January 2000 arXiv papers — page 14

Chongxing Yue, Yu-Ping Kuang, Xue-Lei Wang, Weibin Li

Recent study on the charged top-pion correction to R_b shows that it is negative and large, so that the precision experimental value of R_b gives rise to a severe constraint on the topcolor-assisted technicolor models such that the top-pion mass should be of the order of 1 TeV. In this paper, we restudy this constraint by further taking account the extended

S. Fajfer, P. Singer

The decay $B^- \to K^- K^- π^+$ has been sugested as a test for minimal supersymmetric standard model and for supersymmetric models with R-parity violating couplings, in view of its extreme smallnesss in the standard model. We calculate two long distance contributions to this decay, that associated with $DD$ and $Dπ$ intermediate states and that induced by v

V. A. Sadovnikova

In symmetrical nuclear matter the solutions of pion dispersion equation are investigated in the complex plane of the pion frequency ω. There are three well-known branches of solutions on the physical sheet : sound, pion and isobar, at the matter density less than the critical one ρ<ρ_c. At ρ>ρ_c the fourth branch appears on the physical sheet. For this branc

V. Skalsky

The present temperature of cosmic background radiation and the present number density of photons of cosmic background radiation in the observed expansive and isotropic relativistic Universe is in the standard model of universe explained by the assumption of emergence of the photons of cosmic background radiation on the horizon (of the most remote visibility)

M. C. Gonzalez-Garcia, C. Peña-Garay

We review the status of neutrino masses and mixings in the light of the solar and atmospheric neutrino data. The result from the LSND experiment is also considered. We discuss the present knowledge and the expected sensitivity to the neutrino mixing parameters in the simplest schemes proposed to reconcile these data some of which include a light sterile neut

Giampiero Esposito

The fundamental laws of physics can be derived from the requirement of invariance under suitable classes of transformations on the one hand, and from the need for a well-posed mathematical theory on the other hand. As a part of this programme, the present paper shows under which conditions the introduction of pseudo-differential boundary operators in one-loo

N. V. Ustinov

A new approach for obtaining the transformations of solutions of nonlinear ordinary differential equations representable as the compatibility condition of the overdetermined linear systems is proposed. The corresponding transformations of the solutions of the overdetermined linear systems are derived in the frameworks of the Darboux transformation technique.

T. MacKenzie, A. J. Roberts

We analyse the nonlinear Kuramoto-Sivashinsky equation to develop an accurate finite difference approximation to its dynamics. The analysis is based upon centre manifold theory so we are assured that the finite difference model accurately models the dynamics and may be constructed systematically. The theory is applied after dividing the physical domain into

Martin White, Rupert A. C. Croft

Recently is has been suggested that the dearth of small halos around the Milky Way arises due to a modification of the primordial power spectrum of fluctuations from inflation. Such modifications would be expected to alter the formation of structure from bottom-up to top-down on scales near where the short-scale power has been suppressed. Using cosmological

A. De Rujula, M. B. Gavela, P. Hernandez

We consider a pattern of neutrino masses in which there is an approximate mass degeneracy between the two mass eigenstates most coupled to the $ν_μ$ and $ν_τ$ flavour eigenstates. Earth-matter effects can lift this degeneracy and induce an effectively maximal mixing between these two generations. This occurs if $ν_e$&#39;s contain comparable admixtures of th

H. De Raedt, A. H. Hams, K. Michielsen, S. Miyashita

We describe a simulation method for a quantum spin model of a generic, general purpose quantum computer. The use of this quantum computer simulator is illustrated through several implementations of Grover&#39;s database search algorithm. Some preliminary results on the stability of quantum algorithms are presented.

