September 1999 arXiv papers — page 7

Monica Valluri, David Merritt

The orbits of stars in galaxies are generically chaotic: the chaotic behavior arises in part from the intrinsically grainy nature of a potential that is composed of point masses. Even if the potential is assumed to be smooth, however, orbits in non-axisymmetric galaxies can be chaotic due to the presence of central density cusps or black holes. The chaotic n

Eric F. Bell, Roelof S. de Jong

We have used a large sample of low-inclination spiral galaxies with radially-resolved optical and near-infrared photometry to investigate trends in star formation history with radius as a function of galaxy structural parameters. A maximum likelihood method was used to match all the available photometry of our sample to the colours predicted by stellar popul

Eric F. Bell, David Barnaby, Richard G. Bower, Roelof S. de Jong

We have performed deep imaging of a diverse sample of 26 low surface brightness galaxies (LSBGs) in the optical and the near-infrared. Using stellar population synthesis models, we find that it is possible to place constraints on the ratio of young to old stars (which we parameterise in terms of the average age of the galaxy), as well as the metallicity of t

B. M. Gaensler, E. V. Gotthelf, G. Vasisht

We report on Very Large Array observations in the direction of the recently-discovered slow X-ray pulsar AX J1845-0258. In the resulting images, we find a 5-arcmin shell of radio emission; the shell is linearly polarized with a non-thermal spectral index. We class this source as a previously unidentified, young (< 8000 yr), supernova remnant (SNR), G29.6+0.1

Juergen Prahl

An unbinned statistical test on cluster-like deviations from Poisson processes for point process data is introduced, presented in the context of time variability analysis of astrophysical sources in count rate experiments. The measure of deviation of the actually obtained temporal event distribution from that of a Poisson process is derived from the distribu

Avinash A. Deshpande, Joanna M. Rankin

The beautiful sequences of ``drifting&#39;&#39; subpulses observed in some radio pulsars have been regarded as among the most salient and potentially instructive characteristics of their emission, not least because they have appeared to represent a system of subbeams in motion within the emission zone of the star. Numerous studies of these ``drift&#39;&#39;

R. A. Flores, A. H. Maller, J. R. Primack

The frequency with which background galaxies appear as long arcs as a result of gravitational lensing by foreground clusters of galaxies has recently been found to be a very sensitive probe of cosmological models by Bartelmann et al. (1998). They have found that such arcs would be expected far less frequently than observed (by an order of magnitude) in the c

B. M. Gaensler, R. N. Manchester, L. Staveley-Smith, V. Wheaton

The interaction between the ejecta from Supernova 1987A and surrounding material is producing steadily brightening radio and X-ray emission. The new-born supernova remnant has been significantly decelerated by this interaction, while its morphology reflects the axisymmetric nature of the progenitor wind.

Simone Bianchi, Andrea Ferrara, Jon Davies, Paul Alton

We present Monte Carlo radiative transfer simulations for spiral galaxies modelled as a stellar disk and a two-phase clumpy dust distribution. We divide the volume occupied by the dust into a three-dimensional grid and assign each cell a clump or smooth medium status. Cell dimension, clump dust mass and spatial distribution are derived from the observed prop

Willy Kley

The discovery of now about 20 extrasolar planets orbiting solar-type stars with properties quite different from those in our Solar System has raised many questions about the formation and evolution of planets. The tidal interaction between the planet and the surrounding disk determines the orbital properties and the mass of the planet. We have performed nume

H. Tsunemi, E. Miyata, B. Aschenbach

Several shrapnels have been detected in the vicinity of Vela SNR by the ROSAT all-sky survey. We present here the spectral properties of shrapnel `A&#39; observed with the ASCA satellite. A prominent Si-K emission line with relatively weak emission lines from other elements have been detected, revealing that the relative abundance of Si is a few ten-times hi

V. S. Titov, P. Demoulin, G. Hornig

Although the analysis of observational data indicates that quasi-separatrix layers (QSLs) have to play an important role in magnetic configurations of solar flares, the corresponding theory is only at an initial stage so far. In particular, there is still a need in a proper definition of QSL. This problem is analyzed here on the basis of geometrical properti

