July 1993 arXiv papers — page 5

Yasuhiro Okada

A constraint from $b\rightarrow sγ$ process to the minimal supersymmetric standard model is derived in the light stop region where the coupling between the lighter stop and the $Z^0$ boson vanishes due to the left-right mixing of the stop states. It is pointed out that although some region in the parameter space is excluded from this process there remains a

V. Barone, M. Genovese, N. N. Nikolaev, E. Predazzi

We discuss the effects of the $s$-channel unitarization on the $x$ and $Q^{2}$ dependence of structure functions. The unitarization is implemented at the level of photoabsorption cross sections by resorting to the light--cone wave functions of virtual photons and to the diagonalization property of the scattering matrix in a basis of Fock states of the photon

Dieter Brill, Gary Horowitz, David Kastor, Jennie Traschen

There exists an upper limit on the mass of black holes when the cosmological constant $Λ$ is positive. We study the collision of two black holes whose total mass exceeds this limit. Our investigation is based on a recently discovered exact solution describing the collision of $Q=M$ black holes with $Λ> 0$. The global structure of this solution is analyzed. W

J. J. Halliwell

This paper is concerned with two questions in the decoherent histories approach to quantum mechanics: the emergence of approximate classical predictability, and the fluctuations about it necessitated by the uncertainty principle. We consider histories characterized by position samplings at $n$ moments of time. We use this to construct a probability distribut

Naresh Dadhich, L. K. Patel, R. Tikekar

We show that the metric for the singularity free family of fluid models [3] can be obtained by a simple and natural inhomogenisation and anisotropisation procedure from Friedman--Robertson--Walker metric with negative curvature. The metric is unique for cylindrically symmetric spacetime with metric potentials being separable functions of radial and time coor

Naresh Dadhich, L. K. Patel

We study the geodesics of the singularity free metric considered in the preceding Paper I and show that they are complete. This once again demonstrates the absence of singularity. The geodesic completeness is established in general without reference to any particular matter distribution. The metric is globally hyperbolic and causally stable. The question of

Fabian H. L. Essler, Vladimir E. Korepin

We continue the study of the $u(2|2)$-supersymmetric extension of the Hubbard model in one dimension. We determine the excitation spectrum at zero temperature even in the sectors where the ground states are $u(2|2)$-descendants of Bethe states. The excitations include spinons, holons, electrons, localons (local electrons pairs, moving coherently through the

A. Lakshminarayan, N. L. Balazs

The quantization of the continous cat maps on the torus has led to rather pathological quantum objects [6]. The non-generic behaviour of this model has led some to conclude that the Correspondence Principle fails in this case [2]. In this note we introduce the quantum sawtooth models, since this is the natural family to which the cat maps belong. Thus, a sim

A. Lakshminarayan, N. L. Balazs

We introduce and study the classical and quantum mechanics of certain non hyperbolic maps on the unit square. These maps are modifications of the usual baker's map and their behaviour ranges from chaotic motion on the whole measure to chaos on a set of measure zero. Thus we have called these maps ``lazy baker maps.'' The aim of introducing these

Andrew R Liddle

The energy scale of inflation is of much interest, as it suggests the scale of grand unified physics and also governs whether cosmological events such as topological defect formation can occur after inflation. The COBE results are used to limit the energy scale of inflation at around 60 $e$-foldings from the end of inflation. An exact dynamical treatment bas

John Peacock

The majority of this paper is devoted to discrete radio sources, and their consequences for cosmology. Three main issues are considered: (i) what makes a galaxy radio loud?; (ii) what do we know about how the population of radio-loud galaxies has changed with epoch?; and (iii) what can observations of high-redshift radio galaxies tell us about general questi

N. I. Kochelev

It is shown, that specific chirality and flavor properties of the instanton-induced interaction allow us to explain the observed violation Ellis-Jaffe and Gottfried sum rules. A large value of these violations originates from the anomalous growth of the instanton-induced interaction between quarks at high energy. The new sum rule which connect the values of

Andrew Strominger

It is argued that a unitarity-violating but weakly CPT invariant superscattering matrix exists for leading-order large-$N$ dilaton gravity, if and only if one includes in the Hilbert space planckian ``thunderpop" excitations which create white holes. CPT apparently cannot be realized in a low-energy effective theory in which such states have been integra

F. Vanderseypen

We consider a cell-complex in an arbitrary Hausdorff space as a dynamical object that can be coupled to a field defined on the complex. The Langevin equation is then derived for this field. In other words, a noise-field is created resulting from the field/geometry interactions.

