August 1997 arXiv papers — page 9

Gregory P. Korchemsky, Gianluca Oderda, George Sterman

We discuss power corrections to infrared safe cross sections and event shapes, and identify a nonperturbative function that governs 1/Q corrections to these quantities.

Tim Bolton

The formalism for extracting the CKM parameter $V_{cd}$ from $νN$ production of charm is discussed in some detail. The various model assumptions needed are clearly pointed out. A direct determination from neutrino induced dimuon production requires $νN$ charm production data, $% νN$ charm hadronization data, and the semi-muonic branching ratios for charmed h

The ALEPH Collaboration

Searches for scalar top and bottom quarks have been performed with data collected by the ALEPH detector at LEP. The data sample consists of 21.7 pb^-1 taken at sqrt{s} = 161, 170, and 172~GeV and 5.7 pb^-1 taken at sqrt{s} = 130 and 136~GeV. No evidence for scalar top quarks or scalar bottom quarks was found in the channels stop --> c chi, stop --> b l snu,

Claes R Cramer, Bernard S. Kay

We show that an analogue of the (four dimensional) image sum method can be used to reproduce the results, due to Krasnikov, that for the model of a real massless scalar field on the initial globally hyperbolic region IGH of two-dimensional Misner space there exist two-particle and thermal Hadamard states (built on the conformal vacuum) such that the (expecta

E. Ben-Naim, P. L. Krapivsky

We introduce a traffic flow model that incorporates clustering and passing. We obtain analytically the steady state characteristics of the flow from a Boltzmann-like equation. A single dimensionless parameter, R=c_0v_0t_0 with c_0 the concentration, v_0 the velocity range, and 1/t_0 the passing rate, determines the nature of the steady state. When R<<1, unin

Philip Nelson

The symmetries of the DNA double helix require a new term in its linear response to stress: the coupling between twist and stretch. Recent experiments with torsionally-constrained single molecules give the first direct measurement of this new material parameter. We extract its value from a recent experiment. We also present a very simple microscopic theory p

Daniel L. Miller

All the principal results of this work concern the vertical transport in generic three dimensional superlattices. In the 1st chapter we make an historical introduction, then we discuss the geometry of the problem, and the physical parameters associated with structure of electron minibands and strength of external fields. We found the effect of collisionless

L. P. Pitaevskii, S. Stringari

Landau damping in weakly interacting Bose gases is investigated by means of perturbation theory. Our approach points out the crucial role played by Bose-Einstein condensation and yields an explicit expression for the decay rate of elementary excitations in both uniform and non uniform gases. Systematic results are derived for the phonon width in homogeneous

C. Bulutay, I. Al-Hayek, M. Tomak

Accurate characterization of charged impurity centers is of importance for the electronic devices and materials. The role of valley-spin degeneracy on the screening of an attractive ion by the mobile carriers is assessed within a range of systems from spin-polarized single-valley to six-valley. The screening is treated using the self-consistent local-field c

Franco Bagnoli, Michele Bezzi

We investigate the problem of speciation and coexistence in simple ecosystems when the competition among individuals is included in the Eigen model for quasi-species. By suggesting an analogy between the competition among strains and the diffusion of a chemical inhibitor in a reaction-diffusion system, the speciation phenomenon is considered the analogous of

Sujata Tarafdar, Shashwati Roy

A growth model for porous sedimentary rocks is proposed, using a simple computer simulation algorithm. We generate the structure by ballistic deposition of particles with a bimodal size distribution. Porosity and specific surface area are calculated varying the proportion of small and larger particles. Permeability and its variation with porosity are studied

Satoshi Fujimoto, Norio Kawakami

We investigate the effects of quenched disorder on two chain Hubbard models at half-filling by using bosonization and renormalization group methods. It is found that the sufficiently strong forward scattering due to impurities and the random gauge field, which is generated by impurity backward scattering, destroy the charge gaps as well as the spin gaps. Ran

Jun-ichi Inoue, Hidetoshi Nishimori, Yoshiyuki Kabashima

We investigate the generalization ability of a simple perceptron trained in the off-line and on-line supervised modes. Examples are extracted from the teacher who is a non-monotonic perceptron. For this system, difficulties of training can be controlled continuously by changing a parameter of the teacher. We train the student by several learning strategies i

