January 1996 arXiv papers — page 8

Alejandro Gangui, Silvia Mollerach

Using an analytical model for the Cosmic Microwave Background anisotropies produced by textures, we compute the resulting collapsed three--point correlation function and the {\it rms} expected value due to the cosmic variance. We apply our calculations to the {\sl COBE}--DMR experiment and test the consistency of the model with the observational results. We

Jerzy Kowalski-Glikman, Krzysztof A. Meissner

After carefully regularizing the Wheeler -- De Witt operator, which is the Hamiltonian operator of canonical quantum gravity, we find a class of exact solutions of the Wheeler -- De Witt equation.

Anders Irbäck, Frank Potthast

We develop a simple optimization procedure for assigning binary values to the amino acids. The binary values are determined by a maximization of the degree of pattern conservation in groups of closely related protein sequences. The maximization is carried out at fixed composition. For compositions approximately corresponding to an equipartition of the residu

Nobuaki Nagao, Hiroshi Suzuki

Using a simple solvable model, i.e., Higgs--Yukawa system with an infinite number of flavors, we explicitly demonstrate how a dimensional continuation of the $β$ function in two dimensional MS scheme {\it fails\/} to reproduce the correct behavior of the $β$ function in four dimensions. The mapping between coupling constants in two dimensional MS scheme and

Phung Ho Hai

Central bialgebras in a braided category $\C$ are algebras in the center of the category of coalgebras in $\C$. On these bialgebras another product can be defined, which plays the role of the opposite product. Hence, coquasitriangular structures on central bialgebras can be defined. We prove some properties of the antipode on coquasitriangular central Hopf a

Joseph A. Minahan, Dennis Nemeschansky

We discuss $SL(2,Z)$ subgroups appropriate for the study of $N=2$ Super Yang-Mills with $N_f=2n$ flavors. Hyperelliptic curves describing such theories should have coefficients that are modular forms of these subgroups. In particular, uniqueness arguments are sufficient to construct the $SU(3)$ curve, up to two numerical constants, which can be fixed by maki

Z. Haba

We consider a class of models describing a quantum oscillator in interaction with an environment. We show that models of continuous spontaneous localization based on a stochastic Schrödinger equation can be derived as an approximation to purely deterministic Hamiltonian systems. We show an exponential decay of off-diagonal matrix elements in the energy repre

S. Dasmahapatra, O. Foda

For the vacuum sectors of regime-III ABF models, we observe that two sets of combinatorial objects: the strings which parametrize the row-to-row transfer matrix eigenvectors, and the paths which parametrize the corner transfer matrix eigenvectors, can both be expressed in terms of the same set of standard tableaux. Furthermore, the momenta of the strings, th

L. Rozansky

We formulate a conjecture about the structure of `upper lines' in the expansion of the colored Jones polynomial of a knot in powers of (q-1). The Melvin-Morton conjecture states that the bottom line in this expansion is equal to the inverse Alexander polynomial of the knot. We conjecture that the upper lines are rational functions whose denominators are

E. L. Bratkovskaya, W. Cassing, U. Mosel

A full calculation of lepton-pair angular characteristics is carried out for $e^+e^-$ pairs created in $p + Be$ and $Ca + Ca$ collisions from 1.0 to 2.1 GeV/A. It is demonstrated that the dilepton decay anisotropy depends sensitively on the different sources and may be used for their disentangling. Due to the dominance of the $η$-and $Δ$-Dalitz decays and on

E. Caurier, F. Nowacki, A. Poves, J. Retamosa

The lifetimes for the double beta decays of $^{76}$Ge, $^{82}$Se and $^{136}$Xe are calculated using very large shell model spaces. The two neutrino matrix elements obtained are in good agreement with the present experimental data. For $<m_ν><1$ eV we predict the following upper bounds to the half-lives for the neutrinoless mode: $T^{(0ν)}_{1/2}(Ge) > 1.85\,

B. K. Jain, Bijoy Kundu

Proton-nucleus collisions, where the beam proton gets excited to the delta resonance and then decays to p$π^+$, either inside or outside the nuclear medium, are studied. Cross-sections for various kinematics for the (p,p$&#39; π^+$) reaction between 500 MeV and 1 GeV beam energy are calculated to see the effects of the nuclear medium on the propagation and d

Jean-Marc Richard

We comment on the proposed measurement of the spin-depolarisation parameter $D_{nn}$ in the strangeness-exchange reaction $\bar{\rm p}{\rm p} \rightarrow \overlineΛΛ$. It is shown that the existing data on the correlation coefficients $C_{ij}$ limit the range allowed for $D_{nn}$.

