June 1994 arXiv papers — page 4

Michael Joyce

The original calculation of `spontaneous' baryogenesis overlooked the role played by transport of particles onto the bubbles wall. For typical `adiabatic' wall thicknesses and velocities one can model the problem in a fluid approximation and the mechanism is best understood as another limit of `charge transport' baryogenesis, and can produce a si

A. C. Davis, R. Brandenberger, M. Trodden

Electroweak baryogenesis has become a topic of much recent activity [1]. Here we discuss a new scenario which has the advantage of being insensitive to the order of the electroweak phase transition. We briefly review a mechanism [2] using unstable electroweak strings [3] and discuss in detail a mechanism [4] using topological defects (in particular cosmic st

Gautam Bhattacharyya, John Ellis, K. Sridhar

The vertex corrections to the leptonic partial widths of the $Z$ induced by leptoquarks that couple leptons to the top quark are considered. We obtain stringent bounds on the parameter space of the masses and Yukawa couplings of these leptoquarks, using the latest information on the $Z \rightarrow l^+l^-$ decay widths measured at LEP. Leptoquarks coupling wi

T. Barnes

Recently there has been considerable interest in the subject of molecules, which are weakly bound states of hadron pairs. The question of the existence of molecules is closely related to the more general problem of the determination of low energy hadron-hadron scattering amplitudes, which is widely believed to require nonperturbative methods. In this contrib

As. Abada

We present some results of the {\bf{ELC}} (European Lattice Collaboration) study of leptonic and semi-leptonic decays of heavy-light mesons. Results on the decay constants $f_D, f_{D_s}$ and $f_B, f_{B_s}$, the semi-leptonic form factors of $D\longrightarrow K (K^*)$ and some preliminary estimates of form factors relevant for the $B\longrightarrow π, ρ$ are

P. F. Harrison, W. G. Scott

We propose a new discrete symmetry in the generation space of the fundamental fermions, consistent with the observed fermion mass spectrum. In the case of the quarks, the symmetry leads to the unique prediction of a flat CKM matrix at high energy. We explore the possibility that evolution due to quantum corrections leads to the observed hierarchical form of

S D Bass, P V Landshoff

We discuss the small $x$ behaviour of the spin dependent structure function $g_1$. We find a contribution from the exchange of two non-perturbative gluons which behaves as $\sim ( 2 \ln {1 \over x} -1)$.

George W. S. Hou

We give a brief review of direct $CP$ violation effects in charmless $B$ decays, both at the inclusive and at the exclusive level. It is emphasized that typical exclusive final states are composed of 2--4 $K$ or $π$'s, hence particle identification (in terms of $K/π$ separation) is of crucial importance for studying $CP$ violation in these modes. Another

A. V. Kuznetsov, N. V. Mikheev

Some low-energy manifestations of a minimal extension of the Standard Model based on the quark-lepton $SU(4)_V \otimes SU(2)_L \otimes G_R$ symmetry of the Pati-Salam type are analysed. Given this symmetry a new type of mixing in the quark-lepton interactions is shown to be required. An additional arbitrariness of the mixing parameters could allow to decreas

Jizhi Wu, Richard Arnowitt, Pran Nath

The constraints on the minimal supergravity model from the b->s+γdecay are studied. A large domain in the parameter space for the model satisfies the CLEO bound, BR(b->s+γ)<5.4X10^{-4}. However, the allowed domain is expected to diminish significantly with an improved bound on this decay. The dependence of the b->s+γbranching ratio on various parameters is s

Valeri P. Frolov

A black hole considered as a part of a thermodynamical system possesses the Bekenstein-Hawking entropy $S_H =A_H /(4l_{\mbox{\scriptsize{P}}}^2)$, where $A_H$ is the area of a black hole surface and $l_{\,\mbox{\scriptsize{P}}}$ is the Planck length. Recent attempts to connect this entropy with dynamical degrees of freedom of a black hole generically did not

Chris M. Chambers, Ian G. Moss

A generalisation of Price&#39;s theorem is given for application to Inflationary Cosmologies. Namely, we show that on a Schwarzschild--de Sitter background there are no static solutions to the wave or gravitational perturbation equations for modes with angular momentum greater than their intrinsic spin.

