October 1996 arXiv papers — page 6

M. Kachelriess, G. Wunner

The radiative decay $ν_H \to ν_L + γ$ of massive neutrinos is analyzed in the framework of the standard model with lepton mixing for very strong magnetic fields $B\gg B_{cr} = m_e^2/e \sim 4.14 \times 10^{13}$G. The analysis is based on the approximate decay amplitude obtained by Gvozdev et al. Numerical results as well as analytical approximations for the d

Pengfei Zhuang, Ulrich Heinz

We investigate in the equal-time formalism the derivation and truncation of infinite hierarchies of equations of motion for the energy moments of the covariant Wigner function. From these hierarchies we then extract kinetic equations for the physical distribution functions which are related to low-order energy moments, and show how to determine the higher or

Jochen Biebel, Tord Riemann

We calculate distributions for tau+ tau- gamma production at LEP 1 taking into account a potentially existing anomalous magnetic moment a_tau of the tau lepton. The existing upper limits for |a_tau| are known from the dependence of the decay Z -> tau+ tau- gamma on (a_tau)^2 and are of the order of (1 - 5)%. We show that such limits are also sensitive to lin

Marek Pawlowski, Ryszard Raczka

If the "Higgs mass" is not the physical mass of a real particle but rather an effective ultraviolet cutoff then a process energy dependence of this cutoff must be admitted. Precision data from at least two energy scale experimental points are necessary to test this hypothesis. The first set of precision data is provided by the $Z$-boson peak experime

Cristian Martinez, Jorge Zanelli

The first order corrections to the geometry of the (2+1)-dimensional black hole due to back-reaction of a massless conformal scalar field are computed. The renormalized stress energy tensor used as the source of Einstein equations is computed with the Green function for the black-hole background with transparent boundary conditions. This tensor has the same

Hisashi Onozawa

We compute the quasinormal frequencies of the Kerr black hole using a continued fraction method. The continued fraction method first proposed by Leaver is still the only known method stable and accurate for the numerical determination of the Kerr quasinormal frequencies. We numerically obtain not only the slowly but also the rapidly damped quasinormal freque

Ilja Schmelzer

We define a new paradigm --- postrelativity --- based on the hypothesis of a preferred hidden Newtonian frame in relativistic theories. It leads to a modification of general relativity with ether interpretation, without topological problems, black hole and big bang singularities. Semiclassical theory predicts Hawking radiation with evaporation before horizon

F. Gerl, U. Krey

Within a Kuhn-Tucker cavity method introduced in a former paper, we study optimal stability learning for situations, where in the replica formalism the replica symmetry may be broken, namely (i) the case of a simple perceptron above the critical loading, and (ii) the case of two-layer AND-perceptrons, if one learns with maximal stability. We find that the de

S. Moukouri, L. G. Caron

It is shown that White's density matrix renormalization group technique can be adapted to obtain thermodynamic quantities. As an illustration, the magnetic susceptibility of Heisenberg S=1/2 and S=3/2 spin chains are computed. A careful finite size analysis is made to determine the range of temperatures where the results are reliable. For the S=1/2 chain

T. Lorenz, U. Ammerahl, R. Ziemes, B. Buechner

We present high resolution measurements of the specific heat and the thermal expansion of the inorganic spin--Peierls cuprate CuGeO_3 in a magnetic field of 16 Tesla. At the transition from the incommensurate to the uniform phase both quantities show pronounced anomalies, which allow to derive the uniaxial pressure dependencies of the transition temperature.

Paul J. M. Bastiaansen, Hubert J. F. Knops

We argue that colossal magnetoresistance is a critical phenomenon and propose a mechanism to describe it. The mechanism relies on the halfmetallic behavior of the materials showing colossal magnetoresistance, and yields a correlated percolation model that, we argue, captures all qualitative features of colossal magnetoresistance, above as well as below the C

A. Ciach, U. Ritschel

We study the surface critical behavior of semi-infinite systems belonging to the bulk universality class of the Ising model. Special attention is paid to the local behavior of experimentally relevant quantities such as the order parameter and the correlation function in the crossover regimes between different surface universality classes, where the surface f

D. Malzahn, A. Engel, I. Kanter

We consider an ensemble of $K$ single-layer perceptrons exposed to random inputs and investigate the conditions under which the couplings of these perceptrons can be chosen such that prescribed correlations between the outputs occur. A general formalism is introduced using a multi-perceptron costfunction that allows to determine the maximal number of random

