June 1999 arXiv papers — page 16

L. Bellon, S. Ciliberto, C. Laroche

Low frequency dielectric measurements on plexiglass (PMMA) show that cooling and heating the sample at constant rate give an hysteretic dependence on temperature of the dielectric constant $ε$. A temporary stop of cooling produces a downward relaxation of $ε$. Two main features are observed i) when cooling is resumed $ε$ goes back to the values obtained with

Kent A. Peacock, Brian S. Hepburn

Many authors state that quantum nonlocality could not involve any controllable superluminal transmission of momentum-energy, signals, or information. We claim that most or all no-signalling proofs to date are question-begging, in that they depend upon assumptions about the locality of the measurement process that needed to be established in the first place.

Asher Peres

This paper has been withdrawn because it is superseded by quant-ph/9905084 "Bayesian analysis of Bell inequalities.

C. R. Mirasso, G. H. M. van Tartwijk, E. Hernandez-Garcia, D. Lenstra

We report detailed measurements of the pump-current dependency of the self-pulsating frequency of semiconductor CD lasers. A distinct kink in this dependence is found and explained using rate-equation model. The kink denotes a transition between a region where the self-pulsations are weakly sustained relaxation oscillations and a region where Q-switching tak

Fuqiang Wang

We review the experimental results on strangeness and antibaryon production in heavy-ion collisions at the AGS and SPS. We argue that the observed enhancement in kaon production at the AGS is consistent with hadronic description, while the multistrange baryon and antibaryon results at the SPS may need physics beyond hadronic nature. We call the need for meas

A. Dimca, F. Maaref, C. Sabbah, M. Saito

Using local cohomology and algebraic D-Modules, we generalize a comparison theorem between relative de Rham cohomology and Dwork cohomology due to N. Katz, A. Adolphson and S. Sperber.

Jintai Ding, Naihuan Jing

Recently the second named author discovered a combinatorial identity in the context of vertex representations of quantum Kac-Moody algebras. We give a direct and elementary proof of this identity. Our method is to show a related identity of distributions.

Yu. A. Neretin

Consider an unitary highest weight representation of a group U(p,q) in holomorphic functions on the symmetric space U(p,q)/U(p)\times U(q). Consider its restriction ρto the subgroup O(p,q). This restriction has a complicated spectrum consisting of representations having different types. We construct a decomposition of ρto a finite direct sum of representatio

Allen Hatcher

This is a "software upgrade" to a paper originally published in 1976, with cleaner statements and improved proofs. The main result is that, in a Haken 3-manifold, the space of all incompressible surfaces in a single isotopy class is contractible, except when the surface is the fiber of a surface bundle structure, in which case the space of all surfac

C. Badea

We show that certain dense and spectral invariant subalgebras of a $C^*$-algebra have the same bilateral Bass stable rank. This is a partial answer for (a version of) an open problem raised by R.G. Swan. Then, for certain Banach algebras, we indicate when the homotopy groups $π_{i}(GL_{n}(A))$ stabilize for large $n$. This is an improvement of a result due t

C. Badea, M. Mbekhta

Suppose that $λ- T$ is left-invertible in $L(H)$ for all $λ\in Ω$, where $Ω$ is an open subset of the complex plane. Then an operator-valued function $L(λ)$ is a left resolvent of $T$ in $Ω$ if and only if $T$ has an extension $\tilde{T}$, the resolvent of which is a dilation of $L(λ)$ of a particular form. Generalized resolvents exist on every open set $U$,

Sergey Arkhipov

In this paper we construct some quantum analogues of the global Cousin complex for the flag variety in positive characteristic. Just like in the positive characteristic case, we obtain some remarkable resolutions of the contragradient modules over the small quantum group. We use these resolutions to calculate semiinfinite cohomology of the small quantum grou

Ruy Exel, Chi-Keung Ng

In this paper, we will define the reduced cross-sectional $C^*$-algebras of $C^*$-algebraic bundles over locally compact groups and show that if a $C^*$-algebraic bundle has the approximation property (defined similarly as in the discrete case), then the full cross-sectional $C^*$-algebra and the reduced one coincide. Moreover, if a semi-direct product bundl

Breno C. O. Imbiriba

The purpose of this work is to present some basic concepts about the non-linear sigma model in a simple and direct way. We start with showing the bosonic model and the Wess-Zumino-Witten term, making some comments about its topological nature, and its association with the torsion. It is also shown that to cancel the quantum conformal anomaly the model should