Charles Radin, Lorenzo Sadun

We give a thorough analysis of those subgroups of SO(3) generated by rotations about perpendicular axes by 2\pi/p and 2\pi/q. A corollary is that such a group is the free product of the cyclic groups of rotations about the separate axes if and only if p,q\ge 3 and are both odd. These groups are naturally associated with a family of hierarchical tilings of Eu

Alok Kumar

In this paper we present a symmetry of a toroidally compactified type II string theory. This symmetry has the interpretaion that it interchanges the left and the right-moving worldsheet coordinates and reverses the orientations of some of the spatial coordinates. We also identify another discrete symmetry of the type II theory which is related to the above o

Vasily E. Tarasov

Quantum mechanics of Hamiltonian (non-dissipative) systems uses Lie algebra and analytic group (Lie group). In order to describe non-Hamiltonian (dissipative) systems in quantum theory we need to use non-Lie algebra and analytic quasigroup (loop). The author derives that analog of Lie algebra for quantum non-Hamiltonian systems is commutant Lie algebra and a

Maxime Kudinov, Peter Orland

A free lattice fermion field theory in 1+1 dimensions can be interpreted as SOS-type model, whose spins are integer-valued. We point out that the relation between these spins and the fermion field is similar to the abelian bosonization relation between bosons and fermions in the continuum. Though on the lattice the connected $2n$-point correlation functions

Claudio Rebbi, Robert Singleton,

We use semiclassical methods to study processes which give rise to change of topology and therefore to baryon number violation in the standard model. We consider classically allowed processes, i.e.~energies above the sphaleron barrier. We develop a computational procedure that allows us to solve the Yang Mills equations of motion for spherically symmetric co

Markus H. Thoma, Christoph T. Traxler

In contrast to the damping of partons in a quark-gluon plasma, the damping of a scalar particle in a hot scalar QED plasma can be calculated to leading order for the whole momentum range using the Braaten-Pisarski method. In this way the evolution of the logarithmic infrared singularity caused by the exchange of a transverse photon from soft to hard momenta

G. Kn&#34;ochlein, S. Scherer, D. Drechsel

We investigate the rare radiative eta decay modes $η\toπ^+π^-γγ$ and $η\toπ^0π^0γγ$ within the framework of chiral perturbation theory at $O(p^4)$. We present photon spectra and partial decay rates for both processes as well as a Dalitz contour plot for the charged decay.

Rob Szalapski

Previous form-factor-based analyses of $e^+e^-\to W^+W^-$ have focused upon non-standard contributions to the $WWZ$ and $WWγ$ vertices. A more complete form-factor-based formalism is presented which allows for more general corrections, including t-channel corrections. The form factors are then calculated from an effective Lagrangian. Because the existence or

Rob Szalapski

Effective theories provide a powerful tool for testing the Standard Model and for searching for the effects of new physics in a model-independent manner. In general one assumes that the effects of new physics characterized by a high-energy scale may be observed at low-energies only through quantum corrections. These quantum corrections may be described by ef

M. Beneke, G. Buchalla

We investigate the total inclusive decay rate of the (ground state) $B_c$ meson within the framework of an operator product expansion in inverse powers of the heavy quark masses and subsequent matching onto nonrelativistic QCD. The expansion is organized as a series in the strong coupling and in powers of the heavy quark velocities in the $B_c$, reflecting t

M. Goeckeler, R. Horsley, E. -M. Ilgenfritz, H. Oelrich

We review our progress on the lattice calculation of low moments of both the unpolarised and polarised nucleon structure functions.