Uwe C. Täuber, Zoltán Rácz

We investigate nonequilibrium critical properties of $O(n)$-symmetric models with reversible mode-coupling terms. Specifically, a variant of the model of Sasvári, Schwabl, and Szépfalusy is studied, where violation of detailed balance is incorporated by allowing the order parameter and the dynamically coupled conserved quantities to be governed by heat baths

Fausto Borgonovi, Giulio Casati, Baowen Li

We study analytically and numerically the classical diffusive process which takes place in a chaotic billiard. This allows to estimate the conditions under which the statistical properties of eigenvalues and eigenfunctions can be described by Random Matrix Theory. In particular the phenomenon of quantum dynamical localization should be observable in real exp

E. Westerberg, A. Furusaki, M. Sigrist, P. A. Lee

The one-dimensional isotropic quantum Heisenberg spin systems with random couplings and random spin sizes are investigated using a real-space renormalization group scheme. It is demonstrated that these systems belong to a universality class of disordered spin systems, characterized by weakly coupled large effective spins. In this large-spin phase the uniform

C. Wolverton, Alex Zunger, B. Schonfeld

Physical properties of alloys are compared as computed from ``direct'' and ``inverse'' procedures. The direct procedure involves Monte Carlo simulations of a set of local density approximation (LDA)-derived pair and multibody interactions {ν_f}, generating short-range order (SRO), ground states, order- disorder transition temperatures, and st

Omri Gat, Victor S. L'vov, Evgenii Podivilov, Itamar Procaccia

The anomalous scaling behavior of the n-th order correlation functions ${\cal F}_n$ of the Kraichnan model of turbulent passive scalar advection is believed to be dominated by the homogeneous solutions (zero-modes) of the Kraichnan equation $\hat{\cal B}_n {\cal F}_n=0$. Previous analysis found zero-modes in perturbation theory in a small parameter. We prese

P. S. Coppi, F. A. Aharonian

VHE (Very High Energy, E>100 GeV) radiation emitted at cosmological distances will pair produce on low-energy diffuse extragalactic background radiation before ever reaching us. This prevents us from directly seeing most of the VHE emission in the Universe. However, a VHE gamma-ray that pair produces initiates an electromagnetic pair cascade. At low energies

João F. C. Santos, Jay A. Frogel

We examine the influence of stochastic effects on the integrated near-infrared light of star clusters with ages between 7.5<log(t)<9.25. To do this, we use stellar evolution models and a Monte Carlo technique to simulate the effects of stochastic variations in the numbers of main sequence, giant, and supergiant stars for single-generation stellar populations

Pedro G. Ferreira, Joao Magueijo

Gaussian cosmic microwave background skies are fully specified by the power spectrum. The conventional method of characterizing non-Gaussian skies is to evaluate higher order moments, the n-point functions and their Fourier transforms. We argue that this method is inefficient, due to the redundancy of information existing in the complete set of moments. In t

A. Kashlinsky, R. Jimenez

The epoch of galaxy formation provides an important additional test of cosmological theories. Cold-dark-matter (CDM) models with cosmological constant ($Λ$) are designed to account for the observed excess power in galaxy distribution, but at the same time suppress the power on small scales pushing galaxy formation to recent epochs. We point out that the rece

Gustavo A. Medina Tanco, Elisabete M. de Gouveia Dal Pino, Jorge E. Horvath

We report the results of 3-D simulations of non-diffusive propagation of Ultra-High Energy Cosmic Rays (UHECR) (E > 10^{20} eV) through the intergalactic and extended halo media. We quantify the expected angular and temporal correlations between the events and the sources, and the temporal delay between protons and gamma-ray counterparts with a common origin

Oleg Y. Gnedin

We consider the observational signature of the dynamical effects on the luminosity function of globular clusters. For the three best studied systems, in Milky Way, M31, and M87, there is a statistically significant difference between the inner and outer population of globular clusters. In all cases the inner clusters are on average brighter than the outer cl