Lillian Lee

Valiant showed that Boolean matrix multiplication (BMM) can be used for CFG parsing. We prove a dual result: CFG parsers running in time $O(|G||w|^{3 - \myeps})$ on a grammar $G$ and a string $w$ can be used to multiply $m \times m$ Boolean matrices in time $O(m^{3 - \myeps/3})$. In the process we also provide a formal definition of parsing motivated by an i

Y. Sigad, A. Eldar, A. Dekel, M. A. Strauss

The galaxy density field as extracted from the IRAS 1.2 Jy redshift survey is compared to the mass density field as reconstructed by the POTENT method from the Mark III catalog of peculiar velocities. The reconstruction is done with Gaussian smoothing of radius 12 h^{-1}Mpc, and the comparison is carried out within volumes of effective radii 31-46 h^{-1}Mpc,

F. N. Owen, J. A. Eilek

The cluster Abell 2199 is one of the prototypical ``cooling flow&#39;&#39; clusters. Its central cD galaxy is host to a steep-spectrum radio source, of the type associated with cooling cores. In this paper we combine radio data with new ROSAT HRI data to show that conditions in its inner core, less than 50 kpc, are complex and interesting. Energy and momentu

John S. Mulchaey, Ann I. Zabludoff

We use ROSAT PSPC data to study the X-ray properties of a sample of twelve poor groups that have extensive membership information (Zabludoff and Mulchaey 1997; Paper I). Diffuse X-ray emission is detected in nine of these groups. In all but one of the X-ray detected groups, the X-ray emission is centered on a luminous elliptical galaxy. Fits to the surface b

Julia D. Kennefick, Patrick S. Osmer, Patrick B. Hall, Richard F. Green

We have made spectroscopic identifications of 39 additional quasar candidates from the Deep Multicolor Survey (DMS) of Hall et al. (1996, ApJ, 462, 614, astro-ph/9512052). We have identified 9 new quasars with 0.3 < z < 2.8 and 16.8 < B < 21.6, all from the group of candidates with ultraviolet excess (UVX). No new quasars with z > 3 were found among the obse

H. Wozniak, D. Friedli, L. Martinet, D. Pfenniger

For a sample of ten nearby barred galaxies, images at 6.75\um and 15\um of circumnuclear starbursts are being taken by ISOCAM on board of the ISO satellite. We first recall the main goals of our project, give its current status, and finally, as an example, preliminary results for NGC 4321 (M100) are presented.

P. Coles, R. C. Pearson, S. Borgani, M. Plionis

We study the geometry and topology of the large-scale structure traced by galaxy clusters in numerical simulations of a box of side 320 $h^{-1}$ Mpc, and compare them with available data on real clusters. The simulations we use are generated by the Zel&#39;dovich approximation, using the same methods as we have used in the first three papers in this series.

Shmuel Balberg

Creation of strange quark stars through strong interaction deconfinement is studied based on modern estimates of hyperon formation in neutron stars. The hyperon abundance is shown to be large enough so that if strange quark matter (SQM) is the true ground state of matter, the deconfinement density should be at most 2.5-3 times the nuclear saturation density.

Barbara Fantechi, Lothar Göttsche, Duco van Straten

We show that the Euler number of the compactified Jacobian of a rational curve $C$ with locally planar singularities is equal to the multiplicity of the $δ$-constant stratum in the base of a semi-universal deformation of $C$. In particular, the multiplicity assigned by Yau, Zaslow and Beauville to a rational curve on a K3 surface $S$ coincides with the multi

Paul Kornreich, John Scalo

We propose that galactic shocks propagating through interstellar density fluctuations provide a mechanism for the intermittent replenishment, or &#34;pumping,&#34; of the supersonic motions and internal density enhancements observed pervasively within cool atomic and molecular interstellar structures, without necessarily requiring the presence of self-gravit

I. Antoniadis, E. Gava, K. S. Narain, T. R. Taylor

Motivated by the work of Polchinski and Strominger on type IIA theory, where the effect of non-trivial field strengths for p-form potentials on a Calabi-Yau space was discussed, we study four-dimensional heterotic string theory in the presence of magnetic field on a 2-cycle in the internal manifold, for both N=4 and N=2 cases. We show that at special points

