January 2001 arXiv papers — page 11

Masako Bando, Tatsuya Noguchi

In models with extra dimensions, branes have been usually treated as solid bodies though they are prohibited by the relativity. In the previous letter, we proposed a method of taking account of brane fluctuation by introducing Nambu-Goldstone bosons, and prove that when a tension of the brane is small, the interaction between boundary fields and Kaluza-Klein

M. Alford, S. Chandrasekharan, J. Cox, U. -J. Wiese

Monte Carlo simulations of lattice QCD at non-zero baryon chemical potential $μ$ suffer from the notorious complex action problem. We consider QCD with static quarks coupled to a large chemical potential. This leaves us with an SU(3) Yang-Mills theory with a complex action containing the Polyakov loop. Close to the deconfinement phase transition the qualitat

K. Kinoshita

The Belle detector at KEKB has collected 6.2 fb^{-1} of data at the Upsilon(4S) resonance. Presented here are preliminary measurements, from this data sample, of sin(2phi_1) and other quantities relating to CP.

R. A. Briere, CLEO Collaboration

We have studied two-body charmless hadronic decays of $B$ mesons into the final states phi K and phi K^*. Using 9.7 million $B\bar{B}$ pairs collected with the CLEO II detector, we observe the decays B- -> phi K- and B0 -> phi K*0 with the following branching fractions: BR(B- -> phi K-)=(5.5 +2.1-1.8 +- 0.6) x 10^{-6} and BR(B0 -> phi K*0)=(11.5 +4.5-3.7 +1.

E. Klempt

Lattice gauge calculations predict the existence of glueballs. In particular a scalar glueball is firmly expected at a mass of about 1730 MeV. This prediction has led to an intense study of scalar isoscalar interactions and to the discovery of new meson resonances. The number of scalar states observed seems to exceed the number of states which can be accommo

D. Petroff, R. Meinel

Using the analytic, global solution for the rigidly rotating disc of dust as a starting point, an iteration scheme is presented for the calculation of an arbitrary coefficient in the post-Newtonian (PN) approximation of this solution. The coefficients were explicitly calculated up to the 12th PN level and are listed in this paper up to the 4th PN level. The

Luca Bombelli

I describe the first steps in the construction of semiclassical states for non-perturbative canonical quantum gravity using ideas from classical, Riemannian statistical geometry and results from quantum geometry of spin network states. In particular, I concentrate on how those techniques are applied to the construction of random spin networks, and the calcul

Steven J. Benson, Lois Curfman McInnes, Jorge J. Moré

GPCG is an algorithm within the Toolkit for Advanced Optimization (TAO) for solving bound constrained, convex quadratic problems. Originally developed by More' and Toraldo, this algorithm was designed for large-scale problems but had been implemented only for a single processor. The TAO implementation is available for a wide range of high-performance arc

Ulrich Ultes-Nitsche, Pierre Wolper

This paper is motivated by the fact that verifying liveness properties under a fairness condition is often problematic, especially when abstraction is used. It shows that using a more abstract notion than truth under fairness, specifically the concept of a property being satisfied within fairness can lead to interesting possibilities. Technically, it is firs

P. G. Pagliuso, C. Petrovic1, R. Movshovich, D. Hall

We report a thermodynamic and transport study of the phase diagram of CeRh1-xIrxIn5. Superconductivity is observed over a broad range of doping, 0.3 < x < 1, including a substantial range of concentration (0.3 < x <0.6) over which it coexists with magnetic order (which is observed for 0 < x < 0.6). The anomalous transition to zero resistance that is observed

P. Punyindu, Z. Toroczkai, S. Das Sarma

We study, through large scale stochastic simulations using the noise reduction technique, a large number of simple nonequilibrium limited mobility solid-on-solid growth models. We find that d=2+1 dimensional surface growth in several noise reduced models (most notably the Wolf-Villain and the Larger-Curvature model) exhibits spectacular quasi-regular mound f

Joachim Brand, William P. Reinhardt

We propose a simple stirring experiment to generate quantized ring currents and solitary excitations in Bose-Einstein condensates in a toroidal trap geometry. Simulations of the 3D Gross-Pitaevskii equation show that pure ring current states can be generated efficiently by adiabatic manipulation of the condensate, which can be realized on experimental time s

