April 1994 arXiv papers — page 2

Andrea Dal Corso, Francesco Mauri

We present a method to compute high-order derivatives of the total energy which can be used in the framework of density functional theory. We provide a proof of the $2n+1$ theorem for a general class of energy functionals in which the orbitals are not constrained to be orthonormal. Furthermore, by combining this result with a recently introduced Wannier-like

G. J. Chaitin

This is a shortened version of "The Limits of Mathematics--Course Outline & Software" (IBM Research Report RC 19324, December 1993) in which all Mathematica code has either been deleted or, if absolutely necessary, replaced by C code. The intention is to make this material available to a wider audience.

James E. Lidsey

The possibility that the form of the inflationary potential can be reconstructed from a knowledge of the primordial power spectra of scalar (density) and tensor (gravity wave) perturbations is discussed and reviewed. It is suggested that measurements of the scalar spectral index and the amplitude of the tensor spectrum at one scale should be possible in the

Eduardo Cattani, Alicia Dickenstein, Bernd Sturmfels

Given n polynomials in n variables with a finite number of complex roots, for any of their roots there is a local residue operator assigning a complex number to any polynomial. This is an algebraic, but generally not rational, function of the coefficients. On the other hand, the global residue, which is the sum of the local residues over all roots, depends r

John D. Stack, Steven D. Neiman, Roy J. Wensley

The axis for Figure 2 was wrong. It has been fixed and the postscript file replaced (The file was called comp.ps).

Peter Goetsch, Robert Graham

While the linearity of the Schrödinger equation and the superposition principle are fundamental to quantum mechanics, so are the backaction of measurements and the resulting nonlinearity. It is remarkable, therefore, that the wave-equation of systems in continuous interaction with some reservoir, which may be a measuring device, can be cast into a linear for

E. Langmann, G. W. Semenoff

We use the Hamiltonian framework to study massless QCD$_{1+1}$, i.e.\ Yang-Mills gauge theories with massless Dirac fermions on a cylinder (= (1+1) dimensional spacetime $S^1\times \R$) and make explicite the full, non-perturbative structure of these quantum field theory models. We consider $N_F$ fermion flavors and gauge group either $\U(N_C)$, $\SU(N_C)$ o

B. Grammaticos, A. Ramani, J. Hietarinta

We introduce multilinear operators, that generalize Hirota's bilinear $D$ operator, based on the principle of gauge invariance of the $τ$ functions. We show that these operators can be constructed systematically using the bilinear $D$'s as building blocks. We concentrate in particular on the trilinear case and study the possible integrability of equa

Jaroslaw Kwapisz

We construct a diffeomorphism of the two-dimensional torus which is isotopic to the identity and whose rotation set is not a polygon.

Erik Koelink

From Koornwinder's interpretation of big $q$-Legendre polynomials as spherical elements on the quantum $SU(2)$ group an addition formula is derived for the big $q$-Legendre polynomial. The formula involves Al-Salam--Carlitz polynomials, little $q$-Jacobi polynomials and dual $q$-Krawtchouk polynomials. For the little $q$-ultraspherical polynomials a prod

Lee Mosher

The quotient of a biautomatic group by a subgroup of the center is shown to be biautomatic. The main tool used is the Neumann-Shapiro triangulation of $S^{n-1}$, associated to a biautomatic structure on ${\Bbb Z}^n$. As an application, direct factors of biautomatic groups are shown to be biautomatic.

Alexander Vilenkin, Serge Winitzki

We introduce a model detector which registers the passage of a particle through the detector location, without substantially perturbing the particle wave function. (The exact time of passage is not determined in such measurements.) We then show that our detector can operate in a classically forbidden region and register particles passing through a certain po

Nathan Berkovits

After adding a scalar chiral boson to the usual superspace variables, the four-dimensional Green-Schwarz superstring is quantized in a manifestly SO(3,1) super-Poincaré covariant manner. The constraints are all first-class and form an N=2 superconformal algebra with $c=-3$. Since the Calabi-Yau degrees of freedom are described by an N=2 superconformal field