Bjorn Jensen, Jaromír Kučera

We reinterpret the well known Taub-singularity in terms of a cylinder symmetric geometry. It is shown that a cylindrical analog to the Einstein-Rosen bridge as well as a cosmic string will be present in the geometry.

Sean A. Hayward

General laws of black-hole dynamics, some of which are analogous to the laws of thermodynamics, have recently been found for a general definition of black hole in terms of a future outer trapping horizon, a hypersurface foliated by marginal surfaces of a certain type. This theory is translated here into spin-coefficient language. Second law: the area form of

John Neergaard, Marcel den Nijs

The crossover from Edwards-Wilkinson ($s=0$) to KPZ ($s>0$) type growth is studied for the BCSOS model. We calculate the exact numerical values for the $k=0$ and $2π/N$ massgap for $N\leq 18$ using the master equation. We predict the structure of the crossover scaling function and confirm numerically that $m_0\simeq 4 (π/N)^2 [1+3u^2(s) N/(2π^2)]^{0.5}$ and

P. Coleman, E. Miranda, A. Tsvelik

We propose that the development of odd-frequency superconductivity is driven by the collective formation of neutral three body bound-states. Using a three-body bound-state ansatz we develop a mean-field theory for odd-frequency pairing within the Kondo Lattice model. Three body bound-state formation leads to the formation of a gapless band of fermions with a

A. C. C. Coolen, S. Franz

We use a linear system of Langevin spins with disordered interactions as an exactly solvable toy model to investigate a procedure, recently proposed by Coolen and Sherrington, for closing the hierarchy of macroscopic order parameter equations in disordered spin systems. The closure procedure, based on the removal of microscopic memory effects, is shown to re

Guenther Goerz, Marcus Kesseler

This paper discusses to which extent the concept of ``anytime algorithms&#39;&#39; can be applied to parsing algorithms with feature unification. We first try to give a more precise definition of what an anytime algorithm is. We arque that parsing algorithms have to be classified as contract algorithms as opposed to (truly) interruptible algorithms. With the

Martin White, Douglas Scott

There was a question raised at this meeting as to the best way to present the results of experiments measuring anisotropies in the CMB. Here we will make some simple comments about the 3 main competing methods and some suggestions. In particular we will give an over-simplified but hopefully useful method of comparing GACF numbers with other power spectra, an

Andrew Gould

I present an analytic method for estimating the errors in fitting a distribution. A well-known theorem from statistics gives the minimum variance bound (MVB) for the uncertainty in estimating a set of parameters $ł_i$, when a distribution function $F(z;ł_1 ... ł_m)$ is fit to $N$ observations of the quantity(ies) $z$. For example, a power-law distribution (o

P. Hickson, E. F. Borra, R. Cabanac, R. Content

We report the successful development and operation of a large astronomical liquid-mirror telescope. Employing a rotating 2.7-meter diameter mirror with a surface of liquid mercury, the telescope images a half-degree diameter field centered at the zenith. Located near Vancouver, British Columbia, it is equipped with a low-noise 2048x2048-pixel CCD detector, o

F. H. L. Essler, H. Frahm, A. G. Izergin, V. E. Korepin

We consider correlation functions of the spin-$\half$ XXX and XXZ Heisenberg chains in a magnetic field. Starting from the algebraic Bethe Ansatz we derive representations for various correlation functions in terms of determinants of Fredholm integral operators.

T. Banks, M. Dine

String theory, if it describes nature, is probably strongly coupled. As a result, one might despair of making any statements about the theory. In the framework of a set of clearly spelled out assumptions, we show that this is not necessarily the case. Certain discrete gauge symmetries, combined with supersymmetry, tightly constrain the form of the effective

A. Le Yaouanc, L Oliver, O. Pène, J. -C. Raynal

To start the $b$-decay session we briefly introduce and comment some important theoretical tools which are currently used in $b$ physics. Heavy Quark Symmetry and its consequences for heavy to heavy and heavy to light semi-leptonic decays, as well as for leptonic decays, are briefly summarised. It is stressed that symmetry must be completed with dynamical ca

P. M. Llatas, S. Roy

By using a bosonization we uncover the topological gravity structure of Labastida, Pernici and Witten in ordinary $2d$ gravity coupled to $(p,q)$ minimal models. We study the cohomology class associated with the fermionic charge of the topological gravity which is shown to be isomorphic to that of the total $BRST$ charge. One of the ground ring generators of

