June 1993 arXiv papers — page 3

M. Grady

It is shown that a Coulomb potential using a running coupling slightly modified from the perturbative form can produce an interquark potential that appears nearly linear over a large distance range. Recent high-statistics SU(2) lattice gauge theory data fit well to this potential without the need for a linear string-tension term. This calls into question the

Olivier Debarre

Let $Θ$ be a symmetric theta divisor on an indecomposable principally polarized complex abelian variety $X$. The linear system $|2Θ|$ defines a morphism $K:X\ra |2Θ|^*$, whose image is the Kummer variety $K(X)$ of $X$. When $(X,θ)$ is the Jacobian of an algebraic curve, there are infinitely many trisecants lines to $K(X)$. Welters has conjectured that the ex

B. Machet

We show how a spontaneously broken gauge theory of fermions endowed with a composite scalar multiplet becomes naturally anomaly-free, and yet describes the correct couplings of the pion to two gauge fields and to leptons: the first coupling is the same as computed from the chiral anomaly, and the second identical with that obtained from the `Partially Conser

Esa Karjalainen

We solve explicitly a closed, linear loop equation for the SU(2) Wilson loop average on a two-dimensional plane and generalize the solution to the case of the SU(N) Wilson loop average with an arbitrary closed contour. Furthermore, the flat space solution is generalized to any two-dimensional manifold for the SU(2) Wilson loop average and to any two-dimensio

Don N. Page

If black hole formation and evaporation can be described by an $S$ matrix, information would be expected to come out in black hole radiation. An estimate shows that it may come out initially so slowly, or else be so spread out, that it would never show up in an analysis perturbative in $M_{Planck}/M$, or in 1/N for two-dimensional dilatonic black holes with

G. Krein, A. W. Thomas, A. G. Williams

The momentum-dependence of the $ρ^0$-$ω$ mixing contribution to charge-symmetry breaking (CSB) in the nucleon-nucleon interaction is compared in a variety of models. We focus in particular on the role that the structure of the quark propagator plays in the predicted behaviour of the $ρ^0$-$ω$ mixing amplitude. We present new results for a confining (entire)

Adrian Neagu, Adriaan M. J. Schakel

A gas of electrons confined to a plane is examined in both the relativistic and nonrelativistic case. Using a (0+1)-dimensional effective theory, a remarkably simple method is proposed to calculate the spin density induced by an uniform magnetic background field. The physical properties of possible fluxon excitations are determined. It is found that while in

M. Cavicchi, P. Di Vecchia, I. Pesando

We rewrite the action for $QCD_2$ in the light cone gauge only in terms of a bilocal mesonic field. In this formalism the $1/N$ expansion can be done in a straightforward way by a saddle point technique that determines the master field to be identified with the vacuum expectation value of the bilocal field. Finally we show that the equation of motion for the

Samir D. Mathur

In the first quantised description of strings, we integrate over target space co-ordinates $X^μ$ and world sheet metrics $g_{αβ}$. Such path integrals give scattering amplitudes between the `in' and `out' vacuua for a time-dependent target space geometry. For a complete description of `particle creation' and the corresponding backreaction, we nee

H. J. de Vega, A. González--Ruiz

The general solutions for the factorization equations of the reflection matrices $K^{\pm}(θ)$ for the eight vertex and six vertex models (XYZ, XXZ and XXX chains) are found. The associated integrable magnetic Hamiltonians are explicitly derived, finding families dependig on several continuous as well as discrete parameters.

G. Papadopoulos, B. Spence

A new parameterisation of the solutions of Toda field theory is introduced. In this parameterisation, the solutions of the field equations are real, well-defined functions on space-time, which is taken to be two-dimensional Minkowski space or a cylinder. The global structure of the covariant phase space of Toda theory is examined and it is shown that it is i

Sandu Popescu, Lev Vaidman

Consequences of relativistic causality for measurements of nonlocal characteristics of composite quantum systems are investigated. It is proved that verification measurements of entangled states necessarily erase local information. A complete analysis of measurability of nondegenerate spin operators of a system of two spin-1/2 particles is presented. It is s

