September 2006 arXiv papers — page 28

F. Franchini, A. R. Its, B. -Q. Jin, V. E. Korepin

Entanglement in the ground state of the XY model on the infinite chain can be measured by the von Neumann entropy of a block of neighboring spins. We study a double scaling limit: the size of the block is much larger then 1 but much smaller then the length of the whole chain. The entropy of the block has an asymptotic limit. We study this limiting entropy as

K. Farakos, P. Pasipoularides

We present our recent work on brane world models with a non-minimally coupled scalar field. In [9] we examined the stability of these models against scalar field perturbations and we discussed possible physical implications, while in [10] we developed a numerical approach for the solution of the Einstein equations with the non-minimally coupled scalar field.

BES Collaboration, M. AblikimJ

Using 14M $\psi (2S)$ events collected at BESII, the branching fraction of $\psi (2S)\to \tau ^{+}\tau ^{-}$ is measured to be $Br_{\tau \tau}=(3.10\pm 0.21\pm 0.38)\times 10^{-3}$, where the first error is statistical and the second is systematic.

Shotaro Akaho

Canonical correlation analysis is a technique to extract common features from a pair of multivariate data. In complex situations, however, it does not extract useful features because of its linearity. On the other hand, kernel method used in support vector machine is an efficient approach to improve such a linear method. In this paper, we investigate the eff

L. Kunyansky

We derive explicit formulas for the reconstruction of a function from its integrals over a family of spheres, or for the inversion of the spherical mean Radon transform. Such formulas are important for problems of thermo- and photo- acoustic tomography. A closed-form inversion formula of a filtration-backprojection type is found for the case when the centers

Leonid Malyshkin, Russell M. Kulsrud

In this paper two theoretical approaches for the calculation of the rate of quasi-stationary, two-dimensional magnetic reconnection with nonuniform anomalous resistivity are considered in the framework of incompressible magnetohydrodynamics (MHD). In the first, ``global'' equations approach the MHD equations are approximately solved for a whole recon

Youngkyun Jung

The nanoscale cylindrical Couette flow is investigated by means of molecular dynamics simulations, in the case where the inner cylinder is rotating whereas the outer cylinder is at rest. We find that the tangential velocity of the low is inverted when the fluid-wall interaction near the outer cylinder is weak and the fluid density is low. The unusual velocit

Marco Caminati, Francesco De Martini, Riccardo Perris, Fabio Sciarrino

We investigate the multiparticle quantum superposition and the persistence of multipartite entanglement of the quantum superposition generated by the quantum injected high-gain optical parametric amplification of a single photon. The physical configuration based on the optimal universal quantum cloning has been adopted to investigate how the entanglement and

Ramon Lapiedra

Some new Bell inequalities for consecutive measurements are deduced under joint realism assumption, using some perfect correlation property. No locality condition is needed. When the measured system is a macroscopic system, joint realism assumption substitutes the non-invasive hypothesis advantageously, provided that the system satisfies the perfect correlat

Arne Traulsen, Jorge M. Pacheco, Lorens A. Imhof

In stochastic dynamical systems, different concepts of stability can be obtained in different limits. A particularly interesting example is evolutionary game theory, which is traditionally based on infinite populations, where strict Nash equilibria correspond to stable fixed points that are always evolutionarily stable. However, in finite populations stochas

Arne Traulsen, Martin A. Nowak, Jorge M. Pacheco

We study evolutionary game dynamics in finite populations. We analyze an evolutionary process, which we call pairwise comparison, for which we adopt the ubiquitous Fermi distribution function from statistical mechanics. The inverse temperature in this process controls the intensity of selection, leading to a unified framework for evolutionary dynamics at all

Keiichi Homma, Satoshi Fukuchi, Yoji Nakamura, Takashi Gojobori

The formation mechanism of operons remains controversial despite the proposal of many models. Although acquisition of genes from other species, horizontal gene transfer, is considered to occur, definitive concrete cases have been unavailable. It is desirable to select horizontally transferred genes reliably and examine their relationship to operons. We here

C. C. Barros

The electronic structure of heavy elements, when described in a space-time which the metric is affected by the electromagnetic interaction, presents instabilities. These instabilities increase with the atomic number, and above a critical value, become important. The consistency of this theory [1], [2] and a formulation based on the energy-momentum tensor is