F. Abe

We present the result of a search for charged Higgs decays of the top quark, produced in $p\bar{p}$ collisions at $\surd s =$ 1.8 TeV. When the charged Higgs is heavy and decays to a tau lepton, which subsequently decays hadronically, the resulting events have a unique signature: large missing transverse energy and the low-charged-multiplicity tau. Data coll

Vivek Jain

In this talk, I present new results from CLEO on charm and bottom hadrons. Most of the talk will be on the issue of the B semileptonic branching fraction, its connection to the number of charm quarks produced in the decay of a b quark, and the rate for the b -> ccbars transition

Darío Núñez, Hernando Quevedo, Daniel Sudarsky

We show that in all theories in which black hole hair has been discovered, the region with non-trivial structure of the non-linear matter fields must extend beyond 3/2 the horizon radius, independently of all other parameters present in the theory. We argue that this is a universal lower bound that applies in every theory where hair is present. This {\it no

Viktor Ginzburg, Victor Guillemin, Yael Karshon

We announce the following result and give several applications: A Hamiltonian $T$-space (for $T$ a torus) with isolated fixed points is cobordant to a disjoint union of weighted projective spaces which are constructed from its fixed point data. The applications concern the Duistermaat-Heckman formula, the topological Jeffrey-Kirwan localization theorem, and

M. de Sousa Vieira, H. J. Herrmann

A simple growth model for DNA evolution is introduced which is analytically solvable and reproduces the observed statistical behavior of real sequences.

Dror Orgad, Shimon Levit

We consider the process of parametric excitation of gapless edge modes in a Hall bar by an alternating current. We find that such a process can be realized provided both an inter-edge interaction and a constant current are present in the bar. The expected experimental signatures of this phenomenon are discussed.

A. A. Esin, R. Narayan, E. Ostriker, I. Yi

We describe hot, optically-thin solutions for one-temperature accretion disks around black holes. We include cooling by synchrotron, bremsstrahlung, and Comptonization. Our solutions are thermally and viscously stable, with gas temperatures on the order of $T \sim 10^9-10^{10.7}$K. The thermal stability is a direct result of the inclusion of synchrotron cool

Rohan Mahadevan, Ramesh Narayan, Insu Yi

We present a complete solution to the cyclotron-synchrotron radiation due to an isotropic distribution of electrons moving in a magnetic field. We make no approximations in the calculations other than artificially broadening the harmonics by a small amount in order to facilitate the numerics. In contrast to previous calculations, we sum over all relevant har

Harvey B. Richer, William E. Harris, Gregory G. Fahlman, Roger A. Bell

We establish a framework for determing absolute ages of Galactic globular clusters and then use these ages to investigate the age-metallicity and age-Galactocentric distance relations for the 36 clusters with the most reliable age data. The clusters span Galactocentric distances from 4 through 100 kpc and cover a metallicity range from $[Fe/H] = -0.6$ to $-2

Philip D. Mannheim

We show that within the cosmology associated with conformal gravity the age of the universe is given as $1/H_0$, to thus overcome the current cosmological age crisis. We show that while the parameter $Ω_{mat} = ρ_{mat} / ρ_C$ takes on all values between zero and infinity in conformal gravity, nonetheless it is of order one (but not identically equal to one)

P. Stein

An extensive redshift survey has been conducted on a sample of 15 nearby (0.01 < z < 0.05) clusters of galaxies. A total number of 860 redshifts were determined by fitting of emission--lines and/or cross-correlation techniques. Of this sample, 735 galaxies are within 0.2--0.8 Mpc ($H_0$ = 50 km/s/Mpc) of the center of clusters. Approximate morphological type

T. R. Bedding, H. Kjeldsen, J. Reetz, B. Barbuy

Kjeldsen et al. (1995, AJ 109, 1313; astro-ph/9411016) have developed a new technique for measuring stellar oscillations and claimed a detection in the G subgiant eta Boo. The technique involves monitoring temperature fluctuations in a star via their effect on the equivalent width of Balmer lines. In this paper we use synthetic stellar spectra to investigate

C. L. Bennett, A. Banday, K. M. Gorski, G. Hinshaw

The cosmic microwave background radiation provides unique constraints on cosmological models. In this Letter we present a summary of the spatial properties of the cosmic microwave background radiation based on the full 4 years of COBE DMR observations, as detailed in a set of companion Letters. The anisotropy is consistent with a scale-invariant power law mo

A. Kogut, A. J. Banday, C. L. Bennett, K. M. Gorski

The Differential Microwave Radiometers (DMR) instrument aboard the Cosmic Background Explorer (COBE) has mapped the full microwave sky to mean sensitivity 26 uK per 7 deg field of view. The absolute calibration is determined to 0.7% with drifts smaller than 0.2% per year. We have analyzed both the raw differential data and the pixelized sky maps for evidence