Thomas M. Brown, Charles W. Bowers, Randy A. Kimble, Allen V. Sweigart

We present the deepest near-UV image of M32 to date, which for the first time resolves hot HB stars in an elliptical galaxy. Given the near-solar metallicity of M32, much larger than that of globular clusters, the existence of an extended HB is a striking example of the 2nd parameter effect, and, most importantly, provides direct evidence that hot HB stars a

Fulvio Pompilio, Fabio La Franca, Giorgio Matt

We discuss the constraints on the AGN evolution from the cosmic X-ray background and source counts. A synthesis model to fit the X-ray background is presented. In the model, the spectrum of type 2 AGN has been modeled including Compton down--scattering within the absorbing material. Besides, we introduced a dependence on redshift of the relative number of ob

M. Lopez-Corredoira, J. E. Beckman, E. Casuso

The High-Velocity Clouds (HVCs) observed in the Galactic neighbourhood, have been proposed to be remnants of the formation of the galaxies in the Local Group, having distances, and thus masses, predominantly of dark matter, considerably larger than hitherto hypothesized. This hypothesis is plausibly supported by observational evidence that their kinematical

D. K. Galloway, A. B. Giles, J. G. Greenhill, M. C. Storey

The X-ray pulsar GX 1+4 was observed with the RXTE satellite for a total of 51ks between 1996 July 19 - 21. During this period the flux decreased smoothly from an initial mean level of ~ 6 X 10^36 erg/s to a minimum of ~ 4 X 10^35 erg/s (2-60 keV, assuming a source distance of 10 kpc) before partially recovering towards the initial level at the end of the ob

Ikuru Iwata, Shin-ichiro Okumura, Mamoru Saito

We found that at least 18 Young Stellar Object candidates invisible at optical and near-infrared wavelengths, as well as ^12CO emission. They are IRAS point sources with FIR colors similar to those of usual YSOs, and the infrared spectral indices between 2.2 um and 25 um correspond to those of class I YSOs. These peculiar far-infrared objects are highly conc

Abhas Mitra

We invoke the global properties of the actual GTR field equations for spherical collapse to directly show that the condition for formation of trapped surfaces, 2GM/R >1 is not allowed by GTR. And therefore all singularity theorems based on the assumption of formation of trapped surfaces are invalidated! Our conclusion is in perfect agreement with Einstein&#3

Bruce A. Bassett, Christopher Gordon, Roy Maartens, David I. Kaiser

The relative growth of field and metric perturbations during preheating is sensitive to initial conditions set in the preceding inflationary phase. Recent work suggests this may protect super-Hubble metric perturbations from resonant amplification during preheating. We show that this possibility is fragile and sensitive to the specific form of the interactio

P. Kanti, I. I. Kogan, K. A. Olive, M. Pospelov

We analyze cosmological equations in the brane world scenario with one extra space-like dimension. We demonstrate that the cosmological equations can be reduced to the usual 4D Friedmann type if the bulk energy-momentum tensor is different from zero. We then generalize these equations to the case of a brane of finite thickness. We also demonstrate that when

John T. Whelan, William Krivan, Richard Price

The quasi-stationary method for black hole binary inspiral is an approximation for studying strong field effects while suppressing radiation reaction. In this paper we use a nonlinear scalar field toy model (i) to explain the underlying method of approximating binary motion by periodic orbits with radiation; (ii) to show how the fields in such a model are fo

M. Brhlik, L. Everett, G. L. Kane, S. F. King

Recently it has been demonstrated that large phases in softly broken supersymmetric theories are consistent with electric dipole moment constraints, and are motivated in some (Type I) string models. Here we consider whether large flavor-independent soft phases may be the dominant (or only) source of all CP violation. In this framework $ε$ and $ε&#39;/ε$ can

JM Figueroa-O&#39;Farrill, S Stanciu

We re-examine the problem of determining the possible D-branes in the Nappi-Witten background. In addition to the known branes, we find that there are also D-instantons, flat euclidean D-strings and curved D-membranes admitting parallel spinors, all of which can be interpreted as (twisted) conjugacy classes in the Nappi-Witten group.