Teodor Burghelea, Enrico Segre, Victor Steinberg

We discuss the role of elastic stress in the statistical properties of elastic turbulence, realized by the flow of a polymer solution between two disks. The dynamics of the elastic stress are analogous to those of a small scale fast dynamo in magnetohydrodynamics, and to those of the turbulent advection of a passive scalar in the Batchelor regime. Both syste

Kévin Beck, Olivier Rozenbaum, M. Al-Mukhtar, Alain Plançon

Among the parameters influencing stone deterioration, moisture and water movements through the pore network are essential. This communication presents differents methods to characterize stones and to determinate the water transfer properties. Results are analysed for two limestones having similar total porosity, but characterized by different pore networks.

Savely G. Karshenboim

Sum rules for the energy levels of a hyperfine multiplet in a constant uniform magnetic field is presented. It is found that for any values of the electron angular moment and the nuclear spin there are certain linear combinations of energy levels which do not depend on the magnetic field and can be used to determine the unperturbated hfs separation in the pr

M. Guessmann, G. Wunner, A. Pelster

We follow our general model in Ref. [3] and analyze the formation of retinotopic projections for the biologically relevant situation of spherical geometries. To this end we elaborate both a linear and a nonlinear synergetic analysis which results in order parameter equations for the dynamics of connection weights between two spherical cell sheets. We show th

M. Al-Mukhtar, Kévin Beck

The focus of the study presented in this paper is to provide reliable criteria that can be used to estimate the degree of compatibility between the French limestone tuffeau and mortar. It is suggested through this study to use the same parent material (i.e., tuffeau) as mortar. The mortar used in this study is composed of non-hydraulic (hydrated) lime or hyd

R. Zwaska, M. Bishai, S. Childress, G. Drake

The Neutrinos at the Main Injector (NuMI) facility is a conventional horn-focused neutrino beam which produces muon neutrinos from a beam of mesons directed into a long evacuated decay volume. The relative alignment of the primary proton beam, target, and focusing horns affects the neutrino energy spectrum delivered to experiments. This paper describes a che

Alberto Accardi

I review a recently proposed scaling analysis of hadron suppression in Deeply Inelastic Scattering on nuclear targets measured at the HERMES experiment. The analysis can distinguish 2 competing explanations for the observed suppression, namely, quark radiative energy loss with long hadron formation times, and prehadron nuclear absorption with hadronization s

Y. Aritomo

We present the first attempt of the systematical investigation about the effects of shell correction energy for dynamical processes, which include fusion, fusion-fission and quasi-fission processes. In the superheavy mass region, for the fusion process, the shell correction energy plays a very important role and enhances the fusion probability, when the coll

M. Alvioli, C. Ciofi degli Atti, V. Palli

The effects of the final state interaction on the production of slow protons in semi-inclusive deep-inelastic lepton scattering off nuclei is considered within the spectator mechanism and a realistic approach in which the rescattering in the medium of both the recoiling proton and the hadronizing nucleon debris are taken into account.

C. Ciofi degli Atti, L. P. Kaptari, H. Morita

The mechanism of propagation of hadronic states in the medium is a key point for understanding particle-nucleus and nucleus-nucleus scattering at high energies. We have investigated the propagation of a baryon in the exclusive process A(e,e'p)B in few-nucleon systems using realistic nuclear wave functions and Glauber multiple scattering theory both in it

Chang Xu, Zhongzhou Ren

We make a systematic calculation on $α$-decay branching ratios to members of ground-state rotational band and to excited $0^{+}$ states of even-even nuclei by a simple barrier penetration approach. The branching ratios to the excited states of daughter nucleus are determined by the $α$-decay energy, the angular momentum of $α$-particle, and the excitation pr

Chang Xu, Zhongzhou Ren

The half-lives of newly observed $α$-emitters $^{105}$Te and $^{109}$Xe [Seweryniak \textit{et al.}, Phys. Rev. C \textbf{73}, 061301(R) (2006); Liddick \textit{et al.}, Phys. Rev. Lett. \textbf{97}, 082501 (2006)] are investigated by the density-dependent cluster model. The half-lives of $α$-emitters close to the N=Z line are also studied in a unified frame

David Winter

The origin of the azimuthal anisotropy in particle yields at high pT (pT > 5 GeV/c) in RHIC collisions remains an intriguing puzzle. Traditional flow and parton energy loss models have failed to completely explain the large v2 observed at high pT. Measurement of this parameter at high pT will help to gain an understanding of the interplay between flow, recom

