April 1994 arXiv papers — page 6

A. I. Vainshtein, V. I. Zakharov

We consider large-order perturbative expansions in QED and QCD. The coefficients of the expansions are known to be dominated by the so called ultraviolet (UV) renormalons which arise from inserting a chain of vacuum-polarization graphs into photonic (gluonic) lines. In large orders the contribution is associated with virtual momenta $k^2$ of order $Q^2e^n$ w

W. Balogh, R. Bieber, H. Oberhummer, T. Rauscher

The importance of direct capture for (n,$γ$)--reactions on intermediate-- and heavy--mass target nuclei occuring in the s-- and r--process is investigated. It is shown that the direct mechanism is non--negligible for magic and neutron rich target nuclei. For some double magic and neutron rich nuclei in the r--process direct capture is even the dominant react

Erik Koelink, René F. Swarttouw

An addition and product formula for the Hahn-Exton $q$-Bessel function, previously obtained by use of a quantum group theoretic interpretation, are proved analytically. A (formal) limit transition to the Graf addition formula and corresponding product formula for the Bessel function is given.

P. Aspinwall

The idea of minimum distance, familiar from R <-> 1/R duality when the string target space is a circle, is analyzed for less trivial geometries. The particular geometry studied is that of a blown-up quotient singularity within a Calabi-Yau space and mirror symmetry is used to perform the analysis. It is found that zero distances can appear but that in many c

S. J. Fuchs, M. G. Schmidt, C. Schweigert

We investigate the structure of the configuration space of gauge theories and its description in terms of the set of absolute minima of certain Morse functions on the gauge orbits. The set of absolute minima that is obtained when the background connection is a pure gauge is shown to be isomorphic to the orbit space of the pointed gauge group. We also show th

S. Dalley

The space-time light-cone Hamiltonian P^- of large-N matrix models for dynamical triangulations may be viewed as that of a quantum spin chain and analysed in a mean field approximation. As N -> infinity, the properties of the groundstate as a function of the bare worldsheet cosmological constant exhibit a parton phase and a critical string phase, separated b

M. Rausch de Traubenberg

Classification of finite dimensional representations of the q-deformed Heisenberg algebra $H_q(3)$ is made by the help of Clifford algebra of polynomials and generalized Grassmann algebra. Special attention is paid when $q$ is a primitive $n$ root of unity. As a further application we obtain finite dimensional representations of $ sl(2)_q$ using its embeddin

T. Eguchi, H. Kanno

The Toda lattice hierarchy is discussed in connection with the topological description of the $c=1$ string theory compactified at the self-dual radius. It is shown that when special constraints are imposed on the Toda hierarchy, it reproduces known results of the $c=1$ string theory, in particular the $W_{1+\infty}$ relations among tachyon correlation functi

A. Mishra, H. Mishra, Varun Sheel, S. P. Misra

We consider here the vacuum structure in QCD with both quark and gluon condensates and a variational ansatz for the ground state. The method is nonperturbative using only equal time algebra for the field operators. We then find that a constrained energy minimisation of the Hamiltonian leads to a QCD vacuum with both quark and gluon condensates for $α_s > α_c

P. Nason, B. W. Webber

We propose a method for measuring the hadron charge asymmetry in $\ee$ collisions which is based upon the fragmentation function formalism, and is largely independent of modelling of fragmentation effects. Furthermore, in this method, QCD radiative corrections can be accounted for in a systematic way.

Chris Kolda, Leszek Roszkowski, James D. Wells, G. L. Kane

We examine the Constrained Minimal Supersymmetric Standard Model (CMSSM) with an additional requirement of strict b - tau unification in the region of small tan(beta). We find that the parameter space becomes completely limited below about 1 TeV by physical constraints alone, without a fine-tuning constraint. We study the resulting phenomenological consequen

F. Halzen, J. E Jacobsen

High energy particles are produced by the annihilation of dark matter particles in our galaxy. These are presently searched for using balloon-borne antiproton and positron detectors and large area, deep underground neutrino telescopes. Dark matter particles, trapped inside the sun, are an abundant source of such neutrinos. From both the cosmological and part

J. E. Horvath

We consider the effects of the curvature energy term on thermal strange quark matter nucleation in dense neutron matter. Lower bounds on the temperature at which this process can take place are given and compared to those without the curvature term.

