July 2005 arXiv papers — page 3

D. J. Cirilo Lombardo

In this work a new asymptotically flat solution of the coupled Einstein-Born-Infeld equations for a static spherically symmetric space-time is obtained. When the intrinsic mass is zero the resulting spacetime is regular everywhere, in the sense given by B. Hoffmann and L. Infeld in 1937, and the Einstein-Born-Infeld theory leads to the identification of the

V. V. Kiselev

An effective action of ghost condensate with higher derivatives creates a source of gravity and mimics a dark matter in spiral galaxies. We present a spherically symmetric static solution of Einstein--Hilbert equations with the ghost condensate at large distances, where flat rotation curves are reproduced in leading order over small ratio of two energy scale

I. A. Kuchin, S. S. Boichenko, Y. I. Kuchin

The origin of self-similar (according to Y.Kulakov) structure of the Universe is discussed from a position of the theory of dynamic systems (DS). A probable nature of the isomorphism of DS configurations of different levels is revealed. Nucleon DS configuration like black hole (BH) might be acquired by the last as a result of Hawking radiation of initial BH

V. O. Soloviev

We discuss the most interesting approaches to derivation of the Bekenstein-Hawking entropy formula from a statistical theory.

A. Burinskii

Stringy and disklike sources of the rotating compact astrophysical objects are considered on the base of the Kerr geometry. It is argued that analyticity of the Kerr solutions may result the appearance of singular strings, which may be the source of two important astrophysical effects: the jets and QPOs phenomena.

Michel R. Dagenais, Karim Yaghmour, Charles Levert, Makan Pourzandi

The key to speeding up applications is often understanding where the elapsed time is spent, and why. This document reviews in depth the full array of performance analysis tools and techniques available on Linux for this task, from the traditional tools like gcov and gprof, to the more advanced tools still under development like oprofile and the Linux Trace T

Nicolai Kuntze, Thomas Rauch, Andreas U. Schmidt

Identity Management is becoming more and more important in business systems as they are opened for third parties including trading partners, consumers and suppliers. This paper presents an approach securing a system without any knowledge of the system source code. The security module adds to the existing system authentication and authorisation based on aspec

Samanta Piano, Fabrizio Bobba, Filippo Giubileo, Anna Maria Cucolo

We have performed a detailed study of the conductance characteristics obtained by point contact junctions realized between a normal Pt/Ir tip and syntered RuSr2GdCu2O8 (Ru-1212) samples. Indeed, this compound is subject of great interest due to the coexistence of both magnetic order and bulk superconductivity. In our experiments, the low temperature tunnelin

D. Blume

Bosonic two-dimensional self-bound clusters consisting of $N$ atoms interacting through additive van der Waals potentials become unbound at a critical mass m*(N); m*(N) has been predicted to be independent of the size of the system. Furthermore, it has been predicted that the ground state energy E(N) of the N-atom system varies exponentially as the atomic ma

Heiner Kohler, Fernando Sols

We study the dissipative properties of a harmonic oscillator subject to two independent heat baths, one of which couples to its position and the other one to its momentum. This model describes a large spin impurity in a ferromagnet. We find that some effects of the two heat baths partially cancel each other. Most notably, oscillations may remain underdamped

A. Donarini, T. Novotný, A. -P. Jauho

A quantum shuttle is an archetypical nanoelectromechanical device, where the mechanical degree of freedom is quantized. Using a full-scale numerical solution of the generalized master equation describing the shuttle, we have recently shown [Novotný {\it et al.}, Phys. Rev. Lett. {\bf 92}, 248302 (2004)] that for certain limits of the shuttle parameters one c

Chi-Shung Tang, Wing Wa Yu, Vidar Gudmundsson

We consider electronic transport through laterally parallel double open quantum dots embedded in a quantum wire in a perpendicular magnetic field. The coupling modes of the dots are tunable by adjusting the strength of a central barrier and the applied magnetic field. Probability density and electron current density are calculated to demonstrate transport ef

A. V. Syromyatnikov

Chiral fluctuations in triangular antiferromagnets (TAFs) at $T \ll T_N$ are studied theoretically. The case of a ferromagnetic interaction along c axis (which is directed perpendicular to the plane of the lattice), Dzyaloshinskii-Moriya interaction ${\bf D}\| c$ and a weak magnetic field ${\bf H}\| c$ is considered in detail. Previously, this model has been