Irina Jakushina

A formal uniform asymptotic solution of the system of differential equations $ h^{2}\frac{d^{2}U_{1}}{dz^{2}}+Φ_{1} U_{1}=αU_{2} $ , $ h^{2}\frac{d^{2}U_{2}}{dz^{2}}+Φ_{2} U_{2}=αU_{1}$ , for $ z\in D$ and for h real, large is obtained, when D contains curve-crossing point. Asymptotic approximations for the solutions are constructed in terms of parabolic cyl

Paul Demkin

The model which generalizes Ponzano and Regge $3D$ and Carfora-Martellini-Marzuoli $4D$ euclidean quantum gravity is considered. The euclidean Einstein-Regge action for a $D$-simplex is given in the semiclassical limit by a gaussian integral of a suitable $3nj$-symbol.

J. Bernabéu, S. M. Bilenky, F. J. Botella, J. Segura

The contribution of a neutrino magnetic moment $μ_ν$ to the cross section of the process $νe^{-}\rightarrow νe^{-} γ$ has been calculated and compared with the Standard Electroweak one. The radiative process allows to reach low enough values of $Q^2$ without the need to operate at very small energies of recoil electrons. Regions in the phase space which are

I. F. Albuquerque

We have searched for the rare hyperon radiative decay Omega- to Xi- gamma, using the Fermilab Proton Center 375 GeV/c charged hyperon beam. Our measurement of the Omega- beam fraction at 13.6 m from production is (4.8 +_ 0.4)10**(-5). No signal was found and we determine a new upper limit of (4.6 x 10**-4) at 90% CL for the Omega- to Xi- gamma branching rati

Eduard Massó, Ramon Toldrà

We use the constraints arising from primordial nucleosynthesis to bound the strength $F$ of non-standard neutrino-neutrino interactions, when the right-handed neutrinos participate in the interaction. We find $F < 3 \times 10^{-3}\ G_F$, which is five orders of magnitude more stringent than the limit obtained using LEP data. We also show that secret interact

A. Ballestrero, E. Maina, S. Moretti

The complete matrix element for $e^+e^-\ar W^+W^-\bar b b$ is computed at tree level and applied to: {\bf a)} $\bar t t$ production and decay ; {\bf b)} $ZH$ production followed by $Z\ar \bar bb$ and $H\ar WW$. In both cases we include finite width effects and all irreducible backgrounds.

H. Shiomi, T. Hatsuda

Effective masses of $ρ$ and $ω$ mesons in nuclear medium are studied in a hadronic effective theory. Both the pole position and the screening mass decrease in nuclear matter due to the polarization of the nucleon Dirac sea. The physical origin of the decrease is a reduction of the wave function renormalization constant induced by the tensor (vector) interact

J. Samuel, R. Nityananda

We draw attention to an elementary flaw in a recently proposed experiment to measure the wave function of a single quantum system.

James E. Lidsey

The quantum cosmology of the string effective action is considered within the context of the Bianchi class A minisuperspace. An exact unified solution is found for all Bianchi types and interpreted physically as a quantum wormhole. The solution is generalized for types ${\rm VI_0}$ and ${\rm VII_0}$. The Bianchi type IX wavefunction becomes increasingly loca

Gregory A. Burnett

The closed-universe recollapse conjecture is studied for a class of closed spherically symmetric spacetimes which includes those having as a matter source: (1) a massless scalar field; (2) a perfect fluid obeying the equation of state $ρ= P$; and (3) null dust. It is proven that all timelike curves in any such spacetime must have length less than $6 \max_Σ(2

D. V. Fursaev, G. Miele

In the framework of finite temperature conformal scalar field theory on de Sitter space-time the linearized Einstein equations for the renormalized stress tensor are exactly solved. In this theory quantum field fluctuations are concentrated near two spheres of the de Sitter radius, propagating as light wave fronts. Related cosmological aspects are shortly di

Viqar Husain

Two non-static solutions for three dimensional gravity coupled to matter fields are given. One describes the collapse of radiation that results in a black hole. This is the three dimensional analog of the Vaidya metric, and is used to construct a model for mass inflation. The other describes plane gravitational waves for coupling to a massless scalar field.

