December 1996 arXiv papers — page 8

James Schombert, Rachel Pildis, Jo Ann Eder

This project is a visual search for field dwarf galaxies using Second Palomar Sky Survey photographic plates. A morphologically selected sample of 310 objects yielded 145 detections of true dwarfs within a redshift search window of 0 to 10,000 km sec^-1. We confirm the low mass, dwarf nature of the same by comparison of luminosity, isophotal size, HI mass an

I. -A. Yadigaroglu

Previous studies have shown that the largest gamma-ray detector to date, EGRET, does not have useful polarization sensitivity. We have explored here some improved approaches to analyzing gamma-ray pair production events, leading to important gains in sensitivity to polarization. The performance of the next generation gamma-ray instrument GLAST is investigate

Xingming Chen, Jean H. Swank, Ronald E. Taam

From data obtained from the PCA in the 2-11 keV and 11-30.5 keV energy range, GRS 1915+105 is seen during RXTE observations between 1996 May and October on two separate branches in a hardness intensity diagram. On the hard branch, GRS 1915+105 exhibits narrow quasi-periodic oscillations ranging from 0.5 to 6 Hz with ${Δν\over ν} \sim 0.2$. The QPOs are obser

Xingming Chen, Ronald E. Taam, Marek A. Abramowicz, Igor V. Igumenshchev

The morphology of adiabatic accretion flows with small non-zero specific angular momentum has been investigated in the axisymmetric and nonviscous limit. For an initial state characterized by a Bondi flow with the specific angular momentum distributed with respect to polar angle, a travelling shock wave forms which propagates more rapidly in the equatorial p

Nickolay Y. Gnedin, Jeremiah P. Ostriker

We simulate a plausible cosmological model in considerable physical and numerical detail through the successive phases of reheating (at 10<z<20), formation of Pop III stars at z=15 (due to molecular hydrogen cooling), with subsequent reionization at z=7. We assume an efficiency of high mass star formation appropriate to leave the universe, after it becomes t

J. Socorro, H. C. Rosu

We briefly present the supersymmetric double Darboux method and next apply it to the continuum of the quantum Taub cosmological model as a toy model in order to generate a one-parameter family of bosonic Taub potentials and the corresponding wavefunctions

Miao Li

We discuss how to construct open membranes in the recently proposed matrix model of M theory. In order to sustain an open membrane, two boundary terms are needed in the construction. These boundary terms are available in the system of the longitudinal five-branes and D0-branes.

David P. DiVincenzo

I provide an introduction to quantum computers, describing how they might be realized using language accessible to a solid state physicist. A listing of the minimal requirements for creating a quantum computer is given. I also discuss several recent developments in the area of quantum error correction, a subject of importance not only to quantum computation,

Bruce A. Schumm

Based on the PYTHIA physics simulation package, and a fast simulation of the proposed detector for the Next Linear Collider, a set of cuts is identified which leads to a sample of e+e- -> qq events appropriate for the precise measurement of alpha_s in e+e- annihilation at sqrt(s) = 500 GeV/c^2. Using these cuts, the systematic uncertainty on alpha_s associat

H. J. Bussemaker, R. Brito

A kinetic description of lattice-gas automaton models for reaction-diffusion systems is presented. It provides corrections to the mean-field rate equations in the diffusion-limited regime. When applied to the two-species Maginu model, the theory gives an excellent quantitative prediction of the effect of slow diffusion on the periodic oscillations of the ave

P. N. Burrows, L. Dixon, A. X. El-Khadra, J. W. Gary

The prospects for the measurement of the strong coupling constant alpha_msbar(M_Z) to a relative uncertainty of 1% are discussed. Particular emphasis is placed on the implications relating to future High Energy Physics facilities.