Francesco Antonuccio, Akikazu Hashimoto, Oleg Lunin, Stephen Pinsky

We consider the Maldacena conjecture applied to the near horizon geometry of a D1-brane in the supergravity approximation and consider the possibility of testing the conjecture against the boundary field theory calculation using DLCQ. We propose the two point function of the stress energy tensor as a convenient quantity that may be computed on both sides of

Shuhei Mano, Yuhsuke Yoshida

By using BPS closed string, the entropy is calculated of the extremal five dimensional black hole consisting of Dirichlet onebranes, Dirichlet fivebranes and Kaluza-Klein momentum in the flat background approximation. In our formulations we consider two kinds of BPS closed strings with or without a winding number. In the former case heavy excitation modes of

J. B. Kogut, M. A. Stephanov, D. Toublan

We study SU(2) color QCD with even number of quark flavors. First, using QCD inequalities we show that at finite baryon chemical potential mu, condensation must occur in the channel with scalar diquark quantum numbers. This breaks the U(1) symmetry generated by baryon charge (baryon superconductivity). Then we derive the effective Lagrangian describing low l

Ram Brustein, David H. Oaknin

If in addition to the standard model fields, a new pseudoscalar field that couples to hypercharge topological number density, the hypercharge axion, exists, it can be produced in colliders in association with photons or Z bosons, and detected by looking for its decay into photons or Z's. For a range of masses below a TeV and coupling above a fraction of

M. A. Diaz, J. Ferrandis, J. C. Romao, J. W. F. Valle

Minimal R-parity violating supergravity predicts a value for $alpha_s(M_Z)$ smaller than in the case with conserved R-parity, and therefore closer to the experimental world average. We show that the R-parity violating effect on the $alpha_s$ prediction comes from the larger two-loop b-quark Yukawa contribution to the renormalization group evolution of the ga

T. A. Kaeding, S. Nandi

The lighter neutral scalar Higgs mass is examined in gauge-mediated supersymmetry-breaking models in which the messenger sector responsible for SUSY breaking is allowed to involve more general sets of $SU(3) \otimes SU(2) \otimes U(1)$ multiplets than those contained in the SU(5) $5 + \bar{5}$ or $10 + \bar{10}$ multiplets. The largest mass for the lighter s

Stanley J. Brodsky, Johan Rathsman

Commensurate scale relations are perturbative QCD predictions which relate observable to observable at fixed relative scale, such as the "generalized Crewther relation", which connects the Bjorken and Gross-Llewellyn Smith deep inelastic scattering sum rules to measurements of the e+ e- annihilation cross section. We show how conformal symmetry provi

Gianluca Oderda, Nikolaos Kidonakis, George Sterman

We review some techniques of resummation applied to heavy quark production in hadronic scattering and electroproduction near partonic threshold, and discuss the reduction of factorization scale dependence in resummed cross sections.

Andreas Vogt

Results are presented of two studies addressing the scaling violations of deep-inelastic structure functions. Factorization-scheme independent fits to all ep and mu p data on F_2 are performed at next-to-leading order (NLO), yielding alpha_s(M_Z) = 0.114 +- 0.002_exp (+0.006-0.004)_th . In order to reduce the theoretical error dominated by the renormalizatio

Jan Kalinowski

In a general two-Higgs-doublet model with CP violation in the Higgs sector, the three neutral physical Higgs bosons have no definite CP properties. A new sum rule relating Yukawa and Higgs-Z couplings implies that a neutral Higgs boson cannot escape detection at an e^+e^- collider if it is kinematically accessible in Z+Higgs, $b\bar b+$Higgs and $t\bar t+$Hi

Utpal Sarkar

Majorana masses of the neutrino implies lepton number violation and is intimately related to the lepton asymmetry of the universe, which gets related to the baryon asymmetry of the universe in the presence of the sphalerons during the electroweak phase transition. Assuming that the baryon asymmetry of the universe is generated before the electroweak phase tr

V. A. Khoze, D. J. Miller, S. Moretti, W. J. Stirling

The production of four hadronic jets in e+e- collisions above the Z pole is dominated by the QCD e+e- --> qqqq,qqgg processes and, for sufficiently high energy, the electroweak e+e- --> W+W- --> qqqq process. However there is another mechanism for producing four jets, e+e- --> Z gg --> qqgg, which can be regarded as a `hadronic return' to the Z pole. We

