March 2000 arXiv papers — page 4

V. Frolov, D. Singh

We study quantum radiation generated by an accelerated motion of a small body with a refractive index n which differes slightly from 1. To simplify calculations we consider a model with a scalar massless field. We use the perturbation expansion in a small parameter n-1 to obtain a correction to the vacuum Hadamard function for a uniformly accelerated motion

Walter Simon

We show the following two extensions of the standard positive mass theorem (one for either sign): Let (N,g) and (N,g') be asymptotically flat Riemannian 3-manifolds with compact interior and finite mass, such that g and g' are twice Hoelder differentiable and related via the conformal rescaling g' = (phi^4).g, with a twice Hoelder differentiable

Yoshihiko Gotoh, Steve Renals

The rate of occurrence of words is not uniform but varies from document to document. Despite this observation, parameters for conventional n-gram language models are usually derived using the assumption of a constant word rate. In this paper we investigate the use of variable word rate assumption, modelled by a Poisson distribution or a continuous mixture of

Ronald Dickman, Miguel A. Munoz

Scaling properties of an interface representation of the critical contact process are studied in dimensions 1 - 3. Simulations confirm the scaling relation beta_W = 1 - theta between the interface-width growth exponent beta_W and the exponent theta governing the decay of the order parameter. A scaling property of the height distribution, which serves as the

S. F. Liotta

In this paper an asymptotic solution of the spherical harmonics equations describing the charge transport in semiconductors is found. This solution is compared with a numerical solution for bulk silicon device. We also indicate application of this solution to the construction of high field hydrodynamical models.

Alexander I. Olemskoi

On the basis of a dilatation invariant Lagrangian, governed equations are determined for probability density and gauge potential of the non-stationary self-similar stochastic system. It is shown that an automodel regime is observed at small time interval determined by the Tsallis' parameter $q>1$. An exponential falling down happens at large time where t

Stefano Zapperi, Hans J. Herrmann, Stephane Roux

We simulate the propagation of a planar crack in a quasi-two dimensional fuse model, confining the crack between two horizontal plates. We investigate the effect on the roughness of microcrack nucleation ahead of the main crack and study the structure of the damage zone. The two dimensional geometry introduces a characteristic length in the problem, limiting

M. Ogata, A. Himeda

A new type of analytic estimation of the effect of strong correlation is developed for the two-dimensional t-J model. It is based on the Gutzwiller approximation which gives the renormalization of parameters, t and J, due to the Gutzwiller's projection operator excluding the double occupancies. The finite-range correlations are taken into account compare

Yuh Tomio, Yoshikazu Suzumura

Several kinds of spin density wave (SDW) states with both quarter-filled band and dimerization are reexamined for a one-dimensional system with on-site, nearest-neighbor and next-nearest-neighbor repulsive interactions, which has been investigated by Kobayashi et al. (J. Phys. Soc. Jpn. 67 (1998) 1098). Within the mean-field theory, the ground state and the

Yunkyu Bang, Han-Yong Choi

Considering a possibility that the pseudogap state in the underdoped high-$T_{c}$ superconductors is not due to a superconducting correlation, we study the tunneling spectroscopy below $T_{c}$ based on the phenomenological models of the pseudogap state. Specifically we consider two cases: (1) the pseudogap is a simple suppression of the density of states wit

R. Sasik, T. Hwa

We study the pinning of vortices in thin film superconductors by magnetic dots in the London approximation. A single dot is in general able to pin multiple field-induced vortices, up to a saturation number n_s, which can be much larger than one. However, the magnetic field of the dot also creates intrinsic vortices and anti-vortices, which must be accounted

R. A. Gibbons, A. S. Fruchter, G. D. Bothun

We have fit the Fundamental Plane of Ellipticals (FP) to over 400 early-type galaxies in 20 nearby clusters (4000 < cz < 11000 km/s), using our own photometry and spectroscopy as well as measurements culled from the literature. We find that the quality-of-fit, r.m.s.[log(sigma)], to the average fundamental plane <FP> varies substantially among these clusters

J. W. Moffat

A brief review is given of the present observational data in cosmology. A review of a new bimetric gravity theory with multiple light cones is presented. The physical consequences of this gravity theory for the early universe are analyzed.