Tomas Ortin

We study general black-hole solutions of the low-energy string effective action in arbitrary dimensions using a general metric that can describe them all in a unified way both in the extreme and non-extreme cases. We calculate the mass, temperature and entropy and study which relations amongst the charges and the mass lead to extremality. We find that the te

Rolf Schimmrigk

Recent work is reviewed which suggests that certain universal quantities, defined for all Calabi-Yau manifolds, exhibit a specific behavior which is not present for general Kähler manifolds. The variables in question, natural from a mathematical perspective, are of physical importance because they determine aspects of the low-energy string physics in four di

Cosmin Popovici, Paolo Baggia

This paper analyses language modeling in spoken dialogue systems for accessing a database. The use of several language models obtained by exploiting dialogue predictions gives better results than the use of a single model for the whole dialogue interaction. For this reason several models have been created, each one for a specific system question, such as the

Stephane Cueille, Clement Sire

We consider the scaling solutions of Smoluchowski&#39;s equation of irreversible aggregation, for a non gelling collision kernel. The scaling mass distribution f(s) diverges as s^{-tau} when s->0. tau is non trivial and could, until now, only be computed by numerical simulations. We develop here new general methods to obtain exact bounds and good approximati

Atsushi Moriwaki

Let f : X --> Y be a projective morphism of smooth algebraic varieties over an algebraically closed field of characteristic zero with dim f = 1. Let E be a vector bundle of rank r on X. In this paper, we would like to show that if X_y is smooth and E_y is semistable for some point y of Y, then f_* (2r c_2(E) - (r-1) c_1(E)^2) is weakly positive at y. We appl

G. Korniss, B. Schmittmann, R. K. P. Zia

We investigate the dynamics of a three-state stochastic lattice gas, consisting of holes and two oppositely &#34;charged&#34; species of particles, under the influence of an &#34;electric&#34; field, at zero total charge. Interacting only through an excluded volume constraint, particles can hop to nearest neighbour empty sites. Using a combination of Langevi

Wolfgang Ebeling

We give a survey on old and new results concerning Arnold&#39;s strange duality. We show that most of the features of this duality continue to hold for the extension of it discovered by C. T. C. Wall and the author. The results include relations to mirror symmetry and the Leech lattice.

A. N. Sissakian, O. Yu. Shevchenko, S. B. Solganik

The Chern-Simons topological term coefficient is derived at arbitrary finite density. As it occures that $μ^2 = m^2$ is the crucial point for Chern-Simons. So when $μ^2 < m^2 μ$--influence disappears and we get the usual Chern-Simons term. On the other hand when $μ^2 > m^2$ the Chern-Simons term vanishes because of non-zero density of background fermions. In

E. Marco, E. Oset

We have made a thorough investigation of the nuclear structure function W_2A in the region of 0.8 < x < 1.5 and Q^2 < 20 GeV^2, separating the quasielastic and inelastic plus deep inelastic contributions. The agreement with present experimental data is good giving support to the results for both channels. Predictions are made in yet unexplored regions of x a

Holger F. Hofmann

A new approach to chemical bonding is introduced in order to provide an improved understanding of the connection between basic quantum mechanics and the covalent pair bond. It&#39;s focus is on the fact that the energy of the bond is largely given by the kinetic energy of the electrons, while the Coulomb forces are only comparable to the kinetic energy terms

Mathias Pillin

We derive closed recursion equations for the symmetric polynomials occuring in the form factors of $D_n^{(1)}$ affine Toda field theories. These equations follow from kinematical- and bound state residue equations for the full form factor. We also discuss the equations arising from second and third order forward channel poles of the S-matrix. The highly symm

M. Carena, G. F. Giudice, S. Lola, C. E. M. Wagner

ALEPH has reported a significant excess of four-jet events in the LEP runs above the Z^0 resonance, which however has not been confirmed by the other LEP collaborations. We assume here that this excess corresponds to a physics signal and try to interpret it in the context of supersymmetric models with R-parity violation. Associated production of a left and r

Ali Mostafazadeh

Quantum canonical transformations corresponding to the action of the unitary operator $e^{iε(t)\sqrt{f(x)}p\sqrt{f(x)}}$ is studied. It is shown that for $f(x)=x$, the effect of this transformation is to rescale the position and momentum operators by $e^{ε(t)}$ and $e^{-ε(t)}$, respectively. This transformation is shown to lead to the identification of a pre

