May 2008 arXiv papers — page 37

Yuji Kodama, Barbara Shipman

In 1967, Japanese physicist Morikazu Toda published the seminal papers exhibiting soliton solutions to a chain of particles with nonlinear interactions between nearest neighbors. In the decades that followed, Toda's system of particles has been generalized in different directions, each with its own analytic, geometric, and topological characteristics tha

E. W. Collings, M. D. Sumption, M. Bhatia, M. A. Susner

The magnetic and transport properties of magnesium diboride films represent performance goals yet to be attained by powder-processed bulk samples and conductors. Such performance limits are still out of the reach of even the best magnesium diboride magnet wire. In discussing the present status and prospects for improving the performance of powder-based wire

Harmen J. Warringa

Quantum Chromodynamics (QCD) predicts that topological charge changing transitions will take place in hot quark matter. Such transitions induce P- and CP-violating effects. We will show that in the presence of a magnetic field these transitions can separate quarks according to their electric charge along the direction of the magnetic field. This is the so-ca

Joshua Greene

Given a diagram of a link K in S^3, we write down a Heegaard diagram for the branched-double cover Sigma(K). The generators of the associated Heegaard Floer chain complex correspond to Kauffman states of the link diagram. Using this model we make some computations of the homology \hat{HF}(Sigma(K)) as a graded group. We also conjecture the existence of a del

R. Wunsch, G. Tenorio-Tagle, J. Palous, S. Silich

Using the hydrodynamic code ZEUS, we perform 2D simulations to determine the fate of the gas ejected by massive stars within super star clusters. It turns out that the outcome depends mainly on the mass and radius of the cluster. In the case of less massive clusters, a hot high velocity ($\sim 1000$ km s$^{-1}$) stationary wind develops and the metals inject

Fabio Bresolin

Many of the properties of massive stars in external galaxies, such as chemical compositions, mass functions, and ionizing fluxes, can be derived from the study of the associated clouds of ionized gas. Moreover, the signatures of Wolf-Rayet stars are often detected in the spectra of extragalactic H II regions. This paper reviews some aspects of the recent wor

F. Rincon, G. I. Ogilvie, M. R. E. Proctor, C. Cossu

Identifying generic physical mechanisms responsible for the generation of magnetic fields and turbulence in differentially rotating flows is fundamental to understand the dynamics of astrophysical objects such as accretion disks and stars. In this paper, we discuss the concept of subcritical dynamo action and its hydrodynamic analogue exemplified by the proc

Andres Pedroza

Let $(M,ω)$ be a closed symplectic manifold and $\textup{Ham}(M,ω)$ the group of Hamiltonian diffeomorphisms of $(M,ω)$. Then the Seidel homomorphism is a map from the fundamental group of $\textup{Ham}(M,ω)$ to the quantum homology ring $QH_*(M;Λ)$. Using this homomorphism we give a sufficient condition for when a nontrivial loop $ψ$ in $\textup{Ham}(M,ω)$

Nathalie Villa, Fabrice Rossi, Quoc-Dinh Truong

This paper briefly presents several ways to understand the organization of a large social network (several hundreds of persons). We compare approaches coming from data mining for clustering the vertices of a graph (spectral clustering, self-organizing algorithms. . .) and provide methods for representing the graph from these analysis. All these methods are i

Brendan Lucier

This paper classifies binary morphisms that map to ultimately periodic words. In particular, if a morphism h maps an infinite non-ultimately periodic word to an ultimately periodic word then it must be true that h(0) commutes with h(1).

Robert Williams, Elena Mason, Massimo Della Valle, Alessandro Ederoclite

A high-resolution spectroscopic survey of postoutburst novae reveals short-lived heavy element absorption systems in a majority of novae near maximum light, having expansion velocities of 400-1000 km/s and velocity dispersions between 35-350 km/s. A majority of systems are accelerated outwardly, and they all progressively weaken and disappear over timescales

S. Katsuda, K. Mori, H. Tsunemi, S. Park

We report on the discovery of fast-moving X-ray--emitting ejecta knots in the Galactic Oxygen-rich supernova remnant Puppis A from XMM-Newton observations. We find an X-ray knotty feature positionally coincident with an O-rich fast-moving optical filament with blue-shifted line emission located in the northeast of Puppis A. We extract spectra from northern a

