October 1999 arXiv papers — page 11

Xian-Geng Zhao, Daniel W. Hone

We extend, to include the effects of finite temperature, our earlier study of the interband dynamics of electrons with Markoffian dephasing under the influence of uniform static electric fields. We use a simple two-band tight-binding model and study the electric current response as a function of field strength and the model parameters. In addition to the Esa

Andrea Cavagna, Irene Giardina, Giorgio Parisi

In the context of the Instantaneous Normal Mode approach, the spectrum of the Hessian of Hamiltonian is a key quantity to describe liquids behaviour. The determination of the spectrum represents a major task for theoretical studies, and has been addressed recently in various works. In this paper a new approach for the analytic computation of the Hessian spec

David L. Feder, Charles W. Clark, Barry I. Schneider

The nucleation of vortices and the resulting structures of vortex arrays in dilute, trapped, zero-temperature Bose-Einstein condensates are investigated numerically. Vortices are generated by rotating a three-dimensional, anisotropic harmonic atom trap. The condensate ground state is obtained by propagating the Gross-Pitaevskii equation in imaginary time. Vo

Konstantin Kladko

We derive upper bounds for spin velocity in half-integer-spin Heisenberg antiferromagnetic chains. We relate these upper bounds to the instability of the gapless state, which is observed in frustrated systems.

Debanand Sa, R. Valenti, C. Gros

We develop a generalized Ginzburg-Landau theory for second harmonic generation (SHG) in magnets by expanding the free energy in terms of the order parameter in the magnetic phase and the susceptibility tensor in the corresponding high-temperature phase. The non-zero components of the SHG susceptibility in the ordered phase are derived from the symmetries of

Markus Deserno

A simple technique is proposed for numerically determining equilibrium ion distribution functions belonging to free energies of the Poisson-Boltzmann type. The central idea is to perform a conventional Monte-Carlo simulation using the free energy as the "Hamiltonian" entering the Metropolis criterion and the spatially discretized density as degrees o

P. L. Krapivsky, I. Grosse, E. Ben-Naim

We derive exact statistical properties of a class of recursive fragmentation processes. We show that introducing a fragmentation probability 0<p<1 leads to a purely algebraic size distribution in one dimension, P(x) ~ x^{-2p}. In d dimensions, the volume distribution diverges algebraically in the small fragment limit, P(V)\sim V^{-γ} with γ=2p^{1/d}. Hence,

Dierk Bormann, Hans Beck, Oliver Gallus, Massimiliano Capezzali

We study the dynamics of a classical, two-component plasma in two dimensions, in the vicinity of the Kosterlitz-Thouless (KT) transition where the system passes from a dielectric low-temperature phase (consisting of bound pairs) to a conducting phase. We use two ``complementary&#39;&#39; analytical approaches and compare to simulations. The conventional, ``i

D. Bukta, G. Karl, B. G. Nickel

We describe classical orbits and quantum states of a three particle system which is weakly chaotic. The quantum energies of the lowest 48 states which are invariant under permutations are given both in various approximations and to high accuracy. The quantum mechanical probability distributions are given in a two dimensional version of the system, the hexago

David V. Bowen, Katherine C. Roth, David M. Meyer, J. Chris Blades

We have observed SN1998S which exploded in NGC3877, with the UES at the WHT and with the E230M echelle of STIS aboard HST. Both data sets were obtained at two seperate epochs. From our own Galaxy we detect interstellar absorption lines of CaII, FeII, MgI, and probably MnII from the edge of the HVC Complex M. We derive gas-phase abundances which are very simi

J. Chaname, L. Infante, A. Reisenegger

NGC 1427A is a LMC-like irregular galaxy in the Fornax cluster with an extended pattern of strong star formation around one of its edges, which is probably due to some kind of interaction with the cluster environment. We present H-alpha velocities within NGC 1427A, obtained through long-slit spectroscopy at seven different positions, chosen to fall on the br

Ken D. Olum, J. J. Blanco-Pillado

We have simulated large-amplitude standing waves on an Abelian-Higgs cosmic string in classical lattice field theory. The radiation rate falls exponentially with wavelength, as one would expect from the field profile around a gauge string. Our results agree with those of Shellard and Moore, but not those of Vincent, Antunes, and Hindmarsh. The radiation rate