Sixia Yu

The concept of the {\em half density matrix} is proposed. It unifies the quantum states which are described by density matrices and physical processes which are described by completely positive maps. With the help of the half-density-matrix representation of Hermitian linear map, we show that every positive map which is not completely positive is a {\em diff

Sixia Yu, Chang-Pu Sun

Canonically conjugated observables such as position-momentum and phase-number are found to play a 3-fold role in the drama of the quantum teleportation. Firstly, the common eigenstate of two commuting canonical observables like phase-difference and number-sum provides the quantum channel between two systems. Secondly, a similar pair of canonical observables

Ping Zhu, Gao Shan

This paper was removed by arXiv admin due to metadata abuse.

Shi-Na Tan

A powerful approach to solve the Coulombic quantum three-body problem is proposed. The approach is exponentially convergent and more efficient than the Hyperspherical Coordinate(HC) method and the Correlation Function Hyperspherical Harmonic(CFHH) method. This approach is numerically competitive with the variational methods, such as that using the Hylleraas-

A. I. Titov, B. Kämpfer, B. L. Reznik

We analyze the production of $ϕ$ mesons in $πN$ and NN reactions in the near-threshold region, using throughout the conventional ``non-strange&#39;&#39; dynamics based on such processes which are allowed by the non-ideal $ω-ϕ$ mixing. We show that the occurrence of the direct $ϕNN$ interaction may show up in different unpolarized and polarization observables

L. P. Kaptari, B. Kämpfer, E. Grosse

A covariant model based on the Bethe-Salpeter formalism is proposed for investigating the solar proton burning process $pp\to De^+ν_e$ and the near-threshold deuteron disintegration via electromagnetic and weak interactions. Results of numerical calculations of the energy dependence of relevant cross sections and the astrophysical low-energy cross section fa

W. Cassing, E. L. Bratkovskaya, S. Juchem

We calculate excitation functions for various dynamical quantities as well as experimental observables from SIS to RHIC energies within the HSD transport approach which is based on string, quark, diquark ($q, \bar{q}, qq, \bar{q}\bar{q}$) and hadronic degrees of freedom without including any explicit phase transition to a quark-gluon plasma (QGP). It is argu

T. Vertse, A. T. Kruppa, W. Nazarewicz

Shell corrections of the finite deformed Woods-Saxon potential are calculated using the Green&#39;s function method and the generalized Strutinsky smoothing procedure. They are compared with the results of the standard prescription which are affected by the spurious contribution from the unphysical particle gas. In the new method, the shell correction approa

S. Rajesh, G. Ananthakrishna

The dynamics of a model, originally proposed for a type of instability in plastic flow, has been investigated in detail. The bifurcation portrait of the system in two physically relevant parameters exhibits a rich variety of dynamical behaviour, including period bubbling and period adding or Farey sequences. The complex bifurcation sequences, characterized b

Miloslav Znojil

Wave functions and energies are constructed in a short-range Poeschl-Teller well (= negative quadratic secans hyperbolicus) with a quartic perturbation. Within the framework of an innovated, Lanczos-inspired perturbation theory we show that our choice of non-orthogonal basis makes all the corrections given by closed formulae. The first few items are then gen

Michael Baake, Robert V. Moody, Peter A. B. Pleasants

We prove that the set of visible points of any lattice of dimension at least 2 has pure point diffraction spectrum, and we determine the diffraction spectrum explicitly. This settles previous speculation on the exact nature of the diffraction in this situation, see math-ph/9903046 and references therein. Using similar methods we show the same result for the

Mark Gross, Sorin Popescu

We describe birational models and decide the rationality/unirationality of moduli spaces AA_{d} (and AA^{lev}_{d}) of (1,d)-polarized abelian surfaces (with canonical level structure, respectively) for small values of d. The projective lines identified in the rational/unirational moduli spaces correspond to pencils of abelian surfaces traced on nodal threefo

Alexander Brudnyi

Let M be a projective manifold, p:M_{G} --> M a regular covering over M with a free abelian transformation group G. We describe holomorphic functions on M_{G} of an exponential growth with respect to the distance defined by a metric pulled back from M. As a corollary we obtain for such functions Cartwright and Liouville type theorems. Our approach brings tog