T. P. Greene, C. J. Lada

We present new high resolution (R = 21,000) near-infrared (2 microns) spectroscopic observations of a sample of Class I and flat-spectrum protostellar objects in the rho Ophiuchi dark cloud. None of the five Class I spectra show CO v = 0 -- 2 absorption features, consistent with high K-band continuum veilings, 4 <= r_k <= 20 and fast stellar rotation, assumi

Ulrich Kolb, Melvyn Davies, Andrew King, Hans Ritter

Cygnus X-2 appears to be the descendant of an intermediate-mass X-ray binary (IMXB). Using Mazzitelli&#39;s (1989) stellar code we compute detailed evolutionary sequences for the system and find that its prehistory is sensitive to stellar input parameters, in particular the amount of core overshooting during the main-sequence phase. With standard assumptions

W. S. Dias, R. Boczko, J. I. B. Camargo, R. Teixeira

Relative proper motions and cluster membership probabilities of 30 stars within an area of 14&#39; of diameter centered in the open cluster NGC1662 (α=04^{\rm h}48^{\rm m}, δ=+10^{\rm o}56&#39;) are determined by combining positions of stars observed by the Valinhos CCD meridian circle with those from other astrometric catalogues. Our basic source for first

Eric C. Zink, Dan F. Lester, Greg Doppmann, Paul M. Harvey

We have observed twenty two galaxies at 100 microns with the Kuiper Airborne Observatory in order to determine the size of their FIR emitting regions. Most of these galaxies are luminous far-infrared sources, with L_FIR > 10^11 L_sun. This data constitutes the highest spatial resolution ever achieved on luminous galaxies in the far infrared. Our data include

Andrea Comastri

The origin of the hard X-ray background (XRB) as a superposition of unabsorbed and absorbed Active Galactic Nuclei is now widely accepted as the standard model. The identification of faint X-ray sources in ROSAT, ASCA, and BeppoSAX medium-deep surveys and their average spectral properties are in broad agreement with the model predictions. However, AGN models

Letizia Stanghellini, Richard A. Shaw, Bruce Balick, J. Chris Blades

Planetary Nebulae (PNe) in the Large Magellanic Cloud (LMC) offer the unique opportunity to study both the Population and evolution of low- and intermediate-mass stars, by means of the morphological type of the nebula. Using observations from our LMC PN morphological survey, and including images available in the HST Data Archive, and published chemical abund

Laura Baudis, H. V. Klapdor-Kleingrothaus

The GENIUS project is a proposal for a large supersensitive Germanium detector system for WIMP and double beta decay searches with a much increased sensitivity relative to existing and other future experiments. In this paper, the possibility to detect low energy solar neutrinos with GENIUS in real-time through elastic neutrino-electron scattering is studied.

Laura Baudis, H. V. Klapdor-Kleingrothaus

Weakly Interacting Massive Particles (WIMPs) are leading candidates for the dominant part of the mass density of the Universe. Here we will review direct WIMP detection techniques by giving examples of currently running experiments, and present the status of the most promising future projects.

G. A. Verdoes Kleijn, R. P. van der Marel, C. M. Carollo, P. T. de Zeeuw

The peculiar elliptical galaxy IC 1459 (M_V = -21.19, D = 16.5 Mpc) has a fast counterrotating stellar core, stellar shells and ripples, a blue nuclear point source and strong radio core emission. We present results of a detailed HST study of IC 1459, and in particular its central gas disk, aimed a constraining the central mass distribution. We obtained WFPC

Akihiko Tomita, Kentaro Aoki, Masaru Watanabe, Tadafumi Takata

We investigated the central gas systems of E/S0 galaxies by making use of the WFPC2 images of the Hubble Space Telescope archive. We searched the gas systems that were traced by the dust with a new method of making color excess images in F555W - F814W (V-I). Out of 25 sample galaxies, we detected gas system in 14 galaxies. The dust was newly detected in two

Zakir F. Seidov

The characteristics of the star with the &#34;prescribed&#34; density distribution $ρ=ρ_c[1-(r/R)^α]$ are analytically studied.

