June 1999 arXiv papers — page 13

K. Yoshizaki, A. Ono, N. Takigawa

We examine whether the self interaction correction method by Harrison, which does not introduce the spherical single particle density approximation to energy functional, can be applied to Na clusters. We show that it does not work well, especially, for large clusters, though it works well for atomic systems. We suggest that it is better to apply this method

Vasiliki Plerou, Luis A. Nunes Amaral, Parameswaran Gopikrishnan, Martin Meyer

There is nowadays considerable interest on ways to quantify the dynamics of research activities, in part due to recent changes in research and development (R&D) funding. Here, we seek to quantify and analyze university research activities, and compare their growth dynamics with those of business firms. Specifically, we analyze five distinct databases, the la

S. Vishveshwara, T. Senthil, Matthew P. A. Fisher

We propose a characterization of zero temperature phases in disordered superconductors on the basis of the nature of quasiparticle transport. In three dimensional systems, there are two distinct phases in close analogy to the distinction between normal metals and insulators: the superconducting "metal" with delocalized quasiparticle excitations and t

Rachel M. Quick, Sergei G. Sharapov

A quasi two-dimensional non-relativistic four-Fermi theory is studied at finite temperatures in the next-to-leading order approximation using the Coleman-Weinberg effective potential. The appearance of an imaginary part to the one-loop correction is discussed in the context of condensed matter theory where it is referred to as the Thouless criterion for supe

Donovan L. Domingue, William C. Keel, Stuart D. Ryder, Raymond E. White

The detailed distribution of dust in the disks of spiral galaxies is important to understanding the radiative transfer within disks, and to measuring overall dust masses if significant quantities of dust are either very opaque or very cold. We address this issue by comparing measures of dust absorption, using the galaxy-overlap technique in the optical, with

Lee Hartmann, Nuria Calvet, Lori Allen, Hua Chen

We report Hubble Space Telescope near-infrared NICMOS observations of a remarkable low-luminosity Class I (protostellar) source in the Taurus Molecular Cloud. IRAS 04325+2402 exhibits a complex bipolar scattered light nebula. The central continuum source is resolved and may be multiple, or may be crossed by a small dust lane. Complex arcs seen in scattered l

Anatoli Vankov

An open (having no physical boundaries) baryon symmetric system is considered in a flat space-time. We assume that a space is uniformly filled with electromagnetic radiation and material objects, and the system is isotropic in any inertial reference frame. It means that a coordinate-momentum distribution of radiation and material objects does not depend on a

C. Chevalier, S. A. Ilovaisky, P. Leisy, F. Patat

Direct I and V-band imaging of Aql X-1 in quiescence and during outburst maximum shows that the true optical counterpart is the interloper located 0.48" West of the previously known star. We find for the new counterpart V = 21.6 and V-I = 2.2 in quiescence, when its contribution to the total light was 12% in V and 22% in I. Analysis of this photometry an

M. Rowan-Robinson

Determinations of the main cosmological parameters are reviewed and the implications for cold dark matter discussed. There is no longer an age problem for an $Ω_o = 1, Λ= 0$ model and, if anything, there is now an age problem for low $Ω_o, Λ> 0$ models. Large scale structure and CMB fluctuation data are best fitted by a mixed dark matter $Ω_o$ = 1 universe.

P. A. James, C. Bate, M. Wells, G. S. Wright

We present near-IR K-band imaging and spectroscopy of a sample of galaxy mergers, which we use to derive light profile indices, absolute magnitudes and central velocity dispersions. It is found that the light distributions of mergers more nearly resemble those of ellipticals than of bulges, but that the mergers lie well away from the Fundamental Plane define

Chris Shrader, Lev Titarchuk

We offer a brief description of the bulk-motion Comptonization (BMC) model for accretion onto black holes, illustrated by its application to observational data for LMC X-1, and Nova Muscae 1991. We then extract some physical parameters of these systems from observables (within the context of the BMC model}, drawing from results on GRO J1655-40, for which we

M. Turler, T. J. -L. Courvoisier, S. Paltani

We present a new approach to derive the observed properties of synchrotron outbursts in relativistic jets. The idea is to use the very well sampled submillimetre-to-radio long-term light curves of 3C 273 to extract the spectral and temporal evolution of a typical outburst. The method consists in a decomposition of these light curves into a series of twelve s