E. Jenkins

The hyperfine mass splittings of baryons containing a heavy quark are derived at leading order in large $N$ QCD. Hyperfine splittings either preserve or violate heavy quark spin symmetry. Previous work proves that the splittings which preserve heavy quark spin symmetry are proportional to ${\bf J}^2$ at order $1/N$, where $J$ is the angular momentum of the l

E. Jenkins

The hyperfine mass splittings of baryons in large $N$ QCD are proved to be proportional to ${\bf J}^2$. Hyperfine mass splittings are first allowed at order $1/N$ in the $1/N$ expansion.

E. Jenkins

The couplings and interactions of baryons containing a heavy quark are related by light quark spin-flavor symmetry in the large $N$ limit. The single pion coupling constant which determines all heavy quark baryon-pion couplings is equal to the pion coupling constant for light quark baryons. Light quark symmetry relations amongst the baryon couplings are viol

Roger Dashen, Aneesh V. Manohar

We prove that the 1/N corrections to the baryon axial current matrix elements are proportional to their lowest order values. This implies that the first correction to axial current coupling constant ratios vanishes, and that the $SU(2N_f)$ spin-flavor symmetry relations are only violated at second order in 1/N.

Roger Dashen, Aneesh V. Manohar

We derive a set of consistency conditions for the pion-baryon coupling constants in the large-N limit of QCD. The consistency conditions have a unique solution which are precisely the values for the pion-baryon coupling constants in the Skyrme model. We also prove that non-relativistic $SU(2N_f)$ spin-flavor symmetry (where $N_f$ is the number of light flavo

E. Granato, M. P. Nightingale

Thermal and chiral critical exponents of the fully frustrated XY model on a square-lattice are obtained from a finite-size scaling analysis of the free energy of chiral domain walls. Data were obtained by extensive Monte Carlo transfer matrix computations for infinite strips of widths up to $14$ lattice spacings. Two transfer matrices were implemented, one f

A. Lakshminarayan, N. L. Balazs

We quantise and study several versions of finite multibaker maps. Classically these are exactly solvable K-systems with known exponential decay to global equilibrium. This is an attempt to construct simple models of relaxation in quantum systems. The effect of symmetries and localization on quantum transport is discussed.

Carsten Gundlach, Richard Price adn Jorge Pullin

Problem with the figures should be corrected. Apparently a broken uuencoder was the cause.

Carsten Gundlach, Richard Price, Jorge Pullin

Problem with the figures should be corrected. Apparently a broken uuencoder was the cause.

Alfredo Poirier

We provide an effective classification of postcritically finite polynomials as dynamical systems by means of Hubbard Trees. This can be viewed as an application of the results developed in part 1 (Stony Brook IMS 1993/5).

R. W. Brown, M. E. Convery, S. A. Hotes, M. G. Knepley

Low-harmonic formulas for closed relativistic strings are given. General parametrizations are presented for the addition of second- and third-harmonic waves to the fundamental wave. The method of determination of the parametrizations is based upon a product representation found for the finite Fourier series of string motion in which the constraints are autom

P. Montague

We describe a pair of constructions of Eisenstein lattices from ternary codes, and a corresponding pair of constructions of conformal field theories from lattices which turn out to have a string theoretic interpretation. These are found to interconnect in a similar way to results for binary codes, which led to a generalisation of the triality structure relev

Ryuji Kemmoku, Satoru Saito

A $q$-discretization of \vi\ algebra is studied which reduces to the ordinary \vi\ algebra in the limit of $q \ra 1$. This is derived starting from the Moyal bracket algebra, hence is a kind of quantum deformation different from the quantum groups. Representation of this new algebra by using $q$-parametrized free fields is also given.

