February 1996 arXiv papers — page 5

G. Squires, N. Kaiser, G. Fahlman, A. Babul

We report on the detection of dark matter in the cluster Abell 2390 using the weak gravitational distortion of background galaxies. We find that the cluster light and total mass distributions are quite similar over an angular scale of $\simeq 7^\prime \;(1 \Mpc$). The cluster galaxy and mass distributions are centered on the cluster cD galaxy and exhibit ell

Christian Y. Cardall, George M. Fuller

We examine the potential for a ``natural'' three-neutrino mixing scheme to satisfy available data and astrophysical arguments. By ``natural'' we mean no sterile neutrinos, and a neutrino mass hierarchy similar to that of the charged leptons. We seek to satisfy (or solve): 1. Accelerator and reactor neutrino oscillation constraints, including

Ravi K. Sheth, Bhuvnesh Jain

The correlation function xi(r) of matter in the non-linear regime is assumed to be determined by the density profiles rho(r) and the mass distribution n(M) of virialized halos. The Press--Schechter approach is used to compute n(M), and the stable clustering hypothesis is used to determine the density profiles of these Press--Schechter halos. Thus, the shape

Cheongho Han, Andrew Gould

A new type of gravitational microlensing experiment toward a field where stars are not resolved is being developed observationally and theoretically: pixel lensing. When the experiment is carried out toward the M31 bulge area, events may be produced both by Massive Compact Halo Objects (MACHOs) in our Galactic halo and by lenses in M31. We estimate that $\si

Anirvan M. Sengupta, Yong Baek Kim

We consider the single channel Kondo problem with the Kondo coupling between a spin $S$ impurity and conduction electrons with spin $j$. These problems arise as multicritical points in the parameter spaces of two- and higher-level tunneling systems, and some impurity models of heavy fermion compounds. In contrast to the previous Bethe-anstaz conjectures, it

Hangmo Yi, C. L. Kane

We study the motion of a particle in a periodic potential with Ohmic dissipation. In $D=1$ dimension it is well known that there are two phases depending on the dissipation: a localized phase with zero temperature mobility $μ=0$ and a fully coherent phase with $μ$ unaffected by the periodic potential. For $D>1$, we find that this is also the case for a Brava

R. A. C. Croft, E. Gaztanaga

We present a method for reconstructing cosmological densityn for and velocity fields using the Lagrangian Zel'dovich formalism. . The method involves finding the least action solution for straight line particle paths in an evolving density field. Our starting point is the final, evolved density , so that we are in effect carrying out the standard Zel&#39

Weiping Li

We define an integer graded symplectic Floer cohomology and a spectral sequence which are new invariants for monotone Lagrangian sub-manifolds and exact isotopies. Such an integer graded Floer cohomology is an integral lifting of the usual Floer-Oh cohomology with $Z_{\Si (L)}$ grading. As one of applications of the spectral sequence, we offer an affirmative

Andrei Okounkov

We prove Capelli type identities which involve the whole universal enveloping algebra $U(gl(n))$ and matrix elements of irreducible representations of the symmetric group. These identities generalize higher Capelli identities for the center of $U(gl(n))$ introduced in the author's paper \cite{Ok}. The main role in the proof play the Jucis-Murphy elements

E. Battaner, E. Florido, J. Jimenez-Vicente

We consider that no mean magnetic field exists during this epoch, but that there is a mean magnetic energy associated with large-scale magnetic inhomogeneities. We study the evolution of these inhomogeneities and their influence on the large scale density structure, by introducing linear perturbations in Maxwell equations, the conservation of momentum-energy

A. Silverberg, Yu. G. Zarhin

We study semistable reduction and torsion points of abelian varieties. In particular, we give necessary and sufficient conditions for an abelian variety to have semistable reduction. We also study Néron models of abelian varieties with potentially good reduction and torsion points of small order. We study some invariants that measure the extent to which an a

Jan Ambjorn, Piotr Bialas, Jerzy Jurkiewicz

A recently proposed renormalization group technique, based on the hierarchical structures present in theories with fluctuating geometry, is implemented in the model of branched polymers. The renormalization group equations can be solved analytically, and the flow in coupling constant space can be determined.

