October 2003 arXiv papers — page 11

Marcus T. Grisaru, Liuba Mazzanti, Silvia Penati, Laura Tamassia

In this paper we continue the program, initiated in Ref. hep-th/0112246, to investigate an integrable noncommutative version of the sine-Gordon model. We discuss the origin of the extra constraint which the field function has to satisfy in order to guarantee classical integrability. We show that the system of constraint plus dynamical equation of motion can

H. Ballhausen, J. Berges, C. Wetterich

We present a calculation of critical phenomena directly in continuous dimension d employing an exact renormalization group equation for the effective average action. For an Ising-type scalar field theory we calculate the critical exponents nu(d) and eta(d) both from a lowest--order and a complete first--order derivative expansion of the effective average act

Wung-Hong Huang

The thermal instability of the giant graviton is investigated within the BMN matrix model. We calculate the one-loop thermal correction of the quantum fluctuation around the trivial vacuum and giant graviton respectively. From the exact formula of the free energy we see that at low temperature the giant graviton is unstable and will dissolve into vacuum fluc

David R. Alves

The average of 14 recent measurements of the distance to the Large Magellanic Cloud (LMC) implies a true modulus of 18.50 +- 0.02 mag, and demonstrates a trend in the past 2 years of convergence toward a standard value. The distance indicators reviewed are the red clump, the tip of the red giant branch, Cepheid, RR Lyrae, and Mira variable stars, cluster mai

Pankaj Kumar Mishra, Ambarish Kunwar, Sutapa Mukherji, Debashish Chowdhury

Microtubules are stiff filamentary proteins that constitute an important component of the cytoskeleton of cells. These are known to exhibit a dynamic instability. A steadily growing microtubule can suddenly start depolymerizing very rapidly; this phenomenon is known as ``catastrophe''. However, often a shrinking microtubule is ``rescued'' and

Matt Visser, David L. Wiltshire

The "gravastar" picture developed by Mazur and Mottola is one of a very small number of serious challenges to our usual conception of a "black hole". In the gravastar picture there is effectively a phase transition at/ near where the event horizon would have been expected to form, and the interior of what would have been the black hole is rep

Valery S. Shchesnovich, Anatoly M. Kamchatnov, Roberto A. Kraenkel

We consider the ground state properties of mixed Bose-Einstein condensates of 87Rb and 85Rb atoms in the isotropic pancake trap, for both signs of the interspecies scattering length. In the case of repulsive interspecies interaction, there are the axially-symmetric and symmetry-breaking ground states. The threshold for the symmetry breaking transition, which

Camil Muscalu, Jill Pipher, Terence Tao, Christoph Thiele

In the first part of the paper we prove a bi-parameter version of a well known multilinear theorem of Coifman and Meyer. As a consequence, we generalize the Kato-Ponce inequality in nonlinear PDE, obtaining a fractional Leibnitz rule for derivatives in the $x_1$ and $x_2$ directions simultaneously. Then, we show that the double bilinear Hilbert transform doe

S. J. Curran, J. K. Webb, M. T. Murphy, Y. M. Pihlström

Strong constraints on possible variations in fundamental constants can be derived from HI 21-cm and molecular rotational absorption lines observed towards quasars. With the aim of forming a statistical sample of constraints we have begun a program of systematic searches for such absorption systems. Here we describe molecular rotational searches in 25 damped

S. Twareque Ali, R. Roknizadeh, M. K. Tavassoly

Starting with the canonical coherent states, we demonstrate that all the so-called nonlinear coherent states, used in the physical literature, as well as large classes of other generalized coherent states, can be obtained by changes of bases in the underlying Hilbert space. This observation leads to an interesting duality between pairs of generalized coheren

S. M. Fei, X. H. Gao, X. H. Wang, Z. X. Wang

We give a canonical form of PPT states in ${\cal C}^2 \otimes {\cal C}^2\otimes {\cal C}^2 \otimes {\cal C}^N$ with rank=$N$. From this canonical form a necessary separable condition for these states is presented.