Piotr M. Hajac

A gauge invariant notion of a strong connection is presented and characterized. It is then used to justify the way in which a global curvature form is defined. Strong connections are interpreted as those that are induced from the base space of a quantum bundle. Examples of both strong and non-strong connections are provided. In particular, such connections a

G. A. Miller

Charge independence and symmetry are approximate symmetries of nature. The observations of the small symmetry breaking effects and the consequences of those effects are reviewed. The effects of the mass difference between up and down quarks and the off shell dependence $q^2$ of $ρ^0$-$ω$ mixing are stressed. In particular, I argue that models which predict a

Haskell P. Rosenthal

Structural properties are given for $D(K)$, the Banach algebra of (complex) differences of bounded semi-continuous functons on a metric space $K$. For example, it is proved that if all finite derived sets of $K$ are non-empty, then a complex function $φ$ operates on $D(K)$ (i.e., $φ\circ f\in D(K)$ for all $f\in D(K)$) if and only if $φ$ is locally Lipschitz

Matthew Miller, Rafael H. Villarreal

Assume $R$ is a polynomial ring over a field and $I$ is a homogeneous Gorenstein ideal of codimension $g\ge3$ and initial degree $p\ge2$. We prove that the number of minimal generators $ν(I_p)$ of $I$ that are in degree $p$ is bounded above by $ν_0={p+g-1\choose g-1}-{p+g-3\choose g-1}$, which is the number of minimal generators of the defining ideal of the

A. Nersessian, V. Ter-Antonian

It is shown, that in the general case the Kustaanheimo-Stiefel transformation (reduction of $4d$ oscillator on the twistor space by the Hamiltonian action of $U(1)$ with further time-reparametrization) leads to the integrable system, describing the interaction of a spinless electrically charged particle with a dyon .

A. G. Cohen, D. B. Kaplan, A. E. Nelson

We include the effects of diffusion in the electroweak spontaneous baryogenesis scenario and show that it can greatly enhance the resultant baryon density, by as much as a factor of $1/α_w^4 \sim 10^6$ over previous estimates. Furthermore, the baryon density produced is rather insensitive to parameters characterizing the first order weak phase transition, su

Kenneth Lane

Because of the top quark&#39;s very large mass, about 175~GeV, it now provides the best window into flavor physics. Thus, pair--production of top quarks at the Tevatron Collider is the best probe of this physics until the Large Hadron Collider turns on in the next century. I will discuss aspects of the mass and angular distributions that can be measured in $

M. Trodden

We investigate the region of restored electroweak symmetry around a superconducting cosmic string coupled to the Weinberg-Salam model with an extra Higgs doublet. We show that the presence of the extra Higgs fields, and in particular their CP violating relative phase, does not qualitatively affect the results of Perkins and Davis[1] obtained for the standard

D. Ghilencea, L. Micu

The amplitudes of $π$-meson decays are calculated in a relativistic nonperturbative quark model which assumes that mesons are made of a quark antiquark pair and of a scalar neutral component representing the contribution of the nonelementary fluctuations of the quark gluonic field. The experimental data can be fitted in a satisfactory manner using current qu

D. Bardin, M. Bilenky, D. Lehner, A. Olchevski

A study of the semi-analytical approach to four-fermion production in $e^+ e^-$ annihilation is presented. We classify all possible four-fermion final states and present results of new calculations for the `basic&#39; processes with the $WW,ZZ$, and $ZH$ off-shell production together with some examples of `background&#39; processes. The Initial State Radiati

Massimo Campostrini, Paolo Rossi, Ettore Vicari

Strong-coupling analysis of two-dimensional chiral models, extended to 15th order, allows for the identification of a scaling region where known continuum results are reproduced with great accuracy, and asymptotic scaling predictions are fulfilled. The properties of the large-$N$ second-order phase transition are quantitatively investigated.

