March 1994 arXiv papers — page 8

J. O. Madsen, E. Ragoucy

Recently the quantum hamiltonian reduction was done in the case of general $s\ell(2)$ embeddings into Lie algebras and superalgebras. In this paper we extend the results to the quantum hamiltonian reduction of $N=1$ affine Lie superalgebras in the superspace formalism. We show that if we choose a gauge for the supersymmetry, and consider only certain equival

R. Jackiw, V. P. Nair

In their recent letter, Chaichian et.~al. present a Lagrangian for a massive ($m$) point particle on the plane, with which they claim to realize anyon statistics. However, we find that there are some inaccuracies in their formulation and, when these are taken care of, well-known results are reproduced, which already exist in the literature.

Kazuo Ghoroku, Arne L. Larsen

The 2+1 black hole anti de Sitter solution, obtained as a special limit of the conformally exact $SL(2,R)\otimes SO(1,1)/SO(1,1)$ coset WZW model to all orders in 1/k, is investigated with respect to tachyon scattering. We calculate the off-shell reflection and transmission coefficients and we find an expression for the Hawking temperature, which in a certai

F. D. T. Smith

This paper discusses the Higgs and spinor fermion terms of the D4-D5-E6 model of a series of papers (hep-ph/9301210, hep-th/9302030, hep-th/9306011, and hep-th/9402003) an 8-dimensional spacetime is reduced to 4-dimensions. The gauge boson terms give SU(3)xSU(2)xU(1) for the color, weak, and electromagnetic forces and gravity of the MacDowell-Mansouri type,

D. A. Morris, A. Ringwald

We investigate the potential of near-future neutrino telescopes like NESTOR for searches for exotic processes in ultrahigh energy neutrino-quark scattering. (NESTOR is the acronym for NEutrinos, from Supernovae and TeV sources, Ocean Range ... a water Cherenkov detector to be constructed in the Mediterranean off the coast of Greece). We consider signatures s

P. Duloos, J. -L. Meunier

{ In this paper we present a natural and comprehensive generalisation of the standard factorial moments ($\clFq$) analysis of a multiplicity distribution. The Generalised Factorial Moments are defined for all $q$ in the complex plane and, as far as the negative part of its spectrum is concerned, could be useful for the study of infrared structure of the Stro

B. C. Allanach, S. F. King

We discuss the unification of the bottom quark and tau lepton Yukawa couplings within the framework of the next-to-minimal supersymmetric standard model. We compare the allowed regions of the $m_t$-$\tan β$ plane to those in the minimal supersymmetric standard model, and find that over much of the parameter space the deviation between the predictions of two

N. G. Stefanis, M. Bergmann

Invited talk presented at the Workshop on Quantum Field Theoretical Aspects of High Energy Physics, Kyffhäuser, Germany, September 20-24, 1993; to be published in the Proceedings.

M. Bergmann, N. G. Stefanis

We study the Brodsky-Lepage evolution equation for the nucleon and construct an eigenfunction basis by including contributions of up to polynomial order $9$. By exployting the permutation symmetry $P_{13}$ of these eigenfunctions, a basis of symmetrized Appell polynomials can be constructed in which the diagonalization of the evolution kernel is considerably

M. Bergmann, N. G. Stefanis

We give an in-depth analysis of the determination procedure of the recently proposed heterotic nucleon distribution amplitude which hybridizes the best features of the Chernyak-Ogloblin-Zhitnitsky and the Gari-Stefanis models. With respect to the QCD sum-rule constraints, optimized versions of these amplitudes are derived in terms of which a "hybridity&#

A. Wambach

We investigate the Bethe--Salpeter description of mesons in the limit where one of the constituing quarks is infinitely heavy. To recover the non--relativistic quark model out of the Bethe--Salpeter formalism it is usual to assume that the potential is instantaneous and the Fock space is reduced to $Q\bar{q}$ states. We show that in the Feynman gauge in pert

H. Fritzsch

It is argued that the constituent quarks are expected to show a non-- trivial spin and flavor structure, due to the anomalous breaking of the chiral symmetry in the U(1) sector. CERN--TH.7079/93\\

Alexander Vilenkin

Different proposals for the wave function of the universe are analyzed, with an emphasis on various forms of the tunneling proposal. The issues discussed include the equivalence of the Lorentzian path integral and outgoing-wave proposals, the definitions of the outgoing waves and of superspace boundaries, topology change and the corresponding modification of

Jemal Guven

The role of topology in the perturbative solution of the Euclidean Einstein equations about flat instantons is examined.