Thomas T. Burwick

We derive curvature counterterms in two-dimensional gravity coupled to conformal matter up to infinite order. By construction the higher-order action is equivalent to a finite first-order theory with auxiliary scalar. Due to this equivalence it shares the following remarkable properties: There is no need for gravitational dressing of the cosmological constan

E. G. Flekkoy, H. J. Herrmann

We present various Lattice Boltzmann Models which reproduce the effects of rough walls, shear thinning and granular flow. We examine the boundary layers generated by the roughness of the walls. Shear thinning produces plug flow with a sharp density contrast at the boundaries. Density waves are spontaneously generated when the viscosity has a nonlinear depend

Siegfried Grossmann, Detlef Lohse

The deviations $δζ_m$ ("intermittency corrections") from classical ("K41") scaling $ζ_m=m/3$ of the $m^{th}$ moments of the velocity differences in high Reynolds number turbulence are calculated, extending a method to approximately solve the Navier-Stokes equation described earlier. We suggest to introduce the notion of scale resolved intermi

Max Tegmark, Joseph Silk

One still cannot conclusively assert that the universe underwent a neutral phase, despite the new COBE FIRAS limit y<0.000025 on Compton y-distortions of the cosmic microwave background. Although scenarios where the very early (z=1000) ionization is thermal, caused by IGM temperatures exceeding 10000K, are clearly ruled out, there is a significant loophole f

L. Baulieu, E. Rabinovici

We consider a superconformal quantum mechanical system which has been chosen on the basis of a local BRST topological invariance. We suggest that it truly leads to topological observables which we compute. The absences of a ground state and of a mass gap are special features of this system.

M. C. Nemes, Saulo C. S. Silva

In the present contribution we propose a gedankenexperiment in which the restriction of rational values on the velocities emerges as a necessary condition from Classical Electromagnetism and Quantum Mechanics. This restriction is shown to be intimately connected to Dirac&#39;s electric charge quantization condition.

Max Tegmark, Joseph Silk, Alain Blanchard

Early photoionization of the intergalactic medium is discussed in a nearly model-independent way, in order to investigate whether early structures corresponding to rare Gaussian peaks in a CDM model can photoionize the intergalactic medium sufficiently early to appreciably smooth out the microwave background fluctuations. We conclude that this is indeed poss

P. F. González-Díaz

A semiclassical two-dimensional dilaton-gravity model is obtained by dimensional reduction of the spherically symmetric five-dimensional Einstein equations and used to investigate black hole evaporation. It is shown that this model prevents the formation of naked singularity and allows spacetime wormholes to contribute the process of formation and evaporatio

German V. Shishkin, Victor M. Villalba

In the present article we present exact solutions of the Dirac equation for electric neutral particles with anomalous electric and magnetic moments. Using the algebraic method of separation of variables, the Dirac equation is separated in cartesian, cylindrical and spherical coordinates, and exact solutions are obtained in terms of special functions.

J. L. Friar, G. L. Payne, V. G. J. Stoks, J. J. de Swart

Triton properties are calculated using new nucleon-nucleon potentials, which were fit to the world nucleon-nucleon data. All potentials are charge dependent and explicitly incorporate the mass difference between the charged and neutral pions. Three of these models have a nearly optimal chi**2 per degree of freedom and can therefore be considered as alternati

Walter Van Assche, Ingrid Vanherwegen

We consider quadrature formulas based on interpolation using the basis functions $1/(1+t_kx)$ $(k=1,2,3,\ldots)$ on $[-1,1]$, where $t_k$ are parameters on the interval $(-1,1)$. We investigate two types of quadratures: quadrature formulas of maximum accuracy which correctly integrate as many basis functions as possible (Gaussian quadrature), and quadrature

Walter Van Assche

Stieltjes&#39; work on continued fractions and the orthogonal polynomials related to continued fraction expansions is summarized and an attempt is made to describe the influence of Stieltjes&#39; ideas and work in research done after his death, with an emphasis on the theory of orthogonal polynomials.