M. Grabenstein, K. Pinn

We study a multigrid method for nonabelian lattice gauge theory, the time slice blocking, in two and four dimensions. For SU(2) gauge fields in two dimensions, critical slowing down is almost completely eliminated by this method. This result is in accordance with theoretical arguments based on the analysis of the scale dependence of acceptance rates for nonl

Salman Habib, Daniel E. Holz, Arkady Kheyfets, Richard A. Matzner

LAGEOS is an accurately-tracked, dense spherical satellite covered with 426 retroreflectors. The tracking accuracy is such as to yield a medium term (years to decades) inertial reference frame determined via relatively inexpensive observations. This frame is used as an adjunct to the more difficult and data intensive VLBI absolute frame measurements. There i

Arkady Kheyfets, Warner A. Miller

The classical theory of gravity predicts its own demise -- singularities. We therefore attempt to quantize gravitation, and present here a new approach to the quantization of gravity wherein the concept of time is derived by imposing the constraints as expectation-value equations over the true dynamical degrees of freedom of the gravitational field -- a repr

Vladimir G. Pestov

We show that, as conjectured by Adrien Douady back in 1972, every complete metric space is homeomorphic (moreover, isometric) to the locus of zeros of an analytic map between two Banach spaces. As a corollary, a paracompact topological space admits the structure of a Banach analytic space if and only if it is metrizable with a complete metric.

Michael Niv

Considering the speed in which humans resolve syntactic ambiguity, and the overwhelming evidence that syntactic ambiguity is resolved through selection of the analysis whose interpretation is the most `sensible&#39;, one comes to the conclusion that interpretation, hence parsing take place incrementally, just about every word. Considerations of parsimony in

Michael Niv

The complexity of a particular term-rewrite system is considered: the rule of associativity (x*y)*z --> x*(y*z). Algorithms and exact calculations are given for the longest and shortest sequences of applications of --> that result in normal form (NF). The shortest NF sequence for a term x is always n-drm(x), where n is the number of occurrences of * in x and

Michael Niv

Syntactic ambiguity abounds in natural language, yet humans have no difficulty coping with it. In fact, the process of ambiguity resolution is almost always unconscious. But it is not infallible, however, as example 1 demonstrates. 1. The horse raced past the barn fell. This sentence is perfectly grammatical, as is evident when it appears in the following co

Michael Niv

I review evidence for the claim that syntactic ambiguities are resolved on the basis of the meaning of the competing analyses, not their structure. I identify a collection of ambiguities that do not yet have a meaning-based account and propose one which is based on the interaction of discourse and grammatical function. I provide evidence for my proposal by e

S. L. Adler, G. V. Bhanot, J. D. Weckel

We study a modular neuron alternative to the McCulloch-Pitts neuron that arises naturally in analog devices in which the neuron inputs are represented as coherent oscillatory wave signals. Although the modular neuron can compute $XOR$ at the one neuron level, it is still characterized by the same Vapnik-Chervonenkis dimension as the standard neuron. We give

Fabian H. L. Essler

The {\sl dressed} Scattering matrix describing scattering of quasiparticles in various models with long-range interactions is evaluated by means of Korepin&#39;s method\upref vek1/. For models with ${1\over\sin^2(r)}$-interactions the S-matrix is found to be a momentum-independent phase, which clearly demonstrates the ideal gas character of the quasiparticle

L. Girardello, A. Giveon, M. Porrati, A. Zaffaroni

We study strong-weak coupling duality (S-duality) in N=4 supersymmetric non-Abelian Yang-Mills theories. These theories arise naturally as the low-energy limit of four-dimensional toroidal compactifications of the heterotic string. Firstly, we define the free energy in the presence of electric and magnetic fluxes using &#39;t Hooft&#39;s prescription, i.e. t

I. L. Buchbinder, I. L. Shapiro, A. G. Sibiryakov

The unified theory of string and two-dimensional quantum gravity is considered. The action for two-dimensional gravity is choosen in a well-known induced form and thus gravity posesses it&#39;s oun nontrivial dynamics even on the classical level. Three classically equivalent forms of the action of the unified theory are described, that is $D$, $D+1$ and $D+2

Tadashi Okai

Static and spherically symmetric black hole solutions with non-zero cosmological constant are investigated. A formal power series solution is found. It is proved that the number of regular horizons is less than or equal to 2 for positive cosmological constant and is less than or equal to 1 for negative cosmological constant. This shows a striking contrast to

Pankaj Jain, Arshad Momen, Joseph Schechter

Electromagnetic interactions are introduced in the effective chiral Lagrangian for heavy mesons which includes light vector particles. A suitable notion of vector meson dominance is formulated. The constraints on the heavy meson -light vector and heavy meson-light pseudoscalar coupling constants are obtained using experimental $D^* \ra D \, γ$ branching rati