Paul R. Shapiro, Ilian T. Iliev

A new model for the postcollapse equilibrium structure of virialized objects which condense out of the cosmological background universe is described and compared with observations and simulations of cosmological halos from dwarf galaxies to X-ray clusters. The model is based upon the assumption that virialized halos are isothermal, which leads to a predictio

L. H. Ford, N. F. Svaiter

The focusing of the vacuum modes of a quantized field by a parabolic mirror is investigated. We use a geometric optics approximation to calculate the energy density and mean squared field averages for scalar and electromagnetic fields near the focus. We find that these quantities grow as an inverse power of the distance to the focus. There is an attractive C

Stefano Liberati, Sebastiano Sonego, Matt Visser

Acoustic black holes are fluid dynamic analogs of general relativistic black holes, wherein the behaviour of sound waves in a moving fluid acts as an analog for scalar fields propagating in a gravitational background. Acoustic horizons possess many of the properties more normally associated with the event horizons of general relativity, up to and including H

J. M. Evans, A. J. Mountain

Every classical sigma-model with target space a compact symmetric space $G/H$ (with $G$ classical) is shown to possess infinitely many local, commuting, conserved charges which can be written in closed form. The spins of these charges run over a characteristic set of values, playing the role of exponents of $G/H$, and repeating modulo an integer $h$ which pl

Michael R. Douglas, Bartomeu Fiol, Christian Römelsberger

We begin the study of the spectrum of BPS branes and its variation on lines of marginal stability on O_P^2(-3), a Calabi-Yau ALE space asymptotic to C^3/Z_3. We show how to get the complete spectrum near the large volume limit and near the orbifold point, and find a striking similarity between the descriptions of holomorphic bundles and BPS branes in these t

Norman K. Glendenning, F. Weber

We study the spin evolution of X-ray neutron stars in binary systems, which are being spun up by mass transfer from accretion disks. Our investigation reveals that a quark phase transition resulting from the changing central density induced by the changing spin, can lead to a pronounced peak in the frequency distribution of X-ray neutron stars. This finding

W. M. Stuckey, Michael Silberstein

We introduce a pregeometry employing uniform spaces over the denumerable set X of spacetime events. The discrete uniformity D_X over X is used to obtain a pregeometric model of macroscopic spacetime neighborhoods. We then use a uniformity base generated by a topological group structure over X to provide a pregeometric model of microscopic spacetime neighborh

Richard J. Hill, G. Peter Lepage

We present a new, simplified analysis of the low-energy electron-positron interaction, and use the resulting effective theory to calculate the binding effects that contribute to the decay rate, Gamma, of orthopositronium, through Order(alpha^3 ln(alpha) Gamma). We express the total decay rate in terms of the annihilation rate for a free electron and positron

Ganpathy Murthy

The $ν=2$ quantum Hall state at low Zeeman coupling is well-known to be a translationally invariant singlet if Landau level mixing is small. At zero Zeeman interaction, as Landau level mixing increases, the translationally invariant state becomes unstable to aninhomogeneous state. This is the first realistic example of a full Hall crystal, which shows the co

Stavros Garoufalidis

The operation of (untwisted) Whitehead doubling trivializes the Alexander module of a knot (and consequently, all known abelian invariants), and converts knots to topologically slice ones. In this note we show that Whitehead doubling does not trivialize the rational function that equals to the 2-loop part of the Kontsevich integral.

F. Masset, M. Snellgrove

We present a mechanism related to the migration of giant protoplanets embedded in a protoplanetary disc whereby a giant protoplanet is caught up, before having migrated all the way to the central star, by a lighter outer giant protoplanet. This outer protoplanet may get captured into the 2:3 resonance with the more massive one, in which case the gaps that th

D. A. Head

A model for weakly excited granular media is derived by combining the free volume argument of Nowak et al. [Phys. Rev. E 57, 1971 (1998)] and the phenomenological model for supercooled liquids of Adam and Gibbs [J. Chem. Phys. 43, 139 (1965)]. This is made possible by relating the granular excitation parameter Γ, defined as the peak acceleration of the drivi

Sebastien Galtier

The study of the statistical distribution of short quiescent times ($\le$ 30 minutes) between solar flares has been investigated on a 1D MHD model. A power law behaviour is found which indicates the existence of sympathetic flaring. This prediction is supported by recent observations.

