May 1997 arXiv papers — page 15

Shibaji Roy

It has been shown recently that the toroidally compactified type IIB string effective action possesses an SL(2, R) invariance as a consequence of the corresponding symmetry in ten dimensions when the self-dual five-form field strength is set to zero. By working in the string frame we clarify how a Z$_2$ subgroup of this SL(2, R) group responsible for produci

David Augier, Didier Poilblanc

Properties of low-dimensional spin-Peierls systems are described by using a one dimensional S=1/2 antiferromagnetic Heisenberg chain linearly coupled to a single phonon mode of wave vector pi (whose contribution is expected to be dominant). By exact diagonalizations of small rings with up to 24 sites supplemented by a finite size scaling analysis, static and

A. Pérez Martínez, A. Amézaga Hechavarría, D. Oliva Agüero, H. Pérez Rojas

We compute the dispersion curves for neutrinos propagating in an extremely dense electroweak plasma, in the presence of very strong magnetic fields of order $B \le M_W^2/e$. The neutrino self-energy is calculated in the one-loop approximation. We consider only contributions of the first Landau level to the propagator of the W-bosons, and distinguish between

M. Payami, N. Nafari

In this paper, we have considered the mechanical stability of a jellium system in the presence of spin degrees of freedom and have generalized the stabilized jellium model, introduced by J. P. Perdew, H. Q. Tran, and E. D. Smith [Phys. Rev. B42, 11627 (1990)], to a spin-polarized case. By applying this generalization to metal clusters (Al, Ga, Li, Na, K, Cs)

J. R. Mureika

A quick and fun investigation into the effects of correcting for wind assistance/resistance and drag on 100m sprint performances. Considered are World 100m rankings, as well as Canadian rankings

C. -H. Lee, T. T. S. Kuo, G. Q. Li, G. E. Brown

The momentum dependence of the empirical scalar and vector potentials needed for describing relativistic heavy-ion collisions at 1 GeV/nucleon is compared with that derived from self-consistent Dirac-Brueckner calculations using the Bonn-A potential. Our calculated scalar and vector potentials exhibit a weak momentum dependence and their magnitudes decrease

L. Ya. Glozman, Z. Papp, W. Plessas, K. Varga

We study the performance of some recent potential models suggested as effective interactions between constituent quarks. In particular, we address constituent quark models for baryons with hybrid Q-Q interactions stemming from one-gluon plus meson exchanges. Upon recalculating two of such models we find them to fail in describing the N and Δspectra. Our calc

A. Metz, D. Drechsel

In a previous paper virtual Compton scattering off the nucleon has been investigated in the one-loop approximation of the linear sigma model in order to determine the 3 scalar generalized polarizabilities. We have now extended this work and calculated the 7 vector polarizabilities showing up in the spin-dependent amplitude of virtual Compton scattering. The

Jörg Winkelmann

We study flat vector bundles over complex parallelizable manifolds.

Jörg Winkelmann

We study the rigidity questions and the Albanese Variety for Complex Parallelizable Manifolds. Both are related to the study of the cohomology group $H^1(X,\mathcal O)$. In particular we show that a compact complex parallelizable manifold is rigid iff $b_1(X)=0$ iff Alb$(X)=\{e\}$ iff $H^1(X,\mathcal O)=0$.

David W. Catlin, John P. D'Angelo

In this paper we continue our study of a complex variables version of Hilbert's seventeenth problem by generalizing some of the results from [CD]. Given a bihomogeneous polynomial $f$ of several complex variables that is positive away from the origin, we proved that there is an integer $d$ so that $||z||^{2d} f(z,{\overline z})$ is the squared norm of a

T. D. Palev

This manuscript was published as a JINR Preprint E17-10550 in 1977. In view of the recent interest in various new kinds of statistics it seems the results it contains may be still of some interest. It is shown that the second quantization axioms can, in principle, be satisfied with creation and annihilation operators generating (in the case of $n$ pairs of s

R. Jackiw

Various gauge invariant but non-Yang-Mills dynamical models are discussed: Précis of Chern-Simons theory in (2+1)-dimensions and reduction to (1+1)-dimensional B-F theories; gauge theories for (1+1)-dimensional gravity-matter interactions; parity and gauge invariant mass term in (2+1)-dimensions.