J. M. Taylor, P. Cappellaro, L. Childress, L. Jiang

We present a novel approach to the detection of weak magnetic fields that takes advantage of recently developed techniques for the coherent control of solid-state electron spin quantum bits. Specifically, we investigate a magnetic sensor based on Nitrogen-Vacancy centers in room-temperature diamond. We discuss two important applications of this technique: a

P. Hennebelle, R. Banerjee, E. Vazquez-Semadeni, R. Klessen

{It has recently been proposed that giant molecular complexes form at the sites where streams of diffuse warm atomic gas collide at transonic velocities.} {We study the global statistics of molecular clouds formed by large scale colliding flows of warm neutral atomic interstellar gas under ideal MHD conditions. The flows deliver material as well as kinetic e

Matthew G. Coleman, Jelte T. A. de Jong

Based on a deep imaging survey, we present the first homogeneous star formation history (SFH) of the Fornax dwarf spheroidal (dSph) galaxy. We have obtained two-filter photometry to a depth of B ~ 23 over the entire surface of Fornax, the brightest dSph associated with the Milky Way, and derived its SFH using a CMD-fitting technique. We show that Fornax has

S. Simón-Díaz, G. Stasińska

We present a detailed comparison of the ionizing spectral energy distributions (SEDs) predicted by four modern stellar atmosphere codes, TLUSTY, CMFGEN, WMbasic, and FASTWIND. We consider three sets of stellar parameters representing a late O-type dwarf (O9.5 V), a mid O-type (O7 V) dwarf, and an early O-type dwarf (O5.5 V). We explore two different possibil

Aaron Levin

We give a new general technique for constructing and counting number fields with an ideal class group of nontrivial m-rank. Our results can be viewed as providing a way of specializing the Picard group of a variety V over $\mathbb{Q}$ to obtain class groups for number fields $\mathbb{Q}(P)$, $P\in V(\Qbar)$, for certain families of points P. In particular, w

Michael Joyce

The usual thermodynamic limit for systems of classical self-gravitating point particles becomes well defined, as a {\it dynamical} problem, using a simple physical prescription for the calculation of the force, equivalent to the so-called ``Jeans' swindle''. The relation of the resulting intrinsically out of equilibrium problem, of particles evolving from pr

François Guéritaud, Saul Schleimer

Every cusped, finite-volume hyperbolic three-manifold has a canonical decomposition into ideal polyhedra. We study the canonical decomposition of the hyperbolic manifold obtained by filling some (but not all) of the cusps with solid tori: in a broad range of cases, generic in an appropriate sense, this decomposition can be predicted from that of the unfilled

M. Mocak, E. Mueller, A. Weiss, K. Kifonidis

We investigate the hydrodynamics of the core helium flash near its peak. Past research concerned with the dynamics of this event is inconclusive. However, the most recent multidimensional hydrodynamic studies suggest a quiescent behavior and seem to rule out an explosive scenario. Previous work indicated, that depending on initial conditions, employed turbul

Wilhelm Kley, Richard Nelson

Over 30 planetary systems have been discovered to reside in binary stars. For small separations gravitational perturbation of the secondary star has a strong influence on the planet formation process. It truncates the protoplanetary disk, may shortens its lifetime, and stirs up the embedded planetesimals. Due to its small semi-major axis (18.5 AU) and large

Roy A. Lacey

A state-of-the-art 3D source imaging technique is used to extract the 3D two-pion source function in central and mid-central Au+Au collisions at $\sqrt{s_{NN}} = 200$ GeV. The source function indicates a previously unresolved non-Gaussian tail in the directions of the pion pair transverse momentum (out) and along the beam (long). Model comparisons give robus

Sergei A. Voloshin

Anisotropic flow measurements play a crucial role in understanding the physics and bulk properties of the system created in heavy ion collisions. In this talk I briefly review the most important results obtained so far, recent developments in the analysis techniques and the interpretation of the results, and what should we expect next, both at RHIC and LHC.

Marek Karpinski, Yakov Nekrich

We study a new variant of colored orthogonal range searching problem: given a query rectangle $Q$ all colors $c$, such that at least a fraction $τ$ of all points in $Q$ are of color $c$, must be reported. We describe several data structures for that problem that use pseudo-linear space and answer queries in poly-logarithmic time.