Hanqing Zheng

We study the properties of heavy fermions in the vector-like representation of the electro-weak gauge group $SU(2)_W\times U(1)_Y$ with Yukawa couplings to the standard model (SM) Higgs boson. Using the renormalization group analysis, we discuss their effects on the vacuum stability and the triviality bound on the Higgs self-coupling, within the context of t

Boris V. Komberg, Andrey V. Kravtsov, Vladimir N. Lukash

Recently, it was suggested that large concentrations or groups of quasars may trace sites of enhanced matter density at medium and high redshifts analogous to how galaxy clusters trace them in nearby space. We have checked existing quasar data for the presence of such groups. Large Quasar Groups (LQGs) were identified using a well-known cluster analysis tech

Gilles Brassard

Classical and quantum information are very different. Together they can perform feats that neither could achieve alone, such as quantum computing, quantum cryptography and quantum teleportation. Some of the applications range from helping to preventing spies from reading private communications. Among the tools that will facilitate their implementation, we no

Andrei Okounkov

We consider remarkable central elements of the universal enveloping algebra of the general linear algebra which we call quantum immanants. We express them in terms of generators $E_{ij}$ and as differential operators on the space of matrices. These expressions are a direct generalization of the classical Capelli identities. They result in many nontrivial pro

Antun Milas

Let $V_1 \otimes V_2$ be a tensor product of VOAs. Using Zhu theory we discuss the theory of representations of V (associative algebra, modules and fusion rules). We prove that this theory is more or less the same as representation theory of tensor product of the associative algebras.

Jose L. Cortes, Mikhail S. Plyushchay

It is demonstrated that the recently proposed pseudoclassical model for Weyl particles [1] (D.M. Gitman, A.E. Goncalves and I.V. Tyutin, Phys. Rev. D 50 (1994) 5439) is classically inconsistent. A possible way of removing the classical inconsistency of the model is proposed.

V. P. Frolov, W. Israel, S. N. Solodukhin

Quantum corrections are studied for a charged black hole in a two-dimensional model obtained by spherisymmetric reduction of the 4D Einstein-Maxwell theory. The classical (tree-level) thermodynamics is re-formulated in the framework of the off-shell approach, considering systems at arbitrary temperature. This implies a conical singularity at the horizon and

Enrico Meggiolaro

In this paper we consider some analytic properties of the high--energy quark--quark scattering amplitude, which, as is well known, can be described by the expectation value of two lightlike Wilson lines, running along the classical trajectories of the two colliding particles. We shall prove that the expectation value of two infinite Wilson lines, forming a c

M. Martellini, K. Yoshida, M. Spreafico

We analyze the problems with the so called gauge invariant quantization of the anomalous gauge field theories originary due to Faddeev and Shatashvili (FS). Our analysis bring to a generalization of FS method which allows to construct a series of classically equivalent theories which are non equivalent at quantum level. We prove that these classical theories

Sergio Ferrara, Ramzi R. Khuri, Ruben Minasian

We compactify $M$-theory on a Calabi-Yau manifold to five dimensions by wrapping the membrane and fivebrane solitons of the eleven-dimensional supergravity limit around Calabi-Yau two-cycles and four-cycles respectively. We identify the perturbative and non-perturbative BPS states thus obtained with those of heterotic string theory compactified on $K3\times

Paolo Furlan, Ludmil K. Hadjiivanov, Ivan T. Todorov

Decoupling the chiral dynamics in the canonical approach to the WZNW model requires an extended phase space that includes left and right monodromy variables. Earlier work on the subject, which traced back the quantum qroup symmetry of the model to the Lie-Poisson symmetry of the chiral symplectic form, left some open questions: - How to reconcile the monodro

M. Yu. Kuchiev

The new phase of a gauge theory in which the instantons are ``polarized'', i.e. have the preferred orientation is discussed. A class of gauge theories with the specific condensates of the scalar fields is considered. In these models there exists an interaction between instantons resulting from one-fermion loop correction. The interaction makes the id

E. Sezgin

The well known N=2 string theory describes self-dual gravity, as was shown by Ooguri and Vafa sometime ago. In search of a variant of this theory which would describe self-dual supergravity in 2+2 dimensions, we have constructed two new N=2 strings theories in which the target space is a superspace. Both theories contain massless scalar and spinor fields in

D. Han, Y. S. Kim

The quark model and the parton model are known to be two different manifestations of the same covariant entity. However, the interaction amplitudes of partons are incoherent while they are coherent in the quark model. According to Feynman, this is due to the dilation of the interaction time among the quarks. We present a quantitative analysis of this time-di

