June 1995 arXiv papers — page 8

Ph. Blanchard, A. Jadczyk

Event generating algorithm corresponding to a linear master equation of Lindblad's type is described and illustrated on two examples: that of a particle detector and of a fuzzy clock. Relation to other approaches to foundations of quantum theory and to description of quantum measurements is briefly discussed.

N. Fumita, H. Itoyama, T. Oota

We determine the motions of the roots of the Bethe ansatz equation for the ground state in the XXZ spin chain under a varying twist angle. This is done by analytic as well as numerical study at a finite size system. In the attractive critical regime $ 0< Δ<1 $, we reveal intriguing motions of strings due to the finite size corrections to the length of the st

H. C. Rosu

The &#34;circulatory wave&#34; (&#34;die zirkulierende Welle&#34;) put into evidence in 1949 by Wolter (Wolter&#39;s vortex) in total reflection is interpreted as a phase defect in the scalar theory of Green and Wolf of 1953, which is the Madelung (hydrodynamic) representation of the optical field. Some comments are added on its possible relevance for the Ha

Sam Gutmann

We consider the product of infinitely many copies of a spin-$1\over 2$ system. We construct projection operators on the corresponding nonseparable Hilbert space which measure whether the outcome of an infinite sequence of $σ^x$ measurements has any specified property. In many cases, product states are eigenstates of the projections, and therefore the result

Robert J. Finkelstein

We examine some issues that arise in the q-deformation of a gauge theory. If the deformation is carried out by replacing the equal time commutators of free fields by the corresponding q-commutators, the resulting propagators are not very much different from those of the undeformed theory as long as one is dealing with weak fields; but the theory still violat

Stavros Garoufalidis, Jerome Levine

This paper continues the study of finite-type invariants of homology spheres studied by Ohtsuki and Garoufalidis. We apply the surgery classification of links to give a diagrammatic description, using ideas of Ohtsuki. This uses a computation of the surgery equivalence classes of pure braids. We show that the order of any invariant, in Ohtsukis sense, is a m

Ronnie Lee, Weiping Li

In 1985 lectures at MSRI, A. Casson introduced an interesting integer valued invariant for any oriented integral homology 3-sphere Y via beautiful constructions on representation spaces (see [1] for an exposition). The Casson invariant λ(Y) is roughly defined by measuring the oriented number of irreducible representations of the fundamental group π_1(Y) in S

Akihiko Yukie

In this paper we consider an analogue of the zeta function for not necessarily prehomogeneous representations of GL(2) and compute some of the poles.

Akihiko Yukie

In this paper, we consider the most non-split parabolic D_4 type prehomogeneous vector space. The vector space is an analogue of the space of Hermitian forms. We determine the principal part of the zeta function.

Edward G. Dunne, Roger Zierau

If G is a (connected) complex Lie Group and Z is a generalized flag manifold for G, the the open orbits D of a (connected) real form G_0 of G form an interesting class of complex homogeneous spaces, which play an important role in the representation theory of G_0. We find that the group of automorphisms, i.e., the holomorphic diffeomorphisms, is a finite-dim

John D. Lorch, Lisa A. Mantini

An integral transform for G=U(1,q) is studied. The transform maps the positive spin ladder representations of G on a Bargmann-Segal-Fock space F_n^1,q into a space of polynomial-valued functions on the bounded realization B^q of G/K. An inversion is given for the transform and unitary structures are given for the geometric realization of the positive spin la

Daniel Cangemi, Gerald Dunne, Eric D'Hoker

We evaluate the exact ${\rm QED}_{2+1}$ effective energy for charged spin zero and spin half fields in the presence of a family of static magnetic field profiles localized in a strip of width $\lambda$. The exact result yields an infinite set of relations between the terms in the derivative expansion of the effective energy for a general magnetic field. Upon

K. Intriligator, N. Seiberg

We discuss the phases of four dimensional gauge theories and demonstrate them in solvable examples. Some of our simple examples exhibit confinement and oblique confinement. The theory has dual magnetic and dual dyonic descriptions in which these phenomena happen at weak coupling. Combined with the underlying electric theory, which gives a weak coupling descr

