November 1995 arXiv papers — page 5

Dmitry A. Ryndyk

We obtain self-consistent macroscopic equations describing interlayer Josephson effect and intralayer disequilibrium in one-dimensional array of Josephson coupled layers. We show that ``nonequilibrium coupling'' can lead to effective spatial and time synchronization and formation of coherent dynamic resistive state (collective Josephson effect) in Nb

Henry P. Stapp, Takahiro Kawai

Accurate calculations of macroscopic and mesoscopic properties in quantum electrodynamics require careful treatment of infrared divergences: standard treatments introduce spurious large-distances effects. A method for computing these properties was developed in a companion paper. That method depends upon a result obtained here about the nature of the singula

Charles H. Bennett, Herbert J. Bernstein, Sandu Popescu, Benjamin Schumacher

If two separated observers are supplied with entanglement, in the form of $n$ pairs of particles in identical partly-entangled pure states, one member of each pair being given to each observer; they can, by local actions of each observer, concentrate this entanglement into a smaller number of maximally-entangled pairs of particles, for example Einstein-Podol

Henry P. Stapp

Contemporary quantum mechanical description of nature involves two processes. The first is a dynamical process governed by the equations of local quantum field theory. This process is local and deterministic, but it generates a structure that is not compatible with observed reality. A second process is therefore invoked. This second process somehow analyzes

L. S. F. Olavo

We continue in this paper our program of rederiving all quantum mechanical formalism from the classical one. We now turn our attention to the derivation of the second quantized equations, both for integral and half-integral spins. We then show that all the quantum results may be derived using our approach and also show the interpretation suggested by this de

Pavlos Protopapas, Abraham Klein, Niels R. Walet

In a previous paper a semi-microscopic core-particle coupling method that includes the conventional strong coupling core-particle model as a limiting case, was applied to spectra and electromagnetic properties of several well-deformed odd nuclei. This work, coupled a large single-particle space to the ground state bands of the neighboring even cores. In this

Miroljub Jevtić, Xavier Massaneda, Pascal J. Thomas

Let $B_α^{p}$ be the space of $f$ holomorphic in the unit ball of $\Bbb C^n$ such that $(1-|z|^2)^αf(z) \in L^p$, where $0<p\leq\infty$, $α\geq -1/p$ (weighted Bergman space). In this paper we study the interpolating sequences for various $B_α^{p}$. The limiting cases $α=-1/p$ and $p=\infty$ are respectively the Hardy spaces $H^p$ and $A^{-α}$, the holomorph

David W. Catlin, John P. D&#39;Angelo

We consider positivity conditions both for real-valued functions of several complex variables and for Hermitian forms. We prove a stabilization theorem relating these two notions, and give some applications to proper mappings between balls in different dimensions. The technique of proof relies on the simple expression for the Bergman kernel function for the

Andrew K. Waldron

We give an explicit demonstration, using the rigorous Feynman rules developed in~$\0^{1}$, that the regularized trace $\tr γ_5 e^{-β\Dslash^2}$ for the gravitational chiral anomaly expressed as an appropriate quantum mechanical path integral is $β$-independent up to two-loop level. Identities and diagrammatic notations are developed to facilitate rapid evalu

J. -G. Demers, C. Kiefer

We discuss in detail the semiclassical approximation for the CGHS model of two-dimensional dilatonic black holes. This is achieved by a formal expansion of the full Wheeler-DeWitt equation and the momentum constraint in powers of the gravitational constant. In highest order, the classical CGHS solution is recovered. The next order yields a functional Schrödi

Dmitri M. Gitman

A class class of transformations in a super phase space (we call them D-transformations) is described, which play in theories with second-class constraints the role of ordinary canonical transformations in theories without constraints.

Marc Henneaux

Let $B_{μν}^a$ ($a=1,...,N$) be a system of $N$ free two-form gauge fields, with field strengths $H_{μνρ}^a = 3 \partial _{[μ}B_{νρ]}^a$ and free action $S_0$ equal to $(-1/12)\int d^nx\ g_{ab}H_{μνρ}^aH^{bμνρ}$ ($n\geq 4$). It is shown that in $n>4$ dimensions, the only consistent local interactions that can be added to the free action are given by function

Mikhail S. Plyushchay

(2+1)-dimensional relativistic fractional spin particles are considered within the framework of the group-theoretical approach to anyons starting from the level of classical mechanics and concluding by the construction of the minimal set of linear differential field equations.

