May 1993 arXiv papers — page 2

Ramzi R. Khuri

We derive an exact string-like soliton solution of D=10 heterotic string theory. The solution possesses $SU(2)\times SU(2)$ instanton structure in the eight-dimensional space transverse to the worldsheet of the soliton.

M. J. Duff, Ramzi R. Khuri

We present supersymmetric soliton solutions of the four-dimensional heterotic string corresponding to monopoles, strings and domain walls. These solutions admit the $D=10$ interpretation of a fivebrane wrapped around $5$, $4$ or $3$ of the $6$ toroidally compactified dimensions and are arguably exact to all orders in $α'$. The solitonic string solution e

Pankaj Jain, John P. Ralston

We review a new systematic data analysis procedure for color transparency experiments and its application to the proton nucleus scattering experiment. The method extracts the hard scattering rate as well as the survival probability for the protons travelling through the nucleus directly from the data. The method requires modelling of the nuclear attenuation

Pankaj Jain, John P. Ralston

We introduce a data analysis procedure for color transparency experiments which is considerably less model dependent than the transparency ratio method. The new method is based on fitting the shape of the A dependence of the nuclear cross section at fixed momentum transfer to determine the effective attenuation cross section for hadrons propagating through t

Hai-Yang Cheng

CP violation due to interference between $K_L$ and $K_S$ decays into $π^+π^-γ$ is analyzed in the Standard Model. The CP-violating parameter $ε'_{+- γ}$, which is the difference between $η_{+-γ}$ and $η_{+-}$, receives dominant contributions from $K^0-\bar{K}^0$ mixing and the gluon penguin diagram; its magnitude is calculated to be $10^{-2}ε$ at a typic

S. D. Bass

We emphasise the EMC spin effect as a problem of symmetry and discuss the renormalisation of the $C=+1$ axial tensor operators. This involves the generalisation of the Adler-Bell-Jackiw anomaly to each of these operators. We find that the contribution of the axial anomaly to the spin dependent structure function $g_1 (x, Q^2)$ scales at $O(α_s)$. This means

S. D. Bass, A. W. Thomas

We discuss the role of the U(1) axial anomaly in the spin structure functions of the nucleon, with particular emphasis on how one might determine its x dependence in present and future deep inelastic scattering experiments. We focus on the C-odd spin structure function g3 and also the deuteron structure function g1^d.

M. Nowakowski, A. Pilaftsis

We present an approach to bosonic ($Z^0, W^{\pm}$) as well as fermionic (top-quark) Breit-Wigner propagators which is consistent with gauge invariance arguments. In particular, for the $Z^0$-boson propagator we extend previous analyses and show that the part proportional to $k_μ k_ν/M^2$ must be modified near the resonance. We derive a mass shift which agree

Richard D. Ball, Stefano Forte, Jason Tigg

We propose a resolution of the puzzle posed by the discrepancy between the pion-nucleon sigma term inferred from pion-nucleon scattering, and that deduced from baryon mass splittings using the Zweig rule. We show that there is a significant hypercharge-dependent dynamical contribution to baryon masses, not hitherto included in the analysis, which may be esti

James E. Hetrick

$SU(N)$ gauge fields on a cylindrical spacetime are canonically quantized via two routes revealing almost equivalent but different quantizations. After removing all continuous gauge degrees of freedom, the canonical coordinate $A_μ$ (in the Cartan subalgebra $\h$) is quantized. The compact route, as in lattice gauge theory, quantizes the Wilson loop $W$, pro

H. -J. Matschull

It is shown that the Wheeler DeWitt constraint of canonical gravity coupled to Klein Gordon scalar fields and expressed in terms of Ashtekar's variables admits formal solutions which are parametrized by loops in the three dimensional hypersurface and which are extensions of the well known Wilson loop solutions found by Jacobson, Rovelli and Smolin.

Alexander Turbiner, Gerhard Post

Certain infinite families of operator identities related to powers of positive root generators of (super) Lie algebras of first-order differential operators and $q$-deformed algebras of first-order finite-difference operators are presented.