F. M. Renard

Contribution to LP99, International Symposium on Lepton-Photon Interactions, Stanford, Aug.1999. Summary of works done in collaboration with M. Beccaria, P. Ciafaloni, D. Comelli, G.J. Gounaris, J. Layssac, P. Porfyriadis, S. Spagnolo, C. Verzegnassi. We report on several works dealing with precison tests of the Standard Model (SM) and beyond, in the process

Heather E. Logan

We explore the radiative corrections to the process Z --> b b-bar in models with extended Higgs sectors. The observables R_b (the Z hadronic branching fraction to b b-bar) and the b-quark asymmetry A_b = (g_L^2 - g_R^2)/(g_L^2 + g_R^2) are sensitive to these corrections. We find that in models containing only Higgs doublets, singlets, or larger multiplets co

Panagiota Kanti, Keith A. Olive

We address the problem of the large initial field values in chaotic inflation and propose a remedy in the framework of the so-called assisted inflation. We demonstrate that a 4-dimensional theory of multiple, scalar fields with initial field values considerably below the Planck scale, can give rise to inflation even though none of the individual scalar field

Simon Hands, Biagio Lucini

We present Monte Carlo simulation results for the three dimensional Thirring model on moderate sized lattices using a hybrid molecular dynamics algorithm which permits an odd or non-integer number Nf of fermion flavors. We find a continuous chiral symmetry breaking transition for Nf approximately equal to 3 with critical exponents consistent with expectation

LVD Collaboration

We present the analysis of the muon events with all muon multiplicities collected during 21804 hours of operation of the first LVD tower. The measured depth-angular distribution of muon intensities has been used to obtain the normalization factor, A, the power index, gamma, of the primary all-nucleon spectrum and the ratio, R_c, of prompt muon flux to that o

Ingemar Bengtsson, Soeren Holst

Morrow-Jones and Witt have shown that generic spatial topologies admit initial data that evolve to locally de Sitter spacetimes under Einstein's equations. We simplify their arguments, make them a little more general, and solve for the global time evolution of the wormhole initial data considered by them. Finally we give explicit examples of locally de S

Jan Sladkowski

We use various results concerning isometry groups of Riemannian and pseudo-Riemannian manifolds to prove that there are spaces on which differential structure can act as a source of gravitational force (Brans conjecture). The result is important for the analysis of the possible physical meaning of differential calculus. Possible astrophysical consequences ar

Alexander Yu. Grosberg

The size of a zero thickness (no excluded volume) polymer ring is shown to scale with chain length $N$ in the same way as the size of the excluded volume (self-avoiding) linear polymer, as $N^ν$, where $ν\approx 0.588$. The consequences of that fact are examined, including sizes of trivial and non-trivial knots.

William J. Mullin

We examine Bose-Einstein condensation (BEC) for particles trapped in a harmonic potential by considering it as a transition in the length of permutation cycles that arise from wave-function symmetry. This ``loop-gas'' approach was originally developed by Feynman in his path-integral study of BEC for an homogeneous gas in a box. For the harmonic oscil

Vladimir Privman

In this work we survey selected theoretical developments for models of deposition of extended particles, with and without surface diffusion, on linear and planar substrates, of interest in colloid, polymer, and certain biological systems.

Domingo Prato, Constantino Tsallis

We derive a useful expression for the matrix elements $[\frac{\partial f[A(t)]}{\partial t}]_{i j}$ of the derivative of a function $f[A(t)]$ of a diagonalizable linear operator $A(t)$ with respect to the parameter $t$. The function $f[A(t)]$ is supposed to be an operator acting on the same space as the operator $A(t)$. We use the basis which diagonalizes A(

J. A. Duffy, S. B. Dugdale, J. E. McCarthy, M. A. Alam

The first direct evidence of an induced spin moment in Gd(62.4)Y(37.6) is presented. This additional moment, of 0.16 +/- 0.03 Bohr magnetons, arises from polarisation of Y electrons in the alloy. The moment was detected in a Compton scattering experiment via the measurement of the one dimensional projection of the momentum space electron spin density in Gd a

R. Egger

The low-energy theory for multi-wall carbon nanotubes including the long-ranged Coulomb interactions, internal screening effects, and single-electron hopping between graphite shells is derived and analyzed by bosonization methods. Characteristic Luttinger liquid power laws are found for the tunneling density of states, with exponents approaching their Fermi

