April 2008 arXiv papers — page 47

P. Ao

From a logic point of view this is the third in the series to solve the problem of absence of detailed balance. This paper will be denoted as SDS III. The existence of a dynamical potential with both local and global meanings in general nonequilibrium processes has been controversial. Following an earlier explicit construction by one of us (Ao, J. Phys. {\bf

Maitere Aguerrea, Sergei Trofimchuk, Gabriel Valenzuela

We consider positive travelling fronts of the time-delayed reaction-diffusion equation with the monostable birth function. Our main result says that for every fixed and sufficiently large velocity c, the positive travelling front is unique (modulo translations). To prove the uniqueness, we introduce a small parameter 1/c and realize the Lyapunov-Schmidt redu

M. J. van Setten, S. Er, G. Brocks, R. A. de Groot

The optical and electronic properties of Mg-Ti hydrides are studied using first-principles density functional theory. Dielectric functions are calculated for MgxTi(1-x)H2 with compositions x = 0.5, 0.75, and 0.875. The structure is that of fluorite TiH2 where both Mg and Ti atoms reside at the Ti positions of the lattice. In order to assess the effect of ran

S. Lerouge, M. A. Fardin, M. Argentina, G. Gregoire

We report on a non trivial dynamics of the interface between shear bands following a start-up of flow in a semi-dilute wormlike micellar system investigated using a combination of mechanical and optical measurements. During the building of the banding structure, we observed the stages of formation, migration of the interface between bands and finally the des

Michael G. Eastwood, A. Rod Gover

The Midwest Geometry Conference 2007 was devoted to the substantial mathematical legacy of Thomas P. Branson who passed away unexpectedly the previous year. This contribution to the Proceedings briefly introduces this legacy. We also take the opportunity of recording his bibliography. Thomas Branson was on the Editorial Board of SIGMA and we are pleased that

Mark T. Reynolds, Paul J. Callanan, Edward L. Robinson, Cynthia S. Froning

The most widely used means of measuring the mass of black holes in Galactic binaries - specifically the X-ray novae - involves both radial velocity measurements of the secondary star, and photometric measurements of its ellipsoidal variability. The latter is important in constraining the inclination and mass ratio, and requires as direct a measure of the flu

Liliana Teodorescu

Evolutionary Computation is a branch of computer science with which, traditionally, High Energy Physics has fewer connections. Its methods were investigated in this field, mainly for data analysis tasks. These methods and studies are, however, less known in the high energy physics community and this motivated us to prepare this lecture. The lecture presents

Patrick Chénais

While developing an information system for the University of Bern, we were faced with two major issues: managing software changes and adapting Business Information Models. Software techniques well-suited to software development teams exist, yet the models obtained are often too complex for the business user. We will first highlight the conceptual problems en

P. Ziń, B. Oleś, M. Trippenbach, K. Sacha

We consider a homogeneous Bose gas of particles with an attractive interaction. Mean field theory predicts for this system a spontaneous symmetry breaking at a certain value of the interaction strength. We show that at this point a second-order quantum phase transition occurs. We investigate the system in the vicinity of the critical point using Bogoliubov t

Kalpataru Pradhan, Prasenjit Sen, J. Ulises Reveles, Shiv N. Khanna

Geometry, electronic structure, and magnetic properties of TMNan (TM=Cr-Ni; n = 4-7) clusters are studied within a gradient corrected density functional theory (DFT) framework. Two complementary approaches, the first adapted to all-electron calculations on free clusters, and the second been on plane wave projector augmented wave (PAW) method within a superce

N. Jachowicz, G. C. McLaughlin, C. Volpe

Recently, we suggested that low-energy beta-beam neutrinos can be very useful for the study of supernova neutrino interactions. In this paper, we examine the use of a such experiment for the analysis of a supernova neutrino signal. Since supernova neutrinos are oscillating, it is very likely that the terrestrial spectrum of supernova neutrinos of a given fla

H. Owladeghaffari, K. Shahriar W. Pedrycz

This paper pursues some applications of Rough Set Theory (RST) and neural-fuzzy model to analysis of "lugeon data". In the manner, using Self Organizing Map (SOM) as a pre-processing the data are scaled and then the dominant rules by RST, are elicited. Based on these rules variations of permeability in the different levels of Shivashan dam, Iran has