A. Djouadi, V. Driesen, C. Junger

We analyse the loop induced production of Higgs boson pairs at future high--energy $e^+e^-$ colliders, both in the Standard Model and in its minimal supersymmetric extension. The cross sections for Standard Model Higgs pair production through $W/Z$ boson loops, $\ee \ra H^0 H^0$, are rather small but the process could be visible for high enough luminosities,

D. Bardin, D. Lehner, A. Leike, T. Riemann

We give a short review of the results for four fermion production, which have been obtained by the semi-analytical approach. The angular degrees of freedom (typically five or more) are integrated over analytically while the integrations over invariant fermion pair masses (typically two or more) remain to be performed by numerical methods. In addition to doub

Michio Hashimoto

We introduce isospin breaking terms as well as (SU(3)) breaking terms to the anomalous (VVP) coupling in the hidden local symmetry scheme without affecting the low energy theorem on the processes such as (π\to 2 γ) and (γ\to 3π). It is shown that the predictions from these terms coincide successfully with all the experimental data of anomalous decays. It is

Takahiro Tanaka, Yasushi Mino, Misao Sasaki, Masaru Shibata

Using the Teukolsky and Sasaki-Nakamura formalisms for the perterbations around a Kerr black hole, we calculate the energy flux of gravitational waves induced by a {\it spinning} particle of mass $μ$ and spin $S$ moving in circular orbits near the equatorial plain of a rotating black hole of mass $M (\gg μ)$ and spin $Ma$. The calculations are performed by u

Enrique Diez, Angel Sanchez, Francisco Dominguez-Adame

We introduce a model of a nonlinear double-barrier structure, to describe in a simple way the effects of electron-electron scattering while remaining analytically tractable. The model is based on a generalized effective-mass equation where a nonlinear local field interaction is introduced to account for those inelastic scattering phenomena. Resonance peaks s

A. D. Rutenberg

We find spatial anisotropy in the asymptotic correlations of two-dimensional Ising models under non-equilibrium phase-ordering. Anisotropy is seen for critical and off-critical quenches and both conserved and non-conserved dynamics. We argue that spatial anisotropy is generic for scalar systems (including Potts models) with an anisotropic surface tension. Co

Carsten Peterson, Ola Sommelius, Bo Söderberg

We consider the thermodynamics of a uniformly charged polyelectrolyte with harmonic bonds. For such a system there is at high temperatures an approximate scaling of global properties like the end-to-end distance and the interaction energy with the chain-length divided by the temperature. This scaling is broken at low temperatures by the ultraviolet divergenc

Gregory L. Eyink

We continue a previous work in which {\em a priori} estimates were derived on subgrid stress and subgrid flux for filtering schemes used in the turbulence modelling method of Large-Eddy Simulation (LES). The estimates were derived there as rigorous consequences of the exact subgrid stress formulae from Navier-Stokes equations under the conditions assumed for

Gregory L. Eyink

We establish and discuss {\em a priori} estimates on subgrid stress and subgrid flux for filtering schemes used in the turbulence modelling method of Large-Eddy Simulation (LES). Our estimates are derived as rigorous consequences of the exact subgrid stress formulae from Navier-Stokes equations under realistic conditions for inertial-range velocity fields, t

Carl E. Carlson, Eric J. Lowenstein

We study the possibility that galactic rotation curves can be explained by a gravitational potential that contains a linear term as well as a Newtonian one. This hypothesis, suggested by conformal gravity, does allow good fits to the galactic rotation curves of the galaxies we study, which have a wide range of luminosities. However, the universality one migh

J. E. Beckman, R. F. Peletier, J. H. Knapen, R. L. M. Corradi

We have measured the radial brightness distributions in the disks of three nearby face-on spirals: M 51, NGC 3631, and NGC 4321 (M 100) in the photometric bands B through I, with the addition of the K band for M 51 only. The measurements were made by averaging azimuthally, in three modes, the two-dimensional surface brightness over the disks in photometric i

Rien van de Weygaert, Tjeerd S. van Albada

The cosmological case for a next generation radio observatory, the Square Kilometer Array, is discussed and reviewed. An instrument like the SKA would be able to measure galaxy redshifts of normal late-type galaxies, via the 21 cm line of HI, out to redshifts of $\sim 3$. Not only would such very deep redshift surveys enable us to map the large scale galaxy

