December 1994 arXiv papers — page 6

Mary K. Gaillard

It is shown that the one-loop ultraviolet divergences in renormalizable supersymmetric theories can be regulated by the introduction of heavy Pauli-Villars chiral supermultiplets, provided the generators of the gauge group are traceless in the matter representation. The procedure is extended to include supersymmetric gauged nonlinear sigma models.

S. Braune, HU Berlin

In this work we discuss an approach due to F. David to the geometry of world sheets of non-critical strings in quasiclassical approximation. The gravitational dressed conformal dimension is related to the scaling behavior of the two-point function with respect to a distance variable. We show how this approach reproduces the standard gravitational dressing in

C. Cronstrom, M. Noga

We consider evolution equations of the Lotka-Volterra type, and elucidate especially their formulation as canonical Hamiltonian systems. The general conditions under which these equations admit several conserved quantities (multi-Hamiltonians) are analysed. A special case, which is related to the Liouville model on a lattice, is considered in detail, both as

F. A. Lunev

Definition of Feynman integrals as solutions of some well defined systems of differential equations is proposed. This definition is equivalent to usual one but needs no regularization and application of $R$-operation. It is argued that proposed renormalization scheme maintains all symmetries that can be maintained in perturbative quantum field theory, and al

M. Ikehara

We take the continuum limit of the \sdeq s of the one and two matrix model without expanding them in the length of the loop. The resulting equations agree with those proposed for string field theory in the temporal gauge. We find that the loop operators are required to mix in the two matrix model case and determine the non-constant tadpole terms.

Stefan Mashkevich, Jan Myrheim, Kåre Olaussen, Ronald Rietman

We solve, by separation of variables, the problem of three anyons with a harmonic oscillator potential. The anyonic symmetry conditions from cyclic permutations are separable in our coordinates. The conditions from two-particle transpositions are not separable, but can be expressed as reflection symmetry conditions on the wave function and its normal derivat

A. N. Schellekens

A brief heuristic explanation is given of recent work with Juergen Fuchs, Beatriz Gato-Rivera and Christoph Schweigert on the construction of modular invariant partition functions from Galois symmetry in conformal field theory. A generalization, which we call quasi-Galois symmetry, is also described. As an application of the latter, the invariants of the exc

Vladan Lucic

An algorithm is presented that formalizes different steps in a classical Supersymmetric (SUSY) calculation. Based on the algorithm Dill, a symbolic software package, that can perform the calculations, is developed in the Mathematica programming language. While the algorithm is quite general, the package is created for the 4-D, N=1 model. Nevertheless, with l

Savas Dimopoulos

The measured value of the weak mixing angle is, at present, the only precise experimental indication for physics beyond the Standard Model. It points in the direction of Unified Theories with Supersymmetric particles at accessible energies. We recall the ideas that led to the construction of these theories in 1981.

S. M. Bilenky, C. Giunti

We present the results of a solar model independent analysis of the existing solar neutrino data in the case of $ν_{e}\toν_{μ(τ)}$ MSW transitions. We considered two cases. In the first case no assumptions on the values of the total fluxes of neutrinos from all reactions have been made. In the second case we constrained the values of the neutrino fluxes with

Lynne H. Orr, T. Stelzer, W. J. Stirling

We present a complete calculation of the matrix elements for the processes $q \bar q, gg \to b W^+ \bar b W^- g$ and $qg \to b W^+ \bar b W^- q$ which are relevant for the study of events with an additional jet in $t \bar t$ production at the Tevatron $p \bar p $ collider. Our calculation includes (i) the contributions from gluons emitted during the top prod

A. Abd El-Hady, K. S. Gupta, A. J. Sommerer, J. Spence

We calculate the Isgur-Wise function from the solutions of the Bethe-Salpeter equations. The shape of the Isgur-Wise function thus calculated is a prediction of the Bethe-Salpeter equations and does not depend on undetermined parameters. We develop an analytical approximation to our Isgur-Wise function in the form $ξ( ω) = η[ 1 - \frac{ρ^2}η (ω- 1) + a (ω- 1

Nina Byers

A simple extension of the QCD inspired potential model which includes dynamical quarks first proposed by Eichten et al. is remarkably successful in accounting both for the observed narrow state heavy quarkonium spectroscopy and experimental data on threshold production of charmed and B mesons in e+e- annihilation. In addition to this model, a variant of it c