Mario Cuoco, Peter Horsch, Frank Mack

Using finite temperature diagonalization techniques it is shown that the quarter-filled t-J-V model on a trellis lattice structure provides a quantitative explanation of the highly anisotropic optical conductivity of the $α'-NaV_{2}O_{5}$ compound. The combined effects of the short-range Coulomb interaction and valence fluctuations of V-ions determine th

C. Bauer, S. Dietrich

Based on a microscopic density functional theory we investigate the morphology of thin liquidlike wetting films adsorbed on substrates endowed with well-defined chemical heterogeneities. As paradigmatic cases we focus on a single chemical step and on a single stripe. In view of applications in microfluidics the accuracy of guiding liquids by chemical microch

Jens Schneider, Axel Schenzle

Atom lasers based on rf-outcoupling can be described by a set of coupled generalized Gross-Pitaevskii equations (GPE). We compare the theoretical predictions obtained by numerically integrating the time-dependent GPE of an effective one-dimensional model with recently measured experimental data for the F=2 and F=1 states of Rb-87. We conclude that the output

Franco Bagnoli, Michele Bezzi

In this review some simple models of asexual populations evolving on smooth landscapes are studied. The basic model is based on a cellular automaton, which is analyzed here in the spatial mean-field limit. Firstly, the evolution on a fixed fitness landscape is considered. The correspondence between the time evolution of the population and equilibrium propert

Teresa Castan, Eduard Vives, Per-Anker Lindgaard

The degenerate Blume-Emery-Griffiths model for martensitic transformations is extended by including both structural and magnetic degrees of freedom in order to elucidate premartensitic effects. Special attention is paied to the effect of the magnetoelastic coupling in Ni2MnGa. The microscopic model is constructed and justified based on the analysis of the ex

Asish K. Dhara, S. R. Banerjee

We analyse the effect of synchronization between noise and periodic signal in a two-state spatially extended system analytically. Resonance features are demonstrated. To have the maximum cooperation between signal and noise, it is shown that noise strength at resonance should increase linearly with the frequency of the signal. The time scale of the process a

J. E. Hirsch

It is proposed that when a charge current circulates in a paramagnetic metal a transverse spin imbalance will be generated, giving rise to a 'spin Hall voltage'. Similarly, that when a spin current circulates a transverse charge imbalance will be generated, hence a Hall voltage, in the absence of charge current and magnetic field. Based on these prin

A. Damascelli, D. van der Marel, G. Dhalenne, A. Revcolevschi

We investigated in detail the optical properties of several Cu(1-delta)Mg(delta)GeO3 (with delta=0,0.01), and CuGe(1-x)B(x)O3 with B=Si (x=0,0.007,0.05,0.1), and Al (x=0,0.01) single crystals, in the frequency range 20-32000 cm^-1. We report temperature dependent reflectivity and transmission measurements, performed with polarized light in order to probe the

S. Curtarolo, G. Stan, M. J. Bojan, M. W. Cole

Grand canonical simulations are used to calculate adsorption isotherms of various classical gases on alkali metal and Mg surfaces. Ab initio adsorption potentials and Lennard-Jones gas-gas interactions are used. Depending on the system, the resulting behavior can be nonwetting for all temperatures studied, complete wetting, or (in the intermediate case) exhi

Kevin R. Vixie, Murray Wolinsky, David Sigeti

Controversy regarding the correctness of a test for aliasing proposed by Hinich and Wolinsky has been surprisingly long-lived. Two factors have prolonged this controversy. One factor is the presence of deep-seated intuitions that such a test is fundamentally incoherent. Perhaps the most compelling objection is that, given a set of discrete-time samples, one

Torsten A. Ensslin

We investigate the possibility that patches of old radio plasma (`radio ghosts') of former radio galaxies form a second distinct phase of the inter-galactic medium (IGM), not mixed with the thermal gas. The separation of this phase from the ambient gas and its resistance against eroding turbulent forces is given by magnetic fields, which are expected to

Jayadev Rajagopal, G. Srinivasan

We present a survey of molecular gas in the J = 1 -> 0 transition of 12CO towards the IRAS Vela shell. The shell, previously identified from IRAS maps, is a ring-like structure seen in the region of the Gum Nebula. We confirm the presence of molecular gas associated with some of the infrared point sources seen along the Shell. We have studied the morphology