H. S. Park, G. G. Williams, E. Ables, D. L. Band

LOTIS is a gamma-ray burst optical counterpart search experiment located near Lawrence Livermore National Laboratory in California. Since operations began in October 1996, LOTIS has responded to five triggers as of July 30, 1997, which occurred during good weather conditions. GRB970223 (BATSE Trigger #6100) was an exceptionally strong burst lasting $\sim30$

Joshua Goodman

We present a variation on classic beam thresholding techniques that is up to an order of magnitude faster than the traditional method, at the same performance level. We also present a new thresholding technique, global thresholding, which, combined with the new beam thresholding, gives an additional factor of two improvement, and a novel technique, multiple

Edward R. Floyd

The trajectory and Copenhagen representations render different predictions for impulse perturbations. The different predictions are due to the different roles that causality plays in the trajectory and Copenhagen interpretations. We investigate a small perturbing impulse acting on the ground state of an infinitely deep square well. For the two representation

Martin Huthmann, Annette Zippelius

We study the exchange of kinetic energy between translational and rotational degrees of freedom for inelastic collisions of rough spheres. Even if equipartition holds in the initial state it is immediately destroyed by collisions. The simplest generalisation of the homogeneous cooling state allows for two temperatures, characterizing translational and rotati

A. Cobis, D. V. Fedorov, A. S. Jensen

We formulate a method to solve the coordinate space Faddeev equations for positive energies. The method employs hyperspherical coordinates and analytical expressions for the effective potentials at large distances. Realistic computations of the parameters of the resonances and the strength functions are carried out for the Borromean halo nucleus 6He (n+n+alp

C. Barbero, F. Krmpotic, D. Tadic

A derivation of the neutrinoless double beta decay rate, specially adapted for the nuclear structure calculations, is presented. It is shown that the Fourier-Bessel expansion of the hadronic currents, jointly with the angular momentum recoupling, leads to very simple final expressions for the nuclear form factors. This greatly facilitates the theoretical est

P. K. Townsend

Supersymmetric configurations of non-orthogonally intersecting M-5-branes can be obtained by rotation of one of a pair of parallel M-5-branes. Examples preserving 1/4, 3/16 and 1/8 supersymmetry are reviewed.

Hiroki Saito, Masahito Ueda

General principles and experimental schemes for generating a desired few-photon state from an aggregate of squeezed atoms are presented. Quantum-statistical information of the collective atomic dipole is found to be faithfully transferred to the photon state even in a few-photon regime. The controllability of few-photon states is shown to increase with incre

Matthias Lesch

We study various aspects of the noncommutative residue for an algebra of pseudodifferential operators whose symbols have an expansion $a\sim \sum_{j=0}^\infty a_{m-j}, a_{m-j}(x,ξ)=\sum_{l=0}^k a_{m-j,l}(x,ξ) \log^l|ξ|,$ where $a_{m-j,l}$ is homogeneous in $ξ$ of degree $m-j$. We will explain why this algebra of pseudodifferential operators is natural. For a

A. M. Ghezelbash, A. Shafiekhani, M. R. Abolhasani

We obtain the Picard-Fuchs equations of N=2 supersymmetric Yang-Mills theory with the exceptional gauge group E_6. Such equations are based on E_6 spectral curve.

M. Kirchbach

The gross features of the observed baryon excitation spectrum below 2 GeV are well explained if the spectrum generating algebra of its intrinsic orbital angular momentum states is o(4)*su(2)_I. The spins of the resonances are obtained through the coupling of a Lorentz bi-spinor (1/2,0)+ (0,1/ 2) to a multiplet of the type (j,j) in its O(4)/O(3) reduction. Th

UKQCD Collaboration, Luigi Del Debbio, Jonathan M. Flynn, Laurent Lellouch

We describe the form factors for B to rho lepton neutrino and B to K* gamma decays with just two parameters and the two form factors for B to pi lepton neutrino with a further two or three parameters. The parametrizations are consistent with heavy quark symmetry, kinematic constraints and lattice results, which we use to determine the parameters. In addition

S. R. Patel, S. M. Cronenwett, D. R. Stewart, A. G. Huibers

Distributions of Coulomb blockade peak spacing are reported for large ensembles of both unbroken (magnetic field B = 0) and broken (B <> 0) time reversal symmetry in GaAs quantum dots. Both distributions are symmetric and roughly gaussian with a width ~ 2-6% of the average spacing, with broad, non-gaussian tails. The distribution is systematically wider at B

