September 2003 arXiv papers — page 9

PACS Collaboration, T. Yamazaki, S. Aoki, M. Fukugita

We present a calculation of the scattering phase shift for the I=2 S-wave pion-pion system in the continuum limit with two-flavor full QCD. Calculations are made at three lattice spacings, using the finite volume method of Lüscher in the center of mass frame, and its extension to the laboratory frame.

T. P. Shestakova

In the context of the recently proposed formulation of quantum geometrodynamics in extended phase space we discuss the problem how the behavior of the Universe, initially managed by quantum laws, has become classical. In this version of quantum geometrodynamics we quantize gauge gravitational degrees of freedom on an equal basis with physical degrees of free

A. Herrero, M. Portilla

We analyze the effect of pressure on the evolution of perturbations of an Einstein-de Sitter Universe in the matter dominated epoch assuming an ideal gas equation of state. For the sake of simplicity the temperature is considered uniform. The goal of the paper is to examine the validity of the linear approximation. With this purpose the evolution equations a

Andreas Zeller

Debugging is commonly understood as finding and fixing the cause of a problem. But what does ``cause'' mean? How can we find causes? How can we prove that a cause is a cause--or even ``the'' cause? This paper defines common terms in debugging, highlights the principal techniques, their capabilities and limitations.

K. Vezerides, Ath. Kehagias

We study self-referential sentences of the type related to the Liar paradox. In particular, we consider the problem of assigning consistent fuzzy truth values to collections of self-referential sentences. We show that the problem can be reduced to the solution of a system of nonlinear equations. Furthermore, we prove that, under mild conditions, such a syste

Agostino Dovier, Carla Piazza, Gianfranco Rossi

Lists, multisets, and sets are well-known data structures whose usefulness is widely recognized in various areas of Computer Science. These data structures have been analyzed from an axiomatic point of view with a parametric approach in (*) where the relevant unification algorithms have been developed. In this paper we extend these results considering more g

C. Escudero, J. Buceta, F. J. de la Rubia, Katja Lindenberg

We study a generic reaction-diffusion model for single-species population dynamics that includes reproduction, death, and competition. The population is assumed to be confined in a refuge beyond which conditions are so harsh that they lead to certain extinction. Standard continuum mean field models in one dimension yield a critical refuge length L_c such tha

E. H. Martins Ferreira, M. C. Nemes, M. D. Sampaio, H. Weidenmueller

We investigate the influence of the topology on generic features of the persistent current in n-fold twisted Moebius strips formed of quasi one--dimensional mesoscopic rings, both for free electrons and in the weakly disordered regime. We find that there is no generic difference between the persistent current for untwisted rings and for Moebius strips with a

C. F. Hirjibehedin, Irene Dujovne, A. Pinczuk, B. S. Dennis

Low lying excitations of electron liquids in the fractional quantum Hall (FQH) regime are studied by resonant inelastic light scattering methods. We present here results from charge and spin excitations of FQH states in the lowest spin-split Landau levels that are of current interest. In the range of filling factors $2/5 \geq ν\geq 1/3$, we find evidence tha

Jürgen Walter, Itsuko S. Suzuki, Masatsugu Suzuki

A complex carbide Ta$_{2}$S$_{2}$C consists of van der Waals (vdw)-bonded layers with a stacking sequence $...$ C-Ta-S-vdw-S-Ta-C- $...$ along the c axis. The magnetic properties of this compound have been studied from DC and AC magnetic susceptibility. Ta$_{2}$S$_{2}$C undergoes successive superconducting transitions of a hierachical nature at $T_{cl} = 3.6

David R. Nelson

The denaturation of double-stranded DNA as function of force and temperature is discussed. At room temperature, sequence heterogeneity dominates the physics of single molecule force-extension curves starting about 7 piconewtons of below a ~15 pN unzipping transition. The dynamics of the unzipping fork exhibits anomalous drift and diffusion in a similar range

A. V. Kats, Y. V. Bludov

The paper deals with the theoretical investigation of plane, normally incident electromagnetic wave transmission through the flat metal film whose dielectric constant has small periodical sinusoidal modulation in one dimension parallel to the projection of the electric field onto the film surface. The dependencies of the film transmittancy on the parameters

S. T. Chui, Z. F. Lin

We show that when the magnetizations on opposite sides of a junction are not collinear, the magnetization current is not conserved as the junction is crossed. Thus the usual treatment of this problem needs to be modified. We argue that this is due to an implicit assumption of an external torque that is required to clamp the magnetization in place. The physic