T. H. Hansson, J. Wirstam, I. Zahed

We use dimensional reduction techniques to relate real time finite T correlation functions in (2+1) dimensional QCD to bound state parameters in a generalized 't Hooft model with an infinite number of heavy quark and adjoint scalar fields. While static susceptibilities and correlation functions of the DeTar type can be calculated using only the light (st

L. Andrianopoli, R. D'Auria, S. Ferrara

We find the topological entropy formula for all $N>2$ extended supergravities in five dimensions and the fixed scalar condition for the black-hole ``potential energy'' which extremizes the BPS mass. We comment upon the interpretation of these results in a string and M-theory setting.

Michael Gutperle

The scattering of NS-NS antisymmetric tensor states in the presence of D-instantons in type IIB superstring theory is studied. It is shown that in order to preserve gauge invariance, spacetime supersymmetry and picture changing symmetry the inclusion of boundary contact terms for closed string antisymmetric tensor vertex operators is necessary.

S. E. Derkachov, A. N. Manashov

The stability problem for the O(N) nonlinear sigma model in the 2+εdimensions is considered. We present the results of the 1/N^{2} order calculations of the critical exponents (in the 2<d<4 dimensions) of the composite operators relevant for this problem. The arguments in the favor of the scenario with the conventional fixed point are given.

Maxim Zabzine

We prove a C-theorem within the framework of two dimensional quantum field theories at finite temperature. There exists a function C(g) of coupling constants which is non-increasing along renormalization group trajectories and non-decreasing along temperature trajectory and stationary only at the fixed points. The connection between the C-theorem at zero tem

Adam F. Falk, Zoltan Ligeti, Mark B. Wise

The hadronic invariant mass spectrum for the inclusive charmless semileptonic decay $B\to X_u e \barν_e$ is studied. Particular attention is paid to the region $s_H<m_D^2$, which may be useful for extracting the value of $|V_{ub}|$. The sensitivity of the spectrum to the parameter $\barΛ\equiv m_B - m_b$ is explored. Perturbative QCD corrections to $dΓ/ds_H$

Nikolaos Kidonakis, George Sterman

We resum distributions that are singular at partonic threshold (the elastic limit) in heavy quark production, in terms of logarithmic behavior in moment space. The method may be applied to a variety of cross sections sensitive to the edge of phase space, including transverse momentum distributions. Beyond leading logarithm, dependence on the moment variable

G. P. Salam

This talks examines the effect of angular ordering on the small-x evolution of the unintegrated gluon distribution, and discusses the characteristic function for the CCFM equation.

M. Heyssler, W. J. Stirling

Hadronic antenna patterns can provide a valuable diagnostic tool for probing the origin of the apparent excess of high $x,Q^2$ events at HERA. We present quantitative predictions for the distributions of soft particles and jets in standard deep inelastic scattering $eq \to eq$ events and in events corresponding to the production of a narrow colour-triplet sc

K. -I. Izawa, Y. Nomura, K. Tobe, T. Yanagida

We systematically construct gauge-mediated supersymmetry(SUSY)-breaking models with direct transmission of SUSY-breaking effects to the standard-model sector. We obtain a natural model with the gravitino mass $m_{3/2}$ smaller than 1 keV as required from the standard cosmology. If all Yukawa coupling constants are of order one,the SUSY-breaking scale $m_{SUS

G. Domokos, S. Kovesi-Domokos

According to standard quantum theory, the time evolution operator of a quantum system is independent of the state of the system. One can, however, consider systems in which this is not the case: the evolution operator may depend on the density operator itself. The presence of such modifications of quantum theory can be tested in long baseline oscillation exp

Thomas DeGrand, Anna Hasenfratz, Tamas G. Kovacs

We study the topological content of the vacuum of SU(2) pure gauge theory using lattice simulations. We use a smoothing process based on the renormalization group equation which removes short distance fluctuations but preserves long distance structure. The action of the smoothed configurations is dominated by instantons, but they still show an area law for W

W. Bardeen, A. Duncan, E. Eichten, G. Hockney

In continuum QCD, nontrivial gauge topologies give rise to zero eigenvalues of the massless Dirac operator. In lattice QCD with Wilson fermions, these zero modes appear as exactly real eigenvalues of the Wilson-Dirac operator and hence as poles in the quark propagator in the vicinity of critical hopping parameter. It is shown that &#34;exceptional configurat