J. Bohacik, P. Presnajder

Heavy quark potential in the continuum theory at finite temperature is calculated in different phases by using the Polyakov loop as the order parameter. We find the linearly rising potential in the confinement phase, the Debye screened potential in the deconfinement phase and the perturbative $r^{-2}$ dependence at very high temperatures. Within the approxim

J. A. Grifols, S. Tortosa

In this paper we survey the effects of residual long-range forces associated to $γ_5$-spin dependent-couplings of fermions to massless bosons exerted by unpolarised bulk matter over macroscopic distances. We establish that such forces with behaviour proportional to $R^{-6}$ do indeed exist. They arise as a quantum mechanical effect due to simultaneous exchan

B. G. Preparata, She-Sheng XUE

We analyse the problem of the generation of mass in the gauge boson sector on the (Planck) lattice. We obtain a dynamical scenario quite similar to the popular Higgs-mechanism, with the important difference that no Higgs-type excitation is present in our theory. By fixing the mass of the $Z^\circ$-boson and the renormalized gauge couplings at their experimen

A. M. Green, C. Michael, M. E. Sainio

Energies of four-quark systems have been extracted in a static quenched SU(2) lattice Monte Carlo calculation for six different geometries, both planar and non-planar, with $β=2.4$ and lattice size $16^3\times 32$. In all cases, it is found that the binding energy is greatly enhanced when the four quarks can be partitioned in two ways with comparable energie

E. Woolgar

Within the general class of Asymptotically Anti-de Sitter spacetimes that are asymptotic to the A-de-S Schwarzschild metric, we give a simple positive mass theorem based on arguments from causal structure. A general result for all asymptotically A-de-S spacetimes will be given elsewhere.

E. Woolgar

We use the formulation of asymptotically anti-de Sitter boundary conditions given by Ashtekar and Magnon to obtain a coordinate expression for the general asymptotically AdeS metric in a neighbourhood of infinity. From this, we are able to compute the time delay of null curves propagating near infinity. If the gravitational mass is negative, so will be the t

R. Aldrovandi, G. E. A. Matsas, S. F. Novaes, D. Spehler

The helicity flip of a spin-${\textstyle \frac{1}{2}}$ Dirac particle interacting gravitationally with a scalar field is analyzed in the context of linearized quantum gravity. It is shown that massive fermions may have their helicity flipped by gravity, in opposition to massless fermions which preserve their helicity.

Y. Berk, A. Kamenev, A. Palevski, L. N. Pfeiffer

We present a microscopical theory and experimental results concerning resistance resonance in two tunneling coupled quantum wells with different mobilities. The shape of the resonance appears to be sensitive to the small angle scattering rate on remote impurities and to the electron--electron scattering rate. This allows the extraction of scattering paramete

G. Baskaran

We study the perturbative correction to the ground state energy eigenvalue of a 2-dimensional dilute fermi gas with weak short-range two body repulsion. From the structure of the energy shift we infer the presence of an induced two body long range repulsive interaction $ {\displaystyle {1\over{r^2}} }$ among the constituent electrons indicating a potential i

T. J. Hagenaars, P. H. E. Tiesinga, J. E. van Himbergen, Jorge V. José

When a vortex in a two-dimensional Josephson junction array is driven by a constant external current it may move as a particle in a viscous medium. Here we study the nature of this viscous motion. We model the junctions in a square array as resistively and capacitively shunted Josephson junctions and carry out numerical calculations of the current-voltage ch

M. Basler, W. Krech, K. Yu. Platov

Within the RSJ model we performed an analytical and numerical investigation of SQUID cells consisting of two Josephson junctions shunted by an extremely small inductance leading to strong coupling of the elements. Contrary to the well-known behavior of cells shunted by a high inductance voltage phases of the junctions are locked with very small phase differe

Mark Johnson

This paper shows how to apply memoization (caching of subgoals and associated answer substitutions) in a constraint logic programming setting. The research is is motivated by the desire to apply constraint logic programming (CLP) to problems in natural language processing that involve (constraint) interleaving or coroutining, such as GB and HPSG parsing.