J. Heinrichs

We reconsider the problem of the enhancement of tunnelling of a quantum particle induced by disorder of a one-dimensional tunnel barrier of length $L$, using two different approximate analytic solutions of the invariant imbedding equations of wave propagation for weak disorder. The two solutions are complementary for the detailed understanding of important a

Aaron Levin

We consider some variations on the classical method of Runge for effectively determining integral points on certain curves. We first prove a version of Runge's theorem valid for higher-dimensional varieties, generalizing a uniform version of Runge's theorem due to Bombieri. We then take up the study of how Runge's method may be expanded by taking

Richard Durran, Andrew Neate, Aubrey Truman, Feng-Yu Wang

The correspondence limit of the atomic elliptic state in three dimensions is discussed in terms of Nelson's stochastic mechanics. In previous work we have shown that this approach leads to a limiting Nelson diffusion and here we discuss in detail the invariant measure for this process and show that it is concentrated on the Kepler ellipse in the plane z=

A. I. Ooms, M. Van den Bergh

For Lie algebras whose Poisson semi-center is a polynomial ring we give a bound for the sum of the degrees of the generating semi-invariants. This bound was previously known in many special cases.

S. Gustavsson, I. Shorubalko, R. Leturcq, T. Ihn

We use a nanowire quantum dot to probe high-frequency current fluctuations in a nearby quantum point contact. The fluctuations drive charge transitions in the quantum dot, which are measured in real-time with single-electron detection techniques. The quantum point contact (GaAs) and the quantum dot (InAs) are fabricated in different material systems, which i

Onur Ozan Koyluoglu, Hesham El Gamal, Lifeng Lai, H. Vincent Poor

This paper studies the K-user Gaussian interference channel with secrecy constraints. Two distinct network models, namely the interference channel with confidential messages and the one with an external eavesdropper, are analyzed. Using interference alignment along with secrecy pre-coding at each transmitter, it is shown that each user in the network can ach

Hiroshi Kamikado, Tetsuo Shindou, Eiichi Takasugi

We study the neutrino mass matrix derived from the seesaw mechanism in which the neutrino Yukawa couplings and the heavy Majorana neutrino mass matrix are controlled by the Froggatt-Nielsen mechanism. In order to obtain the large neutrino mixings, two Froggatt-Nielsen fields are introduced with a complex vacuum expectation values. As a by-product, CP violati

S. S. Agaev, M. A. Gomshi Nobary

Power-suppressed corrections arising from end-point integration regions to the space-like vertex function of the massive eta'-meson virtual gluon transition eta' - g*g* are computed. Calculations are performed within the standard hard-scattering approach (HSA) and the running coupling method supplemented by the infrared renormalon calculus. Contribut

Werner Bernreuther

The physics perspectives of the production and decay of single top quarks and top quark pairs at the CERN Large Hadron Collider (LHC) are reviewed from a phenomenological point of view.

R. Alvarez-Rodriguez, A. S. Jensen, E. Garrido, D. V. Fedorov

The complex scaled hyperspherical adiabatic expansion method is used to compute momentum and energy distributions of the three $α$-particles emerging from the decay of low-lying $^{12}$C-resonances. The large distance continuum properties of the wave functions are crucial and must be accurately calculated. We discuss separately decays of natural parity state

Huanyang Chen, C. T. Chan

We show that the optical properties of an oblique layered system with two kinds of isotropic materials can be described using the concept of transformation media as long as the thickness of the layers is much smaller than the wavelength. Once the connection with transformation media is established, we then show that oblique layered system can serve as a univ

Alfonso Martinez, Albert Guillen i Fabregas, Giuseppe Caire, Frans Willems

We revisit the information-theoretic analysis of bit-interleaved coded modulation (BICM) by modeling the BICM decoder as a mismatched decoder. The mismatched decoding model is well-defined for finite, yet arbitrary, block lengths, and naturally captures the channel memory among the bits belonging to the same symbol. We give two independent proofs of the achi

Anders Claesson, Sergey Kitaev

It is well-known, and was first established by Knuth in 1969, that the number of 321-avoiding permutations is equal to that of 132-avoiding permutations. In the literature one can find many subsequent bijective proofs of this fact. It turns out that some of the published bijections can easily be obtained from others. In this paper we describe all bijections