A. Oleinikova, I. Brovchenko, A. Geiger

An analysis of water clustering is used to study the quasi-2D percolation transition of water adsorbed at planar hydrophilic surfaces. Above the critical temperature of the layering transition (quasi-2D liquid-vapor phase transition of adsorbed molecules) a percolation transition occurs at some threshold surface coverage, which increases with increasing temp

Vieri Mastropietro

In the [BCS] paper the theory of superconductivity was developed for the BCS model, in which the (instantaneous) interaction is only between fermions of opposite momentum and spin. Such model was analyzed by variational methods, finding that a superconducting behavior is energetically favorable. Subsequently it was claimed that in the thermodynamic limit the

M. S. Baptista, T. Pereira, J. C. Sartorelli, I. L. Caldas

We show that, in periodically perturbed chaotic systems, Phase Synchronization appears, associated to a special type of stroboscopic map, in which not only averages quantities are equal to invariants of the perturbation, the angular frequency, but also it exists a very large number of non-transient transformations, possibly infinity. In cases where there is

M. Grasso, E. Khan, M. Urban

We study the effects of superfluidity on the monopole and quadrupole collective excitations of a dilute ultra-cold Fermi gas with an attractive interatomic interaction. The system is treated fully microscopically within the Bogoliubov-de Gennes and quasiparticle random-phase approximation methods. The dependence on the temperature and on the trap frequency i

P. B. Stiffell, M. J. Everitt, T. D. Clark, C. J. Harland

In this paper we study, by analogy with quantum optics, the superconducting quantum interference device (SQUID) ring mediated quantum mechanical interaction of an input electromagnetic field oscillator mode with two or more output oscillator modes at subintegers of the input frequency. We show that through the nonlinearity of the SQUID ring multiphoton downc

G. E. Astrakharchik

The knowledge of a series expansion of the equation of state provides a deep insight into the physical nature of a quantum system. Starting from a generic ``perturbative'' equation of state of a homogeneous ultracold gas we make predictions for the properties of the gas in the presence of harmonic confinement. The local density approximation is used

Markus Brede, Sitabhra Sinha

We investigate the role of degree correlation among nodes on the stability of complex networks, by studying spectral properties of randomly weighted matrices constructed from directed Erdös-Rényi and scale-free random graph models. We focus on the behaviour of the largest real part of the eigenvalues, $λ_\text{max}$, that governs the growth rate of perturbat

A. S. Moskvin, S. -L. Drechsler, R. Hayn, J. Málek

A semi-quantitative cluster approach is developed to describe the charge transfer (CT) electron-hole excitations in insulating cuprates in a rather wide energy range up to 10- 15 eV. It generalizes the Zhang-Ng (ZN) model of CT excitons by considering the complete set of Cu3d and O2p orbitals within the CuO4 embedded molecular cluster method and by introduci

R. J. Epstein, F. M. Mendoza, Y. K. Kato, D. D. Awschalom

The nitrogen-vacancy (N-V) center in diamond is a promising atomic-scale system for solid-state quantum information processing. Its spin-dependent photoluminescence has enabled sensitive measurements on single N-V centers, such as: electron spin resonance, Rabi oscillations, single-shot spin readout and two-qubit operations with a nearby 13C nuclear spin. Fu

A. S. Moskvin

We develop a model approach to describe charge fluctuations and different charge phases in strongly correlated 3d oxides. As a generic model system one considers that of centers each with three possible valence states described in frames of pseudo-spin (isospin) formalism by an effective anisotropic non-Heisenberg Hamiltonian. Simple uniform mean-field phase

S. L. Ginzburg, A. V. Nakin, N. E. Savitskaya

We give a theoretical description of avalanche-like dynamics of magnetic flux in the critical state of "hard" type-II superconductors using a model of a one-dimensional multijunction SQUID that well reproduces the main magnetic properties of these objects. We show that the system under consideration demonstrates the self-organized criticality. The av

Sooa Park, S. -R. Eric Yang

We investigate theoretically spin and orbital pseudospin magnetic properties of a molecular orbital in parabolic and elliptic double quantum dots (DQDs). In our many body calculation we include intra- and inter-dot electron-electron interactions, in addition to the intradot exchange interaction of `p' orbitals. We find for parabolic DQDs that, except for

Dariush Heidarian, Mustansir Barma, Nandini Trivedi

We show that the effect of disorder on a Mott-Hubbard insulator of interacting electrons produces a quantum phase transition from an antiferromagnetic to a paramagnetic phase governed by a percolation of the singly occupied weakly disordered sites. Near the transition, we propose that a new type of defect, formed by the resonant exchange between a spin singl