M. Sharifzadeh, H. Owladeghaffari, K. Shahriar, E. Bakhtavar

This paper describes application of information granulation theory, on the analysis of "lugeon data". In this manner, using a combining of Self Organizing Map (SOM) and Neuro-Fuzzy Inference System (NFIS), crisp and fuzzy granules are obtained. Balancing of crisp granules and sub- fuzzy granules, within non fuzzy information (initial granulation), is

G. Trinchieri, A. Iovino, E. Pompei, M. Dahlem

AIMS: Compact groups of galaxies are excellent laboratories for studying galaxy interactions and their effects on the evolution of galaxies. In particular, dynamically young systems, with a large fraction of interacting, late type galaxies, have so far escaped proper studies in the X-ray band and their hot intergalactic medium properties are virtually unknow

T. Binoth, G. Ossola, C. G. Papadopoulos, R. Pittau

We present a calculation of the NLO QCD corrections for the production of three vector bosons at the LHC, namely Z Z Z, W+ W- Z, W+ Z Z, and W+ W- W+ production. The virtual corrections are computed using the recently proposed method of reduction at the integrand level (OPP reduction). Concerning the contributions coming from real emission we used the dipole

G. Pietrzynski, W. Gieren, O. Szewczyk, A. Walker

We have obtained single-phase near-infrared magnitudes in the J and K bands for a sample of 78 RR Lyrae stars in the Sculptor dSph galaxy. Applying different theoretical and empirical calibrations of the period-luminosity-metallicity relation for RR Lyrae stars in the infrared, we find consistent results and obtain a true, reddening-corrected distance modulu

Jakob Mehl, Thomas Speck, Udo Seifert

The large deviation function for entropy production is calculated for a particle driven along a periodic potential by solving a time-independent eigenvalue problem. In an intermediate force regime, the large deviation function shows pronounced deviations from a Gaussian behavior with a characteristic ``kink'' at zero entropy production. Such a featur

S. Markoff, M. Nowak, A. Young, H. L. Marshall

We present the results of a broadband simultaneous campaign on the nearby low-luminosity active galactic nucleus M81*. From February through August 2005, we observed M81* five times using the Chandra X-ray Observatory with the High-Energy Transmission Grating Spectrometer, complemented by ground-based observations with the Giant Meterwave Radio Telescope, th

Francesco De Martini, Fabio Sciarrino, Chiara Vitelli

In recent years two fundamental aspects of quantum mechanics have attracted a great deal of interest, namely the investigation on the irreducible nonlocal properties of Nature implied by quantum entanglement and the physical realization of the 'Schroedinger Cat'. In the present work a macro - state consisting of about 3.5 x 10^4 photons in a quantum

Hajer Bahouri, Isabelle Gallagher

The goal of this paper is to study the action of the heat operator on the Heisenberg group H^d, and in particular to characterize Besov spaces of negative index on H^d in terms of the heat kernel. That characterization can be extended to positive indexes using Bernstein inequalities. As a corollary we obtain a proof of refined Sobolev inequalities in W^{s,p}

Henri Gouin

We propose a new method to study motions of mixtures in fluid interfaces. We extend the equations of equilibrium in interfaces and the results associated with travelling waves for van der Waals like fluids. Maxwell rule is extended to interfaces of fluid mixtures out of equilibrium. Formulae like Clapeyron relation are obtained for isothermal layers.

G. Brodin, M. Marklund

Plasmas are usually described using classical equations. While this is often a good approximation, where are situations when a quantum description is motivated. In this paper we will include several quantum effects, ranging from particle dispersion, which give raise to the so called Bohm potential, to spin effects, and to quantum electrodynamical effects. Th

M. Marklund, G. Brodin

Quantum plasmas is a rapidly expanding field of research, with applications ranging from nanoelectronics, nanoscale devices and ultracold plasmas, to inertial confinement fusion and astrophysics. Here we give a short systematic overview of quantum plasmas. In particular, we analyze the collective effects due to spin using fluid models. The introduction of an

Edward K. Porter, Neil J. Cornish

Massive black hole binaries are key targets for the space based gravitational wave interferometer LISA. Several studies have investigated how LISA observations could be used to constrain the parameters of these systems. Until recently, most of these studies have ignored the higher harmonic corrections to the waveforms. Here we analyze the effects of the high