S. Krompiewski

This contribution reports on comparative studies on giant magnetoresistance (GMR) in carbon nanotubes (CNTs) and graphene nanoribbons of similar aspect ratios (i.e perimeter/length and width/length ratios, for the former and the latter, respectively). The problem is solved at zero temperature in the ballistic transport regime, by means of the Green's fun

S. D. Makovetskiy, D. N. Makovetskii

We report some qualitatively new features of emergence, competition and dynamical stabilization of dissipative rotating spiral waves (RSWs) in the cellular-automaton model of laser-like excitable media proposed in arXiv:cond-mat/0410460v2 ; arXiv:cond-mat/0602345 . Part of the observed features are caused by unusual mechanism of excitation vorticity when the

The BABAR Collaboration, B. Aubert

We present measurements of the CP-violation parameters S and C for the radiative decay B0 -> eta K0s gamma; for B -> eta K gamma we also measure the branching fractions and for B+ -> eta K+ gamma the time-integrated charge asymmetry Ach. The data, collected with the BaBar detector at the Stanford Linear Accelerator Center, represent $465 \times 10^6$ BBbar p

Pedro Cruz, Evgeny Lakshtanov

The scalar scattering of a plane wave by a smooth obstacle with impedance boundary conditions is considered. Upper bounds for the Total Cross Section and for the absorbed power are presented.

S. Bellucci, S. Ferrara, A. Marrani

We review recent results in the study of attractor horizon geometries (with non-vanishing Bekenstein-Hawking entropy) of dyonic extremal d=4 black holes in supergravity. We focus on N=2, d=4 ungauged supergravity coupled to a number n_{V} of Abelian vector multiplets, outlining the fundamentals of the special Kaehler geometry of the vector multiplets' sc

Samuel Johnson, J. Marro, Joaquin J. Torres

We study the effect of varying wiring in excitable random networks in which connection weights change with activity to mold local resistance or facilitation due to fatigue. Dynamic attractors, corresponding to patterns of activity, are then easily destabilized according to three main modes, including one in which the activity shows chaotic hopping among the

Andrea Loi, Fabio Zuddas

An $n$-dimensional Hartogs domain $D_F$ with strongly pseudoconvex boundary can be equipped with a natural Kaehler metric $g_F$. This paper contains two results. In the first one we prove that if $g_F$ is an extremal Kaehler metric then $(D_F, g_F)$ is holomorphically isometric to an open subset of the $n$-dimensional complex hyperbolic space. In the second

Brahim El Asri, Said Hamadene

In this paper we show existence and uniqueness of a solution for a system of m variational partial differential inequalities with inter-connected obstacles. This system is the deterministic version of the Verification Theorem of the Markovian optimal m-states switching problem. The switching cost functions are arbitrary. This problem is in relation with the

Luis Felipe Tabera

We introduce the notion of resultant of two planar curves in the tropical geometry framework. We prove that the tropicalization of the algebraic resultant can be used to compute the stable intersection of two tropical plane curves. It is shown that, for two generic preimages of the curves to an algebraic framework, their intersection projects exactly onto th

Alberto Elduque

Models of the exceptional simple modular Lie superalgebras in characteristic $p\geq 3$, that have appeared in the classification due to Bouarroudj, Grozman and Leites of the Lie superalgebras with indecomposable symmetrizable Cartan matrices, are provided. The models relate these exceptional Lie superalgebras to some low dimensional nonassociative algebraic

Josep Gonzalez, Jordi Guardia

We describe a method to determine all the isomorphism classes of principal polarizations of the modular abelian surfaces $A_f$ with quaternionic multiplication attached to a normalized newform $f$ without complex multiplication. We include an example of $A_f$ with quaternionic multiplication for which we find numerically a curve $C$ whose Jacobian is $A_f$ u

Lin Dai, Tony T. Lee

This paper studies the network throughput and transport delay of a multihop wireless random access network based on a Markov renewal model of packet transportation. We show that the distribution of the source-to-destination (SD) distance plays a critical role in characterizing network performance. We establish necessary and sufficient condition on the SD dis

T. Watanabe, M. Oosawa, K. Saito, S. Oryu

A new approach based on antisymmetrized molecular dynamics is proposed to correctly take account of the many-body correlation. We applied it to the spectra of low-lying, light and strange baryons. The inclusion of the quark-quark correlation is vital to predict the precise spectra, and the semi-relativistic kinematics is also important to correct the level o