P. Kosinski, P. Maslanka

We consider a particle of half-integer spin which is nonrelativistic in the rest frame. Assuming the particle is completely polarized along third axis we calculate the Bloch vector as seen by a moving observer. The result for its length is expressed in terms of dispersion of some vector operator linear in momentum. The relation with the localization properti

Levon Mardoyan

This paper deals with the dynamical system that generalizes the MIC-Kepler system. It is shown that the Schrödinger equation for this generalized MIC-Kepler system can be separated in prolate spheroidal coordinates. The coefficients of the interbasis expansions between three bases (spherical, parabolic and spheroidal) are studied in detail. It is found that

Li Yang, Ling-An Wu

We suggest here a two-point eavesdropping strategy to two nonorthogonal states protocol of quantum key distribution over a fiber-optic channel. Suppose that the single-photon sources and detectors of Alice, Bob and Eves are ideal ones, the two-point attack can break the two nonorthogonal states protocol if the distance between Alice and Bob is sufficiently l

P. G. Higgs, D. Jameson, H. Jow, M. Rattray

Animal mitochondrial genomes usually have two transfer RNAs for Leucine: one, with anticodon UAG, translates the four-codon family CUN, whilst the other, with anticodon UAA, translates the two-codon family UUR. These two genes must differ at the third anticodon position, but in some species the genes differ at many additional sites, indicating that these gen

L. E. Flores, E. J. Aguilar, V. C. Barbosa, L. A. V. de Carvalho

The immune system protects the body against health-threatening entities, known as antigens, through very complex interactions involving the antigens and the system's own entities. One remarkable feature resulting from such interactions is the immune system's ability to improve its capability to fight antigens commonly found in the individual's en

P. B. Warren, P. R. ten Wolde

We have performed a statistical analysis of the spatial distribution of operons in the transcriptional regulation network of Escherichia coli. The analysis reveals that operons that regulate each other and operons that are coregulated tend to lie next to each other on the genome. Moreover, these pairs of operons tend to be transcribed in diverging directions

Sergey V. Naydenov, Vladimir D. Ryzhikov, Craig F. Smith

A direct method is proposed for reconstruction of the effective atomic number by means of multi-energy radiography of the material. The accuracy of the method is up to 95% . Advantages over conventional radiographic methods, which ensure accuracy of just about 50%, are discussed. A physical model has been constructed, and general expressions have been obtain

B. H. Lavenda, J. Dunning-Davies

The Tsallis entropy is shown to be an additive entropy of degree-q that information scientists have been using for almost forty years. Neither is it a unique solution to the nonadditive functional equation from which random entropies are derived. Notions of additivity, extensivity and homogeneity are clarified. The relation between mean code lengths in codin

Michael C. Parker, Stuart D. Walker

In this paper we present an analysis of information transfer based on Landauer's principle (i.e. erasure of information is associated with an increase in entropy), as well as considerations of analyticity and causality. We demonstrate that holomorphic functions allowing complete analytic continuation cannot propagate any information, such that informatio

J. M. Montanero

An overview of recent work on Monte Carlo simulations of a granular binary mixture is presented. The results are obtained numerically solving the Enskog equation for inelastic hard-spheres by means of an extension of the well-known direct Monte Carlo simulation (DSMC) method. The homogeneous cooling state and the stationary state reached using the Gaussian t

R. Zhu, X. S. Peng, S. H Sun, Y. Lin

Ternary oxide forsterite Mg2SiO4 single-crystalline nanobelts have been synthesized at high yields via SiO2 assistant-oxide through a VS process. The PL properties of the forsterite Mg2SiO4 nanobelts were observed. The emission peak at 625 nm is attributed to the 4T1 - 6A1 transition of the trace Mn2+ ions. The other emission peak at 400nm may be due to the

J. O. Indekeu

In this Note a social network model for opinion formation is proposed in which a person connected to $q$ partners pays an {\em attention} $1/q$ to each partner. The mutual attention between two connected persons $i$ and $j$ is taken equal to the geometric mean $1/\sqrt{q_iq_j}$. Opinion is represented as usual by an Ising spin $s=\pm 1$ and mutual attention

S. V. Utyuzhnikov

To study and develop wall-functions for low-Reynolds-number models, a model linear equation is introduced. This equation simulates major mathematical peculiarities of the low-Reynolds-number model including a near wall sub-layer and transition region. Dirichlet and Newman boundary-value problems are considered. The standard and analytical wall-functions are