Valeri V. Dvoeglazov

The equations describing self/anti-self charge conjugate states, recently proposed by Ahluwalia, are re-written to covariant form. The corresponding Lagrangian for the neutral particle theory is proposed. From a group-theoretical viewpoint the construct is an example of the Nigam-Foldy-Bargmann-Wightman-Wigner-type quantum field theory based on the doubled r

Mu-In Park, Young-Jai Park

The theoretical foundation of the object moving faster than light in vacuum ({\it tachyon}) is still missing or incomplete. Here we present the classical foundation of the relativistic dynamics including the tachyon. An anomalous sign-factor extracted from the transformation of ${ \sqrt{1-u^{2}/c^{2} } }$ under the Lorentz transformation, which has been alwa

Fernando Quevedo

Duality between the `axion&#39; field $a$ and the antisymmetric tensor field $B_{μν}$ is traced after a nonperturbative effect, gaugino condensation, breaks the Peccei-Quinn symmetry $a \rightarrow a +c$. Even though the PQ symmetry was at its origin, duality is nevertheless {\it not} broken by this effect. Below condensation scale, the axion simply gets a m

Geoffrey Dixon

The structure of a previously developed representation of the Leech lattice, $Λ_{24}$, is exposed to further light with this unified and very simple construction.

David H. Adams, Siddhartha Sen

In topological field theories determinants of maps with negative as well as positive eigenvalues arise. We give a generalisation of the zeta-regularisation technique to derive expressions for the phase and scaling-dependence of these determinants. For theories on odd-dimensional manifolds a simple formula for the scaling dependence is obtained in terms of th

Dimitris Kominis

It is argued that the topcolor models recently proposed by Hill [1] may face significant constraints from flavor-changing neutral current processes (such as $B-\bar{B}$ mixing) unless the mixing angles between down-type quarks are small. The flavor-changing processes are mediated by scalar bound states which are likely to be light as a result of the near cri

F. Halzen

An ever-increasing body of evidence suggests that weakly interacting massive particles (WIMPs) constitute the bulk of the matter in the Universe. Experimental data, dimensional analysis and Standard Model particle physics are sufficient to evaluate and compare the performance of detectors searching for such particles either directly (e.g.\ by their scatterin

F. Hautmann

We report the results of including resummed splitting functions in the QCD evolution equations at small x, and discuss the predictions that follow for the deep inelastic structure functions. *Contribution at XXX Rencontres de Moriond, Les Arcs, March 1995

Elena Papageorgiu

Assuming that a horizontal abelian (gauge) symmetry is at the origin of texture zeros in the fermion mass matrices we show how realistic mass patterns can be generated in the presence of scalar fields whose vacuum expectation value breaks the extra $U(1)$ symmetry. In the simplest scenario with just one pair of singlet fields and under the assumption of L-R

James M. Cline

I summarize recent results (work done in collaboration with Kimmo Kainulainen and Axel Vischer) in which we make quantitative predictions for the baryon asymmetry of the universe in the charge transport mechanism of electroweak baryogenesis. Making favorable assumptions about the unknown quantities relevant to the problem, we find that the mechanism is margi

Xuemin Jin

Within the QCD sum-rule approach in an external field, we calculate the baryon matrix element of isovector-scalar current, $H_{\rm B}=\langle B|\overline{u}u- \overline{d}d|B\rangle/2M_{\rm B}$, for octet baryons, which appears in the response of the correlator of baryon interpolating fields to a constant isovector-scalar external field. The sum rules are ob

Wolfgang J. Mantke

The conventions that Wu and Yang assumed for the kaon phases in the context of $CP$ symmetrical two-pion decay channels fix the relative kaon phase. This fact, apparently not emphasized sufficiently in the past, has recently been overlooked by Hayakawa and Sanda. In particular, Wu and Yang fix the relative phase to a different value than the one resulting fr

Ralf Hempfling

We study the effects of additional fields on the unification of gauge couplings in supersymmetric models. We find that the effects are quite constrained by the requirement of SU(5) gauge invariance. In general, we find that any extension of the MSSM will form complete SU(5) multiplets or spoil gauge coupling unification.