A. Patrascioiu, E. Seiler

It is shown that perturbation theory in $2D$ nonlinear $σ$-models as well gauge theories in dimension $D\geq 2$ produces answers that depend on boundary conditions even after the infinite volume limit has been taken. This unphysical phenomenon occurs only in the non-Abelian versions of those models, starting at $O(1/β^2)$. It is not present in the true (nonp

Victor Matveev, Robert Shrock

We study complex-temperature properties of the uniform and staggered susceptibilities $χ$ and $χ^{(a)}$ of the Ising model on the honeycomb lattice. From an analysis of low-temperature series expansions, we find evidence that $χ$ and $χ^{(a)}$ both have divergent singularities at the point $z=-1 \equiv z_{\ell}$ (where $z=e^{-2K}$), with exponents $γ_{\ell}&

Weonjong Lee, Markus Klomfass

There are at least two methods to calculate $ B_K $ with staggered fermions: one is the two spin trace formalism and the other is the one spin trace formalism. We have performed numerical simulations on a $ 16^3 \times 40 $ lattice in full QCD with $ β= 5.7 $ and a dynamical quark mass 0.01 in lattice units. We try various sources to select only the pseudo-G

H. Markum, W. Sakuler, S. Thurner

We analyze the vacuum structure with respect to magnetic monopoles of quenched QCD in the presence of static color sources. Distributions of the monopole density around static quarks and mesons are computed in both phases of QCD. We observe a suppression of the monopole density in the vicinity of external sources. In the confinement phase the density of colo

W. Beirl, P. Homolka, B. Krishnan, H. Markum

A new method for nonperturbative investigations of quantum gravity is presented in which the simplicial path integral is approximated by the partition function of a spin system. This facilitates analytical and numerical computations considerably. In two dimensions equivalence to an Ising model with ternary couplings is recovered. First simulations in four di

K. Kajantie

This talk summarises recent results on lattice Monte Carlo studies of finite T electroweak phase transition. Particular attention is given to the 3d effective theory approach, replacing the full 4d theory by a three dimensional effective theory of the modes constant in imaginary time.

R. Enomoto et al

The fine-mesh phototube is one type of photodetector which can be used under a strong magnetic field. For an aerogel readout, the single-photon detection efficiency should be close to 100\% in order to identify particle species. We carried out a feasibility study of single-photon counting using fine-mesh phototubes, and obtained a possible solution.

F. Abe

We present a study of $W+$multijet events that compares the kinematics of the observed events with expectations from direct QCD $W+$jet production and from production and decay of top quark pairs. The data were collected in the 1992-93 run with the Collider Detector at Fermilab from 19.3 pb$^{-1}$ of proton-anti proton collisions at $\sqrt{s}=1.8$ TeV. From

G. Sardanashvily

In the Lagrangian field theory, one gets different identities for different stress energy-momentum tensors, e.g., canonical energy-momentum tensors. Moreover, these identities are not conservation laws of the above-mentioned energy-momentum tensors in general. In the framework of the multimomentum Hamiltonian formalism, we have the fundamental identity whose

Jose A. Cuesta, Angel Sanchez, y Francisco Dominguez-Adame

We theoretically study the subband structure of single Si $δ$-doped GaAs inserted in a quantum well and subject to an electric field applied along the growth direction. We use an efficient self-consistent procedure to solve simultaneously the Schrödinger and Poisson equations for different values of electric field and temperature. We thus find the confining

P. L. Krapivsky, S. Redner, F. Leyvraz

The kinetics of the annihilation process, $A+A\to 0$, with ballistic particle motion is investigated when the distribution of particle velocities is {\it discrete}. This discreteness is the source of many intriguing phenomena. In the mean field limit, the densities of different velocity species decay in time with different power law rates for many initial co

N. Dupuis

At high magnetic field, the semiclassical approximation which underlies the Ginzburg-Landau (GL) theory of the mixed state of type II superconductors breaks down. In a quasi-1D superconductor (weakly coupled chains system) with an {\it open Fermi surface}, a high magnetic field stabilizes a cascade of superconducting phases which ends in a strong reentrance

Gunter M. Schütz

We study a 12-parameter stochastic process involving particles with two-site interaction and hard-core repulsion on a $d$-dimensional lattice. In this model, which includes the asymmetric exclusion process, contact processes and other processes, the stochastic variables are particle occupation numbers taking values $n_{\vec{x}}=0,1$. We show that on a 10-par

David Lancaster, Enzo Marinari, Giorgio Parisi

We consider the mean field theory of the Random Field Ising Model obtained by weighing the many solutions of the mean field equations with Boltzmann-like factors. These solutions are found numerically in three dimensions and we observe critical behavior arising from the weighted sum. The resulting exponents are calculated.