Lina Paria, M. G. Mustafa, Afsar Abbas

We show that a heavy glueball (much heavier than that studied by others which is in the range of 1-2 GeV) is generated in a pure gluon plasma when color-singletness condition is imposed on the partition function at finite temperature. This confirms Abbas&#39;s recent prediction (hep-ph/9504430) of the existence of a heavy glueball within the framework of the

N. N. Nikolaev, G. Piller, B. G. Zakharov

We describe a light-cone wave function formulation for hadroproduction of heavy-flavors at high energies. At moderate values of $x_F$ heavy-flavor production can be viewed as a diffractive excitation of heavy quark-antiquark Fock states, present in the interacting gluon from the projectile. The approach developed here is well suited to address coherence effe

S. V. Goloskokov

Transverse single spin asymmetry in polarized diffractive $Q \bar Q$ production is calculated. It is shown that this asymmetry depends strongly on the spin structure of the pomeron coupling, which permits one to study the pomeron couplings properties in future polarized experiments.

H. Fujisaki, K. Kumekawa, M. Yamaguchi, M. Yoshimura

Thermal history after inflation is studied in a chaotic inflation model with supersymmetric couplings of the inflaton to matter fields. Time evolution equation is solved in a formalism that incorporates both the back reaction of particle production and the cosmological expansion. The effect of the parametric resonance gives rise to a rapid initial phase of t

J. Kwiecinski

The perturbative QCD predictions for the small $x$ behaviour of the nucleon structure functions $F_{2,L}(x,Q^2)$ and $g_1(x,Q^2)$ are summarized. The importance of the double logarithmic terms for the small $x$ behaviour of the spin structure function $g_1(x,Q^2)$ is emphasised. These terms correspond to the contributions containing the leading powers of $α_

T. Hotta, T. Izubuchi, J. Nishimura

We study four--dimensional simplicial gravity through numerical simulation with special attention to the existence of singular vertices, in the strong coupling phase, that are shared by abnormally large numbers of four--simplices. The second order phase transition from the strong coupling phase into the weak coupling phase could be understood as the disappea

J. Salas, A. D. Sokal

We study the dynamic critical behavior of a Swendsen-Wang-type algorithm for the Ashkin--Teller model. We find that the Li--Sokal bound on the autocorrelation time ($τ_{{\rm int},{\cal E}} \ge {\rm const} \times C_H$) holds along the self-dual curve of the symmetric Ashkin--Teller model, and is almost but not quite sharp. The ratio $τ_{{\rm int},{\cal E}} /

Thomas Thiemann

For various theories, in particular gauge field theories, the algebraic form of the Hamiltonian simplifies considerably if one writes it in terms of certain complex variables. Also general relativity when written in the new canonical variables introduced by Ashtekar belongs to that category, the Hamiltonian being replaced by the so-called scalar (or Wheeler-

G. S. Hall, M. J. Reboucas, J. Santos, A. F. F. Teixeira

A new approach to the algebraic classification of second order symmetric tensors in 5-dimensional space-times is presented. The possible Segre types for a symmetric two-tensor are found. A set of canonical forms for each Segre type is obtained. A theorem which collects together some basic results on the algebraic structure of the Ricci tensor in 5-dimensiona

S. N. Coppersmith, C. -h. Liu, S. Majumdar, O. Narayan

We study theoretically the complex network of forces that is responsible for the static structure and properties of granular materials. We present detailed calculations for a model in which the fluctuations in the force distribution arise because of variations in the contact angles and the constraints imposed by the force balance on each bead of the pile. We

E. Brézin, S. Hikami, A. Zee

We consider random hermitian matrices made of complex blocks. The symmetries of these matrices force them to have pairs of opposite real eigenvalues, so that the average density of eigenvalues must vanish at the origin. These densities are studied for finite $N\times N$ matrices in the Gaussian ensemble. In the large $N$ limit the density of eigenvalues is g