Nelson Padilla, Diego G. Lambas

We study the peculiar velocity field inferred from the Mark III spirals using a new method of analysis. We estimate optimal values of Tully-Fisher scatter and zero-point offset, and we derive the 3-dimensional rms peculiar velocity ($σ_v$) of the galaxies in the samples analysed. We check our statistical analysis using mock catalogs derived from numerical si

Scott E. Whitmire, Robert J. Scherrer

We examine Big Bang nucleosynthesis (BBN) in the case of inhomogenous neutrino degeneracy, in the limit where the fluctuations are sufficiently small on large length scales that the present-day element abundances are homogeneous. We consider two representive cases: degeneracy of the electron neutrino alone, and equal chemical potentials for all three neutrin

Tiziana Di Matteo, Steven W. Allen

We explore the implications of the discovery of hard, power-law X-ray sources in the spectra of nearby elliptical galaxies for the origin of the X-ray background. The spectra of these sources are consistent with models of thermal bremsstrahlung emission from low radiative efficiency accretion flows around central supermassive black holes and are unique in th

P. J. E. Peebles

It may prove useful in cosmology to understand the behavior of the energy distribution in a scalar field that interacts only with gravity and with itself by a pure quartic potential, because if such a field existed it would be gravitationally produced, as a squeezed state, during inflation. It is known that the mean energy density in such a field after infla

Casey Papovich, Colin A. Norman, David V. Bowen, Tim Heckman

We have studied a spectrum of Q0122+0338 (z = 1.202) obtained by the FOS on board HST. We present the analysis of three associated absorption systems at z = 1.207, 1.199 and 1.166. The most complex of these at z = 1.207 shows strong absorption from the highly ionized transitions of Lyman alpha, Lyman beta, N V, O VI, Si III, Si IV, and possibly P V. We deriv

F. Bertola, E. M. Corsini

Kinematical decoupling between two components of a galaxy suggests the occurrence of a second event. In disk galaxies it is usually observed as a counterrotation of the stellar disk with respect to the gaseous component and/or with respect to a second stellar disk. We discuss here three cases of kinematical orthogonal decoupling of the innermost region of th

R. B. C. Henry, K. B. Kwitter, J. A. Bates

This paper is the fourth and final report on a project designed to study carbon abundances in a sample of planetary nebulae representing a broad range in progenitor mass and metallicity. We present newly acquired optical spectrophotometric data for three Galactic planetary nebulae IC 418, NGC 2392, and NGC 3242 and combine them with UV data from the IUE Fina

R. S. Somerville, G. Rosenfeld, T. S. Kolatt, A. Dekel

Using high resolution N-body simulations with hydrodynamics and star formation, we investigate interactions and the resulting starbursts in galaxies with properties typical of $z\sim 3$. We apply spectral population models to produce mock-HST images, and discuss the observed magnitude, color, and morphological appearance of our simulated galaxies in both the

L. Colina, K. Wada

A combination of Hubble Space Telescope (HST) WFPC2 and NICMOS images are used to investigate the gas/dust and stellar structure inside the central 300 pc of the nearby active galaxy NGC 4303. The NICMOS H-band (F160W) image reveals a bright core and a nuclear elongated bar-like structure of 250 pc in diameter. The bar is centered on the bright core, and its

L. Colina, S. Arribas, K. Borne

Integral field optical spectroscopy with the INTEGRAL fiber-based systemis used to map the extended ionized regions and gas flows in Mrk 273, one of the closest Ultraluminous Infrared galaxies (ULIRGs). The Hbeta and [OIII]5007 maps show the presence of two distinct regions separated by 4&#39;&#39; (3.1 kpc) along position angle (PA) 240. The northeastern re

Garrelt Mellema

This review discusses the physics of the formation of planetary nebulae around low mass WR stars, or [WR] stars. It especially focuses on the differences which can be expected due to the different character of the fast winds from these [WR] stars. Their fast winds are more massive and are highly H deficient and metal enriched compared to the winds of normal

J. P. Blakeslee, M. Davis, J. L. Tonry, E. A. Ajhar

We compare the predicted local peculiar velocity field from the IRAS 1.2 Jy flux-limited redshift survey and the Optical Redshift Survey (ORS) to the measured peculiar velocities from the recently completed SBF Survey of Galaxy Distances. The analysis produces a value of β= Ω^{0.6}/b for the redshift surveys, where b is the linear biasing factor, and a tie t

