1$, the $q$-exchangeability of an infinite random word is introduced as quasi-invariance under permutations of letters, with a special cocycle which accounts for inversions in the word. This framework allows us to extend the $q$-analog of de Finetti&#39;s theorem for binary sequences---see Gnedin and Olshanski [Electron. J. Combin. 16 (200

D. Bonamy

Stress enhancement in the vicinity of brittle cracks makes the macro-scale failure properties extremely sensitive to the micro-scale material disorder. Therefore: (i) Fracturing systems often display a jerky dynamics, so-called crackling noise, with seemingly random sudden energy release spanning over a broad range of scales, reminiscent of earthquakes; (ii)

Vladimir Shevelev

For a prime p and nonnegative integers n,k, consider the set A_{n,k}^{(p)}={x is in [0,1,...,n]: p^k||binom {n} {x}}. Let the expansion of n+1 in base p be: n+1=alpha_{0} p^ν+alpha_{1}p^{nu-1}+...+alpha_{nu}, where 0<=alpha_{i}<= p-1,i=0,...,nu. Then the number n is called a binomial predictor in base p,if |A_{n,k}^{(p)}|=alpha_{k}p^{nu-k},k=0,1,...,nu. We g

Jenna Ryon, Matthew D. Shetrone, Graeme H. Smith

Measurements of the asymmetry of the emission peaks in the core of the Ca II H line for 105 giant stars are reported. The asymmetry is quantified with the parameter V/R, defined as the ratio between the maximum number of counts in the blueward peak and the redward peak of the emission profile. The Ca II H and K emission lines probe the differential motion of

Tanmay Deshpande

Let G be an algebraic group over an algebraically closed field of positive characteristic such that its neutral connected component is a unipotent group. We consider a certain class of closed idempotents in the braided monoidal category (under convolution of complexes) D_G(G) known as Heisenberg idempotents. For such an idempotent e, we will prove certain re

Mustapha Ouladsine, Gérard Bloch, Xavier Dovifaaz

The paper describes a neural approach for modelling and control of a turbocharged Diesel engine. A neural model, whose structure is mainly based on some physical equations describing the engine behaviour, is built for the rotation speed and the exhaust gas opacity. The model is composed of three interconnected neural submodels, each of them constituting a no

Mohsen Bayati, David F. Gleich, Amin Saberi, Ying Wang

Network alignment generalizes and unifies several approaches for forming a matching or alignment between the vertices of two graphs. We study a mathematical programming framework for network alignment problem and a sparse variation of it where only a small number of matches between the vertices of the two graphs are possible. We propose a new message passing