John Baker, A. G. Rojo

We consider the Coulomb drag between two metal rings in which the long range Coulomb interaction leads to the formation of a Wigner crystal. The first ring is threaded by an Ahranov Bohm flux creating a persistent current J_0. The second ring is brought in close proximity to the second and due to the Coulomb interaction between the two rings a drag current J

I. Ispolatov, E. G. D. Cohen

Two examples of Microcanonical Potts models, 2-dimensional nearest neighbor and mean field, are considered via exact enumeration of states and analytical asymptotic methods. In the interval of energies corresponding to a first order phase transition, both of these models exhibit a convex dip in the entropy vs energy plot and a region with negative specific h

S. Giovanazzi, G. Kurizki, I. E. Mazets, S. Stringari

We investigate the collective excitations of an atomic Bose-Einstein condensate in the self-binding regime produced by electromagnetically induced ``gravity&#39;&#39; (1/r attraction). Analytical expressions for the frequencies of the monopole and quadrupole modes are obtained at zero temperature, using the sum-rule approach, and compared with the exact resu

S. H. Yook, H. Jeong, A. -L. Barabasi, Y. Tu

Many biological, ecological and economic systems are best described by weighted networks, as the nodes interact with each other with varying strength. However, most network models studied so far are binary, the link strength being either 0 or 1. In this paper we introduce and investigate the scaling properties of a class of models which assign weights to the

J. D. Munoz, A. R. Lima

In this work we investigate the classical ferromagnetic XY-model in two dimensions subject to a symmetry breaking field which impose a $Z_2$ symmetry to the system. We used the broad histogram method combined with microcanonical simulations and finite-size scaling analysis to estimate the critical temperature and critical exponents of this system with little

D. A. Hendrix, C. Jarzynski

Let Delta F be the free energy difference between two equilibrium states of a system. An established method of numerically computing Delta F involves a single, long ``switching simulation&#39;&#39;, during which the system is driven reversibly from one state to the other (slow growth, or adiabatic switching). Here we study a method of obtaining the same resu

Sung Jong Lee, Bongsoo Kim, Jong-Rim Lee

We present Monte Carlo simulation results on the equilibrium relaxation dynamics in the two dimensional lattice Coulomb gas, where finite fraction $f$ of the lattice sites are occupied by positive charges. In the case of high order rational values of $f$ close to the irrational number $1-g$ ($g\equiv(\sqrt{5} -1)/2$ is the golden mean), we find that the syst

Luca Leuzzi, Theo M. Nieuwenhuizen

A model glass is considered with one type of fast ($β$-type) of processes, and one type of slow processes ($α$-type). On time-scales where the fast ones are in equilibrium, the slow ones have a dynamics that resembles the one of facilitated spin models. The main features are the occurrence of a Kauzmann transition, a Vogel-Fulcher-Tammann-Hesse behaviour for

M. J. Hogg, F. Kahlmann, E. J. Tarte, Z. H. Barber

We have performed V-I measurements on a thin film YBa2Cu3O7 4^o [001] tilt low angle grain boundary over an extensive range of temperature and field, verifying the presence of a linear characteristic. We report on the occurrence of the linear characteristic in its basic form and on the observation of V-I kinking into several, and in some cases numerous, line

Z. V. Popovic, V. A. Ivanov, M. J. Konstantinovic, A. Cantarero

We have investigated the electronic structure of the zigzag ladder (chain) compound SrCuO2 combining polarized optical absorption, reflection, photoreflectance and pseudo-dielectric function measurements with the model calculations. These measurements yield an energy gap of 1.42 eV (1.77 eV) at 300 K along (perpendicular) to the Cu-O chains. We have found th

U. Lundin, I. Sandalov, O. Eriksson

We show that the formally exact expression for the free energy (with a non-relativistic Hamiltonian) for the correlated metal generates the Poisson equation within the saddle-point approximation for the electric potential, where the charge density automatically includes correlations. In this approximation the problem is reduced to the self-consistent periodi

A. J. Webster, M. E. Cates

In the absence of coalescence, coarsening of emulsions (and foams) is controlled by molecular diffusion of dispersed phase between droplets/bubbles. Studies of dilute emulsions have shown how the osmotic pressure of a trapped species within droplets can ``osmotically stabilise&#39;&#39; the emulsion. Webster and Cates (Langmuir, 1998, 14, 2068-2079) gave rig

Sandro Stringari

Bose-Einstein condensates confined in traps exhibit unique features which have been the object of extensive experimental and theoretical studies in the last few years. In this paper I will discuss some issues concerning the behaviour of the order parameter and the dynamic and superfluid effects exhibited by such systems.