Sergio Campana

Paczyński (1986) suggested that ``dark&#34; objects in the halo of our Galaxy could enhance the luminosity of foreground stars, acting as gravitational microlenses. Such events has been recently reported by different collaborations. We assume that these microlensing events are produced by baryonic objects in the halo of our Galaxy. Rather than adopting a mea

A. Stange, W. Marciano, S. Willenbrock

We consider the search for the Higgs boson at a high-luminosity Fermilab Tevatron, an upgraded Tevatron of energy 3.5 TeV, and the CERN Large Hadron Collider, via $WH/ZH$ production followed by H -> bb~ and leptonic decay of the weak vector bosons. We show that each of these colliders can potentially observe the standard Higgs boson in the intermediate-mass

Moti Gitik

Suppose that kappa is a singular cardinal of cofinality omega and GCH holds. Assume that for every n<omega the set of alphas with o(alpha)>= alpha^{+n} is unbounded in kappa.Then there is a cardinal preserving extension satisfying 2^kappa=kappa^++ and GCH below kappa. By a result of W. Mitchell and the author the assumptions are optimal.

Dae Yup Song

The large-$N$ nonlinear $O(N)$, $CP^{N-1}$ $σ$ models are studied on $R^2 \times S^1$. The $N$-components scalar fields of the models are supposed to acquire a phase $e^{i2πδ}$ $(0\leq δ<1)$, along the circulation of the circle, $S^1$. We evaluate the effective potentials to the leading order of the $1/N$ expansion. It is shown that, on $R^2\times S^1$ the $

A. Barroso, Joao P. Silva

We present a model which supplements the Standard Electroweak Model with three right-handed neutrinos and one extra scalar doublet which does not develop a vacuum expectation value. With the aid of a discrete symmetry the neutrinos are kept strictly massless. This model has several interesting features. It has unsuppressed lepton flavour violating processes,

David Garfinkle, M. A. Melvin

In this paper we apply the techniques which have been developed over the last few decades for generating nontrivially new solutions of the Einstein-Maxwell equations from seed solutions for simple spacetimes. The simple seed spacetime which we choose is the &#34;magnetic universe&#34; to which we apply the Ehlers transformation. Three interesting non-singula

Feliks Przytycki

Let $H^d$ be the set of all rational maps of degree $d\ge 2$ on the Riemann sphere which are expanding on Julia set. We prove that if $f\in H^d$ and all or all but one critical points (or values) are in the immediate basin of attraction to an attracting fixed point then there exists a polynomial in the component $H(f)$ of $H^d$ containing $f$. If all critica

Ulrich Meyer

We give a systematic account of the exterior algebra of forms on q-Minkowski space, introducing the q-exterior derivative, q-Hodge star operator, q-coderivative, q-Laplace-Beltrami operator and the q-Lie-derivative. With these tools at hand, we then give a detailed exposition of the q-d&#39;Alembert and q-Maxwell equation. For both equations we present a q-m

A. P. Kobushkin, A. I. Syamtomov, C. F. Perdrisat, V. Punjabi

The polarization observables in the elastic scattering of polarized deuterons on a polarized hydrogen target, with measurement of the recoil proton polarization, are considered. The observables are calculated in the one-neutron exchange approximation, for the special case of backward scattering ($θ_{c.m.} = 180^{\circ}$). Several new relations between polari

J. F. Gunion, T. Han

We compute an array of Standard Model Higgs boson ($\hsm$) signals and backgrounds for a possible upgrade of the Tevatron to $E_{\rm cm}=4\tev$. Taking $\mt\geq 140\gev$, and assuming a total accumulated luminosity of $L=30\fbi$, we find that a Standard Model Higgs boson with $\mhsm\lsim 110\gev$ could almost certainly be detected using the $\wpm\hsm\rta lνb

Felix Ritort

We discuss the problem of static chaos in spin glasses. In the case of magnetic field perturbations, we propose a scaling theory for the spin-glass phase. Using the mean-field approach we argue that some pure states are suppressed by the magnetic field and their free energy cost is determined by the finite-temperature fixed point exponents. In this framework

M. Grilli, C. Castellani

We investigate the effect of strong electron-electron repulsion on the electron-phonon interaction from a Fermi-liquid point of view: the strong interaction is responsible for vertex corrections, which are strongly dependent on the $v_Fq/ω$ ratio. These corrections generically lead to a strong suppression of the effective coupling between quasiparticles medi