M Onder, R W Tucker

We analyse the classical and quantum theory of a scalar field interacting with gravitation in two dimensions. We describe a class of analytic solutions to the Wheeler-DeWitt equation from which we are able to synthesise states that give prominence to a set of classical cosmologies. These states relate in a remarkable way to the general solution of the classi

T Dereli, M Onder, R W Tucker

The question of the interpretation of Wheeler-DeWitt solutions in the context of cosmological models is addressed by implementing the Hamiltonian constraint as a spinor wave equation in minisuperspace. We offer a relative probability interpretation based on a non-closed vector current in this space and a prescription for a parametrisation of classical soluti

Arvind Borde, Alexander Vilenkin

Inflation is known to be generically eternal to the future: the false vacuum is thermalized in some regions of space, while inflation continues in other regions. Here, we address the question of whether inflation can also be eternal to the past. We argue that such a steady-state picture is impossible and, therefore, that inflation must have had a beginning.

SJ Robinson, CJ Lambert, M Jeffery

We analyze the longitudinal 4-probe conductance of mesoscopic normal and superconducting wires and predict that in the superconducting case, large negative values can arise for both the weakly disordered and localized regimes. This contrasts sharply with the behaviour of the longitudinal 4-probe conductance of normal wires, which in the localized limit is al

E. Louis, G. Chiappe, J. Galan, F. Guinea

The wavefunction renormalization in the Hubbard model is studied, by using well tested mean field tecniques. The 'orthogonality catastrophe' is shown to exist, even in 2D, for doping levels sufficiently close to half filling. The results are extended beyond mean field, by constructing delocalized wavefunctions, with the correct symmetries of the exac

Julian Borrill, Edmund J Copeland, Andrew R Liddle, Albert Stebbins

We use numerical simulations to calculate the cosmic microwave background anisotropy induced by the evolution of a global texture field, with special emphasis on individual textures. Both spherically symmetric and general configurations are analysed, and in the latter case we consider field configurations which exhibit unwinding events and also ones which do

Klaus Altmann

For an affine, toric Q-Gorenstein variety Y (given by a lattice polytope Q) the vector space T^1 of infinitesimal deformations is related to the complexified vector spaces of rational Minkowski summands of faces of Q. Moreover, assuming Y to be an isolated, at least 3-dimensional singularity, Y will be rigid unless it is even Gorenstein and dim Y=3 (dim Q=2)

A. Yu. Orlov, P. Winternitz

The relation between the $\widehat\gl(\infty)$ symmetry of the Kadomtsev-Petviashvili hierarchy and the Kac-Moody-Virasoro Lie point symmetries of the individual equations is established. The Lie point symmetries are shown to be the only local ones.

L. C. Albuquerque, C. Farina, S. J. Rabello

We use Schwinger's formula, introduced by himself in the early fifties to compute effective actions for QED, and recently applied to the Casimir effect, to obtain the partition functions for both the bosonic and fermionic harmonic oscillator.

K. J. Barnes, D. A. Ross, R. D. Simmons

We construct in a manifestly supersymmetric form the leading and subleading terms in momentum for an effective supersymmetric chiral Lagrangian in terms of complex pions and their superpartners. A soft supersymmetry breaking term is included and below the supersymmetry breaking scale the Lagrangian reduces to the usual bosonic chiral Lagrangian in terms of r

Subenoy Chakraborty, Peter Peldan

We introduce a gauge and diffeomorphism invariant theory on the Yang-Mills phase space. The theory is well defined for an arbitrary gauge group with an invariant bilinear form, it contains only first class constraints, and the spacetime metric has a simple form in terms of the phase space variables. With gauge group $SO(3,C)$, the theory equals the Ashtekar

M. Beneke, V. M. Braun

We study the asymptotic behaviour of the perturbative series in the heavy quark effective theory (HQET) using the $1/N_f$ expansion. We find that this theory suffers from an {\it ultraviolet} renormalon problem, corresponding to a non-Borel-summable behaviour of perturbation series in large orders, and leading to a principal nonperturbative ambiguity in its