Peter F. Arndt, Vladimir Rittenberg

We further study the stochastic model discussed in Ref.[2] in which positive and negative particles diffuse in an asymmetric, CP invariant way on a ring. The positive particles hop clockwise, the negative counter-clockwise and oppositely-charged adjacent particles may swap positions. We extend the analysis of this model to the case when the densities of the

K. Goral, Berthold-Georg Englert, K. Rzazewski

We investigate the properties of a degenerate dilute gas of neutral fermionic particles in a harmonic trap that interact via dipole-dipole forces. We employ the semiclassical Thomas-Fermi method and discuss the Dirac correction to the interaction energy. A nearly analytic as well as an exact numerical minimization of the Thomas-Fermi-Dirac energy functional

L. V. E. Koopmans, the CLASS collaboration

One of the main objectives of the Cosmic Lens All-Sky Survey (CLASS) collaboration has been to find gravitational lens (GL) systems at radio wavelengths that are suitable for the determination of time delays between image pairs. The survey is now near completion and at least 18 GL systems have been found. Here, I will discuss our efforts to measure time dela

Richard S Ellis

Studies of galaxy evolution at optical and near-infrared wavelengths have reached an interesting point in their historical development and the arrival of a new millenium provides an appropriate occasion to review the overall direction in which this subject is moving. The aim of this short essay is to emphasize the qualitatively different datasets now arrivin

N. J. Rodriguez-Fernandez, J. Martin-Pintado

The Infrared Space Observatory (ISO) has shown the complexity of the Galactic center (GC) Interstellar medium (ISM) detecting, not only large column densities of warm molecular gas (H2), but the emission of neutral atoms and ions of low ionization potential (CII, OI, SiII,...) that should arise in shocked or photon-dominated regions (PDRs). In addition, ISO

A. Marco, I. Negueruela, G. Bernabeu

We present uvby-beta CCD photometry of the field of the open cluster NGC 1893. Our photometry is deep enough to cover the complete main sequence B spectral type. We identify ~50 very likely members of the cluster down to spectral type B9-A0, some of which have much higher reddenings than the average. We derive a color excess E(b-y) = 0.33+-0.03 and a deredde

S. Nagataki, K. Kohri

We have studied whether the rotation and magnetic fields in neutrino-driven winds can be key processes for the rapid-process (r-process) nucleosynthesis. We have examined the features of a steady and subsonic wind solutions which extend the model of Weber and Davis (1967), which is a representative solar wind model. As a result, we found that the entropy per

R. P. Fender, R. M. Hjellming, R. P. J. Tilanus, G. G. Pooley

We present observations of the X-ray transient XTE J1118+480 during its Low/Hard X-ray state outburst in 2000, at radio and sub-millimetre wavelengths with the VLA, Ryle Telescope, MERLIN and JCMT. The high-resolution MERLIN observations reveal all the radio emission (at 5 GHz) to come from a compact core with physical dimensions smaller than 65*d(kpc) AU. T

Denis Burgarella, Markus Kissler-Patig, Veronique Buat

We studied the metal-poor globular cluster (GC) populations of a large variety of galaxies (47 galaxies spanning about 10mag in absolute brightness) and compared their mean [Fe/H] with the properties of the host galaxies. The mean [Fe/H] of the systems lie in the -1.65<[Fe/H]<-1.20 range (74% of the population). Using only GC systems with more than 6 objects

Denis Burgarella, Veronique Buat, Jose Donas, Bruno Milliard

We used ultraviolet (200 nm) images of the local spiral galaxies M33, M51, M81, M100, M101 to compute morphological parameters of galactic disks at this wavelength : half-light radius $r_{hl}$, surface brightness distributions, asymmetries ($A$) and concentrations ($C_A$). The visibility and the evolution of the morphological parameters are studied as a func

M. Hernanz, J. Jose, A. Coc

A general review of the relevance of classical novae for the chemical evolution of the Galaxy, as well as for Galactic radioactivity is presented. A special emphasis is put on the pioneering work done by Jim Truran in this field of research. The impact of recent developments in nuclear astrophysics on nova nucleosynthesis, together with the prospects for obs