M. Rowan-Robinson, S. Oliver, A. Efstathiou, C. Gruppioni

The European Large Area ISO Survey (ELAIS) has surveyed 12 square degrees of the sky at 15 and 90 microns, and subsets of this area at 6.75 and 175 microns, using the Infrared Space Observatory (ISO). This project was the largest single open time programme executed by ISO, taking 375 hours of data. A preliminary catalogue of more than 1000 galaxies has been

Craig L. Sarazin

Models for the integrated relativistic electron population in clusters of galaxies are presented. The results depend on the history of electron acceleration in the cluster. If there is no present particle acceleration or other sources, then no high energy electrons (gamma >~ 300, E >~ 150 MeV) should be present due to inverse Compton (IC) losses. High energy

Joop Schaye, Tom Theuns, Anthony Leonard, George Efstathiou

(Abridged) Numerical simulations indicate that the intergalactic medium (IGM) responsible for the low column density Lyman-alpha forest follows a well defined temperature-density relation. We demonstrate that such an equation of state results in a cutoff in the distribution of line widths (b-parameters) as a function of column density (N) for the low column

L. Piersanti, S. Cassisi, I. Iben, A. Tornambe'

Hydrogen-rich matter has been added to a CO white dwarf of initial mass 0.516 \msun at the rates $10^{-8}$ and $2\times 10^{-8}$ \msun \yrm1, and results are compared with those for a white dwarf of the same initial mass which accretes pure helium at the same rates. For the chosen accretion rates, hydrogen burns in a series of recurrent mild flashes and the

G. Piotto, M. Zoccali, I. R. King, S. G. Djorgovski C. Sosin

We present observations of the center of the Galactic globular cluster NGC 6273, obtained with the HST/WFPC2 camera as part of the snapshot program GO-7470. A B, V color-magnitude diagram (CMD) for ~28,000 stars is presented and discussed. The most prominent feature of the CMD, identified for the first time in this paper, is the extended horizontal branch bl

Davide Lazzati, Gabriele Ghisellini, Sergio Campana

The discovery of a powerful and transient iron line feature in the X-ray afterglow spectrum of GRB 970508 and GRB 970828, if confirmed, would be a major breakthrough for understanding the nature the progenitor of gamma-ray bursts. We show that a large mass of iron very close to the burster is necessary to produce the emission line. This in itself strongly li

Roberto Soria, Kinwah Wu, Duncan Galloway

We carried out I, R, V and B photometric observations of the neutron star X-ray binary RXTE J2123-058 shortly after the end of the X-ray outburst in mid-1998. We adopt the low mass binary model to interpret our observations. After folding our data on the 0.24821-d orbital period, and correcting for the steady brightness decline following the outburst, we obs

C. Arlandini, F. Kaeppeler, K. Wisshak, R. Gallino

The recently improved information on the stellar (n,gamma) cross sections of neutron-magic nuclei at N = 82, and in particular of 142Nd, turned out to represent a sensitive test for models of s-process nucleosynthesis. While these data were found to be incompatible with the classical approach based on an exponential distribution of neutron exposures, they pr

K. S. Cheng, Y. Lu

We suggest that an extreme Kerr black hole with a mass $\sim 10^6M_\odot$, a dimensionless angular momentum $A\sim 1$ and a marginal stable orbital radius $r_{ms}\sim 3r_s\sim 10^{12}M_6 cm$ located in a normal galaxy, may produced a Gamma-ray Burst by capturing and disrupting a star. During this period, a transient accretion disk is formed and a strong tran

M. Matsuura, I. Yamamura, H. Murakami, M. M. Freund

The spectrometers onboard the Infrared Telescope in Space (IRTS) reveal water vapor absorption in early M-type stars, as early as M2. Previous observations detected H_2O vapor absorption only in stars later than M6, with the exception of the recent detection of H_2O in beta Peg (M2.5 II-III). In our sample of 108 stars, 67 stars have spectral types earlier t

Peter Erwin, Linda S. Sparke

We present an analysis of ground-based and HST images of three early-type barred galaxies. The first, NGC 2681, may be the clearest example yet of a galaxy with three concentric bars. The two other galaxies were previously suggested as triple-barred. Our analysis shows that while NGC 3945 is probably double-barred, NGC 4371 has only one bar; but both have in

Palash B. Pal

I discuss some compelling suggestions about particles which could be the dark matter in the universe, with special attention to experimental searches for them.