Li-Jen Chen, David J. Thouless, Jian-Ming Tang

Inequality width-amplitude relations for three-dimensional Bernstein-Greene-Kruskal solitary waves are derived for magnetized plasmas. Criteria for neglecting effects of nonzero cyclotron radius are obtained. We emphasize that the form of the solitary potential is not tightly constrained, and the amplitude and widths of the potential are constrained by inequ

B. Kerbikov, A. Stavinsky, V. Fedotov

We present a simple explanation for the recently observed near-threshold proton-antiproton enhancement. It is described by a set of low-energy parameters deduced from the analysis of NantiN experiments at LEAR. We predict a related effect in photoproduction reaction under study by CLAS collaboration.

Antonio M. Lallena, Marta Anguiano, Giampaolo Co'

A model to study two-proton emission from nuclei induced by electromagnetic probes is developed. The process is due to one-body electromagnetic operators, acting together with short-range correlations, and two-body $Δ$ currents. The model includes all the diagrams containing a single correlation function. The sensitivity of the cross section to the details o

T. Van Cauteren, D. Merten, T. Corthals, S. Janssen

Predictions for the electromagnetic form factors of the Lambda$, Sigma and Xi hyperons are presented. The numerical calculations are performed within the framework of the fully relativistic constituent-quark model developed by the Bonn group. The computed magnetic moments compare favorably with the experimentally known values. Most magnetic form factors G_M(

Viktor A. Podolskiy, Evgenii E. Narimanov

Classical counterparts of a great variety of quantum systems, from atomic physics to quantum wells and quantum dots, to optical, microwave, and acoustic resonators exhibit partially chaotic dynamics. Since it is often impossible to measure the temporal dynamics in qunatum systems, the main and probably the most dramatic manifestation of classical chaos in th

Luis G. Morelli, Guillermo Abramson, Marcelo N. Kuperman

We study a model of associative memory based on a neural network with small-world structure. The efficacy of the network to retrieve one of the stored patterns exhibits a phase transition at a finite value of the disorder. The more ordered networks are unable to recover the patterns, and are always attracted to mixture states. Besides, for a range of the num

V. V. Varlamov

The massless field of spin 1 is defined on the eight-dimensional configuration space; this space is a direct product of Minkowski space and of a two-dimensional complex sphere. Field equations for the spin-one field are derived from a Dirac-like Lagrangian separately for the translation group and Lorentz group parts. It is shown that a Dirac form of Maxwell

L. I. Petrova

At present the theory of skew-symmetric exterior differential forms has been developed. The closed exterior forms possess the invariant properties that are of great importance. The operators of the exterior form theory lie at the basis of the differential and integral operators of the field theory. However, the theory of exterior forms, being invariant one,

Peter A. Becker

Several new formulas are developed that enable the evaluation of a family of definite integrals containing the product of two Whittaker W-functions. The integration is performed with respect to the second index, and the first index is permitted to have any complex value, within certain restrictions required for convergence. The method utilizes complex contou

Abhay Parvate, A. D. Gangal

A new calculus based on fractal subsets of the real line is formulated. In this calculus, an integral of order $α, 0 < α\leq 1$, called $F^α$-integral, is defined, which is suitable to integrate functions with fractal support $F$ of dimension $α$. Further, a derivative of order $α, 0 < α\leq 1$, called $F^α$-derivative, is defined, which enables us to differ

G. Sardanashvily

Jets of modules over a commutative ring are well known to make up the representative objects of linear differential operators on these modules. In noncommutative geometry, jets of modules provide the representative objects only of a certain class of first order differential operators. As a consequence, a generalization of the standard Lagrangian formalism on

G. Sardanashvily

Several definitions of differential operators on modules over noncommutative rings are discussed.