Lev Vaidman

We report results of an investigation of relativistic causality constraints on the measurability of nonlocal variables. We show that measurability of certain nondegenerate variables with entangled eigenstates contradicts the principle of causality, but that there are other, certainly nonlocal, variables which can be measured without breaking causality. We sh

Renata Kallosh, Tomas Ortin

We have found generic Killing spinor identities which bosonic equations of motion have to satisfy in supersymmetric theories if the solutions admit Killing spinors. Those identities constrain possible quantum corrections to bosonic solutions with unbroken supersymmetries. As an application we show that purely electric static extreme dilaton black holes may a

Jaemo Park, Piljin Yi

We study the mass-charge relation for the semiclassical extremal black hole of the $S$-wave sector Einstein-Maxwell theory coupled to $N$ conformal scalars. The classical ratio $M/{|Q|}=1$ is shown to be modified to $M/{|Q|} \simeq 1-k/6$ for small $ k \equiv N\hbar/(12πQ^{2})$. Furthermore, numerical study for $k<2$ shows that $M/|Q|$ is a monotonically dec

F. E. Close, R. G. Roberts

The recent measurements of lepton nucleon scattering with polarised neutron and deuteron targets are analysed together with the previous polarised proton data in a mutually consistent way. The detailed $x$-dependence of the polarisation asymmetry in the valence region is shown to be in agreement with historical predictions based on quark models. The Bjorken

F. E. Close

When the new data on polarised lepton nucleon scattering are compared at the same value of $Q^2$ and with a common set of assumptions, a consistent picture of the spin content of the nucleon begins to emerge. Higher order effects in $0(α_s)$, higher twist effects, modern data on unpolarised structure functions and an updated value for F/D are all important i

J. Chýla

Direct and resolved photon interactions are shown to be intimately related through the factorization mechanism. It is argued that in theoretically consistent analysis of jet production in $γ$p and ep collisions the LO resolved $γ$ contribution must be considered together with the NLO direct $γ$ component. Recent data from HERA therefore do not provide a dire

B. de Carlos, J. A. Casas, C. Munoz

The general SUSY soft breaking terms for a large class of phenomenologically relevant string scenarios (symmetric orbifolds) are given. They show a certain lack of universality, but not dangerous for flavor changing neutral currents. To get more quantitative results a specific SUSY breaking mechanism has to be considered, namely gaugino condensation in the h

Viqar Husain

In recent work on Einstein gravity in four dimensions using the Ashtekar variables, non-local loop variables have played an important role in attempts to formulate a quantum theory. The introduction of such variables is guided by gauge invariance, and here an infinite set of loop variables is introduced for the Hamiltonian form of the Einstein-Maxwell theory

D. Garfinkle, S. B. Giddings, A. Strominger

Pair production of Reissner-Nordstrom black holes in a magnetic field can be described by a euclidean instanton. It is shown that the instanton amplitude contains an explicit factor of $e^{A/4}$, where $A$ is the area of the event horizon. This is consistent with the hypothesis that $e^{A/4}$ measures the number of black hole states.

K. A. Matveev, Dongxiao Yue, L. I. Glazman

The conductance of a weakly interacting electron gas in the presense of a single scatterer is found at arbitrary strength of the scattering potential. At weak interaction, a simple renormalization group approach can be used instead of the standard bosonization procedure. Our technique allows to take into account the {\em backscattering\/} of electrons that l

Enrique cerda, Fernando Lund

Vortical flows in shallow water interact with long surface waves by virtue of the nonlinear terms of the fluid equations. Analytical formulae are derived that quantify the spontaneous generation of such waves by unsteady vorticity as well as the scattering of surface waves by vorticity. In a first Born approximation the radiated surface elevation is linearly

M. Fatuzzo, F. Melia

Highly dynamic magnetospheric perturbations in neutron star environments can naturally account for the features observed in Gamma-ray Burst spectra. The source distribution, however, appears to be extragalactic. Although noncatastrophic isotropic emission mechanisms may be ruled out on energetic and timing arguments, MHD processes can produce strongly anisot