R. van Ojik, H. J. A. Röttgering, P. P. van der Werf, G. K. Miley

We present results of an extensive search for molecular gas in 14 high redshift ($z>2$) radio galaxies. Radio galaxies with redshifts between 2.0 and 4.3 were observed during several sessions on two different single-dish telescopes (IRAM and JCMT) and two interferometric arrays (VLA and OVRO). No significant CO emission to a 2$σ$ limit of a few times 10^{10}

A. Biviano, P. Katgert, A. Mazure, M. Moles

We have studied the frequency of occurrence, the kinematics and the spatial distribution of Emission-Line Galaxies (ELG) in clusters in the ESO Nearby Abell Cluster Survey (ENACS). More than 90% of the ELG are spirals, but the ELG represent only 30% of all spirals. The true ELG fraction in clusters is 0.10; this is consistent with that in the field (0.21) as

P. Mayr

We study aspects of Calabi-Yau four-folds as compactification manifolds of F-theory, using mirror symmetry of toric hypersurfaces. Correlation functions of the topological field theory are determined directly in terms of a natural ring structure of divisors and the period integrals, and subsequently used to extract invariants of moduli spaces of rational cur

Davison E. Soper

Jet production in high energy hadron-hadron collisions can serve as a probe for new physics. I review recent data from CDF and D0 on the high E_T jet cross section. Reporting on recent work of the CTEQ collaboration, I argue that the apparent excess seen in the CDF data may be due to the gluon distribution function used in the theoretical calculation being t

Karsten M. Heeger, R. G. H. Robertson

Tests, independent of any solar model, can be made of whether solar neutrino experiments are consistent with the minimal Standard Model (stable, massless neutrinos). If the experimental uncertainties are correctly estimated and the sun is generating energy by light-element fusion in quasi-static equilibrium, the probability of a standard-physics solution is

Sean Gavin, Ramona Vogt

CERN collaboration NA50 has measured charmonium and Drell-Yan dimuon production in Pb+Pb collisions. Parton scattering broadens the transverse momentum, p_T, distributions for these processes. We predict that the average p_T^{2} will flatten in Pb+Pb collisions as a function of the neutral transverse energy of hadrons, E_T, in contrast to the almost-linear r

Tomislav Kundic, Edwin L. Turner, Wesley N. Colley, J. Richard Gott

Photometric monitoring of the gravitational lens system 0957+561A,B in the g and r bands with the Apache Point Observatory (APO) 3.5 m telescope during 1996 shows a sharp g band event in the trailing (B) image light curve at the precise time predicted from the observation of an event during 1995 in the leading (A) image with a delay of 415 days. This success

M. Diehl

We investigate azimuthal correlations in deep inelastic diffractive scattering, e + p -> e + \tilde{p} + X. The dependence of the ep cross section on the angle between the lepton plane and some direction in the hadronic final state can be written in a simple form; its measurement can be used to constrain the cross section for longitudinally polarised photons

S. Hardt, J. Geiss, H. Lenske, U. Mosel

The tensor-RPA approach developed previously in part I is applied to the Nambu-Jona-Lasinio (NJL) model. As a first step we investigate the structure of Dirac-Hartree-Fock solutions for a rotationally and isospin invariant ground-state density. Whereas vacuum properties can be reproduced, no solitonic configuration for a system with unit baryon number is fou

Marek Gierlinski, Andrzej A. Zdziarski, Chris Done, W. Neil Johnson

We present four X-ray/gamma-ray spectra of Cyg X-1 observed in the hard (&#39;low&#39;) state simultaneously by Ginga and GRO/OSSE on 1991 July 6. The 3-30 keV Ginga spectra are well represented by power laws with an energy spectral index of alpha~0.6 and a Compton reflection component including a fluorescent Fe K-alpha corresponding to the solid angle of th

A. M. Saitta, D. Alfe`, S. de Gironcoli, S. Baroni

The cubic-to-orthorhombic structural transition occurring in CsH at a pressure of about 17 GPa is studied by ab initio calculations. The relative stability of the competing structures and the transition pressure are correctly predicted. We show that this pressure-induced first-order transition is intimately related to a displacive second-order transition whi

P. Olesen

We consider primordial spectra with simple power behaviours and show that in the Navier-Stokes and magnetohydrodynamics equations without forcing, there exists systems in three dimensions with a subsequent inverse cascade, transferring energy from small to large spatial scales. This can have consequences in astrophysics for the evolution of density fluctuati

C. D&#39;Helon, G. J. Milburn

We propose two quantum error correction schemes which increase the maximum storage time for qubits in a system of cold trapped ions, using a minimal number of ancillary qubits. Both schemes consider only the errors introduced by the decoherence due to spontaneous emission from the upper levels of the ions. Continuous monitoring of the ion fluorescence is use

Claudia Eberlein

Reply to Comments by Lambrecht, Jaekel, and Reynaud, and by Garcia and Levanyuk, submitted to Physical Review Letters.