E. Cappellaro, F. Patat, P. A. Mazzali, S. Benetti

About 500d after explosion the light curve of the Type Ia SN1998bu suddenly flattened and at the same time the spectrum changed from the typical nebular emission to a blue continuum with broad absorption and emission features reminiscent of the SN spectrum at early phases. We show that in analogy to SN1991Tbu (Schmidt et al. 1994), this can be explained by t

I. Soszynski, A. Udalski, M. Szymanski, M. Kubiak

We present a sample of 76 double-mode Cepheids detected in the 4.5 square degree area in the central part of the LMC. 19 stars from the sample pulsate in the fundamental mode and the first overtone while 57 objects are the first and second overtone pulsators. We analyze the period ratio of double-mode Cepheids and Fourier parameters of decomposition of the l

C. Hirano, C. R. Gwinn

In the relativistic plasma surrounding a pulsar, a subluminal ordinary-mode electromagnetic wave will propagate along a magnetic field line. After some distance, it can break free of the field line and escape the magnetosphere to reach an observer. We describe a simple model of pulsar radio emission based on this scenario and find that applying this model to

Aparna Venkatesan, James W. Truran

At present, there are several feasible observational probes of the first stars in the universe. Here, we examine the constraints on early stellar activity from the metallicity of the high-redshift Ly-$α$ clouds, from the effects of stellar ionizing photons on reionization and the cosmic microwave background (CMB), and from the implications of gravitational m

Li-Sheng Tseng

We construct intersecting D-branes as noncommutative solitons in bosonic and type II string theory. ``Defect&#39;&#39; branes which are D-branes containing bubbles of the closed string vacuum play an important role in the construction.

Laura Mersini, Mar Bastero-Gil, Panagiota Kanti

As yet, there is no underlying fundamental theory for the transplanckian regime. There is a need to address the issue of how the observables in our present universe are affected by processes that may have occured during the transplanckian regime. A particular feature of the family of dispersion functions chosen is the production of ultralow frequencies at ve

M. E. J. Newman, R. M. Ziff

We describe in detail a new and highly efficient algorithm for studying site or bond percolation on any lattice. The algorithm can measure an observable quantity in a percolation system for all values of the site or bond occupation probability from zero to one in an amount of time which scales linearly with the size of the system. We demonstrate our algorith

S. Larochelle, A. Mehta, N. Kaneko, P. K. Mang

Synchrotron x-ray scattering measurements of the low-temperature structure of the single-layer manganese oxide La$_{1-x}$Sr$_{1+x}$MnO$_4$, over the doping range $0.33 \le x \le 0.67$, indicate the existence of three distinct regions: a disordered phase ($x < 0.4$), a charge-ordered phase ($x \ge 0.5$), and a mixed phase ($0.4 \le x < 0.5$). For $x>0.5$, the

CLAS Collaboration, K. Lukashin, E. S. Smith

We studied the exclusive reaction e p --> e&#39; p&#39; phi using the phi --> K^+ K^- decay mode. The data were collected using a 4.2 GeV incident electron beam and the CLAS detector at Jefferson Lab. Our experiment covers the range in Q^2 from 0.7 to 2.2 GeV^2, and W from 2.0 to 2.6 GeV. Taken together with all previous data, we find a consistent picture of

Jose A. Oller

The effective SU(2) chiral Lagrangian with external sources is given in the presence of non-vanishing nucleon densities by calculating the in-medium contributions of the chiral pion-nucleon Lagrangian. As a by product, a relativistic quantum field theory for Fermi many-particle systems at zero temperature is directly derived from relativistic quantum field t

Subhasis Sinha, Yvan Castin

We consider a Bose-Einstein condensate subject to a rotating harmonic potential, in connection with recent experiments leading to the formation of vortices. We use the classical hydrodynamic approximation to the non-linear Schrödinger equation to determine almost analytically the evolution of the condensate. We predict that this evolution can exhibit dynamic

A. M. Khvedelidze, D. M. Mladenov

Relations between the free motion on the GL^+(n, R) group manifold and the dynamics of an n-particle system with spin degrees of freedom on a line interacting with the pairwise 1/sinh^2 x ``potential&#39;&#39; (Euler-Calogero-Sutherland model) is discussed in the framework of Hamiltonian reduction. Two kinds of reductions of the degrees of freedom are consid

S. Bose, D. Home

A general and an arbitrarily efficient scheme for entangling the spins (or any spin-like degree of freedom) of two independent uncorrelated identical particles by a combination of two particle interferometry and which way detection is formulated. It is shown that the same setup could be used to identify the quantum statistics of the incident particles from e