Ali Javey, Hongjie Dai

A novel method is developed to enable the formation, positioning and patterning of individual metal nano-clusters with controllable and monodispersed sizes down to 1-2 nm-scale. Among wide range of potential applications, the nanoparticle arrays are used for deterministic synthesis of monodispersed single walled carbon nanotubes. The carbon nanotubes are gro

N. P. Stern, M. Poggio, M. H. Bartl, E. L. Hu

We use time-resolved Faraday rotation to measure coherent spin dynamics in colloidal CdSe quantum dots charged in an electrochemical cell at room temperature. Filling of the 1Se electron level is demonstrated by the bleaching of the 1Se-1S3/2 absorption peak. One of the two Lande g-factors observed in uncharged quantum dots disappears upon filling of the 1Se

Yu. V. Pershin, C. Piermarocchi

We propose a scheme for the generation of photocurrent in bent quantum wires. We calculate the current using a generalized Landauer-Buttiker approach that takes into account the electromagnetic radiation. For circularly polarized light, we find that the curvature in the bent wire induces an asymmetry in the scattering coefficients for left and right moving e

Massimo Rontani, Elisa Molinari

We demonstrate that in semiconductor quantum dots wave functions probed by imaging techniques based on local tunneling spectroscopies like STM show characteristic signatures of electron-electron Coulomb correlation. We predict that such images correspond to ``quasi-particle'' wave functions which cannot be computed by standard mean-field techniques (

M. Hoinkis, M. Sing, J. Schaefer, M. Klemm

We have studied the electronic structure of the spin-1/2 quantum magnet TiOCl by polarization-dependent momentum-resolved photoelectron spectroscopy. From that, we confirm the quasi-one-dimensional nature of the electronic structure along the crystallographic b-axis and find no evidence for sizable phonon-induced orbital fluctuations as origin for the non-ca

Pierfrancesco Buonsante, Alessandro Vezzani

The phase diagram of ultracold bosons in realistic optical superlattices is addressed via second-order {\it cell} strong coupling perturbative expansions for the Bose-Hubbard model describing the system. Taking advantage of the cell partition inherent in the complex periodic modulation of a superlattice, this technique allows for the description of the unusu

C. Fusco, A. Fasolino

The motion of molecules on solid surfaces is of interest for technological applications, but it is also a theoretical challenge. We study the deterministic and thermal diffusive dynamics of a dimer moving on a periodic substrate. The deterministic motion of the dimer displays strongly nonlinear features and chaotic behavior. The dimer thermal diffusive dynam

Laura Magrini, Pierre Leisy, Romano L. M. Corradi, Mario Perinotto

Spectroscopic observations obtained with the VLT of one planetary nebula (PN) in Sextans A and of five PNe in Sextans B and of several HII regions (HII) in these two dwarf irregular galaxies are presented. The extended spectral coverage, from 320.0 to 1000.0nm, and the large telescope aperture allowed us to detect a number of emission lines, covering more th

Jeremy R. King, Ann M. Boesgaard, Simon C. Schuler

We use high S/N, high-resolution Keck/HIRES spectroscopy of 4 solar twin candidates (HIP 71813, 76114, 77718, 78399) from our Hipparcos-based CaII H & K survey to carry out parameter and abundance analyses of these objects. Our spectroscopic Teff estimates are some 100 K hotter than the photometric scale of the recent Geneva-Copenhagen survey; several lines

J. P. Willis, F. Pacaud, I. Valtchanov, M. Pierre

We present X-ray and optical spectroscopic observations of twelve galaxy groups and clusters identified within the XMM Large-Scale Structure (LSS) survey. Groups and clusters are selected as extended X-ray sources from a 3.5 deg2 XMM image mosaic above a flux limit 8e-15 ergs/s/cm2 in the [0.5-2] keV energy band. Deep BVRI images and multi-object spectroscop

Yong-Seon Song, Wayne Hu

An alternative mechanism that dims high redshift supernovae without cosmic acceleration utilizes an oscillation of photons into a pseudo-scalar particle during transit. Since angular diameter distance measures are immune to the loss of photons, this ambiguity in interpretation can be resolved by combining CMB acoustic peak measurements with the recent baryon

Jay Strader, Jean P. Brodie, Lee Spitler, Michael A. Beasley

We have analyzed archival HST/ACS images in Sloan g and z of the globular cluster (GC) systems of 53 ellipticals in the Virgo Cluster, spanning massive galaxies to dEs. Among the new results are: (1) In the gEs M87 and NGC 4649, there is a correlation between luminosity and color for individual metal-poor GCs, such that more massive GCs are more metal-rich.