Lev Vaidman

A brief review of interaction-free measurements (IFM) is presented. The IFM is a solution of a quantum puzzle: How to test a bomb which explodes on every test without exploding it? This paper was given in the Oxford conference in honor of Roger Penrose.

Goeran Faeldt, Colin Wilkin

The normalisation relation between the bound and scattering S-state wave functions, extrapolated to the bound state pole, is derived from the Schroedinger equation. It is shown that, unlike previous work, the result does not depend on the details of the potential through the corresponding Jost function but is given uniquely in terms of the binding energy. Th

J. Rayford Nix, Peter Moller

Properties of 8,979 nuclei ranging from oxygen-16 to Z = 136, A = 339 and extending from the proton drip line to the neutron drip line have been calculated by use of the 1992 version of the finite-range droplet model. The calculated quantities include the ground-state mass, deformation, microscopic correction, odd-proton and odd-neutron spins and parities, p

Nico M. Temme

We give asymptotic approximations of the zeros of certain high degree polynomials. The zeros can be used to compute the filter coefficients in the dilation equations which define the compactly supported orthogonal Daubechies wavelets. Computational schemes are presented to obtain the numerical values of the zeros within high precision.

Krzysztof Stempak, Walter Trebels

Connections between Hankel transforms of different order for $L^p$-functions are examined. Well known are the results of Guy [Guy] and Schindler [Sch]. Further relations result from projection formulae for Bessel functions of different order. Consequences for Hankel multipliers are exhibited and implications for radial Fourier multipliers on Euclidean spaces

V. I. Fernandez, C. M. Naon

We extend a previously developed technique for computing spin-spin critical correlators in the 2d Ising model, to the case of multiple correlations. This enables us to derive Kadanoff-Ceva&#39;s formula in a simple and elegant way. We also exploit a doubling procedure in order to evaluate the critical exponent of the polarization operator in the Baxter model

J. A. Nieto, J. Socorro

In this work we raise the question whether nonsymmetric gravity and string theory are related. We start making the observation, that the gravitational field $ g_{μν}$ and the nonsymmetric gauge field $ A_{μν}$ arising in the low energy limit in the string theory are exactly the same two basic fields used in four dimensions in nonsymmetric gravity. We argue,

A. Giveon, M. Porrati

In this talk, some aspects of duality symmetries are presented.

L. V. Avdeev, D. I. Kazakov, M. Yu. Kalmykov

We investigate the consistency of the background-field formalism when applying various regularizations and renormalization schemes. By an example of a two-dimensional $σ$ model it is demonstrated that the background-field method gives incorrect results when the regularization (and/or renormalization) is noninvariant. In particular, it is found that the cut-o

William B. Kilgore, W. T. Giele

We report the results of a next-to-leading order event generator of purely gluonic jet production. This calculation is the first step in the construction of a full next-to-leading order calculation of three jet production at hadron colliders. Several jet-algorithms commonly used in experiments are implemented and their numerical stability is investigated.

Gia Dvali, Stefan Pokorski

The anomalous U(1)_A symmetry provides a generic method of getting accidental symmetries. Therefore, it can play a crucial role in solving the doublet-triplet splitting and the μ-problems via the `pseudo-Goldstone&#39; mechanism: U(1)_A can naturally uncorrelate the two grand unified Higgs sectors in the superpotential and simultaneously induce the desired e

T. L. Trueman

Methods for limiting the size of hadronic spin-flip in the Coulomb-Nuclear Interference region are critically assessed. This work was presented at the High Energy Polarimetry Workshop in Amsterdam, Sept.9, 1996 and the RHIC Spin Collaboration meeting in Marseille, Sept. 17, 1996.