Gleb Basalyga, Magnus Rattray

The learning dynamics of on-line independent component analysis is analysed in the limit of large data dimension. We study a simple Hebbian learning algorithm that can be used to separate out a small number of non-Gaussian components from a high-dimensional data set. The de-mixing matrix parameters are confined to a Stiefel manifold of tall, orthogonal matri

P. Monthoux, G. G. Lonzarich

We conpare predictions of the mean-field theory of supercnductivity for metallic systems on the border of a density instability for cubic and tetragonal lattices. The calculations are based on a parametrisation of an effective interaction arising from the exchange of density fluctuations and assume that a single band is relevant for superconductivity. The re

R. R. Fulco, B. C. S. Grandi

We studied in this work a modified version of the Ziff, Gulari and Barshad (ZGB) model in which the adsorption probabilities of CO and O2 are site dependent. We employed Monte Carlo simulations to determine the phase diagram of the model as a function of the partial pressure of CO in the gaseous phase, and of the relative adsorption probabilities. For the ca

R. Donangelo, K. Sneppen

We consider in a market model the cooperative emergence of value due to a positive feedback between perception of needs and demand. Here we consider also a negative feedback from production of the traded products, and find that this cooperativity is robust, provided that the production rate is slow. Cooperativity is found to be critically linked to the abili

Oleg Yevtushenko, Vladimir E. Kravtsov

We study the density of states (DOS) for disordered systems whose spectral statistics can be described by a Gaussian ensemble of almost diagonal Hermitian random matrices. The matrices have independent random entries $ H_{i \geq j} $ with small off-diagonal elements: $ <|H_{i \neq j}|^{2} > \ll <|H_{ii}|^{2} > \sim 1 $. Using the recently suggested method of

C. Timm, F. von Oppen, F. Höfling

The carrier spin and impurity spin densities in diluted magnetic semiconductors are considered using a semiclassical approach. Equations of motions for the spin densities and the carrier spin current density in the paramagnetic phase are derived, exhibiting their coupled diffusive dynamics. The dynamical spin susceptibilities are obtained from these equation

R. S. Gonnelli, D. Daghero, A. Calzolari, G. A. Ummarino

In this paper we highlight the advantages of using point-contact spectroscopy (PCS) in multigap superconductors like MgB_2, both as a fundamental research tool and as a non-destructive diagnostic technique for the optimization of thin-film characteristics. We first present some results of crucial fundamental interest obtained by directional PCS in MgB_2 sing

M. Llas, P. M. Gleiser, J. M. Lopez, A. Diaz-Guilera

We characterize the different morphological phases that occur in a simple one-dimensional model of propagation of innovations among economic agents [X.\ Guardiola, {\it et. al.}, Phys. Rev E {\bf 66}, 026121 (2002)]. We show that the model can be regarded as a nonequilibrium surface growth model. This allows us to demonstrate the presence of a continuous rou

V. Ferrando, C. Tarantini, P. Manfrinetti, D. Marre&#39;

In this paper, we analyze the upper critical field of four MgB2 thin films, with different resistivity (between 5 to 50 mWcm) and critical temperature (between 29.5 to 38.8 K), measured up to 28 Tesla. In the perpendicular direction the critical fields vary from 13 to 24 T and we can estimate 42-57 T range in other direction. We observe linear temperature de

A. I. Krivchikov, B. Ya. Gorodilov, V. G. Manzhelii, V. V. Dudkin

The dynamic interaction of a quantum rotor with its crystalline environment has been studied by measurement of the thermal conductivity of solid Kr1_c(CH4)_c solutions at c = 0.05-0.75 in the temperature region from 2 up to 40K. The thermal resistance of the solutions was mainly determined by the resonance scattering of phonons by CH4 molecules with the nucl

V. A. Konstantinov, O. I. Purskii, N. N. Zholonko

The thermal conductivity of solid SF6, CHCI3, C6H6, and CCl4 was investigated by the linear-flow method under saturated vapor pressures in the temperature range from 80 K to the corresponding melting temperatures and then recalculated for a constant density of the samples.The contributions of the phonon -phonon and phonon -rotation interactions to the total

P. Samuelsson, E. Sukhorukov, M. Buttiker

We discuss orbital entanglement in mesoscopic conductors, focusing on the effect of dephasing. The entanglement is detected via violation of a Bell Inequality formulated in terms of zero-frequency current correlations. Following closely the recent work by Samuelsson, Sukhorukov and Buttiker, we investigate how the dephasing affects the possibility to violate