S. L. Cheng, C. Q. Geng, W. -T. Ni

We reexamine the axion-photon couplings in various invisible axion models motivated by the recent proposal of using optical interferometry at the ASST facility in the SSCL to search for axion. We illustrate that the assignment of $U(1)_{PQ}$ charges for the fermion fields plays an important role in determining the couplings. Several simple non-minimal invisi

Yuhsuke Yoshida

I investigate the bound state problems of lowest-lying mesons and heavy mesons. Chiral symmetry is essential when one consider lowest-lying mesons. Heavy quark symmetry plays an central role in considering the semi-leptonic form factors of heavy mesons. Various properties based on the symmetries are revealed using Bethe-Salpeter equations.

G. Palma, J. C. Rojas

Assuming triviality of the 4-dimensional $λϕ^4$-theory we compute the effective potential by means of a self consistent Feynman-Bogoliubov method. This potential $U_{eff}^{FB}$ depends on a UV-cutoff, which is fixed by a stability condition for the gap-equation for the plasma mass. It shows a second order phase transition at zero temperature, in agreement wi

Naomichi Hatano, Yoshihiro Nishiyama

The $S=1/2$ antiferromagnetic Heisenberg model on multi-leg ladders is investigated. Criticality of the ground-state transition is explored by means of finite-size scaling. The ladders with an even number of legs and those with an odd number of legs are distinguished clearly. In the former, the energy gap opens up as $ΔE\sim{J_\perp}$, where ${J_\perp}$ is t

Sanjoy K. Sarker

Motivated by recent discovery of colossal magnetoresistance in La$_(1-x)$Ca$x$MnO$_3$ and other manganites, we have studied the double exchange model. We argue that the forced alignment of conduction-electron spin with the core spins that causes ferromagnetism also projects out a large part of the Hilbert space needed for coherent propagation of electrons ca

Satya N. Majumdar, Anirvan M. Sengupta

We study the non-equilibrium dynamics (purely dissipative and relaxational) in a semi-infinite system following a quench from the high temperature disordered phase to its critical temperature. We show that the local autocorrelation near the surface of a semi-infinite system decays algebraically in time with a new exponent which is different from the bulk. We

Giorgio Parisi, Marc Potters

In this letter, we show that the formulae of Bray and Moore for the average logarithm of the number of metastable states in spin glasses can be obtained by calculating the partition function with $m$ coupled replicas with the symmetry among these explicitly broken according to a generalization of the `two-group&#39; ansatz. This equivalence allows us to find

Agha Afsar Ali

We study a nonconservative sandpile model in one dimension, in which, if the height at any site exceeds a threshold value, the site topples by transferring one particle along each bond connecting it to its neighbours. Its height is then set to one, irrespective of the initial value. The model shows nontrivial critical behavior. We solve this model analytical

Erick J. Guerra, Ruth A. Daly

Powerful extended radio galaxies like Cygnus A can be used for cosmological tests. The characteristic, time-independent length $D_*$ for several radio sources is calculated and compared to the average physical length for a sample of radio galaxies. The ratio of these two lengths as a function of redshift is used to constrain cosmological parameters. Cygnus A

D. C. Ellison, M. G. Baring, F. C. Jones

The rate at which particles are accelerated by the first-order Fermi mechanism in shocks depends on the angle, \teq{\Tbone}, that the upstream magnetic field makes with the shock normal. The greater the obliquity the greater the rate, and in quasi-perpendicular shocks rates can be hundreds of times higher than those seen in parallel shocks. In many circumsta

S. J. McNally, J. A. Peacock

We present constraints on decaying-particle models in which an enhanced relativistic density allows an $Ω=1$ Cold Dark Matter universe to be reconciled with acceptable values for the Hubble constant. Such models may contain extra small-scale power, which can have important consequences for enhanced object formation at high redshifts. Small-scale galaxy clust

Daniel J. Eisenstein, Abraham Loeb

We use Monte Carlo realizations of halo formation histories and a spherical accretion model to calculate the expected scatter in the velocity dispersions of galactic halos of a given mass due to differences in their formation times. Assuming that the rotational velocity of a spiral galaxy is determined by the velocity dispersion of its halo and that its lumi

Neil Trentham

\noindent The galaxy IRAS F10214+4724, discovered in a spectroscopic survey of a 0.2 Jy sample by Rowan-Robinson and collaborators in 1991, is significantly more luminous than any other known galaxy. Its bolometric luminosity is comparable to those of the most luminous quasars. Recent obsservations have revealed a candidate foreground group of galaxies, whic