A. J. Banday, K. M. Gorski, C. L. Bennett, G. Hinshaw

The sky-RMS is the simplest model-independent characterization of a cosmological anisotropy signal. The RMS temperature fluctuations determined from the $COBE$-DMR four-year sky maps are frequency independent, consistent with the hypothesis that they are cosmological in origin, with a typical amplitude at 7 degrees of ~ 35 \pm\ 2 uK and at 10 degrees of ~29

A. J. Banday, K. M. Gorski, C. L. Bennett, G. Hinshaw

We limit the possible contributions from non-cosmological sources to the COBE-DMR four-year sky maps. The DMR data are cross-correlated with maps of rich clusters, extragalactic IRAS sources, HEAO-1 A-2 X-ray emission and 5 GHz radio sources using a Fourier space technique. There is no evidence of significant contamination by such sources at an rms level of

K. M. Gorski, A. J. Banday, C. L. Bennett, G. Hinshaw

Fourier analysis and power spectrum estimation of the cosmic microwave background anisotropy on an incompletely sampled sky developed by Gorski (1994) has been applied to the high-latitude portion of the 4-year COBE DMR 31.5, 53 and 90 GHz sky maps. Likelihood analysis using newly constructed Galaxy cuts (extended beyond |b| = 20deg to excise the known foreg

A. Kogut, A. J. Banday, C. L. Bennett, K. Gorski

We search the high-latitude portion of the COBE Differential Microwave Radiometers (DMR) 4-year sky maps for evidence of a non-Gaussian temperature distribution in the cosmic microwave background. The genus, 3-point correlation function, and 2-point correlation function of temperature maxima and minima are all in excellent agreement with the hypothesis that

G. Hinshaw, A. J. Banday, C. L. Bennett, K. M. Gorski

The 2-point temperature correlation function is evaluated from the 4-year COBE DMR microwave anisotropy maps. We examine the 2-point function, which is the Legendre transform of the angular power spectrum, and show that the data are statistically consistent from channel to channel and frequency to frequency. The most likely quadrupole normalization is comput

A. Kogut, G. Hinshaw, A. J. Banday, C. L. Bennett

We use the COBE Differential Microwave Radiometers (DMR) 4-year sky maps to model Galactic microwave emission at high latitudes (|b| > 20 deg). Cross-correlation of the DMR maps with Galactic template maps detects fluctuations in the high-latitude microwave sky brightness with the angular variation of the DIRBE far-infrared dust maps and a frequency dependen

E. L. Wright, C. L. Bennett, K. Gorski, G. Hinshaw

The angular power spectrum estimator developed by Peebles (1973) and Hauser & Peebles (1973) has been modified and applied to the 4 year maps produced by the COBE DMR. The power spectrum of the observed sky has been compared to the power spectra of a large number of simulated random skies produced with noise equal to the observed noise and primordial density

G. Hinshaw, A. J. Banday, C. L. Bennett, K. M. Gorski

We employ a pixel-based likelihood technique to estimate the angular power spectrum of the COBE Differential Microwave Radiometer (DMR) 4-year sky maps. The spectrum is consistent with a scale-invariant power-law form with a normalization, expressed in terms of the expected quadrupole anisotropy, of Q_{rms-PS|n=1} = 18 +/- 1.4 uK, and a best-fit spectral ind

Elizabeth Gasparim

In this paper we study holomorphic rank two vector bundles on the blow up of $ {\bf C}^2$ at the origin. A classical theorem of Birchoff and Grothendieck says that any holomorphic vector bundle on the projective plane ${\bf P}^1$ splits into a sum of line bundles. If $E$ is a holomorphic vector bundle over the blow up of $ {\bf C}^2$ at the origin, then the

S. S. Gubser, A. Hashimoto, I. R. Klebanov, J. M. Maldacena

The scattering of R-R gauge bosons off of Dirichlet p-branes is computed to leading order in the string coupling. The results are qualitatively similar to those found in the scattering of massless NS-NS bosons: all p-branes with p >= 0 exhibit stringy properties, in particular the Regge behavior. Both the R-R and NS-NS scattering amplitudes agree in the limi

E. Corrigan

The purpose of this talk is to address a couple of simple-sounding questions: what boundary conditions are compatible with (a) Classical integrability? (b) Quantum integrability?