C. P. Price, D. Prichard

Previous efforts to find evidence of deterministic nonlinear dynamics in the global geomagnetic system have treated the geomagnetic system as autonomous. However, the geomagnetic system is strongly driven by the stochastic solar wind. We consider the response of the magnetosphere, as given by the AE index, for one day when the IMF had a nearly constant south

Giacomo Giampieri

It is believed that most quasars and galaxies present two common features: the presence in their core of a supermassive object, and the experience of one or more encounters with other galaxies. In this scenario, it is likely that a substantial fraction of active galactic nuclei harbour a supermassive binary, fueled by an accretion disk. These binaries would

Mirek Giersz, Rainer Spurzem

We compare the results for the dynamical evolution of star clusters derived from anisotropic gaseous models with the data from N-body simulations of isolated and one-component systems, each having modest number of stars. The statistical quality of N-body data was improved by averaging results from many N-body runs, each with the same initial parameters but w

J. N. Fry, Enrique Gaztanaga

To examine how peculiar velocities can affect the 2-, 3-, and 4-point redshift correlation functions, we evaluate volume-average correlations for configurations that emphasize and minimize redshift distortions for four different volume-limited samples from each of the CfA, SSRS, and IRAS redshift catalogs. We find a characteristic distortion for the 2-point

Claude LeBrun

Let (M,g) be an oriented Lorentzian 4-manifold, and consider the space S of oriented, unparameterized time-like 2-surfaces in M (string world-sheets) with fixed boundary conditions. Then the infinite-dimensional manifold S carries a natural complex structure and a compatible (positive-definite) Kaehler metric h on S determined by the Lorentz metric g. Simila

M. A. R. Osorio, M. A. Vazquez-Mozo

We study the cosmological solutions of the two-dimensional Brans-Dicke equations considering a gas of $c=1$ strings in $S^{1}\times \mbox{\bf R}$ as the source of the gravitational field. We also study the implications of the $R$-duality invariance on the solutions. To this purpose we conjecture that, as it happens for massless fields in finite boxes, the fr

M. A. R. Osorio, M. A. Vazquez-Mozo

We investigate the cosmological consequences of having quantum fields living in a space with compactified dimensions. We will show that the equation of state is not modified by topological effects and so the dynamics of the universe remains as it is in the infinite volume limit. On the contrary the thermal history of the universe depends on terms that are as

A. F. Heavens

This paper analyses the effects of random noise in determining errors and confidence levels for galaxy redshifts obtained by cross-correlation techniques. The main finding is that confidence levels have previously been overestimated, and errors inaccurately calculated in certain applications. New formulæ are presented.

Stephane Durand

We present a set of quantum-mechanical Hamiltonians which can be written as the $F^{\,\rm th}$ power of a conserved charge: $H=Q^F$ with $[H,Q]=0$ and $F=2,3,...\, .$ This new construction, which we call {\it fractional}\/ supersymmetric quantum mechanics, is realized in terms of \pg\ variables satisfying $\t^F=0$. Furthermore, in a pseudo-classical context,

Stephane Durand

Supersymmetric (pseudo-classical) mechanics has recently been generalized to {\it fractional}\/ supersymmetric mechanics. In such a construction, the action is invariant under fractional supersymmetry transformations, which are the $F^{\,\rm th}$ roots of time translations (with $F=1,2,...$). Associated with these symmetries, there are conserved charges with

A. H. Bougourzi, Robert A. Weston

We construct bosonized vertex operators (VOs) and conjugate vertex operators (CVOs) of $U_q(su(2)_k)$ for arbitrary level $k$ and representation $j\leq k/2$. Both are obtained directly as two solutions of the defining condition of vertex operators - namely that they intertwine $U_q(su(2)_k)$ modules. We construct the screening charge and present a formula fo

S. Chaudhuri, H. Itoyama, T. Ooshita

The one-plaquette Hamiltonian of large N lattice gauge theory offers a constructive model of a $1+1$-dimensional string theory with a stable ground state. The free energy is found to be equivalent to the partition function of a string where the world sheet is discretized by even polygons with signature and the link factor is given by a non-Gaussian propagato

E. Ramos, O. A. Soloviev

We use the formal Lie algebraic structure in the ``space'' of hamiltonians provided by equal time commutators to define a Kirillov-Konstant symplectic structure in the coadjoint orbits of the associated formal group. The dual is defined via the natural pairing between operators and states in a Hilbert space.