Stuart Bowyer, Thomas Berghoefer, Eric Korpela

Lieu, Mittaz, Bonamente, Durret and Kaastra have provided a document which claims to rebut the finding by Bowyer, Berghoefer and Korpela presented at the Ringburg Workshop (April 1999) that excess EUV emission detected in some clusters of galaxies is an artifact of the background subtraction employed. We provide here a response to their claims.

M. Hilke, D. Shahar, S. H. Song, D. C. Tsui

We experimentally study the phase diagram of the integer quantized Hall effect, as a function of density and magnetic field. We used a two dimensional hole system confined in a Ge/SiGe quantum well, where all energy levels are resolved, because the Zeeman splitting is comparable to the cyclotron energy. At low fields and close to the quantum Hall liquid-to-i

Shoji Hashimoto, Aida X. El-Khadra, Andreas S. Kronfeld, Paul B. Mackenzie

A lattice QCD calculation of the $\bar{B}\to Dl\barν$ decay form factors is presented. We obtain the value of the form factor $h_+(w)$ at the zero-recoil limit $w=1$ with high precision by considering a ratio of correlation functions in which the bulk of the uncertainties cancels. The other form factor $h_-(w)$ is calculated, for small recoil momenta, from a

Ingo Peschel, Ming-Chiang Chung

We consider chains with an optical phonon spectrum and study the reduced density matrices which occur in density-matrix renormalization group (DMRG) calculations. Both for one site and for half of the chain, these are found to be exponentials of bosonic operators. Their spectra, which are correspondingly exponential, are determined and discussed. The results

Paul H. Frampton, Sheldon L. Glashow

Working in the framework of three chiral neutrinos with Majorana masses, we investigate a scenario first realized in an explicit model by Zee: that the neutrino mass matrix is strictly off-diagonal in the flavor basis, with all its diagonal entries precisely zero. This CP-conserving ansatz leads to two relations among the three mixing angles $(θ_1, θ_2, θ_3)

Bruce Allen, Eanna Flanagan, Maria Alessandra Papa

Grishchuk has shown that the stochastic background of gravitational waves produced by an inflationary phase in the early Universe has an unusual property: it is not a stationary Gaussian random process. Due to squeezing, the phases of the different waves are correlated in a deterministic way, arising from the process of parametric amplification that created

Jody Trout

Let $A$ be a graded C*-algebra. We characterize Kasparov's K-theory group $\hat{K}_0(A)$ in terms of graded *-homomorphisms by proving a general converse to the functional calculus theorem for self-adjoint regular operators on graded Hilbert modules. An application to the index theory of elliptic differential operators on smooth closed manifolds and asym

MiniMax Collaboration, T. C. Brooks, M. E. Convery, W. L. Davis

We present results from MiniMax (Fermilab T-864), a small test/experiment at the Tevatron designed to search for the production of disoriented chiral condensate (DCC) in $p - \bar p$ collisions at $\sqrt{s} = 1.8$ TeV in the forward direction, $\sim 3.4 < η< \sim 4.2$. Data, consisting of $1.3 \times 10^6$ events, are analyzed using the robust observables de

M. Kollar, D. Vollhardt

The high-precision data for the specific heat C_{V}(T,V) of normal-liquid Helium-3 obtained by Greywall, taken together with the molar volume V(T_0,P) at one temperature T_0, are shown to contain the complete thermodynamic information about this phase in zero magnetic field. This enables us to calculate the T and P dependence of all equilibrium properties of

David Garfinkle

This paper considers metrics whose curvature tensor makes sense as a distribution. A class of such metrics, the regular metrics, was defined and studied by Geroch and Traschen. Here, we generalize their definition to form a wider class: semi-regular metrics. We then examine in detail two metrics that are semi-regular but not regular: (i) Minkowski spacetime

Seth A. Major

The Hamiltonian of a gravitational system defined in a region with boundary is quantized. The classical Hamiltonian, and starting point for the regularization, is required by functional differentiablity of the Hamiltonian constraint. The boundary term is the quasilocal energy of the system and becomes the ADM mass in asymptopia. The quantization is carried o