Mordehai Milgrom

I propound a non-linear generalization of the Poisson equation describing a &#34;medium&#34; in D dimensions with a &#34;dielectric constant&#34; proportional to the field strength to the power D-2. It is the only conformally invariant scalar theory that is second order, and in which the scalar $phi$ couples to the sources $ρ$ via a $ϕρ$ contact term. The sy

P. Baguis

We study the general geometrical structure of the coadjoint orbits of a semidirect product formed by a Lie group and a representation of this group on a vector space. The use of symplectic induction methods gives new insight into the structure of these orbits. In fact, each coadjoint orbit of such a group is obtained by symplectic induction on some coadjoint

G. Burdet

This note describes the construction of c U p-invariant differential operators on statistical manifolds, i.e. of operators canonically associated to a geometry which synthetizes the properties of conformal and projective geometries.

Guennady Y. Chitov, D. Senechal

We apply the finite-temperature renormalization-group (RG) to a model based on an effective action with a short-range repulsive interaction and a rotation invariant Fermi surface. The basic quantities of Fermi liquid theory, the Landau function and the scattering vertex, are calculated as fixed points of the RG flow in terms of the effective action&#39;s int

K. Fabricius, A. Klümper, U. Löw, B. Büchner

Experimental data for the magnetic susceptibility and magnetostriction of CuGeO_3 are analyzed within a one-dimensional antiferromagnetic model with nearest ({J_1}) and next-nearest neighbour interactions ({J_2}). We show that the ratio of the exchange constants in the antiferromagnetic chains of CuGeO_3 amounts to ${J_2}/{J_1}$ = 0.354(0.01), i.e. it is sig

G. Hildebrand, T. J. Hagenaars, W. Hanke, S. Grabowski

We show that important anomalous features of the normal-state thermoelectric power S of high-Tc materials can be understood as being caused by doping dependent short-range antiferromagnetic correlations. The theory is based on the fluctuation-exchange approximation applied to Hubbard model in the framework of the Kubo formalism. Firstly, the characteristic m

J. Sánchez-Cañizares, F. Sols

We study the transport properties of a NSN structure with an insulating barrier at each NS interface. Coherent quasiparticle scattering is assumed and self-consistency is implemented exactly to guarantee local charge conservation. The presence of a finite condensate flow has a greater influence on the transport properties than either the gap depression near

Adolfo Avella, Ferdinando Mancini, Dario Villani, Hideki Matsumoto

We have studied the t-t&#39;-U model by means of the composite operator method. The effect of the bare diagonal hopping term t&#39; that appears to be material dependent for high-Tc cuprate superconductors is analyzed in detail. In particular, some local quantities are computed and a comprehensive comparison with the data by numerical simulations on finite s

Yu. A. Krotov, D. -H. Lee, A. V. Balatsky

We study a simple model for the metallic stripes found in $La_{1.6-x}Nd_{0.4}Sr_xCuO_4$: two chain Hubbard ladder embedded in a static antiferromagnetic environments. We consider two cases: a ``topological stripe&#39;&#39;, for which the phase of the Neel order parameter shifts by $π$ across the ladder, and a ``non-topological stripe&#39;&#39;, for which the

A. Burrows, W. B. Hubbard, J. I. Lunine, M. Marley T. Guillot

With the discovery of the companions of 51 Peg, 55 Cnc, $τ$ Boo, $\upsilon$ And, 70 Vir, 47 UMa, and Gl229, evolutionary and spectral models of gas giants and/or brown dwarfs with masses from 0.3 through 60 times that of Jupiter assume a new and central role in the emerging field of extrasolar planetary studies. In this contribution, we describe the structur

Andrei V. Gruzinov

Perturbation theory is used to calculate the frequency shift of acoustic modes of an homogeneous turbulent fluid and the frequency shifts of solar modes due to turbulent convection. For sound waves in a random flow, the fractional frequency shift is +(11/30)M^2 in the long-wavelength limit, and the shift at short wavelengths is -(2/3)M^2, where M is the aver