G. Moore

We study toroidal compactifications of string theories which include compactification of a timelike coordinate. Some new features in the theory of toroidal compactifications arise. Most notably, Narain moduli space does not exist as a manifold since the action of duality on background data is ergodic. For special compactifications certain infinite dimensiona

T. D. Palev, N. I. Stoilova

For generic $q$ we give expressions for the transformations of all essentially typical finite-dimensional modules of the Hopf superalgebra $U_q[gl(3/2)]$. The latter is a deformation of the universal enveloping algebra of the Lie superalgebra $gl(3/2)$. The basis within each module is similar to the Gel'fand-Zetlin basis for $gl(5)$. We write down expres

D. Altschuler, B. Davies

We construct level-0 modules of the quantum affine algebra $\Uq$, as the $q$-deformed version of the Lie algebra loop module construction. We give necessary and sufficient conditions for the modules to be irreducible. We construct the crystal base for some of these modules and find significant differences from the case of highest weight modules. We also cons

S. O. Warnaar, P. A. Pearce, K. A. Seaton, B. Nienhuis

The free energy and local height probabilities of the dilute A models with broken $\Integer_2$ symmetry are calculated analytically using inversion and corner transfer matrix methods. These models possess four critical branches. The first two branches provide new realisations of the unitary minimal series and the other two branches give a direct product of t

Vladimir O. Soloviev

The ordinary Poisson brackets in field theory do not fulfil the Jacobi identity if boundary values are not reasonably fixed by special boundary conditions. We show that these brackets can be modified by adding some surface terms to lift this restriction. The new brackets generalize a canonical bracket considered by Lewis, Marsden, Montgomery and Ratiu for th

A. Brandhuber, S. Emery, M. Langer, O. Piguet

The Green functions of the Chern-Simons theory quantized in the axial gauge are shown to be calculable as the unique, exact solution of the Ward identities which express the invariance of the theory under the topological supersymmetry of Delduc, Gieres and Sorella.

Subir Sachdev

The $N=\infty$ vector $O(N)$ model is a solvable, interacting field theory in three dimensions ($D$). In a recent paper with A. Chubukov and J. Ye~\cite{self}, we have computed a universal number, $\tilde{c}$, characterizing the size dependence of the free energy at the conformally-invariant critical point of this theory. The result~\cite{self} for $\tilde{c

Stephane Durand

Recently, we presented a new class of quantum-mechanical Hamiltonians which can be written as the $F^{th}$ power of a conserved charge: $H=Q^F$ with $F=2,3,...\,.$ This construction, called fractional supersymmetric quantum mechanics, was realized in terms of a paragrassmann variable $θ$ of order $F$, which satisfies $θ^F=0$. Here, we present an alternative

B. K. Jennings, G. A. Miller

New parameter free calculations including a variety of necessary kinematic and dynamic effects show that the results of BNL $(p,2p)$ measurements are consistent with the expectations of color transparency.

V. Barger, R. J. N. Phillips

We survey some recent ideas and progress in looking for particle physics beyond the Standard Model, connected by the theme of Supersymmetry (SUSY). We review the success of SUSY-GUT models, the expected experimental signatures and present limits on SUSY partner particles, and Higgs phenomenology in the minimal SUSY model.

Adam F. Falk, Michael Luke, Martin J. Savage, Mark B. Wise

We discuss the fragmentation of a heavy quark to a baryon containing two heavy quarks of mass $m_Q\ggΛ_{\rm QCD}$. In this limit the heavy quarks first combine perturbatively into a compact diquark with a radius small compared to $1/Λ_{\rm QCD}$, which interacts with the light hadronic degrees of freedom exactly as does a heavy antiquark. The subsequent evol

U. Baur, T. Han, J. Ohnemus

The process $p \pbar \rightarrow W^{\pm}γ+ X \rightarrow \ell^\pm νγ+ X$ is calculated to ${\cal O}(α_s)$ for general $CP$ conserving $WWγ$ couplings. At the Tevatron center of mass energy, the QCD corrections to $Wγ$ production are modest, and the Born and inclusive ${\cal O}(α_s)$ cross sections have similar sensitivities to the effects of anomalous coupli