Attilio L. Stella, Fulvio Baldovin

Modeling the evolution of a financial index as a stochastic process is a problem awaiting a full, satisfactory solution since it was first formulated by Bachelier in 1900. Here it is shown that the scaling with time of the return probability density function sampled from the historical series suggests a successful model. The resulting stochastic process is a

Gerard 't Hooft

Matter interacting classically with gravity in 3+1 dimensions usually gives rise to a continuum of degrees of freedom, so that, in any attempt to quantize the theory, ultraviolet divergences are nearly inevitable. Here, we investigate matter of a form that only displays a finite number of degrees of freedom in compact sections of space-time. In finite domain

Dirk Hofmann

Our work over the past years shows that not only the collection of (for instance) all topological spaces gives rise to a category, but also each topological space can be seen individually as a category by interpreting the convergence relation $\mathfrak{x}\to x$ between ultrafilters and points of a topological space $X$ as arrows in $X$. Naturally, this poin

Rakesh Kumar, C. V. Tomy, P. L. Paulose, R. Nagarajan

Anomalous magnetic and transport properties observed in the La0.8-xEuxSr0.2MnO3 (0.04 l.e x l.e. 0.36) compounds are presented in this paper. The Curie temperature (TC) decreases from 260 K for x = 0.04 to 188 K for x = 0.16 and surprisingly thereafter increases for higher Eu concentrations (x > 0.16) and becomes nearly constant ~230 K. Resistivity increases

Till Bargheer, Niklas Beisert, Nikolay Gromov

Highly spinning classical strings on RxS^3 are described by the Landau-Lifshitz model or equivalently by the Heisenberg ferromagnet in the thermodynamic limit. The spectrum of this model can be given in terms of spectral curves. However, it is a priori not clear whether any given admissible spectral curve can actually be realised as a solution to the discret

Shinji Kuroda, Nozomi Nishizawa, Koki Takita, Masanori Mitome

The extensive experimental and computational search for multifunctional materials has resulted in the development of semiconductor and oxide systems, such as (Ga,Mn)N, (Zn,Cr)Te, and HfO2, which exhibit surprisingly stable ferromagnetic signatures despite having a small or nominally zero concentration of magnetic elements. Here, we show that the ferromagneti

Tobias Kretz, Michael Schreckenberg

In any spatially discrete model of pedestrian motion which uses a regular lattice as basis, there is the question of how the symmetry between the different directions of motion can be restored as far as possible but with limited computational effort. This question is equivalent to the question ''How important is the orientation of the axis of discret

Maurice HT Ling, Christophe Lefevre, Kevin R. Nicholas

A recent study reported development of Muscorian, a generic text processing tool for extracting protein-protein interactions from text that achieved comparable performance to biomedical-specific text processing tools. This result was unexpected since potential errors from a series of text analysis processes is likely to adversely affect the outcome of the en

D. M. Gaitonde

We consider a moving vortex in a two dimensional superconductor located at a distance $d$ from a metallic overlayer. Starting from the microscopic imaginary time action we integrate out the electronic degrees of freedom to obtain a low energy, long wavelength effective action for the vortex. We focus our attention on the vortex kinetic energy and derive a ge

Gautami Bhowmik, Immanuel Halupczok, Jan-Christoph Schlage-Puchta

Let A be a zero-sum free subset of Z_n with |A|=k. We compute for k\le 7 the least possible size of the set of all subset-sums of A.

D. Heiss, V. Jovanov, M. Bichler, G. Abstreiter

We propose an all optical spin initialization and readout concept for single self assembled quantum dots and demonstrate its feasibility. Our approach is based on a gateable single dot photodiode structure that can be switched between charge and readout mode. After optical electron generation and storage, we propose to employ a spin-conditional absorption of

Rainer Buckdahn, Juan Li

In this paper we investigate zero-sum two-player stochastic differential games whose cost functionals are given by doubly controlled reflected backward stochastic differential equations (RBSDEs) with two barriers. For admissible controls which can depend on the whole past and so include, in particular, information occurring before the beginning of the game,

M. S. Golovkov, L. V. Grigorenko, G. M. Ter-Akopian, A. S. Fomichev

The low-lying spectra of $^8$He and $^{10}$He nuclei were studied in the $^3$H($^6$He,$p$)$^8$He and $^3$H($^8$He,$p$)$^{10}$He transfer reactions. The $0^+$ ground state (g.s.) of $^8$He and excited states, $2^+$ at $3.6-3.9$ MeV and $(1^+)$ at $5.3-5.5$ MeV, were populated with cross sections of 200, 100-250, and 90-125 $μ$b/sr, respectively. Some evidence