R. A. M. M. Klomp, J. -L. de Kok, M. C. M. Rentmeester, Th. A. Rijken

We present results of the Nijmegen partial-wave analyses of all NN scattering data below Tlab = 500 MeV. We have been able to extract for the first time the important np phase shifts for both I = 0 and I = 1 from the np scattering data alone. This allows us to study the charge independence breaking between the pp and np I = 1 phases. In our analyses we obtai

P. Fendley, H. Saleur, N. P. Warner

We solve exactly the &#34;boundary sine-Gordon&#34; system of a massless scalar field ϕwith a \cos[βϕ/2] potential at a boundary. This model has appeared in several contexts, including tunneling between quantum-Hall edge states and in dissipative quantum mechanics. For β^2 < 8π, this system exhibits a boundary renormalization-group flow from Neumann to Diric

Sasanka Ghosh, Samir K. Paul

A nonlinear realization of super $W_{\infty}$ algebra is shown to exist through a consistent superLax formulation of super KP hierarchy. The reduction of the superLax operator gives rise to the Lax operators for $N=2$ generalized super KdV hierarchies, proposed by Inami and Kanno. The Lax equations are shown to be Hamiltonian and the associated Poisson brack

Chigak Itoi

A particular class of random walks with a spin factor on a three dimensional cubic lattice is studied. This three dimensional random walk model is a simple generalization of random walk for the two dimensional Ising model. All critical diffusion constants and associated critical exponents are calculated. Continuum field theories such as Klein-Gordon, Dirac a

V. G. Bagrov, I. L. Buchbinder, I. L. Shapiro

We construct the theoretical base for the search of the possible experimental manifestations of the torsion field at low energies. The weakrelativistic approximation to the Dirac equation in an external torsion field is considered. For the sake of generality we introduce the external electromagnetic field in parallel. The generalized (due to torsion dependen

Gordon W. Semenoff, Richard J. Szabo

We study equivariant localization formulas for phase space path integrals when the phase space is a multiply connected compact Riemann surface. We consider the Hamiltonian systems to which the localization formulas are applicable and show that the localized partition function for such systems is a topological invariant which represents the non-trivial homolo

Stephen Mrenna, G. L. Kane

We have examined how a Standard Model or Supersymmetric Higgs boson h might be detected at possible hadron colliders. The channels W(to ell nu)h(to b b~), Z(to ell ell~)h(to b b~) and W/Z(to jets)h(to tau+ tau-) are most useful. The results imply that h with mass M_h can be detected or excluded for M_h between about 80--130 GeV at any hadron collider with en

L. S. Borkowski, P. J. Hirschfeld

We discuss the effect of multichannel Kondo impurities on superconductivity. In the strong coupling regime such impurities are pairbreakers, in contrast to the ordinary Kondo effect. Measurements of $T_c$-suppression may help in identifying impurities displaying this more exotic exchange coupling to the conduction band.

M. Gasperini

I review various aspects of the pre-big-bang scenario and of its main open problems, with emphasis on the role played by the dilaton. Since the dilaton is a compelling consequence of string theory, tests of this scenario are direct tests of string theory and also, more generally, of Planck scale physics.

Luciano Rezzolla, John C. Miller

We present a new complete set of Lagrangian relativistic hydrodynamical equations describing the transfer of energy and momentum between a standard fluid and a radiation fluid in a general non-stationary spherical flow. The new set of equations has been derived for a particular application to the study of the cosmological Quark--Hadron transition but can als

C. Fransson, P. Lundqvist, R. A. Chevalier

The radio and X-ray observations of SN 1993J during the first year can be consistently explained as a result of interaction of the expanding ejecta with a circumstellar medium. The density of the circumstellar gas can be deduced from the free-free absorption of the radio emission and from the X-ray luminosity. During the first two weeks, both sets of observa

M. S. Fayache, L. Zamick

Allowing for $2$$\hbar ω$ admixtures in $^4\mbox{He}$ we find that the summed magnetic dipole isovector orbital and spin strengths are equal. This indicates a symmetry which is associated with interchanging the labels of the spin with those of the orbit. Where higher admixtures are included, the orbital sum becomes larger than the spin sum, but the sums over

Marco Frasca

We consider a massive fermion interacting with a U(1) gauge field in the limit of a large coupling constant. It is found that the current has a generalized London term that can originate massive excitations for two of the three components of the gauge field, which disappear for a free particle at rest. The origin of the superconductive term is due to a parti

Fernando Cornet, J. I. Illana

We study the sensitivity of LEP II and NLC, via two photon collisions, to the effects of anomalous $τ\overlineτ γ$ couplings. We also discuss some CP-odd observables that can be useful to disentangle the contributions from the anomalous couplings. (5 figures included via epsf appended at the end as uuencoded compressed tar postscript file).