I. Zapata, F. Sols

Supercurrent flow is studied in a structure that in the Ginzburg-Landau regime can be described in terms of an effective double barrier potential. In the limit of strongly reflecting barriers, the passage of Cooper pairs through such a structure may be viewed as a realization of resonant tunneling with a rigid wave function. For interbarrier distances smalle

J. Kondev, C. L. Henley

The symmetries of critical ground states of two-dimensional lattice models are investigated. We show how mapping a critical ground state to a model of a rough interface can be used to identify the chiral symmetry algebra of the conformal field theory that describes its scaling limit. This is demonstrated in the case of the six-vertex model, the three-colorin

Keiko Miyahata, Satoru Ikeuchi

We investigate the physical properties of a two-component virialized protogalaxy comprising a hot gas and cold clouds which are in pressure equilibrium under the assumptions that the protogalaxy is both spherical and homogeneous. Two conditions which we adopt are that the protogalaxy is in virial equilibrium and that the cooling time is less than the dynamic

Gary Mamon, Vincent Banchet, Catherine Boisson, Veronique Cayatte

We review the various steps for the extraction of extended sources, principally galaxies, from the DENIS images. The capabilities of DENIS are studied with simulated images. A few real DENIS J and K_s-band images are presented for very bright galaxies and one nearby rich galaxy cluster.

Eduardo Telles, Roberto Terlevich

We present high spatial resolution CCD surface photometry study in the optical V, R and I filters of 15 HII galaxies from the Nordic Optical Telescope and the Jacobus Kapteyn Telescope at Canary Islands. The colours of the starburst continuum and of the underlying galaxy are measured. The distribution of colours of the underlying galaxy in HII galaxies is si

R. Srianand

The clustering properties of Ly ${\alpha}$ lines are analysed using an intermediate resolution ($\sim 1\AA$) spectra of 67 QSOs compiled from the literature. The pair velocity correlation function indicates a weak excess in the velocity intervals up to ${\rm \Delta v\;=\;600\; km\;s^{-1}}$. The z-integrated probability distribution of interline spacings also

Ravi K. Sheth

With appropriate modifications, the Hoffman--Ribak algorithm that constructs constrained realizations of Gaussian random fields having the correct ensemble properties can also be used to construct constrained realizations of those non-Gaussian random fields that are obtained by transformations of an underlying Gaussian field. For example, constrained realiza

Kevin Krisciunas, Theodore Simon, Richard A. Crowe, Mavourneen Roberts

71 Tau was discovered to be a $δ$ Scuti star by Horan (1979, AJ 84, 1770). To our knowledge no other photometry of this star has been published. 71 Tau is the second brightest X-ray source in the Hyades and has been shown to be variable by as much as 30 \% at ultraviolet wavelengths near 1700 to 2000 Å. We find that the best two-frequency fit to the new phot

Pavel Katsylo

We investigate the 2-dimensional jacobian conjecture via Klein&#39;s program.

Ravi Kuchimanchi

There is a natural solution to the strong CP problem in the Minimal Supersymmetric Standard Model if it arises from a parity symmetric theory which is spontaneously broken to MSSM at Planck, GUT or intermediate scales. The strong CP phase is zero at the tree level and is not induced to two loops. The SUSY phase problems are also solved. The universal soft SU

Charles H. Bennett, Gilles Brassard, Sandu Popescu, Benjamin Schumacher

Two separated observers, by applying local operations to a supply of not-too-impure entangled states ({\em e.g.} singlets shared through a noisy channel), can prepare a smaller number of entangled pairs of arbitrarily high purity ({\em e.g.} near-perfect singlets). These can then be used to faithfully teleport unknown quantum states from one observer to the

C. Ordonez, L. Ray, U. van Kolck

Chiral symmetry is consistently implemented in the two-nucleon problem at low-energy through the general effective chiral lagrangian. The potential is obtained up to a certain order in chiral perturbation theory both in momentum and coordinate space. Results of a fit to scattering phase shifts and bound state data are presented, where satisfactory agreement

Luis A. Anchordoqui, Diego F. Torres, Héctor Vucetich

The deviation of primordial Helium production due to a variation on the difference between the rest masses of the nucleons is presented. It is found an upper bound $δ(M_{_n} - M_{_p}) \alt 0.129$ MeV, between the present and nucleosynthesis epochs. This bound is used to analyze Wesson&#39;s theory of gravitation; as a result, it is ruled out by observation.