Hsien-Hung Shih, Shih-Chang Lee, Hsiang-nan Li

We develop perturbative QCD factorization theorem for the semileptonic heavy baryon decay $Λ_b \to Λ_c l\barν$, whose form factors are expressed as the convolutions of hard $b$ quark decay amplitudes with universal $Λ_b$ and $Λ_c$ baryon wave functions. Large logarithmic corrections are organized to all orders by the Sudakov resummation, which renders pertur

V. S. Babichenko, Yu. Kagan

It is shown that the drastic distinction in the rotational structure of molecules in the He4 and He3 liquids observed in [1] is due to the difference in the spectral density of excitations regardless of the hydrodynamic properties. The large width of rotational levels in the He3 is determined by particle-hole excitations whereas the small density of phonon e

Sergei M. Sergeev

We investigate some classical evolution model in the discrete 2+1 space-time. A map, giving an one-step time evolution, may be derived as the compatibility condition for some systems of linear equations for a set of auxiliary linear variables. Dynamical variables for the evolution model are the coefficients of these systems of linear equations. Determinant o

Soheila Gharanfoli, Amir H. Abbassi

1- It is shown that the upper bound for $α$ in the general solutions of spherically symmetric vacuum field equations(gr-qc/9812081,$Λ$=0) is nearly 10^3.This has been obtained by comparing the theoretical prediction for bending of light and precession of perihelia with observation. For a significant range of possible values of$α$ ($α$ >2) the metric is free

Gerald V. Dunne, Kumar Rao

We perform a precise analytic test of the instanton approximation by comparing the exact band spectrum of the periodic Lamé potential to the tight-binding, instanton and WKB approximations. The instanton result gives the correct leading behavior in the semiclassical limit, while the tight-binding approximation does even better. WKB is off by an overall facto

Machiko Hatsuda, Kiyoshi Kamimura, Sayaka Sekiya

We find general non-linear lagrangians of a U(1) field invariant under electric-magnetic duality. They are characterized by an arbitrary function and go to the Maxwell theory in the weak field limit. We give some explicit examples which are generalizations of the Born-Infeld theory.

G. C. Branco, M. N. Rebelo, J. I. Silva-Marcos

We analyse, within the framework of universal strength for Yukawa couplings (USY), various structures for the Dirac and Majorana neutrino mass matrices giving rise, through the see-saw mechanism, to a degenerate mass spectrum. A specific USY ansatz is presented for the charged lepton and neutrino effective mass matrix, leading to quasi-degenerate neutrinos a

Ch. Brouder

The solution of some equations involving functional derivatives is given as a series indexed by planar binary trees. The terms of the series are given by an explicit recursive formula. Some algebraic properties of these series are investigated. Several examples are treated in the case of quantum electrodynamics: the complete fermion and photon propagators, t

Ignatios Antoniadis, Guillaume Ovarlez

In these lectures we give a brief introduction to perturbative and non-perturbative string theory. The outline is the following: 1. Introduction to perturbative string theory 1.1 From point particle to extended objects 1.2 Free closed and open string spectrum 1.3 Compactification on a circle and T-duality 1.4 The Superstring: type IIA and IIB 1.5 Heterotic s

Ashok Goyal, Meenu Dahiya

We study the chiral symmetry structure in a linear sigma model with fermions in the presence of an external, uniform magnetic field in the &#39;effective potential&#39; approach at the one loop level. We also study the chiral phase transition as a function of density in the core of magnetized neutron stars.

Satoru Muto, Hideo Aoki

Molecular dynamics simulation is used to investigate the crystallization of a classical two-dimensional electron system, in which electrons interact with the Coulomb repulsion. From the positional and the orientational correlation functions, we have found an indication that the solid phase has a quasi-long-range (power-law correlated) positional order and a

T. Asaka, M. Kawasaki, Masahide Yamaguchi

We study the initial value problem of new inflation models in the scheme of supergravity. We find that an inflaton generally acquires a mass of the order of the Hubble parameter via gravitationally suppressed interactions with particles in the thermal bath of the universe. This additional mass term stabilizes dynamically the inflaton at the local maximum of

Julian Lee, Sangmin Lee

We compute the Kaluza-Klein mass spectrum of the D=11 supergravity compactified on AdS2 x S2 x T7 and arrange it into representations of the SU(1,1|2) superconformal algebra. This geometry arises in M theory as the near horizon limit of a D=4 extremal black-hole constructed by wrapping four groups of M-branes along the T7. Via AdS/CFT correspondence, our res