Christoph Schommer

In this paper, we informally introduce dynamic mind-maps that represent a new approach on the basis of a dynamic construction of connectionist structures during the processing of a data stream. This allows the representation and processing of recursively defined structures and avoids the problem of a more traditional, fixed-size architecture with the process

N-A P Nicorovici, R C McPhedran, S Enoch, G Tayeb

We consider cloaking by a coated cylindrical system using plasmonic resonance, and extend previous quasistatic treatments to include the effect of finite wavelength. We show that a probe cylinder can still be cloaked at finite wavelengths, but the cloaking cylinder develops a non-zero scattering cross-section. We show that this latter effect is dominated by

Martin Ziegler

We turn `the' Church-Turing Hypothesis from an ambiguous source of sensational speculations into a (collection of) sound and well-defined scientific problem(s): Examining recent controversies, and causes for misunderstanding, concerning the state of the Church-Turing Hypothesis (CTH), suggests to study the CTH relative to an arbitrary but specific physic

R. Barnard, L. Shaw Greening, U. Kolb

NGC 253 is a local, star-bursting spiral galaxy with strong X-ray emission from hot gas, as well as many point sources. We have conducted a spectral survey of the X-ray population of NGC 253 using a deep XMM-Newton observation.NGC 253 only accounts for ~20% of the XMM-Newton EPIC field of view, allowing us to identify ~100 X-ray sources that are unlikely to

Vasile V. Morariu

The mean length and the variability of coding sequences for 48 genomes of bacteria and archaea were analyzed. It was found that the plotted data can be described by an angular area. This suggests the followings: a) The variability of a genome increases as the mean length increases; b) There is an upper and a lower limit for variability for a given mean lengt

H. Owladeghaffari, K. Shahriar, G. H. R. Saeedi

Approximately more than 90% of all coal production in Iranian underground mines is derived directly longwall mining method. Out of seam dilution is one of the essential problems in these mines. Therefore the dilution can impose the additional cost of mining and milling. As a result, recognition of the effective parameters on the dilution has a remarkable rol

Roman Cherniha, Oleksii Pliukhin

A wide range of new Q-conditional symmetries for reaction-diffusion systems with power diffusivities are constructed. The relevant non-Lie ansatze to reduce the reaction-diffusion systems to ODE systems and examples of exact solutions are obtained. The relation of the solutions obtained with the development of spatially inhomogeneous structures is discussed.

P Laurent, J F Fagnard, B Vanderheyden, N Hari Babu

The main purpose of this work was to design, develop and construct a simple, low-cost AC susceptometer to measure large, bulk superconducting samples (up to 32 mm in diameter) in the temperature range 78-120 K. The design incorporates a double heating system that enables a high heating rate (25 K/hour) while maintaining a small temperature gradient (< 0.2 K)

Tulkin H. Rasulov, Mukhiddin I. Muminov, Mahir Hasanov

A model operator $H$ associated to a system describing four particles in interaction, without conservation of the number of particles, is considered. We describe the essential spectrum of $H$ by the spectrum of the channel operators and prove the Hunziker-van Winter-Zhislin (HWZ) theorem for the operator $H.$ We also give some variational principles for boun

T. Hovatta, E. Nieppola, M. Tornikoski, E. Valtaoja

We have studied the flare characteristics of 55 AGN at 8 different frequency bands between 4.8 and 230 GHz. Our extensive database enables us to study the various observational properties of flares in these sources and compare our results with theoretical models. We visually extracted 159 individual flares from the flux density curves and calculated differen

A. Yamamoto, J. Jiang, C. Tarantini, N. Craig

The new rare-earth arsenate superconductors are layered, low carrier density compounds with many similarities to the high-Tc cuprates. An important question is whether they also exhibit weak-coupling across randomly oriented grain-boundaries. In this work we show considerable evidence for such weak-coupling by study of the dependence of magnetization in bulk

Yidong Sun, Zhiping Wang

In this paper, the problem of pattern avoidance in generalized non-crossing trees is studied. The generating functions for generalized non-crossing trees avoiding patterns of length one and two are obtained. Lagrange inversion formula is used to obtain the explicit formulas for some special cases. Bijection is also established between generalized non-crossin

Yidong Sun

In this short note, we first present a simple bijection between binary trees and colored ternary trees and then derive a new identity related to generalized Catalan numbers.