L. Sandoval

It is shown how to sew string vertices with ghosts at tree level in order to produce new tree vertices using the Group Theoretic approach to String Theory. It is then verified the BRST invariance of the sewn vertex and shown that it has the correct ghost number.

Michael Gronau, Jonathan L. Rosner

The decays of $B$ mesons to charmless final states consisting of a vector meson ($V$) and a pseudoscalar meson ($P$) are analyzed within flavor SU(3). Predictions are compared with new data from the CLEO Collaboration. Dominant contributions to amplitudes and subdominant interfering terms are identified. Evidence is found for a specific penguin amplitude (co

Haim Goldberg

The lepton asymmetry created in the out-of-equilibrium decay of a heavy Majorana neutrino can generate the cosmological baryon asymmetry when processed through fast anomalous electroweak reactions. In this work I examine this process under the following assumptions: (1) maximal nu_mu/nu_tau mixing (2) hierarchical mass spectrum m_3 >> m_2 (3) small-angle MSW

Nickolay Y. Gnedin

I use cosmological simulations that incorporate a physically motivated approximation to three-dimensional radiative transfer that recovers correct asymptotic ionization front propagation speeds for some cosmologically relevant density distributions transfer to investigate the process of the reionization of the universe by ionizing radiation from proto-galaxi

K. S. Babu, Christopher Kolda

In this letter we demonstrate a new source for large flavor-changing neutral currents within the minimal supersymmetric standard model. At moderate to large tan(beta), it is no longer possible to diagonalize the masses of the quarks in the same basis as their Yukawa couplings. This generates large flavor-violating couplings of the form $\bar b_R d_L H$ and $

Fang Shi, T. G. Steele, V. Elias, K. B. Sprague

A Hoelder inequality analysis of the QCD Laplace sum-rule which probes the non-strange (n\bar n) components of the I={0,1} (light-quark) scalar mesons supports the methodological consistency of an effective continuum contribution from instanton effects. This revised formulation enhances the magnitude of the instanton contributions which split the degeneracy

W. Beenakker, F. A. Berends, A. P. Chapovsky

We propose a novel procedure for handling processes that involve unstable intermediate particles. By using gauge-invariant effective Lagrangians it is possible to perform a gauge-invariant resummation of (arbitrary) self-energy effects. For instance, gauge-invariant tree-level amplitudes can be constructed with the decay widths of the unstable particles prop

Vahid Rezania, Roy Maartens

The spin rate Ωof neutron stars at a given temperature T is constrained by the interplay between gravitational-radiation instabilities and viscous damping. Navier-Stokes theory has been used to calculate the viscous damping timescales and produce a stability curve for r-modes in the (Ω,T) plane. In Navier-Stokes theory, viscosity is independent of vorticity,

V. Cirigliano, J. F. Donoghue, E. Golowich

We express the leading electromagnetic corrections in K-> pi pi amplitudes as integrals over the virtual photon squared-momentum Q^2. The high Q^2 behavior is obtained via the operator product expansion. The low Q^2 behavior is calculated using chiral perturbation theory. We model the intermediate Q^2 region using resonance contributions in order to enforce

Dmitri Antonov, Dietmar Ebert

We review the string representations of Abelian-projected SU(2)- and SU(3)-gauge theories and their application to the evaluation of bilocal field strength correlators. The large distance asymptotic behaviours of the latter ones are shown to be in agreement with the Stochastic Vacuum Model of QCD and existing lattice data.

Samim Erhan, Peter E. Schlein

A further analysis of inelastic diffraction data at the ISR and SPS-Collider confirms the relatively flat s-independent pomeron trajectory in the high-|t| domain, 1-2 GeV^2, reported earlier by the UA8 Collaboration. At |t| = 1.5 GeV^2, alpha = 0.92 +/- 0.03 is in agreement with the trajectories found in diffractive photoproduction of vector mesons at HERA.