Jeremy R. King, Simon C. Schuler

We use new and extant literature spectroscopy to address abundances and membership for UMa moving group stars. We first compare the UMa, Coma, and Hyades H-R diagrams via a homogeneous set of isochrones, and find that these three aggregates are essentially coeval. Our spectroscopy of cool UMa dwarfs reveals striking abundance anomalies--trends with Teff, ion

K. Finlator, R. Dave, C. Papovich, L. Hernquist

We study the physical and photometric properties of galaxies at z=4 in cosmological hydrodynamic simulations of a lambda-CDM universe. We focus on galaxies satisfying the GOODS "B-dropout" criteria. Our goals are: (1) to study the nature of high-redshift galaxies; (2) to test the simulations against published measurements of high-redshift galaxies; (

Steven R. Cranmer

This paper presents a detailed statistical determination of the equatorial rotation rates of classical Be stars. The rapid rotation of Be stars is likely to be linked to the ejection of gas that forms dense circumstellar disks. The physical origins of these disks are not understood, though it is generally believed that the ability to spin up matter into a Ke

G. Castelletti, G. Dubner

We have conducted a study at radio wavelengths of the spectral behaviour of the supernova remnant (SNR) CTB 80. Based on an homogenised data set of integrated flux densities, we calculated for the whole SNR a radio index -0.36 +/- 0.02. The shape of the global spectrum suggests absorption by ionized gas in the interstellar medium (ISM) along the line of sigh

R. Wischnewski

The Baikal neutrino telescope NT200, operating since 1998, has been upgraded in spring 2005 to NT200+. This telescope with 3 additional outer strings at 100 m radius from the center encloses a geometric volume of 5 Mtons. We describe the modernized data acquisition and control system, which allows for higher bandwidth, full multiplexing of data and control s

R. Wischnewski

We present the results of a search for high energy extraterrestrial neutrinos with the Baikal underwater Cherenkov detector NT200, based on data taken in 1998 - 2002 (1038 live days).Upper limits on the diffuse fluxes of ν_e+ν_μ+ν_τ, predicted by several models of AGN-like neutrino sources, are derived. For an E^{-2} behavior of the neutrino spectrum, our li

J. K. Adelman-McCarthy et al.

This paper describes the fourth data release of the Sloan Digital Sky Survey (SDSS), including all survey-quality data taken through June 2004. The data release includes five-band photometric data for 180 million objects selected over 6670 deg^2, and 673,280 spectra of galaxies, quasars, and stars selected from 4783 deg^2 of that imaging data using the stand

L. Kuzmichev

The Baikal neutrino telescope NT200 takes data since 1998. In 2005, the deployment of three additional strings for common operation with NT200 was finished. We describe the physics program and the design of the new telescope named NT200+ and present selected physical results obtained with NT200. First results from NT200+ will be presented at the conference.

M. De Pasquale, L. Piro, B. Gendre, L. Amati

We present the X-ray afterglow catalog of BeppoSAX from the launch of the satellite to the end of the mission. Thirty-three X-ray afterglows were securely identified based on their fading behavior out of 39 observations. We have extracted the continuum parameters (decay index, spectral index, flux, absorption) for all available afterglows. We point out a pos

Bradley C. Whitmore, Diane Gilmore, C. Leitherer, S. Michael Fall

Long-slit spectra of several dozen young star clusters have been obtained at three positions in the Antennae galaxies with the Space Telescope Imaging Spectrograph (STIS) and its 52&#34;x0.2&#34; slit. Based on H-alpha emission-line measurements, the average cluster-to-cluster velocity dispersion in 7 different cluster aggregates (&#34;knots&#34;) is <10 \km

L. E. Allen, J. L. Hora, S. T. Megeath, L. K. Deutsch

We are conducting a survey of several regions of high-mass star formation to assess their content and structure. The observations include Spitzer observations, ground-based optical and near-IR imaging surveys, and optical and IR spectra of objects and locations in the molecular clouds. The goal of the survey is to gain a better understanding of the processes

W. J. Frith, P. J. Outram, T. Shanks

We use the 2MASS extended source catalogue to determine angular correlation functions, w_p, to high orders (p<=9). The main sample contains 650,745 galaxies and represents an order of magnitude increase in solid angle over previous samples used in such analysis. The high-order correlation functions are used to determine the projected and real space hierarchi