Rodica Simion, Dennis W. Stanton

Three specializations of a set of orthogonal polynomials with ``8 different q&#39;s&#39;&#39; are given. The polynomials are identified as $q$-analogues of Laguerre polynomials, and the combinatorial interpretation of the moments give infinitely many new Mahonian statistics on permutations.

Alphonse P. Magnus

Recurrence coefficients of semi-classical orthogonal polynomials (orthogonal polynomials related to a weight function $w$ such that $w&#39;/w$ is a rational function) are shown to be solutions of non linear differential equations with respect to a well-chosen parameter, according to principles established by D. G. Chudnovsky. Examples are given. For instance

Jean Letessier

We present results on co-recursive associated Laguerre and Jacobi polynomials which are of interest for the solution of the Chapman-Kolmogorov equations of some birth and death processes with or without absorption. Explicit forms, generating functions, and absolutely continuous part of the spectral measures are given. We derive fourth-order differential equa

Tom H. Koornwinder

This is an extended abstract of a lecture held at the Conference ``Fourier and Radon transformations on symmetric spaces&#39;&#39; in honor of Professor S. Helgason&#39;s 65th birthday, Roskilde, Denmark, Sept. 10--12, 1992.

Walter Van Assche, Ann Sinap

The techniques for polynomial interpolation and Gaussian quadrature are generalized to matrix-valued functions. It is shown how the zeros and rootvectors of matrix orthonormal polynomials can be used to get a quadrature formula with the highest degree of precision.

Hans J. Haubold, Arak Mathai Mathai

The paper presents results for deriving closed-form analytic solutions of the evolution of inhomogeneities in a homogeneous spatially flat multicomponent cosmological model. Mathematical methods to derive computable forms of the perturbations are outlined.

M. Lawrence Glasser, Emilio Montaldi

A number of new definite integrals involving Bessel functions are presented. These have been derived by finding new integral representations for the product of two Bessel functions of different order and argument in terms of the generalized hypergeometric function with subsequent reduction to special cases. Connection is made with Weber&#39;s second exponent

Walter Gautschi

A collection of subroutines and examples of their uses, as well as the underlying numerical methods, are described for generating orthogonal polynomials relative to arbitrary weight functions. The object of these routines is to produce the coefficients in the three-term recurrence relation satisfied by the orthogonal polynomials. Once these are known, additi

George Gasper, Walter Trebels

The necessary multiplier conditions for Laguerre expansions derived in Gasper and Trebels \cite{laguerre} are supplemented and modified. This allows us to place Markett&#39;s Cohen type inequality \cite{cohen} (up to the $\log $--case) in the general framework of necessary conditions.

George Gasper

It is shown how sums of squares of real valued functions can be used to give new proofs of the reality of the zeros of the Bessel functions $J_α(z)$ when $α\ge -1,$ confluent hypergeometric functions ${}_0F_1(c\/; z)$ when $c>0$ or $0>c>-1$, Laguerre polynomials $L_n^α(z)$ when $α\ge -2,$ and Jacobi polynomials $P_n^{(α,β)}(z)$ when $α\ge -1$ and $ β\ge -1.$

Shalosh B. Ekhad, Doron Zeilberger

Weinstein&#39;s[2] brilliant short proof of de Branges&#39;[1] theorem can be made yet much shorter(modulo routine calculations), completely elementary (modulo Löwner theory), self contained(no need for the esoteric Legendre polynomials&#39; addition theorem), and motivated(ditto), as follows.

Anne de Médicis, Dennis W. Stanton, Dennis E. White

We describe various aspects of the Al-Salam-Carlitz $q$-Charlier polynomials. These include combinatorial descriptions of the moments, the orthogonality relation, and the linearization coefficients.

Richard A. Askey, Serge\uı K. Suslov

One more model of a q-harmonic oscillator based on the q-orthogonal polynomials of Al-Salam and Carlitz is discussed. The explicit form of q-creation and q-annihilation operators, q-coherent states and an analog of the Fourier transformation are established. A connection of the kernel of this transform with a family of self-dual biorthogonal rational functio

Richard A. Askey, Serge\uı K. Suslov

A model of a q-harmonic oscillator based on q-Charlier polynomials of Al-Salam and Carlitz is discussed. Simple explicit realization of q-creation and q-annihilation operators, q-coherent states and an analog of the Fourier transformation are found. A connection of the kernel of this transform with biorthogonal rational functions is observed.

