March 2009 arXiv papers — page 7

Henri Cohen, Fabien Pazuki

In this expository paper, we show how to use in practice 3-descent with a 3-isogeny to find an estimate for the rank of an elliptic curve having a rational 3-torsion subgroup, and we also give a geometric interpretation of these computations.

Ioannis Koukoutsidis

This review paper presents analytical information regarding the transfer of TCP data flows on paths towards interconnected wireless systems, with emphasis on 3G cellular networks. The focus is on protocol modifications in face of problems arising from terminal mobility and wireless transmission. The objective of this paper is not to present an exhaustive rev

Guy Barles, Sepideh Mirrahimi, Benoît Perthame

We study two equations of Lotka-Volterra type that describe the Darwinian evolution of a population density. In the first model a Laplace term represents the mutations. In the second one we model the mutations by an integral kernel. In both cases, we use a nonlinear birth-death term that corresponds to the competition between the traits leading to selection.

Sergey L. Gavrilyuk, Henri Gouin

The dynamics of the Reynolds stress tensor for turbulent flows is described with an evolution equation coupling both geometric effects and turbulent source terms. The effects of the mean flow geometry are shown up when the source terms are neglected: the Reynolds stress tensor is then expressed as the sum of three tensor products of vector fields which are g

Dibyendu Roy, Abhiram Soori, Diptiman Sen, Abhishek Dhar

We use Lippman-Schwinger scattering theory to study nonequilibrium electron transport through an interacting open quantum dot. The two-particle current is evaluated exactly while we use perturbation theory to calculate the current when the leads are Fermi liquids at different chemical potentials. We find an interesting two-particle resonance induced by the i

D. W. Darg, S. Kaviraj, C. J. Lintott, K. Schawinski

We present the largest, most homogeneous catalogue of merging galaxies in the nearby universe obtained through the Galaxy Zoo project - an interface on the world-wide web enabling large-scale morphological classification of galaxies through visual inspection of images from the Sloan Digital Sky Survey (SDSS). The method converts a set of visually-inspected c

Sasun Hambardzumyan, Vahan V. Mkrtchyan, Vahe L. Musoyan, Hovhannes Sargsyan

A {\it clutter} (or {\it antichain} or {\it Sperner family}) $L$ is a pair $(V,E)$, where $V$ is a finite set and $E$ is a family of subsets of $V$ none of which is a subset of another. Usually, the elements of $V$ are called {\it vertices} of $L$, and the elements of $E$ are called {\it edges} of $L$. A subset $s_e$ of an edge $e$ of a clutter is called {\i

Christopher M. Hirata

We investigate the effect of orientation-dependent selection effects on galaxy clustering in redshift space. It is found that if galaxies are aligned by large-scale tidal fields, then these selection effects give rise to a dependence of the observed galaxy density on the local tidal field, in addition to the well-known dependences on the matter density and r

Elena Kosygina, Thomas S. Mountford, Martin P. W. Zerner

We consider quenched and annealed Lyapunov exponents for the Green's function of $-Δ+γV$, where the potentials $V(x), x\in\Z^d$, are i.i.d. nonnegative random variables and $γ>0$ is a scalar. We present a probabilistic proof that both Lyapunov exponents scale like $c\sqrtγ$ as $γ$ tends to 0. Here the constant $c$ is the same for the quenched as for the

Ling-Nan Zou

Myelin figures are interfacial structures formed when certain surfactants swell in excess water. Here, I present data and model calculations suggesting myelin formation and growth is due to the fluid flow of surfactant, driven by the hydration gradient at the dry surfactant/water interface; a simple model based on this idea qualitatively reproduces the vario

S. Jeyakumar

Hydrodynamical simulations of jets interacting with clouds moving in the ambient medium of the host galaxy are presented. Clouds with sizes of the order of the jet diameter and smaller, crossing the path of the jet with different speeds are considered. In the case of slow moving clouds the jet is stopped over the brief period of time taken by the cloud to cr

Alexander Bolonkin, Mark Krinker

A method and facilities for delivering payload and people into outer space are presented. This method uses, in general, engines located on a planetary surface. The installation consists of a space apparatus, power drive stations, which include a flywheel accumulator (for storage) of energy, a variable reducer, a powerful homopolar electric generator and elec

Yousef Sobouti

Wherever one talks of dark matter, one does so where there is an observable matter and an associated unsolved dynamical issue to be settled. We promote this observation to the status of an axiom and conjecture that there is a dark companion to every baryonic matter, subject to certain rules as regards its size, distribution. To pursue the proposition in a sy

Nobuaki Yagita

Let p be an odd prime. Let G be a p-local finite group over the extraspecial p-group p_+^{1+2}. In this paper we study the cohomology and the stable splitting of their p-complete classifying space BG.