Ina Sarcevic

We show that the recent measurements of the total photoproduction cross section at HERA energies [1] are in agreement with our earlier prediction based on high-energy hadronic structure of the photon in the QCD minijet-type model [2]. We discuss an improved calculation of the photoproduction cross section, in which the soft part, motivated by the Regge theor

P. Ramond

I present an algorithm in the search for symmetric textures in the quark Yukawa matrices. This is based on a talk at the Coral Gables conference in January 1993. I include the macro tables2.tex for making tables, and use the Santa Barbara jnl and reforder macros.

David Seckel

The thermal rates for converting neutrons to protons, and vice versa, are calculated, including corrections of order 1 MeV divided by a nucleon mass. The results imply that the primodial helium abundance predicted for big bang nucleosynthesis has been systematically underestimated by about $δY_4 = 0.0012$, i.e., $δY_4 / Y_4 \approx .005$.

A. Djouadi, M. Drees, H. König

We calculate supersymmetric QCD corrections (squark/gluino loops) to quark pair production in e+ e- annihilation, allowing for mixing between left- and right-handed squarks and taking into account the effects of nonzero quark masses. Corrections to the Z boson partial widths are generally small and positive, except in the case of large b-squark mixing, where

Robert M. Wald

The "problem of time" in canonical quantum gravity refers to the difficulties involved in defining a Hilbert space structure on states -- and local observables on this Hilbert space -- for a theory in which the spacetime metric is treated as a quantum field, so no classical metrical or causal structure is present on spacetime. We describe an approach -- much

Daniel Sudarsky, Robert M. Wald

We derive two new integral mass formulas for stationary black holes in Einstein-Yang-Mills theory. From these we derive a formula for $ \J \Omega -Q V $, from which it follows immediately that any stationary, nonrotating, uncharged black hole is static and has vanishing electric field on the static slices. In the Einstein-Maxwell case, we have, in addition,

Robert M. Wald

A simple proof of a strengthened form of the first law of black hole mechanics is presented. The proof is based directly upon the Hamiltonian formulation of general relativity, and it shows that the the first law variational formula holds for arbitrary nonsingular, asymptotically flat perturbations of a stationary, axisymmetric black hole, not merely for per

Piotr T. Chrusciel, Malcolm A. H. MacCallum, David B. Singleton

The structure of polyhomogeneous space-times (i.e., space-times with metrics which admit an expansion in terms of $r^{-j}\log^i r$) constructed by a Bondi--Sachs type method is analysed. The occurrence of some log terms in an asymptotic expansion of the metric is related to the non--vanishing of the Weyl tensor at Scri. Various quantities of interest, includ

B. R. Trees, D. L. Cox

Using an anisotropic hybridization matrix element, V($\vec k$), reflecting cubic symmetry at the ``rare-earth'' sites of the infinite U Anderson lattice, we calculate the bare quasiparticle scattering amplitude to order 1/N using slave Bosons and find significant differences with previous results under spherical symmetry. Due to exchange of density f

Satya N. Majumdar, Vladimir Privman

Two-particle annihilation reaction, A+A -> inert, for immobile reactants on the Bethe lattice is solved exactly for the initially random distribution. The process reaches an absorbing state in which no nearest-neighbor reactants are left. The approach of the concentration to the limiting value is exponential. The solution reproduces the known one-dimensional

Bracy H. Elton, Garry H. Rodrigue, C. David Levermore

Lattice Boltzmann methods are numerical schemes derived as a kinetic approximation of an underlying lattice gas. A numerical convergence theory for nonlinear convective-diffusive lattice Boltzmann methods is established. Convergence, consistency, and stability are defined through truncated Hilbert expansions. In this setting it is shown that consistency and

Douglas Scott, Mark Srednicki, Martin White

We discuss the effects of finite sky coverage and the uncertainty in extracting information about the power spectrum from experiments on small angular scales. In general the cosmic variance is enhanced by a factor of $4π/A$, where $A$ is the solid angle sampled by the experiment. As a rough guide, an experiment with sensitivity peaking at the $\ell$th multip

Vahid Karimipour

Quantum de Rham complexes on the quantum plane and the quantum group itself are constructed for the Zakrewski deformation of $ Fun ( SL(2)) $. As a by-product a new deformation of the two dimensional Heisenberg algeb ra is constructed which can be used to construct models of h-deformed quantum mechanics.