N. Elstner, A. P. Young

For the spin-$\frac{1}{2}$ Heisenberg antiferromagnet on the Kagomé lattice we calculate the high temperature series for the specific heat and the structure factor. A comparison of the series with exact diagonalisation studies shows that the specific heat has further structure at lower temperature in addition to a high temperature peak at $T\approx 2/3$. At

Daniel Braun, Gilles Montambaux

We have studied numerically several statistical properties of the spectra of disordered electronic systems under the influence of an Aharonov Bohm flux $φ$, which acts as a time--reversal symmetry breaking parameter. The distribution of curvatures of the single electron energy levels has a modified Lorentz form with different exponents in the GOE and GUE reg

A. V. Postnikov, T. Neumann, G. Borstel

The frequencies of transverse-optical $Γ$ phonons in KNbO$_3$ and KTaO$_3$ are calculated in the frozen-phonon scheme making use of the full-potential linearized muffin-tin orbital method. The calculated frequencies in the cubic phase of KNbO$_3$ and in the tetragonal ferroelectric phase are in good agreement with experimental data. For KTaO$_3$, the effect

H. Rieger B. Steckemetz, M. Schreckenberg

Interrupted aging in the two-dimensional Ising spin glass model with Gaussian couplings is established and investigated via extensive Monte-Carlo simulations. The spin autocorrelation function scales with $t/τ(t_w)$, where $t_w$ is the waiting time and $τ$ is equal to $t_w$ for waiting times smaller than the equilibration time $τ_{\rm eq}$. The spatial corre

R. J. Radtke, M. R. Norman

Recent angle-resolved photoemission (ARPES) experiments have indicated that the electronic dispersion in some of the cuprates possesses an extended saddle point near the Fermi level which gives rise to a density of states that diverges like a power law instead of the weaker logarithmic divergence usually considered. We investigate whether this strong singula

H. J. Bussemaker, M. H. Ernst, J. W. Dufty

In this paper, for the first time a theory is formulated that predicts velocity and spatial correlations between occupation numbers that occur in lattice gas automata violating semi-detailed balance. Starting from a coupled BBGKY hierarchy for the $n$-particle distribution functions, cluster expansion techniques are used to derive approximate kinetic equatio

Stuart M. Shieber, Yves Schabes, Fernando C. N. Pereira

We present a system for generating parsers based directly on the metaphor of parsing as deduction. Parsing algorithms can be represented directly as deduction systems, and a single deduction engine can interpret such deduction systems so as to implement the corresponding parser. The method generalizes easily to parsers for augmented phrase structure formalis

Raymond E. White, C. S. R. Day, Isamu Hatsukade, John P. Hughes

We analyze the Ginga LAC and Einstein SSS spectra of four cooling flow clusters, A496, A1795, A2142 and A2199, each of which shows firm evidence of a relatively cool component. The inclusion of such cool spectral components in joint fits of SSS and LAC data leads to somewhat higher global temperatures than are derived from the high energy LAC data alone. We

Buell T. Jannuzi, Richard Elston, Gary D. Schmidt, Paul S. Smith

Optical spectropolarimetry of the luminous IRAS source FSC10214$+$4724 (z$=2.286$) reveals that the strong (\twid17\%) linear polarization detected by Lawrence \etal\/ is shared by both the narrow UV emission lines and the underlying continuum. This observation and the brightness of the source rule out synchrotron emission and dichroic extinction by dust as

Christian Elphick, Aric Hagberg, Ehud Meron

This is a study of front dynamics in reaction diffusion systems near Nonequilibrium Ising-Bloch bifurcations. We find that the relation between front velocity and perturbative factors, such as external fields and curvature, is typically multivalued. This unusual form allows small perturbations to induce dynamic transitions between counter-propagating fronts

Brian D. Serot, Huabin Tang

Two-loop corrections with scalar and vector form factors are calculated for nuclear matter in the Walecka model. The on-shell form factors are derived from vertex corrections within the framework of the model and are highly damped at large spacelike momenta. The two-loop corrections are evaluated first by using the one-loop parameters and mean fields and the

Manuel Gonzalez, Joaquin M. Gutierrez

We prove that weakly unconditionally Cauchy (w.u.C.) series and unconditionally converging (u.c.) series are preserved under the action of polynomials or holomorphic functions on Banach spaces, with natural restrictions in the latter case. Thus it is natural to introduce the unconditionally converging polynomials, defined as polynomials taking w.u.C. series