Sabino Matarrese, David Terranova

The non-linear dynamics of irrotational dust in General Relativity is studied in synchronous and comoving coordinates. All the equations are written in terms of the metric tensor of spatial sections orthogonal to the flow, which allows an unambiguous expansion in powers of $1/c^2$. To lowest order, the Newtonian approximation in Lagrangian form is derived. A

Glenn A. Ladinsky

The study of two spin asymmetries in hadron-hadron collisions probes the details of fundamental particle interactions in ways infeasible to machines with unpolarized collisions. Within reach is how the proton spin is distributed among its constituents through $ΔG$ and $Δ\bar{q}$. Measuring couplings, furthering our understanding jet structure and uncovering

K. J. Barnes, O. J. Senior, N. D. Virgo

We construct quark mixing matrices within a group theoretic framework which is easily applicable to any number of generations. Familiar cases are retrieved and related, and it is hoped that our viewpoint may have advantages both phenomenologically and for constructing underlying mass matrix schemes.

J. Donin, D. Gurevich, V. Rubtsov

When a quantum hyperboloid is realized, as a three - parameter algebra $\ahqc$, in the usual manner, the following problem arises: what is a ``representation theory'' of this algebra? We construct the series of all spin representations of $\ahqc$, and we discuss a braided version of the orbit method, i.e. a correspondence between orbits in $\gggg^*$ and $\gg

M. D&#39;Elia, F. Farchioni, A. Papa

We study the renormalization group evolution up to the fixed point of the lattice topological susceptibility in the 2-d O(3) non-linear sigma-model. We start with a discretization of the continuum topological charge by a local charge density, polynomial in the lattice fields. Among the different choices we propose also a Symanzik--improved lattice topologica

Alexander Gorsky, Konstantin Selivanov

We discuss the threshold tree amplitudes in diverse nonintegrable quantum field theories in the framework of integrability. The amplitudes are related to some Baker functions defined on the auxiliary spectral curves and the nullification phenomena are shown to allow a topological interpretation.

Giuseppe Santoro, Nicola Manini, Alberto Parola, Erio Tosatti

The $1D$ phase diagram of a model for correlated hopping of electrons in a lattice of Berry phase molecules is presented. Electrons hop in presence of an extra orbital degree of freedom at each site. This is mimicked as a spin-1 variable whose allowed states depend on the electron occupancy so as to take into account the orbital degeneracies of different mol

J. P. Dewitz, W. Huebner, K. H. Bennemann

Using classical electrodynamics we determine the higher harmonic radiation by a nonspherical metal cluster in form of a matrix formalism. Extending the theory for the source of the higher harmonic radiation for spherical metal clusters as introduced by Östling et al. [Z. Phys. D {\bf 28}, 169 (1993)] we calculate the sources for nonspherical particles. Emplo

Valerii V. Dolotin

In this paper we propose a conseptual framework for the observed properties of discriminants of polylinear forms. The connection with classical problems of linear algebra is shown. A new class of algebraic varieties (hypergrassmanians) is introduced, the particular case of which are grassman manifolds. An algorithm is given for computing the discriminants of

Ch. Gruber, N. Macris, A. Messager, D. Ueltschi

The Falicov-Kimball model is a lattice model of itinerant spinless fermions (&#34;electrons&#34;) interacting by an on-site potential with classical particles (&#34;ions&#34;). We continue the investigations of the crystalline ground states that appear for various filling of electrons and ions, for large coupling. We investigate the model for square as well

L. Anton

The dynamics of the avalanche width in the evolution model is described using a random walk picture. In this approach the critical exponents for avalanche distribution, $τ$, and avalanche average time, $γ$, are found to be the same as in the previous mean field approximation but SOC appear at $λ_{critical}=2/3$, which is very close to numerical value. A cont

F. Cardarelli, I. L. Grach, I. M. Narodetskii, G. Salme&#39;

The elastic and transition electromagnetic form factors of mesons are investigated within a light-front constituent quark model. The general formulae for the space-like matrix elements of the one-body component of the electromagnetic current, including both Dirac and Pauli form factors of the constituent quarks, are presented. Our results for the pion charge