A. Bramon, R. Escribano, J. L. Lucio M., G. Pancheri

The ratio Phi->K+K-/K0K0bar is discussed and its present experimental value is compared with theoretical expectations. A difference larger than two standard deviations is observed. We critically examine a number of mechanisms that could account for this discrepancy, which remains unexplained. Measurements at DAPHNE at the level of the per mille accuracy can

A. B. Balantekin, N. Ozturk

We investigate the algebraic structure of the most general neutrino mass Hamiltonian and place the see-saw mechanism in an algebraic framework. We show that this Hamiltonian can be written in terms of the generators of an Sp(4) algebra. The Pauli-Gursey transformation is an SU(2) rotation which is embedded in this Sp(4) group. This SU(2) also generates the s

A. F. Zarnecki

Data from HERA, LEP and the Tevatron, as well as from low energy experiments are used to constrain the Yukawa couplings for scalar and vector leptoquarks in the Buchmuller-Ruckl-Wyler effective model. In the limit of very high leptoquark masses constraints on the coupling to the mass ratio l/M are derived using the contact-interaction approximation. For fini

Tuomas Multamaki, Iiro Vilja

Collisions of non-topological solitons, Q-balls, are studied in a typical potential in the Minimal Supersymmetric Standard Model where supersymmetry has been broken by a gravitationally coupled hidden sector. Q-ball collisions are studied numerically on a two dimensional lattice for a range of Q-ball charges. Total cross-sections, as well as cross-sections f

Janos Balog, Arpad Hegedus

We recalculate the two-loop beta functions in the two-dimensional Sine-Gordon model in a two-parameter expansion around the asymptotically free point. Our results agree with those of Amit et al., J. Phys. A13 (1980) 585.

Adam Lipowski

Using Monte Carlo simulations, we show that for a certain model of biological evolution, which is driven by non-extremal dynamics, active and absorbing phases are separated by a critical phase. In this phase both the density of active sites $ρ(t)$ and the survival probability of spreading $P(t)$ decay as $t^{-δ}$, where $δ\sim 0.5$. At the critical point, wh

Michael Frank

Hilbert(ian) A-modules over finite von Neumann algebras A with a faithful normal trace state (from global analysis) and Hilbert W*-modules over A (from operator algebra theory) are compared, and a categorical equivalence is established. The correspondence between these two structures sheds new light on basic results in $L^2$-invariant theory providing altern

Jose A. Font

The current status of numerical solutions for the equations of ideal general relativistic hydrodynamics is reviewed. With respect to an earlier version of the article the present update provides additional information on numerical schemes and extends the discussion of astrophysical simulations in general relativistic hydrodynamics. Different formulations of

C. J. S. Donald, D. M. Lucas, P. A. Barton, M. J. McDonnell

We report a precise search for correlation effects in linear chains of 2 and 3 trapped Ca+ ions. Unexplained correlations in photon emission times within a linear chain of trapped ions have been reported, which, if genuine, cast doubt on the potential of an ion trap to realize quantum information processing. We observe quantum jumps from the metastable 3d 2D

Pierre-Yves Gaillard

Let n and k be positive integers with and k < n. Then of course SU(k,1) is contained into SU(n,1). Moreover, which is less clear - but proved by Khoroshkin -, the representation theory of SU(k,1) at the generalized infinitesimal character of the trivial module can be fully (and even Ext-fully) embedded into that of SU(n,1). Here is the obvious bet: This embe

Horacio E. Camblong, Luis N. Epele, Huner Fanchiotti, Carlos A. Garcia Canal

This is the first in a series of papers addressing the phenomenon of dimensional transmutation in nonrelativistic quantum mechanics within the framework of dimensional regularization. Scale-invariant potentials are identified and their general properties are derived. A strategy for dimensional renormalization of these systems in the strong-coupling regime is

Christoph Kopper, Volkhard F. Müller, Thomas Reisz

We analyse 4-dimensional massive $\vp^4$ theory at finite temperature T in the imaginary-time formalism. We present a rigorous proof that this quantum field theory is renormalizable, to all orders of the loop expansion. Our main point is to show that the counterterms can be chosen temperature independent, so that the temperature flow of the relevant paramete

C. Alexandrou, R. Rosenfelder, A. W. Schreiber

Following Feynman&#39;s successful treatment of the polaron problem we apply the same variational principle to quenched QED in the worldline formulation. New features arise from the description of fermions by Grassmann trajectories, the supersymmetry between bosonic and fermionic variables and the much more singular structure of a renormalizable gauge theory