Elvan Ceyhan

Proximity catch digraphs (PCDs) are based on proximity maps which yield proximity regions and are special types of proximity graphs. PCDs are based on the relative allocation of points from two or more classes in a region of interest and have applications in various fields. In this article, we provide auxiliary tools for and various characterizations of PCDs

Derek Bodin, Chris DeCleene, William Hager, Carolyn Otto

In this paper, we study moduli spaces of 2-dimensional complex associative algebras. We give a complete calculation of the cohomology of every element in the moduli space, as well as compute their versal deformations.

Grant Walker, R M W Wood

The purpose of this paper is to forge a direct link between the hit problem for the action of the Steenrod algebra A on the polynomial algebra P(n)=F_2[x_1,...,x_n], over the field F_2 of two elements, and semistandard Young tableaux as they apply to the modular representation theory of the general linear group GL(n,F_2). The cohits Q^d(n)=P^d(n)/P^d(n)\cap

Peter Symonds

Goerss, Henn, Mahowald and Rezk construct a complex of permutation modules for the Morava stabilizer group G_2 at the prime 3. We describe how this can be done using techniques from homological algebra.

Nguyen Sum

We compute the action of the primitive Steenrod-Milnor operations on generators of algebras of invariants of subgroups of general linear group GL_n=GL(n,F_p) in the polynomial algebra with p an odd prime number.

Larry Smith

The purpose of these notes is to provide an introduction to the Steenrod algebra in an algebraic manner avoiding any use of cohomology operations. The Steenrod algebra is presented as a subalgebra of the algebra of endomorphisms of a functor. The functor in question assigns to a vector space over a Galois field the algebra of polynomial functions on that vec

Vo T N Quynh

In this paper, we show that Singer's fifth transfer is not an epimorphism in degree 11. More precisely, it does not detect the element P(h_2) in Ext_A^{5,16}(F_2,F_2).

J. E. Howard, J. D. Meiss

We investigate periodic straight-line orbits (SLO) in Hamiltonian force fields using both direct and inverse methods. A general theorem is proven for natural Hamiltonians quadratic in the momenta in arbitrary dimension and specialized to two and three dimension. Next we specialize to homogeneous potentials and their superpositions, including the familiar Hén

Derek Bodin, Christopher DeCleene, William Hager, Carolyn Otto

In this paper, we study the moduli space of $1|1$-dimensional complex associative algebras. We give a complete calculation of the cohomology of every element in the moduli space, as well as compute their versal deformations.

Fabio J. Valentim

Fix a smooth function $Φ: [l,r] \to \bb R$, defined on some interval $[l,r]$ of $\bb R$, such that $0<b \le Φ&#39;\le b^{-1}$. We prove that the evolution, on the diffusive scale, of the empirical density of exclusion processes in $\bb Z^d$, with conductances given by special class of functions $W$, is described by the weak solutions of the non-linear parabo

Geoffrey M L Powell

A new and natural description of the category of unstable modules over the Steenrod algebra as a category of comodules over a bialgebra is given; the theory extends and unifies the work of Carlsson, Kuhn, Lannes, Miller, Schwartz, Zarati and others. Related categories of comodules are studied, which shed light upon the structure of the category of unstable m

Aurore Savoy-Navarro, Alex Charpy, Catalin Ciobanu, Jacques David

Some preliminary thoughts on how to design and develop the DAQ architecture for the Silicon tracking system at the future Linear electron positron collider, are briefly presented here. The proposed structure includes three DAQ levels. The first level is based on a high level processing mix-mode ASIC sitting on the detector. The second level still on the dete

David J Pengelley, Frank Williams

We describe bialgebras of lower-indexed algebraic Steenrod operations over the field with p elements, p an odd prime. These go beyond the operations that can act nontrivially in topology, and their duals are closely related to algebras of polynomial invariants under subgroups of the general linear groups that contain the unipotent upper triangular groups. Th

A. V. Dudko, N. I. Nessonov

Let $\mathfrak{S}_\infty$ be the infinity permutation group and $Γ$ be a separable topological group. The wreath product $Γ\wr \mathfrak{S}_\infty$ is the semidirect product $Γ^\infty_e \rtimes \mathfrak{S}_\infty$ for the usual permutation action of $\mathfrak{S}_\infty$ on $Γ^\infty_e=\{[γ_i]_{i=1}^\infty : γ_i\in Γ,\textit{only finitely many}γ_i\neq e\}$.