B. Utter, R. Ragnarsson, E. Bodenschatz

We report experimental results on the tip splitting dynamics of seaweed growth in directional solidification of succinonitrile alloys with poly(ethylene oxide) or acetone as solutes. The seaweed or dense branching morphology was selected by solidifying grains which are oriented close to the {111} plane. Despite the random appearance of the growth, a quasiper

Takashi Hamana, Yannick Mellier

We present ray tracing simulations combined with sets of large N-body simulations. Experiments were performed to explore, for the first time, statistical properties of fluctuations in angular separations of nearby light ray pairs (the so-called lensing excursion angle) induced by weak lensing by large-scale structures. We found that the probability distribut

Wonkee Kim, J. P. Carbotte

Observed violations of the $c$-axis optical sum rule can give important information on deviations from in-plane Fermi liquid behavior and on the nature of interlayer coupling between adjacent copper oxide planes. Application of a magnetic field perpendicular to these planes is another way to probe in-plane dynamics. We find that the optical sum rule is consi

J. M. Udias, J. A. Caballero, E. Moya de Guerra, Javier R. Vignote

We use the relativistic distorted wave impulse approximation to analyze data on 16O(e,e&#39;p)15N at |Q^2|\leq 0.4 (GeV/c)^2 that were obtained by different groups and seemed controversial. Results for differential cross-sections, response functions and A_TL asymmetry are discussed and compared to different sets of experimental data for proton knockout from

P. E. Jönsson, J. L. Garcia-Palacios

Thermodynamic perturbation theory is employed to derive analytical expressions for the equilibrium linear susceptibility and specific heat of lattices of anisotropic classical spins weakly coupled by the dipole-dipole interaction. The calculation is carried out to the second order in the coupling constant over the temperature, while the single-spin anisotrop

Giampiero Esposito

Previous work in the literature has studied gravitational radiation in black-hole collisions at the speed of light. In particular, it had been proved that the perturbative field equations may all be reduced to equations in only two independent variables, by virtue of a conformal symmetry at each order in perturbation theory. The Green function for the pertur

Siming Liu, Fulvio Melia

The hypothesized supermassive black hole in the nucleus of M31 (which we shall hereafter call M31*) has many features in common with Sgr A* at the Galactic Center, yet they differ in several significant and important ways. Though M31* is probably ten times heavier, its radio luminosity at 3.6 cm is only one third that of Sgr A*. At the same time, M31* is app

Thorsten Renk

Following prior analysis for measured pp elastic differential cross section, the impact parameter representation in terms of profile functions is calculated from two different parameterizations on single diffractive dissociation data. The derivative of this quantity with respect to the collision energy squared s measures the growth rate of the reaction&#39;s

R. Valenti, T. Saha-Dasgupta, J. V. Alvarez, K. Pozgajcic

We determine the electronic structure of the one-dimensional spin-1/2 Heisenberg compound $γ$-LiV$_2$O$_5$, which has two inequivalent vanadium ions, V(1) and V(2), via density-functional calculations. We find a relative V(1)-V(2) charge ordering of roughly $70:30$. We discuss the influence of the charge ordering on the electronic structure and the magnetic

S. I. Matveenko, S. A. Brazovskii

For a one-dimensional electron-phonon system we consider the photon absorption involving electronic excitations within the pseudogap energy range. Within the adiabatic approximation for the electron - phonon interactions these processes are described by nonlinear configurations of an instanton type. We calculate intensities of the photoelectron spectroscopy

ALEPH Collaboration, DELPHI Collaboration, L3 Collaboration, OPAL Collaboration

The precise determination of the Z boson parameters from the measurements at the Z resonance by the four collaborations ALEPH, DELPHI, L3 and OPAL in e+e- collisions at the large electron positron collider LEP at CERN is a landmark for precision tests of the electroweak theory. The four experiments measured quantities which were used to extract the mass and

Tsuyoshi Kobayashi

In this paper, we show that, for each non-trivial two bridge knot K and for each g > 2, every genus g Heegaard splitting of the exterior E(K) of K is reducible.