Charles Francis

It is argued that the orthodox interpretation of quantum mechanics is in conflict with the objective existence of space-time, and suggested that kets are labels which name real states of matter but do not directly describe them. Position is a relationship between particles which necessarily contains uncertainty. The principle of superposition is seen as a de

Qiang-Hua Wang, Z. D. Wang, Q. Li

A Ginzburg-Landau theory is developed for unconventional superconductors with the three relevant singlet pairing channels. Various consequences of the sub-dominant channels (i.e., s- and d_{xy}-channels) are examined in detail. (1) In the case of a d_{x^2-y^2}+is-wave superconductor, The structure of a single vortex above and below T_{DS} is four-fold and tw

G. Falqui, F. Magri, G. Tondo

We discuss the Boussinesq system with $t_5$ stationary, within a general framework for the analysis of stationary flows of n-Gel&#39;fand-Dickey hierarchies. We show how a careful use of its bihamiltonian structure can be used to provide a set of separation coordinates for the corresponding Hamilton--Jacobi equations.

James D. E. Grant

We consider some natural connections which arise between right-flat (p, q) paraconformal structures and integrable systems. We find that such systems may be formulated in Lax form, with a &#34;Lax p-tuple&#34; of linear differential operators, depending a spectral parameter which lives in (q-1)-dimensional complex projective space. Generally, the differentia

Jan Perina

The dependence of one- and two-photon characteristics of pulsed entangled two-photon fields generated in spontaneous parametric down-conversion on the pump-pulse properties (shape of the pump-pulse spectrum and its internal structure) is examined. It is shown that entangled two-photon fields with defined properties can be generated. A general relation betwee

N. V. Vitanov, B. W. Shore, R. G. Unanyan, K. Bergmann

We propose a simple method for measuring the populations and the relative phase in a coherent superposition of two atomic states. The method is based on coupling the two states to a third common (excited) state by means of two laser pulses, and measuring the total fluorescence from the third state for several choices of the excitation pulses.

N. V. Vitanov

This paper shows that under certain symmetry conditions the probability of remaining in the initial state (the probability of no transition) in a chainwise-connected multistate system driven by two or more delayed laser pulses does not depend on the pulse order.

N. Gisin, H. Zbinden

All experimental tests of the violation of Bell&#39;s inequality suffer from some loopholes. We show that the locality loophole is not independent of the detection loophole: in experiments using low efficient detectors, the locality loophole can be closed equivalently using active or passive switches.

M. Abolhasani, M. Golshani

Recently, people have caculated tunneling&#39;s characteristic times within Bohmian mechanics. Contrary to some characteristic times defined within the framework of the standard interpretation of quantum mechanics, these have reasonable values. Here, we introduce one of available definitions for tunnelling&#39;s characteristic times within the standard inter

Roland Faller, Heiko Schmitz, Oliver Biermann, Florian Müller-Plathe

We demonstrate an automatic method of force field development for molecular simulations. Parameter tuning is taken as an optimization problem in many dimensions. The parameters are automatically adapted to reproduce known experimental data such as the density and the heat of vaporization. Our method is more systematic than guessing parameters and, at the sam

J. L. Friar, U. van Kolck

Charge-independence breaking due to the pion-mass difference in the (chiral) two-pion-exchange nucleon-nucleon force is investigated. A general argument based on symmetries is presented that relates the charge-symmetric part of that force to the proton-proton case. The static potential linear in that mass difference is worked out as an explicit example by me

Kyrill A. Bugaev

We have formulated a self-consistent model of freeze-out on an arbitrary hypersurface. It conserves energy and momentum across the discontinuity between ideal fluid and the gas of free particles. Energy and momentum of those free particles have non-equilibrium values that could be a signal for the formation of hot and dense matter in heavy ion collisions.