H. David Politzer

The computer code on which this paper relied contained an error. When corrected, the Monte Carlo evaluation of the ground state occupation is consistent with the conventional grand canonical calculation. Hence, the original version of this paper has been withdrawn.

Nobuyuki Sakai

We consider the classical fluctuations of the gravitational constant generated by bubbles in the inflationary universe. For extended inflation, we demonstrate numerically how and how large fluctuations are produced during bubble expansion. The amplitude of the fluctuations depends on the Brans-Dicke parameter $ω$: if $ω$ is of the order of unity, the amplitu

M. T. Hussein, N. M. Hassan

The hadronic quark structure is investigated in the frame of high energy electron proton scattering. A phenomenological model based on the Born approximation is used to calculate the transition matrix element for the quark system forming the proton target. A potential of electromagnetic nature is assumed for the calculation of the multiple scattering of elec

D. Espriu, A. Travesset

We apply Monte Carlo Renormalization group to the crumpling transition in random surface models of fixed connectivity. This transition is notoriously difficult to treat numerically. We employ here a Fourier accelerated Langevin algorithm in conjunction with a novel blocking procedure in momentum space which has proven extremely successful in $λϕ^4$. We perfo

F. Guil, M. Mañas

The plane wave solutions of the three-wave resonant interaction in the plane are considered. It is shown that rank-one constraints over the right derivatives of invertible operators on an arbitrary linear space gives solutions of the three-wave resonant interaction that can be understood as a Darboux transformation of the plane wave solutions. The method is

A. Stern, I. Yakushin

We examine a two-parameter ($\hbar ,$ $λ$) deformation of the Poincarè algebra which is covariant under the action of $SL_q(2,C).$ When $λ\rightarrow 0$ it yields the Poincarè algebra, while in the $\hbar\rightarrow 0$ limit we recover the classical quadratic algebra discussed previously in \cite{ssy95}, \cite{sy95}. The analogues of the Pauli-Lubanski vecto

J. A. de Azcarraga, A. M. Perelomov, J. C. Perez Bueno

New generalized Poisson structures are introduced by using suitable skew-symmetric contravariant tensors of even order. The corresponding `Jacobi identities&#39; are provided by conditions on these tensors, which may be understood as cocycle conditions. As an example, we provide the linear generalized Poisson structures which can be constructed on the dual s

Luis Paris

Let $(W,S)$ be a Coxeter system, and let $X$ be a subset of $S$. The subgroup of $W$ generated by $X$ is denoted by $W_X$ and is called a parabolic subgroup. We give the precise definition of the commensurator of a subgroup in a group. In particular, the commensurator of $W_X$ in $W$ is the subgroup of $w$ in $W$ such that $wW_Xw^{-1}\cap W_X$ has finite ind

Antal Jevicki, Andre van Tonder

We present a simple physical representation for states of the two-dimensional string theory. In order to incorporate a fundamental cutoff of the order 1/g we use a picture consisting of q-oscillators at the first-quantized level. In this framework we also find a representation for the (singular) negatively dressed states representing nontrivial string backgr

Matthias Doerrzapf

Using explicit expressions for a class of singular vectors of the $N=2$ (untwisted) algebra and following the approach of Malikov-Feigin-Fuchs and Kent, we show that the analytically extended Verma modules contain two linearly independent neutral singular vectors at the same grade. We construct this two dimensional space and we identify the singular vectors

Abhay Ashtekar

Over the last two years, the canonical approach to quantum gravity based on connections and triads has been put on a firm mathematical footing through the development and application of a new functional calculus on the space of gauge equivalent connections. This calculus does not use any background fields (such as a metric) and is thus well-suited to a fully

K. Arthur, D. H. Tchrakian

Vector $SO(3)$ gauged $O(4)$ sigma models on $\R_3$ are presented. The topological charge supplying the lower bound on the energy and rendering the soliton stable coincides with the Baryon number of the Skyrmion. These solitons have vanishing magnetic monopole flux. To exhibit the existence of such solitons, the equations of motion of one of these models is

Giovanni Amelino-Camelia, Chaiho Rim

The 3-anyon problem is studied using a set of variables recently proposed in an anyon gauge analysis by Mashkevich, Myrheim, Olaussen, and Rietman (MMOR). Boundary conditions to be satisfied by the wave functions in order to render the Hamiltonian self-adjoint are derived, and it is found that the boundary conditions adopted by MMOR are one of the ways to sa