L. -W. Chen, A. C. Fabian, K. C. Gendreau

The X-ray background (XRB) from 0.1 to 7 keV has been studied using high spectral and spatial resolution data from the ASCA SIS and ROSAT PSPC. Analysing both the diffuse background radiation and resolved sources, we have carried out a series of joint spectral fits of the ASCA and ROSAT data. The spectrum of the XRB can be fit well by a single power-law from

A. Yu. Kitaev

We present a polynomial quantum algorithm for the Abelian stabilizer problem which includes both factoring and the discrete logarithm. Thus we extend famous Shor&#39;s results. Our method is based on a procedure for measuring an eigenvalue of a unitary operator. Another application of this procedure is a polynomial quantum Fourier transform algorithm for an

Hoi-Kwong Lo, H. F. Chau

We provide a complete proof of the security of quantum cryptography against any eavesdropping attack including coherent measurements even in the presence of noise. Polarization-based cryptographic schemes are shown to be equivalent to EPR-based schemes. We also show that the performance of a noisy channel approaches that of a noiseless one as the error rate

Roberto Casadio, Giovanni Venturi

An extended monopole detector at constant acceleration coupled to a massless scalar field is allowed to evolve quantum mechanically. It is found that while in the classical, followed by the point particle, limit the usual result Unruh effect is recovered, in the point particle (before the classical) limit the detector decouples from the scalar field and ther

Michael Simpson

A thought experiment considering conservation of energy and momentum for a pair of free bodies together with their internal energy is used to show the existence of states that have localised position while being eigenstates of energy and momentum. These states are applicable to all varieties of physical bodies, including planets and stars in free motion in t

Thomas A. Kaeding, H. Thomas Williams

A C-Language program which tabulates the isoscalar factors and Clebsch-Gordan coefficients for products of representations in SU(3) is presented. These are efficiently computed using recursion relations, and the results are presented in exact precision as square roots of rational numbers. Output is in LaTeX format.

K. Hagino, N. Takigawa, M. Abe

We calculate the electron screening effect in low energy nuclear fusion reactions by taking non-adiabaticity of the tunnleing process into account. In order to investigate deviations from the adiabatic limit, we use the dynamical norm method, which has recently been developed by the present authors. Using $d$+D reaction as an example, we show that the screen

Jan de Boer, Bas Peeters, Kostas Skenderis, Peter van Nieuwenhuizen

We give background material and some details of calculations for two recent papers [1,2] where we derived a path integral representation of the transition element for supersymmetric and nonsupersymmetric nonlinear sigma models in one dimension (quantum mechanics). Our approach starts from a Hamiltonian $H(\hat{x}, \hat{p}, \hatψ, \hatψ^\dagger)$ with a prior

Brian J. Hand, George Leibbrandt

We test the unified-gauge formalism by computing a Wilson loop in Yang-Mills theory to one-loop order. The unified-gauge formalism is characterized by the abritrary, but fixed, four-vector $N_μ$, which collectively represents the light-cone gauge $(N^2 = 0)$, the temporal gauge $(N^2 > 0)$, the pure axial gauge $(N^2 < 0)$ and the planar gauge $(N^2 < 0)$. A

Tobias Hurth

We present some generalizations of a recently proposed alternative approach to nonabelian gauge theories based on the causal Epstein-Glaser method in perturbative quantum field theory. Nonabelian gauge invariance is defined by a simple commutator relation in every order of perturbation theory separately using only the linear (abelian) BRS-transformations of

Carl M. Bender, Gerald V. Dunne

This paper shows that there is a correspondence between quasi-exactly solvable models in quantum mechanics and sets of orthogonal polynomials $\{ P_n\}$. The quantum-mechanical wave function is the generating function for the $P_n (E)$, which are polynomials in the energy $E$. The condition of quasi-exact solvability is reflected in the vanishing of the norm

H. Hamidian, S. Jaimungal, G. W. Semenoff, P. Suranyi

We argue that chiral symmetry breaking in three dimensional QCD can be identified with Néel order in 2-dimensional quantum antiferromagnets. When operators which drive the chiral transition are added to these theories, we postulate that the resulting quantum critical behavior is in the universality class of gauged Yukawa matrix models. As a consequence, the

