arXiv papers from April 1994

Lajos Diósi

Standard methods of the theory of permanent state reduction are shown to offer an alternative realization of Omn\`es' project. Our proposal, as simple as Omn\`es' one, possesses closed master equation for the ensemble density operator, assuring causality.

Jonathan M. Evans

We consider ways in which conventional supersymmetry can be embedded in the set of more general fermionic transformations proposed recently [\Ref{B}] as a framework in which to study $d=10$ super Yang-Mills. Solutions are exhibited which involve closed algebras of various numbers of supersymmetries together with their invariance groups: nine supersymmetries

Bao-An Li

Within a hadronic transport model we study in detail contributions to kaon yields and momentum spectra from various baryon (resonance)-baryon (resonance) and $\pi N$ interactions in heavy-ion collisions at beam energies near the free-space kaon production threshold. It is found that the finite lifetime of baryon resonances affects significantly the shape of

Bao-An Li, Dieter H. Gross, Volker Lips, Helmut Oeschler

The excitation energy and the nuclear density at the time of breakup are extracted for the $\alpha + ^{197}Au$ reaction at beam energies of 1 and 3.6 GeV/nucleon. These quantities are calculated from the average relative velocity of intermediate mass fragments (IMF) at large correlation angles as a function of the multiplicity of IMFs using a statistical mod

Bao-An Li, Che Ming Ko, Guoqiang Li

We study the effects of $N^{*}(1440)$ resonance on the production of kaons, antikaons and antiprotons in heavy-ion collisions at subthreshold energies. Using free-space widths for the $\Delta(1232)$ and the $N^{*}(1440)$ resonance and free-space thresholds for particle production, it is found that the $N^{*}$-baryon interactions contribute about 10\%, 25\% a

H. Itoyama, M. Koike

We discuss multicritical behavior of $c=1$ matrix model, extending the recent work of ref. \cite{CIO} on a nonperturbative completion of the density of states function. For the odd orders of multicriticality, we are able to determine the higher genus contributions and a nonperturbative completion from the WKB wave function of the multicritical periodic poten

A. L. Roy, R. P. Norris, M. J. Kesteven, E. R. Troup

We have observed a sample of 157 Seyfert galaxies with a 275 km baseline radio interferometer to search for compact, high brightness temperature radio emission from the active nucleus. We obtain the surprising result that compact radio cores are much more common in Seyfert 2 than in Seyfert 1 galaxies, which at first seems to be inconsistent with orientation

A. Fring, R. Koberle

We demonstrate that the generalization of the Coleman-Thun mechanism may be applied to the situation, when considering scattering processes in 1+1-dimensions in the presence of reflecting boundaries. For affine Toda field theories we find that the binding energies of the bound states are always half the sum over a set of masses having the same colour with re

R. M. Noack, S. R. White, D. J. Scalapino

We discuss techniques of the density matrix renormalization group and their application to interacting fermion systems in more than one dimension. We show numerical results for equal--time spin--spin and singlet pair field correlation functions, as well as the spin gap for the Hubbard model on two chains. The system is a gapped spin liquid at half--filling a

A. O. Barvinsky, A. Yu. Kamenshchik

The quantum gravitational scale of inflation is calculated by finding a sharp probability peak in the distribution function of chaotic inflationary cosmologies driven by a scalar field with large negative constant $\xi$ of nonminimal interaction. In the case of the no-boundary state of the universe this peak corresponds to the eternal inflation, while for th

A. O. Barvinsky, Yu. V. Gusev, G. A. Vilkovisky, V. V. Zhytnikov

The one-loop effective action for a generic set of quantum fields is calculared as a nonlocal expansion in powers of the curvatures (field strengths). This expansion is obtained to third order in the curvature. It is stressed that the covariant vertices are finite. The trace anomaly in four dimensions is obtained directly by varying the effective action. The

Fred Cooper, Yuval Kluger, Emil Mottola, Juan Pablo Paz

The nonequilibrium dynamics of the chiral phase transition expected during the expansion of the quark-qluon plasma produced in a high energy hadron or heavy ion collision is studied in the O(4) linear sigma model to leading order in a large $N$ expansion. Starting from an approximate equilibrium configuration at an initial proper time $\tau$ in the disordere