Jose F. Nieves, Palash B. Pal

Neutrinos can polarize a medium due to their weak interaction. This can manifest itself as an effective induced charge of the neutrino. We show how it is related to the Debye screening length in a plasma, first using the results of the 1-loop calculation of the neutrino electromagnetic vertex and then in general to all orders in $e$ and to leading order in t

L. Turban, B. Berche

The most general form of a marginal extended perturbation in a two-dimensional system is deduced from scaling considerations. It includes as particular cases extended perturbations decaying either from a surface, a line or a point for which exact results have been previously obtained. The first-order corrections to the local exponents, which are functions of

John Ellis, Marek Karliner

We re-analyze data on deep inelastic polarized lepton-nucleon scattering, with particular attention to testing the Bjorken sum rule and estimating the quark contributions to the nucleon spin. Since only structure function data at fixed $Q^2$ can be used to test sum rules, we use E142 asymmetry measurements and unpolarized structure function data to extract $

John Ellis N. E. Mavromatos, D. V. Nanopoulos

We exhibit string contributions to the $\nd{S}$ matrix relating in- and out- state density matrices that do not factorize as a product of $S$ and $S^\dagger$ matrices. They are associated with valley trajectories between topological defects on the string world sheet, that appear as quantum fluctuations in the space-time foam. Through their ultraviolet cut-of

Andreas Mielke, Hal Tasaki

Whether spin-independent Coulomb interaction can be the origin of a realistic ferromagnetism in an itinerant electron system has been an open problem for a long time. Here we study a class of Hubbard models on decorated lattices, which have a special property that the corresponding single-electron Schrödinger equation has $N_{\rm d}$-fold degenerate ground s

Vipul Periwal

The exact free energy of SU($N$) Chern-Simons theory at level $k$ is expanded in powers of $(N+k)^{-2}.$ This expansion keeps rank-level duality manifest, and simplifies as $k$ becomes large, keeping $N$ fixed (or vice versa)---this is the weak-coupling (strong-coupling) limit. With the standard normalization, the free energy on the three-sphere in this limi

D. A. Lowe, M. O'Loughlin

We examine the evaporation of two--dimensional black holes, the classical space--times of which are extended geometries, like for example the two--dimensional section of the extremal Reissner--Nordstrom black hole. We find that the evaporation in two particular models proceeds to a stable end--point. This should represent the generic behavior of a certain cl

Paul Fendley

This is intended to be a simple discussion of work done in collaboration with S. Cecotti, K. Intriligator and C. Vafa; and with H. Saleur. I discuss how $ Tr F (-1)^F e^{-βH}$ can be computed exactly in any N=2 supersymmetric theory in two dimensions. It gives exact information on the soliton spectrum of the theory, and corresponds to the partition function

Sidney Coleman, Shane Hughes

One of the paradoxes associated with the theory of the formation and subsequent Hawking evaporation of a black hole is the disappearance of conserved global charges. It has long been known that metric fluctuations at short distances (wormholes) violate global-charge conservation; if global charges are apparently conserved at ordinary energies, it is only bec

Demosthenes Ellinas

Coherent states path integral formalism for the simplest quantum algebras, q-oscillator, SU_q(2) and SU_q(1,1) is introduced. In the classical limit canonical structure is derived with modified symplectic and Riemannian metric. Non-constant deformation induced curvature for the phase spaces is obtained.