David Winter

It has been established that "hard probes", observables involving high-momentum transfer, provide useful tools for studying the hot, dense medium created in nucleus-nucleus collisions at RHIC. The nuclear modification factor, azimuthal correlations, direct photon production, as well as the dependence of the nuclear modificaton factor on centrality an

Alex Kasman, Stephane Lafortune

The `ultra-discrete limit' has provided a link between integrable difference equations and cellular automata displaying soliton like solutions. In particular, this procedure generally turns strictly positive solutions of algebraic difference equations with positive coefficients into corresponding solutions to equations involving the "Max" operato

J. Asch, P. Stovicek

We study the dynamics of a classical particle moving in a punctured plane under the influence of a strong homogeneous magnetic field, an electrical background, and driven by a time-dependent singular flux tube through the hole. We exhibit a striking classical (de)localization effect: in the far past the trajectories are spirals around a bound center; the par

Hyeonbae Kang, Graeme W. Milton

Eshelby showed that if an inclusion is of elliptic or ellipsoidal shape then for any uniform elastic loading the field inside the inclusion is uniform. He then conjectured that the converse is true, i.e., that if the field inside an inclusion is uniform for all uniform loadings, then the inclusion is of elliptic or ellipsoidal shape. We call this the weak Es

L. D. Robinson, C. G. Lyons

In the September 1994 issue of Math Horizons the following problem is given in the Problem Section (p. 33, Problem 5): Lowest Terms - what fraction has the smallest denominator in the interval (19/94, 17/76)? In this paper we develop a general algorithm for solving problems of this type.

Alberto Corso, Uwe Nagel

Each partition $λ= (λ_1, λ_2, ..., λ_n)$ determines a so-called Ferrers tableau or, equivalently, a Ferrers bipartite graph. Its edge ideal, dubbed Ferrers ideal, is a squarefree monomial ideal that is generated by quadrics. We show that such an ideal has a 2-linear minimal free resolution, i.e. it defines a small subscheme. In fact, we prove that this prope

Alex Iosevich, Doowon Koh

We prove several incidence theorems in vector spaces over finite fields using bounds for various classes of exponential sums and apply these to Erdos-Falconer type distance problems.

F. Rodriguez Hertz, MA. Rodriguez Hertz, R. Ures

We prove, for f a partially hyperbolic diffeomorphism with center dimension one, two results about the integrability of its central bundle. On one side, we show that if the non wandering set of f is the whole manifold, and the manifold is 3 dimensional, then the absence of periodic points implies the unique integrability of the central bundle. On the opposit

Brian D. Boe, Jonathan R. Kujawa, Daniel K. Nakano

We study cohomology for classical Lie superalgebras $\mathfrak{g}$ (e.g. gl(m|n)) over the complex numbers. Using results from invariant theory, we show that there exist subsuperalgebras which detect the cohomology of $\mathfrak{g}.$ Furthermore, drawing inspiration from finite groups and restricted Lie algebras, we introduce the notion of support varieties

Alexey Cheskidov

An abstract framework for studying the asymptotic behavior of a dissipative evolutionary system $\mathcal{E}$ with respect to weak and strong topologies was introduced in [8] primarily to study the long-time behavior of the 3D Navier-Stokes equations (NSE) for which the existence of a semigroup of solution operators is not known. Each evolutionary system pos

Françoise Lust-Piquard, Quanhua Xu

We prove the little Grothendieck theorem for any 2-convex noncommutative symmetric space. Let $\M$ be a von Neumann algebra equipped with a normal faithful semifinite trace $\t$, and let $E$ be an r.i. space on $(0, \8)$. Let $E(\M)$ be the associated symmetric space of measurable operators. Then to any bounded linear map $T$ from $E(\M)$ into a Hilbert spac

Damiano Testa

We prove that the spaces of rational curves on del Pezzo surfaces are either irreducible or empty, with a unique exception.