Edmund Bertschinger

COSMICS is a package of fortran programs useful for computing transfer functions and microwave background anisotropy for cosmological models, and for generating gaussian random initial conditions for nonlinear structure formation simulations of such models. Four programs are provided: {\bf linger\_con} and {\bf linger\_syn} integrate the linearized equations

John H. Schwarz

This paper is a sequel to one in which we examined the affine symmetry algebras of arbitrary classical principal chiral models and symmetric space models in two dimensions. It examines the extension of those results in the presence of gravity. The main result is that even though the symmetry transformations of the fields depend on the gravitational backgroun

A. Ceresole, M. Billo&#39;, R. D&#39;Auria, S. Ferrara

The generalisation of the rigid special geometry of the vector multiplet quantum moduli space to the case of supergravity is discussed through the notion of a dynamical Calabi--Yau threefold. Duality symmetries of this manifold are connected with the analogous dualities associated with the dynamical Riemann surface of the rigid theory. N=2 rigid gauge theori

Nathan Seiberg

Recently the vacuum structure of a large class of four dimensional (supersymmetric) quantum field theories was determined exactly. These theories exhibit a wide range of interesting new physical phenomena. One of the main new insights is the role of ``electric-magnetic duality.&#39;&#39; In its simplest form it describes the long distance behavior of some st

C. M. Yung, M. T. Batchelor

We study the $O(n)$ loop model on the honeycomb lattice with open boundary conditions. Reflection matrices for the underlying Izergin-Korepin $R$-matrix lead to three inequivalent sets of integrable boundary weights. One set, which has previously been considered, gives rise to the ordinary surface transition. The other two sets correspond respectively to the

John M. Cornwall, Duncan A. Morris

We study idealizations of the full nonlinear Schwinger-Dyson equations for the asymptotically free theory of $ϕ^3$ in six dimensions in its meta-stable vacuum. We begin with the cubic nonlinearity and go on to all-order nonlinearities which contain instanton effects. We show how our toy models of the cubic Schwinger-Dyson equations contain the usual diseases

R. Harlander, M. Jezabek, J. H. Kuehn

Top quark production in $p\bar p$ and $e^+e^-$ collisions is enhanced by the exchange of a Higgs boson. The enhancement factors are calculated in the threshold region using the Greens function method.

J. Kalinowski, M. Krawczyk

Large fermion mass effect on the Yukawa process $Z \ra b\bar{b}\ra b\bar{b} h (A)$ in the entire range of the neutral Higgs boson masses is found. It is particularly important for light Higgs bosons, which are still not excluded experimentally in a general two-Higgs-doublet model.

S. Ying

We explore a consistent way to extend the partially conserved axial vector current (PCAC) relation and corresponding current algebra results. The paper includes investigations of a chiral Ward-Takahashi identity, the explicit chiral symmetry breaking by a finite current quark mass, the modifica- tion of the PCAC relation and its consequences. Two explicit re

Elliott Lieb, Michael Loss, Jan Philip Solovej

In the presence of arbitrarily large magnetic fields, matter composed of electrons and nuclei was known to be unstable if $α$ or $Z$ is too large. Here we prove that matter {\it is stable\/} if $α<0.06$ and $Zα^2<0.04$.

Chung-Pei Ma, Edmund Bertschinger

This paper presents a systematic treatment of the linear theory of scalar gravitational perturbations in the synchronous gauge and the conformal Newtonian (or longitudinal) gauge. It differs from others in the literature in that we give, in both gauges, a complete discussion of all particle species that are relevant to any flat cold dark matter (CDM), hot da

J. L. Hewett

Rare $B$ decays provide an opportunity to probe for new physics beyond the Standard Model. In this paper, we propose to measure the tau polarization in the inclusive decay $B\to X_sτ^+τ^-$ and discuss how it can be used, in conjunction with other observables, to completely determine the parameters of the flavor-changing low-energy effective Hamiltonian. Both

L. V. Verozub

A new method of gravitational- waves detection in the $10^{-2}÷10^{-1} Hz$ band for a space laboratory is proposed based on the use of the Kozorez effect in the magnetic interaction of superconducting solenoids.