M T Batchelor, V Fridkin, A Kuniba, Y K Zhou

We present new diagonal solutions of the reflection equation for elliptic solutions of the star-triangle relation. The models considered are related to the affine Lie algebras $A_n^{(1)},B_n^{(1)},C_n^{(1)},D_n^{(1)}$ and $A_n^{(2)}$. We recover all known diagonal solutions associated with these algebras and find how these solutions are related in the ellipt

Ralph Blumenhagen, Andreas Wisskirchen

We investigate the subset of exactly solvable (0,4) world sheet supersymmetric string vacua contained in a recent class of Gepner-like (0,2) superconformal models. The identification of these models with certain points of enhanced gauge symmetry on K_3 x T_2 can be achieved completely. Furthermore, we extend the construction of in general (0,2) supersymmetri

Takeo Inami, Satoru Odake, Yao-Zhong Zhang

We derive and classify all solutions of the boundary Yang-Baxter equation (or the reflection equation) for the 19-vertex model associated with $U_q(\widehat{sl_2})$. Integrable $XXZ$ spin-1 chain hamiltonian with general boundary interactions is also obtained.

Chi-Keung Chow

In a previous article, it has been proved under the framework of chiral soliton model that the same Isgur--Wise form factor describes the semileptonic $Λ_b\toΛ_c$ and $Σ^{(*)}_b\toΣ^{(*)}_c$ decays in the large $N_c$ limit. It is shown here that this result is in fact independent of the chiral soliton model and is solely the consequence of the spin-flavor SU

H. Heiselberg, Xin-Nian Wang

Thermalization in an expanding parton plasma is studied within the framework of Boltzmann equation in the absence of any mean fields. In particular, we study the time-dependence of the relaxation time to the lowest order in finite temperature QCD and how such time-dependence affects the thermalization of an expanding parton plasma. Because of Debye screening

Ch. Ritter, B. C. Metsch, C. R. Munz, H. R. Petry

We show that instanton effects may play a crucial role in the decay of scalar mesons into two pseudoscalars. Particularly the branching ratios of two meson decays of the $f_0(1500)$, which is considered as a glue-ball candidate, are then compatible with an ordinary $q \bar{q}$-structure of this resonance and a small positive SU(3) mixing angle, close to a re

Joerg Schaldach, Peter Sieber, Dmitri Diakonov, Klaus Goeke

High-density fermion matter is meta-stable due to the anomalous non-conservation of baryon and lepton numbers in the electroweak theory. The meta-stable state decays by penetrating the sphaleron barrier separating topologically different vacua. The decay happens locally, and results in an annihilation of twelve fermions, accompanied by a production of gauge

S. D. Bass

The Drell-Hearn-Gerasimov sum-rule is really two sum-rules: one for each of the valence and the sea/glue contributions to the nucleon wavefunction. The convergence of these sum-rules follows from the Froissart bound for spin dependent processes in QCD and is necessary for the consistency of the constituent quark model of low energy QCD. Some challenges for f

P. Binétruy, S. Lavignac, P. Ramond

The observed hierarchy of quark and lepton masses and mixings may be obtained by adding an abelian family symmetry to the Minimal Supersymmetric Model and coupling quarks and leptons to an electroweak singlet scalar field. In a large class of such models, this symmetry suffers from anomalies which must be compensated by the Green-Schwarz mechanism; this in t

T. Gousset, H. J. Pirner

We calculate the ratio of gluon densities, G^Sn(x)/G^C(x), for 0.01<x<0.1, from the new high statistics data on F_2^Sn/F_2^C taken by the NM Collaboration. For small x, the shadowing in the gluon distribution is about equal to the shadowing of quark distribution. The antishadowing in the gluon distribution, however, is roughly 10%. We also compare with the r

Hans Peter Nilles

In string theory the coupling parameters are functions of moduli fields. The actual values of the coupling constants are then dynamically determined through the vacuum expextation values of these fields. We review the attempts to connect such theories to low energy effective field theories with realistic gauge coupling constants. This includes a discussion o

R. D. Peccei

This summary discusses some of the topics which were of overarching interest at the Symposium. These included, corrections to perturbative QCD predictions; heavy quark physics; electroweak symmetry breaking; and physics of the top quark.

R. Janik, J. Wosiek

It is pointed out that the recently discovered analogy between the QCD description of the Pomeron exchange and the Heisenberg chain may allow to apply lattice techniques to the high energy phenomena.

