April 1994 arXiv papers — page 3

D. V. Boulatov

A model is proposed which can be regarded as a mean field approximation for pure lattice QCD and chiral field. It always possesses a phase transition between a strong coupling phase (where it reduces to a one-plaquette integral) and a non-trivial weak coupling one. For the U(N) gauge group, it is equivalent to some multi-matrix model. This analogy allows for

E. V. Shuryak, L. Xiong

Recently the first single photon spectra from CERN energy heavy-ion collisions were reported by WA80, while NA34/3 and NA38 have obtained the spectra for dileptons with the mass up to 4-5 GeV. The production rates for photons and dileptons significantly increase when reactions involving the $A_1$ meson are included. However, with the conventional expansion s

Joseph I. Kapusta, Ajit M. Srivastava

We consider the form of the chiral symmetry breaking piece of the effective potential in the linear sigma model. Surprisingly, it allows for a second local minimum at both zero and finite temperature. Even though chiral symmetry is not exact, and therefore is not restored in a true phase transition at finite temperature, this second minimum can nevertheless

F. del Aguila

In these lectures we review the simplest gauge extensions of the standard model, and the present and future limits on new weak interactions.

Hiroshi Matsukawa, Hidetoshi Fukuyama

A new method has been proposed to evaluate the frictional force in the stationary state. This method is applied to the 1-dimensional model of clean surfaces. The kinetic frictional force is seen to depend on velocity in general, but the dependence becomes weaker as the maximum static frictional force increases and in the limiting case the kinetic friction ge

N. Dupuis

At high magnetic field, the semiclassical approximation which underlies the Ginzburg-Landau theory of the mixed state of type II superconductors breaks down. In a quasi-1D superconductor with an {\it open Fermi surface}, a high magnetic field stabilizes a cascade of superconducting phases which ends in a strong reentrance of the superconducting phase. From a

I. V. Krive, R. I. Shekhter, S. M. Girvin, M. Jonson

We calculate the magnetic moment (`persistent current') in a strongly correlated electron system --- a Wigner crystal --- in a one-dimensional ballistic ring. The flux- and temperature dependence of the persistent current is shown to be essentially the same as for a system of non-interacting electrons. In contrast, by incorporating into the ring geometry

Michael Youssefmir, Bernardo Huberman

We introduce a set of local procedures that are capable of controlling distributed systems that exhibit complex dynamical behavior. These local controllers need only perturb local parameters and use local information about the state of the system. Besides eliminating the wiring and overhead needed for implementing a central controller, our procedure leads to

A. Szomoru, P. Guhathakurta, J. van Gorkom, J. Knapen

We analyze the properties of a sample of galaxies identified in a 21-cm, HI-line survey of selected areas in the Perseus-Pisces supercluster and its foreground void. Twelve fields were observed in the supercluster, five of them (target fields) centered on optically bright galaxies, and the other seven (blank fields) selected to contain no bright galaxies. We

T. A. Smecker-Hane, P. B. Stetson, J. E. Hesser, M. D. Lehnert

We report on the first in a series of studies of the Carina dwarf spheroidal galaxy, a nearby satellite of our Galaxy. Our two major results are: 1) precise BI photometry ($σ_{B-I} \simlt 0.05$ for $V \simlt 22$) for 11,489 stars in the Carina field, and 2) the detection of two, morphologically distinct, horizontal branches, which confirms that star formatio

P. Meszaros, M. J. Rees

Sudden collapse of a compact object, or coalescence of a compact binary, can generate an unsteady relativistic wind that lasts for a few seconds. The wind is likely to carry a high magnetic field; and its Lorentz factor depends on the extent to which it is 'loaded' with baryons. If the Lorentz factor is $\sim 100$, internal dissipation and shocks in

D. Nunez, H. P. de Oliveira

An expanding shell is accelerated outward by radiation from the remnant star and slowed by ram pressure and accretion as it plows into the interstellar medium. We set up the general relativistic equations of motion for such a shell. In the non-relativistic limit, the reduce to the standard Ostriker-Gunn equations. Furthermore, it is shown that the motion equ

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.

F. Bernardeau, R. Juszkiewicz, A. Dekel, F. R. bouchet

We propose a method for measuring the cosmological density parameter $Ω$ from the statistics of the divergence field, $θ\equiv H^{-1} ÷v$, the divergence of peculiar velocity, expressed in units of the Hubble constant, $H \equiv 100 h km/s/Mpc$. The velocity field is spatially smoothed over $\sim 10 h^{-1} Mpc$ to remove strongly nonlinear effects. Assuming

Robert Friedman, Zhenbo Qin

In this paper we prove that no complex surface of general type is diffeomorphic to a rational surface, thereby completing the smooth classification of rational surfaces and the proof of the Van de Ven conjecture on the smooth invariance of Kodaira dimension.

K. C. K. Chan, R. B. Mann

A one parameter family of static charged black hole solutions in $(2+1)$-dimensional general relativity minimally coupled to a dilaton $ϕ\propto ln({r\overβ})$ with a potential term $e^{bϕ}Λ$ is obtained. Their causal strutures are investigated, and thermodynamical temperature and entropy are computed. One particular black hole in the family has the same the

Samir D. Mathur

We compute the entropy of the Hawking radiation for an evaporating black hole, in 1+1 dimensions and in 3+1 dimensions. We investigate the validity of the semiclassical approximation for the evaporation process. It appears that there might be a large entropy of entanglement between the classical degrees of freedom describing the black hole and the radiation

C. T. H. Davies, K. Hornbostel, A. Langnau, G. P. Lepage

Recent results from lattice QCD simulations provide a realistic picture, based upon first principles, of~$Υ$ physics. We combine these results with the experimentally measured mass of the $Υ$~meson to obtain an accurate and reliable value for the $b$-quark's pole mass. We use two different methods, each of which yields a mass consistent with $M_b = 5.0(2

Eric D'Hoker, D. H. Phong

We analyze the analytic continuation of the formally divergent one-loop amplitude for scattering of the graviton multiplet in the Type II Superstring. In particular we obtain explicit double and single dispersion relations, formulas for all the successive branch cuts extending out to plus infinity, as well as for the decay rate of a massive string state of a

Ramil' F. Bikbaev, Vadim R. Kudashev

Dissipationless shock waves in modulational unstable one-dimensional medium are investigated on the simplest example of integrable focusing nonlinear Schr\''odinger (NS) equation. Our approach is based on the construction of special exact solution of the Whitham-NS system, which ''partially saturates'' the modulational instability.

Moti Gitik, Jiří Witzany

The Axiom of Full Reflection at a measurable cardinal has been conjectured to be equiconsitent with the existence of a coherent sequence of measures with a repeat point. However we prove that the Axiom of Full Reflection at a measurable cardinal is surprisingly equiconsistent just with the existence of a measurable cardinal. We also generalize the result to

S. L. Adler

\noindent We propose a set of rules for constructing composite leptons and quarks as triply occupied quasiparticles, in the quaternionic quantum mechanics of a pair of Harari-Shupe preons $T$ and $V$. The composites fall into two classes, those with totally antisymmetric internal wave functions, and those with internal wave functions of mixed symmetry. The m

C. S. Aulakh

We show that self-dual Nielsen Olesen (NO) vortices in $3$ dimensions give rise to a class of exact solutions when coupled to Einstein Maxwell Dilaton gravity obeying the Majumdar-Papapetrou(MP) relation between gravitational and Maxwell couplings , provided certain Chern-Simons type interactions are present. The metric may be solved for explicitly in terms

Noureddine Mohammedi

The affine current algebra for Lie superalgebras is examined. The bilinear invariant forms of the Lie superalgebra can be either degenerate or non-degenerate. We give the conditions for a Virasoro construction, in which the currents are primary fields of weight one, to exist. In certain cases, the Virasoro central charge is an integer equal to the super dime

Pablo M. Llatas, Shibaji Roy

In a recent work it has been shown that the bosonic strings could be embedded into a special class of $N=1$ fermionic strings. We argue that the superpartners of any physical state in the spectrum of this fermionic string is non-physical. So, there is no supersymmetry in the space of physical states and the embedding is, in this sense, ``trivial''. W

C. R. Hagen

It is shown that a recent claim of equivalence between three Chern-Simons theories is not tenable.

Aurelian Isar

The harmonic oscillator with dissipation is studied within the framework of the Lindblad theory for open quantum systems. By using the Wang-Uhlenbeck method, the Fokker-Planck equation, obtained from the master equation for the density operator, is solved for the Wigner distribution function, subject to either the Gaussian type or the $δ$-function type of in

T. Gisiger, M. B. Paranjape

We study the scattering of Skyrmions at low energy and large separation using the method proposed by Manton of truncation to a finite number of degrees freedom. We calculate the induced metric on the manifold of the union of gradient flow curves, which for large separation, to first non-trivial order is parametrized by the variables of the product ansatz. (p

T. Gisiger, M. B. Paranjape

We calculate nucleon-nucleon scattering at low energies and large impact parameter in the Skyrme model within the framework for soliton scattering proposed by Manton. This corresponds to a truncation of the degrees of freedom to the twelve collective coordinates which essentially describe the rigid body motion of the pair of Skyrmions. We take to its logical

A. Niégawa

Within the framework of perturbative resummation scheme of Pisarski and Braaten, the decay- or damping-rate of a moving heavy quark (muon) to leading order in weak coupling in hot QCD (QED) is examined. Although, as is well known, the conventionally-defined damping rate diverges logarithmically at the infrared limit, shown is that no such divergence appears

A. Das, M. Hott

We show that a massive fermion theory, while not invariant under the conventional chiral transformation, is invariant under a $m$-deformed chiral transformation. These transformations and the associated conserved charges are nonlocal but reduce to the usual transformations and charges when $m=0$. The $m$-deformed charges commute with helicity and satisfy the

Alexei Yu. Smirnov

There is no consistent solar model which can describe all experimental data on the solar neutrinos. The problem can be formulated essentially in a model independent way. The key points are the comparison of the Homestake and the Kamiokande data as well as the comparison of the GALLEX and SAGE results with minimal signal estimated from the solar luminosity. I

Carl H. Albright, Satyanarayan Nandi

We describe a new technique which enables one to construct an SO(10)-symmetric fermion mass matrix model at the supersymmetric grand unification scale directly from the fermion mass and mixing data at the low energy scale. Applications to two different neutrino mass and mixing scenarios are given.

Thomas E. Browder, Klaus Honscheid, Stephen Playfer

We review recent experimental results on B meson decays. These include measurements of the inclusive production of charmed and non-charmed mesons and baryons, the reconstruction of a large number of exclusive hadronic final states with charmed mesons, the search for exclusive hadronic final states without charmed mesons, and the first observation of the deca

F. A. Berends, R. Kleiss, R. Pittau

This paper studies the electroweak production of all possible four fermion states in e+ e- collisions. Since the methods employed to evaluate the complete matrix elements and phase space are very general, all four fermion final states in which the charged particles are detected can be considered. Also all kinds of experimental cuts can be imposed. With the h

Yu. Makeenko

I derive the set of recurrence relations between the amplitudes of multiparticle production at threshold in the standard large-N limit of the O(N)-symmetric phi^4$ theory which sums all relevant diagrams with arbitrary number of loops. I find an exact solution to the recurrence relations using the Gelfand--Dikii representation of the diagonal resolvent of th

Kiwoon Choi, Jihn E. Kim, Hans Peter Nilles

Some of the soft SUSY breaking parameters in hidden sector supergravity model depend on the expectation value of the hidden sector scalar potential, $<V_h>$, whose tree level value is equal to the tree level cosmological constant. The current practice of calculating soft parameters assumes that $<V_h>=0$. Quantum correction to the cosmological constant can d

E. Altshuler, A. G. Aronov, A. D. Mirlin, P. Woelfle

We consider the single particle relaxation rate of 2D electrons subject to a random magnetic field. The density of states (DOS) oscillations in a uniform magnetic field (in addition to a random one) are studied. We define a gauge invariant single particle relaxation time as a parameter describing the amplitude of DOS oscillations. Unlike the conventional cas

A. G. Aronov, A. D. Mirlin, P. Woelfle

We consider a charged quantum particle in a random magnetic field with Gaussian, delta-correlated statistics. We show that although the single particle properties are peculiar, two particle quantities such as the diffusion constant can be calculated in perturbation theory. We map the problem onto a non-linear sigma-model for Q-matrices of unitary symmetry wi

A. M. Lacasta, J. M. Sancho, Chuck Yeung

Phase separation dynamics with an initially non-uniform concentration are studied. Critical and off-critical behavior is observed simultaneously. A mechanism for an expanding phase separated region is demonstrated and the time dependence of the concentration is determined. The final equilibrium state consists of a planar interface separating one phase from t

Shuxi Li, R. K. Bhaduri

It is demonstrated that the Sutherland Hamiltonian is equivalent to particles interacting with the vector statistical interaction on the rim of a circle, to within a nonsingular gauge transformation.

M. Azzouz, Liang Chen, S. Moukouri

The ground state energy and the singlet-triplet energy gap of the antiferromagnetic Heisenberg model on a ladder is investigated using a mean field theory and the density matrix renormalization group. Spin wave theory shows that the corrections to the local magnetization are infinite. This indicates that no long range order occurs in this system. A flux-phas

Macoto Kikuchi, Nobuyasu Ito, Yutaka Okabe

On the basis of the dynamical interpretation of Monte Carlo simulations, we discuss the relation of the equilibrium relaxation time, the susceptibility and the statistical error. We introduce a new quantity called {\it the statistical dependence time} $τ_{dep}$, which gives the reduction factor for the statistical degree of freedom due to the dynamical corre

F. B. Anders, N. Grewe

We present selected results from combined analytical and numerical studies of the Anderson-impurity model within the framework of infinite order perturbation theory with respect to the hybridization. Our approximation goes considerably beyond the well known non\-cross\-ing approximation (NCA): The re-summations include skeleton diagrams up to infinite order

Guinevere Kauffmann

We show that the rapid evolution in the fraction of blue, star-forming galaxies seen in clusters as a function of redshift (the Butcher-Oemler effect) can be explained very simply if structure formation in the universe proceeeds hierarchically. We show that a rich cluster observed at high redshift has had a significantly different evolutionary history to a c

v. A. Gritsenko, G. K. Sankaran

We show that the (compactified) moduli space of abelian surfaces with a polarisation of type $(1,p^2)$ is of general type for $p \ge 11$, improving a result of O&#39;Grady.

J. W. Moffat, D. C. Tatarski

A local void in the globally Friedmann-Robertson-Walker cosmological model with the critical density ($Ω_{0}=1$) is studied. The inhomogeneity is described using a Lema\^ıtre-Tolman-Bondi solution for a spherically symmetric distribution of matter. The scale of the central underdense region is $\sim 150$ Mpc. We investigate the effects this has on the cosmol

John W. Barrett

A first order form of Regge calculus is defined in the spirit of Palatini&#39;s action for general relativity. The extra independent variables are the interior dihedral angles of a simplex, with conjugate variables the areas of the triangles. There is a discussion of the extent to which these areas can be used to parameterise the space of edge lengths of a s

Abdellatif Abada, Joerg Aichelin

We investigate the time evolution of a quark antiquark plasma by solving numerically the relativistic transport equations derived on the Hartree level from the Nambu-Jona-Lasinio model. We find that the phase transition in the expanding quark antiquark plasma is different as compared to that in a static plasma. The expansion competes with the transition and

Michiyasu Nagasawa, Jun&#39;ichi Yokoyama

Time evolution of a circular cosmic string loop is investigated by numerically solving the field equations for the scalar and the gauge fields consisting of the vortex. It is shown that the result agrees with an analytic estimate based on the Nambu-Goto action, which supports its validity in analyzing nonstraight and rapidly moving strings.

Evgeny V. Doktorov

A method is proposed of obtaining (2+1)-dimensional non- linear equations with non-analytic dispersion relations. Bilocal formalism is shown to make it possible to represent these equations in a form close to that for their counterparts in 1+1 dimensions.

Evgeny V. Doktorov, Rafael A. Vlasov

Near-soliton scanning light-beam propagation in media with both delayed-response Kerr-type and thermal nonlinearities is analyzed. The delayed-response part of the Kerr nonlinearity is shown to be competitive as compared to the thermal nonlinearity, and relevant contributions to a distortion of the soliton form and phase can be mutually compensated. This qua

Ramil&#39; F. Bikbaev, Vadim R. Kudashev

In the framework of Gurevich and Pitaevskii approach [1] we construct modulated by Whitham [2] solution of nonlinear Shrodinger (NS) equation partially saturating the modulational instability. This solution describes new scenario of monochromatic wave evolution in NS equation which leads to generation of new phase and oscillation region.

Mikhail I. Ostrovskii

The paper is devoted to two particular cases of the following general problem. Let $α$ and $β$ be two types of bases in Banach spaces. Let a Banach space $X$ has bases of both types and a subspace $M\subset X^*$ contains the sequence of biorthogonal functionals of some $α$-basis in $X$. Does $M$ contain a sequence of biorthogonal functionals of some $β$-basi

Alexander Koldobsky

For every $n\geq 3,$ we construct an $n$-dimensional Banach space which is isometric to a subspace of $L_{1/2}$ but is not isometric to a subspace of $L_1.$ The isomorphic version of this problem (posed by S. Kwapien in 1969) is still open. Another example gives a Banach subspace of $L_{1/4}$ which does not embed isometrically in $L_{1/2}.$ Note that, from t

J. L. Vazquez-Bello

Ten dimensional supersymmetric Yang-Mills theory may be described, in the light-cone gauge, in terms of either a vector or spinor superfield satisfying certain projection conditions (type I or II). These have been presented in a $ SO(9,1) $ form, and used to construct spinning superparticle theories in extended spaces. This letter presents the covariant quan

A. Marshakov

We discuss different formulations and approaches to string theory and $ 2d$ quantum gravity. The generic idea to get a unique description of {\it many} different string vacua altogether is demonstrated on the examples in $ 2d$ conformal, topological and matrix formulations. The last one naturally brings us to the appearance of classical integrable systems in

Hitoshi Nishino

Abstrct: We show that the action of self-dual supersymmetric Yang-Mills theory in four-dimensions, which describes the consistent massless background fields for $~N=2$~ superstring, generates the actions for $~N=1$~ and $~N=2$~ supersymmetric non-Abelian Chern-Simons theories in three-dimensions after appropriate dimensional reductions. Since the latters pla

N. Itzhaki

We discuss time measurement in quantum gravity. Using general relativity for large distances and the uncertainty principle we find a minimum time interval of the order of the Planck time, therefore the uncertainty in time measurment is bounded from below.

Jun&#39;ichi Shiraishi

A Heisenberg-Clifford realization of a deformed $U(sl_{2})$ by two parameters $p$ and $q$ is discussed. The commutation relations for this deformed algebra have interesting connection with the theta functions.

M. Navarro, J. Guerrero, V. Aldaya

In this paper we regard the dynamics obtained from Fermat principle as begin the classical theory of light. We (first-)quantize the action and show how close we can get to the Maxwell theory. We show that Quantum Geometric Optics is not a theory of fields in curved space. Considering Classical Mechanics to be on the same footing, we show the parallelism betw

Kh. S. Nirov, A. V. Razumov

An analysis of the state space in the BRST--quantization in the Schroedinger representation is performed on the basis of the results obtained earlier in the framework of the Fock space representation. It is shown that to get satisfactory results it is necessary to have from the very beginning a meaningful definition of the total state space.

Leung Chim

The 2D off-critical q-state Potts model with boundaries was studied as a factorizable relativistic scattering theory. The scattering S-matrices for particles reflecting off the boundaries were obtained for the cases of ``fixed&#39;&#39; and ``free&#39;&#39; boundary conditions. In the Ising limit, the computed results agreed with recent work[5].

Johannes Blümlein, Edward Boos, Alexander Pukhov

The pair production cross section for scalar and vector leptoquarks at $ep$ colliders is calculated for the case of photon--gluon fusion. In a model independent analysis we consider the most general $C$ and $P$ conserving couplings of gluons and photons to both scalar and vector leptoquarks described by an effective low--energy Lagangian which obeys $U(1)_{e

The CLEO collaboration

Using data from the CLEO II detector at CESR, we measure ${\cal B}(τ^\pm\rightarrow h^\pmπ^0ν_τ)$ where $h^\pm$ refers to either $π^\pm$ or $K^\pm$. We use three different methods to measure this branching fraction. The combined result is ${\cal B}(τ^\pm\rightarrow h^\pmπ^0ν_τ) = 0.2587 \pm 0.0012 \pm 0.0042$, in good agreement with Standard Model prediction

A. A. Bel&#39;kov, A. V. Lanyov, A. Schaale, S. Scherer

Starting from a QCD inspired bilocal quark interaction we obtain a local effective meson lagrangian. In contrast to previous local (NJL-like) approaches, we include nonlocal corrections related to the finite meson size which we characterize by a small parameter. After bosonization using the heat-kernel method we predict the structure coefficients of the Gass

Waikwok Kwong, S. P. Rosen

The Kamiokande measurement of energetic Boron-8 neutrinos from the sun is used to set a lower bound on the contribution of the same neutrinos to the signal in the \Chlorine\ experiment. Implications for Beryllium-7 neutrinos are discussed.

S. Barshay, P. Heiliger

We demonstrate the existence of an anomalous structure in the data on the diffractive elastic scattering of hadrons at high energies and small momentum transfer. We analyze five sets of experimental data on $p(\overline{p})-p $ scattering from five different experiments with colliding beams, ranging from the first-- and second--generation experiments at $\sq

S. Dittmaier, D. Schildknecht, K. Kolodziej, M. Kuroda

We elaborate on a recently suggested effective Lagrangian for charged-current and neutral-current electroweak interactions which in comparison with the standard electroweak theory contains three free parameters $Δx, Δy$, $\varepsilon$ which quantify different sources for violations of $SU(2)$ symmetry. Within the standard $SU(2)_I \times U(1)_Y$ electroweak

Wolfgang Kilian, Thorsten Ohl

We discuss the quantum action principles and equations of motion for Heavy Quark Effective Field Theory. We prove the so-called equivalence theorem for HQEFT which states that the physical predictions of HQEFT are independent from the choice of interpolating fields. En passant we point out that HQEFT is in fact more subtle than the quantum mechanical Foldy-W

D. P. Roy

The Higgs particle can have dominantly invisible decay in a large class of Majoron models as well as some SUSY models. The LEP signal and mass limit for a Higgs particle undergoing invisible decay are explored. They are found to be very similar to those for the standard model decay. The best signatures and discovery limit for an invisibly decaying Higgs part

Patrick Huet, Eric Sather

We analyze the mechanism of electroweak baryogenesis proposed by Farrar and Shaposhnikov in which the phase of the CKM mixing matrix is the only source of $CP$ violation. This mechanism is based on a phase separation of baryons via the scattering of quasiparticles by the wall of an expanding bubble produced at the electroweak phase transition. In agreement w

Andrei L. Talapov, Lev N. Shchur

We describe results of the cluster algorithm Special Purpose Processor simulations of the 2D Ising model with impurity bonds. Use of large lattices, with the number of spins up to $10^6$, permitted to define critical region of temperatures, where both finite size corrections and corrections to scaling are small. High accuracy data unambiguously show increase

A. Agodi, G. Andronico, M. Consoli

We present a lattice computation of the effective potential for O(2)-invariant $(λΦ^4)_4$ theory in the region of bare parameters corresponding to a classically scale-invariant theory. As expected from ``triviality&#39;&#39; and as in the one-component theory, we find very good agreement with the one-loop prediction, while a perturbative leading-log improvem

D. B. Abraham, T. J. Newman, G. M. Schütz

We present an exact solution to an interface model representing the dynamics of a domain wall in a two-phase Ising system. The model is microscopically motivated, yet we find that in the scaling regime our results are consistent with those obtained previously from a phenomenological, coarse-grained Langevin approach.

A. A. Nersesyan, A. Luther

The $S=1/2$ XXZ spin chain with the staggered XY anisotropy $$ H = J \sum_{n}^{N} (S^{x}_{n} S^{x}_{n+1} + S^{y}_{n} S^{y}_{n+1} + ΔS^{z}_{n} S^{z}_{n+1}) - δ\sum_{n}^{N} (-1)^{n} (S^{x}_{n} S^{x}_{n+1} - S^{y}_{n} S^{y}_{n+1}) $$ is shown to possess gapless, Luttinger-liquid-like phases in a wide range of its parameters: the XY-like phase and spin nematic p

Johansson, G. Nave, M. Geller, A. J. Sauval

The combined laboratory and solar analysis of the highly-excited subconfigurations 4f and 5g of Fe I has allowed us to classify 87 lines of the 4f-5g supermultiplet in the spectral region 2545-2585 cm-1. The level structure of these JK-coupled configurations is predicted by semiempirical calculations and the quadrupolic approximation. Semiempirical gf-values

I. G. Nave, S. Johansson, R. C. M. Learner, A. P. Thorne

We have recorded spectra of iron-neon and iron-argon hollow cathode lamps in the region 1700A -- 5um (59000 -- 2000cm-1), with Fourier transform (FT) spectrometers at the National Solar Observatory, Tucson, Arizona, U.S.A. and Imperial College, London, U.K., and with a high resolution grating spectrograph at the National Institute of Standards and Technology

Amotz Shemi

Relativistic flows resulting from sudden explosive events upscatter ambient interstellar photons of local radiation fields. For Lorentz factor $ > 100$ and dense optical - UV radiation fields the emergent signal is a typical gamma ray burst. Presumably the explosions occur in dense globular clusters or in galactic nuclei, at cosmological distances.

Jennifer J. Wiseman, Fred C. Adams

We present an analysis of IRAS maps of five molecular clouds: Orion, Ophiuchus, Perseus, Taurus, and Lupus. For the classification and description of these astrophysical maps, we use a newly developed technique which considers all maps of a given type to be elements of a pseudometric space. For each physical characteristic of interest, this formal system ass

Fred C. Adams, Jennifer J. Wiseman

We extend a newly developed formal system for the description of astrophysical maps. In this formalism, we consider the difference between maps to be the distance between elements of a pseudometric space (the space of all such maps). This ansatz allows us to measure quantitatively the difference between any two maps and to order the space of all maps. For ea

T. Buchert, A. L. Melott, A. G. Weiss

We report on a series of tests of Newtonian Lagrangian perturbation schemes using N--body simulations for various power--spectra with scale--independent indices in the range $-3$ to $+1$. The models have been evolved deeply into the non--linear regime of structure formation in order to probe the dynamical and statistical performance of the Lagrangian perturb

R. Durrer, M. Sakellariadou

We show that there are inflationary models for which perturbations in the energy momentum tensor, which are of second order in the scalar field, cannot be neglected. We first specify the conditions under which the usual first order perturbations are absent. We then analyze classically, the growth and decay of our new type of perturbations for one mode of flu

S. Covino, L. E. Pasinetti Fracassini, M. L. Malagnini, A. Buzzoni

Buzzoni&#39;s (1989) grid of synthetic spectral energy distributions, representative of old stellar populations, was used to derive colours in different photometric systems, and to compare the theoretical predictions with the observational data referring to about $120$ globular clusters in the Galaxy and to $159$ objects of the globular cluster system of M31

Hans - Juergen Schmidt

We analyze the presumptions which lead to instabilities in theories of order higher than second. That type of fourth order gravity which leads to an inflationary (quasi de Sitter) period of cosmic evolution by inclusion of one curvature squared term (i.e. the Starobinsky model) is used as an example. The corresponding Hamiltonian formulation (which is necess

E. Kiritsis, C. Kounnas, D. Luest

We analyse the stringy gravitational wave background based on the current algebra $E^{c}_{2}$. We determine its exact spectrum and construct the modular invariant vacuum energy. The corresponding N=1 extension is also constructed. The algebra is again mapped to free bosons and fermions and we show that this background has N=4 (N=2) unbroken spacetime supersy

Georg Junker, Hajo Leschke

Revised Version with corrections of misprints.

A. Dimakis, F. Müller-Hoissen

Differential calculus on discrete sets is developed in the spirit of noncommutative geometry. Any differential algebra on a discrete set can be regarded as a `reduction&#39; of the `universal differential algebra&#39; and this allows a systematic exploration of differential algebras on a given set. Associated with a differential algebra is a (di)graph where

Kikuo Harigaya

Optical absorption spectra of C60^6- are theoretically investigated in order to analyze the optical properties of alkali metal doped fullerites A6C60. We use a tight binding model with long ranged Coulomb interactions and bond disorder. Optical spectra are obtained by the Hartree-Fock approximation and the CI method. The Coulomb interaction parameters which

A. O. Barvinsky, V. P. Frolov, A. I. Zelnikov

Recently it was proposed to explain the dynamical origin of the entropy of a black hole by identifying its dynamical degrees of freedom with states of quantum fields propagating in the black-hole&#39;s interior. The present paper contains the further development of this approach. The no-boundary proposal (analogous to the Hartle-Hawking no-boundary proposal

T. Brodkorb, E. Mirkes

We present a new parton level Monte Carlo program for the calculation of jet cross sections in Deep Inelastic Scattering based on Born and next-to-leading order matrix elements. Using a class of invariant jet definition schemes, the program allows for the calculation of differential distributions of jet cross sections in the basic kinematical variables (like

P. Mohr, H. Abele, U. Atzrott, G. Staudt

Double--folded optical $α$--nucleus potentials can be used to calculate elastic scattering cross sections in a wide mass-- and energy region. Because of the systematic behavior of the potential parameters we are able to obtain reliable optical potentials for astrophysically relevant reactions even without scattering data in low--energy region. As example we

Wolfram Koepf, Dieter Schmersau

In \cite{Koe92}--\cite{Koe93c} the first author published an algorithm for the conversion of analytic functions for which derivative rules are given into their representing power series $\sum\limits_{k=0}^{\infty}a_{k}z^{k}$ at the origin and vice versa, implementations of which exist in {\sc Mathematica} \cite{Wol}, (s.\ \cite{Koe93c}), {\sc Maple} \cite{Ma

Wolfram Koepf, Dieter Schmersau

We consider the family B-tilde of bounded nonvanishing analytic functions f(z) = a_0 + a_1 z + a_2 z^2 + ... in the unit disk. The coefficient problem had been extensively investigated, and it is known that |a_n| <= 2/e for n=1,2,3, and 4. That this inequality may hold for n in N, is know as the Kryż conjecture. It turns out that for f in B-tilde with a_0 =

Wolfram Koepf

In this article we present a method to implement orthogonal polynomials and many other special functions in Computer Algebra systems enabling the user to work with those functions appropriately, and in particular to verify different types of identities for those functions. Some of these identities like differential equations, power series representations, an

Wolfram Koepf

Formal Laurent-Puiseux series are important in many branches of mathematics. This paper presents a {\it Mathematica} implementation of algorithms developed by the author for converting between certain classes of functions and their equivalent representing series. The package {\tt PowerSeries} handles functions of rational, exponential, and hypergeometric typ

Dominik Gruntz, Wolfram Koepf

In this article we will describe the \Maple\ implementation of an algorithm presented in~\cite{Koe92}--\cite{Koeortho} which computes an {\em exact\/} formal power series (FPS) of a given function. This procedure will enable the user to reproduce most of the results of the extensive bibliography on series~\cite{Han}. We will give an overview of the algorithm

A. A. Andrianov, M. V. Ioffe, D. N. Nishnianidze

We give the classification of second-order polynomial SUSY Quantum Mechanics in one and two dimensions. The particular attention is paid to the irreducible supercharges which cannot be built by repetition of ordinary Darboux transformations. In two dimensions it is found that the binomial superalgebra leads to the dynamic symmetry generated by a central char

O. Castaños, R. López-Peña, V. I. Man&#39;ko

It is shown that linear time-dependent invariants for arbitrary multi\-dimensional quadratic systems can be obtained from the Lagrangian and Hamiltonian formulation procedures by considering a variation of coordinates and momenta that follows the classical trajectory and defines a noetherian symmetry transformation.

Srinandan Dasmahapatra

We outline the relationship between the thermodynamic densities and quasi-particle descriptions of spectra of RSOS models with an underlying Bethe equation. We use this to prove completeness of states in some cases and then give an algorithm for the construction of branching functions of their emergent conformal field theories. Starting from the Bethe equati