H. Tanaka, A. Oosawa, T. Kato, H. Uekusa

Neutron elastic scattering experiments have been performed on the spin gap system TlCuCl$_3$ in magnetic fields parallel to the $b$-axis. The magnetic Bragg peaks which indicate the field-induced Néel ordering were observed for magnetic field higher than the gap field $H_{\rm g}\approx 5.5$ T at $Q=(h, 0, l)$ with odd $l$ in the $a^*-c^*$ plane. The spin str

Maxim Olshanii, Ludovic Pricoupenko

We have found an expression for the full many-body Green&#39;s function of N pairwise finite-range interacting atoms, in a form of a chain fraction involving two-body T-matrices only, with no explicit presence of the interaction potentials themselves. We show that in the limit of infinitely small potential range, this expression reduces to the Green&#39;s fu

C. Raghu, Indranil Rudra, Diptiman Sen, S. Ramasesha

Using an efficient numerical scheme that exploits spatial symmetries and spin parity, we have obtained the exact low-lying eigenstates of exchange Hamiltonians for the high nuclearity spin clusters, Mn_{12}, Fe_8 and V_{15}. The largest calculation involves the Mn_{12} cluster which spans a Fock space of a hundred million. Our results show that the earlier e

Chuan-Hung Chen, C. Q. Geng

We study the dilepton forward-backward and the longitudinal, normal and transverse lepton polarization asymmetries in the heavy baryon decays of $Λ_b\toΛl^+l^-$. We show that the asymmetries have a less dependence on the non-perturbative QCD effects. In the standard model, we find that the integrated forward-backward asymmetries (FBAs) and three components o

Soebur Razzaque, Surujhdeo Seunarine, David Z. Besson, Douglas W. McKay

We investigate the development of electromagnetic cascades in ice using a GEANT Monte Carlo simulation. We examine the Cherenkov pulse that is generated by the charge excess that develops and propagates with the shower. This study is important for the RICE experiment at the South Pole, as well as any test beam experiment which seeks to measure coherent Chere

Takayuki Tomaru, Takashi Uchiyama, Daisuke Tatsumi, Shinji Miyoki

We have applied laser calorimetry to the measurement of optical absorption in mono-crystalline sapphire at cryogenic temperatures. Sapphire is a promising candidate for the mirror substrates of the Large-scale Cryogenic Gravitational wave Telescope. The optical absorption coefficients of different sapphire samples at a wavelength of 1.064(micro)m at 5K were

Carl M. Bender, Gerald V. Dunne, Peter N. Meisinger, Mehmet Simsek

Quantum-mechanical PT-symmetric theories associated with complex cubic potentials such as V=x^2+y^2+igxy^2 and V=x^2+y^2+z^2+igxyz, where g is a real parameter, are investigated. These theories appear to possess real, positive spectra. Low-lying energy levels are calculated to very high order in perturbation theory. The large-order behavior of the perturbati

Louis Sica

Assumed data streams from a delayed choice gedanken experiment must satisfy a Bell&#39;s identity independently of locality assumptions. The violation of Bell&#39;s inequality by assumed correlations of identical form among these data streams implies that they cannot all result from statistically equivalent variables of a homogeneous process. This is consist

Michael G. A. Crawford

Klauder&#39;s recent generalization of the harmonic oscillator coherent states [J. Phys. A 29, L293 (1996)] is applicable only in non-degenerate systems, requiring some additional structure if applied to systems with degeneracies. The author suggests how this structure could be added, and applies the complete method to the hydrogen atom problem. To illustrat

W. A. Hofer

The quest for a complete theory of microphysics is probably near the top of the agenda in fundamental physics today. We survey existing modifications of quantum mechanics to assess their potential. In the following we present recent results in microdynamics, focussing on dynamic charge. The theoretical model, valid at all length scales, relates mass oscillat

Lorenza Viola, Emanuel Knill, Raymond Laflamme

The notion of a qubit is ubiquitous in quantum information processing. In spite of the simple abstract definition of qubits as two-state quantum systems, identifying qubits in physical systems is often unexpectedly difficult. There are an astonishing variety of ways in which qubits can emerge from devices. What essential features are required for an implemen

Uffe V. Poulsen, Klaus Molmer

The collisional interaction in a Bose condensate represents a non-linearity which in analogy with non-linear optics gives rise to unique quantum features. In this paper we apply a Monte Carlo method based on the positive P pseudo-probability distribution from quantum optics to analyze the efficiency of spin squeezing by collisions in a two-component condensa

Shahar Dolev, Avshalom C. Elitzur, Meir Hemmo

In any physical theory that admits true indeterminism, the thermodynamic arrow of time can arise regardless of the system&#39;s initial conditions. Hence on such theories time&#39;s arrow emerges out of the basic physical interactions. The example of the GRW theory is studied in detail.