Manuel Gonzalez, Joaquin M. Gutierrez

Letting $E$, $F$ be Banach spaces, the main two results of this paper are the following: (1) If every (linear bounded) operator $E\rightarrow F$ is unconditionally converging, then every polynomial from $E$ to $F$ is unconditionally converging (definition as in the linear case). (2) If $E$ has the Dunford-Pettis property and every operator $E\rightarrow F$ i

Manuel Gonzalez, Joaquin M. Gutierrez

A Banach space $E$ has the Grothendieck property if every (linear bounded) operator from $E$ into $c_0$ is weakly compact. It is proved that, for an integer $k>1$, every $k$-homogeneous polynomial from $E$ into $c_0$ is weakly compact if and only if the space ${\cal P}(^kE)$ of scalar valued polynomials on $E$ is reflexive. This is equivalent to the symmetri

R. Kirschner

The contribution to the perturbative Regge asymptotics of the exchange of two reggeized fermions with opposite helicity is investigated. The methods of conformal symmetry known for the case of gluon exchange are extended to this case where double-logarithmic contributions dominate the asymptotics. The Regge trajectories at large momentum transfer are calcula

Katrin Becker

The SL(2,R)/U(1) gauged Wess-Zumino-Witten model is an exact conformal field theory describing a black hole in two-dimensional space-time. The free field approach of Bershadsky and Kutasov is a suitable formulation of this CFT in order to compute physically interesting quantities of this black hole. We find the space-time interpretation of this model for k=9

R. D. Ball, R. S. Thorne

We consider decoupling in the context of an effective quantum field theory of two scalar fields with well separated mass scales and a $Z_2\times Z_2$ symmetry. We first prove, using Wilson&#39;s exact renormalization group equation, that the theory is renormalizable, in the same way that we showed in a previous paper that theories with a single mass scale we

R. D. Ball, R. S. Thorne

We consider the infrared and ultraviolet behaviour of the effective quantum field theory of a single $Z_2$ symmetric scalar field. In a previous paper we proved to all orders in perturbation theory the renormalizability of massive effective scalar field theory using Wilson&#39;s exact renormalization group equation. Here we show that away from exceptional mo

L. P. Horwitz

A soluble model for the relativistically description of an unstable system is given in terms of relativistic quantum field theory, with a structure similar to Van Hove&#39;s generalization of the Lee model in the non-relativistic theory.

D. V. Volkov

This paper is part of the lecture given at the TH Division of CERN and devoted to the CXXV anniversary of the birthday of Elie Cartan (1869-1951). It is shown how the methods of differential geometry, due to E. Cartan, were applied to the construction of the supersymmetry transformation law and to the actions for Goldstone fermions and supergravity.

Changrim Ahn, Kong-Ju-Bock Lee, Soonkeon Nam

We use thermodynamic Bethe ansatz to study nonrelativistic scattering theory of low energy excitations of 1D Hubbard model, using the $S$-matrices proposed by E\ss ler and Korepin. This model can be described by two types of excitation states, holons and spinons, as asymptotic states. In the attractive regime, the spinon is massive while the holon is massles

Joao M. Soares

Direct CP violation can occur in B-meson decays of the type b -> d+c+cbar, where the charm-anticharm pair forms a J/psi. The CP asymmetry requires the contribution to the amplitude from decays into other states, which rescatter into d+J/psi via final state interactions. In particular, states with the same quark content as d+J/psi can contribute. A perturbati

V. Barger, J. F. Beacom, Kingman Cheung, T. Han

We present calculations of cross sections for single $W^-$ and $Z$ production and $W^-W^-, W^-Z, W^-γ, ZZ$, and $W^+W^-$ pair production within the Standard Model at $e^-e^-$ linear colliders. We evaluate Standard-Model Higgs boson production in the channels $e^-e^- \to e^-e^- H$, $e^-νW^- H$, and $e^-e^- ZH$. We also illustrate the enhancements in the $W^-W

G. Dvali, Q. Shafi

Within a supersymmetric unified framework we explore the resolution of the gauge hierarchy problem taking account of the non-renormalizable terms in the superpotential. For $[SU(3)]^3$ supplemented by a discrete R parity, we find the remarkable property that the vacuum configuration corresponding to the correct gauge symmetry breaking remains flat (in the su

P. Gambino, A. Sirlin

We present strong indirect evidence for the contribution of bosonic electroweak corrections in the Standard Model. Although important conceptually, these corrections give subleading contributions in current high energy experiments, and it was previously thought that they are difficult to detect. We also discuss the separate contribution of the Higgs boson.