Jan R. Engelbrecht, Kevin S. Bedell

We study the properties of Fermi Liquids with the microscopic constraint of a local self-energy. In this case the forward scattering sum-rule imposes strong limitations on the Fermi-Liquid parameters, which rule out any Pomeranchek instabilities. For both attractive and repulsive interactions, ferromagnetism and phase separation are suppressed. Superconducti

R. Fehrenbacher, M. R. Norman

A BCS model characterized by a phenomenological pair potential with on-site ($V_0$), nearest ($V_1$), and next nearest ($V_2$) neighbour coupling constants, and an empirical quasiparticle dispersion taken from angle-resolved photoemission spectra is considered. The model can consistently explain the experimental data concerning the pair state of the hole dop

Gordon Baym

We analyze the stability of the vortex lattice in a rotating superfluid against thermal fluctuations associated with the long-wavelength Tkachenko modes of the lattice. Inclusion of only the two-dimensional modes leads formally to instability in infinite lattices; however, when the full three-dimensional spectrum of modes is taken into account, the thermally

T. P. Devereaux

A theory for the effect of impurity scattering on electronic Raman scattering in unconventional superconductors is presented. The impurity dependence of the the spectra can be used to to distinguish between conventional (anisotropic $s-$wave) or unconventional ($d$-wave) energy gaps, and excellent agreement with the data on three cuprate superconductors is s

A. Baecker, F. Steiner, P. Stifter

The spectral statistics in the strongly chaotic cardioid billiard are studied. The analysis is based on the first 11000 quantal energy levels for odd and even symmetry respectively. It is found that the level-spacing distribution is in good agreement with the GOE distribution of random-matrix theory. In case of the number variance and rigidity we observe agr

Konstantin E. Bobrov, Nickolas B. Volkov, Alexander M. Iskoldsky, Vyacheslav N. Skokov

In connection with the investigations of initial stages of appearance of turbulence in the current-carrying mediums and also the investigations of relaxation oscillations in thin-film bridges of high-temperature superconductor $Y Ba_2 Cu_3 O_{7-x}$ some problems of estimation of asymptotical parameters of chaotic dynamic systems are considered. The mechanism

Bohdan Paczyński

Traditional evidence for large amount of dark matter is based on dynamical consideration for systems with $ t_{dyn} \gg t_{obs} $. Recent observational and theoretical developments in gravitational lensing offer a much more robust determination of the mass distribution in some galaxies and their clusters, with the precision comparable to that obtainable for

Tomasz Plewa

Evolution of fast, radiative shocks in high density medium is presented. Ionizing spectra and approximate broad band light curves of the shocked gas are calculated. Emergent shock spectra, as seen by a distant observer, are obtained from photoionization models. The emergent spectra have a power-law shape $F_ν\proptoν^{-α}$ with mean spectral index $α\sim0.6-

R. N. Henriksen, Lawrence M. Widrow

We study systematically stationary solutions to the coupled Vlasov and Poisson equations which have `self-similar' or scaling symmetry in phase space. In particular, we find analytically {\it all} spherically symmetric distribution functions where the mass density and gravitational potential are strict power laws in $r$, the distance from the symmetry po

P. C. Argyres, A. O. Barvinski, V. Frolov, S. B. Giddings

Contributions from the G1 Working Group at the APS Summer Study on Particle and Nuclear Astrophysics and Cosmology in the Next Millennium, Snowmass, Colorado, June 29 - July 14, 1994. V. Frolov and L. Thorlacius: Quantum Aspects of Gravity. S.B. Giddings and L. Thorlacius: Introduction to the Information Problem. A. Strominger: Two-Dimensional Black Holes an