Douglas C. Heggie

This review concentrates almost entirely on globular star clusters. It emphasises the increasing realisation that few of the traditional problems of star cluster astronomy can be studied in isolation: the influence of the Galaxy affects dynamical evolution deep in the core, and the spectrum of stellar masses; in turn the evolution of the core determines the

Pavel Bleher

We prove that the error term $\La(R)$ in the Weyl asymptotic formula $$\#\{ E_n\le R^2\}={\Vol M\over 4π} R^2+\La(R),$$ for the Laplace operator on a surface of revolution $M$ satisfying a twist hypothesis, has the form $\La(R) =R^{1/2}F(R)$ where $F(R)$ is an almost periodic function of the Besicovitch class $B^2$, and the Fourier series of $F(R)$ in $B^2$

Laurent Houart

No change at all but this time is possible to typset it!.

Damiano Anselmi, Pietro Fre&#39;

It is well-known that topological sigma-models in 2 dimensions constitute a path-integral approach to the study of holomorphic maps from a Riemann surface S to an almost complex manifold K, the most interesting case being that where K is a Kahler manifold. We show that, in the same way, topological sigma-models in 4 dimensions introduce a path integral appro

Giovanni Modanese

We give a general expression for the static potential energy of the gravitational interaction of two massive particles, in terms of an invariant vacuum expectation value of the quantized gravitational field. This formula holds for functional integral formulations of euclidean quantum gravity, regularized to avoid conformal instability. It could be regarded a

R. Bijker, A. Leviatan

We present an algebraic U(7) model for baryons which encompasses both single-particle and collective forms of quark dynamics. The mass operator by construction preserves the permutation symmetry between identical quarks. The underlying geometric structure of baryons is discussed in terms of a rigid rotating and vibrating oblate top shape. The model is applie

P. A. Henning

Thermo Field Dynamics for inhomogeneous systems is generalized to quantum fields with a continuous single-particle mass spectrum. The modification of the hamiltonian in states with a local thermal Bogoliubov symmetry is used to calculate thermal conductivity and diffusion coefficient of pions interacting with hot, compressed nuclear matter.

G. E. Arutyunov

The method of geometrical quantization of symplectic manifolds is applied to constructing infinite dimensional irreducible unitary representations of the algebra of functions on the compact quantum group $SU_q(2)$. A formulation of the method for the general case $SU_q(n)$ is suggested. (This work is the English version of the article submitted for publicati

E. Ragoucy

I show that the classical Toda models built on superalgebras, and obtained from a reduction with respect to an $Sl(2)$ algebra, are &#34;linearly supersymmetrizable&#34; (by adding spin 1/2 fields) if and only if the $Sl(2)$ is the bosonic part of an $OSp(1|2)$ algebra. In that case, the model is equivalent to the one constructed from a reduction with respec

A. Matytsin

We study the large N limit of the Itzykson -- Zuber integral and show that the leading term is given by the exponent of an action functional for the complex inviscid Burgers (Hopf) equation evaluated on its particular classical solution; the eigenvalue densities that enter in the IZ integral being the imaginary parts of the boundary values of this solution.

R. Guida, K. Konishi, N. Magnoli

We study the level crossing of the fermion system described by the euclidean Dirac Hamiltonian in the valley background. One chiral fermion level is shown to cross twice the zero value in the case of well-separated instanton-anti-instanton background. Below a critical separation, however, level crossings are absent. The phenomenon can be interpreted as the t

R. N. Mohapatra

There are strong indications for neutrino masses and mixings in the data on solar neutrinos as well as in the observed deficit of muon neutrinos from the atmosphere. The COBE data and other analysis of the large scale structure in the Universe also seems to require a hot component in the universe&#39;s dark matter, which can be interpreted as a massive neutr

R. I. Steinberg

We discuss the Chooz experiment, a long baseline search for neutrino vacuum oscillations, which will utilize a large gadolinium-loaded liquid scintillation detector one km from a large nuclear power station in France. The 300-meter (water equivalent) underground site of the detector reduces cosmic ray muons, the main source of background in this type of expe

M. Lindner

We discuss how the full dynamics of top condensation models can modify the relations between the physical top mass, the amount of custodial $SU(2)$ violation and the weak gauge boson masses. It is emphasized that it is possible to get phenomenologically acceptable relations between $Δρ$, $m_t$ and $M_W$ and that in addition the scale of new physics can be ch