Elodie Salmon, Françoise Behar, François Lorant, Patrick G. Hatcher

In this work, we develop a theoretical approach to evaluate maturation process of kerogen-like material, involving molecular dynamic reactive modeling with a reactive force field to simulate the thermal stress. The Morwell coal has been selected to study the thermal evolution of terrestrial organic matter. To achieve this, a structural model is first constru

Andrew T. McCallum, Mark Johnson

Spintronics is a new paradigm for integrated digital electronics. Recently established as a niche for nonvolatile magnetic random access memory (MRAM), it offers new functionality while demonstrating low power and high speed performance. However, to reach high density spintronic technology must make a transition to the nanometer scale. Prototype devices are

J H Palmieri

The action of Sq on the cohomology of the Steenrod algebra is induced by an endomorphism Theta of the Lambda algebra. This paper studies the behavior of Theta in order to understand the action of Sq; the main result is that Sq is injective in filtrations less than 4, and its kernel on the 4-line is computed.

Pham Anh Minh

Let P be the extraspecial p-group of order p^{2n+1}, of p-rank n+1, and of exponent p if p>2. Let Z be the center of P and let kappa_{n,r} be the characteristic classes of degree 2^n - 2^r (resp. 2(p^n-p^r)) for p=2 (resp. p>2), 0 <= r <= n-1, of a degree p^n faithful irreducible representation of P. It is known that, modulo nilradical, the iotath powers of

Tetsuo Hyodo, Wolfram Weise

We study the consequence of chiral SU(3) symmetry in the kaon-nucleon phenomenology, by deriving the effective single-channel KbarK N potential. It turns out that the pi Sigma interaction is strongly attractive and plays an important role for the structure of the Lambda(1405) resonance. We discuss the implication of effective potential for the few-body kaoni

Mamoru Mimura, Tetsu Nishimoto

We determine the Stiefel-Whitney classes of the second exterior representation and the spin representation of Spin(15), which are useful to calculate the mod 2 cohomology of the classifying space of the exceptional Lie group E_8.

Yanpeng Qi, Lei Wang, Zhaoshun Gao, Dongliang Wang

Using one-step solid state reaction method, we have successfully synthesized the superconductor SrFe1-xRuxAs. X-ray diffraction indicates that the material has formed the ThCr2Si2-type structure with a space group I4/mmm. The systematic evolution of the lattice constants demonstrates that the Fe ions are successfully replaced by the Ru. By increasing the dop

Paul Hoyer

Amplitudes of hard {\it exclusive} processes such as γ^*(Q^2) N \to γY, where Y=N (DVCS) or any other state with a limited mass (M_Y^2 << Q^2), factorize into a hard subprocess amplitude and a target (transition) GPD. The corresponding {\it inclusive} cross section, summed over all states Y of a given (limited) mass, is then given by the discontinuity of a f

Michael Schreiber

J. E. Hirsch (2005) introduced the h-index to quantify an individual&#39;s scientific research output by the largest number h of a scientist&#39;s papers, that received at least h citations. This so-called Hirsch index can be easily modified to take multiple co-authorship into account by counting the papers fractionally according to (the inverse of) the numb

Itaï Ben Yaacov

We present an adaptation of continuous first order logic to unbounded metric structures. This has the advantage of being closer in spirit to C. Ward Henson&#39;s logic for Banach space structures than the unit ball approach (which has been the common approach so far to Banach space structures in continuous logic), as well as of applying in situations where t

The Belle Collaboration, J. Wiechczynski, T. Lesiak

We report a measurement of the exclusive $B^+$ meson decay to the $D_s^{(*)-} K^+π^+$ final state using $657 \times 10^{6} B\overline{B}$ pairs collected at the $Υ(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider. We use $D_s^{*-}\to D_s^-γ$ and the $D_s^-\to ϕπ^-$, $\overline{K^{*}}(892)^0 K^-$ and $K^0_S K^-$ decay mod

Makoto Morinaga, Tetsuo Kishimoto

A new geometry to trap neutral particles with an ac electric field using a simple electrodes structure is described. In this geometry, all electrodes are placed on a single chip plane, while particles are levitated above the chip. This provides an easy construction of the trap and a good optical access to the trap.