V. N. Gribov

The behaviour of the light quark vacuum in the presence of a heavy quark is investigated.

L. -E. Adam, K. G. Chetyrkin

We compute the renormalization mismatch displayed in 1--loop approximation by classically equivalent 4-quark operators and coming from different possible definitions of the $γ_5$ matrix in dimensional regularization. The result is then employed to study the effect of the various treatments of $γ_5$ upon the size of radiative corrections to 4-quark condensate

A. Frommer, V. Hannemann, Th. Lippert, B. Noeckel

The stabilized biconjugate gradient algorithm BiCGStab recently presented by van der Vorst is applied to the inversion of the lattice fermion operator in the Wilson formulation of lattice Quantum Chromodynamics. Its computational efficiency is tested in a comparative study against the conjugate gradient and minimal residual methods. Both for quenched gauge c

Dmitri Vassilevich

We study vector fields on a disk satisfying two types of mixed boundary conditions. These boundary conditions are selected by BRST-invariance in electrodynamics. They also appear in the de Rham complex. The manifest construction of the harmonic expansion is presented. The eigenfunctions of the vector Laplace operator are expressed in terms of fields satisfyi

M. S. Delgaty, R. B. Mann

Macroscopic traversable wormhole solutions to Einstein&#39;s field equations in $(2+1)$ and $(3+1)$ dimensions with a cosmological constant are investigated. Ensuring traversability severely constrains the material used to generate the wormhole&#39;s spacetime curvature. Although the presence of a cosmological constant modifies to some extent the type of mat

R. B. Mann

Black hole spacetimes can arise when a Liouville field is coupled to two- dimensional gravity. Exact solutions are obtained both classically and when quantum corrections due to back reaction effects are included. The black hole temperature depends upon the mass and the thermodynamic limit breaks down before evaporation of the black hole is complete, indicati

Henk van Elst, James E Lidsey, Reza Tavakol

In this paper the quantum cosmological consequences of introducing a term cubic in the Ricci curvature scalar $R$ into the Einstein--Hilbert action are investigated. It is argued that this term represents a more generic perturbation to the action than the quadratic correction usually considered. A qualitative argument suggests that there exists a region of p

Gregory B. Cook

The construction of initial-data sets representing binary black-hole configurations in quasi-circular orbits is studied in the context of the conformal-imaging formalism. An effective-potential approach for locating quasi-circular orbits is outlined for the general case of two holes of arbitrary size and with arbitrary spins. Such orbits are explicitly deter

Suzhou Huang, Bernd Schreiber

To study the manifestation of the Aharonov-Bohm effect in many-body systems we consider the statistical mechanics of the Gross-Neveu model on a ring (1+1 dimensions) and on a cylinder (2+1 dimensions) with a thin solenoid coinciding with the axis. For such systems with a non-trivial magnetic flux ($θ$) many thermodynamical observables, such as the order para

G. T. Barkema, M. E. J. Newman, M. Breeman

It is experimentally observed that adsorbate atoms and vacancies on (111) surfaces of fcc metals cluster into islands which are approximately hexagonal, but which on closer inspection turn out to have equilibrium facets which alternate in length $ABABAB$ around the six sides of the island. By contrast, previous theoretical models for island faceting predict

Alain Comtet, Alexander Moroz, Stéphane Ouvry

Predictions of Akkermans et al. are essentially changed when the Krein spectral displacement operator is regularized by means of zeta function. Instead of piecewise constant persistent current of free electrons on the plane one has a current which varies linearly with the flux and is antisymmetric with regard to all time preserving values of $α$ including $1

A. M. Zagoskin, S. N. Rashkeev, R. I. Shekhter, G. Wendin

The breakdown of conductance quantization in a quantum point contact in the presence of random long-range impurity potential is discussed. It is shown that in the linear response regime a decisive role is played by the indirect backscattering mechanism via quasilocalized states at the Fermi level; this can provide much higher backscattering rate than any dir