C. Balland, M. Mouchet, R. Pain, N. A. Walton

We present spectra of twelve Type Ia supernovae obtained in 1999 at the William Herschel Telescope and the Nordic Optical Telescope during a search for Type Ia supernovae (SN Ia) at intermediate redshift. The spectra range from z=0.178 to z=0.493, including five high signal-to-noise ratio SN Ia spectra in the still largely unexplored range 0.15 < z < 0.3. Mo

Stefano Gabici, Pasquale Blasi, Giulia Vannoni

The dynamical reaction of the particles accelerated at a shock front by the first order Fermi process can be determined within kinetic models that account for both the hydrodynamics of the shocked fluid and the transport of the accelerated particles. These models predict the appearance of multiple solutions, all physically allowed. We discuss here the role o

R. Wischnewski

New results from the Baikal neutrino telescope NT200, based on the first 5 years of operation (1998-2003), are presented. We derive an all-flavor limit on the diffuse flux of astrophysical neutrinos between 20 TeV and 50 PeV, extract an enlarged sample of high energy muon neutrino events, and obtain limits on the flux of high energy atmospheric muons. In 200

Abhas Mitra

We estimate that the vacuum electric field associated with a spinning Magnetospheric Eternally Collapsing Object MECO (www.phys.uni-sofia.bg/~astro/abbrev.html) could be higher by a factor of ~ 10^4 than the corresponding pulsar value because of extreme relativistic Frame Dragging Effect. Thus isolated spinning MECOs could be source of UHE cosmic ray acceler

S. Jancart, A. Jorissen, C. Babusiaux, D. Pourbaix

Hipparcos Intermediate Astrometric Data (IAD) have been used to derive astrometric orbital elements for spectroscopic binaries from the newly released Ninth Catalogue of Spectroscopic Binary Orbits (SB9). Among the 1374 binaries from SB9 which have an HIP entry, 282 have detectable orbital astrometric motion (at the 5% significance level). Among those, only

M. J. Hardcastle, J. H. Croston

We discuss the extended X-ray emission seen in three archival Chandra observations, and one archival XMM-Newton observation, of the FRII radio galaxy Pictor A. The overall properties of the X-ray lobes are consistent with the conclusions of earlier workers that the extended X-ray emission is largely due to the inverse-Compton process, and the implied departu

L. M. Oskinova

The Galactic center harbors some of the most massive star clusters known in the Galaxy: the Arches and the Quintuplet. Based on the Chandra observations of these clusters (PI: Wang) which recently became public, I discuss the X-ray emission from the massive stars in these clusters. Confirming the general trend for Wolf-Rayet (WR) stars being X-ray dim, none

J. -F. Giovannelli, A. Coulais

The paper deals with the construction of images from visibilities acquired using aperture synthesis instruments: Fourier synthesis, deconvolution, and spectral interpolation/extrapolation. Its intended application is to specific situations in which the imaged object possesses two superimposed components: ($i$) an extended component together with ($ii$) a set

C. Adami, A. Mazure, O. Ilbert, A. Cappi

We have used the Vimos VLT Deep Survey in combination with other spectroscopic, photometric and X-ray surveys from literature to detect several galaxy structures in the Chandra Deep Field South (CDFS). Both a friend-of-friend based algorithm applied to the spectroscopic redshift catalog and an adaptative kernel galaxy density and colour maps correlated with

N. N. Chugai, S. N. Fabrika, O. N. Sholukhova, V. P. Goranskij

The photometric and spectroscopic observations of nearby type IIP supernova 2004dj are presented. The $^{56}$Ni mass estimated from the light curve is $\approx0.02 M_{\odot}$. This estimate is found to be consistent with the H$α$ luminosity. SN2004dj reveals a strong asymmetry of the H$α$ emission line at the nebular epoch with the shift of the maximum of -1

I. Horvath, A. Meszaros, L. G. Balazs, Z. Bagoly

It is shown that in the duration-hardness plane the GRBs of the third intermediate subgroup are well defined. Their durations are intermediate (i.e. roughly between 2 and 10 seconds), but their hardnesses are the lowest. They are even softer than the long bursts.