Richard A. Askey, Natig M. Atakishiyev, Serge\uı K. Suslov

A q-version of the Fourier transformation and some of its properties are discussed.

Y. Lavi, J. Sonnenschein

We prove that all the correlation functions in the $(1,q)$ models are calculable using only the Virasoro and the $W^{(3)}$ constraints. This result is based on the invariance of correlators with respect to an interchange of the order of the operators they contain. In terms of the topological recursion relations, it means that only two and three contacts and

R. B. Mann

The classical field equations of a Liouville field coupled to gravity in two spacetime dimensions are shown to have black hole solutions. Exact solutions are also obtained when quantum corrections due to back reaction effects are included, modifying both the ADM mass and the black hole entropy. The thermodynamic limit breaks down before evaporation of the bl

E. Abdalla, M. C. B. Abdalla, J. C. Brunelli, A. Zadra

We obtain the exact Dirac algebra obeyed by the conserved non-local charges in bosonic non-linear sigma models. Part of the computation is specialized for a symmetry group $O(N)$. As it turns out the algebra corresponds to a cubic deformation of the Kac-Moody algebra. The non-linear terms are computed in closed form. In each Dirac bracket we only find highes

M. C. Nemes, Saulo C. S. Silva

We present a possible solution for the long standing problem of the incompatibility of Dirac&#39;s charge quantization condition with integer values for the angular momentum of the electromagnetic field.

Cardoso de Melo, M. C. Nemes, Saulo C. S. Silva

In the present work we argue that the usual assumption that magnetic currents possess the vector structure characteristic of electric currents may be the source of several difficulties in the theory of magnetic monopoles. We propose an {\it axial} magnetic current instead and show that such difficulties are solved. Charge quantization is shown to be intimate

G. Papadopoulos, P. K. Townsend

We determine the general scalar potential consistent with (p,q) supersymmetry in two-dimensional non-linear sigma models with torsion, generalizing previous results for special cases. We thereby find many new supersymmetric sigma models with potentials, including new (2,2) and (4,4) models.

S. Higuchi, C. Itoi, S. Nishigaki, N. Sakai

We summarize our renormalization group approach for the vector model as well as the matrix model which are the discretized quantum gravity in one- and two-dimensional spacetime. A difference equation is obtained which relates free energies for neighboring values of $N$. The reparametrization freedom in field space is formulated by means of the loop equation.

H. Aratyn, L. A. Ferreira, J. F. Gomes, A. H. Zimerman

Invariance under non-linear ${\sf {\hat W}}_{\infty}$ algebra is shown for the two-boson Liouville type of model and its algebraic generalizations, the extended conformal Toda models. The realization of the corresponding generators in terms of two boson currents within KP hierarchy is presented.

Jan Ambjorn, Charlotte F. Kristjansen

Loop equations of matrix models express the invariance of the models under field redefinitions. We use loop equations to prove that it is possible to define continuum times for the generic hermitian {1-matrix} model such that all correlation functions in the double scaling limit agree with the corresponding correlation functions of the Kontsevich model expre

H. M. Baboujian

We prove that the wave vectors of the off-shell Bethe Ansatz equation for the inhomogeneous SU(2) lattice vertex model render in the quasiclassical limit the solution of the Knizhnik-Zamolodchikov equation.