A. Cruz, L. A. Fernandez, D. Iniguez, A. Tarancon

We have made a study of several update algorithms using the XY model. We find that sequential local overrelaxation is not ergodic at the scale of typical Monte Carlo simulation time. We have introduced a new multisite microcanonical update method, which yields results compatible with those of random overrelaxation and the microcanonical demon algorithm, whic

Douglas M. Eardley, Eric W. Hirschmann

In a recent Physical Review Letter, Wilson and Mathews presented some interesting numerical calculations of a system of two equally massive neutron stars in strong-field gravity. In particular they estimated the innermost stable circular orbit in their system. Here we point out a possibly important consequence of their results: Their calculated configuration

M. Vasilic, T. Vukasinac

The properties of gravitational kinks are studied within some simple models of two dimensional gravity. In spacetimes of cylindrical topology we prove the existence of kinks of constant curvature with arbitrary kink numbers. In $R^1\times R^1$ spacetimes $m=1$ kink solutions of the equation $R=0$ are found, whereas $|m|>1$ flat kinks are proved not to exist.

T. P. Devereaux

The role of symmetry of the inelastic light scattering amplitude, the superconducting energy gap, and the underlying Fermi surface manifold on the Raman spectra of unconventional superconductors is discussed in detail. Particular emphasis is placed on both single and bi-layer superconductors. It is found that the $B_{1g}$ channel may be the most sensitive to

A. Mosk, Th. M. Nieuwenhuizen, C. Barnes

Wave propagation through waveguides, quantum wires or films with a modest amount of disorder is in the semi-ballistic regime when in the transversal direction(s) almost no scattering occurs, while in the long direction(s) there is so much scattering that the transport is diffusive. For such systems randomness is modelled by an inhomogeneous density of point-

K. Okano, L. Schuelke, K. Yamagishi, B. Zheng

Numerically we simulate the short-time behaviour of the critical dynamics for the two dimensional Ising model and Potts model with an initial state of very high temperature and small magnetization. Critical initial increase of the magnetization is observed. The new dynamic critical exponent $θ$ as well as the exponents $z$ and $2β/ν$ are determined from the

A. A. Kipchatov, L. V. Krasichkov

The method of generating of high-dimensional oscillations on the basis of summing of low-dimensional chaotic signals of noncoupled dynamical systems is investigated. It is shown that the correlation dimension of attractor reconstructed from such oscillations is equal to the sum of dimensions of the original signals. The possibilities for obtaining of homogen

Per Dahlqvist

We show that Lyapunov exponent for the Sinai billiard is $λ= -2\log(R)+C+O(R\log^2 R)$ with $C=1-4\log 2+27/(2π^2)\cdot ζ(3)$ where $R$ is the radius of the circular scatterer. We consider the disk-to-disk-map of the standard configuration where the disks is centered inside a unit square.

Dieter H. Hartmann, Michael S. Briggs, Karl Mannheim

The angular distribution of GRBs is isotropic, while the brightness distribution of bursts shows a reduced number of faint events. These observations favor a cosmological burst origin. If GRBs are indeed at cosmological distances and if they trace luminous matter, we must eventually find an anisotropic distribution of bright bursts. If a significant number o

Abraham Loeb, Arthur Kosowsky

The existence of a primordial magnetic field at the last scattering surface may induce a measurable Faraday rotation in the polarization of the cosmic microwave background. We calculate the magnitude of this effect by evolving the radiative transfer equations for the microwave background polarization through the epoch of last scatter, in the presence of a ma

Ofer Lahav

Three galaxy redshifts surveys and their analyses are discussed. (i) The recently completed Optical Redshift Survey (ORS) includes galaxies larger than 1.9 arcmin and/or brighter than $14.5^m$. It provides redshifts for $\sim 8300 $ galaxies at Galactic latitude $|b|>20^o$. A new analysis of the survey explores the existence and extent of the Supergalactic P

J. Kaluzny, M. Kubiak, M. Szymanski, A. Udalski

Three fields covering the central part of the globular cluster Omega Cen were surveyed in a search for variable stars. We present V-band light curves for 22 periodic variables: 9 SX~Phe stars, 7 contact binaries, 5 detached or semi-detached binaries, and one spotted variable (FK Com or RS CVn type star). Only 2 of these variables were previously known. All S