S. J. Brodsky, D. G. Robertson

In principle, quantum chromodynamics provides a fundamental description of hadronic and nuclear structure and dynamics in terms of their elementary quark and gluon degrees of freedom. In practice, the direct application of QCD to reactions involving the structure of hadrons is complex because of the interplay of nonperturbative effects such as color confinem

A. Schaefer

We discuss the status of atomic physics in strong field. We focus on the problem of electron-positron lines observed in heavy-ion collisions and on QED effects, calculated in strong Coulomb fields, especially Delbrück-scattering. We discuss the similarities and differences between these effects and channeling respectively beamstrahlung. We investigated the p

C. D. Froggatt, H. B. Nielsen

Imposing the constraint that the Standard Model effective Higgs potential should have two degenerate minima ( vacua), one of which should be - order of magnitudewise - at the Planck scale, leads to the top mass being 173 +/- 5 GeV and the Higgs mass 135 +/- 9 GeV. This requirement of the degeneracy of different phases is a special case of what we call the mu

G. P. Korchemsky

I review a recent progress in understanding the Regge asymptotics in perturbative QCD including the behaviour of the structure functions of DIS at small Bjorken $x$.

M. Shmatikov

Possible existence of a molecular-type heavy-flavored strange pentaquark is considered. No narrow state of such a type is shown to exist.

M. E. Pospelov

CP-violating interaction of quarks and W-bosons with the scalar field background is studied in the Kobayashi-Maskawa with with Standard Model content of flavors and with additional heavy generation of fermions. The corresponding two-loop induced formfactors are calculated at zero temperature. The results are generalized at large momentum transfers to take in

Masaharu Tanabashi

Equivalence of the hidden local symmetry formulation with non-minimal interactions and the anti-symmetric tensor field method of $ρ$ and $a_1$ mesons in the chiral lagrangian is shown by using the auxiliary field method. Violation of the KSRF I relation, which becomes important in the application of chiral lagrangian to {\em non QCD-like} technicolor models

Roberto Casadio, Giovanni Venturi

An open system consisting of a scalar field bound to a Kerr black hole whose mass ($M$) and specific angular momentum ($a$) are slowly (adiabatically) perturbed is considered. The adiabatically induced phase and the conditions for the validity of the adiabatic approximation are obtained. The effect of closed cycles in parameter space ($a$, $M$ plane) on the

A. Griffin

The density functional theory originally developed by Hohenberg, Kohn and Sham provides a rigorous conceptual framework for dealing with inhomogeneous interacting Fermi systems. We extend this approach to deal with inhomogeneous interacting Bose-condensed systems, limiting this presentation to setting up the formalism to deal with ground state $(T=0)$ proper

A. Griffin, S. Stringari

We present arguments that the low density surface region of self-bounded superfluid $^4$He systems is an inhomogeneous dilute Bose gas, with almost all of the atoms occupying the same single-particle state at $T = 0$. Numerical evidence for this complete Bose-Einstein condensation was first given by the many-body variational calculations of $^4$He droplets b

J. M. Heisz, E. Zaremba

We have calculated the resistivity of a GaAs\slash AlGaAs heterojunction in the presence of both an in--plane magnetic field and a weak perpendicular component using a semiclassical Boltzmann transport theory. These calculations take into account fully the distortion of the Fermi contour which is induced by the parallel magnetic field. The scattering of elec

E. Dagotto, A. Nazarenko, A. Moreo, S. Haas

We briefly review a theory for the cuprates that has been recently proposed based on the movement and interaction of holes in antiferromagnetic (AF) backgrounds. A robust peak in the hole density of states (DOS) is crucial to produce a large critical temperature once a source of hole attraction is identified. The predictions of this scenario are compared wit

R. Goetter, K. Kroy, E. Frey, M. Baermann

Quasi-elastic light scattering (QELS) is applied to investigate the effect of the tropomyosin/troponin complex (Tm/Tn) on the stiffness of actin filaments. The importance of hydrodynamic screening in semidilute solutions is demonstrated. A new concentration dependent expression for the dynamic structure factor $g(\bm k,t)$ of semiflexible polymers in semidil

P. Lederer, Elihu Abrahams

We discuss the possible existence of a spin-gap phase in the low-doping regime of strongly-correlated two-dimensional electrons within the gauge field description of the t-J model. The spin-gap phase was recently shown by Ubbens and Lee to be destroyed by gauge field quantum fluctuations for a single-layer 2D system in the absence of disorder and for a full