Kenichi Kasamatsu, Makoto Tsubota, Masahito Ueda

We theoretically investigate quadrupolar collective excitations in two-component Bose-Einstein condensates and their nonlinear dynamics associated with harmonic generation and mode coupling. Under the Thomas-Fermi approximation and the quadratic polynomial ansatz for density fluctuations, the linear analysis of the superfluid hydrodynamic equations predicts

A. Kormányos, Z. Kaufmann, C. J. Lambert, J. Cserti

An effective random matrix theory description is developed for the universal gap fluctuations and the ensemble averaged density of states of chaotic Andreev billiards for finite Ehrenfest time. It yields a very good agreement with the numerical calculation for Sinai-Andreev billiards. A systematic linear decrease of the mean field gap with increasing Ehrenfe

E. P. De Poortere, E. Tutuc, M. Shayegan

Magnetic transitions in AlAs two-dimensional electrons give rise to sharp resistance spikes within the quantum Hall effect. Such spikes are likely caused by carrier scattering at magnetic domain walls below the Curie temperature. We report a critical behavior in the temperature dependence of the spike width and amplitude, from which we deduce the Curie tempe

Igor Goychuk, Peter Hanggi

The phenomenological linear response theory of non-Markovian Stochastic Resonance (SR) is put forward for stationary two-state renewal processes. In terms of a derivation of a non-Markov regression theorem we evaluate the characteristic SR-quantifiers; i.e. the spectral power amplification (SPA) and the signal-to-noise ratio (SNR), respectively. In clear con

S. Mieske, M. Hilker

We present I-band Surface Brightness Fluctuations (SBF) measurements for 15 early type galaxies (3 giants, 12 dwarfs) in the central region of the Centaurus cluster, based on VLT FORS1 imaging data. From the SBF-distances to our sample galaxies we determine the distance of the Centaurus cluster to be 41.3 +/- 2.1 Mpc (33.08 +/- 0.11 mag), about the same dist

Inseok Song, B. Zuckerman, M. S. Bessell

We have identified three faint new members of the eta Chamaeleontis cluster. Spectral types of the new members are estimated to be ~M5 based on their TiO band strengths and broadband colors. With an age of 5-8 Myr for the cluster, masses of these new members are estimated to be ~0.08 Msun. All three display strong Li 6708A absorption and Halpha emission feat

Joel H. Kastner, Noam Soker

Recent observations of the Egg Nebula (AFGL 2688), obtained at ever-increasing spatial and spectral resolution, have revealed a perplexing array of phenomena. Many of these phenomena present challenges to our understanding of this object as an emerging, bipolar planetary nebula. Here, we consider two particularly intriguing aspects of the Egg: the peculiar s

Steven R. Cranmer

This paper reviews the latest observational evidence for the existence of propagating waves in the open magnetic flux tubes of the solar corona. SOHO measurements have put tentative limits on the fluxes of various types of magnetohydrodynamic (MHD) waves in the acceleration region of the solar wind. Also, continually improving measurements of fluctuations at

Jaron Kurk, Bram Venemans, Huub Rottgering, George Miley

We have carried out narrow band imaging targeted at the Lya line of emitters associated with radio galaxies at 2 < z < 5. Subsequent spectroscopy has confirmed the identity of > 120 Lya emitters and led to the discovery of six proto-clusters up to z = 4.1 with velocity dispersions between 300 and 1000 km/s. The number of emission line galaxies in the observe

Adolf N. Witt, Uma P. Vijh

Interstellar dust in nebulae and in the diffuse interstellar medium of galaxies contains a component which responds to illumination by ultraviolet photons with efficient luminescence in the 500 nm to 1000 nm spectral range, known as Extended Red Emission (ERE). We review the techniques of detection and the observational characteristics of the ERE in a wide r

Jason Pruet, Rebecca Surman, Gail C. McLaughlin

Light curves from a growing number of Gamma Ray Bursts (GRBs) indicate that GRBs copiously produce radioactive Ni moving outward at fractions of the speed of light. We calculate nuclear abundances of elements accompanying the outflowing Ni under the assumption that this Ni originates from a wind blown off of a viscous accretion disk. We also show that GRB&#3

Andre Maeder, Georges Meynet

We compare the current effects of rotation in stellar evolution to those of the magnetic field created by the Tayler instability. In stellar regions, where magnetic field can be generated by the dynamo due to differential rotation (Spruit 2002), we find that the growth rate of the magnetic instability is much faster than for the thermal instability. Thus, me