Sylvain Rubenthaler, Tobias Rydén, Magnus Wiktorsson

Using classical simulated annealing to maximise a function $ψ$ defined on a subset of $\R^d$, the probability $\p(ψ(θ\_n)\leq ψ\_{\max}-ε)$ tends to zero at a logarithmic rate as $n$ increases; here $θ\_n$ is the state in the $n$-th stage of the simulated annealing algorithm and $ψ\_{\max}$ is the maximal value of $ψ$. We propose a modified scheme for which

Andrzej Kucharski, Szymon Plewik

C-cross topologies are introduced. Modifcations of the Kuratowski-Ulam Theorem are considered. Cardinal invariants add, cof, cov and non with respect to meager or nowhere dense subsets are compared. Remarks on invariants cof(nwdY) are mentioned for dense subspaces Y of X.

S. Janson, R. Neininger

We study a random fragmentation process and its associated random tree. The process has earlier been studied by Dean and Majumdar (J. Phys. A: Math. Gen., vol. 35, L501--L507), who found a phase transition: the number of fragmentations is asymptotically normal in some cases but not in others, depending on the position of roots of a certain characteristic equ

Martin Kolar

The paper gives a complete description of local automorphism groups for Levi degenerate hypersurfaces of finite type in $\mathbb{C}^2$. We also prove that, with the exception of hypersurfaces of the form $v = |z|^k$, local automorphisms are always determined by 1-jets. This proves a conjecture of D. Zaitsev in the finite type case.

Yong Liu, Huaizhong Zhao

In this paper, we show the existence and uniqueness of the stationary solution $u(t,ω)$ and stationary point $Y(ω)$ of the differentiable random dynamical system $U:R\times L^2[0,1]\times Ω\to L^2[0,1]$ generated by the stochastic Burgers equation with $L^2[0,1]$-noise and large viscosity, especially, $u(t,ω)=U(t,Y(ω),ω)=Y(θ(t,ω))$, and $Y(ω) \in H^1[0,1]$ i

Elemer E. Rosinger

Several thoughts are presented on the long ongoing difficulties both students and academics face related to Calculus 101. Some of these thoughts may have a more general interest.

Jan Lorenz

We present a results about convergence of products of row-stochastic matrices which are infinite to the left and all have positive diagonals. This is regarded as in inhomogeneous consensus process where confidence weights may change in every time step but where each agent has a little bit of self confidence. The positive diagonal leads to a fixed zero patter

U. Christ, J. Lohkamp

The paper introduces a number of new techniques to handle minimal hyersurface singularities. In particular, they allow to extend the obstruction theory for postive scalr curvature to any dimension.

Bernard Helffer, Yuri A. Kordyukov

We show that, under some very weak assumption of effective variation for the magnetic field, a periodic Schrödinger operator with magnetic wells on a noncompact Riemannian manifold $M$ such that $H^1(M, \R)=0$ equipped with a properly disconnected, cocompact action of a finitely generated, discrete group of isometries has an arbitrarily large number of spect

Yuxiang Li

In a previous paper, the author proved the existence of extremal function for the Moser-Trudinger inequality on a compact manifold. In the this paper, we will give a new proof of one of the key proposition.

Scott Sheffield

We study "random surfaces," which are random real (or integer) valued functions on Z^d. The laws are determined by convex, nearest neighbor, difference potentials that are invariant under translation by a full-rank sublattice L of Z^d; they include many discrete and continuous height models (e.g., domino tilings, square ice, the harmonic crystal, the

D. G. Coyne, D. C. Cheng

A previously used quantization mechanism is applied to the continuous states of the shielded strong gravity scenario (hep-th/0602183), yielding two types of spectra for uncharged black hole scalars. Each yields the general morphology for states expected in this scenario at LHC and at arbitrarily higher energies, once the parameters are determined by the two

Aram A. Saharian

We apply the generalized Abel-Plana formula for the investigation of one-loop quantum effects on manifolds with boundaries. This allows to extract from the vacuum expectation values of local physical observables the parts corresponding to the geometry without boundaries and to present the boundary-induced parts in terms of integrals strongly convergent for t

R. Parthasarathy, Alok Kumar

The one-loop effective energy density of a pure SU(2) Yang-Mills theory in the Savvidy background, at finite temperature and chemical potential is examined with emphasis on the unstable modes. After identifying the stable and unstable modes, the stable modes are treated in the quadratic approximation. For the unstable modes, the full expansion including the

G. Lopez Castro, J. Pestieau

We propose some empirical formulae relating the masses of the heaviest particles in the standard model (the W,Z,H bosons and the t quark) to the charge of the positron $e$ and the Higgs condensate v. The relations for the masses of gauge bosons m_W = (1+e)v/4 and m_Z=sqrt{(1+e^2)/2}*(v/2) are in excellent agreement with experimental values. By requiring the