P. G. McQueen, D. W. Hess, J. W. Serene

We present self-consistent calculations for the self-energy and magnetic susceptibility of the 2D and 3D symmetric Anderson lattice Hamiltonian, in the fluctuation exchange approximation. At high temperatures, strong f-electron scattering leads to broad quasiparticle spectral functions, a reduced quasiparticle band gap, and a metallic density of states. As t

Helio J. Rocha-Pinto, Lilia I. Arany-Prado, Walter J. Maciel

A model is presented for the chemical evolution of the solar neighbourhood which takes into account three families of galactic objects, according to their condensation states: stars, refuses and gas. Stars are defined as every condensed objects with masses greater than or equal to the minimum mass which ignites hydrogen and which will give rise to an evoluti

D. Syer

A test mass, $M$, moving through an ambient medium of light particles with lower average kinetic energy than itself suffers a deceleration caused by its scattering of the light particles. The phenomenon is usually referred to as dynamical friction. The velocity, $\v$, of the test mass decays on a timescale independent of $\v$ in the non-relativistic case. We

Dong Lai

Tidal interaction in a coalescing neutron star binary can resonantly excite the g-mode oscillations of the neutron star when the frequency of the tidal driving force equals the intrinsic g-mode frequencies. We study the g-mode oscillations of cold neutron stars using recent microscopic nuclear equations of state, where we determine self-consistently the soun

K. Van Riper, B. Link, R. Epstein

Differential rotation between the neutron star crust and a more rapidly rotating interior superfluid leads to frictional heating that affects the star&#39;s long-term thermal evolution and resulting surface emission. Here we present the results of thermal evolution simulations based on two models of the vortex pinning forces that bracket a range of plausible

B. Grzadkowski

A helicity asymmetry for top quarks originating from Higgs boson decays is investigated within the 2-Higgs Doublet Model. The asymmetry is sensitive to CP violation in the scalar sector of the model, whereas it vanishes in the Standard Model. It has been checked that without any fine tuning of parameters the asymmetry can reach $50\%$. Standard decay pattern

Cenalo Vaz, Louis Witten

Positive energy singularities induced by Sine-Gordon solitons in 1+1 dimensional dilaton gravity with positive and negative cosmological constant are considered. When the cosmological constant is positive, the singularities combine a white hole, a timelike singularity and a black hole joined smoothly near the soliton center. When the cosmological constant is

O. Ganor, J. Sonnenschein, S. Yankielowicz

We study maps from a 2D world-sheet to a 2D target space which include folds. The geometry of folds is discussed and a metric on the space of folded maps is written down. We show that the latter is not invariant under area preserving diffeomorphisms of the target space. The contribution to the partition function of maps associated with a given fold configura

P. S. Aspinwall, D. R. Morrison

The moduli space of N=(4,4) string theories with a K3 target space is determined, establishing in particular that the discrete symmetry group is the full integral orthogonal group of an even unimodular lattice of signature (4,20). The method combines an analysis of the classical theory of K3 moduli spaces with mirror symmetry. A description of the moduli spa

Xavier Vilasis-Cardona

Irreversibility of RG flows in two dimensions is shown using conserved vector currents. Out of a conserved vector current, a quantity decreasing along the RG flow is built up such that it is stationary at fixed points where it coincides with the constant coefficient of the two current correlation function. For Wess-Zumino-Novikov-Witten models this constant

Guillermo A. Mena Marugan

We show that if the space of physical states spanned by the wormhole wave functions can be equipped with a Hilbert structure, such a Hilbert space must coincide with that of the Lorentzian gravitational system under consideration. The physical inner product can then be determined by imposing a set of Lorentzian reality conditions. The Hilbert space of the gr

D. Polarski, A. A. Starobinsky

Dynamics of long-wave isocurvature perturbations during an inflationary stage in multiple (multi-component) inflationary models is calculated analytically for the case where scalar fields producing this stage interact between themselves through gravity only. This enables to determine correct amplitudes of such perturbations produced by vacuum quantum fluctua

L. Ciotti, S. N. Dutta

We investigate two possible effects of the tidal field induced by a spherical cluster on its elliptical galaxy members: the modification of the ellipticity of a spherical galaxy and the isophotal alignment in the cluster radial direction of a misaligned prolate galaxy. Numerical N-body simulations have been performed for radial and circular galactic orbits.