F. Canfora, A. Troisi

Astrophysical observations provide a picture of the universe as a 4-dim homogeneous and isotropic flat space-time dominated by an unknown form of dark energy. To achieve such a cosmology one has to consider in the early universe an inflationary era able to overcome problems of standard cosmological models. Here an inhomogeneous model is proposed which allows

N. Iro, B. Bezard, T. Guillot

We developed a time-dependent radiative model for the atmosphere of HD209458b to investigate its thermal structure and chemical composition. Time-dependent temperature profiles were calculated, using a uniform zonal wind modelled as a solid body rotation. We predict day/night temperature variations of 600K around 0.1 bar, for a 1 km/s wind velocity, in good

Denise C. Gabuzda, Eamonn Murray

Evidence is mounting that many of the transverse jet B fields observed in BL Lac objects on parsec scales represent the dominant toroidal component of the intrinsic jet B fields. If this is the case, this may give rise to rotation-measure (RM) gradients across the jets, due to the systematic change in the line-of-sight component of the jet B field. We have f

Vladimir Priklonsky, Anvar Shukurov, Dmitry Sokoloff, Andrew Soward

We reconsider thin-disc global asymptotics for kinematic, axisymmetric mean-field dynamos with vacuum boundary conditions. Non-local terms arising from a small but finite radial field component at the disc surface are consistently taken into account for quadrupole modes. As in earlier approaches, the solution splits into a local part describing the field dis

I. Berentzen, E. Athanassoula, C. H. Heller, K. J. Fricke

We study the regeneration of stellar bars triggered by a tidal interaction, using numerical simulations of either purely stellar or stellar+gas disc galaxies. We find that interactions which are sufficiently strong to regenerate the bar in the purely stellar models do not lead to a regeneration in the dissipative models, owing to the induced gas inflow in th

S. Martin, R. Mauersberger, J. Martin-Pintado, S. Garcia-Burillo

We report the first detections of SO_2, NS and NO in an extragalactic source, the nucleus of the starburst galaxy NGC 253. Five SO_2 transitions, three groups of hyperfine components of NO and five of NS were detected. All three species show large abundances averaged over the inner 200 pc of NGC 253. With a relative abundance of a few 10^-7, the emission of

Prasad Subramanian, S. Ananthakrishnan, P. Janardhan, M. R. Kundu

We present the first observations of a solar flare with the GMRT. An M2.8 flare observed at 1060 MHz with the GMRT on Nov 17 2001 was associated with a prominence eruption observed at 17 GHz by the Nobeyama radioheliograph and the initiation of a fast partial halo CME observed with the LASCO C2 coronograph. Towards the start of the eruption, we find evidence

M. Hanasz, H. Lesch

We present a numerical algorithm for the incorporation of the active cosmic ray transport, into the ZEUS-3D magnetohydrodynamical code. The cosmic ray transport is described by the diffusion-advection equation. The applied form of the diffusion tensor allows for anisotropic diffusion of cosmic rays along and across the magnetic field direction, which is cont

Yanbin Yang, Xu Zhou, Qirong Yuan, Zhaoji Jiang

This paper presents a multicolor study of the nearby cluster of galaxies Abell 168 (z=0.045) with 13 intermediate-band filters in the Beijing-Arizona-Taiwan-Connecticut (BATC) filter system. After a cross-identification between the photometric data obtained from the BATC and the Sloan Digital Sky Survey (SDSS), a catalog containing 1553 galaxies down to r&#3

Chengmin Zhang

The magnetic field strengths of most millisecond pulsars(MSP) are about $10^{8-9}$ Gauss. The accretion induced magnetic field evolution scenario here concludes that the field decay is invesely related to the accreted mass and the minimum field or bottom field stops at about $10^{8}$ Gauss if accreted with the Eddington accretion rate, which is proportionall

C. Boehm, H. Mathis, J. Devriendt, J. Silk

Dark Matter (DM) is generally assumed to be massive, cold and collisionless from the structure formation point of view. A more correct statement however is that DM indeed experiences collisional damping, but on a scale which is supposed to be too small to be relevant for structure formation. The aim of this paper is to present a Cold (although ``collisional&

L. C. Stonehill, J. A. Formaggio, R. G. H. Robertson

The neutrino flux from the sun is predicted to have a CNO-cycle contribution as well as the known pp-chain component. Previously, only the fluxes from beta+ decays of 13N, 15O, and 17F have been calculated in detail. Another neutrino component that has not been widely considered is electron capture on these nuclei. We calculate the number of interactions in