Masafumi Koike, Joe Sato

Stimulated by the idea of PRISM, a very high intensity muon ring with rather low energy, we consider possibilities of observing CP-violation effects in neutrino oscillation experiments. More than 10% of CP-violation effect can be seen within the experimentally allowed region. Destructive sum of matter effect and CP-violation effect can be avoided with use of

John McDonald

We consider the conditions for the decay products of perturbative inflaton decay to thermalize. The importance of considering the full spectrum of inflaton decay products in the thermalization process is emphasized. It is shown that the delay between the end of inflaton decay and thermalization allows the thermal gravitino upper bound on the reheating temper

S. L. Dubovsky, D. S. Gorbunov

Recently it was proposed that matching of global charges induced in vacuum by slowly varying, topologically non-trivial scalar fields provides consistency conditions analogous to the &#39;t Hooft anomaly matching conditions. We study matching of induced charges in supersymmetric SU(N) gauge theories with quantum modified moduli space. We find that the Wess-Z

C. Helm, C. Preis, C. Walter, J. Keller

In this publication a microscopic theory for the coupling of intrinsic Josephson oscillations in layered superconductors with longitudinal c-axis-phonons is developed. It is shown that the influence of lattice vibrations on the c-axis transport can be fully described by introducing an effective longitudinal dielectric function. Resonances in the I-V-characte

Stefan Rauch-Wojciechowski, Krzysztof Marciniak, Hans Lundmark

Systems of Newton equations of the form $\ddot{q}=-{1/2}A^{-1}(q)\nabla k$ with an integral of motion quadratic in velocities are studied. These equations generalize the potential case (when A=I, the identity matrix) and they admit a curious quasi-Lagrangian formulation which differs from the standard Lagrange equations by the plus sign between terms. A theo

Saburo Kakei

The coupled KP hierarchy, introduced by Hirota and Ohta, are investigated by using the dressing method. It is shown that the coupled KP hierarchy can be reformulated as a reduced case of the 2-component KP hierarchy.

Saburo Kakei

Orthogonal and symplectic matrix integrals are investigated. It is shown that the matrix integrals can be considered as a $τ$-function of the coupled KP hierarchy, whose solution can be expressed in terms of pfaffians.

G. D. Sanders, K. W. Kim, W. C. Holton

We propose a quantum computer structure based on coupled asymmetric single-electron quantum dots. Adjacent dots are strongly coupled by means of electric dipole-dipole interactions enabling rapid computation rates. Further, the asymmetric structures can be tailored for a long coherence time. The result maximizes the number of computation cycles prior to loss

P. Narayana Swamy

Just as for the ordinary quantum harmonic oscillators, we expect the zero-point energy to play a crucial role in the correct high temperature behavior. We accordingly reformulate the theory of the statistical distribution function for the q-deformed boson oscillators and develop an approximate theory incorporating the zero-point energy. We are then able to d

Miloslav Znojil

A class of short-range potentials on the line is considered as an asymptotically vanishing phenomenological alternative to the popular confining polynomials. We propose a method which parallels the analytic Hill-Taylor description of anharmonic oscillators and represents all our Jost solutions non-numerically, in terms of certain infinite hypergeometric-like

Arvind, Kavita Dorai, Anil Kumar

A scheme to execute an n-bit Deutsch-Jozsa (D-J) algorithm using n qubits has been implemented for up to three qubits on an NMR quantum computer. For the one and two bit Deutsch problem, the qubits do not get entangled, hence the NMR implementation is achieved without using spin-spin interactions. It is for the three bit case, that the manipulation of entang

Amit Kr. Chattopadhyay, Abhik Basu, Jayanta K. Bhattacharjee

We find that studying the simplest of the coupled non-equilibrium growth equations of Barabasi by self-consistent mode coupling requires the use of dressed vertices. Using the vertex renormalization, we find a roughness exponent which already in the leading order is quite close to the numerical value.