W. F. Tompkins, B. B. Jones, P. L. Nolan, G. Kanbach

Recent observations of the Crab pulsar by the Energetic Gamma-Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory show that the high-energy gamma-ray light curve has changed little over the lifetime of the instrument. Previous data collected by SAS-2 and COS-B in the years 1972-82, along with earlier EGRET data, suggested a 14 year sinusoid

Gary Bernstein, Philippe Fischer, J. Anthony Tyson, George Rhee

New HST WFPC2 observations of the lensed double QSO 0957+561 will allow improved constraints on the lens mass distribution and hence will improve the derived value of H$_0$. We first present improved optical positions and photometry for the known components of this lens. The optical separation between the A and B quasar images agrees with VLBI data at the 10

Dimitar D. Sasselov

We review the basic concepts, the present state of theoretical models, and the future prospects for theory and observations of pulsating stellar atmospheres. Our emphasis is on radially pulsating cool stars, which dynamic atmospheres provide a general example for the differences with standard static model atmospheres.

Alison Sills, James C. Lombardi

We demonstrate the necessity of using realistic stellar models taken from stellar evolution codes, as opposed to polytropes, for starting models in smoothed particle hydrodynamics calculations of collisions between main sequence stars. Evolved stars have mean molecular weight gradients, which affect their entropy profiles and therefore affect how they react

Todd A. Small, Wallace L. W. Sargent, Donald Hamilton

We measure the field galaxy luminosity function (LF) as a function of color and redshift from z = 0 to z = 0.5 using galaxies from the Norris Survey of the Corona Borealis Supercluster. We find that our local r-band LF, when normalized to counts in high galactic latitude fields, agrees well with the local LF measured in the Las Campanas Redshift Survey. Our

Andrew Gould, Piotr Popowski, Donald M. Terndrup

We measure the zero point of the Stanek (1996) extinction map by comparing the observed (V-K) colors of 206 K giant stars with their intrinsic (V-K)_0 colors as derived from their Hβindices. We find that the zero point of the Stanek map should be changed by ΔA_V = -0.10 +/- 0.06 mag, obtaining as a bonus a three-fold reduction of the previous statistical err

Alison Sills, James C. Lombardi, Charles D. Bailyn, Pierre Demarque

We explore the evolution of collisionally merged stars in the blue straggler region of the HR diagram. The starting models for our stellar evolution calculations are the results of the smoothed particle hydrodynamics (SPH) simulations of parabolic collisions between main sequence stars performed by Lombardi, Rasio and Shapiro (1996). Since SPH and stellar ev

Claude Chevalier, Sergio A. Ilovaisky

We report the discovery of a new BY Dra-type binary identified as the optical counterpart of the bright source RX J0222.4+4729 detected during the ROSAT All-Sky Survey (Voges et al. 1996). The star is a $V \sim 11.1$, near-by ($\sim 30$ pc), close spectroscopic binary with an orbital period $P=0.46543 \pm 0.00001$ d. The absorption-line radial velocities wer

R. G. Moorhouse, A. B. Henriques, L. E. Mendes

We formulate a gradual dynamical transition from a power-law inflation era with a scalar field to a radiation era with no scalar field including inhomogeneous perturbations to the Friedmann- Robertson-Walker universe. We show that for the cosmic microwave background radiation fluctuations this is excellently approximated by a sudden transition, with applicat

J. Kaluzny, M. Kubiak, M. Szymanski, A. Udalski

Five fields located close to the center of the globular cluster NGC 104=47 Tuc were surveyed in a search for variable stars. We present V-band light curves for 42 variables. This sample includes 13 RR Lyr stars -- 12 of them belong to the Small Magellanic Cloud (SMC) and 1 is a background object from the galactic halo. Twelve eclipsing binaries were identifi

T. Totani, Y. Yoshii, K. Sato

We show that evolution of the luminosity density of galaxies in the universe provides a powerful test for the geometry of the universe. Using reasonable galaxy evolution models of population synthesis which reproduce the colors of local galaxies of various morphological types, we have calculated the luminosity density of galaxies as a function of redshift $z

Carlos Simpson

The purpose of this paper is to introduce the notion of mixed twistor structure, a generalization of the notion of mixed Hodge structure. The utility of this notion is to make possible a theory of weights for various things surrounding arbitrary representations of the fundamental group of a smooth projective variety. We give some examples of generalizations