Simon Gravel

We present in this article all Hamiltonian systems in E(2) that are separable in cartesian coordinates and that admit a third-order integral, both in quantum and in classical mechanics. Many of these superintegrable systems are new, and it is seen that there exists a relation between quantum superintegrable potentials, invariant solutions of the Korteweg-De

Nathan Ng

Discrete moments of the Riemann zeta function were studied by Gonek and Hejhal in the 1980&#39;s. They independently formulated a conjecture concerning the size of these moments. In 1999, Hughes, Keating, and O&#39;Connell, by employing a random matrix model, made this conjecture more precise. Subject to the Riemann hypothesis, we establish upper and lower b

Nathan Ng

Let the summatory function of the Möbius function be denoted $M(x)$. We deduce in this article conditional results concerning $M(x)$ assuming the Riemann Hypothesis and a conjecture of Gonek and Hejhal on the negative moments of the Riemann zeta function. The main results shown are that the weak Mertens conjecture and the existence of a limiting distribution

Alexander Burstein, Sergey Kitaev, Toufik Mansour

We enumerate the independent sets of several classes of regular and almost regular graphs and compute the corresponding generating functions. We also note the relations between these graphs and other combinatorial objects and, in some cases, construct the corresponding bijections.

Vincent Bonini, Pengzi Miao, Jie Qing

A rigidity result for weakly asymptotically hyperbolic manifolds with lower bounds on Ricci curvature is proved without assuming that the manifolds are spin. The argument makes use of a quasi-local mass characterization of Euclidean balls from \cite{Miao} \cite{S_T} and eigenfunction compactification ideas from \cite{Qing}.

Peter Mani-Levitska, Sinisa Vrecica, Rade Zivaljevic

One of our result is that 5 measurable sets in $R^8$ always admit an equipartition by 2 hyperplanes. This is an instance of a general equipartition problem (formulated by B. Gr{\&#34; u}nbaum and H. Hadwiger) which can be reduced to the question of (non)existence of a $W_k$-equivariant map where $W_k$ is the group of symmetries of a $k$-cube. We show that th

A. Alzati, A. Tortora

We define the monomial invariants of a projective variety $Z$; they are invariants coming from the generic initial ideal of $Z$. Using this notion, we generalize a result of Cook: If $Z$ is an integral variety of codimension two, satisfying the additional hypothesis $s_Z=s_Γ,$ then its monomial invariants are connected.

Michel Cahen, Simone Gutt, Lorenz Schwachhoefer

Given the Euclidean space $\R^{2n+2}$ endowed with a constant symplectic structure and the standard flat connection, and given a polynomial of degree 2 on that space, Baguis and Cahen have defined a reduction procedure which yields a symplectic manifold endowed with a Ricci-type connection. We observe that any symplectic manifold of dimension greater than 2

Mariapia Palombaro, Marcello Ponsiglione

We prove that for any connected open set $Ω\subset \R^n$ and for any set of matrices $K=\{A_1,A_2,A_3\}\subset M^{m\times n}$, with $m\ge n$ and rank$(A_i-A_j)=n$ for $i\neq j$, there is no non-constant solution $B\in L^{\infty}(Ω,M^{m\times n})$, called exact solution, to the problem Div B=0 \quad \text{in} D&#39;(Ω,\R^m) \quad \text{and} \quad B(x)\in K \t

Sergei Evdokimov, Ilia Ponomarenko

The famous Burnside-Schur theorem states that every primitive finite permutation group containing a regular cyclic subgroup is either 2-transitive or isomorphic to a subgroup of a 1-dimensional affine group of prime degree. It is known that this theorem can be expressed as a statement on Schur rings over a finite cyclic group. Generalizing the latters we int

Nordine Mir

Let $M$ be a connected real-analytic hypersurface in $\C^N$ and $§$ the unit real sphere in $\C^{N&#39;}$, $N&#39;> N\geq 2$. Assume that $M$ does not contain any complex-analytic hypersurface of $\C^N$ and that there exists at least one strongly pseudoconvex point on $M$. We show that any CR map $f\colon M\to §$ of class $C^{N&#39;-N+1}$ extends holomorphic

Yuriy A. Drozd

This survey presents some recent results of G.-M.Greuel and the author on vector bundles over algebraic curves and on Cohen-Macaulay modules over surface singularities. It is mainly devoted to the classification problems, especially to the tame-wild dichotomy and to the description of vector bundles and Cohen-Macaulay modules in the tame cases.