Peter Schmelcher, Lorenz S. Cederbaum

We report on a number of recently discovered phenomena which arise due to the interaction of the collective (CM) and internal motion of atoms moving in magnetic fields. For neutral atoms the properties of the so-called giant dipole states are discussed and their experimental preparation is outlined. For ions moving in magnetic fields the energy flow between

Jon J. V. Maestri, Rubin H. Landau, Manuel J. Paez

A simple and explicit technique for the numerical solution of the two-particle, time-dependent Schrödinger equation is assembled and tested. The technique can handle interparticle potentials that are arbitrary functions of the coordinates of each particle, arbitrary initial and boundary conditions, and multi-dimensional equations. Plots and animations are gi

Benoit T. Guay

A propulsion generated without propellent mass and external forces using a well known physics is possible theoretically. To do that, it is proposed to use two specific time-varying and constrained distributions of electric charges which own a symmetry axis and are adequately separated in space. Total charge of each distribution is zero. With a relative tempo

G. Krein, D. P. Menezes, M. Nielsen, C. Providencia

The quark-meson-coupling model is used to study droplet formation from the liquid-gas phase transition in cold asymmetric nuclear matter. The critical density and proton fraction for the phase transition are determined in the mean field approximation. Droplet properties are calculated in the Thomas-Fermi approximation. The electromagnetic field is explicitly

V. D. Efros, W. Leidemann, G. Orlandini, E. L. Tomusiak

Inclusive electromagnetic reactions in few-nucleon systems are studied basing on accurate three- and four-body calculations. The longitudinal 4He(e,e&#39;) response function obtained at q\le 600 MeV/c completely agrees with experiment. The exact 4He spectral function obtained in a semirealistic potential model is presented, and the accuracy of the quasielast

Q. Zhao

In this work, an improved quark model approach to the $ω$ meson photoproduction with an effective Lagrangian is reported. The {\it t}-channel {\it natural} parity exchange is consistently taken into account through the Pomeron exchange, while the {\it unnatural} parity exchange is described by the $π^0$ exchange. It shows that with very limited number of par

Q. Zhao, J. -P. Didelez, M. Guidal, B. Saghai

The resonance effects are investigated in the $ϕ$ meson photoproduction near threshold through a quark model approach with an effective Lagrangian. The diffractive contribution is consistently estimated by the {\it t}-channel Pomeron exchange. Another non-diffractive process, {\it t}-channel $π^0$ exchange is also included. The numerical result shows that th

F. V. Kusmartsev, K. E. Kurten, H. S. Dhillon

We discuss stationary solutions of the nonlinear Schrodinger equation (NSE) applicable to several quantum spin, electron and classical lattice systems. We show that there may arise chaotic spatial structures in the form of incommensurate or irregular quantum states and trajectories in space. As a first (typical) example we consider a single electron which is

V. D. Gladush, R. A. Konoplya

There has been proposed a new method of the constructing of the basic functions for spaces of tensor representations of the Lie groups with the help of the generalized Casimir operator. In the definition of the operator there were used the Lie derivatives instead of the corresponding infenitisemal operators. When introducing the generalized Casimir operator

Alex Chigogidze, Vesko Valov

Extension dimension is characterized in terms of $ω$-maps. We apply this result to prove that extension dimension is preserved by refinable maps between metrizable spaces. It is also shown that refinable maps preserve some infinite-dimensional properties.

Eric Weber

An examination of the translation invariance of $V_0$ under dyadic rationals is presented, generating a new equivalence relation on the collection of wavelets. The equivalence classes under this relation are completely characterized in terms of the support of the Fourier transform of the wavelet. Using operator interpolation, it is shown that several equival

Eric Weber

This paper examines the wavelet multiplicity function. An explicit formula for the multiplicity function is derived. An application to operator interpolation is then presented. We conclude with several remarks regarding the wavelet connectivity problem.

Sa&#39;ar Hersonsky, Frederic Paulin

Let M be a geometrically finite pinched negatively curved Riemannian manifold with at least one cusp. Inspired by the theory of diophantine approximation of a real (or complex) number by rational ones, we develop a theory of approximation of geodesic lines starting from a given cusp by ones returning to it. We define a new invariant for M, the {\it Hurwitz c

Heather Johnston, Andrew Ranicki

The Bryant-Ferry-Mio-Weinberger surgery exact sequence for high-dimensional compact ANR homology manifolds is used to obtain transversality, splitting and bordism results for homology manifolds, generalizing previous work of Johnston.

Justin Roberts

The SU(2) TQFT representation of the mapping class group of a closed surface of genus g, at a root of unity of prime order, is shown to be irreducible. Some examples of reducible representations are also given.