Louis Sica

Derivations of two Bell&#39;s inequalities are given in a form appropriate to the interpretation of experimental data for explicit determination of all the correlations. They are arithmetic identities independent of statistical reasoning and thus cannot be violated by data that meets the conditions for their validity. Two experimentally performable procedure

A. V. Chizhov, E. Schmidt, L. Knoll, D. -G. Welsch

The modification of initially entangled light pulses passing through dispersive and absorbing four-port devices is studied, using recently obtained results on quantum state transformations [Phys. Rev. A 59, 4716 (1999)]. The fidelity and indices of quantum correlations based on the von Neumann entropy are calculated. Their dependence on both the pulse shape

P. Akritas, I. Antoniou, E. Yarevsky

We assess Coarse Graining by studying different partitions of the phase space of the Baker transformation and the periodic torus automorphisms. It turns out that the shape of autocorrelation functions for the Baker transformation is more or less reproduced. However, for certain partitions the decay rates turn out to be irrelevant, even decay may stop in a fi

B. G. Sidharth

We argue that there was a link between Indus Valley India and the Mayans of Central America which is brought out by astronomical references. The former used a Jovian calendar while the latter had perfected a calendar based on Venus. This will be shown to be a significant clue. This also provides an explanation for the as yet unexplained fact that the Indus s

K. Langanke, G. Martinez-Pinedo, J. M. Sampaio

Using the recent shell model evaluation of stellar weak interaction rates we have calculated the neutrino spectra arising from electron capture on pf-shell nuclei under presupernova conditions. We present a simple parametrization of the spectra which allows for an easy implementation into collapse simulations. We discuss that the explicit consideration of th

Gargi Chaudhuri, Santanu Pal

Fission dynamics of excited nuclei is studied in the framework of Langevin equation. The one body wall-and-window friction is used as the dissipative force in the Langevin equation. In addition to the usual wall formula friction, the chaos weighted wall formula developed earlier to account for nonintegrability of single-particle motion within the nuclear vol

David A. Kessler, Herbert Levine

We study the issue of the selection of viscous fingering patterns in the limit of small surface tension. Through detailed simulations of anisotropic fingering, we demonstrate conclusively that no selection independent of the small-scale cutoff (macroscopic selection) occurs in this system. Rather, the small-scale cutoff completely controls the pattern, even

Metin Gurses, Atalay Karasu, Refik Turhan

Non-autonomous Svinolupov-Jordan systems are considered. The integrability criteria of such systems are associated with the existence of recursion operators. A new non-autonomous KdV system is obtained and its recursion operator is given for all $N$. The examples for N=2 and N=3 are studied in detail. Some possible transformations are also discussed which ma

Peter A. Markowich, Gerhard Rein, Gershon Wolansky

We consider the Schrödinger-Poisson system in the attractive (plasma physics) Coulomb case. Given a steady state from a certain class we prove its nonlinear stability, using an appropriately defined energy-Casimir functional as Lyapunov function. To obtain such steady states we start with a given Casimir functional and construct a new functional which is in

Victor Guillemin, Lisa Jeffrey, Reyer Sjamaar

Let $K$ be a compact Lie group. We introduce the process of symplectic implosion, which associates to every Hamiltonian $K$-manifold a stratified space called the imploded cross-section. It bears a resemblance to symplectic reduction, but instead of quotienting by the entire group, it cuts the symmetries down to a maximal torus of $K$. We examine the nature

N. Christopher Phillips

We prove the following results for a unital simple direct limit $A$ of recursive subhomogeneous algebras with no dimension growth: (1) A has stable rank 1. (2) The projections in $M_{\infty} (A)$ satisfy cancellation: if $e \oplus q \sim f \oplus q$, then $e \sim f$. (3) $A$ satisfies Blackadar&#39;s Second Fundamental Comparability Question: if $p, q \in M_

N. Christopher Phillips

We introduce and characterize a particularly tractable class of unital type 1 C*-algebras with bounded dimension of irreducible representations. Algebras in this class are called recursive subhomogeneous algebras, and they have an inductive description (through iterated pullbacks) which allows one to carry over from algebras of the form C (X, M_n) many of th

