September 1996 arXiv papers — page 6

John D. Larwood, John C. B. Papaloizou

In this paper we present an analytical and numerical study of the response of a circumbinary disc subject to the tidal-forcing of a binary with a fixed circular orbit. We consider fluid discs with a range of thicknesses and binaries with a range of mass ratios, orbital separations and inclination angles. Our numerical simulations are implemented using a SPH

Edward B. Jenkins, Antonio Peimbert

Lyman and Werner band absorption features from interstellar molecular hydrogen in rotational levels J = 0, 1, 2, 3 and 5 were observed in the spectrum of zeta Ori A by the Interstellar Medium Absorption Profile Spectrograph (IMAPS). Most of the molecules are found in two distinct velocity components, with one of them showing profile shapes that become broade

N. Zacharias

Sets of short exposure, guided CCD frames are used to measure the noise added by the atmosphere to differential astrometric observations. Large nightly variations that are correlated with the seeing have been found in the data obtained over 2 years at the KPNO and CTIO 0.9-meter telescopes. The rms noise added by the atmosphere, after a linear transformation

M. Plionis, E. Branchini, I. Zehavi, A. Dekel

We compare the predicted Abell/ACO cluster density and velocity fields, using linear theory, with that based on the MarkIII catalog and the POTENT machinery within 7000 km/sec. Both density & velocity fields are in good qualitative agreement indicating that apart from a linear biasing factor the optical Abell/ACO clusters do trace the underlying mass distrib

Mikael Sahrling

We consider the effect of Hall-drift on the evolution of magnetic fields in neutorn star crusts using a finite difference code. Previously, most studies have focused on the situation where the ohmic term dominates the evolution. Here, we investigate the case where the ohmic term is small compared to the Hall term. We show that the effect on the magnetic fiel

J. Franco, G. Garcia-Segura, T. Plewa

Here we discuss the interaction of massive stars with their parental molecular clouds. A summary of the dynamical evolution of HII regions and wind-driven bubbles in high-pressure cloud cores is given. Both ultracompact HII regions and ultracompact wind-driven bubbles can reach pressure equilibrium with their surrounding medium. The structures stall their ex

Kieran O'Grady

This is a survey paper: we discuss certain recent results, with some improvements. It will appear in the S. Cruz proceedings.

Sidney van den Bergh

Current ideas on the formation of the Galaxy are reviewed. Many of the observed characteristics of our Milky Way System are consistent with a scenario in which the Galaxy formed inside out, with the inner part of it evolving by rapid collapse of a single protogalaxy, while the outer halo was accreted over an extended period. A number of possible problems wit

Craig J. Hogan, Scott F. Anderson, Martin H. Rugers

We present a new, high resolution HST/GHRS spectrum of quasar Q0302-003, and use the HeII Lyman-$α$ absorption, together with a high resolution Keck spectrum of the HI Lyman-$α$ forest, to probe the distribution and ionization state of foreground gas just below the quasar redshift $z\approx 3.3$. The main new conclusions from the current data are: 1. The HeI

Joshua Feinberg, A. Zee

We consider random Hermitian matrices made of complex or real $M\times N$ rectangular blocks, where the blocks are drawn from various ensembles. These matrices have $N$ pairs of opposite real nonvanishing eigenvalues, as well as $M-N$ zero eigenvalues (for $M>N$.) These zero eigenvalues are ``kinematical" in the sense that they are independent of randomn

O. Richard, S. Vauclair

We have computed solar models similar to those published in Richard, Vauclair, Charbonnel, Dziembowski (1996), in which we have added local mixing near the solar core in order to decrease the neutrino production. The results show that the neutrino fluxes are reduced as expected (although not enough to account for the observed values), but the obtained models

K. G. Chetyrkin, J. H. Kuhn, T. Teubner

The total cross section for electron-positron annihilation into hadrons is calculated in the region just below the B meson threshold. QCD corrections up to third order, quark mass effects, initial state radiation, the running of alpha_QED and the tails of the Upsilon resonances are included in the prediction. For given alpha_s the prediction is accurate to 0

D. A. Trifonov

A complete set of solutions |z,u,v>_{sa} of the eigenvalue equation (ua^2+va^{dagger 2})|z,u,v> = z|z,u,v> ([a,a^{dagger}]=1) are constructed and discussed. These and only these states minimize the Schrödinger uncertainty inequality for the squared amplitude (s.a.) quadratures. Some general properties of Schrödinger intelligent states (SIS) |z,u,v> for any t