Gueo Grantcharov, Liviu Ornea

We show that the contact reduction can be specialized to Sasakian manifolds. We link this Sasakian reduction to Kähler reduction by considering the Kähler cone over a Sasakian manifold. We present examples of Sasakian manifolds obtained by $S^1$ reduction of standard Sasakian spheres.

S Stanciu

In this paper we re-examine the geometric interpretation of gluing conditions in WZW models and the possible D-brane configurations that they give rise to. We show how the boundary conditions are encoded in the gluing conditions imposed on the chiral currents. We analyse two special classes of gluing conditions: the first, which preserves the affine symmetry

L. Sandoval

In this article, it is shown how to obtain objects called Eichler integrals in the mathematical literature that can be used for calculating scattering amplitudes in String Theory. These Eichler integrals are also new examples of Eichler integrals with poles.

B. Kleihaus, Jutta Kunz

We discuss the asymptotic form of the static axially symmetric, globally regular and black hole solutions, obtained recently in Einstein-Yang-Mills and Einstein-Yang-Mills-dilaton theory.

Masud Chaichian, Kazuhiko Nishijima

In connection with the question of color confinement the origin of the Goto-Imamura-Schwinger term has been studied with the help of renormalization group. An emphasis has been laid on the difference between theories with and without a cut-off.

Masud Chaichian, Kazuhiko Nishijima

Color confinement is a consequence of an unbroken non-Abelian gauge symmetry and the resulting asymptotic freedom inherent in quantum chromodynamics. A qualitative sketch of its proof is presented.

Germar Schroeder

Generators for the discrete U-duality groups of toroidally compactified M-theory in d>3 are presented and used to determine the d=3 U-duality group. This contribution summarizes the results of hep-th/9909150.

P. Bain

We discuss some aspects of the generalization of the Born-Infeld action to non-abelian gauge groups and show how the discrepancy between Tseytlin&#39;s symmetrized trace proposal and string theory can be corrected at order $F^6$. We also comment on the possible quadratic order fermionic terms.

H. Babujian, M. Karowski

Using the methods of the &#34;form factor program&#34; exact expressions of all matrix elements are obtained for several operators of the quantum sine Gordon model: all powers of the fundamental bose field, general exponentials of it, the energy momentum tensor and all higher currents. It is found that the quantum sine-Gordon field equation holds with an exa

R. Rapp

We discuss the recent status in the theoretical understanding of dilepton production in central heavy-ion reactions with the Pb-beam at the full CERN-SpS energy of 158 AGeV. In the low-mass region ($M\le$~1 GeV) a strong broadening of the vector meson resonances in hot and dense matter (especially for the $ρ$ meson) entails thermal dilepton rates very remini

Sz. Borsanyi, A. Patkos, Zs. Szep

We have calculated the damping rate $Γ(|{\bf k}|)$ for classical on-shell Goldstone modes of the O(2) symmetric scalar fields propagating in a thermal medium of the broken symmetry phase taking into account the effect of the explicit symmetry breaking. The result of the one-loop analysis can be expanded around $Γ(0)$, which depends non-analytically on the pa

J. R. Hiller

Techniques for the field-theoretic calculation of a form factor are described and applied to a dressed-fermion state of a (3+1)-dimensional model Hamiltonian. Discrete light-cone quantization plays the crucial role as the means by which Fock-state wave functions are computed. An ultraviolet infinity is controlled by Pauli-Villars regularization.

Stephan Narison

For some experimental guidelines of the next millenium, I review the determinations of the masses, decays and mixings of the gluonia, scalar and hybrid mesons from QCD spectral sum rules and low-energy theorems, and compare them with the lattice.

Kees de Jager, Bernard Pire

We review recent progress in the experimental knowledge of and theoretical speculations about nucleon form factors, with special emphasis on the large Q2 region.