R. Bijker, A. Frank, S. Pittel

Recent calculations using random two-body interactions showed a preponderance of J(P)=0(+) ground states, despite the fact that there is no strong pairing character in the force. We carry out an analysis of a system of identical particles occupying orbits with j=1/2, 3/2 and 5/2 and discuss some general features of the spectra derived from random two-body in

Matthias Lutz

We apply the relativistic chiral Lagrangian to the nuclear equation of state. An effective chiral power expansion scheme, which is constructed to work around nuclear saturation density, is presented. The leading and subleading terms are evaluated and are shown to provide an equation of state with excellent saturation properties. Our saturation mechanism is f

S. Frankel

We return to further examination of the need for the existence of magnetic monopoles based on the decades old derivation [Sherman Frankel, Amer. Jour. of Physics, 44, 7, 683-6 1976], of both the monopole-charge force, vec(F) = eg(vec(r) * vec(v)/c)/r^3, as well as the Dirac angular momentum, vec(l_f) = eg hat(r), from P and T conservation alone, without any

Makoto Oka, Kenji Sasaki, Takashi Inoue

Nonmesonic decays of $Λ$ in nuclear medium and light hypernuclei are studied by using the $ΛN \to NN$ weak transition potential derived from the meson exchange mechanism and the direct quark mechanism. The long range part of the transition potential is described by exchanges of the pseudoscalar mesons ($π$, $K$, $η$), while the vector mesons ($ρ$, $ω$, $K^\a

Makoto Oka

The weak decays of hyperons and hypernuclei are studied from the chiral symmetry viewpoint. The soft pion relations are useful in understanding the isospin properties of the weak hyperon decays. Recent development on the short-range part of the $\Lam N\to NN$ weak transitions shows fairly good account of the weak decays of hypernuclei, though it fails to exp

Peter R. Bending

We present a method for computing the Mordell-Weil rank of the jacobian of a curve of genus 2 with multiplication by a square root of 2, based on descent via isogenies of degree 2, and apply it to a family of curves.

Alexander I. Bobenko, Yuri B. Suris

A discrete version of Lagrangian reduction is developed in the context of discrete time Lagrangian systems on $G\times G$, where $G$ is a Lie group. We consider the case when the Lagrange function is invariant with respect to the action of an isotropy subgroup of a fixed element in the representation space of $G$. In this context the reduction of the discret

Denis V. Juriev

This short note is devoted to the unraveling of the hidden interactivity of ordinary games which is an artefact of predictions of the behaviour of other players by the fixed player and describes deviations of their real behaviour from such predictions. A method to improve the predictions is proposed. Applications to the strategical analysis of interactive ga

Jean Paul Dufour, Yasuhiro Kurokawa

We show that the topological classification and the smooth classification are generically the same for certain families of plane curves in a semi-local case(the double local case). Especially we give the normal form of transversely jointed two families of plane curves with second order contact at the envelope.

Julien Bichon

We describe a universal factorization for a functor with values in finite-dimensional measured algebras. More precisely we contruct the quantum automorphism group of this functor. This general recontruction result allows us to recapture a finite-dimensional Hopf algebra from the category of finite-dimensional measured comodule algebras.

Ilse Fischer

We compute the number of rhombus tilings of a hexagon with side lengths a,b,c,a,b,c which contain the central rhombus and the number of rhombus tilings of a hexagon with side lengths a,b,c,a,b,c which contain the `almost central` rhombus above the centre.

Cezary Juszczak

The co-Lie structures compatible with the osp(2|2) Lie super algebra structure are investigated and found to be all of coboundary type. The corresponding classical r-matrices are classified into several disjoint families. The osp(1|2)+u(1) Lie super-bialgebras are also classified.

Toshiki Nakashima

We review the polyhedral realizations of crystal bases in the former half and in the latter half, we introduce braid-type isomorphisms for some rank 2 finite type crystals. Using this isomorphisms, for semi-simple Lie algebra we can show that polyhedral realizations can be obtained in the lattice of finite rank which coincides with the length of the longest

Piet Claus, J. Rahmfeld, Yonatan Zunger

The SO(4,2) isometries of AdS_5 are realized non-linearly on its horospherical coordinates (x^m,ρ). On the other hand, Penrose twistors have long been known to linearly realize these symmetries on 4-dimensional Minkowski space, the boundary of AdS_5, parametrized by x^m. Here we extend the twistor construction and define a pair of twistors, allowing us to in

Hatem Widyan, A. Mukherjee, N. Panchapakesan, R. P. Saxena

The nature of the transition from the quantum tunneling regime at low temperatures to the thermal hopping regime at high temperatures is investigated analytically in scalar field theory. An analytical bounce solution is presented, which reproduces the action in the thin-wall as well as thick-wall limits. The transition is first order for the case of a thin w

L. O&#39;Raifeartaigh, V. V. Sreedhar

The origin of the rather mysterious duality symmetry found in quantum Liouville theory is investigated by considering the Liouville theory as the reduction of a WZW-like theory in which the form of the potential for the Cartan field is not fixed a priori. It is shown that in the classical theory conformal invariance places no condition on the form of the pot

Jean Zinn-Justin

The evolution of ideas which has led from the first proofs of the renormalizability of non-abelian gauge theories, based on Slavnov--Taylor identities, to the modern proof based on the BRS symmetry and the master equation is recalled. This lecture has been delivered at the {\bf Symposium in the Honour of Professor C. N. Yang}, Stony-Brook, May 21-22 1999.