A. O. Barvinsky, Yu. V. Gusev, G. A. Vilkovisky, V. V. Zhytnikov

The trace of the heat kernel is expanded in a basis of nonlocal curvature invariants of $N$th order. The coefficients of this expansion (the nonlocal form factors) are calculated to third order in the curvature inclusive. The early-time and late-time asymptotic behaviours of the trace of the heat kernel are presented with this accuracy. The late-time behavio

A. O. Barvinsky, Yu. V. Gusev, G. A. Vilkovisky, V. V. Zhytnikov

A complete basis of nonlocal invariants in quantum gravity theory is built to third order in spacetime curvature and matter-field strengths. The nonlocal identities are obtained which reduce this basis for manifolds with dimensionality $2\omega<6$. The present results are used in heat-kernel theory, theory of gauge fields and serve as a basis for the model-i

Joseph I. Kapusta, Ajit M. Srivastava

We investigate the production of baryons and antibaryons in the central rapidity region of high energy nuclear collisions within the framework of the Skyrme model taking into account the effects of explicit chiral symmetry breaking. We argue that the formation of disordered chiral condensates may lead to enhanced baryon-antibaryon production at low transvers

S. Sethi

By providing a general correspondence between Landau-Ginzburg orbifolds and non-linear sigma models, we find that the elusive mirror of a rigid manifold is actually a supermanifold. We also discuss when sigma models with super-target spaces are conformally invariant and describe their chiral rings. Both supermanifolds with and without Kahler moduli are consi

Scott Pratt, Wolfgang Bauer

The ability of semi-classical transport models to correctly simulate Pauli blocking and Bose enhancement is discussed. In the context of simple quantum mechanical systems, it is shown that using $(1 \pm f)$ enhancements is inadequate to describe systems far from equilibrium. The relaxation of $(1 + f)$ descriptions toward equilibrium is studied both in the c

Anupam Singh

Recent observations of the space distribution of quasars indicate a very notable peak in space density at a redshift of $2$ to $3$.It is pointed out in this article that this may be the result of a phase transition which has a critical temperature of roughly a few meV (in the cosmological units h=c=k=1 ). It is further pointed out that such a phase transitio

M. A. Moore, N. K. Wilkin

Starting from the Ginzburg-Landau free energy of a type II superconductor in a magnetic field we estimate the energy associated with two vortices crossing. The calculations are performed by assuming that we are in a part of the phase diagram where the lowest Landau level approximation is valid. We consider only two vortices but with two markedly different se

R. Rueckl, A. Vogt

We study the effects of light gluinos with mass below about 1 GeV on the nucleon parton densities and the running of alpha_(S). It is shown that from the available high-statistics DIS data no lower bound on the gluino mass can be derived. Also in the new kinematical region accessible at HERA the influence of such light gluinos on structure f unctions is foun

Adam Frank, Garrelt Mellema

We present the results of two-dimensional radiation-gasdynamic simulations of aspherical Planetary Nebulae (PNe) evolution. These simulations were constructed using the Generalized Interacting Stellar Winds (GISW) scenario of Balick (1987) where a fast, tenuous wind from the central star expands into a toroidal, slow, dense wind. We demonstrate that the GISW

Terry Gannon

The SU(3) modular invariant partition functions were first completely classified in Ref.\ \SU. The purpose of these notes is four-fold: \item{(i)} Here we accomplish the SU(3) classification using only the most basic facts: modular invariance; $M_{\la\mu}\in{\bf Z}_{\ge}$; and $M_{00}=1$. In \SU{} we made use of less elementary results from Moore-Seiberg, in

Anjan S. Joshipura

Various hints on the neutrino masses namely, ({\em i}) the solar neutrino deficit ({\em ii}) the atmospheric neutrino deficit ({\em iii}) the need for the dark matter and/or ({\em iv}) the non-zero neutrinoless double beta decay collectively imply that all the three neutrinos must be nearlty degenerate. This feature can be understood in the left right symmet

Amit Giveon, Edward Witten

It is shown that in string theory mirror duality is a gauge symmetry (a Weyl transformation) in the moduli space of $N=2$ backgrounds on group manifolds, and we conjecture on the possible generalization to other backgrounds, such as Calabi-Yau manifolds.