A. A. Koulakov, B. I. Shklovskii

Charging of a clean two-dimensional island is studied in the regime of small concentration of electrons when they form the Wigner crystal. The number of electrons in the island is assumed to be not too big (N < 100). It is shown that the total energy of the island as a function of N has a quasi-periodic component of a universal shape, that is independent of

Jerome P. Gauntlett

BPS configurations of intersecting branes have many applications in string theory. We attempt to provide an introductory and pedagogical review of supergravity solutions corresponding to orthogonal BPS intersections of branes with an emphasis on eleven and ten space-time dimensions. Recent work on BPS solutions corresponding to non-orthogonally intersecting

L. Chekhov, K. Zarembo

We calculate an effective action and measure induced by the integration over the auxiliary field in the matrix model recently proposed to describe IIB superstrings. It is shown that the measure of integration over the auxiliary matrix is uniquely determined by locality and reparametrization invariance of the resulting effective action. The large--$N$ limit o

Matthias Burkardt

A phenomenological model for the quark structure of mesons is considered. The model is based on the tube model for QCD, where all quanta with nonzero transverse momenta are neglected. In the limit that the mass term of the gluons goes to infinity, the model is equivalent to a combination of the &#39;t Hooft and Gross-Neveu models and can be solved semi-analy

Benjamin Svetitsky, Nathan Weiss

We attempt the numerical construction of an effective action in three dimensions for Ising spins which represent the Wilson lines in the four-dimensional SU(3) gauge theory at finite temperature. For each configuration of the gauge theory, each spin is determined by averaging the Wilson lines over a small neighborhood and then projecting the average to +/-1

Yuan-ben Dai, Chao-shang Huang, Ming-qiu Huang, Hong-Ying Jin

The widths for pionic decays of lowest two excited doublets (0^+,1^+) and (1^+,2^+) of heavy mesons are studied with QCD sum rules in the leading order of heavy quark effective theory. The ambiguity due to presence of two distinct 1^+ states are solved. The soft pion approximation is not used.

A. Brotas

The purpose of this paper is to make clear the difference between rigid and undeformable bodies in Relativity. The error of confusing these two concepts has survived up to the present day treatises. We hope it will not persist in the XXI century treatises. The large majority of relativists do not know the formulae for the relativistic elasticity of rigid bod

B. S. Pudliner, V. R. Pandharipande, J. Carlson, Steven C. Pieper

We report quantum Monte Carlo calculations of ground and low-lying excited states for nuclei with A \leq 7 using a realistic Hamiltonian containing the Argonne v18 two-nucleon and Urbana IX three-nucleon potentials. A detailed description of the Green&#39;s function Monte Carlo algorithm for systems with state-dependent potentials is given and a number of te

Matthew G. Brin

We show that Thompson&#39;s group F occurs with great frequency in the group of PL homeomorphisms of the unit interval.

I. V. Volovich

We argue that black p-branes will occur in the collision of D0-branes at Planckian energies. This extents the Amati, Ciafaloni and Veneziano and &#39;t Hooft conjecture that black holes occur in the collision of two light particles at Planckian energies. We discuss a possible scenario for such a process by using colliding plane gravitational waves. D-branes

Hitoshi Sato

We study the Landau-Ginzburg models which correspond to Calabi-Yau four-folds. We construct the index of the typical states which correspond to toric divisors. This index shows that whether a corresponding divisor can generate a non-perturbative superpotential. For an application, we consider the phase transition in terms of the orbifold construction. We obt

Wei-Min Zhang

Based on the recently developed light-front similarity renormalization group approach and the light-front heavy quark effective theory, we derive analytically from first-principles QCD a heavy quark light-front Hamiltonian which contains explicitly a confinement interaction at long distances and a Coulomb-type interaction at short distances. With this light-

Wei-Min Zhang

In this series of lectures, I shall begin with the current investigations on phenomenology of hadron dynamics to demonstrate the importance of solving hadronic bound states within the framework of light-front (LF) QCD. Then, I will describe the basic procedure how to formulate the canonical theory of LFQCD, including light-front quantization of QCD, light-fr

Yoshio Kikukawa, Rajamani Narayanan, Herbert Neuberger

We describe in some detail a computer evaluation of a &#39;t Hooft vertex in a two dimensional model using the overlap. The computer result agrees with the known exact continuum value, and in this sense our work is a first successful fully dynamical simulation of a chiral gauge theory on the lattice. We add some new data to numbers obtained earlier and provi

Daniel M. Kaplan

The &#34;BTeV/C0&#34; experiment at Fermilab could reconstruct >10^9 charm decays, four orders of magnitude beyond the largest extant sample. The experiment is likely to run during Tevatron Run II (ca. 2000--2005). In addition to &#34;programmatic&#34; charm physics such as spectroscopy, lifetimes, and QCD tests, it will have significant new-physics reach in

Leonid Polterovich

There are two themes in the present paper. The first one is spelled out in the title, and is inspired by an attempt to find an analogue of Hersch-Yang-Yau estimate for $lambda_1$ of surfaces in symplectic category. In particular we prove that every split symplectic manifold $T^4 times M$ admits a compatible Riemannian metric whose first eigenvalue is arbitra

D. Han, Y. S. Kim, Marilyn E. Noz

According to Feynman, the universe consists of two parts - the system in which we are interested and the rest of the universe which our measurement process does not reach. Feynman then formulates the density matrix in terms of the observable world and the rest of the universe. It is shown that coupled harmonic oscillators can serve as an illustrative example

C. M. Savage, Janne Ruostekoski, Dan F. Walls

We propose an optical method for increasing the number of atoms in a pair of dilute gas Bose-Einstein condensates. The method uses laser-driven Raman transitions which scatter atoms between the condensate and non-condensate atom fractions. For a range of condensate phase differences there is destructive quantum interference of the amplitudes for scattering a

Shiho Kobayashi, Tsvi Piran, Re&#39;em Sari

We discuss the possibility that gamma-ray bursts result from internal shocks in an ultra-relativistic matter. Using a simple model we calculate the temporal structure and we estimate the efficiency of this process. In this model the ultra-relativistic matter flow is represented by a succession of shells with random values of the Lorentz factor. We calculate

Kai Nagel

Traffic simulations are made more realistic by giving individual drivers intentions, i.e. an idea of where they want to go. One possible implementation of this idea is to give each driver an exact pre-computed path, that is, a sequence of roads this driver wants to follow. This paper shows, in a realistic road network, how repeated simulations can be used so

Shigetaka Fukuda

We prove a base point free theorem for nef and log big divisors on log canonical surfaces.

T. M. Aliev, M. Savci, A. Ozpineci, H. Koru

The decay width, forward-backward asymmetry and tau lepton longitudinal and transversal polarization for the exclusive (B -> K tau^+ tau^-) decay in a two Higgs doublet model are computed. It is shown that the forward-backward asymmetry and longitudinal polarization of the tau lepton are very effective tools for establishing new physics.

Don D. Frantz

Heat capacity curves as functions of temperature were calculated using Monte Carlo methods for the series of Ne_(13-n)Ar_n clusters (0 <= n <= 13). The clusters were modeled classically using pairwise additive Lennard-Jones potentials. The J-walking (or jump-walking) method was used to overcome systematic errors due to quasiergodicity. Substantial discrepanc

S. Ansoldi, A. Aurilia, E. Spallucci

In the path integral formulation of quantum mechanics, Feynman and Hibbs noted that the trajectory of a particle is continuous but nowhere differentiable. We extend this result to the quantum mechanical path of a relativistic string and find that the ``trajectory&#39;&#39;, in this case, is a fractal surface with Hausdorff dimension three. Depending on the r

Helmuth Huffel, Gerald Kelnhofer

The helix model describes the minimal coupling of an abelian gauge field with three bosonic matter fields in 0+1 dimensions; it is a model without a global Gribov obstruction. We perform the stochastic quantization in configuration space and prove nonperturbatively equivalence with the path integral formalism. Major points of our approach are the geometrical

Thomas Husslein, Werner Fettes, Ingo Morgenstern

In this paper we compare numerical results for the ground state of the Hubbard model obtained by Quantum-Monte-Carlo simulations with results from exact and stochastic diagonalizations. We find good agreement for the ground state energy and superconducting correlations for both, the repulsive and attractive Hubbard model. Special emphasis lies on the superco

Emmanuel I. Rashba

A theory of the free induction signal from biexcitons and bound excitons is presented. The simultaneous existence of the exciton continuum and a bound state is shown to result in a new type of time dependence of the free induction. The optically detected signal increases in time and oscillates with increasing amplitude until damped by radiative or dephasing

K. Takahashi, H. M. Lee, S. Inagaki

The evolution of tidally truncated globular clusters is investigated by integrating two-dimensional Fokker-Planck equation that allows the development of velocity anisotropy. We start from the isotropic Plummer model with tidal cut off and followed the evolution through the corecollapse. The heating by three-binary is included to obtain the evolution past th

Sergei Nayakshin, Fulvio Melia

High-energy, multi-component plasmas in which pair creation and annihilation, lepton-lepton scattering, lepton-proton scattering, and Comptonization all contribute to establishing the particle and photon distributions, are present in a broad range of compact astrophysical objects. Earlier work has included much of the microphysics needed to account for elect

Andrea Huck, Anne van Otterlo, Manfred Sigrist

We study the physical properties of an $s$-wave -- normal metal -- $d$-wave junction in terms of the Andreev bound states in the normal metal layer. The phase dependence of bound states with different orientations leads to superconducting states with broken time reversal symmetry for generic orientations of the $d$-wave superconductor crystal. The occurrence

S. J. Brodsky, C. -R. Ji, A. Pang, D. G. Robertson

We use the BLM method to fix the renormalization scale of the QCD coupling in exclusive hadronic amplitudes such as the pion form factor and the photon-to-pion transition form factor at large momentum transfer. Renormalization-scheme-independent commensurate scale relations are established which connect the hard scattering subprocess amplitudes that control

D. Belitz, T. R. Kirkpatrick

A theory that predicts a spin-triplet, even-parity superconducting ground state in two-dimensional electron systems is re-analyzed in the light of recent experiments showing a possible insulator-to-conductor transition in such systems. It is shown that the observations are consistent with such an exotic superconductivity mechanism, and predictions are made f

Maxim Braverman

We introduce Morse-type inequalities for a holomorphic circle action on a holomorphic vector bundle over a compact Kaehler manifold. Our inequalities produce bounds on the multiplicities of weights occurring in the twisted Dolbeault cohomology in terms of the data of the fixed points and of the symplectic reduction. This result generalizes both Wu-Zhang exte

P. R. Broussard, M. A. Wall, J. Talvacchio

Using 4-circle x-ray diffraction and transmission electron microscopy we have studied the microstructure and in-plane orientation of the phases present in thin film composite mixtures of YBa(2)Cu(3)O(7) and Y(2)O(3). We see a high degree of in-plane orientation and have verified a previous prediction for the in-plane order of Y(2)BaCuO(5) on (110) MgO. Trans

Ziwei Lin, Ramona Vogt, Xin-Nian Wang

We study the effect of energy loss on charm and bottom quarks in high-energy heavy-ion collisions including longitudinal expansion and partial thermalization. We find that high $p_\perp$ heavy quarks are greatly suppressed, and consequently, high-mass dileptons from heavy quark decays are also suppressed. We consider in detail the detector geometry and singl

Naichung Conan Leung

We characteristize those Einstein four manifolds which are locally symmetric spaces of noncompact type. Namely they are four manifolds which admit solutions to the (non-Abelian) Seiberg Witten equations and satisty certain characterisitc number equality.

G. V. Dass, K. V. L. Sarma

Correlations that signal direct CP violation in the bottom sector are suggested. They need data on $Z\to b\bar b$ events which consist of a bottom hadron decay into an exclusive semileptonic channel $h \ell ν$ (where $h$ is a hadron), and the other bottom hadron decay into a multi-body final state that manifests as a jet in the opposite hemisphere.

Friedemann Brandt, Marc Henneaux, André Wilch

The antifield formalism is extended so as to incorporate the rigid symmetries of a given theory. To that end, it is necessary to introduce global ghosts not only for the given rigid symmetries, but also for all the higher order conservation laws, associated with conserved antisymmetric tensors. Otherwise, one may encounter obstructions of the type discussed

Felix Finster

It is shown that the Dirac sea can be uniquely defined for the Dirac equation with general interaction, if we impose a causality condition on the Dirac sea. We derive an explicit formula for the Dirac sea in terms of a power series in the bosonic potentials. The construction is extended to systems of Dirac seas. If the system contains chiral fermions, the ca

J. Ambjorn, K. N. Anagnostopoulos, U. Magnea

We study the zeros in the complex plane of the partition function for the Ising model coupled to 2d quantum gravity for complex magnetic field and real temperature, and for complex temperature and real magnetic field, respectively. We compute the zeros by using the exact solution coming from a two matrix model and by Monte Carlo simulations of Ising spins on

G. Ecker, M. Mojzis

We establish exact relations between relativistic form factors and amplitudes for single-baryon processes and the corresponding quantities calculated in the framework of heavy baryon chiral perturbation theory. A crucial ingredient for the proper matching is the first complete treatment of baryon wave function renormalization in heavy baryon chiral perturbat

Attilio Cucchieri

We study the influence of Gribov copies on gluon and ghost propagators, evaluated numerically in pure SU(2) lattice gauge theory in the minimal Landau gauge. Simulations are done at four different values of $β$ (namely $β$ = 0, 0.8, 1.6 and 2.7) and for volumes up to $16^4$ (up to $24^4$ at $β$ = 1.6). For the gluon propagator, Gribov noise seems to be of th

Yu. S. Barash, H. Burkhardt, A. A. Svidzinsky

Quasiparticle states bound to the boundary of anisotropically paired superconductors, their contributions to the density of states and to the conductance of NIS junctions are studied both analytically and numerically. For smooth surfaces and real order parameter we find some general results for the bound state energies. In particular, we show that under fair

N. Lutke-Entrup, B. Placais, P. Mathieu, Y. Simon

The surface impedance Z(f) of conventional isotropic materials has been carefully measured for frequencies f ranging from 1 kHz to 3 MHz, allowing a detailed investigation of the depinning transition. Our results exhibit the irrelevance of classical ideas to the dynamics of vortex pinning. We propose a new picture, where the linear ac response is entirely go

Kiyoshi Ezawa, Yutaka Matsuo, Koichi Murakami

We prove the Lorentz symmetry of supermembrane theory in the light cone gauge to complete the program initiated by de Wit, Marquard and Nicolai. We give some comments on extending the formulation to the M(atrix) theory.

Misha Verbitsky

Let X be a hyperkaehler manifold. Trianalytic subvarieties of X are subvarieties which are complex analytic with respect to all complex structures induced by the hyperkaehler structure. Given a K3 surface M, the Hilbert scheme classifying zero-dimensional subschemes of M admits a hyperkaehler structure. We show that for M generic, there are no trianalytic su

V. S. Dryuma, B. G. Konopelchenko

Equations of geodesic deviation for the 3-dimensional and 4-dimensional Riemann spaces are discussed. Availability of wide classes of exact solutions of such equations, due to recent results for the matrix Schrödinger equation, is demonstrated. Particular classes of exact solutions for the geodesic deviation equation as well as for the Raychaudhuri and gener

Christian Kassel, Marc Wambst

We set up a homological algebra for N-complexes, which are graded modules together with a degree -1 endomorphism d satisfying d^N=0. We define Tor- and Ext-groups for N-complexes and we compute them in terms of their classical counterparts (N=2). As an application, we get an alternative definition of the Hochschild homology of an associative algebra out of a

R. M. Santilli

An inspection of the contemporary physics literature reveals that, while matter is treated at all levels of study, from Newtonian mechanics to quantum field theory, antimatter is solely treated at the level of second quantization. For the purpose of initiating the restoration of full equivalence in the treatments of matter and antimatter in due time, in this

Abhijit Bhattacharyya, Sanjay K. Ghosh

The properties of baryonic matter have been investigated at finite density and temperature using different models. The variation of baryon masses and fractional number densities with baryon density and temperature obtained from different models have been compared. The quark hadron phase transition have been studied using Chiral Colour Dieletric (CCD) model i

W. R. Gibbs

An ab initio potential for the interaction of the neutral helium atom with antiprotons and protons is calculated using the Born-Oppenheimer approximation. Using this potential, the annihilation cross section for antiprotons in the energy range 0.01 microvolt to 1 eV is calculated.