Edward W. Kolb, Antonio Riotto

In first-order inflation a phase transition is completed by the collisions of expanding true-vacuum bubbles. If bubble collisions produce large numbers of soft scalar particles carrying quantum numbers associated with a spontaneously broken symmetry, then symmetry restoration may occur in a ``pre-heating'' phase in a manner similar to symmetry restor

Philip D. Mannheim, Jan Kmetko

We continue our study of the astrophysical implications of the linear potential $V(r)=-βc^2/r+γc^2 r/2$ associated with fundamental gravitational sources in the conformal invariant fourth order theory of gravity which has recently been advanced by Mannheim and Kazanas as a candidate alternative to the standard second order Einstein theory. We provide fitting

Antoine Labeyrie

In the recent years, interferometric arrays of optical telescopes have reached sizes of the order of 100m, but they have yet to produce high-resolution images. The analysis of image formation now shows that such images are obtainable directly in the recombined focal plane, if there are enough telescopes. Resolved images of extra-solar planets are in principl

Alina-Catalina Donea, Peter L. Biermann

The UV continuum spectrum of quasars and AGN is assumed to originate from an accreting disk surrounding a massive rotating black hole. We discuss the structure and emission spectra of a disk which drives a powerful jet. Due to the large efficiency of extracting energy from the accreting matter in the inner part of the disk close to the massive object, all th

Vincent R. Eke, Shaun Cole, Carlos S. Frenk, Julio F. Navarro

The correlation function of galaxy clusters has often been used as a test of cosmological models. A number of assumptions are implicit in the comparison of theoretical expectations to data. Here we use an ensemble of ten large N-body simulations of the standard cold dark matter cosmology to investigate how cluster selection criteria and other uncertain facto

R. F. Peletier, M. Balcells

We compare optical and near-infrared colors of disks and bulges in a diameter-limited sample of inclined, bright, nearby, early-type spirals. Color profiles along wedge apertures at 15 degree from the major axis and on the minor axis on the side of the galaxy opposite to the dust lane are used to assign nominal colors for the inner disks (at 2 scale length)

Edwin R. Karat, Michael B. Schulz

We discuss the Hamiltonian for a nonrelativistic electron with spin in the presence of an abelian magnetic monopole and note that it is not self-adjoint in the lowest two angular momentum modes. We then use von Neumann's theory of self-adjoint extensions to construct a self-adjoint operator with the same functional form. In general, this operator will ha

Donald Marolf

A set of models is considered which, in a certain sense, interpolates between 1+1 free quantum field theories on topologically distinct backgrounds. The intermediate models may be termed free quantum field theories, though they are certainly not local. Their ground state energies are computed and shown to be finite. The possible relevance to changing spaceti

Peter G. Casazza, Niels Jorgen Nielsen

In this paper we investigate a Gaussian average property of Banach spaces. This property is weaker than the Gordon Lewis property but closely related to this and other unconditional structures. It is also shown that this property implies that certain Hilbert space valued operators defined on subspaces of the given space can be extended.

Douglas Singleton

Three dyon solutions to the SU(2) Yang-Mills-Higgs system are presented. These solutions are obtained from the BPS dyon by allowing the gauge fields to be complex, or by letting the free parameter of the BPS solution become imaginary. In all cases however the physically measurable quantities connected with these new solutions are entirely real. Although the

G. Aldazabal, A. Font, L. E. Ibanez, F. Quevedo

We consider $E_8\times E_8$ heterotic compactifications on $K3$ and $K3\times T^2$. The idea of heterotic/heterotic duality in $D=6$ has difficulties for generic compactifications since for large dilaton values some gauge groups acquire negative kinetic terms. Recently Duff, Minasian and Witten (DMW) suggested a solution to this problem which only works if t

M. Gasperini, G. Veneziano

In a Wheeler-de Witt approach to quantum string cosmology, the present state of the Universe arises from the scattering and reflection of the wave function representing the initial string vacuum in superspace. This scenario is described and compared with the more conventional quantum cosmology picture, in which the birth of the Universe is represented as a p

Pran Nath

We construct a class of textured supergravity unified SU(5) models using Planck scale corrections. We show that the texture constraints in the Higgs doublet sector are insufficient in general to fully determine the textures in the Higgs triplet sector. A classification of textured minimal parameter models is given and their Higgs triplet textures computed un