J. L. Levy, R. B. Laughlin

This paper establishes and tests procedures which can determine the electron energy gap of the high-temperature superconductors using the $t\!-\!J$ model with spinon and holon quasiparticles obeying fractional statistics. A simpler problem with similar physics, the spin susceptibility spectrum of the spin 1/2 fractional-statistics gas, is studied. Interactio

Yue-Liang Wu

It is shown that a two-Higgs doublet model with Vacuum CP Violation and Approximate Global $U(1)$ Family Symmetries (AGUFS) may provide one of the simplest and attractive models in understanding origin and mechanisms of CP violation at the weak scale. The whole new interactions of the model are explicitly presented here. It is seen that CP violation can occu

A. Dobado, J. R. Pelaez

In this work we derive the version of the Equivalence Theorem that applies when the symmetry breaking sector of the Standard Model is described by a general chiral lagrangian. The demonstration is valid for renormalized fields for any value of the gauge parameter (in $R_{\xi}$ gauges) and any parametrization of the coset space. It is based in the absence of

Murray Gell-Mann, James B. Hartle

We consider notions of physical equivalence of sets of histories in the quantum mechanics of a closed system. We show first how the same set of histories can be relabeled in various ways, including the use of the Heisenberg equations of motion and of passive transformations of field variables. In the the usual approximate quantum mechanics of a measured subs

U. Ritschel

The non-perturbative autonomous renormalization of the scalar $Φ^4$-model is applied in the framework of stochastic quantization. I show that this requires a selective, momentum-dependent renormalization of the Onsager coefficient $λ$, a direct consequence of the characteristic wavefunction renormalization applied. As a result, I obtain a Langevin equation f

H. J. Weber

Deep inelastic structure functions for the nucleon are obtained in a constituent quark model on the light cone. In the Bjorken limit the parton model is derived. Structure functions from the hadronic tensor at the scale $μ\sim 0.25$ GeV are evolved from (0.6 GeV$)^{2}$ to $-q^{2}\sim 15$ GeV$^{2}$. The model incorporates the quark boosts, is designed to desc

Kefeng Liu

We show that a general miraculous cancellation formula, the divisibility of certain characteristic numbers and some other topologiclal results are con- sequences of the modular invariance of elliptic operators on loop spaces. Previously we have shown that modular invariance also implies the rigidity of many elliptic operators on loop spaces.

A. Ballesteros, F. J. Herranz, M. A. del Olmo, M. Santander

An embedding method to get $q$-deformations for the non--semisimple algebras generating the motion groups of $N$--dimensional flat spaces is presented. This method gives a global and simultaneous scheme of $q$-deformation for all $iso(p,q)$ algebras and for those ones obtained from them by some Inönü--Wigner contractions, such as the $N$--dimensional Euclide

Angel Ballesteros, Javier Negro

All the hermitian representations of the ``symmetric&#34; $q$-oscillator are obtained by means of expansions. The same technique is applied to characterize in a systematic way the $k$-order boson realizations of the $q$-oscillator and $su(1,1)_q$. The special role played by the quadratic realizations of $su(1,1)_q$ in terms of boson and $q$-boson operators i

D. Bernard, V. Pasquier, D. Serban

We study the $su(2)$ conformal field theory in its spinon description, adapted to the Yangian invariance. By evaluating the action of the Yangian generators on the primary fields, we find a new connection between this conformal field theory and the Calogero-Sutherland model with $su(2)$ spin. We use this connection to describe how the spinons are the quasi-p

L. Chekhov

We study scattering processes on $p$-adic multiloop surfaces represented as multiloop infinite graphs with total valence in each vertex equal $p+1$. They all are spaces of the constant negative curvature since they are quotients of the $p$-adic hyperbolic plane over free acting discrete subgroup of $PGL(2, {\bf Q}_p)$. Releasing the closed part of this graph

C. Duval, P. A. Horváthy, L. Palla

The construction and the symmetries of Chern-Simons vortices in harmonic and uniform magnetic force backgrounds found by Ezawa, Hotta and Iwazaki, and by Jackiw and Pi are generalized using the non-relativistic Kaluza-Klein-type framework presented in our previous paper. All Schrödinger-symmetric backgrounds are determined. (10 pages. PlainTex)

N. Deshpande, Xiao-Gang He, E. Keith

We study proton decay in finite supersymmetric SU(5) grand unified theories. We find that the dimension-five operators due to color triplet higgsino induce too rapid a proton decay. This behaviour can be traced to the large Yukawa couplings to the first generation that are necessary for finiteness.