Sergei Nayakshin, Rashid Sunyaev

Few dozens of young high mass stars orbit Sgr A* at distances as short as 0.1 parsec, where star formation should be quenched by the strong tidal shear from Sgr A*. The puzzling young stellar population is believed to come into existence in one of the two ways: (i) &#34;normal&#34; star formation at several tens of parsec in a very massive star cluster that

J. -S. Huang, D. Rigopoulou, S. P. Willner, C. Papovich

A deep mid- and far-infrared survey in the Extended Groth Strip (EGS) area gives 3.6 to 8\micron flux densities or upper limits for 253 Lyman Break Galaxies (LBGs). The LBGs are a diverse population but with properties correlated with luminosity. The LBGs show a factor of 30 range in indicated stellar mass and a factor of 10 in apparent dust content relative

E. Sasioglu, L. M. Sandratskii, P. Bruno, I. Galanakis

We study the exchange interactions in half-metallic Heusler alloys using first-principles calculations in conjunction with the frozen-magnon approximation. The Curie temperature is estimated within both mean-field (MF) and random-phase-approximation (RPA) approaches. For the half-Heusler alloys NiMnSb and CoMnSb the dominant interaction is between the neares

N. J. Nunes

The evolution of a scalar field is explored taking into account the presence of a background fluid in a positively curved Universe in the framework of loop quantum cosmology. Though the mechanism that provides the initial conditions for inflation extensively studied in the literature, is still available in this setup, it demands that the initial kinetic ener

Mason A. Porter, P. G. Kevrekidis, R. Carretero-González, D. J. Frantzeskakis

We analyze the existence and stability of bright, dark, and gap matter-wave solitons in optical superlattices. Then, using these properties, we show that (time-dependent) ``dynamical superlattices&#39;&#39; can be used to controllably place, guide, and manipulate these solitons. In particular, we use numerical experiments to displace solitons by turning on a

John Smolin, Jonathan Oppenheim

The black hole information loss paradox has plagued physicists since Hawking&#39;s discovery that black holes evaporate thermally in contradiction to the unitarity expected by quantum mechanics. Here we show that one of the central presumptions of the debate is incorrect. Ensuring that information not escape during the semi-classical evaporation process does

John Little, Hal Schenck

Toric codes are evaluation codes obtained from an integral convex polytope $P \subset \R^n$ and finite field $\F_q$. They are, in a sense, a natural extension of Reed-Solomon codes, and have been studied recently by J. Hansen and D. Joyner. In this paper, we obtain upper and lower bounds on the minimum distance of a toric code constructed from a polygon $P \

Paul R. Shapiro, Ilian T. Iliev, Marcelo A. Alvarez, Evan Scannapieco

We derive the equations for the propagation of relativistic ionization fronts in both static and moving gases. We focus on the supersonic R-type phase that occurs right after a source turns on, and we compare the nonrelativistic and relativistic solutions for several important cases. Relativistic corrections can be significant up until the light-crossing tim

J. W. Maluf, M. V. O. Veiga, J. F. da Rocha-Neto

The expression of the gravitational energy-momentum defined in the context of the teleparallel equivalent of general relativity is extended to an arbitrary set of real-valued tetrad fields, by adding a suitable reference space subtraction term. The characterization of tetrad fields as reference frames is addressed in the context of the Kerr space-time. It is

Marcus Berg, Michael Haack, Wolfgang Muck

We consider gauge/string duality (in the supergravity approximation) for confining gauge theories. The system under scrutiny is a 5-dimensional consistent truncation of type IIB supergravity obtained using the Papadopoulos-Tseytlin ansatz with boundary momentum added. We develop a gauge-invariant and sigma-model-covariant approach to the dynamics of 5-dimens

Pablo I. Hurtado

We investigate the behavior of a one-dimensional diatomic fluid under a shock wave excitation. We find that the properties of the resulting shock wave are in striking contrast with those predicted by hydrodynamic and kinetic approaches, e.g., the hydrodynamic profiles relax algebraically toward their equilibrium values. Deviations from local thermodynamic eq

G. E. Brown, Chang-Hwan Lee, Mannque Rho

The hidden local symmetry effective theory, Wilsonian matched to QCD at a matching scale near the chiral scale $\sim 4πf_π$ as formulated by Harada and Yamawaki, presents a scenario drastically different from the standard scenario of heavy-ion collisions in that as the temperature approaches the critical temperature $T_c$ of chiral restoration from below, th

J. -F. Pascual-Sanchez

Today, the Global Navigation Satellite Systems, used as global positioning systems, are the GPS and the GLONASS. They are based on a Newtonian model and hence they are only operative when several relativistic effects are taken into account. The most important relativistic effects (to order 1/c^2) are: the Einstein gravitational blue shift effect of the satel

Jelena Vuckovic, Dirk Englund, David Fattal, Edo Waks

Photonic crystal cavities can localize light into nanoscale volumes with high quality factors. This permits a strong interaction between light and matter, which is important for the construction of classical light sources with improved properties (e.g., low threshold lasers) and of nonclassical light sources (such as single and entangled photon sources) that