Hongsu Kim, Jae-Sok Oh, Changrim Ahn

Utilizing the conformal-flatness nature of 3-dim. Anti-de Sitter (AdS_3) black hole solution of Banados, Teitelboim and Zanelli, the quantisation of conformally-coupled scalar and spinor fields in this background spacetime is explicitly carried out. In particular, mode expansion forms and propagators of the fields are obtained in closed forms. The vacuum in

Takahiko Matsubara, Yasushi Suto, Istvan Szapudi

We have evaluated a systematic effect on counts-in-cells analysis of deep, wide-field galaxy catalogues induced by the evolution of clustering within the survey volume. A multiplicative correction factor is explicitly presented, which can be applied after the higher order correlation functions have been extracted in the usual way, without taking into account

Tsafrir S. Kolatt, Matthias Bartelmann

We propose a method to remove the mass sheet degeneracy that arises when the mass of galaxy clusters is inferred from gravitational shear. The method utilizes high-redshift standard candles that undergo weak lensing. Natural candidates for such standard candles are type Ia supernovae (SN Ia). When corrected with the light-curve shape (LCS), the peak magnitud

E. Nielsen, D. V. Fedorov, A. S. Jensen

A method to study weakly bound three-body quantum systems in two dimensions is formulated in coordinate space for short-range potentials. Occurrences of spatially extended structures (halos) are investigated. Borromean systems are shown to exist in two dimensions for a certain class of potentials. An extensive numerical investigation shows that a weakly boun

B. Kaulakys, V. Gontis

Prevention of a quantum system&#39;s time evolution by repetitive, frequent measurements of the system&#39;s state has been called the quantum Zeno effect (or paradox). Here we investigate theoretically and numerically the effect of repeated measurements on the quantum dynamics of the multilevel systems that exhibit the quantum localization of the classical

I. Heckenberger, A. Schueler

Let $Γ$ be an $N^2$-dimensional bicovariant first order differential calculus on a Hopf algebra $SL_q(N)$. There are three possibilities to construct a differential Z-graded Hopf algebra $Γ^\wedge$ which contains $Γ$ as its first order part. Let $q$ be a transcendental complex number. For $N>2$ these three Z-graded Hopf algebras coincide. For Woronowicz&#39;

Katepalli R. Sreenivasan, Anupam Sahay

We argue that important elements of the dynamics of wall-bounded flows reside at the wall-normal position $y_p^+$ corresponding to the peak of the Reynolds shear stress. Specializing to pipe and channel flows, we show that the mean momentum balance in the neighborhood of $y_p^+$ is distinct in character from those in the classical inner and outer layers. We

Mark Byrd

The group SU(3) is parameterized in terms of generalized ``Euler angles&#39;&#39;. The differential operators of SU(3) corresponding to the Lie Algebra elements are obtained, the invariant forms are found, the group invariant volume element is found, and some relevant comments about the geometry of the group manifold are made.

Andre van Hameren, Ronald Kleiss, Jiri Hoogland

We consider the problem of finding, for a given quadratic measure of non-uniformity of a set of $N$ points (such as $L_2$ star-discrepancy or diaphony), the asymptotic distribution of this discrepancy for truly random points in the limit $N\to\infty$. We then examine the circumstances under which this distribution approaches a normal distribution. For large

A. E. A. Amorim, T. Frederico, Lauro Tomio

The parametric region in the plane defined by the ratios of the energies of the subsystems and the three body ground state, in which Efimov states can exist, is determined. We use a renormalizable model that guarantees the general validity of our results in the context of short range interactions. The experimental data for one and two-neutron separation ener

K. C. Chase, P. Bhattacharyya, A. Z. Mekjian

Similarities between models of fragmenting nuclei and disordered systems in condensed matter suggest corresponding methods. Several theoretical models of fragmentation investigated in this fashion show marked differences, indicating possible new methods for distinguishing models using yield data. Applying nuclear methods to disordered systems also yields int