J. Blümlein, S. Riemersma, A. Vogt

A brief overview is presented of recent developments concerning resummed small-x evolution, based upon the renormalization group equation. The non-singlet and singlet structure functions are discussed for both polarized and unpolarized deep-inelastic scattering. Quantitative results are displayed and uncertainties from uncalculated subleading terms are discu

Frank Close

Some recent developments in the phenomenology of the lightest scalar glueball are summarised. Tools for determining the gluonic content of a resonance of known mass, width and $J^{PC}$ from its branching fraction in radiative quarkonium decays and production cross section in $γγ$ collisions are presented. Two $q\bar{q} - G$ mixing schemes for $J^{PC} = 0^{++

Paolo Cea, Leonardo Cosmai

We analyze the problem of the Nielsen-Olesen unstable modes in the SU(2) lattice gauge theory by means of a recently introduced gauge-invariant effective action. We perform numerical simulations in the case of a constant Abelian chromomagnetic field. We find that for lattice sizes above a certain critical length the density of effective action shows a behavi

W. Drechsler

The use of internal variables for the description of relativistic particles with arbitrary mass and spin in terms of scalar functions is reviewed and applied to the stochastic phase space formulation of quantum mechanics. Following Bacry and Kihlberg a four-dimensional internal spin space $\bar S$ is chosen possessing an invariant measure and being able to r

R. Parentani

We describe radiative processes in Quantum Cosmology, from the solutions of the Wheeler De Witt equation. By virtue of this constraint equation, the quantum propagation of gravity is modified by the matter interaction hamiltonian at the level of amplitudes. In this we generalize previous works where gravity was coupled only to expectation values of matter op

R. Parentani

The aim of this article is twofold. First we examine from a new angle the question of recovery of time in quantum cosmology. We construct Green functions for matter fields from the solutions of the Wheeler De Witt equation. For simplicity we work in a mini-superspace context. By evaluating these Green functions in a first order development of the energy ``in

Yoshinari Inoue

We give a generalization of the Penrose transform on Hermitian manifolds with metrics locally conformally equivalent to Bochner-Kähler metrics. We also give an explicit formula for the inverse transform. This paper is a generalization of &#34;The Twistor correspondence of the Dolbeault complex over $\C^n$&#34; (dg-ga/9501004) and intended to supersede it.

Ming-Hsien Tu, Min-Fong Yang

Using the path-integral approach developed by Brézin et al. [ Nucl.Phys.B235, 24 (1984) ], we obtain an analytical expression for the density of states of a spin-1/2 disordered two-dimensional electron gas in a strong, perpendicular magnetic field. The density of states of this system illustrates the interplay between the Zeeman splitting of Landau levels an

P. J. Hirschfeld, W. O. Putikka

We calculate the electronic thermal conductivity in a d-wave superconductor, including both the effect of impurity scattering and inelastic scattering by antiferromagnetic spin fluctuations. We analyze existing experiments, particularly with regard to the question of the relative importance of electronic and phononic contributions to the heat current, and to

Tao Chen, S. Teitel

We carry out simulations of the anisotropic uniformly frustrated 3D XY model, as a model for vortex line fluctuations in high Tc superconductors. We compute the phase diagram as a function of temperature and anisotropy, for a fixed applied magnetic field. We find that superconducting coherence parallel to the field persists into the vortex line liquid state,

B. C. Gupta, K. Kundu

The formation of Stationary Localized states due to a nonlinear dimeric impurity embedded in a perfect 1-d chain is studied here using the appropriate Discrete Nonlinear Schr$\ddot{o}$dinger Equation. Furthermore, the nonlinearity has the form, $χ|C|^σ$ where $C$ is the complex amplitude. A proper ansatz for the Localized state is introduced in the appropria

Eric V. Siegel, Kathleen R. McKeown

This paper presents a method for large corpus analysis to semantically classify an entire clause. In particular, we use cooccurrence statistics among similar clauses to determine the aspectual class of an input clause. The process examines linguistic features of clauses that are relevant to aspectual classification. A genetic algorithm determines what combin

P. M. Solomon, D. Downes, S. J. E. Radford, J. W. Barrett

We present CO observations of a large sample of ultraluminous IR galaxies out to z = 0.3. Most of the galaxies are interacting, but not completed mergers. All but one have high CO(1-0) luminosities, log(Lco [K-km/s-pc^2]) = 9.92 +/- 0.12. The dispersion in Lco is only 30%, less than that in the FIR luminosity. The integrated CO intensity correlates Strongly