T. Oosterbroek, A. N. Parmar, D. Dal Fiume, M. Orlandini

We present results of a 5.7 day duration BeppoSAX observation of the short-on state of Her X-1 and a short observation during the decline of the preceding main-on state. The 0.1-10 keV spectra can be fit with a power-law and blackbody model together with Fe emission features at 1.0 keV and 6.5 keV. During the later stages of the short-on state there are long

J. P. Blakeslee, M. Davis, J. L. Tonry, A. Dressler

We compare the peculiar velocities measured in the SBF Survey of Galaxy Distances with the predictions from the density fields of the IRAS 1.2 Jy flux-limited redshift survey and the Optical Redshift Survey (ORS) to derive simultaneous constraints on the Hubble constant $H_0$ and the density parameter $β= Ω^{0.6}/b$, where $b$ is the linear bias. We find $β_

A. E. Allahverdyan, V. G. Gurzadyan, A. A. Soghoyan

We consider the problem of numerical computation of the Kolmogorov complexity and the fractal dimension of the anisotropy spots of Cosmic Microwave Background (CMB) radiation. Namely, we describe an algorithm of estimation of the complexity of spots given by certain pixel configuration on a grid and represent the results of computations for a series of struc

K. Ioka, R. Nishi, Y. Kan-ya

We investigate the effects of the Kepler rotation of lens binaries on the binary-microlensing events towards the Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC). It is found that the rotation effects cannot always be neglected when the lens binaries are in the LMC disk or the SMC disk, i.e., when they are self-lensing. Therefore we suggest

Christopher J. Conselice

A summary of the highlights of the conference, &#34;Toward a New Millennium in Galaxy Morphology&#34; is presented. In this review, I cover the major topics addressed at the conference, including both the observational and theoretical frameworks suggested for understanding the morphology of galaxies.

M. Catelan

Deep HST photometry has recently been presented for the outer-halo globular clusters Palomar 4 and Eridanus. The new high-precision color-magnitude diagrams obtained for these globulars have allowed a measurement of their ages relative to M5 (NGC 5904), which is a well-observed, much closer cluster. Assuming that the globular clusters share the same chemical

Remi A. Cabanac, Valerie de Lapparent

The future Large Zenith Telescope Survey will provide a catalog of spectrophotometric energy distributions (40 filters) of ~10^6 objects. In this paper, we shows that the principal component analysis is efficient to separate stars, galaxies and QSOs. Realistic simulations are performed to assess quantitatively the efficiency of the method. Redshifts can be e

D. Fargion, L. Chiatti, A. Aiello

The inertial drag on Cooper pairs in a rotating rf-SQUID ring leads to an asymmetry in the Hamiltonian potential able to force the average magnetic field versus in the ring along the angular velocity one. This effect is a Sagnac signature of Cooper pairs at a quantum level and it may probe the fundamental quantum Mach principle within detectability levels.

Per Kraus

We study solutions corresponding to moving domain walls in the Randall-Sundrum universe. The bulk geometry is given by patching together black hole solutions in AdS$_5$, and the motion of the wall is determined from the junction equations. Observers on the wall interpret the motion as cosmological expansion or contraction. We describe the possible wall traje

B. Jensen, I. Brevik

It has been shown by Liberati et al. [quant-ph/9904013] that a dielectric medium with a time-dependent refractive index may produce photons. We point out that a free electric charge which interacts with such a medium will emit quantum mechanically modified transition radiation in which an arbitrary odd number of photons will be present. Excited atomic electr

Marcel Oliver, Steve Shkoller

We show that a certain class of vortex blob approximations for ideal hydrodynamics in two dimensions can be rigorously understood as solutions to the equations of second-grade non-Newtonian fluids with zero viscosity, and initial data in the space of Radon measures ${\mathcal M}({\mathbb R}^2)$. The solutions of this regularized PDE, also known as the averag

M. A. Malkov, P. H. Diamond, H. J. Voelk

There are two distinct regimes of the first order Fermi acceleration at shocks. The first is a linear (test particle) regime in which most of the shock energy goes into thermal and bulk motion of the plasma. The second is an efficient regime when it goes into accelerated particles. Although the transition region between them is narrow, we identify the factor