A. Avakyan, T. Hakobyan, A. Sedrakyan

We construct the family of spin chain Hamiltonians, which have affine quantum group symmetry. Their eigenvalues coincide with the eigenvalues of the usual spin chain Hamiltonians, but have the degeneracy of levels, corresponding to affine quantum group. The space of states of these spin chains is formed by the tensor product of fully reducible representation

Subir Sachdev, A. P. Young

We present asymptotically exact results for the real time order parameter correlations of a class of d=1 Ising models in a transverse field at low temperatures (T) on both sides of the quantum critical point. The correlations are a product of a T-independent factor determined by quantum effects, and a T-dependent relaxation function which comes from a classi

Chun Liu

Some phenomenological aspects of a supersymmetric model for fermion mass hierarchy proposed previously are discussed. It is required that the lepton universality violation is near to its current experimental bound. The lepton number violation decay modes $τ\to 2eμ$ and $3μ$ maybe observable in the near future. The Majorana mass of electron-neutrino is predic

H. J. de Vega, N. S'anchez, F. Combes

We develop a field theoretical approach to the cold interstellar medium (ISM). We show that a non-relativistic self-gravitating gas in thermal equilibrium with variable number of atoms or fragments is exactly equivalent to a field theory of a single scalar field ϕ({\vec x}) with exponential self interaction.We analyze this field theory perturbatively and non

Martin Luescher, Stefan Sint, Rainer Sommer, Peter Weisz

The coefficients multiplying the counterterms required for O($a$) improvement of the action and the isovector axial current in lattice QCD are computed non-perturbatively, in the quenched approximation and for bare gauge couplings $g_0$ in the range $0 \leq g_0 \leq 1$. A finite-size method based on the Schrödinger functional is employed, which enables us to

X. Hu, Franco Nori

We study squeezed quantum states of phonons, which allow the possibility of modulating the quantum fluctuations of atomic displacements below the zero-point quantum noise level of coherent phonon states. We calculate the corresponding expectation values and fluctuations of both the atomic displacement and the lattice amplitude operators, and also investigate

Lian Zheng, M. W. Ortalano, S. Das Sarma

We consider various exchange-driven electronic instabilities in semiconductor double-layer systems in the absence of any external magnetic field. We establish that there is no exchange-driven bilayer to monolayer charge transfer instability in the double-layer systems. We show that, within the unrestricted Hartree-Fock approximation, the low density stable p

Tatsuo Yanagita, Kunihiko Kaneko

A coupled map model for cloud dynamics is proposed, which consists of the successive operations of the physical processes; buoyancy, diffusion, viscosity, adiabatic expansion, fall of a droplet by gravity, descent flow dragged by the falling droplet, and advection. Through extensive simulations, the phases corresponding to stratus, cumulus, stratocumulus and

Asher Peres

A quantum system consisting of two subsystems is separable if its density matrix can be written as $ρ=\sum w_K ρ_K'\otimes ρ_K''$, where $ρ_K'$ and $ρ_K''$ are density matrices for the two subsytems, and the positive weights $w_K$ satisfy $\sum w_K=1$. A necessary condition for separability is derived and is shown to be more sensitive

Steven Duplij

Supersymmetry contains initially noninvertible objects, but it is common to deal with the invertible ones only, factorizing former in some extent. We propose to reconsider this ansatz and try to redefine such fundamental notions as supermanifolds, fiber bundles and homotopies using some weakening invertibility conditions. The prefix semi- reflects the fact t

Timothy J. Hodges, Thierry Levasseur, Margarita Toro

Multi-parameter versions U_p(g) and C_p[G] of the standard quantum groups U_q(g) and C_q[G] are considered where G is a semi-simple connected complex algebraic group and g is the Lie algebra of G. The primitive spectrum of C_p[G] is calculated, generalizing a result of Joseph for the standard quantum groups. This classification is compared with the classific