Jaume Garriga, Mario Livio, Alexander Vilenkin

We explore a model in which the cosmological constant $Λ$ and the density contrast at the time of recombination $σ_{rec}$ are random variables, whose range and {\it a priori} probabilities are determined by the laws of physics. (Such models arise naturally in the framework of inflationary cosmology.) Based on the assumption that we are typical observers, we

M. Catanese, I. H. Bond, S. M. Bradbury, A. C. Breslin

Markarian 421 was observed for about four days with BeppoSAX and the Whipple Observatory gamma-ray telescope in April 1998. A pronounced, well-defined, flare with hour-scale variability was observed simultaneously in X-rays and very high energy gamma-rays. These data provide the first evidence that the X-ray and TeV intensities are well correlated on time-sc

J. Gorosabel, A. J. Castro-Tirado, A. Pedrosa, M. R. Zapatero-Osorio

We report optical observations of the GRB 980329 error box which represent the second earliest detection of the GRB 980329 optical transient. We determine R = 23.7 $\pm$ 0.5 mag on 29.89 March, which is consistent with R = 23.6 $\pm$ 0.2 mag as reported by Palazzi et al. (1998) on 29.99 March. Based on extrapolations of the light curve we claim that the R-ba

Prasad Subramanian, K. P. Dere, N. B. Rich, R. A. Howard

We have examined images from the Large Angle Spectroscopic Coronagraph (LASCO) to study the relationship of Coronal Mass Ejections (CMEs) to coronal streamers. We wish to test the suggestion (Low 1996) that CMEs arise from flux ropes embedded in a streamer erupting, thus disrupting the streamer. The data span a period of two years near sunspot minimum throug

F. R. Boffi, W. B. Sparks, F. D. Macchetto

Supernova (SN) light echoes could be a powerful tool for determining distances to galaxies geometrically, Sparks 1994. In this paper we present CCD photometry of the environments of 64 historical supernovae, the first results of a program designed to search for light echoes from these SNe. We commonly find patches of optical emission at, or close to, the sit

AMANDA collaboration

We review the status of the AMANDA neutrino telescope. We present results obtained from the four-string prototype array AMANDA-B4 and describe the methods of track reconstruction and neutrino event separation. We give also first results of the analysis of the 10-string detector AMANDA-B10, in particular on atmospheric neutrinos and the search for magnetic mo

W. J. Percival, L. Miller

We calculate the rate at which dark matter halos merge to form higher mass systems. Two complementary derivations using Press-Schechter theory are given, both of which result in the same equation for the formation rate. First, a derivation using the properties of the Brownian random walks within the framework of Press-Schechter theory is presented. We then u

E. Andres

AMANDA is a high-energy neutrino telescope presently under construction at the geographical South Pole. In the Antarctic summer 1995/96, an array of 80 optical modules (OMs) arranged on 4 strings (AMANDA-B4) was deployed at depths between 1.5 and 2 km. In this paper we describe the design and performance of the AMANDA-B4 prototype, based on data collected be

YBJ Collaboration, presented by S. Bussino

The structure of a neural network developed for the gamma hadron separation in the ARGO-YBJ detector is presented. The discrimination power in the full ARGO-YBJ energy range is shown in detail and the improvement in the detector sensitivity is also discussed.

M. J. Carson, B. McKernan, T. Yaqoob, D. J. Fegan

We analyse ASCA x-ray data and Whipple γ-ray data from the blazars Mkn421 and Mkn501 for short-timescale variability. We find no evidence for statistically significant (>3σ) variability in these data, in either source, on timescales of less than \sim 10 minutes.

Jose-Luis Gomez, Alan P. Marscher, Antonio Alberdi

We present the first 86 GHz VLBI observations of the radio galaxy 3C~120, together with contemporaneous 43 and 22 GHz polarimetric VLBA observations. The very high angular resolution obtained at 86 GHz provides an upper limit to the size of the core of 54 $μ$as (0.025 $h^{-1}$pc). This represents a direct determination of the base of the jet which is indepen

M. Revnivtsev, M. Gilfanov, E. Churazov

We studied the frequency resolved energy spectra of Cyg X--1 during the standard low (hard) spectral state using the data of the Rossi X-Ray Timing Explorer. We found that the relative amplitude of the reflection features -- the iron fluorescent line at ~6.5 keV and the smeared edge above ~7 keV -- decreases with the increasing frequency. In particular we fo