Yidong Sun

In this note, a new concept called {\em $SDR$-matrix} is proposed, which is an infinite lower triangular matrix obeying the generalized rule of David star. Some basic properties of $SDR$-matrices are discussed and two conjectures on $SDR$-matrices are presented, one of which states that if a matrix is a $SDR$-matrix, then so is its matrix inverse (if exists)

Toufik Mansour, Yidong Sun

In this paper we enumerate the number of ways of selecting $k$ objects from $n$ objects arrayed in a line such that no two selected ones are separated by $m-1,2m-1,...,pm-1$ objects and provide three different formulas when $m,p\geq 1$ and $n\geq pm(k-1)$. Also, we prove that the number of ways of selecting $k$ objects from $n$ objects arrayed in a circle su

Toufik Mansour, Yidong Sun

We first establish the result that the Narayana polynomials can be represented as the integrals of the Legendre polynomials. Then we represent the Catalan numbers in terms of the Narayana polynomials by three different identities. We give three different proofs for these identities, namely, two algebraic proofs and one combinatorial proof. Some applications

Toufik Mansour, Yidong Sun

A {\em k-generalized Dyck path} of length $n$ is a lattice path from $(0,0)$ to $(n,0)$ in the plane integer lattice $\mathbb{Z}\times\mathbb{Z}$ consisting of horizontal-steps $(k, 0)$ for a given integer $k\geq 0$, up-steps $(1,1)$, and down-steps $(1,-1)$, which never passes below the x-axis. The present paper studies three kinds of statistics on $k$-gene

Yidong Sun, Huajun Zhang

In this paper, we define two kinds of hook length for internal vertices of complete $m$-ary trees, and deduce their corresponding hook length formulas, which generalize the main results obtained by Du and Liu.

Deepak K Gupta, Raymond J Fonck, George R McKee, David J Schlossberg

An upgraded Beam Emission Spectroscopy (BES) system has been deployed to access low amplitude turbulence regions near internal transport barriers on the DIII-D tokamak. Sixteen high sensitivity channels are being installed. A significant increase in total signal to noise is achieved by: 1.) Increased spatial volume sampling tailored to known turbulence chara

Wenguang Zhai

Let $Δ(x)$ be the error term of the Dirichlet divisor problem. The asymptotic formula of the integral $\int_1^TΔ^k(x)dx$ is established for any integer $3\leq k\leq 9$ by an unified method. Similar results are also established for some other well-known error terms in the analytic number theory.

K. Kaneko, Y. Sun, M. Hasegawa, T. Mizusaki

Using a shell model which is capable of describing the spectra of upper $g_{9/2}$-shell nuclei close to the $N=Z$ line, we study the structure of two isomeric states $7^{+}$ and $21^{+}$ in the odd-odd $N=Z$ nucleus $^{94}$Ag. It is found that both isomeric states exhibit a large collectivity. The $7^{+}$ state is oblately deformed, and is suggested to be a

Vincenzo F. Cardone, Rolando P. Cardenas, Yoelsy Leiva Nodal

In order to solve the problem of eternal acceleration, a model has been recently proposed including both a negative cosmological constant $Λ$ and a scalar field evolving under the action of an exponential potential. We further explore this model by contrasting it against the Hubble diagram of Type Ia supernovae, the gas mass fraction in galaxy clusters and t

S. Ghose, R. Stock, P. S. Jessen, R. Lal

We analyze the interplay of chaos, entanglement and decoherence in a system of qubits whose collective behaviour is that of a quantum kicked top. The dynamical entanglement between a single qubit and the rest can be calculated from the mean of the collective spin operators. This allows the possibility of efficiently measuring entanglement dynamics in an expe

Hajime Susa

We perform radiation hydrodynamics simulations on the evolution of galactic gas disks irradiated by ultraviolet radiation background. We find gas disks with N_H > 10^21 cm^-2 exposed to ultraviolet radiation at a level of I_21=1 can be self-shielded from photoheating, whereas the disk with N_H < 10^21 cm^-2 cannot. We also find that the unshielded disks keep

Youngchul Sung, H. Vincent Poor, Heejung Yu

The problem of optimal node density for ad hoc sensor networks deployed for making inferences about two dimensional correlated random fields is considered. Using a symmetric first order conditional autoregressive Gauss-Markov random field model, large deviations results are used to characterize the asymptotic per-node information gained from the array. This