Jan Sladkowski

The proposed by Bastianelli and van Nieuwenhuizen new method of calculations of trace anomalies is applied in the conformal gauge field case. The result is then reproduced by the heat equation method. An error in previous calculation is corrected. It is pointed out that the introducing gauge symmetries into a given system by a field-enlarging transformation

Andrew Strominger

The quantum statistics of charged, extremal black holes is investigated beginning with the hypothesis that the quantum state is a functional on the space of closed three-geometries, with each black hole connected to an oppositely charged black hole through a spatial wormhole. From this starting point a simple argument is given that a collection of extremal b

F. Halzen, J. E. Jacobsen, E. Zas

We have simulated the response of a high energy neutrino telescope to the stream of low energy neutrinos produced by a supernova. The nominal threshold of such detectors is in the GeV energy range. The passage of a large flux of MeV neutrinos during a period of seconds will nevertheless be detected as an excess of single counting rates in all individual opti

Suraj N. Gupta, James M. Johnson, Wayne W. Repko

The scattering of $W$, $Z$ and Higgs bosons in the Standard Model is investigated in the region $s,m_H^2\gg m_W^2$ with no restrictions on relative sizes of $s$ and $m_H^2$, so that our results are applicable at energies below as well as above $2m_H$. We have calculated, with the inclusion of the full one-loop corrections, the scattering matrix between the s

S. Keller, J. F. Owens

Little information is known about the polarization of gluons inside a longitudinally polarized proton. We investigate the sensitivity of photoproduction experiments with both beam and target longitudinally polarized to the polarization of the gluon distribution in the proton. We study the photoproduction of jets and heavy quarks and conclude that they are bo

V. G. Bornyakov, V. K. Mitrjushkin, M. Müller-Preussker, F. Pahl

Photon correlators in $~U(1)~$ pure gauge theory for different lattice actions are considered under the Lorentz gauge condition. They are shown to depend strongly on the gauge fixing ambiguity and on the corresponding existence of Dirac sheets. For the Coulomb phase a gauge fixing algorithm is proposed which avoids Dirac sheets and allows to find the global

UKQCD Collaboration

We compare the light hadron spectrum and decay constants for quenched QCD at $β=6.2$ using an $O(a)$-improved nearest-neighbour Wilson fermion action with those obtained using the standard Wilson fermion action on the same set of 18 gauge configurations. For pseudoscalar meson masses in the range 330--800~MeV, we find no significant difference between the re

C. Barrabes, B. Boisseau, M. Sakellariadou

We derive the effective action for a domain wall with small thickness in curved spacetime and show that, apart from the Nambu term, it includes a contribution proportional to the induced curvature. We then use this action to study the dynamics of a spherical thick bubble of false vacuum (de Sitter) surrounded by an infinite region of true vacuum (Schwarzschi

Jens U. Noeckel, A. Douglas Stone, Harold U. Baranger

Linear response theory for open (infinite) systems leads to an expression for the current response which contains surface terms in addition to the usual bulk Kubo term. We show that this surface term vanishes identically if the correct order of limits is maintained in the derivation: the system size, L, must be taken to infinity before the adiabatic turn-on

M. Sandhoff, H. Pfnuer, H. U. Everts

We investigate the phase diagram and the critical properties of the adsorbate system sulphur/ruthenium(0001) in the coverage region $\frac{1}{4} < Θ< \frac{1}{3}$ by means of Monte-Carlo simulations of a simple lattice gas model on a triangular lattice. The model contains only repulsive nearest and next-nearest neighbor interactions. Combining results obtain

R. Brandenberger, H. Feldman, V. Mukhanov

A brief introduction to the gauge invariant classical and quantum theory of cosmological perturbations is given. The formalism is applied to inflationary Universe models and yields a consistent and unified description of the generation and evolution of fluctuations. A general formula for the amplitude of cosmological perturbations in inflationary cosmology i

Gerald B. Cleaver

The focus of this thesis is on (1) the role of Ka\v c-Moody (KM) algebras in string theory and the development of techniques for systematically building string theory models based on higher level ($K\geq 2$) KM algebras and (2) fractional superstrings. In chapter two we review KM algebras and their role in string theory. In the next chapter, we present two r

Yuri D. Latushkin, Stephen J. Montgomery-Smith

We present a spectral mapping theorem for continuous semigroups of operators on any Banach space $E$. The condition for the hyperbolicity of a semigroup on $E$ is given in terms of the generator of an evolutionary semigroup acting in the space of $E$-valued functions. The evolutionary semigroup generated by the propagator of a nonautonomous differential equa