M. I. Wilkinson, N. W. Evans

A simple model for the Milky Way halo is presented. It has a flat rotation curve in the inner regions, but the density falls off sharply beyond an outer edge. This truncated, flat rotation curve (TF) model possesses a rich family of simple distribution functions which vary in velocity anisotropy. The model is used to estimate the total mass of the Milky Way

Ian Smail, Rob Ivison, Andrew Blain, Jean-Paul Kneib

We discuss deep surveys in the submm regime using the SCUBA bolometer array on the JCMT. At 850um SCUBA has resolved the bulk of the submm background (SMBR) detected by COBE into discrete sources brighter than 0.5mJy. The on-going identification and characterisation of this population at other wavelengths suggests that the bulk of the submm sources brighter

Kaspar von Braun, Kristin Chiboucas, Denise Hurley-Keller

We present a World-Wide-Web-accessible database of astronomical images which suffer from a variety of observational problems, ranging from common occurences, such as dust grains on filters and/or the dewar window, to more exotic phenomena, such as loss of primary mirror support due to the deflation of the support airbags. Apart from its educational usefulnes

R. Tagliaferri, A. Ciaramella, F. Barone, L. Milano

In this paper we present a neural network based estimator system which performs well the frequency extraction from unevenly sampled signals. It uses an unsupervised Hebbian nonlinear neural algorithm to extract the principal components which, in turn, are used by the MUSIC frequency estimator algorithm to extract the frequencies. We generalize this method to

Gustavo Burdman, M. C. Gonzalez-Garcia, S. F. Novaes

We study the potential effect of anomalous couplings of the third generation quarks to gauge bosons in rare B decays. We focus on the constraints from flavor changing neutral current processes such as $b\to sγ$ and $b\to s \ell^+\ell^-$. We consider both dimension-four and dimension-five operators and show that the latter can give large deviations from the s

Choongseop Lee, Boldizsar Janko, Imre Derenyi, Albert-Laszlo Barabasi

A serious obstacle that impedes the application of low and high temperature superconductor (SC) devices is the presence of trapped flux. Flux lines or vortices are induced by fields as small as the Earth's magnetic field. Once present, vortices dissipate energy and generate internal noise, limiting the operation of numerous superconducting devices. Metho

Hsin-Chia Cheng, Bogdan A. Dobrescu, Christopher T. Hill

We study gauge coupling unification in the presence of extra dimensions compactified at a few TeV. Achieving unification requires a large number of gauge boson Kaluza-Klein excitations lighter than the string scale, such that the higher-dimensional gauge couplings are O(1) in string scale units. Corrections to the gauge couplings from two or more loops are a

P. Matlock, K. S. Viswanathan

The complete solution to the massive Rarita-Schwinger field equation in anti-de Sitter space is constructed, and used in the AdS/CFT correspondence to calculate the correlators for the boundary conformal field theory. It is found that when no condition is imposed on the field solution, there appear two different boundary conformal field operators, one coupli

Asher Peres

If several interventions performed on a quantum system are localized in mutually space-like regions, they will be recorded as a sequence of ``quantum jumps'' in one Lorentz frame, and as a different sequence of jumps in another Lorentz frame. Conditions are specified that must be obeyed by the various operators involved in the calculations so that th

W. T. Lu, F. Y. Wu

Closed-form expressions are obtained for the generating function of close-packed dimers on a $2M \times 2N$ simple quartic lattice embedded on a Möbius strip and a Klein bottle. Finite-size corrections are also analyzed and compared with those under cylindrical and free boundary conditions. Particularly, it is found that, for large lattices of the same size

H. Umeda, K. Nomoto, C. Kobayashi, I. Hachisu

Observations suggest that the properties of Type Ia supernovae (SNe Ia) may depend on environmental characteristics, such as morphology, metallicity, and age of host galaxies. The influence of these environmental properties on the resulting SNe Ia is studied in this paper. First it is shown that the carbon mass fraction X(C) in the C+O white dwarf SN Ia prog

M. A. Barstow, I. Hubeny, J. B. Holberg

The presence of heavy elements in the atmospheres of the hottest H-rich DA white dwarfs has been the subject of considerable interest. While theoretical calculations can demonstrate that radiative forces, counteracting the effects of gravitational settling, can explain the detections of individual species, the predicted abundances do not accord well with obs