A. A. Osipov

A model of the rho-meson as a collective excitation of $q\bar{q}$ pairs in a system that obeys the modified Nambu--Jona-Lasinio Lagrangian is proposed. The rho emerges as a dormant Goldstone boson. The origin of the rho-meson mass is understood as a result of spontaneous chiral symmetry breaking. The low-energy dynamics of rho, pi, omega and gamma is consist

Yu-Qi Chen, Mark B. Wise

The observed $D^{**}$ mesons have $c\bar q$ flavor quantum numbers and spin-parity of the light degrees of freedom $s_\ell^{π_{\ell}} = 3/2^+$. In the $m_c \rightarrow \infty$ limit the spin of the charm quark is conserved and the $c \rightarrow D^{**}$ fragmentation process is characterized by the probability for the charm quark to fragment to a $D^{**}$ me

D. G. Lee, R. N. Mohapatra, M. K. Parida, M. Rani

We present our best estimates of the uncertainties due to heavy particle threshold corrections on the unification scale $M_U$, intermediate scale $M_I$ and coupling constant Alpha_U in the minimal non-supersymmetric SO(10) models. Using these , we update the predictions for proton life-time in these models.

K. J. Eskola, K. Kajantie, P. V. Ruuskanen

We compute in QCD perturbation theory the transverse energy carried by gluons, quarks and antiquarks with $p_T\ge p_0\approx 2$ GeV in Pb+Pb collisions at $\sqrt{s}=5500$ $A$GeV by using structure functions compatible with the small-$x$ increase observed at HERA. This gives a perturbative estimate for the energy and entropy density of the bulk system at time

V. Bernard, N. Kaiser, Ulf-G. Meißner

We consider the chiral expansion for the reaction $πN \to ππN$ in heavy baryon chiral perturbation theory. To order $M_π$ we derive novel low--energy theorems that compare favorably with recent determinations of the total cross sections for $π^+ p \to π^+ π^+ n$ and $π^- p \to π^0 π^0 n$.

W. Bernreuther, J. P. Ma, B. H. J. McKellar

At future $γγ$ colliders copious production of $t \bar{t}$ pairs is possible. This would allow a detailed investigation of the interactions involving the top quark. We propose some orrelations which are sensitive to $t \bar{t}$ final state interactions and we compute the QCD and standard model Higgs boson contributions to these correlations. QCD induced tran

H. Rieger, A. Schadschneider, M. Schreckenberg

We present numerical and analytical results for a special kind of one-dimensional probabilistic cellular automaton, the so called Domany-Kinzel automaton. It is shown that the phase boundary separating the active and the recently found chaotic phase exhibits reentrant behavior. Furthermore exact results for the $p_2$=0-line are discussed.

Chris M. Chambers, Ian G. Moss

We begin a program of work aimed at examining the interior of a rotating black hole with a non--zero cosmological constant. The generalisation of Teukolsky&#39;s equation for the radial mode functions is presented. It is shown that the energy fluxes of scalar, electromagnetic and gravity waves are regular at the Cauchy horizon whenever the surface gravity th

Ian G. Moss

Black hole solutions can be used to shed light on general issues in General Relativity and Quantum Physics. Black--hole hair, entropy and naked singularities are considered here, along with some implications for the inflationary universe scenario.

Kazuo Hida

The natural explanation of the excitation spectrum of the spin-1 antiferromagnetic Heisenberg chain is given from the viewpoint of the spin-1/2 ferromagnetic-antiferromagnetic alternating Heisenberg chain. The energy spectrum of the latter is calculated with fixed momentum $k$ by numerical diagonalization of finite size systems. It consists of a branch of pr

Neta A. Bahcall, Mirt Gramann, Renyue Cen

The distributions of peculiar velocities of rich clusters and of groups of galaxies are investigated for different cosmological models and are compared with observations. Four cosmological models are studied: standard ($Ω=1$) CDM, low-density CDM, HDM ($Ω=1$), and PBI. We find that rich clusters of galaxies exhibit a Maxwellian distribution of peculiar veloc