S. D. Ellis

Recent progress in the perturbative analysis of hadronic jets, especially in the context of hadron colliders, is discussed. The characteristic feature of this work is the emergence of a level of precision in the study of the strong interactions far beyond that previously possible. Inclusive cross sections for high energy jets at the Tevatron are now perturba

L. Karkkainen, P. Lacock, D. E. Miller, B. Petersson

In the high temperature phase of Yang-Mills theories, large spatial Wilson loops show area law behaviour with a string tension that grows with increasing temperature. Within the framework of the commonly used string picture we use a large scale expansion, which allows us to determine the string tension from measurements of intermediate and symmetric Wilson l

M. I. Polikarpov, Ken Yee

&#39;t~Hooft&#39;s abelian projection of $SU(N)$ gauge theory yields $N$ mutually constrained, compact abelian fields which are permutationally equivalent. We formulate the notion of ``species permutation&#39;&#39; symmetry of the $N$ abelian projection fields and discuss its consequences for cross-species correlators. We show that at large $N$ cross-species

J. Gamboa, Y. Georgelin

We study two dimensional dilaton gravity and supergravity following hamiltonian methods. Firstly, we consider the structure of constraints of 2D dilaton gravity and then the 2D dilaton supergravity is obtained taking the squere root of the bosonic constraints. We integrate exactly the equations of motion in both cases and we show that the solutions of the eq

N. V. Prokof&#39;ev

We study the response of the interacting electron gas in one dimension on the local external potential. In the low frequency limit the power-law singularities are essentially modifyed by backscattering effects which, in the case of zero forward scattering, result in the universal critical exponent depending only on the Luttinger-liquid interactions. The resu

J. J. Arenzon, R. M. C. de Almeida

We present results for two different kinds of high order connections between neurons acting as corrections to the Hopfield model. Equilibrium properties are analyzed using the replica mean-field theory and compared with numerical simulations. An optimal learning algorithm for fourth order connections is given that improves the storage capacity without increa

Gerhard Fasol, Hiroyuki Sakaki

A microscopic picture of electron-electron pair scattering in single mode quantum wires is introduced which includes electron spin. A new source of `excess&#39; noise for hot carriers is presented. We show that zero magnetic field `spin&#39; splitting in quantum wires can lead to a dramatic `spin&#39;-subband dependence of electron--electron scattering, incl

B. Holdom, R. A. Malaney

We propose a mechanism by which the neutrino emission from a supernova-type explosion can be converted into a gamma-ray burst of total energy $\sim 10^{50}$ ergs. This occurs naturally if the explosion is situated inside a ball of trapped neutrinos, which in turn may lie at a galactic core. There are possible unique signatures of this scenario.

B. Rush, M. A. Malkan, L. Spinoglio

We have selected an all--sky sample of 893 galaxies from the IRAS FSC--2, defined by a total (ADDSCAN) 12um flux limit of 0.22~Jy. Completeness is verified to 0.30~Jy, below which we have quantified the incompleteness down to 0.22~Jy for our statistical analysis. ¶The Seyfert subsample is the largest unbiased sample of (118) Seyfert galaxies ever assembled a

Guillermo Fernandez del Busto

The purpose of this note is to show how the Kawamata-Viehweg vanishing theorem for fractional divisors leads to a quick new proof of Bogomolov&#39;s instability theorem for rank two vector bundles on an algebraic surface.

M. R. Abolhassani, F. Ardalan

We introuduce a unified method which can be applied to any WZW model at arbitrary level to search systematically for modular invariant physical partition functions. Our method is based essentially on modding out a known theory on group manifold $G$ by a discrete group $Γ$. We apply our method to $\widehat {su(n)}$ with $n=2,3,4,5,6$, and to $\widehat {g_2}$

Giancarlo cella, Giuseppe Curci, Raffaele Tripiccione, Andrea Vicere&#39;

We report on a high statistics simulation of SU(2) pure gauge field theory at finite temperature, using Symanzik action. We determine the critical coupling for the deconfinement phase transition on lattices up to 8 x 24, using Finite Size Scaling techniques. We find that the pattern of asymptotic scaling violation is essentially the same as the one observed