Adi Armoni, Barak Kol

We use dyonic brane configurations of type 0 string theory to study large N non-supersymmetric 4d gauge theories. The brane configurations define theories similar to the supersymmetric ones which arise in type II. We find the non-SUSY analogues of N=2 and N=1. In particular we suggest new non-SUSY CFT's and a brane realization of a non-SUSY Seiberg duali

J. Bobroff, W. A. MacFarlane, H. Alloul, P. Mendels

We compare the effects of in-plane non magnetic Li$^{+}$ and Zn$^{2+}$ impurities on the normal state of high-T$_{c}$ cuprates. Y NMR shows that the extra hole introduced by Li is not localized in its vicinity. The Tc depression and induced moments on near neighbour Cu sites of Zn or Li are found identical. These universal effects of spinless impurities esta

Kazusumi Ino

We show that the so-called permanent quantum Hall states are formed by the integer quantum Hall effects on the Haldane-Rezayi quantum Hall state. Novel conformal field theory description along with this picture is deduced. The odd denominator plateaux observed around $ν=5/2$ are the permanent states if the $ν=5/2$ plateau is the Haldane-Rezayi state. We poin

M. Beccaria, P. Ciafaloni, D. Comelli, F. M. Renard

Starting from a theoretical representation of the electroweak component of four-fermion neutral current processes that uses as theoretical input the experimental measurements at the Z peak, we consider the asymptotic high energy behaviour in the Standard Model at one loop of those gauge-invariant combinations of self-energies, vertices and boxes that contrib

R. Foot

We re-examine the evolution of neutrino asymmetries in several four neutrino models. The first case involves the direct creation of $L_{ν_e}$ by $ν_e \leftrightarrow ν_s$ oscillations. In the second case, we consider the mass hierarchy $m_{ν_τ} \gg m_{ν_μ}, m_{ν_e}, m_{ν_s}$ where $ν_τ\leftrightarrow ν_s$ oscillations generate a large $L_{ν_τ}$ and some of t

Y. L. Wu, Y. F. Zhou

A phenomenological analysis of the general two Higgs doublet model is presented. Possible constraints of the Yukawa couplings are obtained from the $K^0-\bar{K}^0, B^0-\bar{B}^0$ and $D^0-\bar{D}^0$ mixings. A much larger $D^0-\bar{D}^0$ mixing than the standard model prediction is possible. It is shown that the emerging of various new sources of CP violatio

R. N. Faustov, A. P. Martynenko

The contribution of hadronic vacuum polarization to the Lamb shift in muonic hydrogen is evaluated with the account of modern experimental data on the cross section of $e^+e^-$ annihilation into hadrons. The numerical value of this contribution to the (2P-2S) shift in muonic hydrogen is equal to 10.77 $μeV$.

N. N. Achasov, V. V. Gubin

We comment on the paper by Benayoun, DelBuono, Eidelman, Ivanchenko, and O'Connell [Phys. Rev. {\bf D 59}, 114027 (1999)]. We show that the decay $ϕ\toπ^0γ$ is absent in model of the nonet symmetry and SU(3) breaking suggested by authors.

Y. Castin, R. Dum

We investigate minimal energy solutions with vortices for an interacting Bose-Einstein condensate in a rotating trap. The atoms are strongly confined along the axis of rotation z, leading to an effective 2D situation in the x-y plane. We first use a simple numerical algorithm converging to local minima of energy. Inspired by the numerical results we present

Jin-Ho Cho, Taejin Lee, Gordon Semenoff

We realize the two dimensional anti-de Sitter ($AdS_2$) space as a Kaluza-Klein reduction of the $AdS_3$ space in the framework of the discrete light cone quantization (DLCQ). Introducing DLCQ coordinates which interpolate the original (unboosted) coordinates and the light cone coordinates, we discuss that $AdS_2/CFT$ correspondence can be deduced from the $

P. M. Singer, A. W. Hunt, A. F. Cederstrom, T. Imai

We demonstrate that the integrated intensity of Cu-63 nuclear quadrupole resonance (NQR) in La(1.6-x)Nd(0.4)Sr(x)CuO(4) decreases dramatically below the charge-stripe ordering temperature T(charge). Comparison with neutron and X-ray scattering indicates that the wipeout fraction F(T) (i.e. the missing fraction of the integrated intensity of the NQR signal) r