Reto Eggenschwiler, David Scialom, Norbert Straumann

We study the coupled Einstein-Yang-Mills-Dilaton (EYMD) equations for a Fried\-mann-Le\-mai\-tre universe with constant curvature $k=1$. Our detailed analysis is restricted to the case where the dilaton potential and the cosmological constant vanish. Also assuming a static gauge field, we present analytical and numerical results on the behavior of solutions

Robert M. Losee

Knowledge of window style, content, location and grammatical structure may be used to classify documents as originating within a particular discipline or may be used to place a document on a theory versus practice spectrum. This distinction is also studied here using the type-token ratio to differentiate between sublanguages. The statistical significance of

Tom Theuns, Henri Boffin, Alain Jorissen

Smoothed particle hydrodynamics (SPH) is used to estimate accretion rates of mass, linear and angular momentum in a binary system where one component undergoes mass loss through a wind. Physical parameters are chosen such as to model the alleged binary precursors of barium stars, whose chemical peculiarities are believed to result from the accretion of the w

Ali Mostafazadeh

The scattering of free particles constrained to move on a cylindrically symmetric curved surface is studied. The nontrivial geometry of the space contributes to the scattering cross section through the kinetic as well as a possible scalar curvature term in the quantum Hamiltonian. The coefficient of the latter term is known to be related to the factor orderi

T. Rauscher, G. Raimann

The reactions $^{10}$B(p,$α$)$^{7}$Be and $^{11}$B(p,$α$)$^{8}$Be are studied at thermonuclear energies using DWBA calculations. For both reactions, transitions to the ground states and first excited states are investigated. In the case of $^{10}$B(p,$α$)$^{7}$Be, a resonance at $E_{Res}=10$ keV can be consistently described in the potential model, thereby a

Amand Faessler, A. Sibirtsev, K. Tsushima

We study the $Δ$-excitation in $\overline{p}d$ annihilation at rest. The invariant spectra of the $π^+p$ and $π^-p$ systems selecting the protons with momenta above 400 MeV/c are analyzed. The calculations reproduces reasonably the experimental data.

G. Bimonte, A. Stern, P. Vitale

We reformulate the Hamiltonian approach to lattice gauge theories such that, at the classical level, the gauge group does not act canonically, but instead as a Poisson-Lie group. At the quantum level, it then gets promoted to a quantum group gauge symmetry. The theory depends on two parameters - the deformation parameter $λ$ and the lattice spacing $a$. We s

Gia Dvali, K. Tamvakis

We analyse the high temperature behaviour of softly broken supersymmetric theories taking into account the role played by effective non-renormalizable terms generated by the decoupling of superheavy degrees of freedom or the Planck scale physics. It turns out that discrete or continuous symmetries, spontaneously broken at intermediate scales, may never be re

Michael Gronau, Jonathan L. Rosner

Certain hadronic two-body decays of $B$ mesons are dominated by penguin diagrams. The ratios of rates for several such decays, including $Γ(B^0 \to \overline{K}^{*0} K^0)/Γ(B^0 \to ϕK^0)$, $Γ(B^0 \to \overline{K}^{*0} K^{*0})/Γ(B^0 \to ϕK^{*0})$, $Γ(B^+ \to \overline{K}^{*0} K^+)$ $/Γ(B^+ \to ϕK^+)$, and $Γ(B^+ \to \overline{K}^{*0} K^{*+})/Γ(B^+ \to ϕK^{*+}

Glennys R. Farrar

When the gluino is light and long lived, missing energy is a poor signature for both squarks and gluinos. Instead, squark pair production leads to events with $\ge 4$ jets. If a chargino can decay to squark and quark, missing energy is also a poor signature for the chargino. Properties of 4-jet events originating from squarks are discussed. ALEPH's preli

Jerzy Lewandowski

The aim of this letter is to indicate the differences between the Rovelli-Smolin quantum volume operator and other quantum volume operators existing in the literature. The formulas for the operators are written in a unifying notation of the graph projective framework. It is clarified whose results apply to which operators and why.