L. Susskind, L. Thorlacius, J. Uglum

Three postulates asserting the validity of conventional quantum theory, semi-classical general relativity and the statistical basis for thermodynamics are introduced as a foundation for the study of black hole evolution. We explain how these postulates may be implemented in a ``stretched horizon&#39;&#39; or membrane description of the black hole, appropriat

Peter A. Clarkson, Elizabeth L. Mansfield

Classical and nonclassical symmetries of the nonlinear heat equation $$u_t=u_{xx}+f(u),\eqno(1)$$ are considered. The method of differential Gröbner bases is used both to find the conditions on $f(u)$ under which symmetries other than the trivial spatial and temporal translational symmetries exist, and to solve the determining equations for the infinitesimal

R. Rapp, J. Wambach

We examine a hot pion gas by including medium modifications of the two-body scattering amplitude as well as mean-field effects selfconsistently. In contrast to earlier calculations, the in-medium T-matrix is rather close to the free one while the mean-field potential agrees well with lowest-order estimates. We also discuss the validity of the quasiparticle a

Walter D. Neumann, Michael Shapiro

We study the synchronous and asynchronous automatic structures on the fundamental group of a graph of groups in which each edge group is finite. Up to a natural equivalence relation, the set of biautomatic structures on such a graph product bijects to the product of the sets of biautomatic structures on the vertex groups. The set of automatic structures is m

Michael Shapiro

Anisimov and Seifert show that a group has a regular word problem ifand only if it is finite. Muller and Schupp (together with Dunwoody&#39;s accessibility result) show that a group has context free word problem if and only if it is virtually free. In this note, we exhibit a class of groups where the word problem is as close as possible to being a context se

John R. Stallings

In ``A remark about the description of free products of groups&#39;&#39;, Proc. Cambgridge Philos. Soc 62(1966), io ha studite lo que occurre in le circumstantia que un gruppo $G$ ha un subensemble $P$ tal que tote elemento de $G$ es representabile unicamente per un verbo reducite in $P$. Il eveni que tal $P$ es multo como un producto libere. Que occurre qua

Michael Shapiro, Melany Stein

If $M$ is a closed Nil geometry 3-manifold then $π_1(M)$ is almost convex with respect to a fairly simple ``geometric&#39;&#39; generating set. If $G$ is a central extension or a ${\Bbb Z}$-extension of a word hyperbolic group, then $G$ is also almost convex with respect to some generating set. Combining these with previously known results shows that if $M$

Hoi-Kwong Lo

Exact wavefunctions for N non-Abelian Chern-Simons (NACS) particles are obtained by the ladder operator approach. The same method has previously been applied to construct exact wavefunctions for multi-anyon systems. The two distinct base states of the NACS particles that we use are multi-valued and are defined in terms of path ordered line integrals. Only st

R. Jackiw

An alternative to Dirac&#39;s constrained quantization procedure is explained.

Jens Erler

After pointing out the role of the compactification lattice for spectrum calculations in orbifold models, I discuss modular discrete symmetry groups for $Z_N$ or\-bi\-folds. I consider the $Z_7$ orbifold as a nontrivial example of a (2,2) model and give the generators of the modular group for this case, which does not contain $[SL(2,{\bf Z})]^3$ as had been

M. C. Diamantini, P. Sodano, C. A. Trugenberger

We construct a lattice model of compact (2+1)-dimensional Maxwell-Chern- Simons theory, starting from its formulation in terms of gauge invariant quantities proposed by Deser and Jackiw. We thereby identify the topological excitations and their interactions. These consist of monopolo- antimonopole pairs bounded by strings carrying both magnetic flux and elec

Amir Aghamohammadi

We present an alternative 2-parametric deformation $ GL(2)_{h,h&#39;} $ , and construct the differential calculus on the quantum plane on which this quantum group acts. Also we give a new deformation of the two dimensional Heisenberg algebra

Takashi Mishima, Akika Nakamichi

We apply CGHS-type dilaton gravity model to (1+1)-dimensional cosmological situations. First the behavior of a compact 1-dimensional universe (i.e. like a closed string) is classified on the assumption of homogeneity of universe. Several interesting solutions are found, which include a Misner-type universe having closed time-like curves, and an asymptoticall

V. Barger, R. J. N. Phillips

We review some recent results and future prospects in the phenomenology of Supersymmmetry. We discuss the searches for superpartner states, the searches for Higgs bosons in the minimal SUSY model, and additional parameter constraints arising in SUSY-GUT models.