F. Hoyle, G. Burbidge, J. V. Narlikar

Recently Wright (1994, preprint) has criticized a paper of ours on the quasi-steady state cosmology (Hoyle et al. 1994, {\em M.N.R.A.S.,} {\bf 267,} 1007) arguing that the results from a radio source survey by Allington-Smith (1982 {\em M.N.R.A.S.,} {\bf 199,} 611) show that our model published in the paper referenced above is incorrect, and claiming farther

Ugo Bruzzo, Antony Maciocia

By using a Fourier-Mukai transform for sheaves on K3 surfaces we show that for a wide class of K3 surfaces $X$ the punctual Hilbert schemes $\Hilb^n(X)$ can be identified, for all $n\geq 1$, with moduli spaces of Gieseker stable vector bundles on $X$ of rank $1+2n$. We also introduce a new Fourier-Mukai type transform for such surfaces.

Scott R. Nollet

In this paper the author generalizes the $\E$ and $\N$-type resolutions used by Martin-Deschamps and Perrin to subschemes of pure codimension in projective space, and shows that these resolutions are interchanged by the mapping cone procedure under a simple linkage. Via these resolutions, Rao's correspondence is extended to give a bijection between even

J. M. Landsberg

We study the local differential geometry of varieties $X^n\subset \Bbb C\Bbb P^{n+a}$ with degenerate secant and tangential varieties. We show that the second fundamental form of a smooth variety with degenerate tangential variety is subject to certain rank restrictions. The rank restrictions imply a slightly refined version of Zak's theorem on linear no

Benjamin P. Lee, John Cardy

The $A + B\to 0$ diffusion-limited reaction, with equal initial densities $a(0) = b(0) = n_0$, is studied by means of a field-theoretic renormalization group formulation of the problem. For dimension $d > 2$ an effective theory is derived, from which the density and correlation functions can be calculated. We find the density decays in time as $a,b \sim C\sq

Josef A. Zuk

This article is intended to provide a pedagogical introduction to the supersymmetry method for performing ensemble-averaging in Gaussian random-matrix theory. The method is illustrated by a detailed calculation of the simplest non-trivial physical quantity, namely, the second-order correlation in the density of states for two different energies within the sp

Tengiz M. Bibilashvili

It is shown that calculation of the operator's groups product with the independent time ordering procedure in each one is important for some problems in the nonequilibrium quantum field theory at finite temperature. This problem is solved in terms of path integrals by means of time-integration contour transformation. A role of thermal ghosts for this pro

Gilad Lifschytz, Samir D. Mathur, Miguel E. Ortiz

We re-examine the semiclassical approximation to quantum gravity in the canonical formulation, focusing on the definition of a quasiclassical state for the gravitational field. It is shown that a state with classical correlations must be a superposition of states of the form $e^{iS}$. In terms of a reduced phase space formalism, this type of state can be exp

E. Mirkes, J. Ohnemus

We investigate the angular distribution of the lepton pair in the process $p \bar{p} \rightarrow γ^{\ast} + X \rightarrow \ell^+\ell^- + X$, where the virtual photon is produced at high transverse momentum. The angular distribution of the leptons is very sensitive to possible nonperturbative effects, such as a nontrivial vacuum structure of QCD, and offers a

Peter Breitenlohner, Peter Forgacs, Dieter Maison

We present analytical and numerical results for static, spherically symmetric solutions of the Einstein Yang-Mills Higgs equations corresponding to magnetic monopoles and non-abelian magnetically charged black holes. In the limit of infinite Higgs mass we give an existence proof for these solutions. The stability of the abelian extremal Reissner-Nordstrom bl

Aram Kotzinian

The quark-parton model calculation including the effects of intrinsic transverse momentum and of all six twist-two distribution functions of quarks in polarized nucleons is performed. It is demonstrated that new twist-two quark distribution functions and polarized quark fragmentation functions can be investigated in semi-inclusive DIS at leading order in $Q^

Aida X. El-Khadra

The status of Lattice QCD is reviewed with respect to results that are relevant to Standard Model phenomenology. I argue that in a few simple cases all (or almost all) systematic errors from the lattice calculation are under control. Lattice QCD calculations of quarkonia ($\bb$ and $\cc$) have yielded precise determinations of the strong coupling, $\alpha_s$