Wojciech Hubert Zurek, Juan Pablo Paz

Violation of correspondence principle may occur for very macroscopic byt isolated quantum systems on rather short timescales as illustrated by the case of Hyperion, the chaotically tumbling moon of Saturn, for which quantum and classical predictions are expected to diverge on a timescale of approximately 20 years. Motivated by Hyperion, we review salient fea

Luciana Dávila Romero, Juan Pablo Paz

We analyze the evolution of a quantum Brownian particle starting from an initial state that contains correlations between this system and its environment. Using a path integral approach, we obtain a master equation for the reduced density matrix of the system finding relatively simple expressions for its time dependent coefficients. We examine the evolution

C. J. Isham, N. Linden

In standard quantum theory, the ideas of information-entropy and of pure states are closely linked. States are represented by density matrices $ρ$ on a Hilbert space and the information-entropy $-tr(ρ\logρ)$ is minimised on pure states (pure states are the vertices of the boundary of the convex set of states). The space of decoherence functions in the consis

Seth Lloyd

A Maxwell&#39;s demon is a device that gets information and trades it in for thermodynamic advantage, in apparent (but not actual) contradiction to the second law of thermodynamics. Quantum-mechanical versions of Maxwell&#39;s demon exhibit features that classical versions do not: in particular, a device that gets information about a quantum system disturbs

Yves Brihaye

We analyse the Witten-Woronowicz&#39;s type deformations of the Lie superalgebra osp(2,2) and obtain a deformation parametrized by three independent parameters. For some of these algebras, finite dimensional representations are formulated in terms of a finite difference operator, providing operators that are relevant for the classification of quasi exactly s

R. B. Zhang

The finite dimensional irreducible representations of the quantum supergroup $U_q(gl(m|n))$ are constructed geometrically using techniques from the Bott - Borel - Weil theory and vector coherent states.

M. D. Gould, N. I. Stoilova

A full set of (higher order) Casimir invariants for the Lie algebra $gl(\infty )$ is constructed and shown to be well defined in the category $O_{FS}$ generated by the highest weight (unitarizable) irreducible representations with only a finite number of non-zero weight components. Moreover the eigenvalues of these Casimir invariants are determined explicitl

A. Leviatan, R. Bijker

We present an algebraic approach to the internal structure of baryons in terms of three constituents. We investigate a collective model in which the nucleon is regarded as a rotating and vibrating oblate top with a prescribed distribution of charges and magnetization. We contrast the collective and single-particle descriptions of baryons and compare the pred

P. Fernández de Córdoba, E. Marco, H. Müther, E. Oset

We analyze the processes of deep inelastic and quasielastic scattering in the region of x > 1. These processes are found to be very sensitive to the information contained in the nucleon spectral function in nuclei, particularly to the correlations between energy and momentum. Calculations are done using two spectral functions for nuclear matter and one for f

E. Marco, E. Oset, P. Fernández de Córdoba

Starting from a covariant relativistic formalism which uses nucleon and pion propagators in a nuclear medium, we revise the traditional effects of Fermi motion, binding and mesonic corrections to the EMC effect. The calculations are done in a very accurate way, using precise nucleon spectral functions and meson self-energies and a good reproduction of the EM

L. P. Kaptari, B. Kaempfer, S. M. Dorkin, S. S. Semikh

The exclusive deuteron break-up reaction is analyzed within a covariant approach based on the Bethe-Salpeter equation with realistic meson-exchange interaction. Relativistic effects in the cross section, tensor analyzing power and polarization transfer are investigated in explicit form. Results of numerical calculations are presented for kinematical conditio

L. G. Moretto, K. Tso, G. J. Wozniak

Coulomb bubbles, though stable against monopole displacement, are unstable at least with respect to quadrupole and octupole distortions. We show that there exists a temperature at which the pressure of the vapor filling the bubble stabilizes all the radial modes. In extremely thin bubbles, the crispation modes become unstable due to the surface-surface inter

A. Stern, P. Vitale

We apply the SL(2,C) lattice Kac-Moody algebra of Alekseev, Faddeev and Semenov-Tian-Shansky to obtain a new lattice description of the SU(2) chiral model in two dimensions. The system has a global quantum group symmetry and it can be regarded as a deformation of two different theories. One is the nonabelian Toda lattice which is obtained in the limit of inf