Liviu I. Nicolaescu

We construct several natural connections and Dirac type operators on a general metric contact manifold which are more sensitive to the geometric background. In the special case of CR manifolds these connections are also compatible with the CR structure and include among them the Webster connection. We also describe several Weitzenbock type formulae. Our meth

Marco Grandis

It is known that factorisation systems in categories can be viewed as unitary pseudo algebras for the &#34;squaring&#34; monad in Cat. We show in this note that an analogous fact holds for proper (i.e., epi-mono) factorisation systems and a suitable quotient of the former monad, deriving from a construct introduced by P. Freyd for stable homotopy. Structural

Grigori Litvinov, Viktor Maslov, Grigori Shpiz

We study idempotent analogs of topological tensor products in the sense of A. Grothendieck. The basic concepts and results are simulated on the algebraic level. This is one of a series of papers on idempotent functional analysis.

Grigori Litvinov, Anatoli Rodionov, Andrei Chourkin

We describe an approximate rational arithmetic with round-off errors (both absolute and relative) controlled by the user. The rounding procedure is based on the continued fraction expansion of real numbers. Results of computer experiments are given in order to compare efficiency and accuracy of different types of approximate arithmetics and rounding procedur

J. I. Brand, M. S. Hallbeck, S. M. Ryan

Multi-dimensional meta-analysis (MDMA) is an innovative technique for investigating complex scientific problems influenced by &#34;external&#34; factors, such as social, medical, economic, political or climatic trends. MDMA extends traditional meta-analysis by identifying significant data from diverse and independent disciplines (&#34;orthogonal dimensions&#

Ruslan Sharipov

Formula for the force field of Newtonian dynamical systems admitting the normal shift of hypersurfaces in Riemannian manifolds is considered. Problem of globalization for geometric structures associated with this formula is studied.

Stefano Marmi, David Sauzin

We prove that the solutions of a cohomological equation of complex dimension one and in the analytic category have a monogenic dependence on the parameter, and we investigate the question of their quasianalyticity. This equation is the standard linearized conjugacy equation for germs of holomorphic maps in a neighborhood of a fixed point. The parameter is th

David B. Massey

If a complex analytic function, $f$, has a stratified isolated critical point, then it is known that the cohomology of the Milnor fibre of $f$ has a direct sum decomposition in terms of the normal Morse data to the strata. We use microlocal Morse theory to obtain the same result under the weakened hypothesis that the vanishing cycles along $f$ have isolated

E. Deotto, E. Gozzi, D. Mauro

We briefly review the universal supersymmetry present in classical hamiltonian systems and show its applications to field theories.

S. Ferrara

Superconformal algebras embedding space-time in any dimension and signature are considered. Different real forms of the $R$-symmetries arise both for usual space-time signature (one time) and for Euclidean or exotic signatures (more than one times). Application of these superalgebras are found in the context of supergravities with 32 supersymmetries, in any

N. A. Obers, B. Pioline

In this lecture we summarize some recent work on the understanding of instanton effects in string theories with 16 supersymmetries. In particular, we consider F^4 couplings using the duality between the heterotic string on T^4 and type IIA on K_3 at an orbifold point, as well as higher and lower dimensional versions of this string-string duality. At the pert

A. R. Bohm, R. de la Madrid, B. A. Tay, P. Kielanowski

The definition of mass and width of relativistic resonances and in particular of the $Z$-boson is discussed. For this we use the theory based on time asymmetric boundary conditions given by Hardy class spaces ${\mathbf Φ}_-$ and ${\mathbf Φ}_+$ for prepared in-states and detected out-states respectively, rather than time symmetric Hilbert space theory. This

Evgeny Likhtman

This is the talk given at the Symposium &#34;Thirty Years of Supersymmetry&#34;, October 13-15, 2000, Theoretical Physics Institute, University of Minnesota. The history of construction of the first supersymmetric field theory in four dimensions (1970) is reviewed. In Appendix a verbatim translation of my paper published in 1971 in Russian (preprint FIAN-41)

Ilya F. Ginzburg, Maria Krawczyk, Per Osland

We consider the possibility that after operations at the LHC and e^+e^- Linear Colliders a Higgs boson will be discovered, but no signal of New Physics will be found (Standard-Model-like scenario). This can occur in the Standard Model (SM) as well as in other models, including the Two-Higgs-Doublet Model (2HDM), the MSSM, etc. Experiments at a Photon Collide