Lorenzo Ravagli

In this thesis work we have employed two microscopic models (ladder-QCD and Nambu-Jona-Lasinio) for describing the properties of the QCD phase diagram at finite temperature and quark densities. In particular, we have studied the mechanism of meson condensation at finite isospin and strangeness chemical potentials, and its competition with ``standard'&#39

Stefano Forte, Yuji Goto

We review recent experimental and theoretical progress in spin physics, as presented in the spin parallel session of DIS2006. In particular, we discuss the status of the nucleon spin structure, transverse polarized asymmetries, and recent developments such as DVCS, polarized fragmentation and polarized resummation.

M. A. Gomshi Nobary, B. Nikoobakht

The Fermi motion effect in $J/ψ$ production in various hadron colliders is studied. We deduce that in agreement with sum rules which the fragmentation functions should satisfy, while the effect has considerable influence on the fragmentation probabilities and the differential cross sections, the total cross sections are essentially left unchanged.

M. A. Gomshi Nobary

The triply heavy baryons are very different in their mass. They are essentially $Ω_{ccc}$, $Ω_{ccb}$, $Ω_{cbb}$ and $Ω_{bbb}$ baryons which may be produced in a $c$ or a $b$ quark fragmentation. Here we briefly review the direct fragmentation production of these states and choose $Ω_{ccc}$ and $Ω_{bbb}$ baryons as prototype of them to consider their producti

Mikhail A. Ivanov, Juergen G. Korner, Pietro Santorelli

Using our relativistic constituent quark model we present results on the exclusive nonleptonic and semileptonic decays of the Bc-meson. The nonleptonic decays are studied in the framework of the factorization approximation. We calculate the branching ratios for a large set of exclusive nonleptonic and semileptonic decays of the Bc-meson and compare our resul

R. L. Thews

The contrast between model predictions for the transverse momentum spectra of J/Psi observed in Au-Au collisions at RHIC is extended to include effects of nuclear absorption. We find that the difference between initial production and recombination is enhanced in the most central collisions. Models utilizing a combination of these sources may eventually be ab

R. S. Raghavan

Monoenergetic antineutrinos emitted in the bound state beta-decay of H can be resonantly captured in 3He. Favorable conditions are offered by tritide technology for ultra sharp recoilless resonant capture of the 18.6 keV nubare with sigma~5x10-32 cm2, 11 orders of magnitude larger than sigma(nubare +p). The gravitational red shift of neutrinos and the mixing

Faisal Akram, Haris Rashid

We have studied the equalization of the response functions of the SK and SNO for total event rate and event rate for the energy bins. To calculate the response functions of SNO, we have used the latest theoretical values of the cross section of the neutrino-deuteron CC process. By using these new theoretical values, we find that the trigger threshold of the

T. Chiarappa, K. Jansen, K. -I. Nagai, M. Papinutto

We present a comparison of a number of iterative solvers of linear systems of equations for obtaining the fermion propagator in lattice QCD. In particular, we consider chirally invariant overlap and chirally improved Wilson (maximally) twisted mass fermions. The comparison of both formulations of lattice QCD is performed at four fixed values of the pion mass

Tomasz Korzec, Ulli Wolff

We introduce a finite volume renormalization scheme for the N-Majorana-component O(N) invariant Gross-Neveu model. Universal observables are defined that are accessible to precise numerical simulation in various discretizations and allow for an extrapolation to the continuum limit. Here first numerical results with Wilson fermions are reported. For N=2 they

Harvey B. Meyer, Oliver Witzel

A status report is presented on the large-volume simulations in the Schroedinger functional with two flavours of O(a) improved Wilson quarks performed by the ALPHA collaboration. The physics goal is to set the scale for the computation of the fundamental parameters of QCD. In this talk the emphasis is on aspects of the Hybrid Monte-Carlo algorithm, which we

Jacques Bloch, Tilo Wettig

In this talk we present the results published recently in Ref. [1], where we showed how to introduce a quark chemical potential in the overlap Dirac operator. The resulting operator satisfies a Ginsparg-Wilson relation and has exact zero modes. It is no longer gamma_5-Hermitian, but its nonreal eigenvalues still occur in pairs. We compute the spectral densit