Natan Andrei, Andres Jerez

We solve the Multichannel Kondo model with channel anisotropy using the Bethe Ansatz method. The model generates energy scales, characterizing the neighborhoods of the various infrared fixed points, in correspondence to the structure of the symmetry breaking in the channel sector. The nature of these fixed points also depends on the magnitude of the impurity

Philip Candelas, Xenia de la Ossa, Sheldon Katz

Recently two groups have listed all sets of weights (k_1,...,k_5) such that the weighted projective space P_4^{(k_1,...,k_5)} admits a transverse Calabi-Yau hypersurface. It was noticed that the corresponding Calabi-Yau manifolds do not form a mirror symmetric set since some 850 of the 7555 manifolds have Hodge numbers (b_{11},b_{21}) whose mirrors do not oc

A. V. Zabrodin

We clarify the algebraic structure of continuous and discrete quasi-exactly solvable spectral problems by embedding them into the framework of the quantum inverse scattering method. The quasi-exactly solvable hamiltonians in one dimension are identified with traces of quantum monodromy matrices for specific integrable systems with non-periodic boundary condi

P. Kosiński, J. Lukierski, P. Maślanka, J. Sobczyk

We present here the general solution describing generators of \kdef \poin algebra as the functions of classical \poin algebra generators as well as the inverse formulae. Further we present analogous relations for the generators of N=1 D=4 \kdef \poin superalgebra expressed by the classical \poin superalgebra generators. In such a way we obtain the \kdef \poi

F. Lenz, M. Shifman, M. Thies

A study of two-dimensional QCD on a spatial circle with Majorana fermions in the adjoint representation of the gauge groups SU(2) and SU(3) has been performed. The main emphasis is put on the symmetry properties related to the homotopically non-trivial gauge transformations and the discrete axial symmetry of this model. Within a gauge fixed canonical framewo

J. -P. Derendinger

This contribution briefly describes some developments of the use of string symmetries and anomaly cancellation mechanisms to include string loop corrections in the construction of the low-energy effective supergravity of superstrings. (Presented at the 27th International Conference on High Energy Physics, Glasgow, July 1994)

Han-Ying Guo, Yu Cai, Hong-Bo Teng

There exist certain intrinsic relations between the ultraviolet divergent graphs and the convergent ones at the same loop order in renormalizable quantum field theories. Whereupon we present a new method, the inserter regularization method, to regulate those divergent graphs. In this letter, we demonstrate this method with the $ϕ^4$ theory and QED at the one

Sanjaye Ramgoolam

We give a simple diagrammatic algorithm for writing the chiral large $N$ expansion of intersecting Wilson loops in $2D$ $SU(N)$ and $U(N) $Yang Mills theory in terms of symmetric groups, generalizing the result of Gross and Taylor for partition functions. We prove that these expansions compute Euler characters of a space of holomorphic maps from string world

George Siopsis

We discuss one-loop electroweak corrections to the decay width of toponium. We calculate the energy-level shifts by expanding around the solution of the Bethe-Salpeter equation in the instantaneous approximation, in analogy with the positronium case. We show that first-order electroweak effects are suppressed by at least four powers of the strong coupling co

A. Bottino, N. Fornengo, G. Mignola, S. Scopel

Theoretical expectations for direct and indirect searches for relic neutralinos are presented. Complementarity among various investigation means is discussed in connection with the values of the neutralino relic abundance.

P. J. Mulders, S. J. Pollock

We compare momentum sum rules from unpolarized electroproduction and the spin sum rule for $g_1$ in polarized electroproduction, and their $Q^2$ evolution in the framework of the operator product expansion. Second order effects in $α_s$ are included. We show that in comparing the evolution of the spin sum rule with the momentum sum rule one is not overly sen

H. Spiesberger

I discuss radiative corrections due to the emission of photons from quarks which contribute to deep inelastic lepton--nucleon scattering as well as to $pp$ collisions at high energies. These corrections are dominated by quark-mass singularities which have to be absorbed into the parton distribution functions. Observable effects appear as a modification of th