S. Prestipino, G. Santoro, E. Tosatt

Preroughening of close-packed fcc(111) surfaces, found in rare gas solids, is an interesting, but poorly characterized phase transition. We introduce a restricted solid-on-solid model, named FCSOS, which describes it. Using mostly Monte Carlo, we study both statics, including critical behavior and scattering properties, and dynamics, including surface diffus

Jasmin Jijina, Fred C. Adams

In this paper, we study infall collapse solutions for star formation in the small radius limit where the particle orbits become nearly pressure-free. We generalize previous solutions to simultaneously include the effects of both radiation pressure and angular momentum. The effects of radiation pressure can be modeled using a modified potential; for represent

P. J. Armitage, M. Livio, J. E. Pringle

We explore the consequences of a magnetic dynamo origin for the viscosity in accretion discs, for the structure and evolution of discs in dwarf nova systems. We propose that the rapid cooling that sets in at the end of a dwarf nova eruption acts to inhibit the Balbus-Hawley instability, and thereby to quench dynamo action and so reduce disc viscosity. We dem

C. B. de Boisanger, F. P. Helmich, E. F. van Dishoeck

We present submillimeter observations of various molecular ions toward two dense clouds, NGC 2264 IRS1 and W 3 IRS5, in order to investigate their ionization fraction. Analysis of the line intensity ratios by the way of statistical equilibrium calculations allows determination of the physical parameters: n(H2)~(1-2)e6 cm-3 and T(kin)~50-100 K. Column densiti

J. Perez, J-M Alimi, J-J Aly, H. Scholl

We have performed a series of high resolution N-body experiments on a Connection Machine CM-5 in order to study the stability of collisionless self-gravitating spherical systems. We interpret our results in the framework of symplectic mechanics, which provides the definition of a new class of particular perturbations: The preserving perturbations, which are

Attilio Cucchieri, Tereza Mendes

We study the problem of critical slowing-down for gauge-fixing algorithms (Landau gauge) in $SU(2)$ lattice gauge theory on a $2$-dimensional lattice. We consider five such algorithms, and lattice sizes ranging from $8^{2}$ to $36^{2}$ (up to $64^2$ in the case of Fourier acceleration). We measure four different observables and we find that for each given al

John C. Baez, Martin Neuchl

We begin with a brief sketch of what is known and conjectured concerning braided monoidal 2-categories and their applications to 4d topological quantum field theories and 2-tangles (surfaces embedded in 4-dimensional space). Then we give concise definitions of semistrict monoidal 2-categories and braided monoidal 2-categories, and show how these may be unpac

J. Gegelia, A. Khelashvili, N. Kiknadze

It is demonstrated that in the (2+1)-dimensional topologically massive gauge theories an agreement of the Pauli-Villars regularization scheme with the other schemes can be achieved by employing pairs of auxiliary fermions with the opposite sign masses. This approach does not introduce additional violation of discrete (P and T) symmetries. Although it breaks

R. Stompor, K. M. Gorski, A. J. Banday

We investigate the consequences of flat, dark-matter dominated cosmogonies with hybrid isocurvature and adiabatic initial perturbations and with Harrison-Zel&#39;dovich primordial spectrum normalised to the $COBE$-DMR two-year measurements. We show that whilst the $COBE$-DMR data alone shows no preference for a specific admixture of these modes, acceptable c

A. Khelashvili, N. Kiknadze

One to one correspondence between the decay law of the von Neumann-Wigner type potentials and the asymptotic behaviour of the wave functions representing bound states in the continuum is established.