David Garfinkle

Research Briefs: Singularity Avoidance in Canonical Quantum Gravity, by Viqar Husain What's New in LIGO, by David Shoemaker Conference reports: Scanning New Horizons: GR Beyond 4 dimensions, by Donald Marolf Quantum Gravity in the Americas III, by Jorge Pullin New Frontiers in Numerical Relativity, by Luciano Rezzolla Teaching General Relativity to Under

Shi Xiao, Gaoxi Xiao

Being motivated by recent developments in the theory of complex networks, we examine the robustness of communication networks under intentional attack that takes down network nodes in a decreasing order of their nodal degrees. In this paper, we study two different effects that have been largely missed in the existing results: (i) some communication networks,

Yoo Chul Chung, Dongman Lee

A ubiquitous computing environment consists of many resources that need to be identified by users and applications. Users and developers require some way to identify resources by human readable names. In addition, ubiquitous computing environments impose additional requirements such as the ability to work well with ad hoc situations and the provision of name

C. A. Stafford, F. Kassubek, J. Bürki, H. Grabert

Convergent semiclassical trace formulae for the density of states and cohesive force of a narrow constriction in an electron gas, whose classical motion is either chaotic or integrable, are derived. It is shown that mode quantization in a metallic point contact or nanowire leads to universal oscillations in its cohesive force: the amplitude of the oscillatio

John J. Drozd, Colin Denniston

We use simulations to investigate collision time distributions as one approaches the static limit of steady-state flow of dry granular matter. The collision times fall in a power-law distribution with an exponent dictated by whether the grains are ordered or disordered. Remarkably, the exponents have almost no dependence on dimension. We are also able to res

T. T. Fister, G. T. Seidler, C. Hamner, J. O. Cross

We report new measurements and calculations of the non-resonant inelastic x-ray scattering (NRIXS) from Mg and Al for a wide range of momentum transfers, q. Extended oscillations in the dynamic structure factor S(q,w) due to scattering from the 2p and 2s orbitals (i.e. L-edges) are observed out to more than 150 eV past the binding energy. These results are d

Dennis P. Clougherty

Using a semiclassical continuum model of an electron in a deformable molecular crystal, some properties of multicomponent generalizations of the polaron--``vector polarons''-- are elucidated. Analytical solutions for the case of two electronic bands coupled to two vibrational modes are given in detail. Within the model considered, the vector polaron

Laurent Ponson, Daniel Bonamy, Luc Barbier

Roughness of i-AlPdMn cleaved surfaces are presently analysed. From the atomic scale to 2-3 nm, they are shown to exhibit scaling properties hiding the cluster (0.45 nm) aperiodic structure. These properties are quantitatively similar to those observed on various disordered materials, albeit on other ranges of length scales. These properties are interpreted

C. D. Pemmaraju, T. Archer, D. Sanchez-Portal, S. Sanvito

We present an atomic orbital based approximate scheme for self-interaction correction (SIC) to the local density approximation of density functional theory. The method, based on the idea of Filippetti and Spaldin [Phys. Rev. B 67, 125109 (2003)], is implemented in a code using localized numerical atomic orbital basis sets and is now suitable for both molecul

Anandamohan Ghosh, Deepak Dhar, Jesper Lykke Jacobsen

We study tilings of the square lattice by linear trimers. For a cylinder of circumference m, we construct a conserved functional of the base of the tilings, and use this to block-diagonalize the transfer matrix. The number of blocks increases exponentially with m. The dimension of the ground-state block is shown to grow as (3 / 2^{1/3})^m. We numerically dia

Isaschar Genish, Lior Klein, James W. Reiner, M. R. Beasley

We have measured the planar Hall effect in epitaxial thin films of the itinerant ferromagnet SrRuO3 patterned with their current paths at different angles relative to the crystallographic axes. Based on the results, we have determined that SrRuO3 exhibits small resistivity anisotropy in the entire temperature range of our measurements (between 2 to 300 K); n

Natascia Andrenacci, Federico Corberi, Eugenio Lippiello

We study the phase-ordering kinetics following a quench to a final temperature $T_f$ of the one-dimensional p-state clock model. We show the existence of a critical value $p_c=4$, where the properties of the dynamics change. At $T_f=0$, for $p\le p_c$ the dynamics is analogous to that of the kinetic Ising model, characterized by Brownian motion and annihilat