Alejandro Ayala, Sarira Sahu

We construct effective one-loop vertices and propagators in the linear sigma model at finite temperature, satisfying the chiral Ward identities and thus respecting chiral symmetry, treating the pion momentum, pion mass and temperature as small compared to the sigma mass. We use these objects to compute the two-loop pion self-energy. We find that the perturba

Paul Fendley, Robert M. Konik

The low-energy limits of models with disorder are frequently described by sigma models. In two dimensions, most sigma models admit either a Wess-Zumino-Witten or a theta term. When such a term is present the model can have a stable critical point with gapless excitations. We describe how such a critical point appears, in particular in two-dimensional superco

Sajeev John, Ovidiu Toader

In (quant-ph/9911099 version 1) A. Moroz claims that the exponent $η$ from the local photon density of states near a band gap edge $ρ(ω) = K(\vec{r}) |ω_c - ω|^η$ varies strongly with the position in the crystal. We show that this is not the case and we demonstrate the error in his analysis.

I. E. Mazets

We demonstrate that incoherent photon scattering by a Bose-Einstein condensate of non-ideal atomic gas is enhanced due to bosonic stimulation of spontaneous emission, similarly to coherent scattering in forward direction. Necessary initial population of non-condensate states is provided by quantum depletion of a condensate caused by interatomic repulsion.

V. Man&#39;ko, G. Marmo, A. Porzio, S. Solimeno

Some properties of the non--linear coherent states (NCS), recognized by Vogel and de Matos Filho as dark states of a trapped ion, are extended to NCS on a circle, for which the Wigner functions are presented. These states are obtained by applying a suitable displacement operator $D_{h}(α) $ to the vacuum state. The unity resolutions in terms of the projector

Le-Man Kuang, Hao-Sheng Zeng, Zhao-Yang Tong

We present a nonlinear decoherence model which models decoherence effect caused by various decohereing sources in a quantum system through a nonlinear coupling between the system and its environment, and apply it to investigating decoherence in nonclassical motional states of a single trapped ion. We obtain an exactly analytic solution of the model and find

Dirk Mueller, Eric A. Cornell, Marco Prevedelli, Peter D. D. Schwindt

A laser-cooled neutral-atom beam from a low-velocity intense source is split into two beams while guided by a magnetic-field potential. We generate our multimode-beamsplitter potential with two current-carrying wires on a glass substrate combined with an external transverse bias field. The atoms bend around several curves over a $10$-cm distance. A maximum i

M. P. Bora

An analysis of axisymmetric equilibria with arbitrary incompressible flow and finite resistivity is presented. It is shown that with large aspect ratio approximation or vanishing poloidal current, a uniform conductivity profile is consistent with equilibrium flows. Also a comment made on coexistence of both toroidal and poloidal flows in an axisymmetric fiel

A. Hoffknecht, C. Brandau, T. Bartsch, C. Boehme

Electron-ion recombination of completely stripped Bi83+ was investigated at the Experimental Storage Ring (ESR) of the GSI in Darmstadt. It was the first experiment of this kind with a bare ion heavier than argon. Absolute recombination rate coefficients have been measured for relative energies between ions and electrons from 0 up to about 125 eV. In the ene

K. V. Klementev

The problem of error analysis is addressed in stages beginning with the case of uncorrelated parameters and proceeding to the Bayesian problem that takes into account all possible correlations when a great deal of prior information about the accessible parametr space is available. The formulas for the standard deviations and deviations with arbitrary confide

K. V. Klementev

Three independent techniques are used to separate fine structure from the absorption spectra, the background function in which is approximated by (i) smoothing spline. We propose a new reliable criterion for determination of smoothing parameter and the method for raising of stability with respect to k_min variation; (ii) interpolation spline with the varied

C. B. Yang, X. Cai, Z. M. Zhou

A new type of spatial-temporal correlation in the process approaching to the self-organized criticality is investigated for the two simple models for biological evolution. The change behaviors of the position with minimum barrier are shown to be quantitatively different in the two models. Different results of the correlation are given for the two models. We