S. J. Brodsky

Exclusive $γγ\to$ hadron pairs are among the most fundamental processes in QCD, providing a detailed examination of Compton scattering in the crossed channel. In the high momentum transfer domain $(s,t, {large},θ_{cm}$ for $t/s$ fixed), these processes can be computed from first principles in QCD, yielding important information on the nature of the QCD coupl

Zoltan Nagy, Zoltan Trocsanyi

We present a partonic Monte Carlo event generator that can be used for calculating the group independent kinematical functions of any infrared safe four-jet observable at NLO accuracy. As an example, we calculate the differential distribution of the $Π_1$ and $Π_4$ Fox-Wolfram moments. We find large K factors (K $>$ 2). The effect of the radiative correction

Zoltan Nagy, Zoltan Trocsanyi

Based upon a next-to-leading order perturbative calculation of the four-jet production rate in electron-positron annihilation and assuming 8 % for the theoretical error emerging from hadronization effects in the $0.002\le \ycut \le 0.004$ range for the Durham clustering algorithm, we exclude the existence of the light gluinos at the 95 % confidence level.

Zoltan Nagy, Zoltan Trocsanyi

We present the next-to-leading order partonic cross sections involving an electroweak vector boson and four massless partons (quarks, gluons or long living gluinos) in a general gauge theory with a simple Lie Group. The vector boson couples to a massless lepton pair and a quark-antiquark pair. The cross sections are given in terms of group independent kinema

J. Berges

We employ non-perturbative flow equations to compute the equation of state for two flavor QCD within an effective quark meson model. Our treatment covers both the chiral perturbation theory domain of validity and the domain of validity of universality associated with critical phenomena. In the vicinity of $T_c$ and zero quark mass we obtain a precision estim

J. Berges

We employ non-perturbative flow equations to compute the equation of state for two flavor QCD within an effective quark meson model. This yields the temperature and quark mass dependence of quantities like the chiral condensate or the pion mass. Our treatment covers both the chiral perturbation theory domain of validity and the domain of validity of universa

W. Hollik

This talk summarizes topical theoretical work for tests of the electroweak standard model and of the minimal supersymmetric standard model (MSSM). The status of the standard model and the MSSM is discussed in view of recent precision data. A brief theoretical summary of the Working Group on Electroweak Interactions is included.

Arnd Leike

The influence of the c.m. energy, integrated luminosity and systematic errors on Z&#39; exclusion limits and on errors of Z&#39; model measurements is discussed. Simple scaling laws are given for e+e-, pp (p (bar)p) and e+-p colliders and compared with results of exact analyses.

E. Leader, A. V. Sidorov, D. B. Stamenov

We have carried out a NLO analysis of the world data on polarized DIS in the MS/bare scheme. We have studied two models of the parametrizations of the input parton densities, the first due to Brodsky, Burkhardt and Schmidt (BBS) which gives a simultaneous parametrization for both the polarized and unpolarized densities and in which the counting rules are str

Gudrun Heinrich, Zoltan Kunszt

All the next-to-leading order results on Altarelli-Parisi splitting functions have been obtained in the literature either by using the operator product expansion method or by making use of the Curci Furmanski Petronzio (CFP) formalism in conjunction with light-like axial gauge, principal value (PV) prescription and dimensional regularization. In this paper w

M. S. Baek, S. Y. Choi, K. Hagiwara

A detailed, model-independent study of CP violation at present and future electron-positron colliders is reported. Firstly, we investigate CP violation effects in $W$ boson and $t$ quark pair production in $e^+e^-$ annihilation and in two-photon fusion at a next $e^+e^-$ linear collider, where Compton-backscattered laser light off the electrons or positrons

P. Poulose, Saurabh D. Rindani

We calculate the CP-violating electric and weak dipole form factors of the top quark and the tau lepton in models with scalar leptoquarks coupling only to the third generation of quarks and leptons. We obtain numerical values of the real and imaginary parts of these form factors at various energies for different values of leptoquark masses and couplings. The

Marcel Demarteau, Vassilis Koulovassilopoulos, Joseph Lykken, Fredrick I. Olness

We report on the activities of the Precision Measurements Of Heavy Objects working group of the Very Large Hadron Collider Physics and Detector Workshop.