Paul Fendley

Thermodynamic Bethe ansatz equations are coupled non-linear integral equations which appear frequently when solving integrable models. Those associated with models with N=2 supersymmetry can be related to differential equations, among them Painleve III and the Toda hierarchy. In the simplest such case the massless limit of these non-linear integral equations

Justin R. David, Gautam Mandal, Sachindeo Vaidya, Spenta R. Wadia

We discuss, in terms of the AdS_3-CFT_2 correspondence, a one-parameter family of (asymptotically AdS_3) conical geometries which are generated by point masses and interpolate between AdS_3 and BTZ spacetimes. We show that these correspond to spectral flow in N= (4,4) SCFT_2 which interpolate between NS and R sectors. Our method involves representing the con

V. Azcoiti, A. Galante

Under very general assumptions we show that Vafa-Witten theorem on vector symmetries in vector-like theories can be extended to some physically relevant gauge theories with non-positive definite integration measure as QCD with a theta-vacuum term.

Jaydeep Majumder, Ashoke Sen

In the orbifold limit of K3, one can give exact conformal field theory description of D-branes wrapped on certain non-supersymmetric cycles of K3. We study the effect of switching on the `non-geometric blow up modes&#39; corresponding to anti-symmetric tensor gauge field flux through the 2-cycles on these D-branes. Working to first order in the blow up param

V. N. Plechko

The notion of the integral over the anticommuting Grassmann variables is applied to analyze the fermionic structure of the 2D Ising model with quenched site dilution. In the $N$-replica scheme, the model is explicitly reformulated as a theory of interacting fermions on a lattice. For weak dilution, the continuum-limit approximation implies the log-log singul

H. Nicolai

Invited talk at the conference &#34;Fundamental Interactions: From Symmetries to Black Holes&#34; in honor of Francois Englert, 24 - 27 March, Universite Libre de Bruxelles, Belgium

Oktay K. Pashaev, Jyh-Hao Lee

The self-dual Chern-Simons solitons under the influence of the quantum potential are considered. The single-valuedness condition for an arbitrary integer number $N \ge 0$ of solitons leads to quantization of Chern-Simons coupling constant $κ= m {e^{2} \over g}$, and the integer strength of quantum potential $s = 1 - m^{2}$. As we show, the Jackiw-Pi model co

J. W. F. Valle

Theory suggests the existence of neutrino masses, but little more. Facts are coming close to reveal our fantasy: solar and atmospheric neutrino data strongly indicate the need for neutrino conversions, while LSND provides an intriguing hint. The simplest ways to reconcile these data in terms of neutrino oscillations invoke a light sterile neutrino in additio

Dario Sassi Thober

The classical electron is presented as made up of an electric charge and two Dirac monopoles of opposite charge performing a magnetic dipole. It is discussed that a valid variational principle for this system can be defined. The Dirac quantization condition for charges can be derived in Quantum Electrodynamics as monopoles are properly defined in the structu

Shaaban Khalil, Tatsuo Kobayashi

We study contributions of supersymmetric CP phases to the CP violation $ε&#39;/ε$ in models with asymmetric $A$-matrices. We consider asymmetric $A$-matrices, which are obtained from string-inspired supergravity. We show that a certain type of asymmetry of $A$-matrices enhances supersymmetric contributions to the CP violation $ε&#39;/ε$ and the supersymmetri

M. Benayoun

We present a VMD based model aiming to describe all radiative decays of light mesons. We show that the SU(3) breaking mechanism proposed by Bando, Kugo and Yamawaki (BKY), supplemented by nonet symmetry breaking in the pseudoscalar sector are sufficient to provide a nice description of all data, except the charged K* radiative width. It is also shown that no