Dirk H. Rischke

I compute the gluon self-energy in a color superconductor with three flavors of massless quarks, where condensation of Cooper pairs breaks the color and flavor SU(3)_c x U(3)_V x U(3)_A symmetry of QCD to the diagonal subgroup SU(3)_{c+V}. At zero temperature, all eight electric gluons obtain a Debye screening mass, and all eight magnetic gluons a Meissner m

Véronique Bernard, Norbert Kaiser, Ulf-G. Meißner

We analyze a low-energy theorem of threshold pion electroproduction which allows one to determine the charge radius of the pion. We show that at the same order where the radius appears, pion loops induce a correction to the momentum dependence of the longitudinal dipole amplitude $L_{0+}^{(-)}$. This model-independent correction amounts to an increase of the

D. Drechsel

These lectures give an introduction to the structure of the nucleon as seen with the electromagnetic probe. Particular emphasis is put on the form factors, the strangeness content, Compton scattering and polarizabilities, pion photo- and electroproduction, the spin structure and sum rules. The existing data are compared to predictions obtained from chiral pe

J. -P. Eckmann, M. Hairer

We study stochastically forced semilinear parabolic PDE&#39;s of the Ginzburg-Landau type. The class of forcings considered are white noises in time and colored smooth noises in space. Existence of the dynamics in $L^\infty$, as well as existence of an invariant measure are proven. We also show that the solutions are with high probability analytic in a strip

Andrew Kresch, Harry Tamvakis

We prove the arithmetic Hodge index and hard Lefschetz conjectures for the Grassmannian $G=G(2,N)$ parametrizing lines in projective space, for the natural arithmetic Lefschetz operator defined via the Plücker embedding of $G$ in projective space. The analysis of the Hodge index inequalities involves estimates on certain Racah polynomials.

R. Pemantle, M. C. Wilson

Given a multivariate generating function F, we determine asymptotics for the coefficients. Our approach is to use Cauchy&#39;s integral formula near singular points of F, resulting in a tractable oscillating integral. This paper treats the case where the singular point of F is a smooth point of a surface of poles. Companion papers will treat singular points

Peter A. Linnell, Michael J. Puls

Let G be a discrete group, let $p \ge 1$, and let $L^p(G)$ denote the Banach space $\{\sum_{g\in G} a_g g \mid \sum_{g\in G} |a_g|^p < \infty\}$. The following problem will be studied: given $0 \ne α\in CG$ and $0 \ne β\in L^p(G)$, is $α* β\ne 0$? We will concentrate on the case G is a free abelian or free group.

Haisheng Li

For a vertex operator algebra $V$, the regular representations are related to the $A_{n}(V)$-algebras and their bimodules, and induced $V$-modules from $A_{n}(V)$-modules are defined and studied in terms of the regular representations.

D. V. Osipov

In 70&#39;s there was discovered a construction how to attach to some algebraic-geometric data an infinite-dimensional subspace in the space k((z)) of the Laurent power series. Now this construction is called the Krichever map. In e-print math.AG/9911097 A.N. Parshin suggested a generalization of the Krichever map for the case of algebraic surfaces from the

Eduardo Esteves, Nivaldo Medeiros

In the 80&#39;s D. Eisenbud and J. Harris posed the following question: &#34;What are the limits of Weierstrass points in families of curves degenerating to stable curves not of compact type?&#34; We answer their question for one-dimensional families of smooth curves degenerating to stable curves with just two components meeting at points in general position

K. Srinivasa Rao

The Life of Srinivasa Ramanujan (1887 - 1920), the renowned Indian Mathematician, is presented, in this the first of a series of lectures, delivered at the Indian Institute for Advanced Study, Shimla.

M. Giulietti, F. Pambianco, F. Torres, E. Ughi

We show that the set of F_q-rational points of either certain Fermat curves or certain F_q-Frobenius non-classical plane curves is a complete (k,d)-arc in P^2(F_q), where k and d are respectively the number of F_q-rational points and the degree of the underlying curve.