Claude Barrabès, Valeri Frolov

We propose a possible internal structure for a Schwarzschild black hole resulting from the creation of multiple de Sitter universes with lightlike boundaries when the curvature reaches Planckian values. The intersection of the boundaries is studied and a scenario leading to disconnected de Sitter universes is proposed. The application to the information loss

J. -S. Caux, Ian I. Kogan, A. M. Tsvelik

We study the model of (2 + 1)-dimensional relativistic fermions in a random non-Abelian gauge potential at criticality. The exact solution shows that the operator expansion contains a conserved current - a generator of a continuous symmetry. The presence of this operator changes the operator product expansion and gives rise to logarithmic contributions to th

Murray T. Batchelor, Vlad Fridkin, Yu-kui Zhou

We obtain the diagonal reflection matrices for a recently introduced family of dilute ${\rm A}_L$ lattice models in which the ${\rm A}_3$ model can be viewed as an Ising model in a magnetic field. We calculate the surface free energy from the crossing-unitarity relation and thus directly obtain the critical magnetic surface exponent $δ_s$ for $L$ odd and sur

W. R. Hix, F. -K. Thielemann

As the ultimate stage of stellar nucleosynthesis, and the source of the iron peak nuclei, silicon burning is important to our understanding of the evolution of massive stars and supernovae. Our reexamination of silicon burning, using results gleaned from simulation work done with a large nuclear network (299 nuclei and more than 3000 reactions) and from inde

S. Schindler

We present a selection of ROSAT results on the morphology, the evolution, and the masses of galaxy clusters and groups. ROSAT provides the first complete X-ray view on the Virgo cluster: it reveals a complex structure similar to the optical appearance. Indications for ongoing evolution is found in a number of clusters traced both by the surface brightness di

Somnath Bharadwaj

We use the BBGKY hierarchy equations to calculate, perturbatively, the lowest order nonlinear correction to the two point correlation and the pair velocity for Gaussian initial conditions in a critical density matter dominated cosmological model. We compare our results with the results obtained using the hydrodynamic equations which neglect pressure and we f

Dmitriy Palatnik

This paper has been withdrawn due to submission of subsequent versions as a new preprint

Alan R. Steif

Time-symmetric initial data for two-body solutions in three dimensional anti-deSitter gravity are found. The spatial geometry has constant negative curvature and is constructed as a quotient of two-dimensional hyperbolic space. Apparent horizons correspond to closed geodesics. In an open universe, it is shown that two black holes cannot exist separately, but

Xuemin Jin, B. K. Jennings

The quark-meson coupling (QMC) model for nuclear matter, which describes nuclear matter as non-overlapping MIT bags bound by the self-consistent exchange of scalar and vector mesons is modified by the introduction of a density dependent bag constant. The density dependence of the bag constant is related to that of the in-medium effective nucleon mass through

Paulo F. Bedaque

We compute the finite temperature pole mass shifts of the octet and decuplet baryons using heavy baryon chiral perturbation theory and the 1/N_c expansion, where N_c is the number of QCD colors. We consider temperatures of the order of the pion mass m_π, and truncate the chiral and 1/N_c expansions assuming that m_π\sim 1/N_c. There are three scales in the p

H. Kleinert

We formulate a new quantum equivalence principle by which a path integral for a particle in a general metric-affine space is obtained from that in a flat space by a non-holonomic coordinate transformation. The new path integral is free of the ambiguities of earlier proposals and the ensuing Schrödinger equation does not contain the often-found but physically

Denis V. Juriev

Isotopic pairs and their representations are considered in a general framework of the vector superalgebra. Numerous examples of finite-dimensional and infinite-dimensional isotopic pairs are discussed. Several types of their representations are analysed. Applications to physics and relations to other mathematical objects are specified. Some curious combinato

B. Feigin. F. Malikov

We define a new modular functor based on Kac-Wakimoto admissible representations and the corresponding D-module on the moduli space of rank 2 vector bundles with parabolic structure. A new fusion functor arises which is related to representation theory of the pair &#34;osp(1|2),sl(2)&#34; in the same way as the fusion functor for the Virasoro algebra is rela

David Tsiklauri

A phenomenon analogous to the conical refraction widely known in the crystalooptics and crystaloacoustics is discovered for the magnetohydrodynamical waves in the collisionless plasma with anisotropic thermal pressure. Angle of the conical refraction is calculated for the medium under study which is predicted to be $18^{\circ}26^{\prime}$. Possible experimen

Bao-An Li, Che Ming Ko

Within the framework of a relativistic transport model (ART) for heavy-ion collisions at AGS energies, we study the transverse flow of pions with respect to that of nucleons using two complementary approaches. It is found that in central collisions pions develop a weak flow as a result of the flow of baryon resonances from which they are produced. On the oth