Naoya Hata

The present status of the solar neutrino problem is reviewed. The strongest motivation for new neutrino physics comes from the complete phenomenological failure of astrophysical solutions: (1) The standard solar model is excluded by each of the solar neutrino experiments. (2) The combined results of Homestake and Kamiokande are incompatible with any astrophy

Jose&#39; P. S. Lemos

A black hole solution of Einstein&#39;s field equations with cylindrical symmetry is found. Using the Hamiltonian formulation one is able to define mass and angular momentum for the cylindrical black hole through the corresponding and equivalent three dimensional theory. The causal structure is analyzed. Comments: revised version.

F. Lizzi

We argue that the Virasoro algebra for the closed bosonic string can be cast in a form which is suitable for the limit of vanishing string tension. In this form the limit of the Virasoro algebra gives the null string algebra. The anomalous central extension is seen to vanish as well when $T\to 0$.

Hiromichi Nakazato, Mikio Namiki, Saverio Pascazio

An exponential behavior at all times is derived for a solvable dynamical model in the weak-coupling, macroscopic limit. Some implications for the quantum measurement problem are discussed, in particular in connection with dissipation.

Myung-Ho Kim, Phillial Oh

We investigate the classical phase space structure of $N$ $SU(n+1)$ non-Abelian Chern-Simons (NACS) particles by first constructing the product space of associated $SU(n+1)$ bundle with ${\bf CP}^n$ as the fiber. We calculate the Poisson bracket using the symplectic structure on the associated bundle and find that the minimal substitution in the presence of

Valeri V. Dvoeglazov

The oscillator-like interaction is introduced in the equation for the particle of arbitrary spin, given by Dirac and re-written to a matrix form by Dowker.

Valeri V. Dvoeglazov

The different ways of description of the $S=0$ particle with oscillator-like interaction are considered. The results are in conformity with the previous paper of S. Bruce and P. Minning.

V. A. Novikov, L. B. Okun, A. N. Rozanov, M. I. Vysotsky

The analysis of the newest data on the leptonic $Z$-decays and $m_W$ appears to reveal the first manifestations of electroweak radiative corrections. In fact, these data differ, at the level of $2σ$, from their electroweak Born values, while they agree, to within $1σ$, with the theoretical values which take the electroweak radiative corrections into account.

I. Zahed

The singlet coupling to the topological charge density in the instanton vacuum, causes the instantons and antiinstantons to be screened over distances of the order of 1/2 fm. Dilute instanton systems behave as a free gas, while dense instanton systems behave as a plasma. The free gas behaviour is favored by a density of 1 fm$^{-4}$. Owing to the Higgs mechan

Satoshi Iso

We study the universal long-distance behaviour of the Laughlin state for the fractional quantum Hall effect and the ground state of the Calogero-Sutherland model (one dimensional $1/r^2$ interaction model). In particular, it is shown that these two wave functions coincide exactly when Laughlin state is confined in a narrow cylinder geometry. The seeming diff

H. J. de Vega, A. González--Ruiz

The Nested Bethe Ansatz is generalized to open and independent boundary conditions depending on two continuous and two discrete free parameters. This is used to find the exact eigenvectors and eigenvalues of the $A_{n-1}$ vertex models and $SU(n)$ spin chains with such boundary conditions. The solution is found for all diagonal families of solutions to the r

V. A. Rubakov, O. Yu. Shvedov

Sphalerons -- unstable static solutions of classical field equations in (d+1)-dimensional space-time -- may be viewed as euclidean solutions in d dimensions. We discuss their role in the large order asymptotics of the perturbation theory. Specifically, we calculate their contribution to the large order behaviour of the ground state energy in a quantum mechan

Stefano Borgani

The aim of this review article is to give a comprehensive description of the scaling properties detected for the distribution of cosmic structures. Due to the great variety of statistical methods to describe the large-scale structure of the Universe, I will mainly concentrate on those methods which reveal remarkable regularities and scaling in the structure