E. M. Darwish

Incoherent photoproduction of pions on the deuteron in the first resonance region is investigated with special emphasis on single-spin asymmetries. For the elementary pion production operator an effective Lagrangian model which includes the standard pseudovector Born terms and a resonance contribution from the $Δ$(1232)-excitation is used. Single-spin asymme

Mihalis Dafermos, Igor Rodnianski

A well-known open problem in general relativity, dating back to 1972, has been to prove Price&#39;s law for an appropriate model of gravitational collapse. This law postulates inverse-power decay rates for the gravitational radiation flux on the event horizon and null infinity with respect to appropriately normalized advanced and retarded time coordinates. I

J. C. Lagarias, N. J. A. Sloane

We study the ``approximate squaring&#39;&#39; map f(x) := x ceiling(x) and its behavior when iterated. We conjecture that if f is repeatedly applied to a rational number r = l/d > 1 then eventually an integer will be reached. We prove this when d=2, and provide evidence that it is true in general by giving an upper bound on the density of the ``exceptional s

Lloyd Knox, Gil Holder, Sarah Church

Observations of clusters in the 30 to 350 GHz range can in principle be used to determine a galaxy cluster&#39;s Comptonization parameter, y, peculiar velocity, v and gas temperature, T_e via the dependence of the kinetic and thermal Sunyaev-Zeldovich (SZ) effects on these parameters. Despite the significant contamination expected from thermal emission by du

Misty C. Bentz, Patrick S. Osmer, David H. Weinberg

{Abridged} We report the discovery of six compact, starburst galaxy candidates with redshifts 2.3 < z < 2.8 and r-band magnitudes 19.8-20.5 in the Quasar Catalog of the Sloan Digital Sky Survey First Data Release (SDSS DR1). The SDSS spectra of these objects resemble the composite spectrum of Lyman Break Galaxies (LBGs) at z ~ 3 (albeit with some differences

Jack F. Gallimore, Robert Beswick

NGC 6240 is a luminous infrared galaxy that, based on recent MERLIN and CHANDRA observations, appears to host a pair of active galactic nuclei. We present new, multiepoch and multifrequency radio observations of NGC 6240 obtained using the Very Long Baseline Array (VLBA). These observations resolve out all of the diffuse radio continuum emission related to s

Jose Gaite, Maria Paz Zorzano

The process of downfall of initially homogeneous gas onto a solid ball due to the ball&#39;s gravity (relevant in astrophysical situations) is studied with a combination of analytic and numerical methods. The initial explicit solution soon becomes discontinuous and gives rise to a shock wave. Afterwards, there is a crossover between two intermediate asymptot

C. L. Gerardy, P. Hoeflich, R. A. Fesen, G. H. Marion

We present observations of the Type Ia supernova 2003du and report the detectionof an unusual, high-velocity component in the Ca II infrared triplet, similar tofeatures previously observed in SN 2000cx and SN 2001el. This feature exhibits a large expansion velocity (~18,000 km/s) which is nearly constant between -7 and +2 days relative to maximum light, and

Hy Trac, Ue-Li Pen

We present a new approach to Eulerian computational fluid dynamics that is designed to work at high Mach numbers encountered in astrophysical hydrodynamic simulations. The Eulerian fluid conservation equations are solved in an adaptive frame moving with the fluid where Mach numbers are minimized. The moving frame approach uses a velocity decomposition techni

M. Davidse, M. de Vroome, U. Theis, S. Vandoren

We expand our previous analysis on fivebrane and membrane instanton solutions in the universal hypermultiplet, including near-extremal multi-centered solutions and mixed fivebrane-membrane charged instantons. The results are most conveniently described in terms of a double-tensor multiplet.

A. Letoublon, V. Favre-Nicolin, H. Renevier, M. G. Proietti

We have used x-ray anomalous diffraction to extract the x-ray structure factor of InAs quantum stick-like islands, embedded in InP. The average height of the quantum sticks (QSs), as deduced from the width of the structure factor profile is 2.54nm. The InAs out of plane deformation, relative to InP, is equal to 6.1%. Diffraction Anomalous Fine Structure prov

Donald Marolf, Rafael Sorkin

It has been proposed that the entropy of any object must satisfy fundamental (holographic or Bekenstein) bounds set by the object&#39;s size and perhaps its energy. However, most discussions of these bounds have ignored the possibility that objects violating the putative bounds could themselves become important components of Hawking radiation. We show that t