Zhou Mian-Lai, Ma Wen-Gan, Han Liang, Jiang Yi

We studied the one-loop contributions of the gaugino-Higgsino-sector to the process of top-pair production via $γγ$ fusion at NLC in frame of the Minimal Supersymmetric Model(MSSM). We find that the corrections to $γγ\to t\bar{t}$ and $e^+ e^- \to γγ\to t\bar{t}$ are found to be significant and can approach to a few percent and one percent, respectively. Fur

Carlo Giunti

It is shown that at least four massive neutrinos are needed in order to accommodate the evidences in favor of neutrino oscillations found in solar and atmospheric neutrino experiments and in the LSND experiment. Among all four-neutrino schemes, only two are compatible with the results of all neutrino oscillation experiments. These two schemes have a mass spe

Ilya F. Ginzburg, Maria Krawczyk, Per Osland

We consider the two effective couplings hZγand hγγinvolving a neutral scalar Higgs boson with a mass around 100 GeV in the Standard Model, in the Two Higgs Doublet Model, and in the Minimal Supersymmetric Standard Model. The couplings can be tested at Photon Colliders, and used to distinguish these models.

P. C Beggio, M. J. Menon, P. Valin

We construct the hadronic multiplicity distribution in terms of an elementary distribution (at given impact parameter) and the inelastic overlap function characterized by the observed BEL (Blacker-Edgier-Larger) behaviour. With suitable parametrizations for the elementary quantities, based on some geometrical arguments and the most recent data on e+e- annihi

N. Eicker, C. Best, Th. Lippert, K. Schilling

It is shown that the 21264 Alpha processor can reach about 20% sustained efficiency for the inversion of the Wilson-Dirac operator. Since fast ethernet is not sufficient to get balancing between computation and communication on reasonable lattice- and system-sizes, an interconnection using Myrinet is discussed. We find a price/performance ratio comparable wi

Harald Markum, Wolfgang Sakuler, Stefan Thurner

We classify the lattice by elementary 3-cubes which are associated to dual links occupied by, or free of monopoles. We then compute the quark condensate, the quark charge and the chiral density on those cubes. By looking at distributions we demonstrate that monopole trajectories carry considerably more chirality with respect to the free vacuum.

E. -M. Ilgenfritz, S. Thurner

Using the renormalization group based smoothing technique we have studied the gauge invariant field strength correlator at T\ne0 and T=0 in pure SU(2) gauge theory. In conjunction with a cluster analysis, the field strength correlator is used to study correlations between the clusters in space and color orientation.

F. Karsch, P. Petreczky

We study propagators of the lattice 3d adjoint Higgs model, considered as an effective theory of 4d SU(2) gauge theory at high temperature. The propagators are calculated in so-called lambda-gauges. From the long distance behaviour of the propagators we extract the screening masses. It is shown that the pole masses extracted from the propagators agree well w

V. M. Ghete

The studies of Fermi-Dirac correlations of $ΛΛ$ and $\barΛ\barΛ$ pairs in hadronic $\mathrm{Z}$ decays, Bose-Einstein correlations and colour reconnection in $\mathrm{W}$-pairs decays performed by the ALEPH collaboration in $\mathrm{e^+e^-}$ annihilation at LEP are presented. The OPAL analysis of Bose-Einstein correlations in $\mathrm{W}$-pair decays is also

Klaus Eitel

A combined statistical analysis of the experimental results of the LSND and KARMEN numubar->nuebar oscillation search is presented. LSND has evidence for neutrino oscillations that is not confirmed by the KARMEN experiment. However, there is a region in the (sin^2(2theta),Dm^2) parameter space where the results of both experiments are statistically compatibl

David D. Reid

This paper provides a thorough introduction to the causal set hypothesis aimed at students, and other interested persons, with some knowledge of general relativity and nonrelativistic quantum mechanics. I elucidate the arguments for why the causal set structure might be the appropriate structure for a theory of quantum gravity. The logical and formal develop

S. Micciche, J. B. Griffiths

A new approach to the inverse-scattering technique of Alekseev is presented which permits real-pole soliton solutions of the Ernst equations to be considered. This is achieved by adopting distinct real poles in the scattering matrix and its inverse. For the case in which the electromagnetic field vanishes, some explicit solutions are given using a Minkowski