M. S. Fayache, L. Zamick, Y. Y. Sharon

We carry out a study of the study of the $Q \cdot Q$ interaction in a model space which consists of several nucleons in an open shell and all $2 \hbar ω$ excitations. This interaction is $ -t (X_o/2) Q \cdot Q$, where for t=1 we get the `accepted strength'. In the $0p$ space, the spectrum would scale with $t$. In this space, the $2^+_1$ and $2^+_2$ state

Michael Buballa

We reinvestigate the conditions for stable matter solutions in the Nambu--Jona-Lasinio (NJL) model. In mean field approximation the NJL model can be regarded as an extension of the Walecka mean field model to include negative energy fermion states. While this extension is necessary to allow for a chiral phase transition, it was found some time ago that at th

Michio Honma, Takahiro Mizusaki, Takaharu Otsuka

The feasibility of shell-model calculations is radically extended by the Quantum Monte Carlo Diagonalization method with various essential improvements. The major improvements are made in the sampling for the generation of shell-model basis vectors, and in the restoration of symmetries such as angular momentum and isospin. Consequently the level structure of

Antoni Szczurek, Alfons J. Buchmann, Amand Faessler

We discuss the dressing of constituent quarks with a pseudoscalar meson cloud within the effective chiral quark model. SU(3) flavor symmetry breaking effects are included explicitly. Our results are compared with those of the traditional meson cloud approach in which pions are coupled to the nucleon. The pionic dressing of the constituent quarks explains the

H. Herndl, R. Hofinger, P. Mohr, H. Oberhummer

Neutron capture by neutron-rich Li- and Be-isotopes plays a role in big--bang nucleosynthesis, especially in its inhomogeneous version and in the $α$--process occurring in supernovae. New reaction rates for $^{7,8}$Li(n,$γ$)$^{8,9}$Li and $^{9,10,11}$Be(n,$γ$)$^{10,11,12}$Be have been consistently calculated using direct capture for the nonresonant part and

F. A. Lunev

Simple bosonic path integral representation for path ordered exponent is derived. This representation is used, at first, to obtain new variant of non-Abelian Stokes theorem. Then new pure bosonic worldline path integral representations for fermionic determinant and Green functions are presented. Finally, applying stationary phase method, we get quasiclassica

Konstadinos Sfetsos

String propagation on a curved background defines an embedding problem of surfaces in differential geometry. Using this, we show that in a wide class of backgrounds the classical dynamics of the physical degrees of freedom of the string involves 2-dim sigma-models corresponding to coset conformal field theories.

J. A. Gracey

We review the application of the critical point large N_f self-consistency method to QCD. In particular we derive the O(1/N_f) d-dimensional critical exponents whose epsilon-expansion determines the perturbative coefficients in MSbar of the field dimensions, beta-function and various twist-2 operators which occur in the operator product expansion of deep ine

Masayuki Noguchi

We study mirror symmetry of Calabi-Yau manifolds within the framework of the Gauss-Manin system. Applying the flat coordinates to the Gauss-Manin system for the periods, we derive differential equations for the mirror map in addition to the ordinary Picard-Fuchs equations for the periods. These equations are obtained for a class of one-parameter models and a

S. J. Brodsky

There are many outstanding discrepancies comparing the predictions of perturbative QCD and measurements of the rate of production and decay of heavy quark systems. The problems include the $J/ψ\to ρπ$ puzzle, leading charmed particle effects, the anomalous behavior of the heavy quark sea components of structure functions, anomalous nuclear target effects, an

Robert D. Pisarski, Michel Tytgat

At finite temperature, the Nambu-Goldstone bosons of a spontaneously broken chiral symmetry travel at a velocity $v < 1$. This effect first appears at order $\sim T^4$ in an expansion about low temperature, and can be related to the appearence of two distinct pion decay constants in a thermal bath. We discuss some consequences on the thermodynamics of a gas

Thomas G. Rizzo

We explore the capability of the Tevatron and LHC as well as other future hadron colliders to place limits on the possible existence of flavor-independent $q \bar q γγ$ contact interactions which can lead to an excess of high $p_t$ diphoton events with large invariant masses. Constraints on the corresponding $e^+e^-γγ$ contact interaction already exist from

J. A. Gracey

We report on the progress in the computation of the beta-functions of phi^4 theory and QCD in the large N expansion. For the former we give an analytic formula for the critical exponent which encodes higher order coefficients in the series beyond those currently known in the MSbar scheme at O(1/N^2) in a large N expansion. This allows us to deduce new coeffi