Jiri Hosek, Georges Ripka

A nonminimal interaction of the gluon field with a massive antisymmetric tensor order parameter is shown to yield a vanishing dielectric function at tree level. The London-type description of this perfect diaelectric suggests a tractable non-Abelian chromodynamics of the Ginzburg-Landau type which is suitable for describing the confinement-deconfinement phas

Laurent Lellouch

After a pedagogical introduction to the calculation of weak matrix elements on the lattice, I review some of the lattice's most recent predictions concerning the weak decays of $B$-mesons. Amongst the topics covered are the determinations of the leptonic decay constant $f_B$, of the form factors relevant for semi-leptonic $B\to D(D^*)\ell\bar\nu$ decays and

V. Bernard, N. Kaiser, Ulf-G. Meißner

We present novel low--energy theorems for the P--wave multipoles $2M_{1+} + M_{1-}$, $M_{1+} -M_{1-}$, $E_{1+}$ and $L_{1\pm}$ for neutral pion electroproduction off protons. These should be very useful for the analysis of existing or future threshold data.

A. B. Lahanas, K. Tamvakis

We derive the 1-loop Renormalization Group Equations for the parameters of the Minimal Supersymmetric Standard Model (MSSM) taking into account the successive decoupling of each sparticle below its threshold. This is realized by a step function at the level of each graph contributing to the Renormalization Group Equations.

Peter N. Meisinger, Michael C. Ogilvie

Using lattice perturbation theory at finite temperature, we compute for staggered fermions the one-loop fermionic corrections to the spatial and temporal plaquette couplings as well as the leading $Z_N$ symmetry breaking coupling. Numerical and analytical considerations indicate that the finite temperature corrections to the zero-temperature calculation of A

Shailesh Chandrasekharan

We study the critical behavior of the chiral condensate near the QCD phase transition in the background of two fixed light dynamical (sea) quarks. We study the condensate for $5.245 \leq β\leq 5.3$ and $10^{-10} \leq m_{val} \leq 10$

Dong Chen

We report on the hadron mass spectrum obtained on a 16^3 x 40 lattice in full QCD at β= 5.7 using two flavors of staggered fermions with m a = 0.01. We study the effective mass plateaus for different sized sources. Our mass results are slightly lighter than our earlier 16^3 x 32 calculation. The Landau gauge Δis quite different from the Coulomb gauge Δ.

Robert D. Mawhinney

The current status of United States projects pursuing Teraflops-scale computing resources for lattice field theory is discussed. Two projects are in existence at this time: the Multidisciplinary Teraflops Project, incorporating the physicists of the QCD Teraflops Collaboration, and a smaller project, centered at Columbia, involving the design and constructio

W. Kerler, C. Rebbi, A. Weber

We present an algorithm for Monte Carlo simulations which is able to overcome the suppression of transitions between the phases in compact U(1) lattice gauge theory in 4 dimensions.

W. Kerler, C. Rebbi, A. Weber

We show that topological properties of minimal Dirac sheets as well as of currents lines characterize the phases unambiguously. We obtain the minimal sheets reliably by a suitable simulated-annealing procedure.

UKQCD Collaboration, S. J. Hands, P. W. Stephenson, A. McKerrell

We calculate correlations between hadronic current operators as a function of their spatial separation, in a quenched lattice QCD simulation at $β=6.2$ on a $24^3\times48$ lattice. The lattice fermion formulation used is that due to Sheikholeslami and Wohlert. The correlation functions are then compared with the corresponding quantities calculated in the inf

M. Goeckeler, R. Horsley, V. Linke, P. E. L. Rakow

We present new Monte Carlo results in non-compact lattice QED with staggered fermions down to m_0 = 0.005. This extends our previous investigations on the nature of the continuum limit of QED.

Laurent Lellouch

Form factors relevant for semi-leptonic $B\to D,\ D^*$ decays are obtained in quenched lattice QCD. Tests of heavy-quark symmetry as well as determinations of the Isgur-Wise function and $|V_{cb}|$ are presented.

H. Arisue, K. Tabata

We have calculated the low-temperature series for the second moment of the correlation function in $d=3$ Ising model to order $u^{26}$ and for the free energy of Absolute Value Solid-on-Solid (ASOS) model to order $u^{23}$, using the finite-lattice method.