G. A. Jorge, R. Stern, M. Jaime, N. Harrison

We report measurements of the specific heat of the quantum spin liquid system SrCu2(BO3)2 in continuous magnetic fields H of up to 33 T. The specific heat vs temperature at zero field shows an anomaly at 8 K, marking the opening of a gap in the spin singlet excitations. At fields H~12 T, we clearly see a second anomaly that shifts to lower temperatures as H

Noam Soker, Elizabeth L. Blanton, Craig L. Sarazin

We study the possibility that a large fraction of the gas at temperatures of \~10^7 K in cooling flow clusters cools by heat conduction to lower temperatures, rather than by radiative cooling. We argue that this process, when incorporated into the so-called "moderate cooling flow model", where the effective age of the intracluster medium is much lower than t

A. De Martino, M. Marsili, I. Pérez Castillo

We study the competitive equilibrium of large random economies with linear activities using methods of statistical mechanics. We focus on economies with $C$ commodities, $N$ firms, each running a randomly drawn linear technology, and one consumer. We derive, in the limit $N,C\to\infty$ with $n=N/C$ fixed, a complete description of the statistical properties

Craig Alan Feinstein

In this note, we give a simple proof that the Riemann Hypothesis is unprovable in any reasonable axiom system.

Th. Elsaesser, B. Nagorny, A. Hemmerich

We study the collective motion of atoms confined in an optical lattice operating inside a high finesse ring cavity. A simplified theoretical model for the dynamics of the system is developed upon the assumption of adiabaticity of the atomic motion. We show that in a regime where the light shift per photon times the number of atoms exceeds the line width of t

Andrew Cumming

I review our theoretical understanding of thermonuclear flashes on accreting neutron stars, concentrating on comparisons to observations. Sequences of regular Type I X-ray bursts from GS 1826-24 and 4U 1820-30 are very well described by the theory. I discuss recent work which attempts to use the observed burst properties in these sources to constrain the com

Gorazd Cvetic

It had been known that the Borel transforms of the twice quark pole mass 2*mq and of the QCD q-barq static potential V(r) have leading infrared renormalons at b=1/2 such that they cancel in the sum. The renormalon residue of 2*mq had been determined with reasonably high precision from the known perturbative coefficients of the ratio mq/(bar mq), where (bar m

Anton Arnold, Christof Sparber

We consider a class of evolution equations in Lindblad form, which model the dynamics of dissipative quantum mechanical systems with mean-field interaction. Particularly, this class includes the so-called Quantum Fokker-Planck-Poisson model. The existence and uniqueness of global-in-time, mass preserving solutions is proved, thus establishing the existence o

Martina Knoop, Caroline Champenois, Gaëtan Hagel, Marie Houssin

The lifetime of the 3d^2D_5/2-level in singly-ionized calcium has been measured by the electron-shelving technique on different samples of rf trapped ions. The metastable state has been directly populated by exciting the dipole-forbidden 4S_1/2 - 3D_5/2 transition. In ion clouds, the natural lifetime of this metastable level has been measured to be (1095+-27

Vitor Cardoso, Jose&#39; P. S. Lemos, Shijun Yoshida

We make a thorough investigation of the asymptotic quasinormal modes of the four and five-dimensional Schwarzschild black hole for scalar, electromagnetic and gravitational perturbations. Our numerical results give full support to all the analytical predictions by Motl and Neitzke, for the leading term. We also compute the first order corrections analyticall

Anne M. Green, Stefan Hofmann, Dominik J. Schwarz

The formation of large scale structure is independent of the nature of the cold dark matter (CDM), however the fate of very small scale inhomogeneities depends on the micro-physics of the CDM particles. We investigate the matter power spectrum for scales that enter the Hubble radius well before matter-radiation equality, and follow its evolution until the ti

V. A. Abramovsky, A. V. Dmitriev

The CKMT model describing the nucleon structure function $F_2(x,Q^2)$ in the framework of conventional Regge theory with smooth soft-hard pomeron is modified. Smooth soft-hard non-vacuum reggeon dependence on incoming photon virtuality $Q^2$ is introduced. This dependence has the same functional form as the smooth soft-hard functional $Q^2$ dependence for po

Cristiana Bertolin

Let T be a Tannakian category over a field k of characteristic 0 and π(T) its fundamental group. In this paper we prove that there is a bijection between the otimes-equivalence classes of Tannakian subcategories of T and the normal affine group sub-T-schemes of π(T). We apply this result to the Tannakian category T_1(k) generated by motives of niveau \leq 1