Salim Bouzebda, Omar El-Dakkak

The purpose of this note is to provide an approximation for the generalized bootstrapped empirical process achieving the rate in Kolmos et al. (1975). The proof is based on much the same arguments as in Horvath et al. (2000). As a consequence, we establish an approximation of the bootstrapped kernel-type density estimator

Pushkar Ganesh Vaidya

In January 2004, the Stardust spacecraft flew through the dust of comet 81P/Wild 2 and captured specks of the cometary dust. On analysis of the comet 81P/Wild 2 samples, it was found that they contain materials found in the coldest and hottest region of the early solar nebula, strongly suggesting &#39;mixing&#39; on the grandest scale. Here it is suggested t

Karol Marty, Pierre Bordet, Virginie Simonet, Mickael Loire

The Fe-based langasites are the first reported compounds presenting a magnetic ordering in this rich family, besides being well known for piezo-electric properties and optical activity. The structural, magnetic and dielectric properties of the Fe langasite compounds, with various substitution of non-magnetic cations, have been studied with x-ray and neutron

Emir Pousse, Pierre-Alexandre Glaude, René Fournet, Frédérique Battin-Leclerc

To better understand the chemistry involved during the combustion of components of diesel fuel, the structure of a laminar lean premixed methane flame doped with n-butylbenzene has been investigated. The inlet gases contained 7.1% (molar) of methane, 36.8% of oxygen and 0.96% of n-butylbenzene corresponding to an equivalence ratio of 0.74 and a ratio C10H14

Hadj-Ali Gueniche, Pierre-Alexandre Glaude, René Fournet, Frédérique Battin-Leclerc

In order to better understand the importance of the different channels leading to the first aromatic ring, we have investigated, the structure of a laminar rich premixed methane flame doped with several unsaturated hydrocarbons: allene and propyne, as they are precursors of propargyl radicals, which are well known as having an important role in forming benze

Frédérique Battin-Leclerc, A. A. Konnov, J. L. Jaffrezo, M. Legrand

In order to better understand their potential formation in combustion systems, a detailed kinetic mechanism for the formation of short-chain monocarboxylic acids, formic (HCOOH), acetic (CH3COOH), propionic (C2H5COOH) and propenic (C2H3COOH)) acids, has been developed. Simulations of lean (equivalence ratios from 0.9 to 0.48) laminar premixed flames of propa

Pierre Bordet, Emmanuelle Suard

The crystal and magnetic structures of the three-leg ladder compound Fe3BO5 have been investigated by single crystal x-ray diffraction and neutron powder diffraction. Fe3BO5 contains two types of three-leg spin ladders. It shows a charge ordering transition at 283 K, an antiferromagnetic transition at 112 K, ferromagnetism below 70 K and a weak ferromagnetic

Ren-Yu Tian, Yu-Jun Zhao

P mono-doped and (P, N) co-doped ZnO are investigated by the first-principles calculations. It is found that substitutive P defect forms a deep acceptor level at O site (PO) and it behaves as a donor at Zn site (PZn), while interstitial P (Pi) is amphoteric. Under equilibrium conditions, these defects contribute little to the p-type conductivity of ZnO sampl

Malcolm Anderson

The linearly polarized gravitational waveforms from a certain type of rotating, evaporating cosmic string - the Allen-Casper-Ottewill loop - are constructed and plotted over the lifetime of the loop. The formulas for the waveforms are simple and exact, and describe waves which attenuate self-similarly, with the amplitude and period of the waves falling off l

Y. D. Jia, C. T. Russell, L. K. Jian, W. B. Manchester

This study examines the tail disconnection event on April 20, 2007 on comet 2P/Encke, caused by a coronal mass ejection (CME) at a heliocentric distance of 0.34 AU. During their interaction, both the CME and the comet are visible with high temporal and spatial resolution by the STEREO-A spacecraft. Previously, only current sheets or shocks have been accepted

Guo-Jie Gao, Jerzy Blawzdziewicz, Corey S. O&#39;Hern, Mark Shattuck

We developed a novel experimental technique to generate mechanically stable (MS) packings of frictionless granular disks. We performed a series of coordinated experiments and numerical simulations to enumerate the MS packings in small 2D systems composed of bidisperse disks. We find that frictionless MS packings occur as discrete, well-separated points in co