C. Hamzaoui, Z. Z. Xing

The effect of inelastic final-state interactions (IFSI&#39;s) on the determination of the weak phase $α$ from the isospin triangles of $B\rightarrow ππ$ is qualitatively illustrated. Neglecting the electroweak penguins and IFSI&#39;s and assuming the dominance of the top-quark loop in strong penguin diagrams, we propose an experimentally accessible way to ap

J. G. Russo, A. A. Tseytlin

An exact conformal model representing a constant magnetic field background in heterotic string theory is explicitly solved in terms of free creation/annihilation operators. The spectrum of physical states is examined for different possible embeddings of the magnetic U(1) subgroup. We find that an arbitrarily small magnetic field gives rise to an infinite num

M. Bleicher, C. Spieles, A. Jahns, R. Mattiello

In the framework of the relativistic quantum molecular dynamics approach ({\small RQMD}) we investigate antideuteron ($\overline{d}$) observables in Au+Au collisions at 10.7~AGeV. The impact parameter dependence of the formation ratios $\overline{d}/\overline{p}^2$ and ${d}/{p}^2$ is calculated. In central collisions, the antideuteron formation ratio is pred

Miyuki KATSUKI, Shin&#39;ichi NOJIRI, Akio SUGAMOTO

In the framework of the two-form gravity, which is classically equivalent to the Einstein gravity, the one-loop effective potential for the conformal factor of metric is calculated in the finite volume and in the finite temperature by choosing a temporal gauge condition. There appears a quartically divergent term which cannot be removed by the renormalizatio

Miyuki KATSUKI, Hiroto KUBOTANI, Shin&#39;ichi NOJIRI, Akio SUGAMOTO

A mechanism of generating the metric is proposed, where the Kalb-Ramond symmetry existing in the topological BF theory is broken through the condensation of the string fields which are so introduced as to couple with the anti-symmetric tensor fields $B$, invariantly under the Kalb-Ramond symmetry. In the chiral decomposition of the local Lorentz group, the n

Albert Schwarz

We study a topological sigma-model ($A$-model) in the case when the target space is an ($m_0|m_1$)-dimensional supermanifold. We prove under certain conditions that such a model is equivalent to an $A$-model having an ($m_0-m_1$)-dimensional manifold as a target space. We use this result to prove that in the case when the target space of $A$-model is a compl

John K. Elwood, Mark B. Wise, Martin J. Savage, James W. Walden

Using chiral perturbation theory we calculate the imaginary parts of the $K_L \rightarrow π^+ π^- e^+ e^-$ form factors that arise from $ππ\rightarrow π^+ π^-$ and $ππ\rightarrow π^+ π^- γ^*$ rescattering. We discuss their influence on CP violating variables in $K_L \rightarrow π^+ π^- e^+ e^-$.

Tao Han

We review the phenomenological aspects of the exact and approximate Radiation Amplitude Zeros (RAZ) and discuss the prospects of searches for these zeros at current and future collider experiments.

S. V. Kravchenko, Whitney Mason, J. E. Furneaux, V. M. Pudalov

We study the behavior of the extended states of a two-dimensional electron system in silicon in a magnetic field, B. Our results show that the extended states, corresponding to the centers of different Landau levels, merge with the lowest extended state as B --> 0. Using our data, we construct an experimental-based ``disorder vs filling factor&#39;&#39; phas

Vladimir N. Kostur, Jayanta K. Bhattacharjee, Richard A. Ferrell

The longitudinal ultrasonic attenuation at low temperatures for a $d$-wave superconducting order parameter is examined. The ratio of the superconducting to normal state attenuation, $α_{s}/α_{n}$, depends strongly on the direction of propagation of ultrasound with maxima corresponding to nodes of the order parameter on the Fermi surface. We propose that meas

Michael White

Until recently, punctuation has received very little attention in the linguistics and computational linguistics literature. Since the publication of Nunberg&#39;s (1990) monograph on the topic, however, punctuation has seen its stock begin to rise: spurred in part by Nunberg&#39;s ground-breaking work, a number of valuable inquiries have been subsequently un

Vasileios Hatzivassiloglou, Kevin Knight

We present an approach to syntax-based machine translation that combines unification-style interpretation with statistical processing. This approach enables us to translate any Japanese newspaper article into English, with quality far better than a word-for-word translation. Novel ideas include the use of feature structures to encode word lattices and the us