Tetsuya Hattori, Hiroshi Watanabe

Chiral U(1) anomaly is derived with mathematical rigor for a Euclidean fermion coupled to a smooth external U(1) gauge field on an even dimensional torus as a continuum limit of lattice regularized fermion field theory with the Wilson term in the action. The present work rigorously proves for the first time that the Wilson term correctly reproduces the chira

Athanassios Z. Panagiotopoulos, Vicky Wong, M. Antonio Floriano

Histogram-reweighting Monte Carlo simulations were used to obtain polymer / solvent phase diagrams for lattice homopolymers of chain lengths up to r=1000 monomers. The simulation technique was based on performing a series of grand canonical Monte Carlo calculations for a small number of state points and combining the results to obtain the phase behavior of a

M. Potthoff, J. Lachnitt, W. Nolting, J. Braun

The one-step model of valence-band photoemission and inverse photoemission from single-crystal surfaces is reformulated for generalized (non-local, complex and energy-dependent) potentials. Thereby, it becomes possible to account for self-energy corrections taken from many-body electronic-structure calculations. The original formulation due to Pendry and co-

D. Ullmo, H. U. Baranger, K. Richter, F. von Oppen

We show that the classical dynamics of independent particles can determine the quantum properties of interacting electrons in the ballistic regime. This connection is established using diagrammatic perturbation theory and semiclassical finite-temperature Green functions. Specifically, the orbital magnetism is greatly enhanced over the Landau susceptibility b

F. Bagehorn, R. Hetzel

Although the Hubbard model is widely investigated, there are surprisingly few attempts to study the behavior of such a model in an external magnetic field. Using the Projector Quantum Monte Carlo technique, we show that the Hubbard model with an easy axis exhibits metamagnetic behavior if an external field is turned on. For the case of intermediate correlati

Janne Ruostekoski, M. J. Collett, Robert Graham, Dan F. Walls

We consider two dilute gas Bose-Einstein condensates with opposite velocities from which a monochromatic light field detuned far from the resonance of the optical transition is coherently scattered. In the thermodynamic limit, when the relative fluctuations of the atom number difference between the two condensates vanish, the relative phase between the Bose-

J. Robert Buchler

The light curves of the two large amplitude variable stars, R Scuti and AC Herculis, display irregular pulsation cycles with &#39;periods&#39; of 75 and 35 days, respectively. We review the evidence that the observed time-series are generated by low dimensional chaotic dynamics. In particular, a global flow reconstruction technique indicates that the minimum

K. Iwasawa, W. N. Brandt, A. C. Fabian

We present results from spectral analysis of ASCA data on the NLS1 Mrk 507. This galaxy was found to have an exceptionally flat ROSAT spectrum among the NLS1s. The ASCA spectrum however shows a clear absorption feature in the energy band below 2 keV, which partly accounts for the flat spectrum observed with the ROSAT PSPC. The absorption is mainly due to col

Ann I. Zabludoff, John S. Mulchaey

We use multi-fiber spectroscopy of 12 nearby, poor groups of galaxies to address whether the groups are bound systems or chance projections of galaxies along the line-of-sight, why the members of each group have not already merged to form a single galaxy, despite the groups&#39; high galaxy densities, short crossing times, and likely environments for galaxy-

Premana Premadi, Hugo Martel, Richard Matzner

We describe a numerical algorithm which simulates the propagation of light in inhomogeneous universes, using the multiple lens-plane method. The deformation and deflection of light beams as they interact with each lens plane are computed using the filled-beam approximation. We use a N-body code to simulate large-scale structure formation in the universe. We

F. Atrio-Barandela, J. Einasto, S. Gottlöber, V. Müller

We calculate temperature anisotropies of the cosmic microwave background (CMB) for several initial power spectra of density perturbations with a built-in scale suggested by recent optical data on the spatial distribution of rich clusters of galaxies. Using cosmological models with different values of spectral index, baryon fraction, Hubble constant and cosmo

K. Iwasawa, A. C. Fabian, W. N. Brandt, C. S. Crawford

We report the serendipitous detection of an X-ray source, AXJ1749+684, with the ASCA Gas Imaging Spectrometer. AXJ1749+684 is identified with a LINER/starburst-type spiral galaxy KUG 1750+683A at a redshift z = 0.05. It has a hard X-ray spectrum, consistent with that of the X-ray background (XRB) in the 1-10 keV band. Despite the optical classification, the