A. Bonanno, J. Polonyi, D. Zappalá

The problem of two coupled scalar fields, one with mass much lighter than the other is analysed by means of Wilson&#39;s renormalization group approach. Coupled equations for the potential and the wave function renormalization are obtained by means of the gradient expansion. The Appelquist-Carazzone theorem is checked at energies comparable with the light ma

Saumen Datta, Sourendu Gupta, V. Ravindran

In hard interactions between external particles incident on a heat-bath, we show that large logarithms are generated when a radiated or absorbed gauge boson is collinear with the initial fermion momentum. These logarithms can be absorbed into process independent splitting/absorption probabilities. Unlike the zero-temperature case, however, they depend explic

Alberto Giovannini, Sergio Lupia, Roberto Ugoccioni

We show, via a simple parametrization of the multiplicity distribution of charged particles in e(+)e(-) annihilation at the Z0 peak in terms of the weighted superposition of two negative binomial distributions, that both the shoulder structure in the intermediate multiplicity range and the oscillation in sign of the ratio of factorial cumulants over factoria

Tom Blum, Carleton DeTar, Steven Gottlieb, Urs M. Heller

We study the effect of modifying the coupling of Kogut-Susskind quarks to the gauge field by replacing the link matrix in the quark action by a &#34;fat link&#34;, or sum of link plus three-link paths. Flavor symmetry breaking, determined by the mass difference between the Goldstone and non-Goldstone local pions, is reduced by approximately a factor of two b

T. Nakada

Experimental prospects for observing CP violation in B-meson decays are reviewed. Comparisons are made for various options: experiments at $e^+ e^-$ B-Meson Factories, HERA and the TEVATRON will produce results in near future. They will have a good chance to discover CP violation in B-meson decays. On a longer time scale, experiments at the LHC will aim at a

Siegfried Bethke

Measurements which probe the energy dependence of $α_s$, the coupling strength of the strong interaction, are reviewed. Jet counting in $e^+ e^-$ annihilation, combining results obtained in the centre of mass energy range from 22 to 133 GeV, provides direct evidence for an asymptotically free coupling, without the need to determine explicit values of $α_s$.

M. Sawaguchi, C. -B. Kim

The canonical formalism of three dimensional gravity coupled with the Dirac field is considered. We introduce complex variables to simplify the Dirac brackets of canonical variables and examine the canonical structure of the theory. We discuss the reality conditions which guarantee the equivalence between the complex and real theory.

Steven Duplij

Various semigroups of noninvertible supermatrices of the special (antitriangle) shape having nilpotent Berezinian which appear in supersymmetric theories are defined and investigated. A subset of them continuously represents left and right zero semigroups and rectangular bands. The ideal properties of higher order rectangular band analogs and the ``wreath&#3

M. Jaime, H. T. Hardner, M. B. Salamon, M. Rubinstein

The Hall coefficient of Gd-doped La_{2/3}Ca_{1/3}MnO_3 exhibits Arrhenius behavior over a temperature range from 2T_c to 4T_c, with an activation energy very close to 2/3 that of the electrical conductivity. Although both the doping level and thermoelectric coefficient indicate hole-like conduction, the Hall coefficient is electron-like. This unusual result

E. Miranda, V. Dobrosavljevic, G. Kotliar

We demonstrate that a model of disordered Anderson lattices can account for many non-Fermi liquid features observed in a number of Kondo alloys. Due to the exponential nature of the Kondo temperature scale, even moderate disorder leads to a rather broad distribution of Kondo temperatures, inducing strong effective disorder seen by the conduction electrons. S

L. Frachebourg, P. L. Krapivsky, S. Redner

We investigate the age distribution function P(tau,t) in prototypical one-dimensional coarsening processes. Here P(tau,t) is the probability density that in a time interval (0,t) a given site was last crossed by an interface in the coarsening process at time tau. We determine P(tau,t) analytically for two cases, the (deterministic) two-velocity ballistic ann

K. E. Bassler, D. A. Browne

We study a three species monomer-monomer catalytic surface reaction model with a reactive steady state bordered by three equivalent unreactive phases where the surface is saturated with one species. The transition from the reactive to a saturated phase shows directed percolation critical behavior. Each pair of these reactive-saturated phase boundaries join a