Sidney van den Bergh

The luminosities of globular clusters are found to correlate with their half-light radii. The most luminous clusters have half-light radii r ~ 3 pc. Mean cluster luminosities are < Mv > = -6.64 +/- 0.26 for r < 2.0, < Mv > = -7.44 +/- 0.20 for 2.0 < r < 4.0 pc, and < Mv > = -6.57 +/- 0.21 for clusters with r > 4.0 pc. An even fainter value < Mv > = -5.85 +/-

Valerio Faraoni

We describe gravitational lensing by a gravitational wave, in the regime in which multiple images of a light source are created. We adapt the vector formalism employed for ordinary gravitational lenses to the case of a non-stationary spacetime, and we derive an approximate condition for multiple imaging. It is shown that certain astrophysical sources of grav

C. R. Keeton, C. S. Kochanek, U. Seljak

Galaxies modeled as singular isothermal ellipsoids with an axis ratio distribution similar to the observed axis ratio distribution of E and S0 galaxies are statistically consistent with both the observed numbers of two-image and four-image lenses and the inferred ellipticities of individual lenses. However, no four-image lens is well fit by the model (typica

Salvatore Capozziello, Ruggiero de Ritis, Vladimir Mank&#39;o, Alma Angela Marino

We introduce the notion of defocusing gravitational lens considering a MACHO located behind a light source with respect to an observer. The consequence of defocusing effect is a temporal variability of star luminosity which produces a gap instead of a peak as tell--tale signature in the light curve. General theory of (de)focusing rays (geodesics) in a gravit

R. Kneissl, R. Egger, G. Hasinger, A. M. Soltan

Results from a cross-correlation analysis between the COBE DMR 4 year, and ROSAT PSPC All-Sky Survey data are presented. Statistical comparisons between microwave and X-ray maps can probe interesting astrophysical environments and processes, such as e.g. the Sunyaev-Zel&#39;dovich effect in clusters of galaxies or the Integrated Sachs-Wolfe effect. In order

P. J. Armitage, C. J. Clarke

We investigate the evolution of circumstellar discs around T Tauri stars that are ejected from small stellar clusters within molecular clouds. In particular, we study how the interaction that leads to ejection may hasten the transition between Classical and Weak-lined T Tauri status. In our models, ejections of T Tauri stars at velocities of 3-10 km/s trunca

Michael S. Turner

The current state of affairs in big-bang nucleosynthesis is reviewed and controversies are discussed. The author concludes that the glass is half full.

C. L. Carilli, H. J. A. Rottgering, R. van Ojik, G. K. Miley

We present sensitive radio continuum images at high resolution of 37 radio galaxies at z > 2. The observations were made with the Very Large Array (VLA) at 4.7 GHz and 8.2 GHz, with typical resolutions of 0.45&#39;&#39; and 0.25&#39;&#39;, respectively. Images of total and polarized intensity, and spectral index, are presented. Values for total and polarized

Paolo Padovani

Active Galactic Nuclei (AGN) are ideal sources for multi-wavelength studies as their emission can cover almost 20 orders of magnitude in frequency from the radio to the gamma-ray band. After reviewing their basic properties, I will assess how well we know the multifrequency spectra of AGN as a class. I will then briefly illustrate how currently available and

Ezio Pignatelli, Giuseppe Galletta

We present a set of detailed, self-consistent, isotropic dynamical models for disc galaxies. We start from the hypothesis that each galaxy can be decomposed in a bulge, following the r^{1/4} law, and a disc with an exponential projected density profile; and that the isodensity surfaces of each component can be represented by similar concentric spheroids. Und

V. G. Gurzadyan, S. Torres

When considering the statistical properties of a bundle of cosmic microwave background (CMB) photons propagating through space, the effect of `mixing geodesics&#39; appears with a distinct signature that depends on the geometry of space. In a Universe with negative curvature this effect is expected to produce elongated anisotropy spots on CMB maps. We used C

Nikolai Uraltsev

An all-order resummation is performed for the effect of the running of the strong coupling in the zero recoil sum rule for the axial current and for the kinetic operator \vecπ^2. The perturbative corrections to well-defined objects of OPE turn out to be very moderate. The renormalization of the kinetic operator is addressed.