Stefan Forcey

The 2-category V-Cat of categories enriched over a braided monoidal category V is not itself braided in any way that is based upon the braiding of V. The exception is the case in which V is symmetric, which leads to V-Cat being symmetric as well. This paper describes how these facts are related to a categorical analogue of topological delooping. It seems tha

Wei-Ping Li, Zhenbo Qin, Weiqiang Wang

We study the ideals of the rational cohomology ring of the Hilbert scheme X^{[n]} of n points on a smooth projective surface X. As an application, for a large class of smooth quasi-projective surfaces X, we show that every cup product structure constant of H^*(X^{[n]}) is independent of n; moreover, we obtain two sets of ring generators for the cohomology ri

Gautam Bharali

Let Ωbe a bounded, weakly convex domain in C^n, n>1, having real-analytic boundary. A(Ω) is the algebra of all functions holomorphic in Ωand continuous upto the boundary. A submanifold M\subset \partialΩis said to be complex-tangential if T_p(M) lies in the maximal complex subspace of T_p(\partialΩ) for each p \in M. We show that for real-analytic submanifol

Guenther Hoermann

We introduce an intrinsic notion of Hoelder-Zygmund regularity for Colombeau generalized functions. In case of embedded distributions belonging to some Zygmund-Hoelder space this is shown to be consistent. The definition is motivated by the well-known use of Littlewood-Paley decomposition in characterizing Hoelder-Zygmund regularity for distributions. It is

Michael J. May, Raman Sundrum

We write an explicit local action for a large extra dimensions stabilization scenario due to Arkani-Hamed, Hall, Smith and Weiner (AHSW). Our action allows the AHSW proposal to be generalized to non-Poincare invariant configurations, supersymmetric extensions, quantum effective field theory, and cosmological scenarios. The central step in constructing the ac

L. P. Colatto, A. L. A. Penna, W. C. Santos

We consider a model with a charged vector field along with a Cremmer-Scherk-Kalb-Ramond (CSKR) matter field coupled to a U(1) gauge potential. We obtain a natural Lorentz symmetry violation due to the local U(1) spontaneous symmetry breaking mechanism triggered by the imaginary part of the vector matter. The choice of the unitary gauge leads to the decouplin

V. T. Kim, G. B. Pivovarov, J. P. Vary

We reproduce Chang&#39;s duality condition in a regularized $ϕ^4_{1+1}$ theory quantized on a light front. The regularization involves higher derivatives in the Lagrangian, renders the model finite in the ultraviolet, and does not require introduction of a finite size of the system. It is demonstrated that the light-front quantization is a natural way to tre

Feng Yuan

We study the beam single spin asymmetry in semi-inclusive hadron production in deep inelastic scattering in at order 1/Q. There are two competing contributions: the leading order transverse momentum dependent parton distribution $h_1^\perp(x,k_\perp)$ convoluted with chiral-odd fragmentation function $\hat e(z)$, and the chiral-odd distribution function $e(x

S. J. Brodsky, C. E. Carlson, J. R. Hiller, D. S. Hwang

We show that measurements of the proton&#39;s polarization in electron-positron annihilation to a proton-antiproton pair $e^+ e^- \to p \bar p$ strongly discriminate between the analytic forms of models which fit the proton form factors in the spacelike region. In particular, the single-spin asymmetry normal to the scattering plane measures the relative phas

Andrzej Czarnecki, William J. Marciano, Arkady Vainshtein

Hadronic electroweak corrections to the muon anomalous magnetic moment (g-2) are reviewed. Emphasis is on clarification of discrepancies among various published studies. A theorem on non-renormalization of the transversal part of a correlator of two vector currents and an axial current is reviewed and its consequences in the form of superconvergent sum rules

A. Accardi, F. Arleo, N. Armesto, R. Baier

We discuss the importance of high-pT hadron and jet measurements in nucleus-nucleus collisions at the CERN Large Hadron Collider.

Tim Oliver Eynck, Eric Laenen, Lorenzo Magnea

The techniques leading to the resummation of threshold logarithms in the Drell-Yan cross section and other processes can be used to show that also terms independent on the Mellin variable N exponentiate. Comparison with explicit two-loop calculations shows that within this class of terms the exponentiation of the one-loop result together with the running of

V. Kopeikin, L. Mikaelyan, V. Sinev

Searches for mass-3 component in the electron neutrino flavor state $\sinθ_{13}$ and for sterile neutrinos can be carried out in the same small mixing angle antineutrino oscillation experiment at a reactor. As an example we consider a layout, which involves several movable antineutrino spectrometers, stationed at distances 1700 m $-$ 50 m from a reactor. The

Chris Dawson

We report on an exploratory study of N_f=2 dynamical domain wall fermions and the DBW2 gauge action at weak coupling. Details of improved simulation algorithms and preliminary results for the hadron spectrum and renormalised light and strange quark masses will be presented.