T. Rauscher, F. -K. Thielemann, K. -L. Kratz

The prediction of cross sections for nuclei far off stability is crucial in the field of nuclear astrophysics. In recent calculations the nuclear level density -- as an important ingredient to the statistical model (Hauser-Feshbach) -- has shown the highest uncertainties. We present a global parametrization of nuclear level densities based on the back-shifte

Antonaldo Diaferio, Margaret J. Geller

The redshift-space correlation function $ξ_s$ for projected galaxy separations $\simless 1h^{-1}$ Mpc can be expressed as the convolution of the real-space correlation function with the galaxy pairwise velocity distribution function (PVDF). An exponential PVDF yields the best fit to the $ξ_s$ measured from galaxy samples of different redshift surveys. We sho

C. M. Baugh, S. Cole, C. S. Frenk

We present a model for the broad morphological distinction between the disk and spheroidal components of galaxies. Elaborating on the hierarchical clustering scheme of galaxy formation proposed by Cole et al., we assume that galaxies form stars quiescently in a disk until they are disrupted into a spheroidal configuration by mergers. We calculate formation a

Victor V. Batyrev, Yuri Tschinkel

We consider some families of smooth Fano hypersurfaces $X_{n+2}$ in ${\bf P}^{n+2} \times {\bf P}^3$ given by a homogeneous polynomial of bidegree $(1,3)$. For these varieties we obtain lower bounds for the number of $F$-rational points of bounded anticanonical height in arbitrary nonempty Zariski open subset $U \subset X_{n+2}$. These bounds contradict prev

Chong-Sun Chu, Pei-Ming Ho, Bruno Zumino

We consider the problem of constructing the fully gauged effective action in $2n$-dimensional space-time for Nambu-Goldstone bosons valued in a homogeneous space $G/H$, with the requirement that the action be a solution of the anomalous Ward identity and be invariant under the gauge transformations of $H$. We show that this can be done whenever the homotopy

Jaroslav Fabian

A semi-empirical model of the infrared (IR) spectrum of the C$_{60}$ molecule is proposed. The weak IR-active modes seen experimentally in a C$_{60}$ crystalline sample are argued to be combination modes caused by anharmonicity. The origin of these 2-mode excitations can be either mechanical (anharmonic interatomic forces) or electrical (nonlinear dipole-mom

S. A. Dias, M. B. Silva Neto

We study bosonization ambiguities in two dimensional quantum electrodynamics in the presence and in the absence of topologically charged gauge fields. The computation of fermionic correlation functions suggests that ambiguities may be absent in nontrivial topologies, provided that we do not allow changes of sector as we evaluate functional integrals. This wo

M. Bordag, K. Kirsten, J. S. Dowker

We consider zeta functions and heat-kernel expansions on the bounded, generalized cone in arbitrary dimensions using an improved calculational technique. The specific case of a global monopole is analysed in detail and some restrictions thereby placed on the $A_{5/2}$ coefficient. The computation of functional determinants is also addressed. General formulas

Justino Martinez

In this paper we introduce a new method to study the influence of thermal conduction and viscous processes in anisotropic gravitational collapse. To this end we employ the HJR method to solve the Einstein equations. The Maxwell-Cattaneo type transport equations are used to find the temperature and bulk and shear viscous pressures. Under some conditions Maxwe

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

We present first results for $B_c$ spectroscopy using Lattice Non-Relativistic QCD (NRQCD). For the NRQCD action the leading order spin-dependent and next to leading order spin-independent interactions have been included with tadpole-improved coefficients. We use multi-exponential fits to multiple correlation functions to extract ground and excited $S$ state

Hisamitsu Mukaida, Yujiro Shimada

We obtain effective potential of $O(N)$-symmetric $ϕ^4$ theory for large $N$ starting with a finite lattice system and taking the thermodynamic limit with great care. In the thermodynamic limit, it is globally real-valued and convex in both the symmetric and the broken phases. In particular, it has a flat bottom in the broken phase. Taking the continuum limi

N. G. Uraltsev

The constituent picture of hadrons implies certain quantum mechanical inequalities which must hold in the potential models. Basing on this qualitative consideration I argue that it is not easy to increase significantly the scale of the flavor-dependent 1/m_b^3 effects within the heavy quark expansion preserving the conventional constituent picture of heavy f

Bernard Leclerc, Jean-Yves Thibon

We define a canonical basis of the $q$-deformed Fock space representation of the affine Lie algebra $\glchap_n$. We conjecture that the entries of the transition matrix between this basis and the natural basis of the Fock space are $q$-analogues of decomposition numbers of the $v$-Schur algebras for $v$ specialized to a $n$th root of unity.