M. V. Altaisky, V. A. Bednyakov, S. G. Kovalenko

It is argued that large-scale ($>7^o$) cosmic microwave background anisotropy detected in COBE cosmic experiment can be considered as a trace of the quantum gravity fractal structure.

G. Cattapan, L. Canton

In order to approach the pion--multinucleon problem, we have found it convenient to reformulate the general N--body theory starting from the fully unclusterized (i.e., N <- N) amplitude. If we rewrite such an amplitude in terms of new unknowns which can be later identified as the amplitudes for all the (N-1) <- (N-1) cluster processes, and repeat recursively

T. A. Costi, P. Schmitteckert, J. Kroha, P. Woelfle

We use the numerical renormalization group to calculate the auxiliary spectral functions of the $U=\infty$ Anderson impurity model. The slave--boson and pseudo--fermion spectral functions diverge at the threshold with exponents $\alpha_{b}$ and $\alpha_{f}$ given in terms of the conduction electron phase shifts by the X--ray photoemission and the X--ray abso

B. Moussallam, J. Stern

Electromagnetic decays of the scalar mesons are shown to be constrained by chiral symmetry as a consequence of the fact that, in the chiral limit, the two and three-point functions $<SS-PP>$ and $<VVS>$ satisfy super-convergent dispersion relations. The QCD asymptotic behavior of the latter is canonical and it can be saturated by a finite number of resonance

S. Deser, A. Schwimmer

The problem of maintaining scale and conformal invariance in Maxwell and general N-form gauge theories away from their critical dimension d=2(N+1) is analyzed.We first exhibit the underlying group-theoretical clash between locality,gauge,Lorentz and conformal invariance require- ments. "Improved" traceless stress tensors are then constructed;each violates on

M. V. N. Murthy, R. Shankar

We show that the particles in the Calogero-Sutherland Model obey fractional exclusion statistics as defined by Haldane. We construct anyon number densities and derive the energy distribution function. We show that the partition function factorizes in the form characteristic of an ideal gas. The virial expansion is exactly computable and interestingly it is o

Jacek Dziarmaga

We present two examples of parity-invariant $[U(1)]^{2}$ Chern-Simons-Higgs models with spontaneously broken symmetry. The models possess topological vortex excitations. It is argued that the smallest possible flux quanta are composites of one quantum of each type $(1,1)$. These hybrid anyons will dominate the statistical properties near the ground state. We

P. Cea, L. Cosmai

We study the distribution of the color fields due to a static quark-antiquark pair in SU(2) lattice gauge theory. We find that the London penetration length measured after Abelian projection in the Abelian Covariant gauge (Maximal Abelian gauge) agrees with the one obtained without gauge fixing. Moreover the penetration length scales according to asymptotic

Y. M. Ahn, B. K. Chung, J. -M. Chung, Q-Han Park

A new aspect of the vacuum structure of 2+1-dimensional Thirring model is presented. Using the Fierz identity, we split the current-current four-Fermi interaction in terms of a matrix valued auxiliary scalar field and compute its effective potential. Energy consideration shows that contrary to earlier expectations, parity in general is spontaneously broken a

M. Hasenbusch, M. Marcu, K. Pinn

We confirm the Kosterlitz-Thouless scenario of the roughening transition for three different Solid-On-Solid models: the Discrete Gaussian model, the Absolute-Value-Solid-On-Solid model and the dual transform of the XY model with standard (cosine) action. The method is based on a matching of the renormalization group flow of the candidate models with the flow

C. Schmidhuber, A. A. Tseytlin

Time-dependent solutions of bosonic string theory resemble renormalisation group trajectories in the space of 2d field theories: they often interpolate between repulsive and attractive static solutions. It is shown that the attractive static solutions are those whose spatial sections are minima of |\bar c-25|, where \bar c is the `c-function'. The size of th

Wen-Jui Huang, J. C. Shaw, H. C. Yen

We study the supersymmetric Gelfand-Dickey algebras associated with the superpseudodifferential operators of positive as well as negative leading order. We show that, upon the usual constraint, these algebras contain the N=2 super Virasoro algebra as a subalgebra as long as the leading order is odd. The decompositions of the coefficient functions into N=1 pr