Zurab G. Berezhiani, Anna Rossi

Effects of the dense matter can induce the neutrino decay even if neutrinos are stable in vacuum. This is due to coherent interactions with matter which lead to energy level-splitting between the neutrino and antineutrino states and thereby provide available phase space for the majoron emission. We show that the matter induced decay can be a plausible candid

P. Marenzoni, L. Pugnetti, P. Rossi

We report on a study of the autocorrelation times of the local version of the Hybrid Monte Carlo (LHMC) algorithm for pure gauge $SU(3)$. We compare LHMC to standard multi-hit Metropolis and to the global version of the same HMC. For every algorithm we measure the autocorrelation time for a variety of observables and the string tension as a function of beta.

Wolfgang Bock, Jan Smit, Jeroen C. Vink

As a first step towards constructing chiral models on the lattice with staggered fermions, we study a U(1) model with axial-vector coupling to an external gauge field in two dimensions. In our approach gauge invariance is broken, but it is restored in the classical continuum limit. We find that the continuum divergence relations for the vector and axial-vect

Gerhard Rein, Alan D. Rendall

The initial value problem for the Vlasov-Poisson system is by now well understood in the case of an isolated system where, by definition, the distribution function of the particles as well as the gravitational potential vanish at spatial infinity. Here we start with homogeneous solutions, which have a spatially constant, non-zero mass density and which descr

Gerhard Rein, Alan D. Rendall, Jack Schaeffer

In a previous paper two of the authors (G. R. and A. D. R.) showed that there exist global, classical solutions of the spherically symmetric Vlasov-Einstein system for small initial data. The present paper continues this investigation and allows also large initial data. It is shown that if a solution of the spherically symmetric Vlasov-Einstein system develo

Víctor M. Villalba

In the present article, using a further generalization of the algebraic method of separation of variables, the Dirac equation is separated in a family of space-times where it is not possible to find a complete set of first order commuting differential operators. After separating variables, the Dirac equation is reduced to a set of coupled ordinary differenti

R. J. Radtke

In a recent article, Kim and Overhauser [Phys. Rev. B 47, 8025 (1993)] have found fault with the theory of impure superconductors by Abrikosov and Gor&#39;kov and have proposed an alternative formalism based on Green&#39;s functions which are not derivable from a Dyson equation. Although the corrections to the Abrikosov-Gor&#39;kov theory found by Kim and Ov

E. S. Sorensen, I. Affleck

Using the recently proposed density matrix renormalization group technique we show that the magnons in the S=1 antiferromagnetic Heisenberg chain effectively behaves as bosons that condense at a critical field h_c.

Mark Srednicki

The fluctuations in the cosmic microwave background radiation may contain deviations from gaussian statistics which would be reflected in a nonzero value of three-point correlation function of $ΔT$. However, any potential observation of the three-point function is limited by cosmic variance, even if a whole-sky map of $ΔT$ is available. Here I derive a gener

A. N. Taylor, M. Rowan-Robinson

We present a new method for extracting the true 3-d velocity and density fields from the nonlinear redshift--space projected density field. The method is based on the nonlinear, nonlocal transformation of the density field. We assume a curl--free velocity field, although in the formulation presented here this assumption can be dropped. Toy models with specia

H. -J. Matschull, H. Nicolai

We discuss the canonical treatment and quantization of matter coupled supergravity in three dimensions, with special emphasis on $N=2$ supergravity. We then analyze the quantum constraint algebra; certain operator ordering ambiguities are found to be absent due to local supersymmetry. We show that the supersymmetry constraints can be partially solved by a fu