A. Duncan, S. Pernice

The properties of a generalized version of the Borel Transform in infrared unstable theories with dynamical mass generation are studied. The reconstruction of the nonperturbative structure is unambiguous in this version. Various methods for extracting the singularity structure of the Borel Transform for lattice formulations of such theories are explored, and

P. A. Horvathy, J. C. Yera

A Bäcklund transformation yielding the static non-relativistic Chern-Simons vortices of Jackiw and Pi is presented.

Serdar Nergiz, Cihan Saclioglu

The Seiberg--Witten equations, when dimensionally reduced to $\bf R^{2}\mit$, naturally yield the Liouville equation, whose solutions are parametrized by an arbitrary analytic function $g(z)$. The magnetic flux $Φ$ is the integral of a singular Kaehler form involving $g(z)$; for an appropriate choice of $g(z)$ , $N$ coaxial or separated vortex configurations

M. Gasperini, J. Maharana, G. Veneziano

We write an O(d,d)-covariant Wheeler-De Witt equation in the ($d^2+1$)-dimensional minisuperspace of low-energy cosmological string backgrounds. We discuss explicit examples of transitions between two duality-related cosmological phases, and we find a finite quantum transition probability even when the two phases are classically separated by a curvature sing

P. I. Krastev, S. T. Petcov, L. Qiuyu

We study the stability of the two--neutrino MSW solution of the solar neutrino problem, corresponding to solar $ν_e$ transitions into sterile neutrino, $ν_e \rightarrow ν_s$, with respect to changes of the total fluxes of $^{8}$B and $^{7}$Be neutrinos, $Φ_{\rm B}$ and $Φ_{\rm Be}$. For any value of $Φ_{\rm Be}$ from the interval $0.7Φ^{\rm BP}_{\rm Be}\leq

Thomas G. Rizzo

We extend our previous analysis of the sensitivity of the energy dependence of the polarization asymmetry in $\gamma e \to W\nu$ to the possible existence of anomalous trilinear gauge couplings to the $\gamma e \to Ze$ case. We find that by combining the constraints imposed by both the energy dependence of the total cross section and polarization asymmetry,

Myron Bander

Possible spin-3/2 quark resonances would have a significant effect on high E$_{\mbox{\rm t}}$ jet production through their contribution to the subprocess $q+{\bar q}\rightarrow g+g$. Such enhancements are compared to a, recently reported, anomaly in inclusive jet production at the CDF detector.

K. Sridhar

The analyses of large transverse momentum charmonium production at the Tevatron have shown that fragmentation of gluons is an important production mechanism. We study large-$p_T$ charmonium production in $pp$ collisions at the LHC, and find that due to the copious gluon production at this energy, the gluon fragmentation contribution completely overwhelms the

P. Chiappetta, F. M. Renard, C. Verzegnassi

We consider the virtual signals of a $Z'$ of very general type in the process $e^+e^-\to W^+W^-$ at a future linear $e^+e^-$ collider of 2000 GeV c.m. energy ($LC2000$). We show that possible deviations from the SM predictions in this channel are related to similar deviations in the purely leptonic one in a way that is only characteristic of this $Z'

J. Layssac, G. Montagna, O. Nicrosini, F. Piccinini

We consider the possibility that one extra $Z\equiv Z'$ exists with a mass of more then two TeV and fermion couplings that do not violate (charged) lepton universality. We show that, in such a situation, a functional relationship is generated between the \underline{deviations} from the SM values of three leptonic observables of two-fermion production at

Z. G. Berezhiani

We discuss the physics of the mirror (shadow) world which is completely analogous to the visible one except that its `weak' scale is larger by one or two orders of magnitude than the weak scale in the standard model. The mirror neutrinos can mix the ordinary ones through the Planck scale induced higher order operators, which can help to reconcile the pre

Zurab Berezhiani

The problem of fermion masses and mixings is discussed in the context of supersymmetric grand unification theories. Some predictive frameworks based on the $SU(5)$, $SO(10)$ and $SU(6)$ models are reviewed. [Based on lectures delivered at the ICTP Summer School on `High Energy Physics and Cosmology', Trieste, Italy, 3-28 July 1995 (to appear on Proceedin

Karim Ait Moussa, Gérard Clément

We construct two classes of exact solutions to the field equations of topologically massive electrodynamics coupled to topologically massive gravity in 2 + 1 dimensions. The self-dual stationary solutions of the first class are horizonless, asymptotic to the extreme BTZ black-hole metric, and regular for a suitable parameter domain. The diagonal solutions of