Kevin Knight, Vasileios Hatzivassiloglou

Large-scale natural language generation requires the integration of vast amounts of knowledge: lexical, grammatical, and conceptual. A robust generator must be able to operate well even when pieces of knowledge are missing. It must also be robust against incomplete or inaccurate inputs. To attack these problems, we have built a hybrid generator, in which gap

Kevin Knight, Ishwar Chander, Matthew Haines, Vasileios Hatzivassiloglou

Knowledge-based machine translation (KBMT) techniques yield high quality in domains with detailed semantic models, limited vocabulary, and controlled input grammar. Scaling up along these dimensions means acquiring large knowledge resources. It also means behaving reasonably when definitive knowledge is not yet available. This paper describes how we can fill

Rodrigo Ibata, G. Gilmore, M. J. Irwin

We have discovered a new Galactic satellite galaxy in the constellation of Sagittarius. The Sagittarius dwarf galaxy is the nearest galaxy known, subtends an angle of $> 10$ degrees on the sky, lies at a distance of $24 \kpc$ from the Sun, $\sim 16 \kpc$ from the centre of the Milky Way. Itis comparable in size and luminosity to the largest dwarf spheroidal,

S. Skorik, A. Kapustin

We study boundary bound states using the Bethe ansatz formalism for the finite $XXZ$ $(Δ>1)$ chain in a boundary magnetic field $h$. Boundary bound states are represented by the ``boundary strings&#39;&#39; similar to those described in the work of H.Saleur, S.Skorik. We find that for certain values of $h$ the ground state wave function contains boundary str

James M. Cline, Kimmo Kainulainen, Axel P. Vischer

We quantitatively study the charge transport mechanism of electroweak baryogenesis in a realistic two-Higgs-doublet model, comparing the contributions from quarks and leptons reflecting from electroweak domain walls, and comparing the exact profile of the CP-violating phase with a commonly used ansatz. We note that the phenomenon of spontaneous CP violation

I. A. Dynnikov, A. P. Veselov

Examples of Morse functions with integrable gradient flows on some classical Riemannian manifolds are considered. In particular, we show that a generic height function on the symmetric embeddings of classical Lie groups and certain symmetric spaces is a perfect Morse function, i.e. has as many critical points as the homology requires, and the corresponding g

M. Finkelberg, V. Schechtman

This article is a sequel to hep-th/9411050, q-alg/9412017, q-alg/9503013. Given a collection of $m$ finite factorizable sheaves $\{\CX_k\}$, we construct here some perverse sheaves over configuration spaces of points on a projective line $\BP^1$ with $m$ additional marked points. We announce here (with sketch proof) the computation of the cohomology spaces o

G. G. Ross, S. Sarkar

We reconsider the problems of cosmological inflation in effective supergravity theories. A singlet field in a hidden sector is demonstrated to yield an acceptable inflationary potential, without fine tuning. In the simplest such model, the requirement of generating the microwave background anisotropy measured by COBE fixes the inflationary scale to be about

Robert H. Heffner, Michael R. Norman

A brief review is given on the current state of experimental and theoretical work in the field of heavy fermion superconductivity. Particular emphasis is placed on those experiments which demonstrate the presence of an unconventional order parameter, as well as the intricate interplay of magnetism and superconductivity in these metals. On the theoretical fro

John Ellis, Dmitri Kharzeev, Aram Kotzinian

We point out that measurements of longitudinal $Λ$ polarization in the target fragmentation region of deep--inelastic $ν\,N$ and $μ\,N$ or $e \, N$ scattering may test dynamical mechanisms invoked to explain the proton spin puzzle. A previously-proposed model for polarized $\bar s s$ pairs in the proton wave function reproduces successfully the negative $Λ$

C. Spieles, M. Bleicher, A. Jahns, R. Mattiello

In the framework of RQMD we investigate antiproton observables in massive heavy ion collisions at AGS energies and compare to preliminary results of the E878 collaboration. We focus here on the considerable influence of the *real* part of an antinucleon--nucleus optical potential on the antiproton momentum spectra.