M. K. Volkov, V. L. Yudichev

A chiral Lagrangian containing, besides the usual meson fields, their first radial excitations is constructed. The Lagrangian is derived by bosonization of a Nambu--Jona-Lasinio (NJL) type quark model with separable nonlocal interactions. The nonlocality is described by form factors corresponding to 3-dimensional excited state wave functions. The spontaneous

I. P. Lokhtin, L. I. Sarycheva, A. M. Snigirev

Basing on model concepts we research the monojet-to-dijet ratio as a function of the jet energy detection threshold in ultrarelativistic collisions of nuclei. We provide an comparative analysis of the contribution to monojet yield from gluon radiation before initial hard parton-parton scattering and from non-symmetric dijet energy losses in quark-gluon plasm

T. Asaka, K. Hamaguchi, M. Kawasaki, T. Yanagida

We study a leptogenesis via decays of heavy Majorana neutrinos produced non-thermally in inflaton decays. We find that this scenario is fully consistent with existing supersymmetric inflation models such as for topological or for hybrid inflation and the Froggatt-Nielsen mechanism generating hierarchies in quark and lepton mass matrices. The reheating temper

Guang-jiong Ni, Guo-hong Yang, Rong-tang Fu, Haibin Wang

Based on a simple but effective regularization-renormalization method (RRM), the running coupling constants (RCC) of fermions with masses in quantum electrodynamics (QED) and quantum chromodynamics (QCD) are calculated by renormalization group equation (RGE). Starting at Q=0 ($Q$ being the momentum transfer), the RCC in QED increases with the increase of $Q$

Kiwoon Choi, Hyung Do Kim

We introduce a new confining force (μ-color) at TeV scale to dynamically generate a supersymmetry preserving mass scale which would replace the μparameter in the minimal supersymmetric standard model (MSSM). We discuss the Higgs phenomenology and also the pattern of soft supersymmetry breaking parameters allowing the correct electroweak symmetry breaking wit

M. Carena, J. Ellis, S. Lola, C. E. M. Wagner

In the light of the gathering evidence for $ν_μ-ν_τ$ neutrino oscillations, coming in particular from the Super-Kamiokande data on atmospheric neutrinos, we re-analyze the unification of gauge and Yukawa couplings within the minimal supersymmetric extension of the Standard Model (MSSM). Guided by a range of different grand-unified models, we stress the relev

Ambar Ghosal

We demonstrate that an $SU(2)_L\times U(1)_Y$ model with extended Higgs sector gives rise to bi-maximal neutrino mixing through the incorporation of SO(3) flavour symmetry and discrete symmetry. The neutrino and the charged lepton masses are generated due to higher dimensional terms. The hierarchical structures of neutrinos and charged leptons are obtained d

Mairi Sakellariadou, Nikos Tetradis

Within the context of supersymmetric hybrid inflation, we study a multiple-stage inflationary scenario that can generate a primordial spectrum of adiabatic density perturbations with a break at $k_b \simeq 0.05 h Mpc^{-1}$. The presence of such a break is supported by the APM galaxy survey data. We consider a specific model within this scenario and confront

Paul R. Anderson, Wayne Eaker

An improved method is given for the computation of the stress-energy tensor of a quantized scalar field using adiabatic regularization. The method works for fields with arbitrary mass and curvature coupling in Robertson-Walker spacetimes and is particularly useful for spacetimes with compact spatial sections. For massless fields it yields an analytic approxi

S. Capozziello, G. Lambiase, H. -J. Schmidt

We study extended theories of gravity where nonminimal derivative couplings of the form $R^{kl}ϕ_{, k}ϕ_{, l}$ are present in the Lagrangian. We show how and why the other couplings of similar structure may be ruled out and then deduce the field equations and the related cosmological models. Finally, we get inflationary solutions which do follow neither from

S. Yazadjiev

Classes of exact static solutions in four-dimensional Einstein-Maxwell-Dilaton gravity are found. Besides of the well-known solutions previously found in the literature, new solutions are presented.It&#39;s shown that spherically symmetric solutions, except the case of charged dilaton black hole, represent globally naked strong curvature singularities.

Takeshi Shimomura, Shinji Mukohyama

We calculate the net change in generalized entropy occurring when one carries out the gedanken experiment in which a box initially containing energy $E$, entropy $S$ and charge $Q$ is lowered adiabatically toward a Reissner-Nordström black hole and then dropped in. This is an extension of the work of Unruh-Wald to a charged system (the contents of the box po