Gordon Chalmers

We show that general cutoff scalar field theories in four dimensions are perturbatively renormalizable through the use of diagrammatic techniques and an adapted BPH renormalization method. Weinberg's convergence theorem is used to show that operators in the Lagrangian with dimension greater than four, which are divided by powers of the cutoff, produce pertur

Dongsu Ryu, T. W. Jones

We describe a numerical code to solve the equations for ideal magnetohydrodynamics (MHD). It is based on an explicit finite difference scheme on an Eulerian grid, called the Total Variation Diminishing (TVD) scheme, which is a second-order-accurate extension of the Roe-type upwind scheme. We also describe a nonlinear Riemann solver for ideal MHD, which inclu

Adam Frank, T. W. Jones, Dongsu Ryu

Using a new, second-order accurate numerical method we present dynamical simulations of oblique MHD cosmic ray (CR) modified plane shock evolution using the two-fluid model for diffusive particle acceleration. The numerical shocks evolve to published analytical steady state properties. In order to probe the dynamical role of magnetic fields we have explored

E. H. Lieb, J. P. Solovej, J. Yngvason

Atomic-like systems in which electronic motion is two dimensional are now realizable as ``quantum dots&#39;&#39;. In place of the attraction of a nucleus there is a confining potential, usually assumed to be quadratic. Additionally, a perpendicular magnetic field $B$ may be present. We review some recent rigorous results for these systems. We have shown that

Marc Kamionkowski

I discuss contributions to the diffuse gamma-ray background from decay and annihilation of weakly interacting massive particles (WIMPs). I first review the calculation of the cosmological abundance of a WIMP and show that it is simply related to the cross section for annihilation of the WIMP into lighter particles. The diffuse extragalactic background radiat

Daniel I. Fivel

An ambiguity is pointed out in J.S. Bell's argument that the distinction between quantum mechanics and hidden variable theories cannot be found in the behavior of single-particle beams. Within the context of theories for which states are unambiguously defined it is shown that the question of whether quantum mechanics or a locally realistic theory is valid ma

S. A. Abel, C. M. A. Scheich

We present a classification of (2,2) free field compactifations with one twist in which only 95 distinct models (generations and antigenerations) are found. Models with three generations and no antigenerations are given.

Y. C. Chen, T. K. Lee

The initial trial wave function used in a simple ground-state projection method, the power method, is systematically improved by using Lanczos algorithm. Much faster convergence to the ground state achieved by using these wave functions significantly reduces the effect of the fermion sign problem. The energy, spin and charge correlation functions are calcula

John J. Neumann, George Fai

A classical Lagrangian model of the Pauli potential is introduced. It is shown that the kinematic kinetic energy ($\sum \frac{1}{2} m v^2$) in the model approximately reproduces the energy of a free Fermi gas at low temperatures and at densities relevant in nuclear collisions with moderate beam energies. Differences between canonical and kinematic quantities

D. V. Khveshchenko

We demonstrate that the exact form-factors of the Calogero-Sutherland model which were recently found in Ref.[10] in confirmation of the congectures earlier made by Haldane (Ref.[9]) can be reproduced in the framework of some bosonization procedure in momentum space. This observation implies a possibility of an exact bosonization of this model describing one

Michel Dubois-Violette, Thierry Masson

We define a new cohomology for associative algebras which we compute for algebras with units.

R. Loll, J. M. Mourao, J. N. Tavares

We study the suitability of complex Wilson loop variables as (generalized) coordinates on the physical phase space of $SU(2)$-Yang-Mills theory. To this end, we construct a natural one-to-one map from the physical phase space of the Yang-Mills theory with compact gauge group $G$ to a subspace of the physical configuration space of the complex $G^\C$-Yang-Mil

W. Taylor

Several string theories related to QCD in two dimensions are studied. For each of these theories the large $N$ free energy on a (target) sphere of area $A$ is calculated. By considering theories with different subsets of the geometrical structures involved in the full QCD${}_2$ string theory, the different contributions of these structures to the string free

S. R. Slabospitsky

The $B_c$--meson production cross section was calculated in the perturbative QCD. Various distributions of the charged leptons from the $B_c \to l \nu J/\psi(\to l^+ l^-)$ decay were obtained. The $B_c$--meson mass measurement from such decays is also discussed.