I. Adachi et al

To identify $π^{\pm}$ and $K^{\pm}$ in the region of $1.0\sim 2.5$ GeV/c, a threshold Cherenkov counter equipped with silica aerogels has been investigated. Silica aerogels with a low refractive index of 1.013 have been successfully produced using a new technique. By making use of these aerogels as radiators, we have constructed a Cherenkov counter and have

I. Okamoto, J. Katz, R. Parentani

We point out that, contrary to signs of heat capacities, thermodynamic fluctuations are simply and unequivocally related to onset of instabilities that show up near critical points. Fluctuation theory is then applied to \Schw\ \bh s surrounded by radiation. This shows that slowly evolving \bh s along quasi-equilibrium states in cavities greater than $10^6$ P

M. F. E. de Jeu

When dealing with concrete problems in a function space on R^n, it is sometimes helpful to have a dense subspace consisting of functions of a particular type, adapted to the problem under consideration. We give a theorem that allows one to write down many of such subspaces in commonly occurring Fréchet function spaces. These subspaces are all of the form $\{

M. R. Norman, M. Randeria, H. Ding, J. C. Campuzano

Recently, high resolution angle-resolved photoemission spectroscopy has been used to determine the detailed momentum dependence of the superconducting gap in the high temperature superconductor Bi-2212. In this paper, we first describe tight binding fits to the normal state dispersion and superlattice modulation effects. We then discuss various theoretical m

Hernan A. Makse, Luis A. Nunes Amaral

We study the depinning transition for models representative of each of the two universality classes of interface roughening with quenched disorder. For one of the universality classes, the roughness exponent changes value at the transition, while the dynamical exponent remains unchanged. We also find that the prefactor of the width scales with the driving fo

Z. Pluhar, H. A. Weidenmueller, J. A. Zuk, C. H. Lewenkopf

We study the ensemble-averaged conductance as a function of applied magnetic field for ballistic electron transport across few-channel microstructures constructed in the shape of classically chaotic billiards. We analyse the results of recent experiments, which show suppression of weak localization due to magnetic field, in the framework of random-matrix the

J. M. Lopez, M. A. Rodriguez, A. Diaz-Guilera, A. Hernandez-Machado

The growth of a rough interface through a random media is modelled by a continuous stochastic equation with a quenched noise. By use of the Novikov theorem we can transform the dependence of the noise on the interface height into an effective temporal correlation for different regimes of the evolution of the interface. The exponents characterizing the roughn

P. J. Forrester

The exact normalization of a multicomponent generalization of the ground state wavefunction of the Calogero-Sutherland model is conjectured. This result is obtained from a conjectured generalization of Selberg's $N$-dimensional extension of the Euler beta integral, written as a trigonometric integral. A new proof of the Selberg integral is given, and the

Jun Zang, Joseph L Birman

We report calculated dependence of magneto-exciton energy spectrum upon electron-hole separation $d$ in Fractional Quantum Hall systems. We calculated the dependence of photoluminescence upon $d$, and we obtained the doublet structure observed recently. The Raman scattering spectrum around resonance is calculated: a robust resonance peak at $ν=1/3$ around ga

L. L. Rodrigues-Williams, M. R. S. Hawkins

Distribution and properties of QSOs behind galaxy clusters in the UKJ287 field were studied. QSOs were selected using variability criteria and are confined to $z \ge 0.4$ and $m_B \le 19.5$. No reddening or obscuration of background QSOs due to dust in clusters is detected. A statistically significant positive angular correlation between clusters ($\langle z

I. Suisalu, E. Saar

We have developed an adaptive multigrid code for solving the Poisson equation in gravitational simulations. Finer rectangular subgrids are adaptively created in locations where the density exceeds a local level-dependent threshold. We describe the code, test it in cosmological simulations, and apply it to the study of the birth and evolution of a typical pan

Mark S. Miesch, John M. Scalo

Probability density functions (pdfs) of $^{13}CO$ emission line centroid (line-of-sight, intensity-weighted average) velocities are presented for several densely sampled molecular clouds as quantitative descriptors of their underlying dynamics. Although some are approximately Gaussian in form, most of the pdfs exhibit relatively broader, often nearly exponen

G. van der Geer, M. van der Vlugt

We use the relations between quadrics, trace codes and algebraic curves to construct algebraic curves over finite fields with many points and to compute generalized Hamming weights of codes.