J. A. Oller, L. Roca

We perform a theoretical study based on dispersion relations of the reaction γγ\to π^0π^0 emphasizing the low energy region. We discuss how the f_0(980) signal emerges in γγ\to ππwithin the dispersive approach and how this fixes to a large extent the phase of the isoscalar S-wave γγ\to ππamplitude above the K\bar{K} threshold. This allows us to make sharper

Lorenzo Zaninetti, Mario Ferraro

The Pareto probability distribution is widely applied in different fields such us finance, physics, hydrology, geology and astronomy. This note deals with an application of the Pareto distribution to astrophysics and more precisely to the statistical analysis of mass of stars and of diameters of asteroids. In particular a comparison between the usual Pareto

Dastgeer Shaikh, G. P. Zank, N. Pogorelov

The problem of hydrogen neutrals interacting with the heliospheric bow shock region has received considerable attention recently, motivated primarily by the hope that the Voyager spacecraft may soon encounter the first of the heliospheric boundaries. The complexity of the charge exchange interactions has limited our analytic understanding so far. In this wor

Igor A. Tanski

Fundamental solution of degenerated Fokker - Planck equation is built by means of the Fourier transform method. The result is checked by direct calculation.

Z. Brzezniak, J. M. A. M. van Neerven, M. C. Veraar, L. Weis

Using the theory of stochastic integration for processes with values in a UMD Banach space developed recently by the authors, an Ito formula is proved which is applied to prove the existence of strong solutions for a class of stochastic evolution equations in UMD Banach spaces. The abstract results are applied to prove regularity in space and time of the sol

D. Pierini, S. Zibetti, F. Braglia, H. Boehringer

[Abridged] We searched for diffuse stellar emission around BCGs in three of the most X-ray luminous clusters found at z~0.3 in the REFLEX cluster survey and observed with XMM-Newton. These systems (RXCJ0014.3-3022, RXCJ0232.2-4420, and RXCJ2308.3-0211) are in different dynamical states, as witnessed by their X-ray morphology and optical appearence (e.g. mult

Tamiaki Yoneya

I discuss my recent attempt in search of a new framework for quantum field theory of D branes. After explaining some motivations in the background of this project, I present, as a first step towards our goal, a second-quantized reformulation of the U(N) Yang-Mills quantum mechanics in which the D0-brane creation-and-annihilation fields connecting theories wi

Ryota Honda, Shougo Yamagishi, Nobuyuki Kanda, TAMA collaboration

We have developed a method 'time-frequency (TF) clustering' to find the burst gravitational waves for TAMA data analysis. TF clustering method on sonogram (spectrogram) shows some characteristics of short duration signal. Using parameters which represent the cluster shape, we can efficiently identify some predicted gravitational wave forms and can ex

Sijie Gao, José P. S. Lemos

The problem of a spherically symmetric charged thin shell of dust collapsing gravitationally into a charged Reissner-Nordström black hole in $d$ spacetime dimensions is studied within the theory of general relativity. Static charged shells in such a background are also analyzed. First a derivation of the equation of motion of such a shell in a $d$-dimensiona

Yuki Fuseya, Masao Ogata

Response functions for spin-density-wave (SDW) and d-wave singlet superconductivity ($d$SC) in quasi-one-dimensional (Q1D) electron systems are calculated by a renormalization group technique. It is shown that the response functions for both SDW, $χ_\rs$, and $d$SC, $χ_d$, are enhanced by interchain hopping, $t_\perp$, i.e., by quasi-one dimensionality. When

Bertrand Meyer

This paper explores the study of the general Hermite constant associated to the general linear group and its irreducible representations, as defined by T. Watanabe. To that end, a height, which naturally applies to flag varieties, is built and notions of perfection and eutaxy characterising extremality are introduced. Finally we acquaint some relations (e.g.