R. J. Bursill, T. Xiang, G. A. Gehring

Using the recently developed density matrix renormalization group approach, we study the correlation function of the spin-1 chain with quadratic and biquadratic interactions. This allows us to define and calculate the periodicity of the ground state which differs markedly from that in the classical analogue. Combining our results with other studies, we predi

M. Yu. Lashkevich

It is known that 2D field theories admit several sectors of mutually local fields so as two fields from different sectors are mutually nonlocal. We show that any one-partical integrable model with ${\bf Z}_2$ symmetry contains three sectors: bosonic, fermionic and `disorder&#39; one. We generalize the form factor axioms to fermionic and `disorder&#39; sector

E. Kraus, K. Sibold

Dependence on the gauge parameters is an important issue in gauge theories: physical quantities have to be independent. Extending BRS transformations by variation of the gauge parameter into a Grassmann variable one can control gauge parameter dependence algebraically. As application we discuss the anomaly coefficient in the Slavnov-Taylor identity, $S$-matr

Edward D. Savage, G E Stedman

The applications of parabosons by Schmutz (1980) and of supersymmetry by Jarvis {\em et al.} (1984) in Jahn-Teller systems are compared and contrasted. Although a parasupersymmetric Jahn-Teller system has not yet been identified, the method of Schmutz is used here to show that the $E \times ε$ supersymmetric Jahn-Teller Hamiltonian can be written in terms of

R. A. Kraenkel, M. A. Manna, J. G. Pereira

By using the multiple scale method with the simultaneous introduction of multiple times, we study the propagation of long surface-waves in a shallow inviscid fluid. As a consequence of the requirements of scale invariance and absence of secular terms in each order of the perturbative expansion, we show that the Korteweg-de Vries hierarchy equations do appear

Mihai Horoi, Alex Brown

This document explains how to download the OXBASH code for nuclear structure calculations from the NSCL anonymous server and get it running on VAX (VMS), ALPHA (OpenVMS) and IBM RS/6000 (aix) computers. The physics behind the code is explained in the OXBASH manual, which is part of the downloading package. Everybody is welcome to download the code and use it

Alfredo Poirier

We establish necessary and sufficient conditions for the realization of mapping schemata as post-critically finite polynomials, or more generally, as post-critically finite polynomial maps from a finite union of copies of the complex numbers {\bf C} to itself which have degree two or more in each copy. As a consequence of these results we prove a transitivit

Albert Schwarz

The paper contains a short review of the theory of symplectic and contact manifolds and of the generalization of this theory to the case of supermanifolds. It is shown that this generalization can be used to obtain some important results in quantum field theory. In particular, regarding $N$-superconformal geometry as particular case of contact complex geomet

A. Barducci, R. Casalbuoni, R. Gatto, M. Modugno

We study the thermodynamics of massive Gross-Neveu models with explicitly broken discrete or continuous chiral symmetries for finite temperature and fermion densities. The large $N$ limit is discussed bearing attention to the no-go theorems for symmetry breaking in two dimensions which apply to the massless cases. The main purpose of the study is to serve as

A. Zapletal, M. Karowski

The weights are computed for the Bethe vectors of an RSOS type model with periodic boundary conditions obeying $U_q[sl(n)]$ ($q=\exp(iπ/r)$) invariance. They are shown to be highest weight vectors. The q-dimensions of the corresponding irreducible representations are obtained.