T. N. Leite, N. Teruya, H. Dias, .

The separation energy and half-life of some heavy proton emitting nuclei, and the single-particle structure of the unbound 11-N, have been evaluated by implementing a careful numerical treatment to solve Schrodinger equation in a continuum discretization context. The basic scheme behind the method consists in using the ground-state proton emitter in connecti

Pieter Moree

Let m>=1 be an arbitrary fixed integer and let N_m(x) count the number of odd integers u<=x such that the order of 2 modulo u is not divisible by m. In case m is prime estimates for N_m(x) were given by H. Mueller that were subsequently sharpened into an asymptotic estimate by the present author. Mueller on his turn extended the author&#39;s result to the ca

Govind S. Krishnaswami

We study a possibly integrable model of abelian gauge fields on a two-dimensional surface M, with volume form mu. It has the same phase space as ideal hydrodynamics, a coadjoint orbit of the volume-preserving diffeomorphism group of M, SDiff(M,mu). Gauge field Poisson brackets differ from the Heisenberg algebra, but are reminiscent of Yang-Mills theory on a

Andrea Mauri, Silvia Penati, Alberto Santambrogio, Daniela Zanon

In the β-deformed N=4 supersymmetric SU(N) Yang-Mills theory we study the class of operators O_J = Tr(Φ_i^J Φ_k), i\neq k and compute their exact anomalous dimensions for N,J\to\infty. This leads to a prediction for the masses of the corresponding states in the dual string theory sector. We test the exact formula perturbatively up to two loops. The consisten

A. Bonanno, G. Esposito, C. Rubano, P. Scudellaro

We show that the accelerated expansion of the Universe can be viewed as a crossover phenomenon where the Newton constant and the Cosmological constant are actually scaling operators, dynamically evolving in the attraction basin of a non-Gaussian infrared fixed point, whose existence has been recently discussed. By linearization of the renormalized flow it is

A. P. Lobanov, T. P. Krichbaum, A. Witzel, J. A. Zensus

The luminous high-redshift (z=2.17) quasar S50836+710 has been observed in October 1997 with the VSOP at 1.6 GHz and 5 GHz. We report here a previously unpublished image made from the data at 1.6 GHz and compare the structure of a relativistic jet in this quasazr at the two frequencies. We present a spectral index image tracing spectral properties of the jet

Marco Anderlini, David Guery-Odelin

Starting from a set of coupled Boltzmann equations, we investigate the thermalization of a two-species cold atomic gas confined either in a box or in an isotropic harmonic trap. We show that the thermalization times, by contrast to the collision rate, depend on the interferences between scattering partial waves. The dynamics of thermalization in a harmonic t

Rui Dong, Christina Goldschmidt, James B. Martin

In this paper we give a new example of duality between fragmentation and coagulation operators. Consider the space of partitions of mass (i.e., decreasing sequences of nonnegative real numbers whose sum is 1) and the two-parameter family of Poisson--Dirichlet distributions $\operatorname {PD}(α,θ)$ that take values in this space. We introduce families of ran

S. A. Pustilnik, A. Y. Kniazev, A. G. Pramskij

We present the results of optical spectroscopy and imaging with the SAO 6m telescope for the dwarf galaxy DDO 68 (UGC 5340 = VV 542), falling into the region of very low density of luminous (L > L*) galaxies (Lynx-Cancer void). Its deep images in V,R bands and in the narrow H-alpha-filter show that the galaxy has the very irregular morphology, with a long cu

B. Guberina, R. Horvat, H. Nikolic

We consider a holographic dark energy model, in which both the CC energy density rho_Lambda and the Newton constant G_N are varying quantities, to study the problem of setting an effective field-theory IR cutoff. Assuming that ordinary matter scales canonically, we show that the continuity equation univocally fixes the IR cutoff, provided a law of variation

Maria G. Adesso, Davide Uglietti, Rene Flukiger, Massimiliano Polichetti

We report additional experimental evidences about the presence of an universal behavior in the Field-Temperature Phase Diagram of Type II Superconductors. This behavior is characterized by a phase transition in the vortex matter between the disordered and the Bragg Glass phase. The experimental detection of a Peak Effect phenomenon has been proved to be stri

Sergiu I. Vacaru

In this paper, nonholonomic gerbes will be naturally derived for manifolds and vector bundle spaces provided with nonintegrable distributions (in brief, nonholonomic spaces). An important example of such gerbes is related to distributions defining nonlinear connection (N-connection) structures. They geometrically unify and develop the concepts of Riemann-Car