Lianlin Li, Fang Li

Compressive sensing claims that the sparse signals can be reconstructed exactly from many fewer measurements than traditionally believed necessary. One of issues ensuring the successful compressive sensing is to deal with the sparsity-constraint optimization. Up to now, many excellent theories, algorithms and software have been developed, for example, the so

Yi-Fu Cai, Wei Xue, Robert Brandenberger, Xinmin Zhang

We study the conditions under which thermal fluctuations generated in the contracting phase of a non-singular bouncing cosmology can lead to a scale-invariant spectrum of cosmological fluctuations at late times in the expanding phase. We consider point particle gases, holographic gases and string gases. In the models thus identified, we also study the therma

T. Sakurai, H. Tadano, Y. Kuramashi

It is well known that the block Krylov subspace solvers work efficiently for some cases of the solution of differential equations with multiple right-hand sides. In lattice QCD calculation of physical quantities on a given configuration demands us to solve the Dirac equation with multiple sources. We show that a new block Krylov subspace algorithm recently p

J. O. Stenflo

2008 marks the 100th anniversary of the discovery of astrophysical magnetic fields, when George Ellery Hale recorded the Zeeman splitting of spectral lines in sunspots. With the introduction of Babcock&#39;s photoelectric magnetograph it soon became clear that the Sun&#39;s magnetic field outside sunspots is extremely structured. The field strengths that wer

Oscar M. Perdomo

In this paper we will prove that for every integer n>1, there exists a real number H_0<-1 such that every H\in (-\infty,H_0) can be realized as the mean curvature of a embedding of H^{n-1}\times S^1 in the (n+1)-dimensional spaces H^{n+1}. For $n=2$ we explicitly compute the value H_0. For a general value n, we provide function ξ_n defined on (-\infty,-1), w

J. -R. Si, D. -M. Lu

Let $A$ be a bi-Koszul algebra, we describe all possible $A_\infty$-algebra structures on the Ext-algebra $E(A)$, and prove that $E(A)$ must be $[m_2, m_3]$-finitely generated. An equivalent description for a connected graded algebra to be a bi-Koszul algebra is given in terms of $A_\infty$-language. The case that $E(A)$ is endowed with minimal number of mul

Hui Zhao, Matt Mower, G. Vignale

We report theoretical and experimental studies of ambipolar spin diffusion in a semiconductor. A circularly polarized laser pulse is used to excite spin-polarized carriers in a GaAs multiple quantum well sample at 80 K. Diffusion of electron and spin densities is simultaneously measured using a spatially and temporally resolved pump-probe technique. Two regi

Petar Kormushev, Kohei Nomoto, Fangyan Dong, Kaoru Hirota

A technique for speeding up reinforcement learning algorithms by using time manipulation is proposed. It is applicable to failure-avoidance control problems running in a computer simulation. Turning the time of the simulation backwards on failure events is shown to speed up the learning by 260% and improve the state space exploration by 12% on the cart-pole

Leonardo Spanu, Davide Donadio, Detlef Hohl, Giulia Galli

We present computer simulations of liquid and solid phases of condensed methane at pressures below 25 GPa, between 150 and 300 K, where no appreciable molecular dissociation occurs. We used molecular dynamics (MD) and metadynamics techniques, and empirical potentials in the rigid molecule approximation, whose validity was confirmed a posteriori by carrying o

Guy F. de Teramond, Stanley J. Brodsky

We reply to L. Ya. Glozman&#39;s Comment &#34;Is a consistent holographic description of excited hadrons with fixed $L$ possible?&#34; In general, the solutions of the bound state Hamiltonian equation of motion in QCD have Fock state components with different $L$, and consequently hadronic relativistic wave equations derived in the framework of light-front h

Victor Gryaznov, Igor Iosilevskiy

An effective approach for construction of simple approximation for description of non-ideality effects in classical one- and two-component plasma model is under discussion. General constraints i.e. positiveness and exponential type for radial distribution functions F2(r) combined with normalizing (local electroneutrality) conditions, which validity is indepe

M. M. Selim

The present paper has been framed to show the effect of damping on the propagation of torsional waves in an initially stressed, dissipative, incompressible cylinder of infinite length. A governing equation has been formulated on Biot&#39;s incremental deformation theory. The velocities of torsional waves are obtained as complex ones, in which real part gives