Stephen L. Adler, L. P. Horwitz

We review here the microcanonical and canonical ensembles constructed on an underlying generalized quantum dynamics and the algebraic properties of the conserved quantities. We discuss the structure imposed on the microcanonical entropy by the equilibrium conditions.

Jair Botina, Herschel Rabitz, Naseem Rahman

A new formalism for the optimal control of quantum mechanical physical observables is presented. This approach is based on an analogous classical control technique reported previously[J. Botina, H. Rabitz and N. Rahman, J. chem. Phys. Vol. 102, pag. 226 (1995)]. Quantum Lagrange multiplier functions are used to preserve a chosen subset of the observable dyna

Peter Leifer

Principle of ``Superrelativity&#39;&#39; has been proposed in order to avoid the contradiction between principle of relativity and foundations of quantum theory. Solutions of a newly derived non-linear Klein-Gordon equation presumably may be treated as primordial nonlocal elements of quantum theory. It is shown that in the framework of CP(N-1) model suppleme

Eric D&#39;Hoker, I. M. Krichever, D. H. Phong

We clarify the mass dependence of the effective prepotential in N=2 supersymmetric SU(N_c) gauge theories with an arbitrary number N_f<2N_c of flavors. The resulting differential equation for the prepotential extends the equations obtained previously for SU(2) and for zero masses. It can be viewed as an exact renormalization group equation for the prepotenti

Ali Chamseddine, Sergio Ferrara, Gary W. Gibbons, Renata Kallosh

Geometric Killing spinors which exist on AdS_{p+2} X S^{d-p-2} sometimes may be identified with supersymmetric Killing spinors. This explains the enhancement of unbroken supersymmetry near the p-brane horizon in d dimensions. The corresponding p-brane interpolates between two maximally supersymmetric vacua, at infinity and at the horizon. New case is studied

A. C. Avram, M. Kreuzer, M. Mandelberg, H. Skarke

We present two methods for studying fibrations of Calabi-Yau manifolds embedded in toric varieties described by single weight systems. We analyse 184,026 such spaces and identify among them 124,701 which are K3 fibrations. As some of the weights give rise to two or three distinct types of fibrations, the total number we find is 167,406. With our methods one

E. Boos, A. Pukhov, M. Sachwitz, H. J. Schreiber

For an electron-photon collider the complete tree-level cross sections of the reaction $γe \rightarrow νb \bar{b} W$ are computed at center-of-mass energies between 0.5 and 2.0 TeV, for top masses of 160 to 200 GeV and Higgs masses between 80 and 140 GeV within the Standard Model. It is shown that most of the $νb \bar{b}$ events are due to Higgs and $Z/γ^*$

M. Arneodo, A. Bialas, M. W. Krasny, T. Sloan

A study has been made of the physics interest and feasibility of experiments with nuclear beams in HERA. It is shown that such experiments widen considerably the horizon for probing QCD compared to that from free nucleon targets. In addition there is some sensitivity to physics beyond the standard model. Hence the option to include circulating nuclear beams

Y. Koike, N. Nishiyama

We discuss the $Q^2$ dependence of the chiral-odd twist-3 distribution $e(x,Q^2)$. The anomalous dimension matrix for the corresponding twist-3 operators is calculated in the one-loop level. This study completes the calculation of the anomalous dimension matrices for all the twist-3 distributions together with the known results for the other twist-3 distribu

J. F. Gunion, J. Kelly

We delineate the techniques and prospects for using Higgs pair production in $e^+e^-$ or $μ^+μ^-$ collisions to probe GUT-scale boundary conditions in the minimal supersymmetric standard model.

Peter Leifer

The ordinary quantum theory points out that general relativity is negligible for spatial distances up to the Planck scale. Consistency in the foundations of the quantum theory requires a``soft&#39;&#39; spacetime structure of the general relativity at essentially longer length. However, for some reasons this appears to be not enough. A new framework (``super

A. Vikhlinin, W. Forman, C. Jones

We describe a wavelet transform analysis of the ROSAT PSPC images of the Coma cluster. On small scales, ~< 1&#39;, the wavelet analysis shows substructure dominated by two extended sources surrounding the two brightest cluster galaxies NGC 4874 and NGC 4889. On slightly larger scales, ~2&#39;, the wavelet analysis reveals a filament of X-ray emission origina