J. Echevarria, R. Connon Smith, R. Costero, S. Zharikov

High-dispersion time-resolved spectroscopy of the unique magnetic cataclysmic variable AE Aqr is presented. A radial velocity analysis of the absorption lines yields K_2 = 168.7+/- 1 km/s. Substantial deviations of the radial velocity curve from a sinusoid are interpreted in terms of intensity variations over the secondary star's surface. A complex rotat

Malay Bandyopadhyay

The quantum thermodynamic behaviour of a charged oscillator in the presence of a magnetic field and coupled to a heat bath through different coupling schemes is obtained analytically. It is shown that finite dissipation substitutes the zero-coupling result of exponential decay of entropy by a power law behaviour at low temperature. For the coordinate-coordin

Narutaka Ozawa

We prove that the group-measure-space von Neumann algebra $L^\infty(T^2) \rtimes SL(2,Z)$ is solid. The proof uses topological amenability of the action of $SL(2,Z)$ on the Higson corona of $Z^2$.

Sanjay M. Wagh

General Principle of Relativity unequivocally supports the notion of momentum-less energy for bodies (energy-quanta) moving at the {\em same} or {\em constant} speed relative to all the reference systems. In this communication, we point out that whether energy-quantum is a momentum-less body or not is verifiable using ultra-cold atoms trapped in an optical l

Masashi Chiba, Takeo Minezaki, Kaiki T. Inoue, Nobunari Kashikawa

To set useful limits on the abundance of small-scale dark matter halos (subhalos) in a galaxy scale, we have carried out mid-infrared imaging and integral-field spectroscopy for a sample of quadruple lens systems showing anomalous flux ratios. These observations using Subaru have been successful for distinguishing millilensing by subhalos from microlensing b

Chao Cao, Yi-Xin Chen, Jian-Long Li

We study the property of matter in equilibrium with a static, spherically symmetric black hole in D-dimensional spacetime. It requires this kind of matter has an equation of state (\omega\equiv p_r/\rho=-1/(1+2kn), k,n\in \mathbb{N}), which seems to be independent of D. However, when we associate this with specific models, some interesting limits on space co

Jonathan R. McDonald, Warner A. Miller

In 1961 Tullio Regge provided us with a beautiful lattice representation of Einstein's geometric theory of gravity. This Regge Calculus (RC) is strikingly different from the more usual finite difference and finite element discretizations of gravity. In RC the fundamental principles of General Relativity are applied directly to a tessellated spacetime geo

Loris P. L. Colombo, Elena Pierpaoli

On large angular scales, CMB polarization depends mostly on the evolution of the ionization level of the IGM during reionization. In order to avoid biasing parameter estimates, an accurate and model independent approach to reionization is needed when analyzing high precision data, like those expected from the Planck experiment. In this paper we consider two

Marko A. Rodriguez

There exists an injective, information-preserving function that maps a semantic network (i.e a directed labeled network) to a directed network (i.e. a directed unlabeled network). The edge label in the semantic network is represented as a topological feature of the directed network. Also, there exists an injective function that maps a directed network to an

Nodar L. Tsintsadze, Levan N. Tsintsadze

A general derivation of the charging equation of a dust grain is presented, and indicated where and when it can be used. A problem of linear fluctuations of charges on the surface of the dust grain is discussed.

I. Krichever, T. Shiota

We introduce the notion of abelian solutions of KP equations and show that all of them are algebro-geometric.

B. P. Lanyon, M. Barbieri, M. P. Almeida, T. Jennewein

Quantum computation offers the potential to solve fundamental yet otherwise intractable problems across a range of active fields of research. Recently, universal quantum-logic gate sets - the building blocks for a quantum computer - have been demonstrated in several physical architectures. A serious obstacle to a full-scale implementation is the sheer number

Steven Verpoort

The object of study of this article is compact surfaces in the three-dimensional hyperbolic space with a positive-definite second fundamental form. It is shown that several conditions on the Gaussian curvature of the second fundamental form can be satisfied only by extrinsic spheres.

J. R. Rizzo, F. M. Jimenez-Esteban, E. Ortiz

We present for the first time the detection of mid-J CO line emission in the outskirts of an evolved massive star, which indicates the presence of warm and/or high density molecular gas. Aiming to learn about the interplay between evolved massive stars and their surroundings, we have carried out CO J=2-1, J=3-2, and (13)CO J=2-1 line observations in a 4'

Agissilaos G. Athanassoulis, Norbert J. Mauser, Thierry Paul

Smoothed Wigner transforms have been used in signal processing, as a regularized version of the Wigner transform, and have been proposed as an alternative to it in the homogenization and / or semiclassical limits of wave equations. We derive explicit, closed formulations for the coarse-scale representation of the action of pseudodifferential operators. The r