Bugra Borasoy, Randy Lewis, Pierre-Philippe A. Ouimet

Chiral perturbation theory can be defined and regularized on a spacetime lattice. A few motivations are discussed here, and an explicit lattice Lagrangian is reviewed. A particular aspect of the connection between lattice chiral perturbation theory and lattice QCD is explored through a study of the Wess-Zumino-Witten term.

Frederic D. R. Bonnet, Robert G. Edwards, George T. Fleming, Randy Lewis

A ratio of lattice correlation functions is identified from which the pion form factor can be obtained directly. Preliminary results from quenched Wilson simulations are presented.

L. Schmitt, S. Paul, R. Kuhn, M. A. Moinester

The search for doubly charmed baryons has been a topic for COMPASS from the beginning. Requiring however a complete spectrometer and highest possible trigger rates this measurement has been postponed. The scenario for such a measurement in the second phase of COMPASS is outlined here. First studies of triggering and simulation of the setup have been performe

The OPAL collaboration, G. Abbiendi

We present the first experimental results based on the jet boost algorithm, a technique to select unbiased samples of gluon jets in e+e- annihilations, i.e. gluon jets free of biases introduced by event selection or jet finding criteria. Our results are derived from hadronic Z0 decays observed with the OPAL detector at the LEP e+e- collider at CERN. First, w

Gy. Szondy

&#34;There are several interpretations and approaches to relativity. All of them are characterized by the fact that none of them is accepted by physicists without doubts, even the Einsteinian General Relativity! Only those theories can get into the spotlight that predicts something that is different from predictions of other concurrent theories. From this po

Ali E. Abbas

Recent literature in the last Maximum Entropy workshop introduced an analogy between cumulative probability distributions and normalized utility functions. Based on this analogy, a utility density function can de defined as the derivative of a normalized utility function. A utility density function is non-negative and integrates to unity. These two propertie

Ali E. Abbas

Richard Cox [1] set the axiomatic foundations of probable inference and the algebra of propositions. He showed that consistency within these axioms requires certain rules for updating belief. In this paper we use the analogy between probability and utility introduced in [2] to propose an axiomatic foundation for utility inference and the algebra of preferenc

J. Higbie, D. M. Stamper-Kurn

Resonant Raman coupling between internal levels induced by continuous illumination of non-collinear laser beams can create double-well momentum-space potentials for multi-level ``periodically-dressed&#39;&#39; atoms. We develop an approximate many-body formalism for a weakly interacting, trapped periodically-dressed Bose gas which illustrates how a tunable e

C. Reichhardt, C. J. Olson Reichhardt

Using numerical simulations we show that novel transport phenomena can occur for vortices moving in periodic pinning arrays when two external perpendicular ac drives are applied. In particular, we find a ratchet effect where the vortices can have a net dc drift even in the absence of a dc drive. This ratchet effect can occur for ac drives which create orbits

T. A. Nguyen, S. Mackowski, H. Rho, H. E. Jackson

We show that two major carrier excitation mechanisms are present in II-VI self-assembled quantum dots. The first one is related to direct excited state - ground state transition. It manifests itself by the presence of sharp and intense lines in the excitation spectrum measured from single quantum dots. Apart from these lines, we also observe up to four much

J. I. Perea, D. Porras, C. Tejedor

We study the dynamics of a quantum dot embedded in a three-dimensional microcavity in the strong coupling regime in which the quantum dot exciton has an energy close to the frequency of a confined cavity mode. Under the continuous pumping of the system, confined electron and hole can recombine either by spontaneous emission through a leaky mode or by stimula

A. Kenoufi, J. Polonyi

An improvement of the Energy Renormalization Group method is proposed for systems with small gap, based on the projection methods developed by H. Feshbach. It is tested for the ground state energy of the one-dimensional tight-binding model.