Keith A. Olive

An overview of baryogenesis in the early Universe is presented. The standard big bang model including big bang nucleosynthesis and inflation is breifly reviewed. Three basic models for baryogenesis will be developed: The ``standard" out-of-equilibrium decay model; the decay of scalar consensates along flat directions in supersymmetric models; and lepto-baryo

Bjørn Jensen

Aspects of the thermo-dynamics of a black hole which is either pierced by a cosmic gauge string or contains a global monopole are investigated. We also make some comments on the physical significance of the fact that the gravitational mass carried by a global monopole is negative. We note in particular that the negative monopole mass implies a gravitational

L. D. Faddeev, G. P. Korchemsky

We show that the one-dimensional lattice model proposed by Lipatov to describe the high energy scattering of hadrons in multicolor QCD is completely integrable. We identify this model as the XXX Heisenberg chain of noncompact spin $s=0$ and find the conservation laws of the model. A generalized Bethe ansatz is developed for the diagonalization of the hamilto

Rodolfo Gambini, Alcides Garat, Jorge Pullin

We study the algebra of constraints of quantum gravity in the loop representation based on Ashtekar's new variables. We show by direct computation that the quantum commutator algebra reproduces the classical Poisson bracket one, in the limit in which regulators are removed. The calculation illustrates the use of several computational techniques for the loop

Kyungsik Kang

The elastic hadron-hadron scattering at high energies is one of the most fundamental subjects of all particle physics problems and yet is least understood in spite of many advances in quantum chromodynamics (QCD) at the conceptual level. We review here the recent theoretical and experimental status of the subject as well as the rigorous results of the high e

M. G. Harris, J. F. Wheater

We study a model in which p independent Ising spins are coupled to 2d quantum gravity (in the form of dynamical planar phi-cubed graphs). Consideration is given to the p tends to infinity limit in which the partition function becomes dominated by certain graphs; we identify most of these graphs. A truncated model is solved exactly providing information about

Michele Maggiore

We describe the horizon of a quantum black hole in terms of a dynamical surface which defines the boundary of space-time as seen by external static observers, and we define a path integral in the presence of this dynamical boundary. Using renormalization group arguments, we find that the dynamics of the horizon is governed by the action of the relativistic b

D. Poilblanc, D. J. Scalapino, W. Hanke

The effect of a magnetic (S=1/2) impurity coupled to a 2D system of correlated electrons (described by the t--J model) is studied by exact diagonalisations. It is found that, if the exchange coupling of the impurity with the neighboring spins is ferromagnetic or weakly antiferromagnetic, an extra hole can form bound states of different spatial symmetries wit

Hiroshi Shiba, Tsuneo Suzuki

Monopole and photon contributions to abelian Wilson loops are calculated using Monte-Carlo simulations of SU(2) QCD in the maximally abelian gauge. The string tension is well reproduced only by monopole contributions, whereas photons alone are responsible for the Coulomb coefficient of the abelian static potential.

Tal Alexander, Hagai Netzer

The Bloated Stars Scenario proposes that AGN broad line emission originates in the winds or envelopes of bloated stars (BS). Its main advantage over BLR cloud models is the gravitational confinement of the gas and its major difficulty the large estimated number of BSs and resulting high mass loss rate. We calculate the emission line spectrum by a detailed nu

G. K. Leontaris, J. D. Vergados

A new more rigorous and accurate method for treating neutrino oscillations in the context of the MSW effect in a medium is proposed. This leads to a new type of resonance condition which for small mixing angles puts rather stringent conditions on $E_{\nu}/\delta {m^2}$. The implications on the solar neutrino problem are discussed.