D. Comelli, M. Pietroni, A. Riotto

Motivated by cosmological applications like electroweak baryogenesis, we develop a field theoretic approach to the computation of particle currents on a space-time dependent and CP-violating Higgs background. We consider the Standard Model model with two Higgs doublets and CP violation in the scalar sector, and compute both fermionic and Higgs currents by me

R. Martini, G. F. Post, P. H. M. Kersten

Differential calculi of Poincare-Birkhoff-Witt type on universal enveloping algebras of Lie algebras g are defined. This definition turns out to be independent of the basis chosen in g. The role of automorphisms of g is explained. It is proved that no differential calculus of Poincare-Birkhoff-Witt type exists on semi-simple Lie algebras. Examples are given,

H. F. Chau, H. -K. Lo

One-way functions are used in modern cryto-systems as doortraps because their inverse functions are supposed to be difficult to compute. Nonetheless with the discovery of reversible computation, it seems that one may break a one-way function by running a reversible computer backward. Here, we argue that reversible computation alone poses no threat to the exi

M. J. Duff, Sergio Ferrara, Ramzi R. Khuri, Joachim Rahmfeld

We present new classes of string-like soliton solutions in ($N=1$; $D=10$), ($N=2$; $D=6$) and ($N=4$; $D=4$) heterotic string theory. Connections are made between the solution-generating subgroup of the $T$-duality group of the compactification and the number of spacetime supersymmetries broken. Analogous solutions are also noted in ($N=1,2$; $D=4$) compact

J. D. Finley, III, John K. McIver

We are looking for the universal covering algebra for all symmetries of a given pde, using the sine-Gordon equation as a typical example for a non-evolution equation. For non-evolution equations, Estabrook-Wahlquist prolongation structures for non-local symmetries depend on the choice of a specific sub-ideal, of the contact module, to define the pde. For eac

H. Saller, R. Breuninger, M. Haft

A structural explanation of the coupling constants in the standard model, i.e the fine structure constant and the Weinberg angle, and of the gauge fixing contributions is given in terms of symmetries and representation theory. The coupling constants are normalizations of Lorentz invariantly embedded little groups (spin and polarization) arising in a harmonic

M. Alvarez, J. M. F. Labastida

Vassiliev invariants up to order six for arbitrary torus knots $\{ n , m \}$, with $n$ and $m$ coprime integers, are computed. These invariants are polynomials in $n$ and $m$ whose degree coincide with their order. Furthermore, they turn out to be integer-valued in a normalization previously proposed by the authors.

Rajesh Parwani

In the first part, the induced vacuum spin around an Aharonov-Bohm flux string in massless three-dimensional QED is computed explicitly and the result is shown to agree with a general index theorem. A previous observation in the literature, that the presence of induced vacuum quantum numbers which are not periodic in the flux make an integral-flux AB string

A. M. Grundland, P. Winternitz, W. J. Zakrzewski

We use the methods of group theory to reduce the equations of motion of the $CP^{1}$ model in (2+1) dimensions to sets of two coupled ordinary differential equations. We decouple and solve many of these equations in terms of elementary functions, elliptic functions and Painlev{é} transcendents. Some of the reduced equations do not have the Painlev{é} propert

Finn Larsen, Frank Wilczek

The quantum corrections to black hole entropy, variously defined, suffer quadratic divergences reminiscent of the ones found in the renormalization of the gravitational coupling constant (Newton constant). We consider the suggestion, due to Susskind and Uglum, that these divergences are proportional, and attempt to clarify its precise meaning. Using a Euclid

Ramzi R. Khuri

In this review I discuss various aspects of some of the recently constructed black hole and soliton solutions in string theory. I begin with the axionic instanton and related solutions of bosonic and heterotic string theory. The latter ten-dimensional solutions can be compactified to supersymmetric monopole, string and domain wall solutions which break $1/2$

N. P. Warner

Quantum integrable models that possess $N=2$ supersymmetry are investigated on the half-space. Conformal perturbation theory is used to identify some $N=2$ supersymmetric boundary integrable models, and the effective boundary Landau-Ginzburg formulations are constructed. It is found that $N=2$ supersymmetry largely determines the boundary action in terms of

Miao Li

By studying the pure Yang-Mills theory on a circle, as well as an adjoint scalar coupled to the gauge field on a circle, we propose a quenching prescription in which the combination of the spatial component of the gauge field and $P$ is treated as a dynamic variable. Averaging over momentum is not necessary, therefore the usual ultraviolet cut-off is elimina