Demosthenes Ellinas, Jan Sobczyk

We show that the quantum Heisenberg group $H_{q}(1)$ can be obtained by means of contraction from quantum $SU_q(2)$ group. Its dual Hopf algebra is the quantum Heisenberg algebra $U_{q}(h(1))$. We derive left and right regular representations for $U_{q}(h(1))$ as acting on its dual $H_{q}(1)$. Imposing conditions on the right representation the left represen

A. Balinsky

New algebraic structure on the orbits of dressing transformations of the quasitriangular Poisson Lie groups is provided. This give the topological interpretation of the link invariants associated with the Weinstein--Xu classical solutions of the quantum Yang-Baxter equation. Some applications to the three-dimensional topological quantum field theories are di

H. Awata, M. Fukuma, Y. Matsuo, S. Odake

We propose a series of new subalgebras of the $W_{1+\infty}$ algebra parametrized by polynomials $p(w)$, and study their quasifinite representations. We also investigate the relation between such subalgebras and the $\hat{\mbox{gl}}(\infty)$ algebra. As an example, we investigate the $\Win$ algebra which corresponds to the case $p(w)=w$, presenting its free

Giampiero Passarino

The status of the theoretical uncertainties for LEP1 observables associated with the corresponding comparison among different codes is briefly reviewed.

R. Aleksan, A. Le Yaouanc, L. Oliver, O. Pène

The heavy to light form factors in $B$ decays are discussed. Critical discussion of theoretical approaches is made with special emphasis on their failure to describe the $B \to K^{(\ast )}ψ$ data.

Stuart Raby

In this talk~\footnote{Talk presented at the IFT Workshop on Yukawa Couplings, Gainesville, FL, February 1994.} I summarize published work on a systematic operator analysis for fermion masses in a class of effective supersymmetric SO(10) GUTs \cite{adhrs}~\footnote{This work is in collaboration with G. Anderson, S. Dimopoulos, L.J. Hall, and G. Starkman.}. G

A. Yu. Dubin, Yu. S. Kalashnikova

The average of two Wilson loops is expressed in terms of gauge invariant field strength correlators. Assuming the existence of finite correlation length $T_g$ and taking into account the absence of a fixed direction in colour space, we generalize the area law asymptotics for the case of the average of two Wilson loops embedded into the same plane. The result

F. Karsch, T. Neuhaus, A. Patkos

We investigate an effective model for the finite temperature restoration phase transition of the electroweak theory. It is obtained by dimensional reduction of the $3+1$ dimensional full theory and by subsequent integration over all static gauge degrees of freedom. The resulting theory corresponds to a $3$-dimensional $O(4)$ ferromagnet containing cubic and

V. N. Melnikov, M. Yu. Konstantinov

The evolution of 4-dimensional and (4+d)-dimensional (d=1,2) cosmological models based on the integrable Weyl geometry are considered numerically both for empty space-time and for scalar field with non minimal coupling with gravity.

John T. Whelan

One of the reasons we expect a standard quantum mechanics, which predicts probabilities for alternatives defined on spacelike slices, to be inadequate for quantum gravity is that the notion of ``spacelike&#39;&#39; is ill-defined in a theory where the metric itself is behaving quantum-mechanically. Spacetime coarse grainings--sets of alternatives defined wit

Huw Price

Bell&#39;s Theorem assumes that hidden variables are not influenced by future measurement settings. The assumption has sometimes been questioned, but the suggestion has been thought outlandish, even by the taxed standards of the discipline. (Bell thought that it led to fatalism.) The case for this reaction turns out to be surprisingly weak, however. We show

Enrique Diez, Angel Sanchez, Francisco Dominguez-Adame

We study how the influence of structural correlations in disordered systems manifests itself in experimentally measurable magnitudes, focusing on dc conductance of semiconductor superlattices with general potential profiles. We show that the existence of bands of extended states in these structures gives rise to very noticeable peaks in the finite temperatur

C. Hiergeist, M. Lassig, R. Lipowsky

Bundles of strings which interact via short-ranged pair potentials are studied in two dimensions. The corresponding transfer matrix problem is solved analytically for arbitrary string number N by Bethe ansatz methods. Bundles consisting of N identical strings exhibit a unique unbinding transition. If the string bundle interacts with a hard wall, the bundle m

Tsutomu Momoi

We study the spin-wave spectrum of the Heisenberg antiferromagnet on a bipartite lattice. The spin-wave spectrum on a Néel-ordered ground state is bounded as $\varepsilon (k) \le c |k| $, where $c$ gives an upper bound for the spin-wave velocity. In the large-$S$ limit, the upper bound $c$ coincides with the result of the spin-wave theory.