Mordehai Milgrom, Robert H. Sanders

The recent findings of Romanowsky et al., of an ``unexpectedly&#39;&#39; small mass discrepancy within 5 effective radii in several elliptical galaxies, are not surprising in the context of MOND. As we show here, they are, in fact, in full concordance with its predictions. One is dealing with high-surface-density galaxies with mean accelerations rather large

M. Bowden, A. N. Taylor, K. M. Ganga, P. A. R. Ade

We investigate the science goals achievable with the upcoming generation of ground-based Cosmic Microwave Background polarization experiments and calculate the optimal sky coverage for such an experiment including the effects of foregrounds. We find that with current technology an E-mode measurement will be sample-limited, while a B-mode measurement will be

J Gersl, P Klepac, J Horsky

We give an example of a spacetime having an infinite thin rotating cylindrical shell constituted by a charged perfect fluid as a source. As the interior of the shell the Bonnor--Melvin universe is considered, while its exterior is represented by Datta--Raychaudhuri spacetime. We discuss the energy conditions and we show that our spacetime contains closed tim

S. Khochfar, A. Burkert

In order to specify cosmologically motivated initial conditions for major galaxy mergers (mass ratios $\leq$ 4:1) that are supposed to explain the formation of elliptical galaxies we study the orbital parameters of major mergers of cold dark matter halos using a high-resolution cosmological simulation. Almost half of all encounters are nearly parabolic with

F. Benatti, R. Floreanini, R. Romano

The generalized dynamics describing the propagation of neutral kaons in randomly fluctuating media is derived and analyzed. It takes into account possible matter-induced effects leading to loss of phase coherence and dissipation. The study of selected neutral kaon observables indicates that these non-standard effects are amenable to a direct experimental ana

Matt Visser

Taylor expanding the cosmological equation of state around the current epoch is the simplest model one can consider that does not make any a priori restrictions on the nature of the cosmological fluid. Most popular cosmological models attempt to be ``predictive'', in the sense that once somea priori equation of state is chosen the Friedmann equations are use

Chongxing Yue, Hongjie Zong, Lanjun Liu

We study a new method for detecting non-universal gauge bosons $Z&#39;$ via considering their effects on rare top decays. We calculate the contributions of the non-universal gauge bosons $Z&#39;$ predicted by topcolor-assisted technicolor (TC2) models and flavor-universal TC2 models on the rare top decays $t\longrightarrow cV(V=g,γ,Z)$ and $t\longrightarrow

Alexis Larranaga

We calculate the time delay between different relativistic images formed by the gravitational lensing produced by the Gibbons-Maeda-Garfinkle-Horowitz-Stromiger (GMGHS) charged black hole of heterotic string theory. Modeling the supermassive central objects of some galaxies as GMGHS black holes, numerical values of the time delays are estimated and compared

G. Gour, F. C. Khanna, M. Revzen

It is shown that any real and even function of the phase (time) operator has a self-adjoint extension and its relation to the general phase operator problem is analyzed.

Gao Ting, Wang Zhi-xi, Yan Feng-li

A simplification scheme of probabilistic teleportation of two-particle state of general form is given. By means of the primitive operations consisting of single-qubit gates, two-qubit controlled-not gates, Von Neumann measurement and classically controlled operations, we construct an efficient quantum logical network for implementing the new scheme of probab

Kiyotaka Kakazu

On the basis of the phase states, we present the correct integral expressions of the two number-phase Wigner functions discovered so far. These correct forms are derived from those defined in the extended Fock space with negative number states. The analogous conditions to Wigner&#39;s original ones cannot lead to the number-phase function uniquely. To show t

T. D. Ladd, D. Maryenko, E. Abe, K. M. Itoh

We report NMR experiments using high-power, RF decoupling techniques to show that a 29-Si nuclear spin qubit in a solid silicon crystal at room temperature can preserve quantum phase for 10^9 precessional periods. The coherence times we report are longer than for any other observed solid-state qubit by more than four orders of magnitude. In high quality crys

Stephen A. Fenner

We show that, for even n, evolving n qubits according to a simple Hamiltonian can be used to exactly implement an (n+1)-qubit parity gate, which is equivalent in constant depth to an (n+1)-qubit fanout gate. We also observe that evolving the Hamiltonian for three qubits results in an inversion-on-three-way-equality gate, which together with single-qubit oper