Matthias Blau, George Thompson

We comment on various aspects of topological gauge theories possessing N_{T}\geq 2 topological symmetry: (1) We show that the construction of Vafa-Witten and Dijkgraaf-Moore of `balanced&#39; topological field theories is equivalent to an earlier construction in terms of N_{T}=2 superfields inspired by Susy QM. (2) We explain the relation between topological

Shibaji Roy

We consider several orbifold compactifications of M-theory and their corresponding type II duals in two space-time dimensions. In particular, we show that while the orbifold compactification of M-theory on $T^9/J_9$ is dual to the orbifold compactification of type IIB string theory on $T^8/I_8$, the same orbifold $T^8/I_8$ of type IIA string theory is dual t

A. Herrera, O. Kechkin

The Ernst-like matrix representation of the multidimensional Einstein-Kalb-Ramond theory is developed and the O(d,d)-symmetry is presented in the matrix-valued SL(2,R)-form. The analogy with the Einstein and Einstein-Maxwell-Dilaton-Axion theories is discussed.

E. Corrigan

Talks given at the workshop ``Frontiers in Quantum Field Theory&#39;&#39;, held in Urumqi, Xinjiang Uygur Autonomous Region, People&#39;s Republic of China, 11-19 August 1996.

T. Kopf, A. E. Santana, F. C. Khanna

In Thermal Field Dynamics, thermal states are obtained from restrictions of vacuum states on a doubled field algebra. It is shown that the suitably doubled Fock representations of the Heisenberg algebra do not need to be introduced by hand but can be canonically handed down from deformations of the extended Heisenberg bialgebra. No artificial redefinitions o

Pawel O. Mazur

Topology change in quantum gravity is considered. An exact wave function of the Universe is calculated for topological Chern-Simons 2+1 dimensional gravity. This wave function occurs as the effect of a quantum anomaly which leads to the induced gravity. We find that the wave function depends universally on the topology of the two-dimensional space. Indeed, t

Pawel O. Mazur, V. P. Nair

We propose the theory of quantum gravity with interactions introduced by topological principle. The fundamental property of such a theory is that its energy-momentum tensor is an BRST anticommutator. Physical states are elements of BRST cohomology group. The model with only topological excitations, introduced recently by Witten is discussed from the point of

Soonkeon Nam

We consider the close relation between duality in N=2 SUSY gauge theories and integrable models. Various integrable models ranging from Toda lattices, Calogero models, spinning tops, and spin chains are related to the quantum moduli space of vacua of N=2 SUSY gauge theories. In particular, SU(3) gauge theories with two flavors of massless quarks in the funda

Jan de Boer, Kentaro Hori, Hirosi Ooguri, Yaron Oz

We construct intersecting D-brane configurations that encode the gauge groups and field content of dual N=4 supersymmetric gauge theories in three dimensions. The duality which exchanges the Coulomb and Higgs branches and the Fayet-Iliopoulos and mass parameters is derived from the SL(2,Z) symmetry of the type IIB string. Using the D-brane configurations we

Glennys R. Farrar, Marta Losada

We analyze the effective 3 dimensional theory previously constructed for the MSSM and multi-Higgs models to determine the regions of parameter space in which the electroweak phase transition is sufficiently strong for a $B+L$ asymmetry to survive in the low temperature phase. We find that the inclusion of all supersymmetric scalars and all 1-loop corrections

P. A. Raczka

The next-to-next-to-leading order perturbative QCD corrections to R_tau and the higher moments of the invariant mass distribution in the hadronic tau decays are considered. The renormalization scheme dependence of these corrections is discussed. The optimized predictions are obtained, using the principle of minimal sensitivity as a guide to select the prefer

F. W. Bopp, R. Engel, A. Rostovtsev

A simple phenomenological introduction to the physics of multi-pomeron exchange amplitudes in connection with the Abramovski-Gribov-Kancheli (AGK) cutting rules is given. The AGK cutting rules are applied to obtain qualitative and quantitative predictions on multiparticle production at high energies. On this basis, particle production in hadron-hadron scatte

Alex Kovner

It is pointed out that the low energy effective theory that describes the low lying glueballs of the pure Yang Mills theory sustains static classical stringlike solutions. We suggest that these objects can be identified with the QCD flux tubes and their energy per unit length with the string tension.