J. Bonca, J. Jaklic

The spin-diffusion constant of the 2D $t-J$ model is calculated for the first time using an analytical approach at high temperatures and a recently-developed numerical method based on the Lanczos technique combined with random sampling in the intermediate temperature regime. A simple relation, $σ= D_sχ$, between spin conductivity and spin diffusion is establ

B. Holdom, G. Triantaphyllou

We study the Schwinger-Dyson equation associated with a chirality- changing fermion 4-point function in a strongly-coupled $U(1)$ gauge theory. After making appropriate simplifications, we solve the equation numerically via a relaxation method. Our analysis provides an estimate of the critical coupling and it gives some indication as to the general momentum

Tze-Dan Chung, Jen-Chi Lee

We give a general formula for gauge states at the discrete momenta in Liouville theory. These discrete gauge states carry the $w_\infty$ charges. As in the case of the 26D (or 10D) string theory, they are decoupled from the correlation functions and can be considered as the symmetry parameters in the old covariant quantization of the theory.

Peter Bouwknegt, Andreas Ludwig, Kareljan Schoutens

We propose a spinon basis for the integrable highest weight modules of $\hsltw$ at levels $k\geq1$, and discuss the underlying Yangian symmetry. Evaluating the characters in this spinon basis provides new quasi-particle type expressions for the characters of these integrable modules, and explicitly exhibits the structure of an RSOS times a Yangian part, know

Michael C. Ogilvie

The properties of interfaces in non-equilibrium situations are studied by constructing a density matrix with a space-dependent temperature. The temperature gradient gives rise to new terms in the equation for the order parameter. Surface terms induced in effective actions by abrupt temperature changes provide a natural theoretical framework for understanding

Steven Kleiman, Joseph Lipman, Bernd Ulrich

Let X and Y be smooth varieties of dimensions n-1 and n over an arbitrary algebraically closed field, f:X-> Y a finite map that is birational onto its image. Suppose that f is curvilinear; that is, at every point of X, the Jacobian has rank at least n-2. For r at least 1, consider the subscheme N_r of Y defined by the (r-1)st Fitting ideal of the O_Y-module

Michael Falk, Hiroaki Terao

We study cohomology with coefficients in a rank one local system on the complement of an arrangement of hyperplanes $\A$. The cohomology plays an important role for the theory of generalized hypergeometric functions. We combine several known results to construct explicit bases of logarithmic forms for the only non-vanishing cohomology group, under some nonre

R. M. Mir -- Kasimov

The concept of the one -- dimensional quantum mechanics in the relativistic configurational space (RQM) is reviewed briefly. The Relativistic Schroedinger equation (RSE) arising here is the finite-difference equation with the step equal to the Compton wave length of the particle. The different generalizations of the Dirac -- Infeld -- Hall factorizarion meth

Matti Pitkänen

The p-adic description of Higgs mechanism in TGD framework provides excellent predictions for elementary particle and hadrons masses (hep-th@xxx.lanl.gov 9410058-62). The gauge group of TGD is just the gauge group of the standard model so that it makes sense to study the p-adic counterpart of the standard model as a candidate for low energy effective theory.

E. Z. Kuchinskii, M. V. Sadovskii, V. G. Suvorov

Self-consistent theory of electron localization in disordered systems is generalized for the case of interacting electrons. We propose and critically compare a number of possible self-consistency schemes which take into account the lowest perturbation theory contributions over the interaction. Depending on self-consistency scheme we can obtain either the con

Gilbert Weinstein

The Einstein/Maxwell equations reduce in the stationary and axially symmetric case to a harmonic map with prescribed singularities phi: R^3Σ-> H^2_C, where Sigma is a subset of the axis of symmetry, and H^2_C is the complex hyperbolic plane. Motivated by this problem, we prove the existence and uniqueness of harmonic maps with prescribed singularities phi: R

Roland Stumpf, Matthias Scheffler

Using density-functional theory we investigate several properties of Al(111), Al(100), Al(110), and stepped Al(111) surfaces. We report results of formation energies of surfaces, steps, adatoms, and vacancies. For the adsorption and diffusion of Al on flat regions of Al(111) surfaces we find the hcp site energetically slightly preferred over the fcc site. Th