G. B. Rybicki, D. G. Hummer

Since the mass of the electron is very small relative to atomic masses, Thomson scattering of low-energy photons ($hν\ll m_ec^2$) produces thermal Doppler frequency shifts that are much larger than atomic Doppler widths. A method is developed here to evaluate the electron scattering emissivity from a given radiation field which is considerably faster than pr

A. L. Melott, T. Buchert, A. G. Weiß

We present results showing an improvement of the accuracy of perturbation theory as applied to cosmological structure formation for a useful range of scales. The Lagrangian theory of gravitational instability of Friedmann--Lema\^\i tre cosmogonies investigated and solved up to the third order in the series of papers by Buchert (1989, 1992, 1993), Buchert \&

Marco Aurelio Diaz

We study the light gluino scenario giving special attention to constraints from the masses of the light CP-even neutral Higgs $m_h$, the lightest chargino $m_{χ^{\pm}_1}$, and the second lightest neutralino $m_{χ^0_2}$, and from the $b\rightarrow sγ$ decay. We find that minimal $N=1$ supergravity, with a radiatively broken electroweak symmetry group and univ

Willy Fischler

We obtain new stronger bounds by orders of magnitude, on the ultimate temperature of the universe by exploiting the copious production of gravitinos at finite temperature.

F. L. Braghin, D. Vautherin

We investigate the response function of hot nuclear matter to a small isovector external field using a simplified Skyrme interaction reproducing the value of the symmetry energy coefficient. We consider values of the momentum transfer corresponding to the dipole oscillation in heavy nuclei. We find that while at zero temperature the particle hole interaction

J. Avan, E. Billey

We construct polynomial Poisson algebras of observables for the classical Euler-Calogero-Moser (ECM) models. The conserved Hamiltonians and symmetry algebras derived in a previous work are subsets of these algebras. We define their linear, $N \rightarrow \infty$ limits, realizing $\w_{\infty}$ type algebras coupled to current algebras.

S. Meljanac, M. Milekovic, S. Pallua

A general framework for the deformation of the single-mode oscillators is presented and all deformed single-mode oscillators are unified. The extensions of the Aric-Coon, genon, the para-Bose and the para-Fermi oscillators are proposed. The generalized harmonic oscillator considered by Brzezinski et al. is rederived in a simple way.Some remarks on deformatio

F. Delduc, L. Frappat, E. Ragoucy, P. Sorba

We perform an Hamiltonian reduction on a classical \cw(\cg, \ch) algebra, and prove that we get another \cw(\cg, \ch$&#39;$) algebra, with $\ch\subset\ch&#39;$. In the case $\cg=S\ell(n)$, the existence of a suitable gauge, called Generalized Horizontal Gauge, allows to relate in this way two \cw-algebras as soon as their corresponding \ch-algebras are relat

J. M. Deutsch, Hyoungsoo Yoon

The dynamics of a single chain tethered to an interface and in contact with a cross-linked network is examined numerically. When the network is put in contact with the tethered chain, the chain moves with dynamics that are highly constrained due to entanglements. When the surface is repulsive, the chain runs straight along the surface and then forms a plume

Vadim R. Kudashev

We consider the following hypothesis: some of KdV equation shock-like waves are invariant with respect to the combination of the Galilean symmetry and KdV equation higher symmetries. Also we demonstrate our approach on the example of Burgers equation.

Maxim Kontsevich, Simeon Vishik

Determinants of invertible pseudo-differential operators (PDOs) close to positive self-adjoint ones are defined throughthe zeta-function regularization. We define a multiplicative anomaly as the ratio $\det(AB)/(\det(A)\det(B))$ considered as a functionon pairs of elliptic PDOs. We obtained an explicit formula for the multiplicative anomaly in terms of symbo

S. N. Solodukhin

The 2D model of gravity with zweibeins $e^{a}$ and the Lorentz connection one-form $ω^{a}_{\ b}$ as independent gravitational variables coupled to 2d massless Dirac matter is considered. It is shown that the classical equations of motion are exactly integrated in the case of chiral fermions.

Tanya Khovanova

Tetramodule is a vector space supplied with the bimodule and bicomodule structures over a Hopf algebra. The exact definition is given. Some properties and applications to quantum groups are discussed.