Mikulas Gintner, Stephen Godfrey

We examine t tbar production via vector boson fusion at high energy e^+ e^- colliders using the effective vector-boson approximation. We show cross sections as functions of CM energy for various Higgs masses ranging from 100 GeV up to 1 TeV, and also for M_H = infinity which corresponds to the LET. We give expressions for sigma(V_i V_j -> t tbar) in the 2M_(

T. N. Tomaras

The main features of the recently found classically stable quasi-topological membranes and strings in generic, topologically trivial and weakly coupled two-Higgs extensions of the standard model are briefly reviewed. A variety of localized solutions in the same model are also presented.

C. Greub, P. Minkowski

We discuss the process $e^-e^- \to W^- W^-$ mediated by heavy Majorana neutrino exchange in the t- and u channel. In our model the cross section for this reaction is a function of the masses (m_N) of the heavy Majorana neutrinos and mixing parameters (U_{eN}) originating from mixing between the ordinary left-handed standard model neutrinos and additional sin

Christopher Balzereit, Thorsten Ohl

We present a calculation of the renormalized heavy-light and heavy-heavy currents in HQET at order O(1/m_Q^2).

Michael Rueter

We calculate the C=P=-1 contribution to high-energy scattering of hadrons in the framework of the model of the stochastic vacuum. In models, where the pomeron is generated by a two gluon exchange, this odderon contribution comes from a three gluon exchange and is much too large as compared to experimental data for pp- and $p\bar{p}$-scattering. In our model,

Marta Losada

Using dimensional reduction we construct an effective 3D theory of the Minimal Supersymmetric Standard Model at finite temperature. The final effective theory is obtained after three successive stages of integration out of massive particles. We obtain the full 1-loop relation between the couplings of the reduced theory and the underlying 4D couplings and mas

B. Kaempfer

Utilizing a hydrodynamical model for the freeze-out stage in heavy-ion reactions, we extract from resolved transverse hadron spectra at midrapidity an inverse slope parameter (temperature) $T_{Pb} =$ 120 MeV and an averaged transverse flow velocity $v_{\perp Pb}^{aver} =$ 0.43 c in central collisions of Pb + Pb at 158 AGeV.

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

We study the potential of a future $e^+e^-$ collider for the search of anomalous gamma t t bar and Z t t bar couplings, assuming that CP-invariance holds. This is done in a model-independent way, considering that all six possible couplings do appear. Two experimental situations are envisaged, with and without electron beam polarization. Observability limits

S. Abachi

A search for signals of new physics has been carried out in the channel p pbar -> gamma gamma + ETmiss. This signature is expected in various recently proposed supersymmetric (SUSY) models. We observe 842 events with two photons having transverse momentum ET(g) > 12 GeV and pseudorapidity |eta(g)| < 1.1. Of these, none have missing transverse energy (ETmiss)

Fritz DeJongh, George Michail

We describe two measurements of Delta m_d. The first uses B -> nu l D(*) events and a same-side flavor tagging algorithm. The second uses dilepton events. From the average of these two measurements we find Delta m_d = 0.466 +- 0.037 +- 0.031 ps^{-1}.

D0 Collaboration, S. Abachi

This report describes the first search for top squark pair production in the channel stop_1 stopbar_1 -> b bbar chargino_1 chargino_1 -> ee+jets+MEt using 74.9 +- 8.9 pb^-1 of data collected using the D0 detector. A 95% confidence level upper limit on sigma*B is presented. The limit is above the theoretical expectation for sigma*B for this process, but does

J. Gegenberg, G. Kunstatter, T. Strobl

In several recent publications Carlip, as well as Balachandran, Chandar and Momen, have proposed a statistical mechanical interpretation for black hole entropy in terms of ``would be gauge&#39;&#39; degrees of freedom that become dynamical on the boundary to spacetime. After critically discussing several routes for deriving a boundary action, we examine thei