Gertjan van Noord, Gosse Bouma

The standard HPSG analysis of Germanic verb clusters can not explain the observed narrow-scope readings of adjuncts in such verb clusters. We present an extension of the HPSG analysis that accounts for the systematic ambiguity of the scope of adjuncts in verb cluster constructions, by treating adjuncts as members of the subcat list. The extension uses powerf

Toru Goto, Takeshi Nihei, Jiro Arafune

Flavor mixing in the quark-squark-gluino coupling is studied for the minimal SU(5) SUGRA-GUT model and applied to evaluation of the nucleon lifetime. All off-diagonal (generation mixing) elements of Yukawa coupling matrices and of squark/slepton mass matrices are included in solving numerically one-loop renormalization group equations for MSSM parameters, an

L. L. Kiang, T. -S. H. Lee, D. O. Riska

It is shown that a satisfactory explanation of the ratio of the rates of the reactions $^3He(\pi^-,nn)$ and $^3He(\pi^-,np)$ for stopped pions is obtained once the effect of the short range two-nucleon components of the axial charge operator for the nuclear system is taken into account. By employing realistic models for the nucleon-nucleon interaction in the

T. Aida, Y. Kitazawa, H. Kawai, M. Ninomiya

We study quantum gravity in $2+\epsilon$ dimensions in such a way to preserve the volume preserving diffeomorphism invariance. In such a formulation, we prove the following trinity: the general covariance, the conformal invariance and the renormalization group flow to Einstein theory at long distance. We emphasize that the consistent and macroscopic universe

A Donnachie, P V Landshoff

Soft pomeron exchange at high energy includes minijet production at central rapidity values. This predicts copious production of minijets in deep inelastic scattering at small $x$, which is closely related to the fact that $\nu W_2$ exhibits Regge behaviour. It helps to explain also how the integrated inclusive cross-section for minijet production in $\gamma

Holger Frahm, Alexander R. Its, Vladimir E. Korepin

We consider the probability to find a string of $x$ adjacent parallel spins in the antiferromagnetic ground state of the model (in a magnetic field). We derive a system of integro-difference equations which define this probability. This system is completely integrable, it has Lax representation and a corresponding Riemann-Hilbert problem. The quantum correla

Yang Xian

The spontaneous dimerization of the frustrated spin-$1\over2$ antiferromagnetic chains is studied by a microscopic approach based on a proper set of composite operators (i.e., pseudo-spin operators). Two approximation schemes are developed. Firstly, a spin-wave approximation is made by a Dyson-Mal\'eev-like boson transformation. The ground-state properties a

S. Massar, R. Parentani

The vacuum fluctuations that induce the transitions and the thermalisation of a uniformly accelerated two level atom are studied in detail. Their energy content is revealed through the weak measurement formalism of Aharonov et al. It is shown that each time the detector makes a transition it radiates a Minkowski photon. The same analysis is then applied to t

R. Mohayaee, C. N. Pope, K. S. Stelle, K. W. Xu

We reformulate the BRST quantisation of chiral Virasoro and $W_3$ worldsheet gravities. Our approach follows directly the classic BRST formulation of Yang-Mills theory in employing a derivative gauge condition instead of the conventional conformal gauge condition, supplemented by an introduction of momenta in order to put the ghost action back into first-ord

B. Dey, C. N. Kumar

Given a kink bearing Hamiltonian, Isospectral Hamiltonian approach is used in generating new sets of Hamiltonains which also admit kink solutions. We use Sine-Gordon model as a example and explicitly work out the new sets of potentials and the solutions.

A. C. Clapp, M. J. Devlin, J. O. Gundersen, C. A. Hagmann

We present results from two four-frequency observations centered near the stars Sigma Hercules and Iota Draconis during the fourth flight of the Millimeter-wave Anisotropy eXperiment (MAX). The observations were made of 6 x 0.6-degree strips of the sky with 1.4-degree peak to peak sinusoidal chop in all bands. The FWHM beam sizes were 0.55+/-0.05 degrees at

Lisa C. Jeffrey

Let $G$ be a compact connected semisimple Lie group. We extend the techniques of Weinstein [W] to give a construction in group cohomology of symplectic forms $\omega$ on \lq twisted' moduli spaces of representations of the fundamental group $\pi$ of a 2-manifold $\Sigma$ (the smooth analogues of ${\rm Hom} (\pi_1(\Sigma), G)/G$) and on relative character var

Lisa C. Jeffrey

We use group cohomology and the de Rham complex on simplicial manifolds to give explicit differential forms representing generators of the cohomology rings of moduli spaces of representations of fundamental groups of 2-manifolds. These generators are constructed using the de Rham representatives for the cohomology of classifying spaces $BK$ where $K$ is a co