V Z Enolskii, J C Eilbeck

We give an analytical description of the locus of the two-gap elliptic potentials associated with the corresponding flow of the Calogero--Moser system. We start with the description of Treibich--Verdier two--gap elliptic potentials. The explicit formulae for the covers, wave functions and Lamé polynomials are derived, together with a new Lax representation f

H. Awata, M. Fukuma, Y. Matsuo, S. Odake

We study quasifinite highest weight modules over the supersymmetric extension of the $W_{1+\infty}$ algebra on the basis of the analysis by Kac and Radul. We find that the quasifiniteness of the modules is again characterized by polynomials, and obtain the differential equations for highest weights. The spectral flow, free field realization over the $(B,C)$-

Sergei Khoroshkin, A. A. Stolin, V. N. Tolstoy

The general formula for the universal R-matrix for quantized nontwisted affine algebras by Khoroshkin and Tolstoy is applied for zero central charge highest weight modules of the quantized affine algebras. It is shown how the universal R-matrix produces the Gauss decomposition of trigonomitric R-matrix in tensor product of these modules. Explicit calculation

Sergei Khoroshkin, Valeriy N. Tolstoy

We show that some factors of the universal R-matrix generate a family of twistings for the standard Hopf structure of any quantized contragredient Lie (super)algebra of finite growth. As an application we prove that any two isomorphic superalgebras with different Cartan matrices have isomorphic q-deformations (as associative superalgebras) and their standard

Tomás Ortín

Under $SL(2,R)$ electric-magnetic duality transformations the Bogomolnyi bound of dilaton-axion black holes is known to be invariant. In this paper we show that this invariance corresponds to the covariance of the $N=4$ supersymmetry transformation rules and their parameters. In particular this implies that Killing spinors transform covariantly into Killing

Janaki Balakrishnan, Ian G. Moss

It is shown that improved potentials and corrected mass terms can be introduced by using a quadratic source term in the path integral construction for the effective action. The advantage of doing things this way is that we avoid ever having to deal with complex propagators in the loop expansion. The resulting effective action for electroweak phase transition

Daniel Ng, John N. Ng

We study the one-loop induced muon number processes when the standard model is minimally extended to include a $\rm SU(2)$ singlet of a charged scalar $h^+$ and a neutral fermion $N$. We find that $μ\rightarrow e γ$ is more sensitive for the former model whereas $μ-e$ conversion in nuclei for the latter. Effects of a scalar leptoquark $y^{1/3}$ and a heavy v

Ian G. Moss

The problem of calculating the effective potential for a real scalar field with a double--well potential is a possible preliminary to understanding symmetry breaking phase transitions in the early universe. It is argued here that it is necessary to include multiple saddle points in the path integral formalism and that quadratic source terms are important. Th

Tadashi Kon, Toshihiko Nonaka

We reexamine a possibility for the existence of a light supersymmetric partner of the top quark (stop) with mass 15$\sim$16GeV in the framework of the minimal supergravity GUT model (MSGUT). Such a stop could explain the slight excess of the high $p_{T}$ cross section of the $D^{*\pm}$-meson production in the two-photon process at TRISTAN. We find two types

C. Bourrely

The predictions of an impact-picture model for proton-antiproton elastic scattering are compared with the new UA4 experimental data in the Coulomb interference region at the center-of-mass energy of $541 GeV$. The predicted differential cross section, the parameter $ρ$ and the forward slope are in very good agreement with the data.

Leszek Roszkowski

A simple procedure is presented which leads to a dramatic simplification in the calculation of the relic density of stable particles in the Universe.

P. F. Gonzalez-Diaz

Special theory of relativity has been formulated in a vacuum momentum-energy representation which is equivalent to Einstein special relativity and predicts just the same results as it. Although in this sense such a formulation would be at least classically useless, its consistent extension to noninertial frames produces a momentum-energy metric which behaves

Lee Smolin

A cosmological scenario which explains the values of the parameters of the standard models of elementary particle physics and cosmology is discussed. In this scenario these parameters are set by a process analogous to natural selection which follows naturally from the assumption that the singularities in black holes are removed by quantum effects leading to

Lee Smolin

The canonical theory of quantum gravity in the loop representation can be extended to incorporate topology change, in the simple case that this refers to the creation or annihilation of &#34;minimalist wormholes&#34; in which two points of the spatial manifold are identified. Furthermore, if the states of the wormholes threaded by loop states are taken to be