K. J. Eskola, P. Hoyer, M. Vänttinen, R. Vogt

We study the Drell-Yan process $πN \rightarrow μ^+ μ^- X$ at large $x_F$ using perturbative QCD. A higher-twist mechanism suggested by Berger and Brodsky is known to qualitatively explain the observed $x_F$ dependence of the muon angular distribution, but the predicted large $x_F$ behavior differs quantitatively from observations. We have repeated the model

Peter Orland

It is shown how to treat the degrees of freedom of Nielsen-Olesen vortices in the $3+1$-dimensional $U(1)$ higgs model by a collective coordinate method. In the london limit, where the higgs mass becomes infinite, the gauge and goldstone degrees of freedom are integrated out, resulting in the vortex world-sheet action. Introducing an ultraviolet cut-off mimi

Denis Juriev

The purpose of this very short note, which maybe considered as a comment on &#34;hep-th/9401067&#34;, is to prove the following proposition. PROPOSITION. There exist certain models of Mobilevision, in which interpretational figures are observable only in a multi--user mode in contrast to single--user ones. This result maybe interesting as for applications as

H. Oberhummer, G. Staudt

A short overview of the direct reaction mechanism and the models used for the analysis of such processes is given. Nuclear reactions proceeding through the direct mechanism and involved in solar hydrogen burning are discussed. The significance of these nuclear reactions with respect to the solar neutrino problem is investigated.

Arieh Iserles, Syvert Paul Nørsett

Given a parametrised weight function $ω(x,μ)$ such that the quotients of its consecutive moments are Möbius maps, it is possible to express the underlying biorthogonal polynomials in a closed form \cite{IN2}. In the present paper we address ourselves to two related issues. Firstly, we demonstrate that, subject to additional assumptions, every such $ω$ obeys

Arieh Iserles, Syvert Paul Nørsett

The authors have presented in \cite{IN2} a technique to generate transformations $\cal T$ of the set ${\Bbb P}_n$ of $n$th degree polynomials to itself such that if $p\in{\Bbb P}_n$ has all its zeros in $(c,d)$ then ${\cal T}\{p\}$ has all its zeros in $(a,b)$, where $(a,b)$ and $(c,d)$ are given real intervals. The technique rests upon the derivation of an

William Gasarch, Jeffry Hirst

We examine a number of results of infinite combinatorics using the techniques of reverse mathematics. Our results are inspired by similar results in recursive combinatorics. Theorems included concern colorings of graphs and bounded graphs, Euler paths, and Hamilton paths.

Donald I. Cartwright, Michael Shapiro

We see that a building whose Coxeter group is hyperbolic is itself hyperbolic. Thus any finitely generated group acting co-compactly on such a building is hyperbolic, hence automatic. We turn our attention to affine buildings and consider a group $Γ$ which acts simply transitively and in a ``type-rotating&#39;&#39; way on the vertices of a locally finite thi

Joshua Feinberg

We discuss O(N) invariant scalar field theories in 0+1 and 1+1 space-time dimensions. Combining ordinary ``Large N&#34; saddle point techniques and simple properties of the diagonal resolvent of one dimensional Schrödinger operators we find {\it exact} non-trivial (space dependent) solutions to the saddle point equations of these models in addition to the sa

Bruce W. Westbury

This paper defines a new sequence of finite dimensional algebras as quotients of the group algebras of the braid groups. This sequence depends on three homogeneous parameters and has a one-parameter family of Markov traces, and so gives a three parameter invariant of oriented links.

P. E. Gibbs

In the event symmetric approach to quantum gravity it is assumed that the fundamental laws of physics must be invariant under exchange of any two space-time events. The fact that this symmetry if obviously not observed is attributed to the possibility of a spontaneous symmetry breaking mechanism in which the residual symmetry is diffeomorphism invariance on

A. H. Chamseddine

We show that $N=2$ and $N=4$ extended supersymmetric Yang-Mills theories in four space-time dimensions could be derived as action functionals for non-commutative spaces. The coupling of $N=1$ and $N=2$ super Yang-Mills to $N=1$ and $N=2$ matter could be derived as action functionals of non-commutative spaces only for a restricted class of models where a gene