David Berenstein, Robert G. Leigh

We present a perturbative study of Ramond-Ramond backgrounds in the NSR formalism. We show how to perform sigma-model computations and discuss in detail the structure of the BRST charge and picture-changing operators. Contact terms play a vital role in the analysis. We also give evidence for a two loop non-renormalization theorem for the background beta func

Amine B. Hammou, Jose F. Morales

We express the infinite sum of D-fivebrane instanton corrections to ${\cal R}^2$ couplings in ${\cal N}=4$ type I string vacua, in terms of an elliptic index counting 1/2-BPS excitations in the effective $Sp(N)$ brane theory. We compute the index explicitly in the infrared, where the effective theory is argued to flow to an orbifold CFT. The form of the inst

Michael Praehofer, Herbert Spohn

For one-dimensional growth processes we consider the distribution of the height above a given point of the substrate and study its scale invariance in the limit of large times. We argue that for self-similar growth from a single seed the universal distribution is the Tracy-Widom distribution from the theory of random matrices and that for growth from a flat

Matthias Klein

It has been proposed that gauge and Kaehler anomalies in four-dimensional type IIB orientifolds are cancelled by a generalized Green-Schwarz mechanism involving exchange of twisted RR-fields. We explain how this can be understood using the well-known duality between linear and chiral multiplets. We find that all the twisted fields associated to the N=1 secto

M. Turatto, T. Suzuki, P. A. Mazzali, S. Benetti

The extraordinary SN 1997cy associated with GRB 970514 has been observed photometrically and spectroscopically for nearly 2 yr. At the time of discovery SN 1997cy was the brightest SN ever observed (Mv=<-20.1, v(hel)=19140 km/s, H_0=65 km/s/Mpc). Up to the last available observations (600 days after the GRB) the total time-integrated flux was equal to or lar

M. E. Zhitomirsky, T. M. Rice

We investigate the energetics of the electron-hole liquid in stoichiometric divalent metal hexaborides. The ground state energy of an electron-hole plasma is calculated using RPA and Hubbard schemes and compared to the binding energy of a single exciton. Intervalley scattering processes play an important role in increasing this binding energy and stabilizing

Giuliano Benenti, Xavier Waintal, Jean-Louis Pichard

The study of the ground state of spinless fermions in 2d disordered clusters (Phys. Rev. Lett. {\bf 83}, 1826 (1999)) has suggested the existence of a new quantum phase for intermediate Coulomb energy to kinetic energy ratios $r_s$. Exact diagonalization of the same small clusters show that its low energy excitations (quantum ergodicity above a few ``hexatic

T. Joseph W. Lazio, A. L. Fey, Brian Dennison

(Abridged) We report multi-epoch VLBI observations of the source PKS 1741-038 as it underwent an extreme scattering event. Observations at four epochs were obtained, and images were produced at three of these. During the event the source consisted of a dominant, compact component, essentially identical to the structure seen outside the event. However, the so

S. V. Mikhailov

An approach is elaborated for calculation of &#34;all loop&#34; contributions to the non-singlet evolution kernels from the diagrams with renormalon chain insertions. Closed expressions are obtained for sums of contributions to kernels $P(z)$ for the DGLAP equation and $V(x,y)$ for the &#34;nonforward&#34; ER-BL equation from these diagrams that dominate for

D. A. Frail, E. Waxman, S. R. Kulkarni

We report on the results of an extensive monitoring campaign of the radio afterglow of GRB 970508, lasting 450 days after the burst. The spectral and temporal radio behavior indicate that the fireball has undergone a transition to sub-relativistic expansion at t~100 days. This allows us to perform &#34;calorimetry&#34; of the explosion. The derived total ene

Minos Axenides, Stavros Komineas, Leandros Perivolaropoulos, Manolis Floratos

We use numerical simulations and semi-analytical methods to investigate the stability and the interactions of nontopological stationary qball solutions. In the context of a simple model we map the parameter sectors of stability for a single qball and verify the result using numerical simulations of time evolution. The system of two interacting qballs is also

C. L. Carilli, M. S. Yun

We derive the scatter in the relationship between redshift and radio-to-submm spectral index, alpha^{350}_{1.4}, using the observed spectral energy distributions of 17 low redshift star forming galaxies. A mean galaxy model is derived, along with the rms scatter in alpha^{350}_{1.4}. The scatter is roughly constant with redshift. Constant rms scatter, combin