T Xiang, J M Wheatley

The quasiparticle density of states (DOS), the energy gap, the superfluid density $ρ_s$, and the localization effect in the s- and d-wave superconductors with non-magnetic impurity in two dimensions (2D) are studied numerically. For strong (unitary) scatters, we find that it is the range of the scattering potential rather than the symmetry of the superconduc

Enzo Marinari, Giorgio Parisi, Felix Ritort

We introduce and study a model which admits a complex landscape without containing quenched disorder. Continuing our previous investigation we introduce a disordered model which allows us to reconstruct all the main features of the original phase diagram, including a low $T$ spin glass phase and a complex dynamical behavior.

K. Penc, F. Mila

We propose a quantitative estimate of the charge gap that opens in the one-dimensional dimerized Hubbard model at quarter-filling due to dimerization, which makes the system effectively half--filled, and to repulsion, which induces umklapp scattering processes. Our estimate is expected to be valid for any value of the repulsion and of the parameter describin

M. T. Batchelor, C. M. Yung

We perform a systematic exact algebraic search for integrable spin-S chains which are isotropic in spin space, i.e. are su(2)-invariant. The families of spin chains found for S < 14 support recent arguments in favour of the complete classification of all such integrable chains. The integrable families of spin chains are discussed in the light of the conjectu

Joerg P. Ueberla

In many current speech recognizers, a statistical language model is used to indicate how likely it is that a certain word will be spoken next, given the words recognized so far. How can statistical language models be improved so that more complex speech recognition tasks can be tackled? Since the knowledge of the weaknesses of any theory often makes improvin

David Israel

&#34;Natural languages are programming languages for minds.&#34; Can we or should we take this slogan seriously? If so, how? Can answers be found by looking at the various &#34;dynamic&#34; treatments of natural language developed over the last decade or so, mostly in response to problems associated with donkey anaphora? In Dynamic Logic of Programs, the mea

Per Dahlqvist

We address the problems in applying cycle expansions to bound chaotic systems, caused by e.g. intermittency and incompleteness of the symbolic dynamics. We discuss zeta functions associated with weighted evolution operators and in particular a one-parameter family of weights relevant for the calculation of classical resonance spectra, semiclassical spectra a

Richard P. Nelson, John C. B. Papaloizou

We present a new formulation of the equations of motion used in smoothed particle hydrodynamics (SPH). The spatial resolution in SPH is determined by the smoothing length, $h$, and it has become common practice for each particle to be given its own adaptive smoothing length, $h_i$. Consequently, the dynamic range that may be spatially resolved is greatly inc

T. J. Broadhurst, A. N. Taylor, J. A. Peacock

We present a new method for measuring the projected mass distributions of galaxy clusters. The gravitational amplification is measured by comparing the joint distribution in redshift and magnitude of galaxies behind the cluster with that of field galaxies. We show that the total amplification is directly related to the surface mass density in the weak field

Q. Bo, X. P. Wu, Z. L. Zou

The deflection angle $Δϕ$ of light rays by the gravitational field of a spherical system $M(r)$ is calculated using the MOdified Newtonian Dynamics (MOND). It is shown that $Δϕ$ with an impact parameter $r_0$ can be expressed by the measured rotation velocity $v(r)$ as $Δϕ(r_0)=2\int_{r_0}^{\infty} \frac{v^2(r)}{c^2}\frac{r_0dr}{r\sqrt{r^2-r_0^2}}$, where $v

Uros Seljak

We present a simple, yet accurate approximation for calculating the cosmic microwave background anisotropy power spectrum in adiabatic models. It consists of solving for the evolution of a two-fluid model until the epoch of recombination and then integrating over the sources to obtain the CMB anisotropy power spectrum. The approximation is useful both for a

Charles H. Walter

A subscheme $X\subset \Bbb P^{n+3}$ of codimension $3$ is {\em Pfaffian} if it is the degeneracy locus of a skew-symmetric map $f:\cal{E}\spcheck(-t) @>>> \cal{E}$ with $\cal{E}$ a locally free sheaf of odd rank on $\Bbb P^{n+3}$. It is shown that a codimension $3$ subscheme $X\subset\Bbb P^{n+3}$ is Pfaffian if and only if it is locally Gorenstein, subcanon