Angela Aguglia, Gabor Korchmaros, Fernando Torres

Some new results on plane F_{q^2}-maximal curves are stated and proved. It is known that the degree d of such curves is upper bounded by q+1 and that d=q+1 if and only if the curve is F_{q^2}-isomorphic to the Hermitian. We show that d\le q+1 can be improved to d\le (q+2)/2 apart from the case d=q+1 or q\le 5. This upper bound turns out to be sharp for q odd

Eduardo Cattani, Alicia Dickenstein, Bernd Sturmfels

A binomial residue is a rational function defined by a hypergeometric integral whose kernel is singular along binomial divisors. Binomial residues provide an integral representation for rational solutions of A-hypergeometric systems of Lawrence type. The space of binomial residues of a given degree, modulo those which are polynomial in some variable, has dim

Nistor Nicolaevici

We consider an abelian gauge theory with spontaneously broken symmetry containing a scalar-fermion coupling which is non-linear in the Higgs field. Although in the unitary gauge it reduces to a pure Yukawa term, suggesting that the theory is renormalizable, the one loop divergence structure in this gauge in the fermion-fermion elastic scattering amplitude sh

Nistor Nicolaevici

We obtain a series expansion for the one loop fermion contribution to the effective potential for constant A^a_μfields in SU(2) theory with a massive fermionic doublet. The series converges for bounded electric fields in terms of the magnetic fields and the gauge potentials. One finds that spontaneous fermion pair creation may be absent for arbitrary strong

A. Campbell-Smith, N. E. Mavromatos

We discuss a model in which our universe is pictured as a recoiling Dirichlet brane: we find that a proper treatment of the recoil leads naturally to supersymmetry obstruction on the four-dimensional world. An essential feature of our approach is the fact that the underlying worldsheet sigma model is non-critical, and the Liouville mode plays the role of the

Eric Bergshoeff, Antoine Van Proeyen

We show that the complete superalgebra of symmetries, including central charges, that underlies F-theories, M-theories and type II string theories in dimensions 12, 11 and 10 of various signatures correspond to rewriting of the same OSp(1|32) algebra in different covariant ways. One only has to distinguish the complex and the unique real algebra. We develop

Subir Ghosh

We show the presence of Poincare anomaly in Maxwell-Chern-Simons theory with an explicit mass term, in 2+1-dimensions.

J. -Q. Liang, H. J. W. Mueller-Kirsten, D. K. Park, A. V. Shurgaia

The transition from the quantum to the classical regime of the nucleation of the closed Robertson-Walker Universe with spacially homogeneous matter fields is investigated with a perturbation expansion around the sphaleron configuration. A criterion is derived for the occurrence of a first-order type transition, and the related phase diagram for scalar and ve

Matthias Braendle, Andre Lukas, Burt A. Ovrut

We study rolling radii solutions in the context of the four- and five-dimensional effective actions of heterotic M-theory. For the standard four-dimensional solutions with varying dilaton and T-modulus, we find approximate five-dimensional counterparts. These are new, generically non-separating solutions corresponding to a pair of five-dimensional domain wal

Richard Battye, Paul Sutcliffe

We investigate the dynamics of Q-balls in one, two and three space dimensions, using numerical simulations of the full nonlinear equations of motion. We find that the dynamics of Q-balls is extremely complex, involving processes such as charge transfer and Q-ball fission. We present results of simulations which illustrate the salient features of 2-Q-ball int

Andreas Nyffeler

Using a manifestly gauge-invariant approach we show that the set of low-energy constants in the electroweak chiral Lagrangian currently used in the literature is redundant. In particular, by employing the equations of motion for the gauge fields, one can choose to remove two low-energy constants which contribute to the self-energies of the gauge bosons. The

S. Groote, J. G. Körner

We review recent progress in the understanding of the physics of heavy baryons. We begin our review by presenting some highlights of recent experimental findings on charm and bottom baryons and briefly comment on their theoretical implications. On the theoretical side we review new results on the renormalization of HQET, on the Isgur-Wise function for $Λ_b \

Kingman Cheung, Otto C. W. Kong

We study the feasibility of incorporating the popular Zee model for neutrino mass in the framework of the supersymmetric standard model. While a singlet slepton has the right quantum number to play the role of the Zee charged scalar boson, the SUSY framework introduces extra contributions. We derive conditions for the Zee contributions to dominate, hence ret

G. Azuelos, U. Baur, J. van der Bij, D. Bourilkov

We review the prospects for studies in electroweak physics at the LHC.