Judy Day, Jonathan Rubin, Carson C. Chow

Dynamical systems studies of differential equations often focus on the behavior of solutions near critical points and on invariant manifolds, to elucidate the organization of the associated flow. In addition, effective methods, such as the use of Poincare maps and phase resetting curves, have been developed for the study of periodic orbits. However, the anal

Frank Ferrari

We give a brief account of the recent progresses in super Yang-Mills theories based in particular on the application of Nekrasov's instanton technology to the case of N=1 supersymmetry. We have developed a first-principle formalism from which any chiral observable in the theory can be computed, including in strongly coupled confining vacua. The correlato

Wesley C. Campbell, Timur V. Tscherbul, Hsin-I Lu, Edem Tsikata

We measure and theoretically determine the effect of molecular rotational splitting on Zeeman relaxation rates in collisions of cold Triplet-Sigma molecules with helium atoms in a magnetic field. All four stable isotopomers of the imidogen (NH) molecule are magnetically trapped and studied in collisions with 3He and 4He. The 4He data support the predicted in

Pedro F. dos Santos, Zhaohu Nie

Let $G$ be a finite group. For a based $G$-space $X$ and a Mackey functor $M$, a topological Mackey functor $X\widetilde\otimes M$ is constructed, which will be called the stable equivariant abelianization of $X$ with coefficients in $M$. When $X$ is a based $G$-CW complex, $X\widetilde\otimes M$ is shown to be an infinite loop space in the sense of $\mathca

Atilla Yilmaz

We take the point of view of a particle performing random walk with bounded jumps on $\mathbb{Z}^d$ in a stationary and ergodic random environment. We prove the quenched large deviation principle (LDP) for the pair empirical measure of the environment Markov chain. By an appropriate contraction, we deduce the quenched LDP for the mean velocity of the particl

Rafael A. Porto, Ira Z. Rothstein

Using effective field theory techniques we compute the next to leading order Spin(1)Spin(1) terms in the potential of spinning compact objects at third Post-Newtonian order, including sub-leading self-induced finite size effects. This result represents the last ingredient to complete the relevant spin potentials to 3PN order from which the equations of motio

Jinfeng Liao, Edward Shuryak

The so called magnetic scenario recently suggested in \cite{Liao_ES_mono} emphasizes the role of monopoles in strongly coupled quark-gluon plasma (sQGP) near/above the deconfinement temperature, and specifically predicts that they help reduce its viscosity by the so called "magnetic bottle" effect. Arguments for "magnetic liquid" in 1-2$T_c$

Jun Ye, H. J. Kimble, Hidetoshi Katori

Precision metrology and quantum measurement often demand matter be prepared in well defined quantum states for both internal and external degrees of freedom. Laser-cooled neutral atoms localized in a deeply confining optical potential satisfy this requirement. With an appropriate choice of wavelength and polarization for the optical trap, two electronic stat

Adel B. Badi

We prove an index theorem for Toeplitz operators on the quarter-plane using the index theory for generalized Toeplitz operators introduced by G. J. Murphy. To prove this index theorem we construct an indicial triple on the tensor product of two C*-algebras provided with indicial triples with general conditions. We show that our results can be extended to som

Cecilia Cormick, Juan Pablo Paz

We study the evolution of a system of two qubits, each of which interacts locally with a spin chain with nontrivial internal Hamiltonian. We present an exact solution to this problem and analyze the dependence of decoherence on the distance between the interaction sites. In the strong coupling regime we find that decoherence increases with increasing distanc

S. M. Natanzon

It is investigated Hurwitz numbers, that correspond to covering of disk with single non-simple boundary critical value. It is found differential equations, that describe a generating function for these numbers.

Christian D. Ott, Adam Burrows, Luc Dessart, Eli Livne

We perform axisymmetric (2D) multi-angle, multi-group neutrino radiation-hydrodynamic calculations of the postbounce phase of core-collapse supernovae using a genuinely 2D discrete-ordinate (S_n) method. We follow the long-term postbounce evolution of the cores of one nonrotating and one rapidly-rotating 20-solar-mass stellar model for ~400 milliseconds from

R. C. Reis, A. C. Fabian, R. Ross, G. Miniutti

We present a systematic study of GX 339-4 in both its very high and low hard states from simultaneous observations made with XMM-Newton and RXTE in 2002 and 2004. The X-ray spectra of both these extreme states exhibit strong reflection signatures, with a broad, skewed Fe-Kalpha line clearly visible above the continuum. Using a newly developed, self-consisten