Jie Wu

By studying braid group actions on Milnor&#39;s construction of the 1-sphere, we show that the general higher homotopy group of the 3-sphere is the fixed set of the pure braid group action on certain combinatorially described group. We also give certain representation of higher differentials in the Adams spectral sequence for the homotopy groups of the 2-sph

A. Brudnyi, A. Onishchik

We study the de Rham 1-cohomology H^1_{DR}(M,G) of a smooth manifold M with values in a Lie group G. By definition, this is the quotient of the set of flat connections in the trivial principle bundle $M\times G$ by the so-called gauge equivalence. We consider the case when M is a compact Kähler manifold and G is a solvable complex linear algebraic group of a

Mercedes H. Rosas

The Kronecker product of two Schur functions $s_μ$ and $s_ν$, denoted by $s_μ*s_ν$, is the Frobenius characteristic of the tensor product of the irreducible representations of the symmetric group corresponding to the partitions $μ$ and $ν$. The coefficient of $s_λ$ in this product is denoted by $γ^λ_{μν}$, and corresponds to the multiplicity of the irreducib

Alain Lascoux, Michel Lassalle

We prove an identity about partitions, previously conjectured in the study of shifted Jack polynomials (math.CO/9903020). The proof given is using $λ$-ring techniques. It would be interesting to obtain a bijective proof.

Alexander Golubev

We generalize the notion of trace to the Kontsevich quantization algebra and show that for all Poisson manifolds representable by quotients of a symplectic manifold by a Hamiltonian action of a nilpotent Lie group, the trace is given by integration with respect to a unimodular volume form.

R. R. Zapatrin

A duality between general partially ordered sets and certain topolgical spaces with two closures is established.

R. Banerjee

Using the commutativity of a general variation with the time differentiation we discuss both global and local (gauge) symmetries of a lagrangian from a unified point of view. The Noether considerations are thereby applicable for both cases. A complete equivalence between the hamiltonian and lagrangian formulations is established.

Thomas G. Rizzo

After an extremely brief overview of the discovery reach for Z&#39; bosons, we will discuss the physics of Kaluza-Klein(KK) excitations of the Standard Model gauge bosons that can be explored by a high energy muon collider in the era after the LHC and TeV Linear Collider. We demonstrate that the muon collider is a necessary ingredient in the unraveling the p

Lynne H. Orr, W. J. Stirling

The production of jet pairs at large rapidity difference at hadron colliders is potentially sensitive to BFKL physics. We present the results of a BFKL Monte Carlo calculation of dijets at the Tevatron. The Monte Carlo incorporates kinematic effects that are absent in analytic BFKL calculations; these effects significantly modify the behavior of dijet cross

Cosmin Macesanu, Lynne H. Orr

We present the results of an exact calculation of gluon radiation in top production and decay at high energy electron-positron colliders. We include all spin correlations and interferences, the bottom quark mass, and finite top width effects in the matrix element calculation. We study properties of the radiated gluons and implications for top mass measuremen

Lynne H. Orr, W. J. Stirling

Virtual photon scattering in e^+e^- collisions can result in events with the electron-positron pair at large rapidity separation with hadronic activity in between. The BFKL equation resums large logarithms that dominate the cross section for this process. We report here on a Monte Carlo method for solving the BFKL equation that allows kinematic constraints t

J. L. Lucio, M. Napsuciale

We show that therecently observed pion invariant mass distribution of the phi ->pi0 pi0 gamma decay can be satisfactorily described by the chiral U(3) X U(3) Linear Sigma Model.

M. Beneke

Talk given at XIXth International Symposium on Lepton and Photon Interactions at High Energies (LP 99), Stanford, California, 9-14 August 1999.