J. Kaluzny

The central part of the globular cluster NGC 288 was surveyed in a search for short-period variable stars. We obtained the V-band light curves for 4 SX Phe stars and 2 RR Lyrae variables, five of which are new discoveries. All SX Phe stars belong to blue stragglers. We present a color-magnitude diagram including stars from the tip of red giant branch to the

C A Jackson

Previous analyses of the space densities of extragalactic radio sources have proceeded on the assumption of two populations: flat-spectrum and steep-spectrum objects, compact and extended in radio structure respectively. It is now generally believed that anisotropic radiation and relativistic beaming effects mean that the steep-spectrum objects are the flat-

G. Parzen

This paper studies the particle motion when the tune is in the stable region close to the edge of linear sum resonance stopband. Results are found for the tune and the beta functions. Results are also found for the two solutions of the equations of motion. The results found are shown to be also valid for small accelerators where the large accelerator approxi

J. R. Wilson, G. J. Mathews, P. Marronetti

We describe a numerical method for calculating the (3+1) dimensional general relativistic hydrodynamics of a coalescing neutron-star binary system. The relativistic field equations are solved at each time slice with a spatial 3-metric chosen to be conformally flat. Against this solution to the general relativistic field equations the hydrodynamic variables a

Barbara Drossel

Certain systems with slow driving and avalanche-like dissipation events are naturally close to a critical point when the ratio of two energy scales is large. The first energy scale is the threshold above which an avalanche is triggered, the second scale is the threshold above which a site is affected by an avalanche. I present results of computer simulations

S. Nishigaki

Wilson&#39;s approximation scheme of RG recursion formula dropping momentum dependence of the propagators is applied to large-$N$ vector and matrix models in dimensions $2<d<4$ by making use of their exact solutions in zero dimension. In spite of apparent dependence of critical exponents upon the dilatational parameter $ρ$ involved by the approximation, the

George Leibbrandt, Jimmy Williams

A new procedure for regularizing Feynman integrals in the noncovariant Coulomb gauge is proposed for Yang-Mills theory. The procedure is based on a variant of dimensional regularization, called split dimensional regularization, which leads to internally consistent, ambiguity-free integrals. It is demonstrated that split dimensional regularization yields a on

David A. Buote, Claude R. Canizares

We present spatial analysis of the deep (57ks) ROSAT HRI X-ray image of the E4 galaxy NGC 720. The orientation of the HRI surface brightness is consistent with the optical position angle $(PA)$ interior to semi-major axis $a\sim 60\arcsec$ (optical $R_e\sim 50\arcsec$). For larger $a$ the isophotes twist and eventually $(a\gtrsim 100\arcsec)$ orient along a

Jan C. Plefka

In this thesis generalizations of matrix and eigenvalue models involving supersymmetry are discussed. Following a brief review of the Hermitian one matrix model, the c=-2 matrix model is considered. Built from a matrix valued superfield this model displays supersymmetry on the matrix level. We stress the emergence of a Nicolai-map of this model to a free Her

Tadashi Kadowaki, Yoshihiko Nonomura, Hidetoshi Nishimori

We propose a new method for exact analytical calculation of the ground-state energy of the Ising spin glass on strips. An outstanding advantage of this method over the numerical transfer matrix technique is that the energy is obtained for complex values of the probability describing quenched randomness. We study the $\pm J$ and the site-random models using t

Z. Horvath, G. Takacs

We continue the investigation of massive integrable models by means of the bootstrap fusion procedure, started in our previous work on O(3) nonlinear sigma model. Using the analogy with SU(2) Thirring model and the O(3) nonlinear sigma model we prove a similar relation between sine-Gordon theory and a one-parameter deformation of the O(3) sigma model, the sa

Peter Schneider

The distortion of images of faint background galaxies by (weak) gravitational lensing can be used to measure the mass distribution of the deflector. The image distortions can be used to define a weighted mean of the mass inside a circular aperture, as was first suggested by Kaiser. The aperture mass can be used to {\it detect} dark matter concentrations. Kee

A. V. Dotsenko, O. P. Sushkov

We study the behaviour of the electronic chemical potential in YBa2Cu3O near the superconducting transition using the spin-wave exchange theory of pairing. We find that the experimental value of the jump in the temperature derivative of the chemical potential is inconsistent with the theoretical value calculated under the assumption of constant hole concentr