I. S. Graham, E. Hernandez-Garcia, M. Grant

We study damage spreading in models of two-dimensional systems undergoing first order phase transitions. We consider several models from the same non-conserved order parameter universality class, and find unexpected differences between them. An exact solution of the Ohta-Jasnow-Kawasaki model yields the damage growth law $D \sim t^ϕ$, where $ϕ= t^{d/4}$ in $

Martin Janssen

The multifractal analysis of disorder induced localization-delocalization transitions is reviewed. Scaling properties of this transition are generic for multi parameter coherent systems which show broadly distributed observables at criticality. The multifractal analysis of local measures is extended to more general observables including scaling variables suc

S. R. Renn, B. W. Roberts

In this paper, we examine interwell tunneling between a pair of fractional quantum Hall liquids in a double quantum well system in a tilted magnetic field. Using a variational Monte Carlo method, we calculate moments of the intra-Landau level tunneling spectrum as a function of in-plane field component $B_{\parallel}$ and interwell spacing $d$. This is done

Frederic Mila

We study the properties of a quarter-filled system of electrons on a square lattice interacting through a local repulsion $U$ and a nearest-neighbour repulsion $V$ in the limit $V=+\infty$. We identify the ground-state for $U$ large enough and show that domain walls appear below a critical value $U_c=4t/π$. We argue that this corresponds to a metal-insulator

Martin D. Weinberg

The previous two companion papers demonstrate that slowly varying perturbations do not result in adiabatic cutoffs and provide a formalism for computing the long-term effects of time-dependent perturbations on stellar systems. Here, the theory is implemented in a Fokker-Planck code and a suite of runs illustrating the effects of shock heating on globular clu

Martin D. Weinberg

A new theory of gravitational shocking based on time-dependent perturbation theory shows that the changes in energy and angular momentum due to a slowly varying disturbance are not exponentially small for stellar dynamical systems in general. It predicts significant shock heating by slowly varying perturbations previously thought to be negligible according t

Martin D. Weinberg

The adiabatic criterion, widely used in astronomical dynamics, is based on the harmonic oscillator. It asserts that the change in action under a slowly varying perturbation is exponentially small. Recent mathematical results precisely define the conditions for invariance show that this model does not apply in general. In particular, a slowly varying perturba

Hyesung Kang, Jeremiah P. Ostriker, Renyue Cen, Dongsu Ryu

We present a detailed comparison of the simulation results of various cosmological hydrodynamic codes. Starting with identical initial conditions based on the Cold Dark Matter scenario for the growth of structure, we integrate from redshift $z=20$ to $z=0$ to determine the physical state within a representative volume of size $L^3$ where $L=64 h^{-1} {\rm Mp

Hyesung Kang, Renyue Cen, Jeremiah P. Ostriker, Dongsu Ryu

We exmaine the distribution of hot gas in a standard CDM model of the universe using high resolution hydrodynamic simulations. Adopting standard parameters determined from COBE and light element nucleosynthesis, $σ_8=1.05$, $Ω_b=0.06$ and assuming $h=0.5$, we find the X-ray emitting clusters, compute the luminosity function at several wavelengths, the temper

Renyue Cen, Jeremiah P. Ostriker

A new, three-dimensional, shock capturing, TVD hydrodynamic code is utilized to determine the distribution of hot gas in a CDM$+Λ$ model universe. This open model succeeds in matching local observations of clusters in contrast to the standard $Ω=1$, CDM model, which fails. It predicts an order of magnitude decline in the number density of bright ($hν= 2-10$k

Renyue Cen, Jeremiah P. Ostriker

We compute the evolution of spatially flat, mixed cold and hot dark matter (``MDM&#34;) models containing both baryonic matter and two kinds of dark matter. The mean final Zeldovich-Sunyaev $y$ parameter is estimated to be $\bar y=(5.4\pm 2.7)\times 10^{-7}$, with a rms fluctuation of approximately $\bar{δy}=(6.0\pm 3.0)\times 10^{-7}$ on arc minute scales.

Neta A. Bahcall, Renyue Cen

We show that the spatial correlation function of a flux-limited sample of X-ray selected clusters of galaxies will exhibit a correlation scale that is smaller than the correlation scale of a volume-limited, richness-limited sample of comparable apparent spatial density. The flux-limited sample contains clusters of different richnesses at different distances: