January 1997 arXiv papers — page 7

F. Sylos Labini, L. Pietronero, M. Montuori

In this lecture we will try to address the "frequently asked questions about fractals" in the field of large scale galaxy distribution. This paper takes its origin from a very interesting discussion we had at this meeting. A lot of points were raised, and we try to make clear the fundamental ones.

R. J. Smith, M. J. Hudson, J. R. Lucey, J. Steel

We present results of a new study of peculiar motions of 7 clusters in the Perseus-Pisces (PP) region, using the Fundamental Plane as a distance indicator. The sample is calibrated by reference to 9 additional clusters with data from the literature. Careful attention is paid to the matching of spectroscopic and photometric data from several sources. For six

David Merritt

Statler (1987) demonstrated that self-consistent triaxial models with the perfect density law could be constructed for virtually any choice of axis ratios. His experiments are repeated here using triaxial mass models based on Jaffe's density law, which has a central density that diverges as 1/r^2, similar to what is observed in low-luminosity elliptical

G. Piotto, A. M. Cool, I. R. King

From deep color-magnitude arrays made from V and I images taken with the Hubble Space Telescope's WFPC2 camera we have determined luminosity functions (LFs) down to a level that corresponds to about 0.13 solar masses, for the low-metal-abundance globular clusters M15, M30, M92, and NGC 6397. Because of the similarity of the metallicities of these cluster

G. Piotto, C. Sosin, I. R. King, S. G. Djorgovski

In this paper we present preliminary results from our HST project aimed at exploring the connection between the stellar dynamics and stellar evolution in the cores of high-density globular clusters. We illustrate the discovery of horizontal branches (HB) with extended blue tails in the very metal rich globular clusters NGC 6388 ([Fe/H]=-0.6) and NGC 6441 ([F

C. Sosin, G. Piotto, S. G. Djorgovski, I. R. King

In this paper we present the 13 B and V color-magnitude diagrams discussed by Piotto et al. in the same Procedings. The data have been collected with the WFPC2 camera on HST. We emphasize the discovery of blue horizontal branches in the two metal rich globular clusters NGC 6388 and NGC 6441, and the four-mode HB of NGC 2808. The significance of the gaps in t

Marek J. Kukula, James S. Dunlop, David H. Hughes, Steve Rawlings

Although radio-quiet quasars (RQQs), which constitute the majority of optically-identified quasar samples, are by no means radio silent the properties of their radio emission are only poorly understood. We present the results of a multi-frequency VLA study of 27 low-redshift RQQs. In general, we find that the properties of the radio sources in RQQs are consi

S. Prins, M. van der Klis

We present a study of the persistent X-ray emission from the low-mass X-ray binary 4U 1636-53 based ont he entire archival EXOSAT ME data set. We per- formed a homogeneous analysis of all five EXOSAT observations in terms of the correlated rapid X-ray variability and X-ray spectral properties by means of power spectra, and colour-colour and hardness-intensit

August E. Evrard

The mean intracluster gas fraction of X-ray clusters within their hydrostatic regions is derived from recent observational compilations of David, Jones & Forman and White & Fabian. At radii encompassing a mean density 500 times the critical value, the individual sample bi-weight means are moderately ($2.4 σ$) discrepant; revising binding masses with a virial

Valter Moretti

The local $ζ-$function approach is implemented to regularize the natural path integral definition of the geometric entropy in the large mass black hole Euclidean manifold. The case of a massless field coupled with the (off-shell) singular curvature is considered. It is proved that the geometric entropy is independent of the curvature coupling parameter $ξ$ a

S. Nonnenmacher

Using the Bargmann-Husimi representation of quantum mechanics on a torus phase space, we study analytically eigenstates of quantized cat maps. The linearity of these maps implies a close relationship between classically invariant sublattices on the one hand, and the patterns (or `constellations') of Husimi zeros of certain quantum eigenstates on the othe

B. Basu-Mallick, Anjan Kundu

It is well known through a recent work of Bernard, Gaudin, Haldane and Pasquier (BGHP) that the usual spin Calogero-Sutherland (CS) model, containing particles with $M$ internal degrees of freedom, respects the $Y(gl_M)$ Yangian symmetry. By following and suitably modifying the approach of BGHP, in this article we construct a novel class of spin CS models wh

G. J. Mathews, J. R. Wilson

We analyze several aspects of the recently noted neutron star collapse instability in close binary systems. We utilize (3+1) dimensional and spherical numerical general relativistic hydrodynamics to study the origin, evolution, and parametric sensitivity of this instability. We derive the modified conditions of hydrostatic equilibrium for the stars in the cu

Michel Bauer, Frank Thuillier

After a review of several methods designed to produce equivariant cohomology classes, we apply one introduced by Berline, Getzler and Vergne, to get a family of representatives of the universal Thom class of a vector bundle. Surprisingly, this family does not contain the representative given by Matha\"ı and Quillen. However it contains a particularly sim

Henar Herrero, Hermann Riecke

Localized traveling-wave pulses and holes, i.e. localized regions of vanishing wave amplitude, are investigated in a real Ginzburg-Landau equation coupled to a long-wave mode. In certain parameter regimes the pulses exhibit a Hopf bifurcation which leads to a breathing motion. Subsequently the oscillations undergo period-doubling bifurcations and become chao

Vadim Zeitlin

We are studying finite fermion density states in Maxwell QED$_{2+1}$ with external magnetic field. It is shown that at any fermion density the energy of some magnetized states may be less than that of the state with the same density, but no magnetic field. Magnetized states are described by the effective Maxwell-Chern-Simons QED$_{2+1}$ Lagrangian with gauge

A. M. Kotzinian, P. J. Mulders

We consider the leading order result for polarized leptoproduction, putting emphasis on transverse momentum dependent effects appearing in azimuthal asymmetries. Measurements of weighted cross sections enable extraction of the distribution of transversely polarized quarks. We focus on the distribution in a longitudinally polarized hadron and estimate the exp

Y. Ikebe, K. Makishima, H. Ezawa, Y. Fukazawa

The temperature and abundance structure in the intracluster medium (ICM) of the Hydra-A cluster of galaxies is studied with ASCA and ROSAT. The effect of the large extended outskirts in the point-spread function of the X-Ray Telescope on ASCA is included in this analysis. In the X-ray brightness profile, the strong central excess above a single beta-model, i

Michael Turner, Martin White

The inflationary prediction of a flat Universe is at odds with current determinations of the matter density (Omega_M~0.2-0.4). This dilemma can be resolved if a smooth component contributes the remaining energy density (Omega_X=1-Omega_M). We parameterize the smooth component by its equation of state, p_X=w rho_X, and show that xCDM with w~-0.6, Omega_M~0.3

A. H. Chamseddine

A supersymmetric theory in two-dimensions has enough data to define a noncommutative space thus making it possible to use all tools of noncommutative geometry. In particular, we apply this to the N=1 supersymmetric non-linear sigma model and derive an expression for the generalized loop space Dirac operator, in presence of a general background, using canonic

William F. Palmer, Emmanuel A. Paschos, Peter H. Soldan

We combine the NRQCD formalism for the inclusive color singlet and octet production of charmonium states with the parton and the ACCMM model, respectively, and calculate the momentum distribution in the decay B-->J/psi+X. Neglecting the kinematics of soft gluon radiation, we find that the motion of the b quark in the bound state can account, to a large exten

E. A. Kuraev

The lowest order QED radiative corrections to the cross-section of the recharged process of transition of two charged pions to two neutral ones and to the pionium life time are calculated in frames of scalar QED. It is argued that the ultraviolet cut--off of the loop momentum is to be chosen of order of $ρ$ meson mass. This fact permits to perform the calcul

Michael B. Green, Michael Gutperle

Scattering of fundamental states of type IIB supergravity and superstring theory is discussed at low orders in perturbation theory in the background of a D-instanton. The integration over fermionic zero modes in both the low energy supergravity and in the string theory leads to explicit nonperturbative terms in the effective action. These include a single in

O. M. Kiselev

The linearized Davey-Stewartson equation with varing coefficients is solved by Fourier method. The approach uses the inverse scattering transform for the Davey-Stewartson equation.

Luiz A. Ferreira

We point out that a common feature of integrable hierarchies presenting soliton solutions is the existence of some special ``vacuum solutions'' such that the Lax operators evaluated on them, lie in some abelian subalgebra of the associated Kac-Moody algebra. The soliton solutions are constructed out of those ``vacuum solitons'' by the dressin

H. S. Blas Achic, L. A. Ferreira, J. F. Gomes, A. H. Zimerman

We give the correct prescriptions for the terms involving the inverse of the derivative of the delta function, in the Hamiltonian structures of the AKNS and DNLS systems, in order for the Jacobi identities to hold. We also establish that the sl(2) AKNS and DNLS systems are tri-Hamiltonians and construct two compatible Hamiltonian structures for the sl(3) AKN

Nicolas Gisin, Ian C Percival

Deeper insight leads to better practice. We show how the study of the foundations of quantum mechanics has led to new pictures of open systems and to a method of computation which is practical and can be used where others cannot. We illustrate the power of the new method by a series of pictures that show the emergence of classical features in a quantum world

N. Aizawa

Tensor products of irreducible representations of the Jordanian quantum algebras U_h(sl(2)) and U_h(su(1,1)) are considered. For both the highest weight finite dimensional representations of U_h(sl(2)) and lowest weight infinite dimensional ones of U_h(su(1,1)), it is shown that tensor product representations are reducible and that the decomposition rules to

Wenbin Zhang, Jorge Vinals

A quasi-potential approximation to the Navier-Stokes equation for low viscosity fluids is developed to study pattern formation in parametric surface waves driven by a force that has two frequency components. A bicritical line separating regions of instability to either one of the driving frequencies is explicitly obtained, and compared with experiments invol

Cristopher Moore

We show that a wide variety of non-linear cellular automata (CAs) can be decomposed into a quasidirect product of linear ones. These CAs can be predicted by parallel circuits of depth O(log^2 t) using gates with binary inputs, or O(log t) depth if ``sum mod p'' gates with an unbounded number of inputs are allowed. Thus these CAs can be predicted by (

M. Jaminon, B. Van den Bossche

A scaled SU(3) Nambu - Jona-Lasinio Lagrangian is used to compute the mass of the nine scalar mesons in the vacuum and the mass of the gluball. It is shown that a suitable choice of the vacuum gluon condensate allows to reproduce the experimental masses of the scalar mesons except for the {$K^*_{0}$}(1430). This choice corresponds to a weak coupling between

R. Bijker, A. Leviatan

We discuss recent calculations of electromagnetic form factors and strong decay widths of nucleon and delta resonances. The calculations are done in a collective constituent model of the nucleon, in which the baryons are interpreted as rotations and vibrations of an oblate top.

G. S. Guralnik

I outline the basics of numerical solution of quantum field theory using the Source Galerkin method. This method is based on an analysis of the functional differential equations of a field theory in the presence of external sources. This approach is particularly powerful because it naturally allows the inclusion of symmetry information and avoids the fermion

Hisao Suzuki

The conifold singularities in the type-II string are considered as the points of phase transition. In some cases, these singularities can be understood in the framework of the conventional fields theores as the points of enhanced gauge symmetry. We consider a class of three moduli Type-II strings. It is shown the periods can be written in the form of hyperge

Alexander L. Bondarev

A covariant method is proposed for calculating the amplitudes of processes involving polarized spin 1/2 particles. It is suitable for calculating the interference terms in the cross sections of such processes. As an illustration, expressions are given for the amplitudes of electron-electron scattering in the lowest order of perturbation theory and expression

Alexander L. Bondarev

Two approaches to calculations' minimization in High Energy Physics are considered. The first one is the method of covariant calculations for the amplitudes of processes with polarized Dirac particles. The second one connects with the possibility to reduce the expressions for the traces of products of ten and more Dirac gamma-matrices.

Alexander L. Bondarev

General scheme for covariant calculation of the amplitudes of processes with the polarized Dirac particles is considered. It is so concretized that the obtained expressions can be used for calculation of the amplitudes of processes with interfering diagrams. As an illustration the expressions for the amplitudes of processes with massless particles are presen

Alexander L. Bondarev

Schouten's identity is used to obtain a new identity in Minkowski space. Some applications of the new identity in high-energy physics are considered, including the possibility of significant shortening of the expressions for the traces of products of ten and more Dirac gamma-matrices.

G. Boyd

Tempering is used to change the quark mass while remaining in equilibrium between the trajectories of a standard hybrid Monte Carlo simulation of four flavours of staggered fermions. The algorithm is faster for small enough quark masses, and particularly so when more than one mass is required.

K. Wyatt Merritt

This paper summarizes searches at the Fermilab Tevatron for a wide variety of signatures for physics beyond the Standard Model. These include searches for supersymmetric particles, in the two collider detectors and in one fixed target experiment. Also covered are searches for leptoquarks, dijet resonances, heavy gauge bosons, and particles from a fourth gene

Giampiero Esposito, Cosimo Stornaiolo

This paper studies the application of multimomentum maps to the constraint analysis of general relativity on null hypersurfaces. It is shown that, unlike the case of spacelike hypersurfaces, some constraints which are second class in the Hamiltonian formalism turn out to contribute to the multimomentum map. To recover the whole set of secondary constraints f

Louis Marchildon

We investigate Lie symmetries of Einstein's vacuum equations in N dimensions, with a cosmological term. For this purpose, we first write down the second prolongation of the symmetry generating vector fields, and compute its action on Einstein's equations. Instead of setting to zero the coefficients of all independent partial derivatives (which involv

H. Kubotani, T. Uesugi, M. Morikawa, A. Sugamoto

We discuss the classicalization of a quantum state induced by an environment in the inflationary stage of the universe. The classicalization is necessary for the homogeneous ground sate to become classical non-homogeneous one accompanied with the statistical fluctuation, which is a plausible candidate for the seeds of structure formation. Using simple models

De Leo Stefano, Rotelli Pietro

Complex analyticity is generalized to hypercomplex functions, quaternion or octonion, in such a manner that it includes the standard complex definition and does not reduce analytic functions to a trivial class. A brief comparison with other definitions is presented.

C. -L. Ho, M. -J. Liao

We study the low temperature properties of two-dimensional ideal gases of generalized statistics in a uniform magnetic field. The generalized statistics considered here are the parafermion statistics and the exclusion statistics. Similarity in the behaviours of the parafermion gas of finite order $p$ and the gas with exclusion coefficient $g=1/p$ at very low

R. M. L. Evans, W. C. K. Poon

By analytically solving some simple models of phase-ordering kinetics, we suggest a mechanism for the onset of non-equilibrium behaviour in colloid-polymer mixtures. These mixtures can function as models of atomic systems; their physics therefore impinges on many areas of thermodynamics and phase-ordering. An exact solution is found for the motion of a singl

R. M. L. Evans, M. E. Cates

We find analytical solutions to the Cahn-Hilliard equation for the dynamics of an interface in a system with a conserved order parameter (Model B). We show that, although steady-state solutions of Model B are unphysical in the far-field, they shed light on the local dynamics of an interface. Exact solutions are given for a particular class of order-parameter

S. Tornow, V. Zevin, G. Zwicknagl

The large-degeneracy expansion for dilute magnetic alloys is extended to account for conduction electrons interactions. Particular attention is paid to the renormalization of the hybridization vertex which affects the low-energy excitations. As a first example, we calculate the enhanced characteristic energy $k_BT_0$ in the limit of weakly correlated conduct

Beate Paulus, Fa-Jian Shi, Hermann Stoll

Ground state properties of SiC, AlN, GaN and InN in the zinc-blende and wurtzite structures are determined using an ab initio scheme. For the self-consistent field part of the calculations, the Hartree-Fock program Crystal has been used. Correlation contributions are evaluated using the coupled-cluster approach with single and double excitations. This is don

Iddo Ussishkin, Ady Stern

We consider the Coulomb drag between two layers of two-dimensional electronic gases subject to a strong magnetic field. We first focus on the case in which the electronic density is such that the Landau level filling fraction $ν$ in each layer is at, or close to, $ν=1/2$. Discussing the coupling between the layers in purely electronic terms, we show that the

O. M. Braun, T. Dauxois, M. V. Paliy, M. Peyrard

The diffusion of a two-dimensional array of particles driven by a constant force in the presence of a periodic external potential exhibits a hierarchy of dynamical phase transitions when the driving force is varied. This behavior can be explained by a simple phenomenological approach which reduces the system of strongly interacting particles to weakly intera

Cristopher Moore

We study cellular automata where the state at each site is decided by a majority vote of the sites in its neighborhood. These are equivalent, for a restricted set of initial conditions, to non-zero probability transitions in single spin-flip dynamics of the Ising model at zero temperature. We show that in three or more dimensions these systems can simulate B

Zacharias A. M. Protogeros, David H. Weinberg

We measure the topology (genus) of isodensity contour surfaces in volume limited subsets of the 1.2 Jy IRAS redshift survey, for smoothing scales $λ=4\hmpc$, $7\hmpc$, and $12\hmpc$. At $12\hmpc$, the observed genus curve has a symmetric form similar to that predicted for a Gaussian random field. At the shorter smoothing lengths, the observed genus curve sho

Paola Belloni

Narrow band multifilter photometry of the galaxy populations of four galaxy clusters at z=0.4-0.5 has provided us with a sample of 73 E+A galaxies which are secure cluster members. For 34 of them HST images are available (WFPC2). We have determined surface brigthness profiles and by means of an exponential or r^1/4 law fit we have classified the galaxies on

Marc Gagne, Jean-Pierre Caillault, John R. Stauffer, Jeffrey L. Linsky

We report the discovery of large-amplitude, periodic X-ray emission from the O7 V star theta^1 Orionis C, the central star of the Orion Nebula. Ten ROSAT HRI snapshots of the Trapezium cluster taken over the course of 21 days show that the count rate of theta^1 Ori C varies from 0.26 to 0.41 counts/s with a clear 15-day period. The soft X-ray variations have

Duncan A. Forbes, Carl J. Grillmair, R. Chris Smith

The Sombrero galaxy, NGC 4594, contains the most numerous globular cluster system of any nearby spiral. It is an ideal candidate in which to study the globular clusters and contrast them with those in Local Group spirals. Here we present B and I imaging from the CTIO Schmidt telescope which gives a field-of-view of 31' x 31'. Using DAOPHOT we have de

C. A. Collins, D. J. Burke, A. K. Romer, R. M. Sharples

We report on the first results from a redshift survey of a flux-limited sample of X-ray clusters selected serendipitously from the ROSAT PSPC data archive. We spectroscopically confirm 15 clusters in the range 0.3 < z < 0.7, to a flux limit of ~ 3.9 x 10^-14 erg s^-1 cm^-2, over a survey area of 17.2 deg^2. The surface density of clusters in our survey is 2.

R. Jimenez, P. Padoan

We present new age and distance determinations for the Galactic Globular Clusters M55 and M5, using the luminosity function method (Jimenez & Padoan 1996, Padoan & Jimenez 1997). We find an age of $11.8 \pm 1.5$ Gyr for M55 and $11.1 \pm 0.7$ Gyr for M5. This confirms previous results (Jimenez et al. 1996, Sandquist et al. 1996) and allows to conclude that t

I. V. Artemova, G. S. Bisnovatyi-Kogan, G. Bjoernsson, I. D. Novikov

We consider the effects of advection and radial gradients of pressure and radial drift velocity on the structure of optically thick accretion disks. We concentrate our efforts on highly viscous disks, $α=1.0$, with large accretion rates. Contrary to disk models neglecting advection, we find that continuous solutions extending from the outer disk regions to t

Ramesh Narayan, Michael R. Garcia, Jeffrey E. McClintock

The defining characteristic of a black hole is that it possesses an event horizon through which matter and energy can fall in but from which nothing escapes. Soft X-ray transients (SXTs), a class of X-ray binaries, appear to confirm this fundamental property of black holes. SXTs that are thought to contain accreting black holes display a large variation of l

J. Hwang, H. Noh

Relativistic cosmological perturbation analyses can be made based on several different fundamental gauge conditions. In the pressureless limit the variables in certain gauge conditions show the correct Newtonian behaviors. We consider the general curvature and the cosmological constant in the background medium. The perturbed density in the comoving gauge, an

Taihei Yano, Naoteru Gouda

We investigate stability of the scale-invariant solutions of the BBGKY equations for two-point spatial correlation functions of the density fluctuations in the strongly non-linear regime. In the case that the background skewness of the velocity field is equal to 0, we found that there is no local instability in the strongly non-linear regime. The perturbatio

Stephane Paltani, Thierry J. -L. Courvoisier

We determine the variability-luminosity relationship of quasars and Seyfert galaxies in the rest frame of the objects using IUE spectra. We find that the variability decreases with the luminosity. An important part of the scatter in the relationship may be explained if one tries to estimate the uncertainties on the variability due to the sampling. We discuss

V. M. Lipunov, K. A. Postnov, M. E. Prokhorov

Study of gravitational-radiation induced merging rates of relativistic binary stars (double neutron stars; neutron star + black hole; double black holes) shows that the first-generation gravitational wave interferometers with an rms-sensitivity of $10^{-21}$ at frequency 100 Hz can detect 10-700 black hole and only $\sim 1$ neutron star coalescences in a 1-y

Theodore Simon, Wayne B. Landsman

We report the detection of N V 1239 A transition region emission in HST/GHRS spectra of the A7 V stars, Alpha Aql and Alpha Cep. Our observations provide the first direct evidence of 1-3 x 10^5 K material in the atmospheres of normal A-type stars. For both stars, and for the mid-A--type star Tau3 Eri, we also report the detection of chromospheric emission in

V. S. Vladimirov

On the basis of analysis on the adele ring of any algebraic numbers field (Tate&#39;s formula) a regularization for divergent adelic products of gamma- and beta-functions for all completions of this field are proposed, and corresponding regularized adelic formulas are obtained.

Cristopher Moore

Simulating a cellular automaton (CA) for t time-steps into the future requires t^2 serial computation steps or t parallel ones. However, certain CAs based on an Abelian group, such as addition mod 2, are termed ``linear&#39;&#39; because they obey a principle of superposition. This allows them to be predicted efficiently, in serial time O(t) or O(log t) in p

C. Neumann, R. Ubert, S. Freund, E. Floethmann

We present the first observations of cylindrical symmetry breaking in highly excited diamagnetic hydrogen with a small crossed electric field, and we give a semiclassical interpretation of this effect. As the small perpendicular electric field is added, the recurrence strengths of closed orbits decrease smoothly to a minimum, and revive again. This phenomeno

Han-Wen Huang

Hadronic annihilation decay rates of P-wave heavy quarkonia are given to next-to-leading order in both $α_s$ and $v^2$. They include ten nonperturbative parameters, which can be rigorously defined as the matrix elements of color-singlet and color-octet operators in NRQCD. We expect these papameters will be determined from lattice calculations in future.

Kiyoung Kim

Through a new interpretation of Special Theory of Relativity and with a model given for physical space, we can find a way to understand the basic principles of Quantum Mechanics consistently from Classical Theory. It is supposed that natural phenomena have a connection with intangible reality which cannot be measured directly. Furthermore, the intangible rea

C. Alexandrou, R. Rosenfelder, A. W. Schreiber

Nonperturbative polaron variational methods are applied, within the so-called particle or worldline representation of relativistic field theory, to study scattering in the context of the scalar Wick - Cutkosky model. Important features of the variational calculation are that it is a controlled approximation scheme valid for arbitrary coupling strengths, the

Horst Mueller

We study the phase transition of asymmetric hadronic matter to a quark-gluon plasma within the framework of a simple two-phase model. The analysis is performed in a system with two conserved charges (baryon number and isospin) using the stability conditions on the free energy, the conservation laws and Gibbs&#39; criteria for phase equilibrium. The EOS is ob

Andreas Baudisch

Alternating bilinear maps with few relations allow to define a combinatorial closure similarly as in [2]. For the $\aleph_0$-categorical case we show that this closure is part of the algebraic closure.

Mikhail Plyushchay

A universality of deformed Heisenberg algebra involving the reflection operator is revealed. It is shown that in addition to the well-known infinite-dimensional representations related to parabosons, the algebra has also finite-dimensional representations of the parafermionic nature. We demonstrate that finite-dimensional representations are representations

E. V. Gedalin

The probability of color tube fission that includes the tube surface small oscillation corrections is obtained with pre-exponential factor accuracy on the basis of previously constructed color tube model. Using these expressions the probability of the tube fission in $n$ point is obtained that is the basis for calculation of inclusive spectra of produced had

P. H. Damgaard, U. M. Heller, A. Krasnitz, P. Olesen

We discuss the confining and chiral-symmetry breaking properties of QCD with a large number of flavors $N_f$. In a Monte Carlo simulation of QCD with $N_f =16$ staggered fermions, we find clear evidence of a first order bulk phase transition which separates phases with broken and unbroken chiral symmetry. This is consistent with extrapolations of earlier stu

Yael Karshon

We define a moment map associated to a smooth torus action on a smooth manifold, without a two-form. We define cobordisms of such structures, allowing non compact manifolds as long as the moment maps are proper. We prove that a compact manifold with a torus action and a moment map is cobordant to the disjoint union of the normal bundles of the connected comp

T. H. Baker, P. J. Forrester

For the Gaussian and Laguerre random matrix ensembles, the probability density function (p.d.f.) for the linear statistic $\sum_{j=1}^N (x_j - <x>)$ is computed exactly and shown to satisfy a central limit theorem as $N \to \infty$. For the circular random matrix ensemble the p.d.f.&#39;s for the linear statistics ${1 \over 2} \sum_{j=1}^N (θ_j - π)$ and $-

O. Gunnarsson, S. C. Erwin, E. Koch, R. M. Martin

We show that hopping via the alkali atoms plays an important role for the t1u band of A4C60 (A=K, Rb), in strong contrast to A3C60. Thus the t1u band is broadened by more than 40 % by the presence of the alkali atoms. The difference between A4C60 and A3C60 is in particular due to the less symmetric location of the alkali atoms in A4C60.

F. Aryasetiawan, O. Gunnarsson, E. Koch, R. M. Martin

The Pauli paramagnetic susceptibility of A3C60 (A= K, Rb) compounds is calculated. A lattice quantum Monte Carlo method is applied to a multi-band Hubbard model, including the on-site Coulomb interaction U. It is found that the many-body enhancement of the susceptibility is of the order of a factor of three. This reconciles estimates of the density of states

A. A. Golubov, I. I. Mazin

We generalize Abrikosov-Gor&#39;kov solution of the problem of weakly coupled superconductor with impurities on the case of a multiband superconductor with arbitrary interband order parameter anisotropy, including interband sign reversal of the order parameter. The solution is given in terms of the effective (renormalized) coupling matrix and describes not o

C. B. Yang, X. Cai

The finite-size effects in critical phenomena of a thin film system are studied from a mean field (MF) approach with $ϕ^4$ model for second-order phase transition. The influence of boundary condition on the critical properties are emphasized. Scaling functions for relative free-energy and relative specific heat capacity are given.

J. E. Hibbard

The most active starbursts are found in galaxies with the highest IR luminosities, with peak star formation rates and efficiencies that are over an order of magnitude higher than in normal disk systems. These systems are almost exclusively on-going mergers. In this review I explore the conditions needed for interactions to experience such a phase by comparin

K. S. Stelle

We review the properties of classical p-brane solutions to supergravity theories, i.e. solutions that may be interpreted as Poincare-invariant hyperplanes in spacetime. Topics covered include the distinction between elementary/electric and solitonic/magnetic solutions, examples of singularity and global structure, relations between mass densities, charge den

Gungwon Kang

It has been known classically that a star with an ergoregion but no event horizon is unstable to the emission of scalar, electromagnetic and gravitational waves. This classical ergoregion instability is characterized by complex frequency modes. We show how to canonically quantize a neutral scalar field in the presence of such unstable modes by considering a

Omar Foda, Bernard Leclerc, Masato Okado, Jean-Yves Thibon

We review and motivate recently-observed relationships between exactly solvable lattice models and modular representations of Hecke algebras. Firstly, we describe how the set of $n$-regular partitions label both of the following classes of objects: 1. The spectrum of unrestricted solid-on-solid lattice models based on level-1 representations of the affine al

Omar Foda, Bernard Leclerc, Masato Okado, Jean-Yves Thibon

A special family of partitions occurs in two apparently unrelated contexts: the evaluation of 1-dimensional configuration sums of certain RSOS models, and the modular representation theory of symmetric groups or their Hecke algebras $H_m$. We provide an explanation of this coincidence by showing how the irreducible $H_m$-modules which remain irreducible unde

Douglas Singleton

Using the result that an electric charge - magnetic charge system carries an internal field angular momentum of $e g / 4 π$ we arrive at two restrictions on magnetic monopoles via the requirement of angular momentum quantization and/or conservation. First we show that magnetic charge should scale in the opposite way from electric charge. Second we show that

Paul O&#39;Hara

Bell&#39;s inequality has been traditionally used to explore the relationship between hidden variables and the Copenhagen interpretation of quantum mechanics. In this paper, another use is found. Bell&#39;s inequality is used to derive a coupling principle for elementary particles and to give a deeper understanding of baryonic structure. We also give a deriv

C. S. Kim

I first introduce the importance of measuring V_ub precisely. Then, from a theoretician&#39;s point of view, I review (a) past history, (b) present trials, and (c) possible future alternatives on measuring |V_ub| and/or |V_ub/V_cb|. As of my main topic, I introduce a model-independent method, which predicts Γ(B -> X_u l ν) / Γ(B -> X_c l ν) \equiv (γ_u / γ_c

Peter Aichelburg, Abhay Ashtekar

This pre-print contains the abstracts of seminars (including key references) presented at the ESI workshop on mathematical problems in quantum gravity held during July and August of 1996. Contributors include A. Ashtekar, J. Baez, F. Barbero, A. Barvinsky, F. Embacher, R. Gambini, D. Giulini, J. Halliwell, T. Jacobson, R. Loll, D. Marolf, K. Meissner, R. Mye

Roberto De Pietri

I discuss the role played by the spin-network basis and recoupling theory (in its graphical tangle-theoretic formulation) and their use for performing explicit calculations in loop quantum gravity. In particular, I show that recoupling theory allows the derivation of explicit expressions for the eingenvalues of the quantum volume operator. An important side

Omri Gat, Victor S. L&#39;vov, Itamar Procaccia

The anomalous scaling behavior of the n-th order correlation functions $F_n$ of the Kraichnan model of turbulent passive scalar advection is believed to be dominated by the homogeneous solutions (zero-modes) of the Kraichnan equation $\hat{B}_n F_n=0$. In this paper we present an extensive analysis of the simplest (non-trivial) case of n=3 in the isotropic s

Fred C. Adams, Gregory Laughlin

This paper outlines astrophysical issues related to the long term fate of the universe. We consider the evolution of planets, stars, stellar populations, galaxies, and the universe itself over time scales which greatly exceed the current age of the universe. (shortened version of abstract).

Jaan Einasto

We investigate the distribution of clusters of galaxies and determine the cluster correlation function and power spectrum. Clusters of galaxies located in rich superclusters with at least 8 members form a quasiregular network of superclusters and voids. The correlation function of clusters in rich superclusters is oscillating with a period of 120 Mpc (for Hu

Bert van Geemen, Aise Johan de Jong

The aim of this paper is to give an explicit expression for Hitchin&#39;s connection in the case of rank 2 bundles with trivial determinant over curves of genus 2. We recall the definition of this connection (which arose in Quantum Field Theory) and characterize it for families of genus two curves. We then consider a particular family (over a configuration s

R. Sekhar Chivukula

In these lectures, I present an introduction to the theory and phenomenology of dynamical electroweak symmetry breaking.

K. G. Boreskov, L. A. Kondratyuk, M. I. Krivoruchenko, J. H. Koch

The influence of nuclear matter on the properties of coherently produced resonances is discussed. It is shown that, in general, the mass distribution of resonance decay products has a two-component structure corresponding to decay outside and inside the nucleus. The first (narrow) component of the amplitude has a Breit-Wigner form determined by the vacuum va

E. J. Copeland, Richard Easther, David Wands

We study axion-dilaton cosmologies derived from the low-energy string effective action. We present the classical homogeneous Friedmann-Robertson-Walker solutions and derive the semi-classical perturbation spectra in the dilaton, axion and moduli fields in the pre-Big Bang scenario. By constructing the unique S-duality invariant field perturbations for the ax

Bodo Huckestein, Rochus Klesse

We performed numerical calculations of the local density of states (LDOS) at disorder induced localization-delocalization transitions. The LDOS defines a spatial measure for fixed energy and a spectral measure for fixed position. At the mobility edge both measures are multifractal and their generalized dimensions $D(q)$ and $\tilde{D}(q)$ are found to be pro