Yang Zhao, David W. Brown, Katja Lindenberg

In this paper we apply variational energy band theory to a form of the Holstein Hamiltonian in which the influence of lattice vibrations (optical phonons) on both local site energies (local coupling) and transfers of electronic excitations between neighboring sites (nonlocal coupling) is taken into account. A flexible spanning set of orthonormal eigenfunctio

Pierre Gaspard, Sudhir R. Jain

We present a treatment of many-body Fermionic systems that facilitates an expression of the well-known quantities in a series expansion of the Planck&#39;s constant. The ensuing semiclassical result contains to a leading order of the response function the classical time correlation function of the observable followed by the Weyl-Wigner series, on top of thes

B. Kyung, S. I. Mukhin, V. N. Kostur, R. A. Ferrell

We examine the effects of electron-phonon interaction on the dynamics of the charge carriers doped in two-dimensional (2D) Heisenberg antiferromagnet. The $t$-$J$ model Hamiltonian with a Fröhlich term which couples the holes to a dispersionless (optical) phonon mode is considered for low doping concentration. The evolution of the spectral density function,

Pierre Deltour, Jean-Louis Barrat

We present a numerical study of a two dimensional granular medium consisting of hard inelastic disks. The evolution of the medium throughout a cooling process is monitored. Two different types of instabilities (shearing and clustering instability) are found to develop in the system. The development of these instabilities is shown to be in qualitative and qua

P. Charlat, H. Courtois, Ph. Gandit, D. Mailly

We review transport measurements in a normal metal (N) in contact with one or two superconducting (S) islands. From the experiment, we distinguish the Josephson coupling, the mesoscopic fluctuations and the proximity effect. In a loop-shaped N conductor, we observe large h/2e-periodic magnetoresistance oscillations that decay with temperature T with a 1/T po

Peter Olsson

The fully frustrated XY model with Villain interaction on a square lattice is studied by means of Monte Carlo simulations. On the basis of the universal jump condition it is argued that there are two distinct transitions in the model, corresponding to the loss of XY order and Z_2 order, respectively. The Kosterlitz-Thouless (KT) transition is analyzed by fin

Ross H. McKenzie, David Scarratt

An exactly soluble one-dimensional model of electrons interacting with order parameter fluctations associated with short-range order is considered. The energy and momentum dependence of the electronic self energy and spectral function are calculated and found to exhibit non-Fermi-liquid features similar to that seen for the two-dimensional Hubbard model: a p

Sauro Succi

The lattice Boltzmann equation (LBE) is a microscopically-inspired method designed to solve macroscopic fluid dynamics problems. As a such, it lives at the interface between the microscopic (molecular) and macroscopic (continuum) worlds, hopefully capturing the best of the two. In this paper we shall discuss whether or not, after almost a decade since its in

Sudhir R. Jain, Daniel Alonso

We present a theory where the statistical mechanics for dilute ideal gases can be derived from random matrix approach. We show the connection of this approach with Srednicki approach which connects Berry conjecture with statistical mechanics. We further establish a link between Berry conjecture and random matrix theory, thus providing a unified edifice for q

Per Dahlqvist

We present numerical evidence that the dynamical zeta function and the Fredholm determinant of intermittent maps with a neutral fix point have branch point singularities at z=1 We consider the power series expansion of zeta function and the Fredholm determinant around z=0 with the fix point pruned. This power series is computed up to order 20, requiring 10^5

Craig J. Hogan

The predictions of Standard Big Bang Nucleosynthesis are summarized and compared with observations of abundances of helium in HII regions, deuterium in quasar absorbers, deuterium and helium-3 in the Galaxy, and lithium in metal-poor stars. It is concluded that the prospects are good for a precise test of the theory.