Heino Falcke, A. S. Wilson, L. C. Ho

We discuss radio observations of a sample of radio-weak and radio-intermediate quasars which demonstrate that - just like their radio-loud counterparts - radio-weak quasars too have relativistic jets in their nuclei. Moreover, a VLA survey of nearby LINER galaxies reveals a relatively large number of flat-spectrum radio cores. It is suggested that those core

C. Steidel, K. Adelberger, M. Dickinson, M. Giavalisco

We report the discovery of a highly significant concentration of galaxies at a redshift of <z>=3.090. The structure is evident in a redshift histogram of photometrically selected ``Lyman break&#39;&#39; objects in a 9&#39; by 18&#39; field in which we have obtained 78 spectroscopic redshifts in the range 2.0 < z <3.4. The dimensions of the structure projecte

Piotr Zycki, Chris Done, David Smith

We present results of spectral analysis of Ginga data obtained during the decline phase after the 1989 outburst of GS 2023+338 (V404 Cyg). Our analysis includes detailed modelling of the effects of X-ray reflection/reprocessing. We have found that (1) the contribution of the reprocessed component (both continuum and line) corresponds to the solid angle of th

C. Chiosi, A. Bressan, L. Portinari, R. Tantalo

In this paper, basic observational properties of elliptical galaxies such as the integrated spectra, the chemical abundances and the enhancement of $α$-elements inferred from broad-band colors and line strength indices $Mg_2$ and $< Fe >$ (and their gradients), the color-magnitude relation, the UV fluxes, and the mass-luminosity ratios, are examined in the l

H. Hirashita, H. Kamaya, S. Mineshige

We examine the possibility that ram pressure exerted by the galactic wind from the Galaxy could have stripped gas from the Local Group dwarf galaxies, thereby affecting their star formation histories. Whether gas stripping occurs or not depends on the relative magnitudes of two counteracting forces acting on gas in a dwarf galaxy: ram pressure force by the w

Steven Carlip

In the saddle point approximation, the Euclidean path integral for quantum gravity closely resembles a thermodynamic partition function, with the cosmological constant $Λ$ playing the role of temperature and the ``density of topologies&#39;&#39; acting as an effective density of states. For $Λ<0$, the density of topologies grows superexponentially, and the s

G. Degrassi, P. Gambino, M. Passera, A. Sirlin

Recent calculations have significantly decreased the scheme and residual scale dependence of basic radiative corrections of the Standard Electroweak Model. This leads to a theoretically accurate prediction of the W-boson mass M(W), as well as a reduced upper bound for the Higgs boson mass M(H). The implications of a precise M(W) measurement on the M(H) estim

Kingman Cheung, Duane A. Dicus, B. Dutta

The explanation of a 200 GeV R-parity violating squark to the HERA high-$Q^2$ anomaly would have an important impact on supersymmetry-breaking models. Here we show that a squark of mass around 200 GeV is disallowed in the minimal gauge-mediated SUSY-breaking models in the parameter space constrained by the radiative electroweak-symmetry breaking and the expe

Christopher Essex, Dallas C. Kennedy

A thermodynamical minimum principle valid for photon radiation is shown to hold for arbitrary geometries. It is successfully extended to neutrinos, in the zero mass and chemical potential case, following a parallel development of photon and neutrino statistics. This minimum principle stems more from that of Planck than that of classical Onsager- Prigogine ir

S. Khlebnikov

Resonant decay of the inflaton produces highly non-equilibrium states dominated by interacting classical waves. We discuss several topics in the theory of formation and evolution of such states.

W. Cassing, E. L. Bratkovskaya, R. Rapp, J. Wambach

We present a dynamical study of $e^+e^-$ and $μ^+ μ^-$ production in proton-nucleus and nucleus-nucleus collisions at CERN-SPS energies on the basis of the covariant transport approach HSD employing a momentum-dependent $ρ$-meson spectral function that includes the pion modifications in the nuclear medium as well as the polarization of the $ρ$-meson due to r

John P. Ralston, Borge Nodland

We review evidence for a new phenomenon in the propagation of radio waves across the Universe, an anisotropic rotation of the plane of polarization not accounted for by conventional physics.