C. Alvarez, R. B. Mann

We consider possible tests of the Einstein Equivalence Principle for quantum-mechanical vacuum energies by evaluating the Lamb shift transition in a class of non-metric theories of gravity described by the \tmu formalism. We compute to lowest order the associated red shift and time dilation parameters, and discuss how (high-precision) measurements of these q

Giorgio Immirzi

Both real and complex connections have been used for canonical gravity: the complex connection has SL(2,C) as gauge group, while the real connection has SU(2) as gauge group. We show that there is an arbitrary parameter $β$ which enters in the definition of the real connection, in the Poisson brackets, and therefore in the scale of the discrete spectra one f

Adam D. Helfer

Building on the &#34;quantum inequalities&#34; introduced by Ford, I argue that the negative local energies encountered in quantum field theory can only be observed by detectors with positive energies at least as great in magnitude. This means that operationally the total energy density must be non-negative. Like reasoning shows that, in a similar operationa

David P. DiVincenzo

A brief review is given of the physical implementation of quantum computation within spin systems or other two-state quantum systems. The importance of the controlled-NOT or quantum XOR gate as the fundamental primitive operation of quantum logic is emphasized. Recent developments in the use of quantum entanglement to built error-robust quantum states, and t

B. Schmittmann, C. A. Laberge

We investigate the effects of quenched randomness on the universal properties of a two-temperature lattice gas. The disorder modifies the dynamical transition rates of the system in an anisotropic fashion, giving rise to a new fixed point. We determine the associated scaling form of the structure factor, quoting critical exponents to two-loop order in an exp

N. M. R. Peres, J. M. P. Carmelo, D. K. Campbell, A. W. Sandvik

We extend the pseudoparticle transport description of the Hubbard chain to all energy scales. In particular we compute the mean value of the electric current transported by any Bethe-ansatz state and the transport masses of the charge carriers. We present numerical results for the optical conductivity of the model at half-filling for values of U/t=3 and 4. W

M. B. Hastings

The circular orthogonal and circular symplectic ensembles are mapped onto free, non-hermitian fermion systems. As an illustration, the two-level form factors are calculated.

Z. Toroczkai, R. K. P. Zia

Analytic solution is given in the steady state limit for the system of Master equations describing a random walk on one-dimensional periodic lattices with arbitrary hopping rates containing one mobile, directional impurity (defect bond). Due to the defect, translational invariance is broken, even if all other rates are identical. The structure of Master equa

Klaus M. Frahm, Dima L. Shepelyansky

We study the level spacing statistics p(s) and eigenfunction properties in a billiard with a rough boundary. Quantum effects lead to localization of classical diffusion in the angular momentum space and the Shnirelman peak in p(s) at small s. The ergodic regime with Wigner-Dyson statistics is identified as a function of roughness. Applications for the Q-spoi

K. N. Ilinski, A. S. Stepanenko

Self-consistent hydrodynamic one-loop quantum corrections to the Gross-Pitaevskii equation due to the interaction of the condensate with collective excitations are calculated. It is done by making use a formalism of effective action and $ζ$-function regularization for a contribution from Bogoliubov particles in hydrodynamic approximation. It turns out to be

N. Kawashima, H. Rieger

With the help of EXACT ground states obtained by a polynomial algorithm we compute the domain wall energy at zero-temperature for the bond-random and the site-random Ising spin glass model in two dimensions. We find that in both models the stability of the ferromagnetic AND the spin glass order ceases to exist at a UNIQUE concentration p_c for the ferromagne

Axel Voelker, Peter Kopietz

The effect of the Coulomb-interaction on persistent currents in disordered mesoscopic metal rings threaded by a magnetic flux $ϕ$ is studied numerically. We use the simplest form of ``self-consistent&#39;&#39; Hartree theory, where the spatial variations of the self-consistent Hartree potential are ignored. In this approximation the self-consistent Hartree e

Jacek Dziarmaga, Meik Hellmund

Skyrmions in the FQHE at filling fractions above ν=1/3 are studied within the anyon model and by exact diagonalization. Relations to the composite fermion theory are pointed out. We find that unpolarized quasiparticles above ν=1/3 are stable below B\approx 0.02T. At low Zeeman energy the polarization in the range ν=8/5 ... 5/3 is found to be a linear functio