J. Wm. Parker, J. K. Hill, R. C. Bohlin, R. W. O'Connell

We present an analysis of far-ultraviolet (FUV: 130-180 nm) and optical (U, B, and V) data of the stellar and nebular content of the OB associations LH 9, 10, and 13 in the Large Magellanic Cloud region N 11. The FUV images from The Ultraviolet Imaging Telescope strongly select the hot O and B stars; over 1900 stars were detected in the FUV to a limiting mag

Y. K. Ng, M. Schultheis

A catalogue is presented with variable (RR Lyrae, semiregular and Mira) stars located inside field #3 of the Palomar-Groningen Survey, at the outer edge of the Sagittarius dwarf galaxy. One of the semiregular variables is a carbon star, comparable with those found by Azzopardi et al. (1991). Serendipity provides the suggestion, that their carbon stars might

Marc Kamionkowski, Arthur Kosowsky, Albert Stebbins

A formalism for describing an all-sky map of the polarization of the cosmic microwave background is presented. The polarization pattern on the sky can be decomposed into two geometrically distinct components. One of these components is not coupled to density inhomogeneities. A non-zero amplitude for this component of polarization can only be caused by tensor

Andrzej M. Soltan, Guenther Hasinger, Roland Egger, Steve Snowden

The intensity of the soft X-Ray background is correlated with the distribution of galaxies. To demonstrate this, magnitude limited galaxy samples extracted from bright galaxy catalogues and the Lick counts are utilized. Significant correlations are detected for all magnitude ranges, i.e. 10<m<18.6. The local X-ray volume emissivity between 0.5 and 2.0 keV co

M. Orito, T. Kajino, R N. Boyd, G J. Mathews

We discuss effects of fluctuation geometry on primordial nucleosynthesis. For the first time we consider condensed cylinder and cylindrical-shell fluctuation geometries in addition to condensed spheres and spherical shells. We find that a cylindrical shell geometry allows for an appreciably higher baryonic contribution to be the closure density ($Ω_b h_{50}^

S. T. Staggs, N. C. Jarosik, S. S. Meyer, D. T. Wilkinson

A balloon-borne experiment has measured the absolute temperature of the cosmic microwave background radiation (CMBR) at 10.7 GHz to be Tcmbr = 2.730 +- .014 K. The error is the quadratic sum of several systematic errors, with statistical error of less than 0.1 mK. The instrument comprises a cooled corrugated horn antenna coupled to a total-power radiometer.

Mohamed Laradji, Soeren Toxvaerd, Ole G. Mouritsen

Using large-scale molecular dynamics simulations of a two-component Lennard-Jones model in three dimensions, we show that the late-time dynamics of spinodal decomposition in concentrated binary fluids reaches a viscous scaling regime with a growth exponent $n=1$, in agreement with experiments and a theoretical analysis for viscous growth.

Claudio Corianò, Alan R. White, Mark Wüsthoff

We show that a scale invariant approximation to the next-to-leading order BFKL kernel, constructed via transverse momentum diagrams, has a simple conformally invariant representation in impact parameter space i.e. K(r1,r2,r1&#39;,r2&#39;) = g^4 N^2 ln^4[(|r1-r1&#39;||r2-r2&#39;|)/(|r1-r2&#39;||r2-r1&#39;|)] That a conformally invariant representation exists

M. Alishahiha

We obtain the closed form of the Picard-Fuchs equations for $N=2$ supersymmetric Yang-Mills theories with classical Lie gauge groups. For a gauge group of rank $r$, there are $r-1$ regular and an exceptional differential equations. We describe the series solutions of the Picard-Fuchs equations in the semi-classical regime.

M. V. Feigel&#39;man, M. A. Skvortsov

Low-temperature dissipation due to vortex motion in strongly anisotropic type-II superconductors with a moderate disorder ($Δ^2/E_F \ll \hbar/τ\ll Δ$) is shown to be determined by the Zener-type transitions between the localized electronic states in the vortex core. Statistics of these levels is described by the random matrix ensemble of the class C defined

J. L. Jacquot

We regularize in a continuous manner the path integral of QED by construction of a non-local version of its action by means of a regularized form of Dirac's $\delta$ functions. Since the action and the measure are both invariant under the gauge group, this regularization scheme is intrinsically non-perturbative. Despite the fact that the non-local action con

Andrei L. Kataev

The brief overview of the definite determinations of the QCD coupling constant $α_s$ from the characteristics of deep-inelastic scattering processes is given.