L. Civale, B. Maiorov, A. Serquis, J. O. Willis

We present a comparative study of the angular dependent critical current density in YBa2Cu3O7 films deposited on IBAD MgO and on single crystal MgO and SrTiO3 substrates. We identify three angular regimes where pinning is dominated by different types of correlated and uncorrelated defects. We show that those regimes are present in all cases, indicating that

L. O. Baksmaty, S. J. Woo, S. Choi, N. P. Bigelow

We describe the excitations of a vortex lattice in rapidly rotating trapped Bose-Einstein Condensates, focusing on their evolution from the hydrodynamic to the quantum Hall regimes. We observe the dramatic changes and show that single particle states are an increasingly dominant signature of the spectrum. We interpret the behavior by analogy with the integra

Sara Casalbuoni, Lars von Sawilski, Jürgen Kötzler

From the magnetic response of Nb-cylinders to time-varying fields the AC-conductivity, $σ&#39;-iσ&#39;&#39;$, and the critical current density $J_c^s$ are determined above the upper critical field $H_{c2}$. The field dependencies of $σ&#39;$ and $σ&#39;&#39;$ allow us to identify the nucleation of incoherent surface superconductivity (SSC) at $H_{c3}$ and of

A. P. F. Atman, P. Claudin

We investigate the stress response function of a layer of grains, i.e. the stress profile in response to a localized overload. The shape of the profile is very sensitive to the packing arrangement, and is thus a good signature of the preparation procedure of the layer. This study has been done by the use of molecular dynamics numerical simulations. Here, for

T. Champel, V. P. Mineev

We have investigated in frame of the quantum transport theory the magnetic quantum oscillations of the longitudinal magnetoresistance $ρ_{zz}$ in quasi two-dimensional metals for a magnetic field perpendicular to the layers. Giant Shubnikov-de Haas oscillations are found when the cyclotron energy $\hbar ω_{c}$ is much larger than the interlayer transfer inte

M. Bednarz, J. Knoester, V. A. Malyshev

We calculate the temperature dependence of the fluorescence Stokes shift and the fluorescence decay time in linear Frenkel exciton systems resulting from the thermal redistribution of exciton population over the band states. The following factors, relevant to common experimental conditions, are accounted for in our kinetic model: (weak) localization of the e

M. Bednarz, V. A. Malyshev, J. Knoester

We model the optical dynamics in linear Frenkel exciton systems governed by scattering on static disorder and lattice vibrations, and calculate the temperature dependent fluorescence spectrum and lifetime. The fluorescence Stokes shift shows a nonmonotonic behavior with temperature, which derives from the interplay of the local band-edge level structure and

E. O. Kamenetskii, O. Voskoboynikov

We consider an implementation of quantum gates for quantum computation using magnetostatic/magnetoelectric (MS/ME) macroscopically quantized states in small ferrite disks. Confinement phenomena for MS oscillations in a normally magnetized ferrite disk show typical atomic properties like discrete energy levels. Because of discrete energy eigenstates of MS osc

A. Levy Yeyati, A. Martin-Rodero, E. Vecino

The transport properties of a quantum dot coupled to superconducting leads are analyzed. It is shown that the quasiparticle current in the Kondo regime is determined by the non-equilibrium dynamics of subgap states (Andreev states) under an applied voltage. The current at low bias is suppressed exponentially for decreasing Kondo temperature in agreement with

Ulrich H. E. Hansmann

A generalized-ensemble technique, multicanonical sampling, is used to study the folding of a 34-residue human parathyroid hormone fragment. An all-atom model of the peptide is employed and the protein-solvent interactions are approximated by an implicit solvent. Our results demonstrate that generalized-ensemble simulations are well suited to sample low-energ

Yuichi Nemoto, Takashi Yamaguchi, Takenobu Horino, Mitsuhiro Akatsu

Lattice effects in a cerium based clathrate compound Ce_3Pd_20Ge_6 with a cubic Cr_23C_6-type structure have been investigated by ultrasonic and thermal expansion measurements. Elastic softenings of (C_11-C_12)/2 and C_44 proportional to the reciprocal temperature 1/T above T_Q1 = 1.25 K are well described in terms of the quadrupole susceptibility for the gr

A. Gerber, A. Milner, A. Finkler, M. Karpovski

We study the contribution of different types of scattering sources to the extraordinary Hall effect. Scattering by magnetic nano-particles embedded in normal-metal matrix, insulating impurities in magnetic matrix, surface scattering and temperature dependent scattering are experimentally tested. Our new data, as well as previously published results on a vari