Adrian Liu, Max Tegmark, Judd Bowman, Jacqueline Hewitt

21 cm tomography is expected to be difficult in part because of serious foreground contamination. Previous studies have found that line-of-sight approaches are capable of cleaning foregrounds to an acceptable level on large spatial scales, but not on small spatial scales. In this paper, we introduce a Fourier-space formalism for describing the line-of-sight

Christopher M. Hirata, John Forbes

Cosmological constraints from the cosmic microwave background (CMB) anisotropies rely on accurate theoretical calculations of the cosmic recombination history. Recent work has emphasized the importance of radiative transfer calculations due to the high optical depth in the HI Lyman lines. Transfer in the Lyman-alpha line is dominated by true emission and abs

Tobias Schmidt

Let $L$ be a proper finite extension of the field of $p$-adic numbers and let $o\subset L$ be its integers, viewed as an abelian locally $L$-analytic group. Let $\hat{o}$ be the rigid analytic group variety parametrizing the locally analytic characters of o. We study the Picard group and the Grothendieck group of this variety. This preprint is in final versi

T. A. Witten

We propose an explanation for the commonly-seen fading in the density of a stain remaining after a droplet has dried on a surface. The density decreases as a power $p$ of the distance from the edge. For thin, dilute drops of general shape this power is determined by a flow stagnation point in the distant interior of the drop. The power $p$ depends on the loc

D. Savransky, N. J. Kasdin, E. Cady

We present a framework for the analysis of direct detection planet finding missions using space telescopes. This framework generates simulations of complete missions, with varying populations of planets, to produce ensembles of mission simulations, which are used to calculate distributions of mission science yields. We describe the components of a mission si

James A. Maxin, Van E. Mayes, Dimitri V. Nanopoulos

We calculate the direct dark matter detection spin-independent and proton spin-dependent cross-sections for a semi-realistic intersecting D6-brane model. The cross-sections are compared to the latest constraints of the current dark matter direct detection experiments, as well as the projected results of future dark matter experiments. The allowed parameter s

Mathias Dietzel, Sandra M. Troian

Experiments by several groups during the past decade have shown that a molten polymer nanofilm subject to a large transverse thermal gradient undergoes spontaneous formation of periodic nanopillar arrays. The prevailing explanation is that coherent reflections of acoustic phonons within the film cause a periodic modulation of the radiation pressure which enh

Don N. Page

The Born rule may be stated mathematically as the rule that probabilities in quantum theory are expectation values of a complete orthogonal set of projection operators. This rule works for single laboratory settings in which the observer can distinguish all the different possible outcomes corresponding to the projection operators. However, theories of inflat

E. Z. Kurmaev, J. McLeod, N. A. Skorikov, L. D. Finkelstein

Results of resonant inelastic X-ray scattering (RIXS) measurements at Fe L-edges and electronic structure calculations of LiFeAs and NaFeAs are presented. Both experiment and theory show that in the vicinity of the Fermi energy, the density of states is dominated by contributions from Fe 3d-states. The comparison of Fe L2,3 non-resonant and resonant (excited

N. C. Plumb, T. J. Reber, J. D. Koralek, Z. Sun

Using low-photon energy angle-resolved photoemission (ARPES), we study the low-energy dispersion along the nodal (pi, pi) direction in Bi(2)Sr(2)CaCu(2)O(8+delta) (Bi2212) as a function of temperature. Less than 10 meV below the Fermi energy, the high-resolution data reveals a novel &#34;kink&#34;-like feature in the real part of the electron self-energy tha

Erwin T. Lau, Andrey V. Kravtsov, Daisuke Nagai

We present analysis of bulk and random gas motions in the intracluster medium using high-resolution Eulerian cosmological simulations of sixteen simulated clusters, including both very relaxed and unrelaxed systems and spanning a virial mass range of 5*10^13 - 2*10^15 Msun/h. We investigate effects of the residual subsonic gas motions on the hydrostatic esti

Louis Leblond, Benjamin Shlaer, Xavier Siemens

We analyze the gravitational wave signatures of a network of metastable cosmic strings. We consider the case of cosmic string instability to breakage, with no primordial population of monopoles. This scenario is well motivated from GUT and string theoretic models with an inflationary phase below the GUT/string scale. The network initially evolves according t

G. B. Shpiz, G. L. Litvinov

A tropical version of the Schauder fixed point theorem for compact subsets of tropical linear spaces is proved.