Charles Nash, Denjoe O&#39;Connor

We analyze a continuous spin Gaussian model on a toroidal triangular lattice with periods $L_0$ and $L_1$ where the spins carry a representation of the fundamental group of the torus labeled by phases $u_0$ and $u_1$. We find the {\it exact finite size and lattice corrections}, to the partition function $Z$, for arbitrary mass $m$ and phases $u_i$. Summing $

E. Elizalde, S. D. Odintsov

The coupling, in a non-standard way, of a bosonic string theory with a dilaton and antisymmetric fields is investigated. By integrating over the antisymmetric fields, a Coulomb-like interaction term is generated. The static potential of a theory of this kind is obtained from the corresponding non-local zeta function, in some approximation. An interpretation

Cihan Saclioglu

The Weierstrassian $\wp, ζ$ and $σ$ functions are generalized to ${\bf R}^{n}$. The $n=3$ and $n=4$ cases have already been used in gravitational and Yang-Mills instanton solutions which may be interpreted as explicit realizations of spacetime foam and the monopole condensate, respectively. The new functions satisfy higher dimensional versions of the periodi

C. Chiou-Lahanas, G. A. Diamandis, B. C. Georgalas, X. N. Maintas

We quantize the tachyon field in a static two dimensional dilaton gravity black hole background,and we calculate the Hawking radiation rate. We find that the thermal radiation flux, due to the tachyon field, is larger than the conformal matter one. We also find that massive scalar fields which do not couple to the dilaton, do not give any contribution to the

Kenichiro Aoki, Tomoyasu Ichihara

We analyze the properties of mesons in 1+1 dimensional QCD with bosonic and fermionic ``quarks&#39;&#39; in the large $\nc$ limit. We study the spectrum in detail and show that it is impossible to obtain massless mesons including boson constituents in this model. We quantitatively show how the QCD mass inequality is realized in two dimensional QCD. We find t

James M. Cline, Kimmo Kainulainen

We study the effect of Debye screening of hypercharge when a net fermion number is reflected from a domain wall during a first order phase transition, which may be relevant for electroweak baryogenesis. We give a simple method for computing the effect of screening within the diffusion approximation, whose results are compatible with those of a more elaborate

T. Schaefer, E. V. Shuryak

We study mesonic and baryonic correlation functions in the temporal directions in the vicinity of the critical temperature $T\simeq T_c$ using the instanton liquid model. In this model chiral symmetry restoration is driven by the formation of instanton-antiinstanton molecules. Although we find the signals for all hadronic poles to be drastically reduced, som

N. N. Nikolaev, B. G. Zakharov, V. R. Zoller

In color dipole gBFKL dynamics, we describe the emerging gBFKL phenomenology of a subasymptotic energy dependence of the diffraction slope and discuss possibilities of testing the gBFKL predictions in exclusive photo- and electroproduction of vector mesons $V$ at HERA. A substantial shrinkage of the diffraction cone $γ^{*}p\rightarrow Vp$ processes from the

Gerhard A. Schuler

We discuss a dispersion relation in the photon mass and show how (in principle) model-independent constraints on the parton distribution functions of the photon, notably a momentum sumrule, can be obtained. We present two sets of parametrizations, SaS~1 and~2, corresponding to two rather extreme realizations of the non-perturbative part. Inclusive electron s

M. Majewski

On the basis of the relation between values of the coupling constants determined from data fit it is concluded that the dominating constituent of the $Θ$ meson is the glueball. The possibility that $Θ$ meson decays into two $σ(750)$ mesons is suggested.

N. J. Watson

The question of the definition of effective charges for non-abelian gauge theories is discussed, focusing in particular on both the pinch technique and background field method approaches. It is argued that there does exist a unique generalization of the QED concept of an effective charge to non-abelian theories, and that this generalization is given by the p

Akira Takamura, Shoji Sawada, Yoshimitsu Matsui, Shinsaku Kitakado

We calculate the $F/D$ ratios of spin-nonflip baryon vertex for an arbitrary number of color degrees of freedom $N_c$ both in the non-relativistic quark model with the $SU(6)$ spin-flavor symmetry and in the chiral soliton model with $SU(3)$ flavor symmetry. We find that the spin-nonflip $F/D$ ratio tends to $-1$ in the limit of $N_c \to \infty$. We show tha