W. R. G. James, I. Jensen, A. J. Guttmann

Polygons are described as almost-convex if their perimeter differs from the perimeter of their minimum bounding rectangle by twice their `concavity index&#39;, $m$. Such polygons are called \emph{$m$-convex} polygons and are characterised by having up to $m$ indentations in their perimeter. We first describe how we conjectured the (isotropic) generating func

Hans Lundmark, Jacek Szmigielski

We study a class of piecewise linear solutions to the inviscid Burgers equation driven by a linear forcing term. Inspired by the analogy with peakons, we think of these solutions as being made up of solitons situated at the breakpoints. We derive and solve ODEs governing the soliton dynamics, first for continuous solutions, and then for more general shock wa

Gaston Giribet, Yu Nakayama, Lorena Nicolas

We show a physical realization of the Langlands duality in correlation functions of H_3^+ WZNW model. We derive a dual version of the Stoyanovky-Riabult-Teschner (SRT) formula that relates the correlation function of the H_3^+ WZNW and the dual Liouville theory to investigate the level duality k-2 \to (k-2)^{-1} in the WZNW correlation functions. Then, we sh

Wei-Zhou Jiang, Bao-An Li

Within the relativistic Hartree approach using a Lagrangian with density-dependent parameters respecting the chiral limit, it is found that the vacuum corrections from the nucleon Dirac sea soften the equation of state and favor the chiral symmetry restoration at high densities.

Sam Payne

We show that lattice polytopes cut out by root systems of classical type are normal and Koszul, generalizing a well-known result of Bruns, Gubeladze, and Trung in type A. We prove similar results for Cayley sums of collections of polytopes whose Minkowski sums are cut out by root systems. The proofs are based on a combinatorial characterization of diagonally

Kristin Chiboucas, Igor D. Karachentsev, R. Brent Tully

An order of magnitude more dwarf galaxies are expected to inhabit the Local Group, based on currently accepted galaxy formation models, than have been observed. This discrepancy has been noted in environments ranging from the field to rich clusters. However, no complete census of dwarf galaxies exist in any environment. The discovery of the smallest and fain

Thomas P. Sotiriou, Valerio Faraoni

We consider alternative theories of gravity with a direct coupling between matter and the Ricci scalar We study the relation between these theories and ordinary scalar-tensor gravity, or scalar-tensor theories which include non-standard couplings between the scalar and matter. We then analyze the motion of matter in such theories, its implications for the Eq

J. Diemand, M. Kuhlen, P. Madau, M. Zemp

In cold dark matter cosmological models, structures form and grow by merging of smaller units. Numerical simulations have shown that such merging is incomplete; the inner cores of halos survive and orbit as &#34;subhalos&#34; within their hosts. Here we report a simulation that resolves such substructure even in the very inner regions of the Galactic halo. W

Michiel P. Sanders

The only place in the world where at this time standard model Higgs bosons can be produced and detected is the Tevatron at Fermilab. In this contribution, the most recent results on the search for a low mass Higgs boson are presented, using datasets of up to 1.9 fb-1. In the absence of signal, the combined Tevatron cross section limit at a Higgs boson mass o

Abouzeid. M. Shalaby

In this work, we investigate a very important but unstressed result in the work of Carl M. Bender, Jun-Hua Chen, and Kimball A. Milton ( J.Phys.A39:1657-1668, 2006). In this article, Bender \textit{et.al} have calculated the vacuum energy of the $iϕ^{3}$ scalar field theory and its Hermitian equivalent theory up to $g^{4}$ order of calculations. While all th

Vikram Chandrasekhar, Jeffrey G. Andrews

Two-tier networks, comprising a conventional cellular network overlaid with shorter range hotspots (e.g. femtocells, distributed antennas, or wired relays), offer an economically viable way to improve cellular system capacity. The capacity-limiting factor in such networks is interference. The cross-tier interference between macrocells and femtocells can suff

Matthew Nguyen

Jet tomography, the study of differential energy loss of hard scattered partons to infer the density profile of the medium, is greatly improved by precise knowledge of the initial energy of the hard probe. As photons are not strongly interacting, the momentum of the recoil jet from a direct photon trigger is balanced, to a good approximation, by the momentum