A. Mastichiadis, R. J. Protheroe, A. P. Szabo

We calculate the spectrum of photons resulting from electromagnetic cascades through thermal radiation, and examine the consequences of including triplet production in these cascades. We assume that the cascade is one-dimensional, and we find that this approximation is justified in the present work for thermal radiation with temperature less than $10^{-3} mc

M. Chertkov, I. Kolokolov

The transverse spin autocorrelation function at an arbitrary temperature are calculated rigorously for the system of $N$ uniformly exchanged quantum spins. At large $N$ the correlator in the para-phase is found to have a Gaussian bump at small times and a non vanishing tail at large times. A possible application of those exact results as forming a starting d

Boro Grubisic

The asymptotic behavior of geometry near the boundary of maximal Cauchy development is studied using a perturbative method, which at the zeroth order reduces Einstein's equations to an exactly solvable set of equations---Einstein's equations with all ``space" derivatives dropped. The perturbative equations are solved to an {\em arbitrarily-high order} for th

Ricardo Doldan, Pablo Mora, Rodolfo Gambini

We analyze the quantization of dynamical systems that do not involve any background notion of space and time. We give a set of conditions for the introduction of an intrinsic time in quantum mechanics. We show that these conditions are a generalization of the usual procedure of deparametrization of relational theories with hamiltonian constraint that allow t

The SLD Collaboration

We present a precise measurement of the left-right cross section asymmetry ($A_{LR}$) for $Z$ boson production by $\ee$ collisions. The measurement was performed at a center-of-mass energy of 91.26 GeV with the SLD detector at the SLAC Linear Collider (SLC). The luminosity-weighted average polarization of the SLC electron beam was (63.0$\pm$1.1)%. Using a sa

Mary Dalrymple, John Lamping, Fernando Pereira, Vijay Saraswat

We present an analysis of the semantic interpretation of intensional verbs such as seek that allows them to take direct objects of either individual or quantifier type, producing both de dicto and de re readings in the quantifier case, all without needing to stipulate type-raising or quantifying-in rules. This simple account follows directly from our use of

Yuji Kodama

The normal form for a system of ode's is constructed from its polynomial symmetries of the linear part of the system, which is assumed to be semi-simple. The symmetries are shown to have a simple structure such as invariant function times symmetries of degree one called basic symmetries. We also show that the set of symmetries naturally forms an infinite dim

A. A. Balinsky

Topological interpretation of the link invariants associated with the Weinstein--Xu classical solutions of the quantum Yang-Baxter equation are provided.

M. A. P. Martins

We attempt to a physical interpretation of some known static vacuum solutions of Einstein's equations, namely, the A and B metrics of Ehlers and Kundt. All of them have axial symmetry, so they can be transformed to the Weyl form. In Weyl coordinates $\ln\sqrt{-g_{44}}$ obeys a Laplace equation, and from this a source, called The Newtonian image source can be

John N. Bahcall

There are four important facts about solar neutrinos. They are listed in order of importance in this abstract and discussed more in the text of the talk. First, solar neutrinos have been detected in four experiments with approximately the energies and fluxes predicted by the standard solar model, confirming the hypothesis that the energy source for the solar

R. Delbourgo, A. B. Waites

One of the interesting features about field theories in odd dimensions is the induction of parity violating terms and well-defined {\em finite} topological actions via quantum loops if a fermion mass term is originally present and conversely. Aspects of this issue are illustrated for electrodynamics in 2+1 and 4+1 dimensions. (3 uuencoded Postscript Files ar

Xiaochun Luo

Non-Gaussian distributions of cosmic microwave background (CMB) anisotropies have been proposed to reconcile the discrepancies between different experiments at half-degree scales (Coulson et al. 1994). Each experiment probes a different part of the sky, furthermore, sky coverage is very small, hence the sample variance of each experiment can be large, especi

Rodanthy Tzani

The stochastic quantization of dissipative systems is discussed. It is shown that in order to stochastically quantize a system with dissipation, one has to restrict the Fourier transform of the space-time variable to the positive half domain in the complex plane. This breaks the time-reversal invariance, which manifests in the formulation through the resulti

G. J. Chaitin

This is a shortened version of "The Limits of Mathematics--Course Outline & Software" (IBM Research Report RC 19324, December 1993) in which all Mathematica code has either been deleted or, if absolutely necessary, replaced by C code. The intention is to make this material available to a wider audience.