Zorica Konstantinovic, Montserrat Garcia del Muro, Manuel Varela, Xavier Batlle

Thin films consisting of Ag and Au nanoparticles embedded in amorphous ZrO2 matrix were grown by pulsed laser deposition in a wide range of metal volume concentrations in the dielectric regime (0.08<x(Ag)<0.28 and 0.08<x(Au)<0.52). High resolution transmission electron microscopy (TEM) showed regular distribution of spherical Au and Ag nanoparticles having v

J. M. Speight

The dynamics of magnetic bubble solitons in a two-dimensional isotropic antiferromagnetic spin lattice is studied, in the case where the exchange integral J(x,y) is position dependent. In the near continuum regime, this system is described by the relativistic O(3) sigma model on a spacetime with a spatially inhomogeneous metric, determined by J. The geodesic

A. De Col, G. I. Menon, G. Blatter

We study the melting of the pancake vortex lattice in a layered superconductor in the limit of vanishing Josephson coupling. Our approach combines the methodology of a recently proposed mean-field substrate model for such systems with the classical density functional theory of freezing. We derive a free-energy functional in terms of a scalar order-parameter

T. Susaki, N. Nakagawa, H. Y. Hwang

We have found that the current- voltage characteristics of La0.7Sr0.3MnO3(-delta)/Nb:SrTiO3 rectifying junctions are quantitatively well-described by (thermally-assisted) tunneling with an effectively temperature-independent Schottky barrier under no magnetic field, while those of the oxygen deficient junction remarkably deviate from such a simple behavior a

J. A. M. Huhtamäki, M. Möttönen, S. M. M. Virtanen

Multiquantum vortices in dilute atomic Bose-Einstein condensates confined in long cigar-shaped traps are known to be both energetically and dynamically unstable. They tend to split into single-quantum vortices even in the ultralow temperature limit with vanishingly weak dissipation, which has also been confirmed in the recent experiments [Y. Shin et al., Phy

A. Honecker, D. C. Cabra, H. -U. Everts, P. Pujol

We investigate the classical counterpart of an effective Hamiltonian for a strongly trimerized kagome lattice. Although the Hamiltonian only has a discrete symmetry, the classical groundstate manifold has a continuous global rotational symmetry. Two cases should be distinguished for the sign of the exchange constant. In one case, the groundstate has a 120^\c

W. Yang, Kai Chang

We find that the Rashba spin splitting is intrinsically a nonlinear function of the momentum, and the linear Rasha model may overestimate it significantly, especially in narrow-gap materials. A nonlinear Rashba model is proposed, which is in good agreement with the numerical results from the eight-band kp theory. Using this model, we find pronounced suppress

J. Zou, I. Sosnin, P. Virtanen, M. Meschke

The thermopower of mesoscopic normal metal/superconductor structures has been measured at low temperatures. Effect of supercurrent present in normal part of the structure was studied in two cases: when it was created by applied external magnetic field and when it was applied directly using extra superconducting electrodes. Temperature and magnetic field depe

Walter M. Weber, Georg S. Duesberg, Andrew P. Graham, Maik Liebau

Nominally undoped silicon nanowires (NW) were grown by catalytic chemical vapor deposition. The growth process was optimized to control the NWs diameters by using different Au catalyst thicknesses on amorphous SiO2, Si3N4, or crystalline-Si substrates. For SiO2 substrates an Ar plasma treatment was used to homogenize the catalyst coalescence, and thus the NW

J. W. Loram, J. L. Tallon

Scanning tunneling spectroscopy studies on Bi$_2$Sr$_2$CaCu$_2$O$_{8+δ}$ suggest the presence of electronic inhomogeneity with a large spatial variation in gap size. Andersen {\it et al} have modelled this variation by assuming a spatially-varying pairing interaction. We show that their calculated specific heat is incompatible with the experimental data whic

T. Kimura, Y. Otani, T. Sato, S. Takahashi

Reversible spin Hall effect comprising the &#34;direct&#34; and &#34;inverse&#34; spin Hall effects was successfully detected at room temperature. This experimental demonstration proves the fundamental relations called Onsager reciprocal relations between spin and charge currents. A platinum wire with a strong spin-orbit interaction is used not only as a spi