Ihor A. Lubashevsky, Reinhard Mahnke

We discuss a phenomenological approach to the description of unstable vehicle motion on multilane highways that explains in a simple way the observed sequence of the phase transitions &#34;free flow -> synchronized motion -> jam&#34; as well as the hysteresis in the transition &#34;free flow <-> synchronized motion&#34;. We introduce a new variable called or

C. J. Fewster

Worldline quantum inequalities provide lower bounds on weighted averages of the renormalised energy density of a quantum field along the worldline of an observer. In the context of real, linear scalar field theory on an arbitrary globally hyperbolic spacetime, we establish a worldline quantum inequality on the normal ordered energy density, valid for arbitra

H. Jirari, H. Kröger, X. Q. Luo, K. J. M. Moriarty

We suggest a closed form expression for the path integral of quantum transition amplitudes. We introduce a quantum action with renormalized parameters. We present numerical results for the $V \sim x^{4}$ potential. The renormalized action is relevant for quantum chaos and quantum instantons.

E. Masso

We find the following improved laboratory bounds on the coupling of light pseudoscalars to protons and neutrons: $g_p^2/4π< 1.7 \times 10^{-9}$ and $g_n^2/4π< 6.8 \times 10^{-8}$. The limit on $g_p$ arises since a nonzero $g_p$ would induce a coupling of the pseudoscalar to two photons, which is limited by experiments studying laser beam propagation in magne

Kazumi Okuyama

The world-volume theory on a D-brane in a constant B-field background can be described by either commutative or noncommutative Yang-Mills theories. These two descriptions correspond to two different gauge fixing of the diffeomorphism on the brane. Comparing the boundary states in the two gauges, we derive a map between commutative and noncommutative gauge fi

C. R. Contaldi, R. Bean, J. Magueijo

We show that density fluctuations in standard inflationary scenarios may take the most general non-Gaussian distribution if the wave function of the Universe is not in the ground state. We adopt the Schrödinger picture to find a remarkable similarity between the most general inflaton wavefunction and the Edgeworth expansion used in probability theory. Hence

Dongsu Bak

A deformed Nahm equation for the BPS equation in the noncommutative N=4 supersymmetric U(2) Yang-Mills theory is obtained. Using this, we constructed explicitly a monopole solution of the noncommutative BPS equation to the linear order of the noncommutativity scale. We found that the leading order correction to the ordinary SU(2) monopole lies solely in the

M. D. Albrow, J. -P. Beaulieu, J. A. R. Caldwell, M. Dominik

We analyze PLANET collaboration data for MACHO 97-BLG-41, the only microlensing event observed to date in which the source transits two disjoint caustics. The PLANET data, consisting of 46 V-band and 325 I-band observations from five southern observatories, span a period from the initial alert until the end of the event. Our data are incompatible with a stat

Sergey Maksymenko

Let $M$ be a compact surface and $P$ be a one dimensional manifold without boundary, that is the line $\mathbb{R}^1$ or a circle $S^1$. The classification of path-components of the space of Morse maps from $M$ into $P$ was recently obtained by S. V. Matveev and V. V. Sharko for the case $P=\mathbb{R}$. For $P=S^1$ the classification was obtained by the autho

J. A. Sauls

These lecture notes provide an introduction to non-equilibrium superfluid 3He, with applications to high-frequency excitations, including aspects of symmetry breaking in 3He and its effects on collective mode dynamics. In 1957 Landau predicted that liquid 3He would support propagating shear waves at low temperatures, i.e. a transverse sound mode. Such waves

Andrew G. Cohen, David B. Kaplan

We show that gravitational effects of global cosmic 3-branes can be responsible for compactification from six to four space-time dimensions, naturally producing the observed hierarchy between electroweak and gravitational forces. The finite radius of the transverse dimensions follows from Einstein&#39;s equation, and is exponentially large compared with the

A. Ballesteros, O. Ragnisco

Two dimensional classical integrable systems and different integrable deformations for them are derived from phase space realizations of classical $sl(2)$ Poisson coalgebras and their $q-$deformed analogues. Generalizations of Morse, oscillator and centrifugal potentials are obtained. The N=2 Calogero system is shown to be $sl(2)$ coalgebra invariant and the