S. Aoki, Y. Kikukawa

Abelian anomaly is examined by means of the recently proposed gauge invariant regularization for SO(10) chiral gauge theory and its generalization for a theory of arbitrary gauge group with anomaly-free chiral fermion contents. For both cases it is shown that the anomaly with correct normalization can be obtained in a gauge invariant form without any counter

T. S. Biro, J. Zimanyi

We speculate about a heavy bottom-charm six-quark baryon. A semiclassical and a gaussian estimate reveal that the octet-octet bbb-ccc configuration can be energetically favored with respect to the singlet-singlet one. This result suggests that a confined bbb-ccc six-quark state may exist. Such objects may be produced in appreciable amount in heavy ion collis

Menachem Kojman, Saharon Shelah

We prove that mu = mu^{< mu}, 2^mu = mu^+ and ``there is a non reflecting stationary subset of mu^+ composed of ordinals of cofinality < mu&#39;&#39; imply that there is a mu-complete Souslin tree on mu^+ .

Martin Goldstern, Haim Judah, Saharon Shelah

If ZFC is consistent, then each of the following are consistent with ZFC + 2^{aleph_0}= aleph_2 : 1.) X subseteq R is of strong measure zero iff |X| <= aleph_1 + there is a generalized Sierpinski set. 2.) The union of aleph_1 many strong measure zero sets is a strong measure zero set + there is a strong measure zero set of size aleph_2.

E. C. Marino

We present a formulation of Quantum Electrodynamics in terms of an antisymmetric tensor gauge field. In this formulation the topological current of this field appears as a source for the electromagnetic field and the topological charge therefore acts physically as an electric charge. The charged states of QED lie in the sector where the topological charge is

Shogo Tanimura

R.P. Feynman showed F.J. Dyson a proof of the Lorentz force law and the homogeneous Maxwell equations, which he obtained starting from Newton&#39;s law of motion and the commutation relations between position and velocity for a single nonrelativistic particle. We formulate both a special relativistic and a general relativistic versions of Feynman&#39;s deriv

Mark B. Wise

The chiral and heavy quark symmetries of QCD are reviewed. These symmetries are used to predict some low-momentum properties of hadrons containing a single heavy quark. (Lectures given at the CCAST Symposium on Particle Physics at the Fermi Scale May27-June4,1993)

T. G. Rizzo

The NLC may allow us to search for the `inverse&#39; process to neutrinoless double-$β$ decay, $e^-e^-\to W^-W^-$, which probes the existence of Majorana masses for neutrinos. Expectations for the observation of this process in both the Standard Model and its extension, the Left-Right Symmetric Model, are examined. (Talk given at the {\it {Workshop on Physic

Ulf-G. Meißner

I discuss the absorption and dispersion of pions in hot matter. A two-loop calculation in the framework of chiral perturbation theory is presented and its result is compactly written in terms of the two- and three-particle forward $ππ$ scattering amplitudes. At modest temperatures, $T \le 100$ MeV, the change in the pion mass is small and its dispersion law

P. Marenzoni, P. Rossi

We have performed an exhaustive search for Gribov copies on the lattice and their possible dependence from finite temperature effects. We show that, for each value of lattice size, Gribov copies are dense in configuration space at low temperature but their density tend to lower when the temperature increases. We have investigated lattice sizes running from $

J. Liu, W. X. Gao, K. Ismail, K. Y. Lee

The Aharonov-Bohm (AB) interference patterns in ring-shaped conductors are usually dominated by random features. The amplitude of the oscillations is random from sample to sample and from point to point on the magnetic field axis owing to random scattering of the electron trajectories by impurities within the wires. We report experiments on new devices made

Jian-Sheng Wang, Peter Nielaba, Vladimir Privman

Random sequential adsorption with diffusional relaxation, of two by two square objects on the two-dimensional square lattice is studied by Monte Carlo computer simulation. Asymptotically for large lattice sizes, diffusional relaxation allows the deposition process to reach full coverage. The coverage approaches the full occupation value, 1, as a power-law wi

C. Bruder, H. Schoeller

The influence of charging effects on time-dependent transport in small semiconductor quantum dots with arbitrary level spectra is studied. Starting from an explicit time-dependent tunneling Hamiltonian, a non-Markovian Master equation is derived which is also valid in the nonlinear response regime. The many-body nonequilibrium distribution functions of the d