S. N. Behera, Umesh. A. Salian, Haranath Ghosh

The common features in the Raman data of high temperature superconductors: (the cuprates, bismathates, alkali doped fullerides and some organic superconductors), are analyzed. It was shown that qualitative understanding of the data can be achieved in terms of non-Fermi liquid models for their normal state, with appropiate bag mechanisms for the superconducti

A. Greco, A. Dobry

We have used an exact diagonalization technique to study the stability of the $t-J$-Holstein and Hubbard-Holstein models under the influence of the electron-phonon interaction. Previous results have been obtained using frozen-phonon technique or introducing only a few dynamical phonon modes due to the large Hilbert space. To check these results we have done

P. Ao

Based on a recent work (Thouless, Ao, and Niu, Transverse force on a quantized vortex in a superfluid) I show that the spectral or momentum flow due to a moving vortex is identical to the phase slippage process discussed by Josephson and Anderson. I also show that the force due to the spectral flow is the reaction force of the Magnus force, and that the two

James T. Liu, D. F. Wang

We generalize the SU(2|2) supersymmetric extended Hubbard model of 1/r2 interaction to the SU(m|n) supersymmetric case. Integrable models may be defined on both uniform lattice and non-uniform one dimensional lattices. We study both cases in detail and present the ground state wavefunctions and energy spectra of these models.

Bosiljka Tadic, Ramakrishna Ramaswamy

We study a directed coupled map lattice model in two dimensions, with two degrees of freedom associated with each lattice site. The two freedoms are coupled at a fraction $c$ of lattice bonds acting as quenched random defects. In the case of conservative dynamics, at any concentration of defects the system reaches a self-organized critical state with univers

Lloyd C. L. Hollenberg, N. S. Witte

A closed form expression for the ground state energy density of the general extensive many-body problem is given in terms of the Lanczos tri-diagonal form of the Hamiltonian. Given the general expressions of the diagonal and off-diagonal elements of the Hamiltonian Lanczos matrix, $α_n(N)$ and $β_n(N)$, asymptotic forms $α(z)$ and $β(z)$ can be defined in te

Peter S. Conti, Claus Leitherer, William D. Vacca

We have obtained a Hubble Space Telescope ultraviolet image and spectrum of the nearby Wolf-Rayet galaxy NGC 1741. The spatial morphology from the Faint Object Camera image is dominated by two main starburst centers, each being about 100 times as luminous as 30 Doradus. Both starburst centers are composed of several intense knots of recent star formation. A

M. A. G. Maia, J. A. Suzuki, L. N. da Costa, C. N. A. Willmer

This paper contains a list of new AGN candidates identified from the examination of 3500 optical spectra contained in the database of the Southern Sky Redshift Survey Extension (SSRS2). The classification of galaxies was done using standard diagnostics and a total of (5) Seyfert 1, (12) Seyfert 2 and (10) LINERs were found. We also present a list of 60 galax

HongGuang BI, Li-Zhi FANG

We have developed a method for calculating the two-point correlation function of nonlinearly evolved mass and collapsed halos in the Press-Schechter formalism. The nonlinear gravitational interaction is treated as the sum of various individual spherical top-hat clustering. Because no collapsed halo of mass M can exist in initial regions (or top-hat spheres)

H. Ebeling, W. Voges, H. Boehringer, A. C. Edge

We present an essentially complete, all-sky, X-ray flux limited sample of 242 Abell clusters of galaxies (six of which are double) compiled from ROSAT All-Sky Survey data. Our sample is uncontaminated in the sense that systems featuring prominent X-ray point sources such as AGN or foreground stars have been removed. The sample is limited to high Galactic lat

David Merritt, Monica Valluri

We investigate the timescales for stochasticity and chaotic mixing in a family of triaxial potentials that mimic the distribution of light in elliptical galaxies. Some of the models include central point masses designed to represent nuclear black holes. Most of the boxlike orbits are found to be stochastic, with mean Liapunov times that are 3-6 times the per

Alexandros A. Kehagias, Andre Lukas

We analyze the quantum cosmology of one--loop string effective models which exhibit an $O(d,d)$ symmetry. It is shown that due to the large symmetry of these models the Wheeler--de Witt equation can completely be solved. As a result, we find a basis of solutions with well defined transformation properties under $O(d,d)$ and under scale factor duality in part