J. Farihi, E. E. Becklin, B. Zuckerman

This paper presents a sensitive and comprehensive IRAC 3-8 $μ$m photometric survey of white dwarfs for companions in the planetary mass regime with temperatures cooler than the known T dwarfs. The search focuses on descendents of intermediate mass stars with $M\ga3$ $M_{\odot}$ whose inner, few hundred AU regions cannot be probed effectively for massive plan

J. -H. Woo, T. Treu, M. A. Malkan, R. Blandford

We measure the evolution of the correlation between black hole mass and host spheroid velocity dispersion over the last 6 billion years, by studying three carefully selected samples of active galaxies at z=0.57, z=0.36 and z<0.1. For all three samples, virial black hole masses are consistently estimated using the line dispersion of H$β$ and the continuum lum

Richard Lieu

In any Big Bang cosmology, the frequency $ω$ of light detected from a distant source is continuously and linearly changing (usually redshifting) with elapsed observer&#39;s time $δt$, because of the expanding Universe. For small $δt$, however, the resulting $δω$ shift lies beneath the Heisenberg frequency uncertainty. And since there {\it is} a way of tellin

Wei Liu

In preparation for an experimental study of magnetorotational instability (MRI) in liquid metal, we present non-ideal axisymmetric magnetohydrodynamic simulations of the nonlinear evolution of MRI in the experimental geometry. The simulations adopt fully insulating boundary conditions. No-slip conditions are imposed at the cylinders. A clear linear phase is

Daniela Bertacchi, Fabio Zucca

We study the branching random walk on weighted graphs; site-breeding and edge-breeding branching random walks on graphs are seen as particular cases. We describe the strong critical value in terms of a geometrical parameter of the graph. We characterize the weak critical value and relate it to another geometrical parameter. We prove that, at the strong criti

E. Villagran, J. Socorro, Ricardo Garcia-Salcedo, M. Aguero

In the present work, we study, by means of a one-dimensional lattice model, the collective excitations corresponding to intra molecular ones of a chain like proteins. It is shown that such excitations are described by the Nonlinear Schrodinger equation with saturation. The solutions obtained here are the bell solitons, bubbles, kinks and crowdons. Since they

Matias dell&#39;Erba, Guillermo R. Zemba

We analyze the thermodynamic properties of a simplified model for folded RNA molecules recently studied by G. Vernizzi, H. Orland, A. Zee (in {\it Phys. Rev. Lett.} {\bf 94} (2005) 168103). The model consists of a chain of one-flavor base molecules with a flexible backbone and all possible pairing interactions equally allowed. The spatial pseudoknot structur

V. V. Begun, M. Gaździcki, M. I. Gorenstein

Volume fluctuations are introduced in a statistical modelling of relativistic particle collisions. The micro-canonical ensemble is used, and the volume fluctuations are assumed to have the specific scaling properties. This leads to the KNO scaling of the particle multiplicity distributions as measured in p+p interactions. A striking prediction of the model i

Thomas G. Rizzo

If the LHC discovers a $Z&#39;$-like state the extraction of its couplings to the particles of the Standard Model becomes mandatory in order to determine the nature of the underlying new physics theory. It has been well-known for some time that the direct measurements performed at the LHC in the Drell-Yan channel cannot determine these parameters uniquely in

Flora Lopis, Max Tegmark

Was Einstein wrong? This paper provides a detailed technical review of Einstein&#39;s special and general relativity from an astrophysical perspective, including the historical development of the theories, experimental tests, modern applications to black holes, cosmology and parallel universes, and last but not least, novel ways of expressing their seven mos

Markus Tiersch, Fernando de Melo, Andreas Buchleitner

We provide a relation which describes how the entanglement of two d-level systems evolves as either system undergoes an arbitrary physical process. The dynamics of the entanglement turns out to be of a simple form, and is fully captured by a single quantity.