Florian Nill

We give a review and some new relations on the structure of the monodromy algebra (also called loop algebra) associated with a quasitriangular Hopf algebra H. It is shown that as an algebra it coincides with the so-called braided group constructed by S. Majid on the dual of H. Gauge transformations act on monodromy algebras via the coadjoint action. Applying

E. N. Argyres, C. G. Papadopoulos, M. Bruinsma, R. Kleiss

We discuss the structure of scalar field theories having the property that all on-shell S-matrix elements vanish in tree approximation. It is shown that there exists a large class of such theories, with derivative couplings, which are all locally related to a free theory by a nonlinear transformation. It is also shown that a field-dependent wave-function ren

Marc Potters, Rama Cont, Jean-Philippe Bouchaud

We show, by studying in detail the market prices of options on liquid markets, that the market has empirically corrected the simple, but inadequate Black-Scholes formula to account for two important statistical features of asset fluctuations: `fat tails&#39; and correlations in the scale of fluctuations. These aspects, although not included in the pricing mo

F. Bernardeau, L. van Waerbeke, Y. Mellier

The possibility of detecting weak lensing effects from deep wide field imaging surveys has open new means of probing the large-scale structures of the Universe and measuring cosmological parameters. In this paper we present a systematic study of the expected dependence of the low order moments of the filtered gravitational local convergence with the power sp

Stephen Eales, Mike Edmunds

This is the second of two papers describing a model of galactic evolution in the submillimetre waveband. The model incorporates a self-consistent treatment of the evolution of dust and stars, is normalized to the submillimetre properties of galaxies in the local universe, and can be used to make predictions for both disk and elliptical galaxies and for `clos

Kikuo Harigaya

The component of photoexcited states with large spatial extent is investigated for poly(para-phenylenevinylene) using the intermediate exciton theory. We find a peak due to long-range excitons at the higher-energy side of the lowest main feature of optical spectra. The fact that the onset of long-range excitons is located near the energy gap is related to th

Y. Arakane, H. Itoyama, H. Kunitomo, A. Tokura

Nonvanishing tadpoles and possible infinities associated in the multiparticle amplitudes are discussed with regard to the disk and $RP^{2}$ diagrams of the Type I&#39; compactification. We find that the infinity cancellation of $SO(32)$ type $I$ theory extends to this case as well despite the presence of tadpoles localized in the D-brane world-volume and the

T. W. Allen, C. J. Burden

The homogeneous Bethe-Salpeter equation is solved in the quenched ladder approximation for the vector positronium states of 4-component quantum electrodynamics in 2 space and 1 time dimensions. Fermion propagator input is from a Rainbow approximation Dyson-Schwinger solution, with a broad range of fermion masses considered. This work is an extension of earli

A. V. Radyushkin

In this talk I report on recent progress in a few areas closely related to the virtual Compton scattering studies. In particular, I discuss the quark-hadron duality estimate of the $γ^* p \to Δ^+$ transition, QCD sum rule calculation of the $γγ^* \to π^0$ form factor, and application of perturbative QCD to deeply virtual Compton scattering at small $t$.

Yasumasa Hasegawa

We show that the density of states in an anisotropic superconductor with intersecting line nodes in the gap function is proportional to $E log (αΔ_0 /E)$ for $|E| << Δ_0$, where $Δ_0$ is the maximum value of the gap function and $α$ is constant, while it is proportional to $E$ if the line nodes do not intersect. As a result, a logarithmic correction appears

Asher Peres

A quantum codeword is a redundant representation of a logical qubit by means of several physical qubits. It is constructed in such a way that if one of the physical qubits is perturbed, for example if it gets entangled with an unknown environment, there still is enough information encoded in the other physical qubits to restore the logical qubit, and disenta

Giuseppe Vitiello

I discuss the role of quantum dynamics in brain and living matter physics. The paper is presented in the form of a letter to Patricia S. Churchland.

W-S. Chung

In this paper the coherent states and q-symmetric states for $gl_q(n)$-covariant multimode oscillator system are investigated.

H. Beer, C. Coceva, R. Hofinger, P. Mohr

Thermal neutron capture cross sections for $^{34}$S(n,$γ$)$^{35}$S and $^{36}$S(n,$γ$)$^{37}$S have been measured and spectroscopic factors of the final states have been extracted. The calculated direct-capture cross sections reproduce the experimental data.

Linda E. Green

Let $\F$ be a compact surface and let $I$ be the unit interval. This paper gives a standard form for all 2-sided incompressible surfaces in the 3-manifold $\F \times I$. Since $\F \times I$ is a handlebody when $\F$ has boundary, this standard form applies to incompressible surfaces in a handlebody.