D. X. Yao, E. W. Carlson

Recent neutron scattering measurements reveal spin and charge ordering in the half-doped nickelate, La$_{3/2}$ Sr$_{1/2}$ NiO$_4$. Many of the features of the magnetic excitations have been explained in terms of the spin waves of diagonal stripes with weak single-ion anisotropy. However, an optical mode dispersing away from the (π,π) point was not captured b

P. G. Silvestrov

The density of states in the semiclassical Andreev billiard is theoretically studied and shown to be determined by the fluctuations of the classical Lyapunov exponent $λ$. The rare trajectories with a small value of $λ$ give rise to an anomalous increase of the Ehrenfest time $τ_E\approx |\ln\hbar|/λ$ and, consequently, to the appearance of Andreev levels wi

Alexander Kusenko

Sterile neutrinos with masses in the keV range can be the dark matter, and their emission from a supernova can explain the observed velocities of pulsars. The sterile neutrino decays could produce the x-ray radiation in the early universe, which could have an important effect on the formation of the first stars. X-rays could ionize gas and could catalyze the

A. J. Barger, L. L. Cowie, W. -H. Wang

We use highly spectroscopically complete observations of the radio sources from the VLA 1.4 GHz survey of the HDF-N region to study the faint radio galaxy population and its evolution. We spectrally classify the sources into four spectral types: absorbers, star formers, Seyfert galaxies, and broad-line AGNs, and we analyze their properties by type. We supple

A. Kogut, D. Fixsen, S. Fixsen, S. Levin

The Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission (ARCADE) is a balloon-borne instrument designed to measure the temperature of the cosmic microwave background at centimeter wavelengths. ARCADE searches for deviations from a blackbody spectrum resulting from energy releases in the early universe. Long-wavelength distortions in the CMB

John M. Carpenter, Eric E. Mamajek, Lynne A. Hillenbrand, Michael R. Meyer

We present 4.5, 8, and 16um photometry from the Spitzer Space Telescope for 204 stars in the Upper Scorpius OB Association. The data are used to investigate the frequency and properties of circumstellar disks around stars with masses between ~ 0.1 and 20 Msun at an age of ~ 5 Myr. We identify 35 stars that have emission at 8um or 16um in excess of the stella

Andres Jordan, Dean E. McLaughlin, Patrick Cote, Laura Ferrarese

We present results from a study of the globular cluster luminosity function (GCLF) in a sample of 89 early-type galaxies observed as part of the ACS Virgo Cluster Survey. Using a Gaussian parametrization of the GCLF, we find a highly significant correlation between the GCLF dispersion, sigma, and the galaxy luminosity, M_B, in the sense that the GC systems i

Pavel Kroupa

Star clusters are observed to form in a highly compact state and with low star-formation efficiencies, and only 10 per cent of all clusters appear to survive to middle- and old-dynamical age. If the residual gas is expelled on a dynamical time the clusters disrupt. Massive clusters may then feed a hot kinematical stellar component into their host-galaxy&#39;

Ben Davies, Jorick S. Vink, Rene D. Oudmaijer

The topic of wind-clumping has been the subject of much activity in recent years, due to the impact that it can have on derived mass-loss rates. Here we present an alternative method of investigating wind-clumping, that of polarimetry. We present simulations of the polarization produced by a clumpy wind, and argue that the observations may be reproduced just

M. R. Burleigh, E. Hogan, P. D. Dobbie, R. Napiwotzki

We present a near-infrared spectrum of the close, detached white dwarf + brown dwarf binary WD0137-349 (Maxted et al 2006), that directly reveals the substellar companion through an excess of flux longwards of 1.95 microns. We best match the data with a white dwarf + L8 composite model. For ages ~1 Gyr, the spectral type of the cool secondary is in agreement

A. C. Gonzalez-Garcia, M. Balcells, V. S. Olshevsky

We analyse the skewness of the line-of-sight velocity distributions in model elliptical galaxies built through collisionless galaxy mergers. We build the models using large N-body simulations of mergers between either two spiral or two elliptical galaxies. Our aim is to investigate whether the observed ranges of skewness coefficient (h3) and the rotational s

S. Recchi, P. Kroupa, Ch. Theis, G. Hensler

Our aim is to study the evolution of tidal dwarf galaxies. The first step is to understand whether a model galaxy without Dark Matter can sustain the feedback of the ongoing star formation. We present tests of the evolution of models in which star formation efficiency, temperature threshold, initial distribution of gas and infall are varied. We conclude that