Eric W. Deutsch

In order to understand the positional uncertainties of arbitrary objects in several of the current major databases containing astrometric information, a sample of extragalactic radio sources with precise positions in the International Celestial Reference Frame (ICRF) is compared with the available positions of their optical counterparts. The discrepancies be

F. W. Nijhoff, N. Joshi, A. Hone

A Miura chain is a (closed) sequence of differential (or difference) equations that are related by Miura or Bäcklund transformations. We describe such a chain for the sixth Painlevé equation (\pvi), containing, apart from \pvi itself, a Schwarzian version as well as a second-order second-degree ordinary differential equation (ODE). As a byproduct we derive a

Yunbo Zeng, Wen-Xiu Ma

It is shown how to construct an infinite number of families of quasi-bi-Hamiltonian (QBH) systems by means of the constrained flows of soliton equations. Three explicit QBH structures are presented for the first three families of the constrained flows. The Nijenhuis coordinates defined by the Nijenhuis tensor for the corresponding families of QBH systems are

G. L. Klimchitskaya, Anushree Roy, U. Mohideen, V. M. Mostepanenko

We consider detailed roughness and conductivity corrections to the Casimir force in the recent Casimir force measurement employing an Atomic Force Microscope. The roughness of the test bodies-a metal plate and a sphere- was investigated with the Atomic Force Microscope and the Scanning Electron Microscope respectively. It consists of separate crystals of dif

Constantine Yannouleas, Uzi Landman

The Ionization Potentials of small Li_N clusters are calculated with a Shell Correction Method. They are used to illustrate that, within the jellium approximation, deformed cluster shapes provide an adequate description of the observed systematic size dependence of the properties of simple metal clusters. Such deformation effects were overlooked in the analy

A. K. Motovilov, E. A. Kolganova

Algorithm, based on explicit representations for the analytic continuation of Faddeev components of the three-body T-matrix in unphysical energy sheets, is employed to study mechanism of disappearance and formation of the Efimov levels of the helium ^4He trimer.

Sergio Szpigel, Robert Perry

We use two renormalization techniques, Effective Field Theory and the Similarity Renormalization Group, to solve simple Schr{ö}dinger equations with delta-function potentials in one and two dimensions. The familiar one-dimensional delta-function does not require renormalization, but it provides the simplest example of a local interaction that can be replaced

A. V. Kopylov

The comparison of magnetic moments of neutron and proton reveals three possible states of a nucleon. The arguments are presented why these states can be the stationary states.

Hiroto Kobayashi

It is pointed out that Reinsch's matrix operation formulation of calculating the Baker-Campbell-Hausdorff series [math-ph/9905012] is equivalent to the straightforward series expansion. The amount of calculation does not decrease by his method.

A. K. Motovilov, R. Mennicken

We consider the analytic continuation of the transfer function for a 2x2 matrix Hamiltonian into the unphysical sheets of the energy Riemann surface. We construct non-selfadjoint operators representing operator roots of the transfer function which reproduce certain parts of its spectrum including resonances situated in the unphysical sheets neighboring the p

Matt DeLong

A formula is given for the dimension of the Selmer group of the rational three-isogeny of elliptic curves of the form y^2=x^3+a(x-b)^2. The formula is in terms of the three-ranks of the quadratic number fields Q(\sqrt{a}) and Q(\sqrt{-3a}) and various aspects of the arithmetic of these number fields. In addition a duality theorem is used to relate the dimens

Allen Hatcher

This brief report (6 pages) was written in 1983 but never published. It concerns the hyperbolic 3-orbifolds obtained as quotients of hyperbolic 3-space by the group of invertible 2 by 2 matrices whose entries are integers in the imaginary quadratic extension of Q of discriminant D. For values D > -100 the topological type of this orbifold is tabulated, and i

A. Dimca, L. Paunescu

We obtain sharp estimates on the connectivity of complex affine hypersurfaces in terms of the decomposition of the defining equation as a sum of weighted homogeneous components relative to some weight system.

M. Deza, M. I. Shtogrin

We review the regular tilings of d-sphere, Euclidean d-space, hyperbolic d-space and Coxeter's regular hyperbolic honeycombs (with infinite or star-shaped cells or vertex figures) with respect of possible embedding, isometric up to a scale, of their skeletons into a m-cube or m-dimensional cubic lattice. In section 2 the last remaining 2-dimensional case