M. B. Hastings, A. W. Harrow

We introduce the concept of quantum tensor product expanders. These are expanders that act on several copies of a given system, where the Kraus operators are tensor products of the Kraus operator on a single system. We begin with the classical case, and show that a classical two-copy expander can be used to produce a quantum expander. We then discuss the qua

Guangyong Xu, C. Broholm, Yeong-Ah Soh, G. Aeppli

Mesoscopic quantum phase coherence is important because it improves the prospects for handling quantum degrees of freedom in technology. Here we show that the development of such coherence can be monitored using magnetic neutron scattering from a one-dimensional spin chain Y2BaNiO5, a quantum spin fluid where no classical, static magnetic order is present. I

Sergey Agievich

We study generalized regular bent functions using a representation by bent rectangles, that is, special matrices with restrictions on rows and columns. We describe affine transformations of bent rectangles, propose new biaffine and bilinear constructions, study partitions of a vector space into affine planes of the same dimension and use such partitions to b

Ewa L. Lokas, Jaroslaw Klimentowski, Stelios Kazantzidis, Lucio Mayer

We model the recently published kinematic data set for Leo I dSph galaxy by fitting the solutions of the Jeans equations to the velocity dispersion and kurtosis profiles measured from the data. We demonstrate that when the sample is cleaned of interlopers the data are consistent with the assumption that mass follows light and isotropic stellar orbits with no

Sébastien Descotes-Genon, Alain Le Yaouanc

The vector form factor f_+(t) of the semileptonic decay D -> K l nu, measured recently with a high accuracy, can be used to determine the strong coupling constant g_{D_s^* D K}. The latter is related to the normalised coupling \hat{g} releveant in heavy-meson chiral perturbation theory. This determination relies on the estimation of the residue of the form f

Benjamin F. Jones

We discuss a method for calculating the Chern-Schwartz-MacPherson (CSM) class of a Schubert variety in the Grassmannian using small resolutions introduced by Zelevinsky. As a consequence, we show how to compute the Chern-Mather class and local Euler obstructions using small resolutions instead of the Nash blowup. The algorithm obtained for CSM classes also a

Neil Bevis, Paul M. Saffin

We explore the formation of cosmic string Y-junctions when strings of two different types collide, which has recently become important since string theory can yield cosmic strings of distinct types. Using a model containing two types of local U(1) string and stable composites, we simulate the collision of two straight strings and investigate whether the dyna

L. Bonora, M. Cvitan

We apply the &#34;trace anomaly method&#34; to the calculation of moments of the Hawking radiation of a Schwarzschild black hole. We show that they can be explained as the fluxes of chiral currents forming a W-infinity algebra. Then we construct the covariant version of these currents and verify that up to order 6 they are not affected by any trace anomaly.

Yoshihiro Mitsuka

We investigate the 1/8 BPS geometries with SU(2) x U(1) x SO(4) x R symmetry in IIB supergravity which were classified by Gava et al, (hep-th/0611065). It is desirable to have a complete set of differential equations imposed on the controlling functions such that they are not only necessary but also sufficient to produce supergravity solutions with those sym

Nikolay G. Moshchevitin

For a real $N\ge 1$ and a vector $ξ=(1,ξ_1,...,ξ_n)$ define a matrix $$ {\cal A} (ξ, N) = ({array}{ccccc} N^{-1} & 0& 0& ... &0 \cr N^{\frac{1}{n}} ξ_1 & -N^{\frac{1}{n}} & 0&... & 0 \cr N^{\frac{1}{n}} ξ_2 &0& -N^{\frac{1}{n}} & ... & 0 \cr ... &... &... &... \cr N^{\frac{1}{n}} ξ_n &0&0&... &- N^{\frac{1}{n}} {array}) $$ and a lattice $$ Λ(ξ, N) = {\cal A}

Tim Bratten

This is an expository article, written for a special edition of the journal of the UMA (Union Matematica Argentina) commemorating the mathematician Misha Cotlar. The article gives an introduction to the n-homology groups and surveys some developments, with a particular emphasis on results pertaining to the problem of calculating n-homology groups.

Ronny Luss, Alexandre d&#39;Aspremont

We propose a method for support vector machine classification using indefinite kernels. Instead of directly minimizing or stabilizing a nonconvex loss function, our algorithm simultaneously computes support vectors and a proxy kernel matrix used in forming the loss. This can be interpreted as a penalized kernel learning problem where indefinite kernel matric

Henryk Czyz, Johann H. Kuhn, Agnieszka Wapienik

An improved description of four-pion production in electron-positron annihilation and in tau lepton decays is presented. The model amplitude is fitted to recent data from BaBar which cover a wide energy range and which were obtained exploiting the radiative return. Predicting tau decay distributions from e+e- data and comparing these predictions with ALEPH a