J. M. Quashnock, D. Q. Lamb

We investigate clustering in the angular distribution of the 260 $γ$-ray bursts in the publicly available BATSE catalogue, using a nearest neighbour analysis and the measures of burst brightness $B$ and short time scale variability $V$ which we introduced earlier. We find that while all 260 bursts are only modestly clustered (Q-value = $1.8 \times 10^{-2}$),

J. M. Quashnock, D. Q. Lamb

We investigate the angular distribution of the $γ$-ray bursts in the publicly available BATSE catalogue, using the measures of burst brightness $B$ and short time scale ($\simless$ 0.3 s) variability $V$ which we introduced earlier. We show that the 54 type I ($\log V \le -0.8$) bursts lying in the middle brightness range 490 counts $\le B \le$ 1250 counts (

Pietro Donatis, Roberto Iengo

We consider an effective Lagrangian describing a fluid living on two-di\-men\-sio\-nal planes. The fluid self-interacts through a Chern-Simons vector potential, whose field strength is proportional to the density fluctuation. This effective Lagrangian can be related to the Anyon mean field, but can also be considered more generally to describe a universality

Darwin Chang, Wai-Yee Keung, Ivan Phillips

We consider various integrated lepton charge-energy asymmetries and azimuthal asymmetries as tests of CP violation in the process $e^-e^+ \to W^-W^+$. These asymmetries are sensitive to different linear combinations of the CP violating form factors in the three gauge boson $W^-W^+$ production vertex, and can distinguish dispersive and absorptive parts of the

Galliano Valent

The generating function of Stieltjes-Carlitz polynomials is a solution of Heun&#39;s differential equation and using this relation Carlitz was the first to get exact closed forms for some Heun functions. Similarly the associated Stieltjes-Carlitz polynomials lead to a new differential equation which we call associated Heun. Thanks to the link with orthogonal

Krzysztof Stempak, Walter Trebels

Using the standard square--function method (based on the Poisson semigroup), multiplier conditions of Hörmander type are derived for Laguerre expansions in $L^p$--spaces with power weights in the $A_p$-range; this result can be interpreted as an ``upper end point&#39;&#39; multiplier criterion which is fairly good for $p$ near $1$ or near $\infty $. A weight

Yoav Peleg

By analysing the infinite dimensional midisuperspace of spherically symmetric dust universes, and aply it to collapsing dust stars, one finds that the general quantum state is a bound state. This leads to discrete spectrum. In the case of a Schwarzschild black hole, the discrete spectrum implies Bekenstein area quantization: the area of the horizon is an int

Michael Terhoeven

Recently dilogarithm identities have made their appearance in the physics literature. These identities seem to allow to calculate structure constants like, in particular, the effective central charge of certain conformal field theories from their fusion rules. In Nahm, Recknagel, Terhoeven (1992) a proof of identities of this type was given by considering th

L. Bruecher, J. Franzkowski, D. Kreimer

To entirely determine the resulting functions of one-loop integrals it is necessary to find the correct analytic continuation to all relevant kinematical regions. We argue that this continuation procedure may be performed in a general and mathematical accurate way by using the ${\cal R}$ function notation of these integrals. The two- and three-point cases ar

Yukihisa Itoh

We study higher order approximations in the renormalization group approach to matrix models. We use constraint equations on the free energy resulting from a freedom of field redefinitionsand obtain the effective beta function for a single coupling constant to the fifth order. The fixed point and the string susceptibility exponent are shown to approach the va

S. Dalley

The technique of (discretised) light-cone quantisation, as applied to matrix models of relativistic strings, is reviewed. The case of the c=2 non-critical bosonic string is discussed in some detail to clarify the nature of the continuum limit. Futher applications for the technique are then outlined. (To appear in proceedings of the NATO Advanced Workshop on

F. Halzen

Although we have a theory of strong interactions, its implications for the physics of average hadron collisions, which is the focus of this series of conferences, are far from obvious. QCD has nevertheless been a very powerful guide and I will argue that a consensus description of ``soft&#34; hadronic physics is emerging at least at the phenomenological leve