Francesco Mauri, Giulia Galli

We present a method for total energy minimizations and molecular dynamics simulations based either on tight-binding or on Kohn-Sham hamiltonians. The method leads to an algorithm whose computational cost scales linearly with the system size. The key features of our approach are (i) an orbital formulation with single particle wavefunctions constrained to be l

Mary Dalrymple, John Lamping, Fernando Pereira, Vijay Saraswat

The relationship between Lexical-Functional Grammar (LFG) functional structures (f-structures) for sentences and their semantic interpretations can be expressed directly in a fragment of linear logic in a way that explains correctly the constrained interactions between quantifier scope ambiguity and bound anaphora. The use of a deductive framework to account

Michael B. Green

Auxiliary string fields are introduced in light-cone gauge string field theory in order to express contact interactions as contractions of cubic vertices. The auxiliary field in the purely closed-string bosonic theory may be given a non-zero expectation value, leading to a phase in which world-sheets have boundaries.

Jonathan Beck

We lift the lattice of translations in the extended affine Weyl group to a braid group action on the quantum affine algebra. This action fixes the Heisenberg subalgebra pointwise. Loop like generators are found for the algebra which satisfy the relations of Drinfel$'$d's new realization. Coproduct formulas are given and a PBW type basis is constructed.

Marc Sher

This is an addendum to the paper of the above title published in Physics Letters B317, 159 (1993). In that paper, I found the lower bound to the Higgs mass as a function of the top quark mass one obtains by requiring that the standard model vacuum be stable. It included all higher order corrections to two-loops, precise definitions of the Higgs and top masse

E. Norvaišas, D. O. Riska

We construct the representations of general dimension for the soliton solution to the $SU(2)$ Skyrme model, and show that at the classical level the dependence on the dimension of the representation ($2j+1$) appears only as an overall factor $j(j+1)(2j+1)$ in the Lagrangian density, which may be absorbed by a rescaling of the parameters. Alternate stabilizin

Bruce Allen, Scott Koranda

We examine stochastic temperature fluctuations of the cosmic background radiation (CBR) arising via the Sachs-Wolfe effect from gravitational wave perturbations produced in the early universe. These temperature fluctuations are described by an angular correlation function $C(\gamma)$. A new (more concise and general) derivation of $C(\gamma)$ is given, and e

T. Swahn, E. N. Bogachek, Yu. M. Galperin, M. Jonson

We show that Aharonov-Bohm (AB) oscillations in the magnetic moment of an integrable ballistic quantum dot can be destroyed by a time dependent magnetic flux. The effect is due to a nonequilibrium population of perfectly coherent electronic states. For real ballistic systems the equilibrization process, which involves a special type of inelastic electron bac

Eduardo Cattani, Alicia Dickenstein, Bernd Sturmfels

Given n polynomials in n variables with a finite number of complex roots, for any of their roots there is a local residue operator assigning a complex number to any polynomial. This is an algebraic, but generally not rational, function of the coefficients. On the other hand, the global residue, which is the sum of the local residues over all roots, depends r

G. J. Gounaris, J. Layssac, F. M. Renard

We study the sensitivity of Higgs production and decay processes to the $SU(2)_c$ symmetric couplings $O_W$ and $O_{UW}$. Remarkable results are obtained in the case of $\gamma \gamma \to H$ and for certain ratios of Higgs decay widths. We also discuss and complete previous results on unitarity constraints for such couplings.

A. P. Gottlob, M. Hasenbusch

We present the results of a Monte Carlo study of the three-dimensional anti-ferromagnetic 3-state Potts model. We compute various cumulants in the neighbourhood of the critical coupling. The comparison of the results with a recent high statistics study of the 3D XY model strongly supports the hypothesis that both models belong to the same universality class.

J. F. Gunion, J. G. Kelly

We determine the optimal laser and $\ep/\em$ energies and polarizations for {\it directly} determining the CP eigenvalue of each of the neutral Higgs bosons of the Minimal Supersymmetric Model via measurement of transverse polarization cross section asymmetry in back-scattered laser photon collisions. Approximate statistical significances are computed for th