Andreas Schadschneider, Michael Schreckenberg

We present a new analytical description of the cellular automaton model for single-lane traffic. In contrast to previous approaches we do not use the occupation number of sites as dynamical variable but rather the distance between consecutive cars. Therefore certain longer-ranged correlations are taken into account and even a mean-field approach yields non-t

Alon Drory, Brian Berkowitz, Giorgio Parisi, I. Balberg

We use a previously introduced mapping between the continuum percolation model and the Potts fluid (a system of interacting s-states spins which are free to move in the continuum) to derive the low density expansion of the pair connectedness and the mean cluster size. We prove that given an adequate identification of functions, the result is equivalent to th

H. Waalkens, J. Wiersig, H. R. Dullin

The exact and semiclassical quantum mechanics of the elliptic billiard is investigated. The classical system is integrable and exhibits a separatrix, dividing the phasespace into regions of oscillatory and rotational motion. The classical separability carries over to quantum mechanics, and the Schrödinger equation is shown to be equivalent to the spheroidal

Per Dahlqvist

We review the status of the semiclassical trace formula with emphasis on the particular types of singularities that occur in the Gutzwiller-Voros zeta function for bound chaotic systems. To understand the problem better we extend the discussion to include various classical zeta functions and we contrast properties of axiom-A scattering systems with those of

J. Greiner, M. L. Hazen

We have re-identified HV 2554 on plates of the Harvard College Observatory. Using photographic plates with higher sensitivity and spatial resolution taken within the EROS programme we do not find any variability. This suggests that a combination of variable seeing and different limiting magnitudes of the Harvard plates result in a different size of the image

R. P. Fender, S. J. Bell Burnell, E. B. Waltman, G. G. Pooley

We present multiwavelength observations of Cygnus X-3 during an extended outburst in 1994 February - March. Intensive radio monitoring at 13.3, 3.6 & 2.0 cm is complemented by observations at (sub)millimetre and infrared wavelengths, which find Cyg X-3 to be unusually bright and variable, and include the first reported detection of the source at 0.45 mm. We

R. Capuzzo-Dolcetta, R. Di Lisio, P. Miocchi

A modern approach to the evolution of a mixed (stars and gas) self-gravitating system is the fully Lagrangian particle approach. The gaseous (particle) phase differs from the compact because the mutual force is given by the sum of gravity and pressure gradient. In this note we report of some characteristics, advantages and limitations of this approach for wh

L. Bergstrom

At the AMANDA South Pole site, four new holes were drilled to depths 2050 m to 2180 m and instrumented with 86 photomultipliers (PMTs) at depths 1520-2000 m. Of these PMTs 79 are working, with 4-ns timing resolution and noise rates 300 to 600 Hz. Various diagnostic devices were deployed and are working. An observed factor 60 increase in scattering length and

David Tytler, Scott Burles, David Kirkman

The spectrum of quasar 0014+813 was the first in which deuterium was claimed to be observed, at first as a probable detection, and later ``confirmed&#39;&#39;. It is important because it is the only case in which there is a serious likelihood of a high D/H ratio, since the others are more ambiguous and admit a wide range of D/H including zero. We present new

Gavin Polhemus

The D-brane counting of black hole entropy is commonly understood in terms of excitations carrying fractional charges living on long, multiply-wound branes (e.g. open strings with fractional Kaluza-Klein momentum). This paper addresses why the branes become multiply wound. Since multiply wound branes are T-dual to branes evenly spaced around the compact dime

Jonathan L. Feng, Takeo Moroi

We examine the prospects for determining $tan β$ from heavy Higgs scalar production in the minimal supersymmetric standard model at a future $e^+ e^-$ collider. Our analysis is independent of assumptions of parameter unification, and we consider general radiative corrections in the Higgs sector. Bounds are presented for $\sqrt{s} = 500$ GeV and 1 TeV, severa

John T. Whelan

The question of whether unobserved short-wavelength modes of the gravitational field can induce decoherence in the long-wavelength modes (``the decoherence of spacetime&#39;&#39;) is addressed using a simplified model of perturbative general relativity, related to the Nordstrom-Einstein-Fokker theory, where the metric is assumed to be conformally flat. For s