Mark C. Neyrinck, István Szapudi, Alexander S. Szalay

We find that nonlinearities in the dark-matter power spectrum are dramatically smaller if the density field first undergoes a logarithmic mapping. In the Millennium simulation, this procedure produces a power spectrum with a shape hardly departing from the linear power spectrum for k <~ 1 h/Mpc at all redshifts. Also, this procedure unveils pristine Fisher i

D. Deming, S. Seager, J. Winn, E. Miller-Ricci

Doppler and transit surveys are finding extrasolar planets of ever smaller mass and radius, and are now sampling the domain of superEarths (1-3 Earth radii). Recent results from the Doppler surveys suggest that discovery of a transiting superEarth in the habitable zone of a lower main sequence star may be possible. We evaluate the prospects for an all-sky tr

Scott A. Hughes

Largely motivated by the development of highly sensitive gravitational-wave detectors, our understanding of merging compact binaries and the gravitational waves they generate has improved dramatically in recent years. Breakthroughs in numerical relativity now allow us to model the coalescence of two black holes with no approximations or simplifications. Ther

Simon Catterall, David B. Kaplan, Mithat Unsal

We provide an introduction to recent lattice formulations of supersymmetric theories which are invariant under one or more real supersymmetries at nonzero lattice spacing. These include the especially interesting case of ${\cal N}=4$ SYM in four dimensions. We discuss approaches based both on twisted supersymmetry and orbifold-deconstruction techniques and s

A. Dubey, L. B. Reid, K. Weide, K. Antypas

FLASH is a publicly available high performance application code which has evolved into a modular, extensible software system from a collection of unconnected legacy codes. FLASH has been successful because its capabilities have been driven by the needs of scientific applications, without compromising maintainability, performance, and usability. In its newest

Wieslaw A. Dudek, Valentin s. Trokhimenko

We consider two relations on a $\cap$-semigroup of partial functions of a given set: the inclusion of domains and the semiadjacencity (i.e., the inclusion of the image of the first function into the domain of the second), which characterized with an abstract point of view using the elementary system of axioms, i.e., system conditions, recorded in the languag

José Figueroa-O&#39;Farrill

We phrase deformations of n-Leibniz algebras in terms of the cohomology theory of the associated Leibniz algebra. We do the same for n-Lie algebras and for the metric versions of n-Leibniz and n-Lie algebras. We place particular emphasis on the case of n=3 and explore the deformations of 3-algebras of relevance to three-dimensional superconformal Chern--Simo

N. Sator, H. Hietala

Using a simple and generic molecular dynamics model, we study the damage in a disc of interacting particles as the disc fragments upon impact with a wall. The damage, defined as the ratio of the number of bonds broken by the impact to the initial number of bonds, is found to increase logarithmically with the energy deposited in the system. This result implie

P. R. Eastham, N. R. Cooper, D. K. K. Lee

We present and solve a model for the vortex configuration of a disordered quantum Hall bilayer in the limit of strong and smooth disorder. We argue that there is a characteristic disorder strength below which vortices will be rare, and above which they proliferate. We predict that this can be observed tuning the electron density in a given sample. The ground

Stefan Palzer, Christoph Zipkes, Carlo Sias, Michael Köhl

We investigate the propagation of spin impurity atoms through a strongly interacting one-dimensional Bose gas. The initially well localized impurities are accelerated by a constant force, very much analogous to electrons subject to a bias voltage, and propagate as a one-dimensional impurity spin wave packet. We follow the motion of the impurities in situ and

S. Guillot, R. E. Rutledge, E. F. Brown, G. G. Pavlov

This paper presents the analysis of candidate quiescent low mass xray binarie (qLMXBs) observed during a short Chandra/ACIS observation of the globular cluster (GC) NGC 6304. Two out of the three candidate qLMXBs of this cluster, XMMU 171433-292747 and XMMU 171421-292917, lie within the field of view. This permits comparison with the discovery observation of

Benjamin P. Moster, Rachel S. Somerville, Christian Maulbetsch, Frank C. van den Bosch

We use a statistical approach to determine the relationship between the stellar masses of galaxies and the masses of the dark matter halos in which they reside. We obtain a parameterized stellar-to-halo mass (SHM) relation by populating halos and subhalos in an N-body simulation with galaxies and requiring that the observed stellar mass function be reproduce