A. L. Kholodenko, V. V. Nesterenko

A new approach for investigating the classical dynamics of the relativistic string model with rigidity is proposed. It is based on the embedding of the string world surface into the space of a constant curvature. It is shown that the rigid string in flat space-time is described by the Euler-Lagrange equation for the Willmore functional in a space-time of the

George Thompson

In these lecture notes we explain a connection between Yang-Mills theory on arbitrary Riemann surfaces and two types of topological field theory, the so called $BF$ and cohomological theories. The quantum Yang-Mills theory is solved exactly using path integral techniques. Explicit expressions, in terms of group representation theory, are obtained for the par

J Ellis, N E Mavromatos, D V Nanopoulos

We show that, in string theory, as a result of the $W_{\infty}$-symmetries that preserve quantum coherence in the {\it full} string theory by coupling different mass levels, transitions between initial- and final-state density matrices for the effective light-particle theory involve non-Hamiltonian terms $\nd{δH}$ in their time evolution, and are described b

John C. Collins, Steve F. Heppelmann, Glenn A. Ladinsky

We show how the transverse polarization of a quark initiating a jet can be probed by the azimuthal distribution of two hadrons (of large $z$) in the jet. This permits a twist 2 asymmetry in hard processes when only one of the initial particles is polarized transversely. Applications to hadron-hadron and lepton-hadron scattering are discussed.

Ian I Kogan

We are discussing some aspects of the magnetic monopoles and cosmic strings interactions with axion domain walss and membranes. The monopole moving through an axion domain wall is transformed into a monopole bag - the state with a dyon quantum number, but smaller mass. In the case of an axion membrane the passing monopole excites the chiral charged state at

German Rodrigo, Arcadi Santamaria

The use of MS-like renormalization schemes in QCD requires an implementation of nontrivial matching conditions across thresholds, a fact often overlooked in the literature. We shortly review the use of these matching conditions in QCD and check explicitly that the prediction for $α_s(M_Z)$, obtained by running the strong coupling constant from the $M_τ$ scal

Z. Ligeti, Y. Nir, M. Neubert

We calculate, in the framework of QCD sum rules and to next-to-leading order in perturbation theory, the universal function $ξ_3(v\cdot v')$ which appears at order $1/m_Q$ in the heavy quark expansion of meson weak decay form factors. We find that radiative corrections of order $α_s$ are very important. Over the kinematic range accessible in semileptonic

Achilles D. Speliotopoulos

The asymptotic form of the energy density for a gas of particles surrounding a sphere of mass $M$ and radius $R$ is studied using Einstein's equations. It is shown that if the pressure of the gas $p$ varies linearly with the energy density $ρ$ for small $ρ$, then $ρ\sim 1/r^2$ for large $r$.

Achilles D. Speliotopoulos

The equations determining the energy density $ρ$ of a gas of photons in thermodynamic equilibrium with a spherical mass $M$ at a non-zero temperature $T_s>0$ is derived from Einstein's equations. It is found that for large $r$, $ρ\sim 1/r^2$ where the proportionality constant is a {\it fundamental constant\/} and is the same for all spherical masses at a

M. I. Polikarpov, Ken Yee, M. A. Zubkov

We derive different representations of compact QED fixed to Landau gauge by the lattice Faddeev-Popov procedure. Our analysis finds that (A)Nielsen-Olesen vortices arising from the compactness of the gauge-fixing action are {\it quenched\/}, that is, the Faddeev-Popov determinant cancels them out and they do not influence correlation functions such as the ph

S. Carlip

We do not yet know how to quantize gravity in 3+1 dimensions, but in lower dimensions we face the opposite problem: many of the approaches originally developed for (3+1)-dimensional gravity can be successfully implemented in 2+1 dimensions, but the resulting quantum theories are not all equivalent. In this talk, I discuss six such approaches --- reduced phas

G. W. Gibbons, Alan R. Steif

The Dirac equation is solved in the Einstein-Yang-Mills background found by Bartnik and McKinnon. We find a normalizable zero-energy fermion mode in the $s$-wave sector. As shown recently, their solution corresponds to a gravitational sphaleron which mediates transitions between topologically distinct vacua. Since the Bartnik-McKinnon solution is unstable, i

H. G. Evertz, M. Hasenbusch, M. Marcu, K. Pinn

We investigate the surface width $W$ of solid-on-solid surfaces in the vicinity of the roughening temperature $T_r$. Above $T_r$, $W^2$ is expected to diverge with the system size $L$ like $\ln L$. However, close to $T_r$ a clean $\ln{L}$ behavior can only be seen on extremely large lattices. Starting from the Kosterlitz-Thouless renormalization group, we de