F. Musso, O. Ragnisco

A complete set of commuting observables for the Calogero-Gaudin system is diagonalized, and the explicit form of the corresponding eigenvalues and eigenfunctions is derived. We use a purely algebraic procedure exploiting the co-algebra invariance of the model; with the proper technical modifications this procedure can be applied to the $q-$deformed version o

Y. Ohta, K. M. Tamizhmani, B. Grammaticos, A. Ramani

We examine the validity of the results obtained with the singularity confinement integrability criterion in the case of discrete Painlevé equations. The method used is based on the requirement of non-exponential growth of the homogeneous degree of the iterate of the mapping. We show that when we start from an integrable autonomous mapping and deautonomise it

V. I. Man&#39;ko, G. Marmo, E. C. G. Sudarshan, F. Zaccaria

The need to retain the relative phases in quantum mechanics implies an addition law parametrized by a phase of two density operators required for the purification of a density matrix. This is shown with quantum tomography and the Wigner function. Entanglement is determined in terms of phase dependent multiplication.

Asher Peres

Popper conceived an experiment whose analysis led to a result that he deemed absurd. Popper wrote that his reasoning was based on the Copenhagen interpretation and therefore invalidated the latter. Actually, Popper&#39;s argument involves counterfactual reasoning and violates Bohr&#39;s complementarity principle. The absurdity of Popper&#39;s result only con

Sameen Ahmed Khan, Modesto Pusterla

An interpretation of the formation of halo in accelerators based on quantum-like theory by a diffraction model is given in terms of the transversal beam motion. Physical implications of the longitudinal dynamics are also examined.

Steven B. Lowen, Tsuyoshi Ozaki, Ehud Kaplan, Bahaa E. A. Saleh

We employ a number of statistical measures to characterize neural discharge activity in cat retinal ganglion cells (RGCs) and in their target lateral geniculate nucleus (LGN) neurons under various stimulus conditions, and we develop a new measure to examine correlations in fractal activity between spike-train pairs. In the absence of stimulation (i.e., in th

Ernst Karl Kunst

Herein it is shown that mass and time in the rest frame as well as relativistically enlarged mass and dilated time in the moving frame are of like origin. This implies that the former are generated by the movement of a fourth spatial dimension of matter relative to a four-dimensional manifold.

R. J. Furnstahl, James V. Steele, Negussie Tirfessa

An accurate description of nuclear matter starting from free-space nuclear forces has been an elusive goal. The complexity of the system makes approximations inevitable, so the challenge is to find a consistent truncation scheme with controlled errors. Nonperturbative effective field theories could be well suited for the task. Perturbative matching in a mode

M. Hauger, A. Honegger, J. Jourdan, G. Kubon

We have built a polarimeter in order to measure the electron beam polarization in hall C at JLAB. Using a superconducting solenoid to drive the pure-iron target foil into saturation, and a symmetrical setup to detect the Moller electrons in coincidence, we achieve an accuracy of <1%. This sets a new standard for Moller polarimeters.

A. V. Blinov, M. V. Chadeyeva, V. E. Grechko, V. F. Turov

The total and topological 4Hep cross sections as well as the cross sections of the separate 4Hep interaction channels and the differential cross sections of the elastic 4Hep scattering were measured using the 2m hydrogen bubble chamber exposed to a separated beam of alpha-particles from the ITEP synchrotron at 5 GeV/c (the kinetic energy of the initial proto

F. Gesztesy, B. Simon

We provide a new short proof of the following fact, first proved by one of us in 1998: If two Weyl-Titchmarsh m-functions, $m_j(z)$, of two Schrödinger operators $H_j = -\f{d^2}{dx^2} + q_j$, j=1,2 in $L^2 ((0,R))$, $0<R\leq \infty$, are exponentially close, that is, $|m_1(z)- m_2(z)| \underset{|z|\to\infty}{=} O(e^{-2\Ima (z^{1/2})a})$, 0<a<R, then $q_1 = q

S. V. Ludkovsky

Loop groups G as families of mappings of the complex manifold M into another complex manifold N preserving marked points $s_0\in M$ and $y_0\in N$ are investigated. Quasi-invariant measures $μ$ on G relative to dense subgroups $G&#39;$ are constructed. These measures are used for the studying of irreducible representations of such groups.