G. M. Shimi, D. Kim, M. Y. Choi

Gardner&#39;s analysis of the optimal storage capacity of neural networks is extended to study finite-temperature effects. The typical volume of the space of interactions is calculated for strongly-diluted networks as a function of the storage ratio $α$, temperature $T$, and the tolerance parameter $m$, from which the optimal storage capacity $α_c$ is obtain

James D. Sterling, Shiyi Chen

The lattice Boltzmann equation describes the evolution of the velocity distribution function on a lattice in a manner that macroscopic fluid dynamical behavior is recovered. Although the equation is a derivative of lattice gas automata, it may be interpreted as a Lagrangian finite-difference method for the numerical simulation of the discrete-velocity Boltzm

D. Q. Lamb, C. Graziani, I. A. Smith

We have analyzed the 241 bursts for which peak counts $\C$ exist in the publicly available Burst and Transient Source Experiment (BATSE) catalog. Introducing peak counts in 1024 ms as a measure of burst brightness $\B$ and the ratio of peak counts in 64 and 1024 ms as a measure of short timescale variability $\V$, we find a statistically significant correlat

Hannu Kurki-Suonio, Pablo Laguna, Richard A. Matzner

We describe our 3-dimensional numerical relativity code for the evolution of inhomogeneous cosmologies. During the evolution the constraint equations are monitored but not solved. The code has been tested against perturbation theory with good results. We present some runs of inhomogeneous inflation with strongly inhomogeneous initial data.

J. Dai, J. F. Gunion, R. Vega

We demonstrate that expected efficiencies and purities for $b$-tagging at SSC/LHC detectors may allow detection of the Standard Model Higgs in $t\anti t \hsm$ production, with $\hsm\rta b\anti b$ decay, for $80\lsim\mhsm\lsim 130\gev$, provided $\mt\gsim 130\gev$.

Ulf H. Danielsson

In this paper the $c=1$ matrix model deformed by a $1/x^{2}$ piece is discussed. Tachyon correlation functions are calculated up to genus two using methods similar to those for the undeformed case. The possible connection with the two dimensional black hole is also considered. In particular, restrictions on naked singularities imposed by the matrix model are

Jarmo Hietarinta

In this article we present all nonsingular upper triangular solutions to the constant quantum Yang-Baxter equation $R_{j_1j_2}^{k_1k_2}R_{k_1j_3}^{l_1k_3}R_{k_2k_3}^{l_2l_3}= R_{j_2j_3}^{k_2k_3}R_{j_1k_3}^{k_1l_3}R_{k_1k_2}^{l_1l_2}$ in the three state case, i.e. all indices ranging from 1 to 3. The upper triangular ansatz implies 729 equations for 45 variab

T. Brzezinski, L. C. Papaloucas, J. Rembielinski

Quantum multiparameter deformation of real Clifford algebras is proposed. The corresponding irreducible representations are found.

B. R. Barrett, D. C. Zheng, R. J. McCarthy, J. P. Vary

A simple two-level model is developed and used to test the properties of effective interactions for performing nuclear structure calculations in truncated model spaces. It is shown that the effective many-body interactions sensitively depend on the choice of the single-particle basis and they appear to be minimized when a self- consistent Hartree-Fock basis

A. Kovner, P. S. Kurzepa

We perform the complete bosonization of 2+1 dimensional QED with one fermionic flavor in the Hamiltonian formalism. The Fermi operators are explicitly constructed in terms of the vector potential and the electric field. We carefully specify the regularization procedure involved in the definition of these operators, and calculate the fermionic bilinears and t

Hisashi Kikuchi

The chiral phase dependence of fermion partition function in spherically symmetric U(1) gauge field background is analyzed in two dimensional space-time. A well-defined method to calculated the path integral which apply to the continuous fermion spectrum is described. The one-to-one correspondence between the nonzero energy continuous spectra of two pertinen

A. M. Bincer, K. Riesselmann

We calculate the degree 2 and 6 Casimirs operators in explicit form, with the generators of G2 written in terms of the subalgebra A2