Paul Graham, Neil Turok, Philip Lubin, Jeff Schuster

We propose a set of statistics $S_q$ for detecting non-gaussianity in CMBR anisotropy data sets. These statistics are both simple and, according to calculations over a space of linear combinations of three-point functions, nearly optimal at detecting certain types of non-gaussian features. We apply $S_3$ to the UCSB SP91 experiment and find that the mean of

Xiangdong Ji

We define a number of quark fragmentation functions for spin-0, -1/2 and -1 hadrons, and classify them according to their twist, spin and chirality. As an example of their applications, we use them to analyze semi-inclusive deep-inelastic scattering on a transversely polarized nucleon.

Xiangdong Ji

We consider the matrix elements of the left-handed flavor-conserving four-quark operators in the nucleon and pion states. Using chiral symmetry, we derive relationships among these matrix elements. We argue that the $ΔI = 1/2$ rule of hyperon and kaon non-leptonic weak decay implies possible large strange-quark content in the nucleon and pion.

J. Milana, S. Nussinov, M. G. Olsson

We show that the $J/ψ\rightarrow π^{+} π^{-}$ decay is a reliable source of information for the electromagnetic form factor of the pion at $t=M_{J/ψ}^2=9.6 {\rm GeV}^2$ by using general arguments to estimate, or rather, put upper bounds on, the background processes that could spoil this extraction. We briefly comment on the significance of the resulting $F_π

Matteo Beccaria, Giuseppe Curci, Luca Galli

We continue the investigation on the applications of the Kramers equation to the numerical simulation of field theoretic models. In a previous paper we have described the theory and proposed various algorithms. Here, we compare the simplest of them with the Hybrid Monte Carlo algorithm studying the two-dimensional lattice Gross-Neveu model. We used a Symanzi

Matteo Beccaria, Giuseppe Curci

Using an operatorial formalism, we study the Kramers equation and its applications to numerical simulations. We obtain classes of algorithms which may be made precise at every desired order in the time step $ε$ and with a set of free parameters which can be used to reduce autocorrelations. We show that it is possible to use a global Metropolis test to restor

J. Fernando Barbero, Madhavan Varadarajan

The Ashtekar formulation of 2+1 gravity differs from the geometrodynamical and Witten descriptions when the 2-metric is degenerate. We study the phase space of 2+1 gravity in the Ashtekar formulation to understand these degenerate solutions to the field equations. In the process we find two new systems of first class constraints which describe part of the de

V. Barzykin, D. Pines, A. Sokol, D. Thelen

We discuss the crossover from the quantum critical, $z\!=\!1$, to the quantum disordered regime in high-T$_c$ materials in relation to the experimental data on the nuclear relaxation, bulk susceptibility, and inelastic neutron scattering. In our scenario, the spin excitations develop a gap $Δ\!\sim\!1/ξ$ well above T$_c$, which is supplemented by the quasipa

Gen Tatara, Hidetoshi Fukuyama

The macroscopic quantum tunneling of a planar domain wall in a ferromagnetic metal is studied based on the Hubbard model. It is found that the ohmic dissipation is present even at zero temperature due to the gapless Stoner excitation, which is the crucial difference from the case of the insulating magnet. The dissipative effect is calculated as a function of

J. K. Freericks, H. Monien

The first reliable analytic calculation of the phase diagram of the bose gas on a $d$-dimensional lattice with on-site repulsion is presented. In one dimension, the analytic calculation is in excellent agreement with the numerical Monte Carlo results. In higher dimensions, the deviations from the Monte Carlo calculations are larger, but the correct shape of

R. N. Mohapatra, X. Zhang

In a SUSY theory with a spontaneously broken global symmetry, G, if the scale of SUSY breaking, $M_s$ is smaller than the scale $M_G$ of the global symmetry, the Nambu-Goldstone boson, $χ$ is accompanied by two massive superpartners ( a fermionic, $Ψ_χ$ and a scalar $σ_χ$) with mass of order $M_s$. Cosmological considerations imply stringent constraints on t