Ayan Khan, Rajneesh Atre, Prasanta K. Panigrahi

Experimentally observed grey solitons are analytically extracted from a physically viable \GP equation. Associated Lieb and Bogoliubov modes are calculated for these class of solitons. It is observed that, these nonlinear excitations have strong coupling with the trap at low momenta and hence can be effectively isolated from the Bogoliubov sound modes, which

G. M. Bruun

We develop an effective low energy theory for multi-channel scattering of cold atomic alkali atoms with particular focus on Feshbach resonances. The scattering matrix is expressed in terms of observables only and the theory allows for the inclusion of many-body effects both in the open and in the closed channels. We then consider the frequency and damping of

Bernd Gärtner, Martin Jaggi, Clément Maria

For a variety of regularized optimization problems in machine learning, algorithms computing the entire solution path have been developed recently. Most of these methods are quadratic programs that are parameterized by a single parameter, as for example the Support Vector Machine (SVM). Solution path algorithms do not only compute the solution for one partic

Christophe Gallesco

We consider, in the continuous time version, $γ$ independent random walks on $\mathbb{Z_+}$ in random environment in the Sinai&#39;s regime. Let $T_\gam$ be the first meeting time of one pair of the $γ$ random walks starting at different positions. We first show that the tail of the quenched distribution of $T_γ$, after a suitable rescaling, converges in pro

Arjen van der Wel, Eric F. Bell, Frank C. van den Bosch, Anna Gallazzi

We present a simple, empirically motivated model that simultaneously predicts the evolution of the mean size and the comoving mass density of massive early-type galaxies from z=2 to the present. First we demonstrate that some size evolution of the population can be expected simply due to the continuous emergence of early-type galaxies. SDSS data reveal that

CLEO Collaboration, N. Lowrey

The first measurements of the coherence factors (R_Kpipi0 and R_K3pi) and the average strong-phase differences (delta_D^Kpipi0 and delta_D^K3pi) for D0->K-pi+pi0 and D0->K-pi+pi+pi- are presented. These parameters can be used to improve the determination of the unitarity triangle angle gamma in B^- -> DK^- decays, where D is a D^0 or Dbar^0 meson decaying to

Fuminori Sakaguchi, Masahito Hayashi

In this paper, for an operator defined by the action of an M-th order differential operator with rational-type coefficients on the function space L_k^2(R):={f: measurable | \|f\|_k <\infty} with norm \|f\|_k^2:= \int |f(x)|^2 (x^2+1)^k dx (k \in Z), we prove the regularity (continuity and differentiability up to M times) of the eigenfunctions of its closure

Lars Bergstrom

An overview is given of various dark matter candidates. Among the many suggestions given in the literature, axions, inert Higgs doublet, sterile neutrinos, supersymmetric particles and Kaluza-Klein particles are discussed. The situation has recently become very interesting with new results on antimatter in the cosmic rays having dark matter as one of the lea

Christopher Ferrie, Joseph Emerson

Building on earlier work, we further develop a formalism based on the mathematical theory of frames that defines a set of possible phase-space or quasi-probability representations of finite-dimensional quantum systems. We prove that an alternate approach to defining a set of quasi-probability representations, based on a more natural generalization of a class

Aniket Magarkar, Anirban Banerji, Shweta Kolhi

Biological systems possess negative entropy. In them, one form of order produces another, more organized form of order. We propose a formal scheme to calculate robustness of an entire biological system by quantifying the negative entropy present in it. Our Methodology is based upon a computational implementation of two-person non-cooperative finite zero-sum

Sheikh Shajidul Haque, Akikazu Hashimoto

We investigate the relationship between mass and spin of quark anti-quark bound state in non-commutative gauge theory with N=4 supersymmetry. In the large N and large 't Hooft coupling limit, these bound states correspond to rotating open strings ending on a D-brane embedded into the supergravity background dual of the non-commutative field theory. Although

Qingguo Feng, Yuzhong Zhang, Harald O. Jeschke

In this paper a fast impurity solver is proposed for dynamical mean field theory (DMFT) based on a decoupling of the equations of motion for the impurity Greens function. The resulting integral equations are solved efficiently with a method based on genetic algorithms. The Hubbard and periodic Anderson models are studied with this impurity solver. The method