Brett Gladman, JJ Kavelaars

Motivated by a desire to understand the size distributon of the Kuiper Belt, an observing program was conducted at the Mount Palomar 5-m telescope from 1994-1996. The observations consisted of follow-up observations of known objects (in order to improve their very indeterminate orbits), and deep exposures on a single field to search for small objects below t

Marc Davis

This contribution is the affirmative side of a debate held with Dr. L. Pietronero at Princeton in June, 1996. I present the observational evidence that the fractal behavior which characterizes the small scale galaxy distribution does not continue to arbitarily large scale, but has a well defined cutoff with an outer length scale of order 30h$^{-1}$ Mpc. For

H. C. Rosu, J. Socorro

We briefly tackle the following concepts in the Demkov-Ostrovsky (DO) nodeless sector: (i) orbital impedance, (ii) orbital capacity, (iii) closeness to reflectionlessness. Moreover, using previous supersymmetric results for the DO problem, a strictly isospectral effect in the DO orbital impedances is discussed and explicit plots are displayed for the Maxwell

Ue-Li Pen

We re-examine the constraints which can be robustly obtained from the observed temperature function of X-ray cluster of galaxies. The cluster mass function has been thoroughly studied in simulations and analytically, but a direct simulation of the temperature function is presented here for the first time. Adaptive hydrodynamic simulations using the cosmologi

I. L. Buchbinder, V. D. Pershin, G. B. Toder

A method of constructing a canonical gauge invariant quantum formulation for a non-gauge classical theory depending on a set of parameters is advanced and then applied to the theory of closed bosonic string interacting with massive background fields. Choosing an ordering prescription and developing a suitable regularization technique we calculate quantum gua

Jeremy Michelson

Type IIB strings are compactified on a Calabi-Yau three-fold. When Calabi-Yau-valued expectation values are given to the NS-NS and RR three-form field strengths, the dilaton hypermultiplet becomes both electrically and magnetically charged. The resultant classical potential is calculated, and minima are found. At singular points in the moduli space, such as

J. F. Gunion, R. Vogt

Minijet production in $\sqrt{s} = 5.5$ TeV Pb+Pb collisions at the LHC is expected to produce a gluon-dominated plasma with large initial temperatures and energy densities. We discuss the implications of the high initial temperatures on the screening mass and on the relative suppression of members of the $Υ$ family. We demonstrate that $p_T$-dependence of th

Hitoshi Murayama

I first emphasize the importance of searching for nucleon decay in the context of supersymmetric models. The status of minimal SUSY SU(5) model is reviewed, which can be definitively ruled out by a combination of superKamiokande and LEP-2 experiments. Non-minimal models may provide some suppression in the nucleon decay rates, but there is still a good chance

Wei-Shu Hou

The vector glueball $O$, made of 3 valence gluons, is expected to be ``clean&#34;: it mixes less with quarkonia, but mediates OZI violations. The recent $0^{++} $ glueball candidate and the persistence of the $J/ψ, ψ&#39; \to ρπ$ puzzle suggest $m_O\simeq m_{J/ψ}$, with mixing angle $\sim 2^\circ - 4^\circ$, hence $Γ(O\to ρπ$, $K^+K^-$, $e^+e^-) \sim$ MeV, f

Julia M. Pryadko, Vahe Petrosian

We investigate the possibility of stochastic acceleration of background low-energy electrons by turbulent plasma waves. We consider the resonant interaction of the charged particles with all branches of the transverse plasma waves propagating parallel to a uniform magnetic field. Numerical results and asymptotic analytic solutions valid at non-relativistic a

J. F. Bell

The observational evidence for jets and phenomena arising from rotation powered radio pulsars is reviewed, including many recent and exciting discoveries at X-ray wavelengths. The well studied jets of the Crab pulsar are summarised, including recent results from the HST. The evolutionary links between the known binary radio pulsars and jets sources in X-ray

J. F. Bell

The motivation for radio pulsar timing and its basic principles are reviewed. Present and future radio timing techniques and hardware are summarised and compared. The array of present timing programmes and their scientific goals are collated and described. Recent results and future prospects are discussed, with emphasis on multi-wavelength techniques where a

Martin Cederwall, Alexander von Gussich, Bengt E. W. Nilsson, Anders Westerberg

We give the full supersymmetric and kappa-symmetric action for the Dirichlet three-brane, including its coupling to background superfields of ten-dimensional type IIB supergravity.