Kh. M. Beshtoev

It is shown that the equation for Green&#39;s function of fermions (neutrinos) with weak interactions (in matter) coincides with the equation for Green&#39;s function of fermions in vacuum. This result is a consequence of the fact that the right components of fermions do not participate in weak interactions. As a result we come to a conclusion: the mechanism

S. Hesselbach, F. Franke, H. Fraas

We discuss associated neutralino production e^+ e^- --> \tildeχ^0_1 \tildeχ^0_2 with both beams polarized in the MSSM, NMSSM and an E_6 model. It is shown that neutralinos with a large singlino component can be produced at a high luminosity linear collider in a broad parameter range. Polarization effects in the extended models are compared over the whole par

S. Sultansoy

First of all, &#34;right&#34; sneutrino can be the lightest supersymmetric particle. Then, the flavor democracy favors large value of the tan^($beta$). Finally, the huge number of free parameters in the three families MSSM may be considered as an indication of SUSY at preonic level.

C. M. Carloni Calame, C. Lunardini, G. Montagna, O. Nicrosini

The luminosity determination of electron-positron colliders operating in the region of low-lying hadronic resonances (E_cm ~ 1-10 GeV), such as BEPC/BES, DAPHNE, KEKB, PEP-II and VEPP-2M, requires the precision calculation of the Bhabha process at large scattering angles. In order to achieve a theoretical accuracy at a few 0.1% level, the inclusion of radiat

Shun&#39;ichi Tanaka

Using anomalous U(1) symmetry the quark mass texture is determined uniquely. We analyze squark mass spectrum based on the above mass matrices and discuss the possibility to solve the problems of FCNC and CP caused by complex phases of soft terms, including the viewpoint of M theory.

Christopher Kolda

At moderate to large tan(beta), it is no longer possible to simultaneously diagonalize the masses of quarks and their couplings to the neutral Higgs bosons. The resulting flavor violations of the form (\bar b_R d_L H) and (\bar b_R s_L H) do not generate large meson-anti-meson mixing amplitudes but do generate large contributes to rare decays such as B_s ->

A. Dedes, P. Kanti

We consider the embedding of the Standard Model fields in a $(4+d)$-dimensional theory while gravitons may propagate in $d&#39;$ extra, compact dimensions. We study the modification of strengths of the gravitational and gauge interactions and, for various values of $d$ and $d&#39;$, we determine the energy scale at which these strengths are unified. Special

Laurent Lellouch, Martin Lüscher

The two-body decay rate of a weakly decaying particle (such as the kaon) is shown to be proportional to the square of a well-defined transition matrix element in finite volume. Contrary to the physical amplitude, the latter can be extracted from finite-volume correlation functions in euclidean space without analytic continuation. The K -> pi pi transitions a

Grant Gorfine, Martin Hoeferkamp, Geno Santistevan, Sally Seidel

Capacitance measurements have been made on silicon pixel sensors of types n+ on n, p+ on n, and n+ on p. The arrays test a variety of implant and gap widths, and the n+ on n devices test several p-stop designs. The measurements examine inter-pixel and backplane contributions and include studies of temperature dependence. Measurements were made before and aft

Leonard Parker, Alpan Raval

In a new model that we proposed, nonperturbative vacuum contributions to the effective action of a free quantized massive scalar field lead to a cosmological solution in which the scalar curvature becomes constant after a time $t_j$ (when the redshift $z \sim 1$) that depends on the mass of the scalar field and its curvature coupling. This spatially-flat sol

Zoltán Perjés

The Einstein-Maxwell fields of rotating stationary sources are represented by the SU(2,1) spinor potential $Ψ_A$ satisfying \[ \nabla \cdot [Θ^{-1}(Ψ_A\nabla Ψ_B-Ψ_B\nabla Ψ_A)]=-2Θ^{-2}\vec{C}\cdot (Ψ_A\nabla Ψ_B-Ψ_B\nabla Ψ_A) \] where $Θ=Ψ^{\dagger }\cdot Ψ$ is the SU(2,1) norm of $Ψ$% . The Ernst potentials are expressed in terms of the spinor potential

Krzysztof R. Apt

We study here the well-known propagation rules for Boolean constraints. First we propose a simple notion of completeness for sets of such rules and establish a completeness result. Then we show an equivalence in an appropriate sense between Boolean constraint propagation and unit propagation, a form of resolution for propositional logic. Subsequently we char