G. Dvali, M. Shifman

Domain walls in strongly coupled gauge theories are discussed. A general mechanism is suggested automatically leading to massless gauge bosons localized on the wall. In one of the models considered, outside the wall the theory is in the non-Abelian confining phase, while inside the wall it is in the Abelian Coulomb phase. Confining property of the non-Abelia

C. Wexler

The total transverse force acting on a quantized vortex in a superfluid is a problem that has eluded a complete understanding for more than three decades. In this letter I propose a remarkably simple argument, somewhat reminiscent of Laughlin&#39;s beautiful argument for the quantization of conductance in the quantum Hall effect, to define the superfluid vel

T. Csorgo, B. Lorstad

An analytically calculable model has been proposed recently for the simultaneous description of particle spectra and correlations, which is able to explain in a natural manner the $m_t$ scaling of the radius parameters of the Bose--Einstein correlation functions. We present here preliminary results on fitting this model to data sampled by NA44 collaboration

M. Asakawa, T. Csorgo

We discuss the possibility to observe hadron modification in hot matter via the correlation of identical particles. We find that the hadron modification causes a new type of correlation, back-to-back correlation.

G. Korniss, B. Schmittmann, R. K. P. Zia

We investigate the dynamics of a three-state stochastic lattice gas, consisting of holes and two oppositely &#34;charged&#34; species of particles, under the influence of an &#34;electric&#34; field, at zero total charge. Interacting only through an excluded volume constraint, particles can hop to nearest neighbour empty sites. With increasing density and dr

Tim R. Morris

We show that non-perturbative fixed points of the exact renormalization group, their perturbations and corresponding massive field theories can all be determined directly in the continuum -- without using bare actions or any tuning procedure. As an example, we estimate the universal couplings of the non-perturbative three-dimensional one-component massive sc

Joseph Silk

Self-regulation of star formation in disks is controlled by two dimensionless parameters: the Toomre parameter for gravitational instability and the porosity of the interstellar medium to supernova remnant-heated gas. An interplay between these leads to expressions for the gas fraction and star formation efficiency in disks, and to a possible explanation of

Gabriel Tellez

In this paper we study a model for the sedimentation equilibrium of a charged colloidal suspension: the two-dimensional two-component plasma in a gravitational field which is exactly solvable at a special value of the reduced inverse temperature Gamma=2. The density profiles are computed. The heavy particles accumulate at the bottom of the cointainer. If the

P. K. Townsend

Synopsis: (i) how superstring theories are unified by M-theory; (ii) how superstring and supermembrane properties follow from the D=10 and D=11 supersymmetry algebras; (iii) how D=10 and D=11 supergravity theories determine the strong coupling limit of superstring theories; (iv) how properties of Type II p-branes follow from those of M-branes.

Mario Atance, Jose Luis Cortes

A general discussion of the renormalization of the quantum theory of a scalar field as an effective field theory is presented. The renormalization group equations in a mass-independent renormalization scheme allow us to identify the possibility to go beyond the renormalizable $ϕ^{4}$ theory without losing its predictive power. It is shown that there is a min

H. Dorn

We construct a calculational scheme for handling the matrix ordering problems connected with the appearance of D-brane positions taking values in the same Lie algebra as the nonabelian gauge field living on the D-brane. The formalism is based on the use of an one-dimensional auxiliary field living on the boundary of the string world sheet and taking care of

Ricardo Amorim, Nelson R. F. Braga

The Batalin Vilkovisky (BV) quantization provides a general procedure for calculating anomalies associated to gauge symmetries. Recent results show that even higher loop order contributions can be calculated by introducing an appropriate regularization-renormalization scheme. However, in its standard form, the BV quantization is not sensible to quantum viola

Markus J. Pflaum

For an arbitrary Riemannian manifold $X$ and Hermitian vector bundles $E$ and $F$ over $X$ we define the notion of the normal symbol of a pseudodifferential operator $P$ from $E$ to $F$. The normal symbol of $P$ is a certain smooth function from the cotangent bundle $T^*X$ to the homomorphism bundle $Hom (E,F)$ and depends on the metric structures resp. the