L. K. Patel, Naresh Dadhich, R. Tikekar

Three families of exact solutions of Einstein field equations are found. Each family contains three parameters. Two of these families represent thick domain walls in a five dimensional Kaluza-Klein spacetime. The dynamical behaviour of our models is briefly discussed. The spacetime in all the cases is found to be reflection symmetric with respect to the wall

William M. Pezzaglia

Systems of equations are invariant under &#34;polydimensional transformations&#34; which reshuffle the geometry such that what is a line or a plane is dependent upon the frame of reference. This leads us to propose an extension of Clifford calculus in which each geometric element (vector, bivector) has its own coordinate. A new classical action principle is

W. Losert, J. -C. Geminard, S. Nasuno, J. P. Gollub

Several mechanisms cause a granular material to strengthen over time at low applied stress. The strength is determined from the maximum frictional force F_max experienced by a shearing plate in contact with wet or dry granular material after the layer has been at rest for a waiting time τ. The layer strength increases roughly logarithmically with τ-only- if

J. A. Chervenak, J. M. Valles,

We present low temperature measurements of the resistance in magnetic field of superconducting ultrathin amorphous Bi films with normal state sheet resistances, $R_N$, near the resistance quantum, $R_Q={\hbar\over {e^2}}$. For $R_N<R_Q$, the tails of the resistive transitions show the thermally activated flux flow signature characteristic of defect motion in

E. Somfai, L. M. Sander

We use atomistic simulations with an empirical potential (EAM) to study the elastic effects of heteroepitaxial islands on adatom diffusion. We measure the diffusion barrier on pure stressed substrate and near a misfit island, as well as the detachment barrier from islands of different size.

Sandeep K. Joshi, Debendranath Sahoo, A. M. Jayannavar

We report a detailed and systematic study of wave propagation through a stochastic absorbing random medium. Stochastic absorption is modeled by introducing an attenuation constant per unit length $α$ in the free propagation region of the one-dimensional disordered chain of delta function scatterers. The average value of the logarithm of transmission coeffici

Luis Craco, Mukul S. Laad

We study the dielectric response of correlated systems which undergo a Mott transition as a function of band filling within the dynamical mean field framework. We compute the dielectric figure of merit (DFOM), which is a measure of dielectric efficiency and an important number for potential device applications. It is suggested how the DFOM can be optimized i

H. J. Luo, L. Schuelke, B. Zheng

Short-time dynamic scaling behavior of the 3D $\pm J$ Ising spin glass is studied by Monte Carlo methods. Starting the replicas with independent initial configurations with a small pseudo magnetization, the dynamic evolution of the overlap q(t) between two replicas is measured. The initial increase of the overlap q(t) is observed and the corresponding expone

B. Zheng

We numerically solve microscopic deterministic equations of motion for the 2D $ϕ^4$ theory with random initial states. Phase ordering dynamics is investigated. Dynamic scaling is found and it is dominated by a fixed point corresponding to the minimum energy of random initial states.

B. Zheng

Numerically we solve the microscopic deterministic equations of motion with random initial states for the two-dimensional $ϕ^4$ theory. Scaling behavior of the persistence probability at criticality is systematically investigated and the persistence exponent is estimated.

B. Zheng, M. Schulz, S. Trimper

Taking the two-dimensional $ϕ^4$ theory as an example, we numerically solve the deterministic equations of motion with random initial states. Short-time behavior of the solutions is systematically investigated. Assuming that the solutions generate a microcanonical ensemble of the system, we demonstrate that the second order phase transition point can be dete

S. Okamoto, S. Ishihara, S. Maekawa

Roles of orbital degree of freedom of Mn ions in phase transition as a function of temperature and hole concentration in perovskite manganites are studied. It is shown that the orbital order-disorder transition is of the first order in the wide region of hole concentration and the N$\rm \acute{e}$el temperature for the anisotropic spin ordering, such as the

V. Penna

Quantum dynamics of a vortex pair is investigated by considering the pair Hamiltonian within various, unequivalent algebraic frameworks. First the vortex pair spectrum is constructed in the standard contest of the e(2)-like dynamical symmetry and its degeneracy is thoroughly examined. Then the Berry phase phenomenon is studied through an su(1,1) realization