J. Holm, R. Kree, K. Schönhammer

The Anderson impurity model for finite values of the Coulomb repulsion $U$ is studied using a slave boson representation for the empty and doubly occupied $f$-level. In order to avoid well known problems with a naive mean field theory for the boson fields, we use the coherent state path integral representation to first integrate out the double occupancy slav

Vincenzo Fiorentini, Michael Methfessel, Matthias Scheffler

The reconstruction mechanism of (001) fcc transition metal surfaces is investigated using a full-potential all-electron electronic structure method within density-functional theory. Total-energy supercell calculations confirm the experimental finding that a close-packed quasi-hexagonal overlayer reconstruction is possible for the late 5$d$-metals Ir, Pt, and

A. Yu. Boldin, A. A. Bronnikov, V. V. Dmitrieva, R. A. Sharipov

New additional equations for the Newtonian dynamical systems on Riemannian manifolds are found. They supplement the previously found weak normality conditions up to the complete normality conditions for Newtonian dynamical systems.

Eanna Flanagan

We analyze the sensitivity of a network of interferometer gravitational-wave detectors to the gravitational-wave stochastic background, and derive the dependence of this sensitivity on the orientations of the detector arms. We build on and extend the recent work of Christensen, but our conclusion for the optimal choice of orientations of a pair of detectors

John L. Friedman, Kristin Schleich, Donald M. Witt

All three-manifolds are known to occur as Cauchy surfaces of asymptotically flat vacuum spacetimes and of spacetimes with positive-energy sources. We prove here the conjecture that general relativity does not allow an observer to probe the topology of spacetime: any topological structure collapses too quickly to allow light to traverse it. More precisely, in

Ezer Melzer

We present a ``natural finitization'' of the fermionic q-series (certain generalizations of the Rogers-Ramanujan sums) which were recently conjectured to be equal to Virasoro characters of the unitary minimal conformal field theory (CFT) M(p,p+1). Within the quasi-particle interpretation of the fermionic q-series this finitization amounts to introduc

A. N. Leznov, A. V. Razumov

The properties of the canonical symmetry of the nonlinear Schrödinger equation are investigated. The densities of the local conservation laws for this system are shown to change under the action of the canonical symmetry by total space derivatives.

A. A. Starobinsky

If the Universe has the topology of a 3-torus ($T^3$), then it follows from recent data on large-scale temperature fluctuations $ΔT/T$ of the cosmic microwave background that either the minimal size of the torus is at least of the order of the present cosmological horizon, or the large-scale $ΔT/T$ pattern should have a symmetry plane (in case of the effecti

E. E. Donets, D. V. Gal'tsov

Static spherically symmetric asymptotically flat charged black hole solutions are constructed within the magnetic SU(3) sector of the 4-dimensional heterotic string effective action. They possess non-abelian hair in addition to the Coulomb magnetic field and are qualitatively similar to the Einstein-Yang-Mills colored SU(3) black holes except for the extrema

M. Trodden, V. Mukhanov, R. Brandenberger

We construct a model of gravity in 1+1 spacetime dimensions in which the solutions approach the Schwarzschild metric at large $r$ and de Sitter space far inside the horizon. Our model may be viewed as a two dimensional application of the `Limiting Curvature Construction' recently proposed by two of the authors.

O. Eboli, V. Ribelles

Focus of these lectures is the challenge of explaining the origin of structure in the Universe. The interplay between quantum field theory and classical general relativity has given rise to several interesting cosmological models which contain mechanisms for generating density inhomogeneities. The three theories discussed here are the inflationary Universe,

Timothy R. Bedding

Although delta Scorpii is a bright and well-studied star, the details of its multiplicity have remained unclear. Here we present the first diffraction-limited image of this 0.12 arcsec binary star, made using optical interferometry, and resolve the confusion that has existed in the literature over its multiplicity. Examining published speckle measurements, t

Alexander Kyatkin

We have shown an example of semiclassical transition in $ϕ^{4}$ theory with positive coupling constant. This process can be described by the classical $O(4)$-invariant solution, considered on a contour in the complex time plane. The transition is technically analogous to the one-instanton transition in the electroweak model. It is suppressed by the factor $\

Andre LeClair

We present a new application of affine Lie algebras to massive quantum field theory in 2 dimensions, by investigating the $q\to 1$ limit of the q-deformed affine $\hat{sl(2)}$ symmetry of the sine-Gordon theory, this limit occuring at the free fermion point. We describe how radial quantization leads to a quasi-chiral factorization of the space of fields. The

Antal Jevicki, Tamiaki Yoneya

The refrerences are corrected.