Alun Thomas, Rob Cannings, Nicholas A. M. Monk, Chris Cannings

We present a simple model for the underlying structure of protein-protein pairwise interaction graphs that is based on the way in which proteins attach to each other in experiments such as yeast two-hybrid assays. We show that data on the interactions of human proteins lend support to this model. The frequency of the number of connections per protein under t

Thomas S. Deisboeck, Yuri Mansury, Caterina Guiot, Piero Giorgio Degiorgis

Using our previously developed model we demonstrate here, that (1) solid tumor growth and cell invasion are linked, not only qualitatively but also quantitatively, that (2) the onset of invasion marks the time point when the tumor cell density exceeds a compaction maximum, and that (3) tumor cell invasion, reduction of mechanical confinement and angiogenesis

T Chaneliere, D Wilkowski, Y Bidel, R Kaiser

We use coherent backscattering (CBS) of light by cold Strontium atoms to study the mutual coherence of light waves in the multiple scattering regime. As the probe light intensity is increased, the atomic optical transition starts to be saturated. Nonlinearities and inelastic scattering then occur. In our experiment, we observe a strongly reduced enhancement

Xiao-Yan Gu, Zhong-Qi Ma, Jian-Qiang Sun

Complete spectrum of exact interdimensional degeneracies for a quantum $N$-body system in $D$-dimensions is presented by the method of generalized spherical harmonic polynomials. In an $N$-body system all the states with angular momentum $[μ+n]$ in $(D-2n)$ dimensions are degenerate where $[μ]$ and $D$ are given and $n$ is an arbitrary integer if the represe

Y. Ilieva

Differential cross sections of the gamma + d -> d + pi^0 reaction were measured at photon beam energies between 0.5 and 2.0 GeV over a wide angular range in CM system. The experiment was performed in Hall B at Jefferson Lab using the CLAS detector. The excitation function, especially at backward CM scattering angles, has been studied with regard to effects d

A. V. Yurov

We apply the method of dressing chains to reproduction of Toda lattice in the case of D=1 and D=2. On the example of modified equations $m_0TL$ and $m_1TL$ it is shown that combination of the Darboux and Schlesinger transformations results in closed dressing chains.

Stephan I. Tzenov

Based on the Vlasov-Maxwell equations describing the self-consistent nonlinear beam dynamics and collective processes, the evolution of an intense sheet beam propagating through a periodic focusing field has been studied. It has been shown that in the case of a beam with uniform phase space density the Vlasov-Maxwell equations can be replaced exactly by the

Saar Rahav, Oran Richman, Shmuel Fishman

The spectral statistics of the circular billiard with a point-scatterer is investigated. In the semiclassical limit, the spectrum is demonstrated to be composed of two uncorrelated level sequences. The first corresponds to states for which the scatterer is located in the classically forbidden region and its energy levels are not affected by the scatterer in

Andre X. C. N. Valente, N. H. McCLamroch, Igor Mezic

We consider two linearly coupled masses, where one mass can have inelastic impacts with a fixed, rigid stop. This leads to the study of a two degree of freedom, piecewise linear, frictionless, unforced, constrained mechanical system. The system is governed by three types of dynamics: coupled harmonic oscillation, simple harmonic motion and discrete rebounds.

José R. Salgueiro, Andreas Carlsson, Elena Ostrovskaya, Yuri Kivshar

We study the second-harmonic generation and localization of light in a reconfigurable waveguide induced by an optical vortex soliton in a defocusing Kerr medium. We show that the vortex-induced waveguide greatly improves conversion efficiency from the fundamental to the second harmonic field.

J. Frohlich, S. Gustafson, B. L. G. Jonsson, I. M. Sigal

We study the behavior of solitary-wave solutions of some generalized nonlinear Schrödinger equations with an external potential. The equations have the feature that in the absence of the external potential, they have solutions describing inertial motions of stable solitary waves. We construct solutions of the equations with a non-vanishing external potential

James Allen Fill, Fred Torcaso

We use Mellin transforms to compute a full asymptotic expansion for the tail of the Laplace transform of the squared $L^2$-norm of any multiply-integrated Brownian sheet. Through reversion we obtain corresponding strong small-deviation estimates.

David W. Kribs

We show that the representations of the Cuntz C$^\ast$-algebras $O_n$ which arise in wavelet analysis and dilation theory can be classified through a simple analysis of completely positive maps on finite-dimensional space. Based on this analysis, an application in quantum information theory is obtained; namely, a structure theorem for the fixed point set of