A. M. Kamchatnov

In the hydrodynamic approximation we obtain analytic solutions to the Gross-Pitaevskii equation with positive scattering length which describe expansions of the Bose-Einstein condensates in quasi-one and quasi-two dimensional geometries. The expansion laws are expressed in terms of the initial sizes of the condensate and the trap frequencies before release,

D. B. Saakian

The results by E. Gardner and B.Derrida have been enlarged for the complex temperatures and complex numbers of replicas. The phase structure is found. There is a connection with string models and their phase structure is analyzed from the REM&#39;s point of view.

U. Buchenau, S. Kahle

This is a comment on the beautiful results of Jeppe Dyre and Niels Boie Olsen, published as a recent Physical Review Letter.

Takahiro Harada

An expression for the energetic efficiency of a molecular motor is presented in terms of an effective temperature, which was defined based on the ratio of the correlation function to the susceptibility of its velocity. We also present a numerical result regarding this temperature for a thermal ratchet model. Furthermore, our expression of efficiency using kn

Peter Mayer, Ludovic Berthier, Juan P. Garrahan, Peter Sollich

We have recently shown that in non-equilibrium spin systems at criticality the limit $\Xin$ of the fluctuation-dissipation ratio X(t,tw) for t >> tw >> 1 can be measured using observables such as magnetization or energy [Phys. Rev.\ E {\bf 68}, 016116 (2003)]. Pleimling argues in a Comment [cond-mat/0309652] on our paper that for such observables correlation

T. Di Matteo, T. Aste, S. T. Hyde

We investigate the wealth evolution in a system of agents that exchange wealth through a disordered network in presence of an additive stochastic Gaussian noise. We show that the resulting wealth distribution is shaped by the degree distribution of the underlying network and in particular we verify that scale free networks generate distributions with power-l

C. W. Gardiner

A comprehensive input-output theory is developed for Fermionic input fields. Quantum stochastic differential equations are developed in both the Ito and Stratonovich forms. The major technical issue is the development of a formalism which takes account of anticommutation relations between the Fermionic driving field and those system operators which can chang

F. Alonso-Marroquin, H. J. Herrmann

We investigate the quasi-static mechanical response of soils under cyclic loading using a discrete model of randomly generated convex polygons. This response exhibits a sequence of regimes, each one characterized by a linear accumulation of plastic deformation with the number of cycles. At the grain level, a quasi-periodic ratchet-like behavior is observed a

Robert Desbrandes

This paper was withdrawn by the author due to an error in the treatment of the earth acceleration in the accelerated frame of the Cooper pairs.

Martin Depken

Considering Langevin dynamics we derive the general form of the stochastic differential that satisfies the Gallavotti-Cohen symmetry. This extends the work previously done by Kurchan, and Lebowitz and Spohn on such systems, and we treat systems with and without inertia in a unified manner. We further shown that for systems with a time-reversal invariant stea

Anil K. Pradhan

Ongoing activities under an international collaboration of atomic physicists and astrophysicists under the Iron Project and the RmaX Project, with applications to X-ray astronomy, are briefly described.

Avi M. Mandell, Jian Ge, Norm Murray

Using high-resolution, high quality spectra we investigate the presence of $^6$Li in two lithium-poor stars that host extrasolar planetary systems. We present improved atomic and molecular line lists for the region in the vicinity of the lithium line at 6707.8 Å, and we produce an excellent fit to the solar spectrum. From line profile fitting, we find result

J. S. Lazendic, P. O. Slane, B. M. Gaensler, S. P. Reynolds

G347.3-0.5 is one of three shell-type supernova remnants in the Galaxy whose X-ray spectrum is dominated by nonthermal emission. This puts G347.3-0.5 in the small, but growing class of SNRs for which the X-ray emission reveals directly the presence of extremely energetic electrons accelerated by the SNR shock. We have obtained new high-resolution X-ray and r

M. Livio, J. E. Pringle

Recent observations show a clear correlation between the probability of hosting a planet and the metallicity of the parent star. Since radial velocity surveys are biased, however, towards detecting planets with short orbital periods, the probability-metallicity correlation could merely reflect a dependence of migration rates on metallicity. We investigated t