Ara Aleksanyan, Mihran Papikian

We consider the problem of finding the minimal number of points required to intersect all lines in an affine space over the finite field of order 3. We also consider the problem of finding the minimal number of points required to intersect all two dimensional affine subspaces in an affine space over the field of order 2.

Stephen F. Sawin

The quotient process of Müger and Bruguières is used to construct modular categories and TQFTs out of closed subsets of the Weyl alcove of a simple Lie algebra. In particular it is determined at which levels closed subsets associated to nonsimply-connected groups lead to TQFTs. Many of these TQFTs are shown to decompose into a tensor product of TQFTs coming

B. Eden, P. S. Howe, C. Schubert, E. Sokatchev

It is shown that certain extremal correlators in four-dimensional N=2 superconformal field theories (including N=4 super-Yang-Mills as a special case) have a free-field functional form. It is further argued that the coupling constant dependence receives no correction beyond the lowest order. These results hold for any finite value of N_c.

T. Gannon

We show that the $Y_{ab}^c$ of Pradisi-Sagnotti-Stanev are indeed integers, and we prove a conjecture of Borisov-Halpern-Schweigert. We indicate some of the special features which arise when the order of the modular matrix T is odd. Our arguments are general, applying to arbitrary ``parent&#39;&#39; RCFT assuming only that T has odd order.

Mary K. Gaillard

The on-shell regularization of the one-loop divergences of supergravity theories is generalized to include a dilaton of the type occurring in effective field theories derived from superstring theory, and the superfield structure of the one-loop corrections is given. Field theory anomalies and quantum contributions to soft supersymmetry breaking are discussed

Fotini Markopoulou, Lee Smolin

We propose a formulation of the holographic principle, suitable for a background independent quantum theory of cosmology. It is stated as a relationship between the flow of quantum information and the causal structure of a quantum spacetime. Screens are defined as sets of events at which the observables of a holographic cosmological theory may be measured, a

B. Carazza

This note looks at the possibility of a system of free particles presenting decoherence in the total momentum when tracing upon their relative momenta if we take into account a relativistic correction to the expression of the kinetic energy.

C. Adam, B. Muratori, C. Nash

One of the key properties of Dirac operators is the possibility of a degeneracy of zero modes. For the Abelian Dirac operator in three dimensions the question whether such multiple zero modes may exist has remained unanswered until now. Here we prove that the feature of zero mode degeneracy indeed occurs for the Abelian Dirac operator in three dimensions, by

V. Ch. Zhukovsky

Effective action of an SU(2) gauge model with a vortex in 4-dimensional space time is calculated in the 1-loop approximation. The minimum of the effective potential is found.

Zhe Chang, Han-Ying Guo

Two kinds of realizations of symmetry on classical domains or the Euclidean version of AdS space are used to study AdS/CFT correspondence. Mass of free particles is defined as an AdS group invariant, the Klein-Gordon and Dirac equations for relativistic particles in the AdS space are set up as a mimic in the case of Minkowskian space. The bulk-boundary propa

Karin Bautier

It is shown that the AdS_3 gravity action with boundary terms is non invariant under diffeomorphisms and that its Lie derivative has the form of the Weyl anomaly in two dimensions. This variation is compensated by a Weyl transformation of the boundary metric when the radial derivative of the metric on the boundary is expressed in terms of the stress tensor o

K. -I. Izawa

Nonlinear gauge theory is a gauge theory based on a nonlinear Lie algebra (finite W algebra) or a Poisson algebra, which yields a canonical star product for deformation quantization as a correlator on a disk. We pursue nontrivial deformation of topological gauge theory with conjugate scalars in two dimensions. This leads to two-dimensional nonlinear gauge th

V. V. Mkhitaryan, R. H. Poghossian, T. A. Sedrakyan

A perturbation theory for Massive Thirring Model (MTM) in radial quantization approach is developed. Investigation of the twisted sector in this theory allows us to calculate the vacuum expectation values of exponential fields $ exp iaphi (0) $ of the sine-Gordon theory in first order over Massive Thirring Models coupling constant. It appears that the appare

A. Pich

Precision measurements of electroweak observables provide stringent tests of the Standard Model structure and an accurate determination of its parameters. An overview of the present experimental status is presented.