Jeff M. Byers, Michael E. Flatte'

Interference effects on the transport through two localized tunnel junctions on the surface of a well-grounded sample reveal intrinsic spatial correlations characteristic of the uncoupled sample. Differential conductances of the two-junction probe are related to the spatial correlations of both normal and superconducting samples. For a superconducting sample

Edward W. Kolb, Sharon L. Vadas

Within an expansion in slow-roll inflation parameters, we derive the complete second-order expressions relating the ratio of tensor to scalar density perturbations and the spectral index of the scalar spectrum. We find that ``corrections'' to previously derived formulae can dominate if the tensor to scalar ratio is small. For instance, if $V V'&#

Didier A Depireux, Jeremy Schiff, U de Montreal, Bar Ilan

We present two extensions of Wilson's explanation of the Miura map from MKdV to KdV. In the first we explain the map of Svinolupov et al from a certain UrKdV-like equation to KdV, and in the second we explain Konopelchenko's map from the modified KP equation to KP. In the course of the latter we introduce an ``UrKP'' system, with an infinite

Rodolfo Gambini

We review the application of the loop representation to gauge theories and general relativity. The emphasis lies on exhibiting the loop calculus techniques, and their application to the canonical quantization. We discuss the role that knot theory and loop coordinates play in the determination of nondegenerate quantum states of the gravitational field.

A. Yu. Orlov, P. Winternitz

The relation between the $\widehat{\Sl}(\infty)$ algebra of flows commuting with the KP hierarchy and the Kac-Moody-Virasoro Lie point symmetries of individual equations is established. This is used to calculate the point symmetries for all equations in the hierarchy.

P. Winternitz, G. Rideau

The representation theory of the quantum group su$_q(2)$ is used to introduce $q$-analogues of the Wigner rotation matrices, spherical functions, and Legendre polynomials. The method amounts to an extension of variable separation from Laplace equations to certain differential-dilation equations.

Anjan Kundu

A new integrable class of quantum models representing a family of different discrete-time or relativistic generalisations of the periodic Toda chain (TC), including that of a recently proposed classical close to TC model [7] is presented. All such models are shown to be obtainable from a single ancestor model at different realisations of the underlying quant

D. B. DeLaney, S. Jadach, Ch. Shio, G. Siopsis

We extend the methods of Yennie, Frautschi and Suura (YFS) to compute, via Monte Carlo methods, the effects of multiple gluon emission in the processes $q+q'\to q''+q'''+n(G)$, where $G$ is a soft gluon. We show explicitly that the infrared singularities in the respective simulations are canceled to all orders in $α_s$. Some discussio

Tom Banks, Yosef Nir, Nathan Seiberg

We reconsider the massless up quark solution of the strong CP problem. We show that an anomaly free horizontal symmetry can naturally lead to a massless up quark and to a corresponding accidental anomalous symmetry. Reviewing the controversy about the phenomenological viability of $m_u=0$ we conclude that this possiblity is still open and can solve the stron

D. G. Lee, R. N. Mohapatra

The simplest scenario for the three known light neutrinos that fits the solar and atmospheric neutrino deficit and a mixed dark matter (MDM) picture of the universe requires them to be highly degenerate with $m_ν \sim$ 1 - 2 eV. We propose an SO(10) grand unified model with an S$_{4}$-horizontal symmetry that leads naturally to such a scenario. An explicit n

Matthias Jamin, Antonio Pich

The 2--point functions for $ΔS=1$ current-current and QCD-penguin operators, as well as for the $\ds$ operator, are calculated at the next-to-leading order. The calculation is performed in two different renormalization schemes for $γ_5$, and the compatibility of the results obtained in the two schemes is verified. The scale- and scheme-invariant combinations

Karel V. Kuchař

The curvature coordinates $T,R$ of a Schwarz\-schild spacetime are turned into canonical coordinates $T(r), {\sf R}(r)$ on the phase space of spherically symmetric black holes. The entire dynamical content of the Hamiltonian theory is reduced to the constraints requiring that the momenta $P_{T}(r), P_{\sf R}(r)$ vanish. What remains is a conjugate pair of ca

Alan D. Rendall

This is a contribution to the forthcoming book "Canonical Gravity: {}From Classical to Quantum" edited by J. Ehlers and H. Friedrich. Ashtekar's criterion for choosing an inner product in the quantisation of constrained systems is discussed. An erroneous claim in a previous paper is corrected and a cautionary example is presented.