Oleg A. Soloviev

The interconnection between self-duality, conformal invariance and Lie-Poisson structure of the two dimensional non-abelian Thirring model is investigated in the framework of the hamiltonian method.

S. A. Abel, C. M. A. Scheich

Replaced with revised (uncorrupted) version We present a general scheme for generating (2,2) symmetric fermionic string models and classify the models in D=8 and D=6 space time dimensions. We discuss the relationship to other compactification schemes.

E. Bagan, P. Gosdzinsky

We show that the Heavy Quark Effective Theory is renormalizable perturbatively. We also show that there exist renormalization schemes in which the infinite quark mass limit of any QCD Green function is exactly given by the corresponding Green function of the Heavy Quark Effective Theory. All this is accomplished while preserving BRS invariance.

Masako Asano, Masayuki Tanimoto, Noriaki Yoshino

The canonical theory of $N=1$ supergravity is applied to Bianchi class A spatially homogeneous cosmologies. The full set of quantum constraints are then solved with the possible ordering ambiguity taken into account by introducing a free parameter. The wave functions are explicitly given for all the Bianchi class A models in a unified way. Some comments are

V. V. Dvoeglazov

The appearance of terms, which are analogous to ones required for symmetry breaking, in Lagrangian of Ref. [1] is shown to be caused by gauge invariance of quantum electrodynamics (QED) and by inaccuracy of the cited author in the choice of canonical variables. These terms do not have physical significance within modern quantum electrodynamics. PACS: 03.50.D

S. G. Naculich, H. A. Riggs, H. J. Schnitzer

We show that two-dimensional SO(N) and Sp(N) Yang-Mills theories without fermions can be interpreted as closed string theories. The terms in the 1/N expansion of the partition function on an orientable or nonorientable manifold M can be associated with maps from a string worldsheet onto M. These maps are unbranched and branched covers of M with an arbitrary

John Bechhoefer

This paper summarizes a talk presented at the April NATO ASI on Spatiotemporal Chaos in Complex Fluids, in Santa Fe, NM. The paper gives reasons that make complex fluids good material systems for conducting experiments on pattern formation and other nonequilibrium phenomena. Much of the discussion focuses on the different phenomena observed in solidification

L. A. Dickey

The totality of all Zakharov-Shabat equations (ZS), i.e., zero-curvature equations with rational dependence on a spectral parameter, if properly defined, can be considered as a hierarchy. The latter means a collection of commuting vector fields in the same phase space. Further properties of the hierarchy are discussed, such as additional symmetries, an analo

M. Cadoni, S. Mignemi

We discuss the low-energy effective string theory when moduli of the compactified manifold are present. Assuming a nontrivial coupling of the moduli to the Maxwell tensor, we find a class of regular black hole solutions. Both the thermodynamical and the geometrical structure of these solutions are discussed

Jose Gaite, Ram Brustein

We study the Batalin-Vilkovisky master equation for both open and closed string field theory with special attention to anomalies. Open string field theory is anomaly free once the minimal coupling to closed strings induced by loop amplitudes is considered. In closed string field theory the full-fledged master equation has to be solved order by order in pertu

G. Muenster

Talk given at the 6th Philosophy-and-Physics-Workshop ``Epistemological Aspects of the Role of Mathematics in Physical Science'', FEST, Heidelberg, Feb. 1993

C. J. Fewster

We re-examine the justification for the imposition of regular boundary conditions on the wavefunction at the Coulomb singularity in the treatment of the hydrogen atom in non-relativistic quantum mechanics. We show that the issue of the correct boundary conditions is not independent of the physical structure of the proton. Under the physically reasonable assu