G. L. Fogli, E. Lisi, D. Montanino, A. Palazzo

The Mikheyev-Smirnov-Wolfenstein (MSW) explanation of the solar neutrino problem is currently compatible with three distinct regions of the two-neutrino oscillation parameter space (delta m^2,sin^2 2theta). We focus on the region with the lowest value of delta m^2 (~10^{-7} eV^2), which implies significant Earth regeneration effects for low-energy solar neut

Yi-Bing Ding, Xue-Qian Li, Peng-Nian Shen

It would be interesting to investigate the accuracy of the results obtained in the variational method, because it is important for studying hadron spectra. One can define some criteria to judge the accuracy, or the quality of the trial function. We employ a simple potential form to check how accurate the variational results obtained by a single-parameter tri

M. Boglione, M. R. Pennington

Lee and Weingarten have recently criticized our calculation of quarkonium and glueball scalars as being &#34;incomplete&#34; and &#34;incorrect&#34;. Here we explain the relation of our calculations to full QCD.

M. Kuroda, D. Schildknecht

We review the results on representing the differential cross section for W-pair production, including W decay and hard-photon bremsstrahlung, in terms of a Born-form approximation of fairly simple analytic form.

Esteban Roulet

An elementary general overview of the neutrino physics and astrophysics is given. We start by a historical account of the development of our understanding of neutrinos and how they helped to unravel the structure of the Standard Model. We discuss why it is so important to establish if neutrinos are massive and we introduce the main scenarios to provide them

E. Ruiz Arriola

This research summarizes work done by myself (Nucl.Phys.{\bf A641} (1998)461), or in collaboration with R. M. Davidson (Phys.Lett.{\bf B348}(1995)163) and H. Weigel and L. Gamberg (Nucl.Phys.{\bf B560}(1999)xx). I will discuss several topics related with the computation of structure functions in the quark model in general and its perturbative evolution. In p

P. Y. Bertin, Y. Roblin, C. E. Hyde-Wright

We discuss the experimental issues confronting measurements of the Virtual Compton Scattering (VCS) reaction ep->ep gamma with electron beam energies 6-30 GeV. We specifically address the kinematics of Deeply Virtual Compton Scattering (Deep Inelastic Scattering, with coincident detection of the exclusive real photon nearly parallel to the virtual photon dir

G. Cvetic, D. Schildknecht, A. Shoshi

We review the generalized vector dominance (GVD) approach to DIS at small values of the scaling variable, x. In particular, we concentrate on a recent formulation of GVD that explicitly incorporates the configuration of the gamma^* -> q qbar transition and a QCD-inspired ansatz for the (qqbar)p scattering amplitude. The destructive interference, originally i

A. L. Kataev, G. Parente, A. V. Sidorov

The next-to-next-to-leading order (NNLO) QCD analysis of the experimental $xF_3$ structure function from CCFR data is performed. The theoretical uncertainties of the analysis are discussed.

R. Peschanski

the forward jet playing the role of a hard probe is analyzed in terms of QCD dipole (color-singlet q\bar q) configurations in the transverse position space. There are sizable differences with the analogous q\bar q configurations of a hard photon which may lead to significant phenomenological consequences on the analysis of hard processes using a forward jet

D. Jido, T. Hatsuda, T. Kunihiro

Baryon resonances with even and odd parity are collectively investigated from the viewpoint of chiral symmetry(ChS). We propose a quartet scheme where Delta&#39;s and N^*&#39;s with even and odd parity form a chiral multiplet. This scheme gives parameter-free constraints on the baryon masses in the quartet, which are consistent with observed masses with spin

Bo Andersson, Fredrik Soderberg

We will in this note show that it is possible to diagonalise the Lund Fragmentation Model. We show that the basic original result, the Lund Area law, can be factorised into a product of transition operators, each describing the production of a single particle and the two adjacent breakup points (vertex positions) of the string field. The transition operator

Han-xin He

The identical relations among the transverse parts of variant vertex functions are derived by computing the curl of the time-ordered products of three-point Green functions involving the vector, the axial-vector and the tensor current operators, respectively. These transverse relations are coupled each other. Combining these transverse relations with the nor

M. Faber, J. Greensite, S. Olejnik, D. Yamada

We argue that the ``vortex-finding&#39;&#39; property of maximal center gauge, i.e. the ability of this gauge to locate center vortices inserted by hand on any given lattice, is the key to its success in extracting the vortex content of thermalized lattice configurations. We explain how this property comes about, and why it is expected not only in maximal ce