O. Bertolami, J. Páramos

The connection between $f(R)$ theories of gravity and scalar-tensor models with a &#34;physical&#34; metric coupled to the scalar field is well known. In this work, we pursue the equivalence between a suitable scalar theory and a model that generalises the $f(R)$ scenario, encompassing both a non-trivial scalar curvature term and a non-minimum coupling of th

David Benson, Stephen Doty

We prove a version of Schur--Weyl duality over finite fields. We prove that for any field $k$, if $k$ has at least $r+1$ elements, then Schur--Weyl duality holds for the $r$th tensor power of a finite dimensional vector space $V$. Moreover, if the dimension of $V$ is at least $r+1$, the natural map $k\Sym_r \to End\_{GL(V)}(V^{\otimes r})$ is an isomorphism.

Tsz Yan Lam, Ravi K. Sheth

We use the physics of ellipsoidal collapse to model the probability distribution function of the smoothed dark matter density field in real and redshift space. We provide a simple approximation to the exact collapse model which shows clearly how the evolution can be thought of as a modification of the spherical evolution model as well as of the Zeldovich App

Daniel Reitzner, Mark Hillery, Edgar Feldman, Vladimir Buzek

We study scattering quantum walks on highly symmetric graphs and use the walks to solve search problems on these graphs. The particle making the walk resides on the edges of the graph, and at each time step scatters at the vertices. All of the vertices have the same scattering properties except for a subset of special vertices. The object of the search is to

Sam R. Dolan

The scattering cross section for a long-wavelength planar gravitational wave impinging upon a rotating black hole is calculated, for the special case in which the direction of incidence is aligned with the rotation axis. We show that black hole rotation leads to a term in the cross section that is proportional to $aω$. Hence, contrary to some claims, co-rota

Stefan Friedl, Stefano Vidussi

A classical result in knot theory says that the Alexander polynomial of a fibered knot is monic and that its degree equals twice the genus of the knot. This result has been generalized by various authors to twisted Alexander polynomials and fibered 3-manifolds. In this paper we show that the conditions on twisted Alexander polynomials are not only necessary

Ramin A. Skibba

Current analytic and semi-analytic dark matter halo models distinguish between the central galaxy in a halo and the satellite galaxies in halo substructures. Using a recent halo-model description of the color dependence of galaxy clustering (Skibba & Sheth 2008), we investigate the colors of central and satellite galaxies predicted by the model and compare t

Hirotaka Hayashi, Radu Tatar, Yukinobu Toda, Taizan Watari

In order to understand both up-type and down-type Yukawa couplings, F-theory is a better framework than the perturbative Type IIB string theory. The duality between the Heterotic and F-theory is a powerful tool in gaining more insights into F-theory description of low-energy chiral multiplets. Because chiral multiplets from bundles /\^2 V and /\^2 V^x as wel

Thomas P. Sotiriou

Recently there has been a proposal for modified gravitational f(R) actions which include a direct coupling between the matter action and the Ricci scalar, R. Of particular interest is the specific case where both the action and the coupling are linear in R. It is shown that such an action leads to a theory of gravity which includes higher order derivatives o

Stephan Foldes

Finite Lorentz groups acting on 4-dimensional vector spaces coordinatized by finite fields with a prime number of elements are represented as homomorphic images of countable, rational subgroups of the Lorentz group acting on real 4-dimensional space-time. Bounded subsets of the real Lorentz group are retractable with arbitrary accuracy to finite subsets of s

Saumen Datta, Peter Petreczky

We calculate the low energy contribution to quarkonium correlators in Euclidean time in lattice QCD. This contribution was found to give the dominant source of the temperature dependence of the correlators. We have found that the low energy contribution is well described by a quasi-particle model and have determined the effective temperature dependent heavy

Yanou Cui, David E. Morrissey

Cosmic strings can be created in the early universe during symmetry-breaking phase transitions, such as might arise if the gauge structure of the standard model is extended by additional U(1) factors at high energies. Cosmic strings present in the early universe form a network of long horizon-length segments, as well as a population of closed string loops. T

Jo Bovy, David W. Hogg, John Moustakas

If galaxy clusters contain intracluster dust, the spectra of galaxies lying behind clusters should show attenuation by dust absorption. We compare the optical (3500 - 7200 Å) spectra of 60,267 luminous, early-type galaxies selected from the Sloan Digital Sky Survey to search for the signatures of intracluster dust in z ~ 0.05 clusters. We select massive, qui