Alan Hopenwasser, Allan Donsig

The matrix units of a digraph algebra, A, induce a relation, known as the diagonal order, on the projections in a masa in the algebra. Normalizing partial isometries in A act on these projections by conjugation; they are said to be order preserving when they respect the diagonal order. Order preserving embeddings, in turn, are those embeddings which carry or

P. M. Murphy, M. J. Pazzani

We report on a series of experiments in which all decision trees consistent with the training data are constructed. These experiments were run to gain an understanding of the properties of the set of consistent decision trees and the factors that affect the accuracy of individual trees. In particular, we investigated the relationship between the size of a de

J. Machta, R. Greenlaw

This paper investigates the parallel complexity of several non-equilibrium growth models. Invasion percolation, Eden growth, ballistic deposition and solid-on-solid growth are all seemingly highly sequential processes that yield self-similar or self-affine random clusters. Nonetheless, we present fast parallel randomized algorithms for generating these clust

M. Karbach, K. -H. Mütter, M. Schmidt

We perform a finite size analysis of the longitudinal and transverse structure factors $S_j(p,γ,N),j=1,3$ in the groundstate of the spin-$\frac{1}{2}$ XXZ model. Comparison with the exact results of Tonegawa for the XX model yields excellent agreement. Comparison with the conjecture of Müller, Thomas, Puga and Beck reveals discrepancies in the momentum depen

S. Franz, M. Mézard

We study the off equilibrium dynamics of a mean field disordered systems which can be interpreted both as a long range interaction spin glass and as a particle in a random potential. The statics of this problem is well known and exhibits a low temperature spin glass phase with continuous replica symmetry breaking. We study the equations of off equilibrium dy

J. P. Rodriguez

A model for spin-charge separated superconductivity in two dimensions is introduced where the phases of the spinon and holon order parameters couple gauge-invariantly to a statistical gauge-field representing chiral spin-fluctuations. The model is analyzed in the continuum limit and in the low-temperature limit. In both cases we find that physical electronic

Jaichul Yi Lizeng Zhang, Geoff S Canright

We study the ground state of the two-dimensional Anderson-Hubbard model using a quantum real space renormalization group method. We obtain the phase diagram near half filling. The system is always insulating with disorder. At half filling, the system undergoes a transition from a gapless (Anderson) insulator to an incompressible (Mott-Hubbard) insulator as t

I. P. Dell'Antonio, M. J. Geller, D. G. Fabricant

We examine the relationship between the group x-ray luminosity in the 0.3-3.5 keV band and the measured velocity dispersion, and galaxy surface number density. We find definite correlations. Richer groups follow the same relation as rich clusters (cf. Quintana & Melnick 1982) with $L_x \propto σ^{4.0\pm 0.6}$, but the relation flattens for lower luminosity s

B. Edvardsson, B. Gustafsson, S. G. Johansson, D. Kiselman

Using observations of the 2496.7 A B I line with the HST GHRS at a nominal resolution of 90,000, we have found the abundance of boron of HD 140283 to be log epsilon_B (= 12 + log (N_B/N_H)) = 0.34 \pm 0.20. This result is found when a significant non-LTE effect in the formation of the B I line is taken into account. The resulting N_B/N_Be ratio is about 17 (

William Fulton, Bernd Sturmfels

The operational Chow cohomology classes of a complete toric variety are identified with certain functions, called Minkowski weights, on the corresponding fan. The natural product of Chow cohomology classes makes the Minkowski weights into a commutative ring; the product is computed by a displacement in the lattice, which corresponds to a deformation in the t

Xian Wu

We give a new residual intersection decomposition for the refined intersection products of Fulton-MacPherson. Our formula refines the celebrated residual intersection formula of Fulton, Kleiman, Laksov, and MacPherson. The new decomposition is more likely to be compatible with the canonical decomposition of the intersection products and each term in the deco