E. Bruce Pitman

In this note we re-examine the classic Janssen theory for stresses in bins, including a randomness in the friction coefficient. The Janssen analysis relies on assumptions not met in practice; for this reason, we numerically solve the PDEs expressing balance of momentum in a bin, again including randomness in friction.

Raman Sundrum

The Cosmological Constant Problem is re-examined from an effective field theory perspective. While the connection between gravity and particle physics has not been experimentally probed in the quantum regime, it is severely constrained by the successes of Standard Model quantum field theory at short distances, and classical General Relativity at large distan

Andrei Mikhailov

It was observed recently, that the low energy effective action of the four-dimensional supersymmetric theories may be obtained as a certain limit of M Theory. From this point of view, the BPS states correspond to the minimal area membranes ending on the M Theory fivebrane. We prove that for the configuration, corresponding to the SU(2) Super Yang-Mills theor

Raimar Wulkenhaar

We present a mathematical framework of gauge theories that is based upon a skew-adjoint Lie algebra and a generalized Dirac operator, both acting on a Hilbert space.

V. E. Zavlin, G. G Pavlov

We show that the soft X-ray spectra and light curves observed with the ROSAT and EUVE from the closest known millisecond pulsar J0437--4715 can be interpreted as thermal radiation from two hot polar caps whose emitting layers (atmospheres) are comprised of hydrogen. The simplest model yields a uniform temperature of $(0.8-0.9)\times 10^6 K$ within a cap radi

Balazs Szendroi

We investigate the moduli theory of Calabi--Yau threefolds, and using Griffiths&#39; work on the period map, we derive some finiteness results. In particular, we confirm a prediction of Morrison&#39;s Cone Conjecture.

Fedja Hadrovic, James Binney

We show that the usual relation between redshift and angular-diameter distance can be obtained by considering light from a source to be gravitationally lensed by material that lies in the telescope beam as it passes from source to observer through an otherwise empty universe. This derivation yields an equation for the dependence of angular diameter on redshi

Andrew Steane

The subject of quantum computing brings together ideas from classical information theory, computer science, and quantum physics. This review aims to summarise not just quantum computing, but the whole subject of quantum information theory. It turns out that information theory and quantum mechanics fit together very well. In order to explain their relationshi

Konstantin G. Zloshchastiev

We give a comparative description of monopole and electrically charged spherically symmetric dust thin shells. Herewith we consider two of the most interesting configurations: the hollow shell and shell, surrounding a body with opposite charge. The classification of shells in accordance with the types of black holes and traversable wormholes is constructed.

Prabal K. Maiti, Debashish Chowdhury

We report the results of large scale Monte Carlo (MC) simulations of novel microscopic models of gemini surfactants to elucidate (i) their spontaneous aggregation in bulk water and (ii) their spatial organization in a system where water is separated from the air above it by a sharp well defined interface. We study the variation of the critical micellar conce

Chao-shang Huang, C. S. Kim

Non-perturbative parameters to the order ${\cal O}({1 \over m_Q})$ in HQET expansion, $\bar{ Λ}$, $λ_1$ and $λ_2$, as well as the masses, $m_b$ and $m_c$, are estimated phenomenologically from $B$ and $D$ meson system spectroscopy. We found relatively large value of $m_b$ and quite small value of $\bar{ Λ}$ compared to previous estimates.

A. J. S. Hamilton

Redshift maps of galaxies in the Universe are distorted by the peculiar velocities of galaxies along the line of sight. The amplitude of the distortions on large, linear scales yields a measurement of the linear redshift distortion parameter, which is $β\approx Ω_0^{0.6}/b$ in standard cosmology with cosmological density $Ω_0$ and light-to-mass bias $b$. All

Andrew Steane

Quantum error correction methods use processing power to combat noise. The noise level which can be tolerated in a fault-tolerant method is therefore a function of the computational resources available, especially the size of computer and degree of parallelism. I present an analysis of error correction with block codes, made fault-tolerant through the use of

C. Nowak

We prove the existence of a deformation quantization for integrable Poisson structures on R^3 and give a generalization for a special class of three dimensional manifolds.

Feng Xu

We give three applications of general theory about braided endomorphisms from conformal inclusions developed previously by us. The first is an example of subfactors associated with conformal inclusion whose dual fusion ring is non-commutative. In the second application we show that the Kac-Wakimoto hypothesis about certain relations between branching rules a