George Chapline

The pattern of duality symmetries acting on the states of compactified superstring models reinforces an earlier suggestion that the Monster sporadic group is a hidden symmetry for superstring models. This in turn points to a supersymmetric theory of self-dual and anti-self-dual K3 manifolds joined by Dirac strings and evolving in a 13 dimensional spacetime a

Nathan Seiberg

We start a systematic analysis of supersymmetric field theories in six dimensions. We find necessary conditions for the existence of non-trivial interacting fixed points. String theory provides us with examples of such theories. We conjecture that there are many other examples.

B. M. McCoy

Metaphysics is the science of being and asks the question ``What really exists?&#39;&#39; The answer to this question has been sought for by mankind since the beginning of recorded time. In the past 2500 years there have been many answers to this question and these answers dominate our view of how physics is done. Examples of questions which were originally

Edward Witten

We interpret certain strong coupling singularities of the $E_8\times E_8$ heterotic string on K3 in terms of exotic six-dimensional theories in which $E_8$ is a gauge symmetry. These theories are closely related to theories obtained at small instanton singularities, which have $E_8$ as a global symmetry.

A. de Souza Dutra

We present a strong-weak coupling duality for quantum mechanical potentials. Similarly to what happens in quantum field theory, it relates two problems with inverse couplings, leading to a mapping of the strong coupling regime into the weak one, giving information from the nonperturbative region of the parameters space. It can be used to solve exactly power-

C. Adam

Within the framework of Euclidean path integral and mass perturbation theory we compute the Wilson loop of widely separated external charges for the massive Schwinger model. From this result we show for arbitrary order mass perturbation theory that integer external charges are completely screened, whereas for noninteger charges a constant long-range force re

C. Adam

By a closer inspection of the massive Schwinger model within mass perturbation theory we find that, in addition to the $n$-boson bound states, a further type of hybrid bound states has to be included into the model. Further we explicitly compute the decay widths of the three-boson bound state and of the lightest hybrid bound state.

Giovanni Felder

In this paper, based on the author&#39;s lectures at the 1995 les Houches Summer school, explicit expressions for the Friedan--Shenker connection on the vector bundle of WZW conformal blocks on the moduli space of curves with tangent vectors at $n$ marked points are given. The covariant derivatives are expressed in terms of ``dynamical $r$-matrices&#39;&#39;

Gautam Sengupta

A geometrical approach in the non-symmetric connection framework is employed to examine the issue of higher order $α&#39;$ corrections to D=10 type IIB superstring backgrounds with a covariantly constant null Killing isometry and non-zero Ramond-Ramond field content. These describe generalized supersymmetric string waves and were obtained recently by us thro

Elizabeth Jenkins

Predictions of unknown heavy baryon masses based on an expansion in $1/m_Q$, $1/N_c$ and $SU(3)$ breaking are updated to take into account a recent measurement of the $Σ_c^*$ mass. Values are given for the two remaining unknown charm baryon masses $Ξ_c^\prime$ and $Ω_c^*$ and the seven unknown bottom baryon masses $Ξ_b, Σ_b, Ξ_b^\prime, Ω_b, Σ_b^*, Ξ_b^*$ an

L. E. Gordon

The utility of prompt photon plus associated jet production for constraining the size and shape of the polarized gluon density of the proton $ΔG$ is examined at $\sqrt{S}=40$ GeV, appropriate for the proposed HERA-$\vec{N}$ polarized $\vec{p}\vec{p}$ collider experiment. The calculation is performed at next-to-leading order (O($αα_s^2$)) in QCD. The reliabil

G. Couture, H. König

We present an overview of the loop corrections to the mass difference $Δm_{B_d^0}/ m_{B_d^0}$ within the minimal supersymmetric standard model. We include the complete mixing matrices of the charginos and neutralinos as well as of the scalar partners of the left and right handed third generation quarks. We show that the SUSY contribution to the mass differen

Brandon Carter, Patrick Peter, Alejandro Gangui

Earlier attempts to calculate the nonlinear dynamical evolution of Witten type superconducting vacuum vortex defects relied on the use of approximate conducting string models that were too simple to take proper account of the effect of current saturation. This effect is however allowed for adequately in a newly developed class of rather more complicated, tho