PHENIX Collaboration, S. S. Adler

J/psi production in d+Au and p+p collisions at sqrt(s_NN) = 200 GeV has been measured by the PHENIX experiment at rapidities -2.2 < y < +2.4. The cross sections and nuclear dependence of J/\psi production versus rapidity, transverse momentum, and centrality are obtained and compared to lower energy p+A results and to theoretical models. The observed nuclear

Eleftherios Papantonopoulos, Antonios Papazoglou

We study the cosmological evolution of isotropic matter on an infinitely thin conical codimension-two brane-world. Our analysis is based on the boundary dynamics of a six-dimensional model in the presence of an induced gravity term on the brane and a Gauss-Bonnet term in the bulk. With the assumption that the bulk contains only a cosmological constant Lambda

T. M. Aliev, M. Savci

The independent helicity amplitudes in the (Lambda_b -> Λl^+ l^-) decay in the standard model and its minimal extension, i.e., with the new vector type interactions, are calculated. We calculate various asymmetry parameters characterizing the angular dependence of the differential decay width for the cascade decay (Lambda_b -> Lambda(-> a+b) V^* (-> l^+ l^-)

T. Toeroek, B. Kliem

The ideal helical kink instability of a force-free coronal magnetic flux rope, anchored in the photosphere, is studied as a model for solar eruptions. Using the flux rope model of Titov & Demoulin (1999} as the initial condition in MHD simulations, both the development of helical shape and the rise profile of a confined (or failed) filament eruption (on 2002

Jürgen Gärtner, Wolfgang König, Stanislav Molchanov

We consider the parabolic Anderson problem $\partial_tu=Δu+ξ(x)u$ on $\mathbb{R}_+\times\mathbb{Z}^d$ with localized initial condition $u(0,x)=δ_0(x)$ and random i.i.d. potential $ξ$. Under the assumption that the distribution of $ξ(0)$ has a double-exponential, or slightly heavier, tail, we prove the following geometric characterization of intermittency: wi

Ratna Koley, Sayan Kar

We consider a new braneworld model with a bulk scalar field coupled to gravity. The bulk scalar action is inspired by the proposed low energy effective action around the tachyon vacuum. A class of warped geometries representing solutions of this Einstein-scalar system for a specific scalar potential is found. The geometry is non singular with a decaying warp

F. Bonetto, G. Gallavotti, A. Giuliani, F. Zamponi

The chaotic hypothesis has several implications which have generated interest in the literature because of their generality and because a few exact predictions are among them. However its application to Physics problems requires attention and can lead to apparent inconsistencies. In particular there are several cases that have been considered in the literatu

Vyjayanthi Chari, Adriano Moura

We define a family of graded restricted modules for the polynomial current algebra associated to a simple Lie algebra. We study the graded character of these modules and show that they are the same as the graded characters of certain Demazure modules. In particular, we see that the specialized characters are the same as those of the Kirillov Reshetikhin modu

Hao Cai, Nian-Ning Huang

Hamiltonian formalism of the DNLS equation with nonvanishing boundary value is developed by the standard procedure.

Allard-Jan van Marle, Norbert Langer, Guillermo Garcia-Segura

Long gamma-ray bursts are thought to be caused by a subset of exploding Wolf-Rayet stars. We argue that the circumstellar absorption lines in early supernova and in gamma-ray burst afterglow spectra may allow us to determine the main properties of the Wolf-Rayet star progenitors which can produce those two events. To demonstrate this, we first simulate the h

Pulak Ranjan Giri

We discuss Dirac equation (DE) and its solution in presence of solenoid (infinitely long) field in (3+1) dimensions. Starting with a very restricted domain for the Hamiltonian, we show that a 1-parameter family of self adjoint extensions (SAE) are necessary to make sure the correct evolution of the Dirac spinors. Within the extended domain bound state (BS) a

Alex Buchel

We point out an elementary thermodynamics fact that whenever the specific heat of a system is negative, the speed of sound in such a media is imaginary. The latter observation presents a proof of Gubser-Mitra conjecture on the relation between dynamical and thermodynamic instabilities for gravitational backgrounds with a translationary invariant horizon, pro

Sameer M. Ikhdair, Ramazan Sever

Using the Nikiforov-Uvarov method, the bound state energy eigenvalues and eigenfunctions of the PT-/non-PT-symmetric and non-Hermitian generalized Woods-Saxon (WS) potential with the real and complex-valued energy levels are obtained in terms of the Jacobi polynomials. According to the PT-symmetric quantum mechanics, we exactly solved the time-independent Sc