C. M. Carloni Calame, C. Lunardini, G. Montagna, O. Nicrosini

The accurate knowledge of luminosity at e^+ e^- flavour factories requires the precision calculation of the Bhabha cross section at large scattering angles. In order to achieve a theoretical accuracy at the 0.1% level, the relevant effect of QED radiative corrections is taken into account in the framework of the Parton Shower method, which allows exclusive e

V. M. Braun, G. P. Korchemsky, A. N. Manashov

We formulate a consistent 1/N_c^2 expansion of the QCD evolution equations for the twist-three quark distributions g_2(x,Q^2), h_L(x,Q^2) and e(x,Q^2) based on the interpretation of the evolution as a three-particle quantum-mechanical problem with hermitian Hamiltonian. Each distribution amplitude can be decomposed in contributions of partonic components wit

Athar Husain

I discuss the possibility of production of high energy cosmic neutrinos (E \geq 10^{6} GeV) in cores of active galactic nuclei and study some of the effects of neutrino mixing on their subsequent propagation. I also discuss the prospects for observations of these high energy cosmic neutrinos in new km^{2} surface area underwater/ice neutrino telescopes.

E. L. Berger, M. Klasen

The hadroproduction of lepton pairs with mass Q and finite transverse momentum Q_T is described in perturbative QCD by the same partonic subprocesses as prompt photon production. We demonstrate that, like prompt photon production, lepton pair production is dominated by quark-gluon scattering in the region Q_T>Q/2. This feature leads to sensitivity to the glu

Toby Falk

I discuss recent developments in the study of cosmological limits on the Minimal Supersymmetric Standard Model (MSSM). In particular, I focus on the effect of neutralino-stau coannihilation on the relic abundance of neutralinos, and I give examples where the cosmologically derived limits on the supersymmetric parameters are relaxed, and one example (CP viola

E852 Collaboration, J. Gunter, A. Dzierba

A partial wave analysis of the of the $π^0π^0$ system produced in the charge exchange reaction: $π^-p\to π^0π^0n$ at an incident momentum of $18.3 GeV/c$ is presented as a function of ${π^0π^0}$ invariant mass, $m_{π^0π^0}$, and momentum transfer squared, $| {t} |$, from the incident $π^-$ to the outgoing ${π^0π^0}$ system.

E. Kneringer

Data collected with the ALEPH detector at centre-of-mass energies between 130 and 189 GeV are used to search for Higgs bosons of the standard model and its supersymmetric extensions. No evidence for a Higgs particle has been found in 256 pb^-1 of LEP2 data. Mass exclusion limits were set.

Tonatiuh Matos, Dario Nuñez, Gabino Estevez, Maribel Rios

Using invariant transformations of the five-dimensional Kaluza-Klein (KK) field equations, we find a series of formulae to derive axial symmetric stationary exact solutions of the KK theory starting from static ones. The procedure presented in this work allows to derive new exact solutions up to very simple integrations. Among other results, we find exact ro

D. Grumiller, W. Kummer, D. V. Vassilevich

As shown recently (W. Kummer, H. Liebl, D.V. Vassilevich, Nucl. Phys. B 544, 403 (1999)) 2d quantum gravity theories --- including spherically reduced Einstein-gravity --- after an exact path integral of its geometric part can be treated perturbatively in the loops of (scalar) matter. Obviously the classical mechanism of black hole formation should be contai

Lorrie Faith Cranor

A variety of tools have been introduced recently that are designed to help people protect their privacy on the Internet. These tools perform many different functions in-cluding encrypting and/or anonymizing communications, preventing the use of persistent identifiers such as cookies, automatically fetching and analyzing web site privacy policies, and display

D. Molla, J. Berri, M. Hess

In this paper we describe ExtrAns, an answer extraction system. Answer extraction (AE) aims at retrieving those exact passages of a document that directly answer a given user question. AE is more ambitious than information retrieval and information extraction in that the retrieval results are phrases, not entire documents, and in that the queries may be arbi

Yu. D. Panov, A. S. Moskvin

Direct analytical and numerical calculation show that two-electron atomic configuration can be unstable with respect to a static or dynamic shift of the electron shells. This enables to develop a so called non-rigid shell model for a partial account of the electron correlations within atomic clusters in solids. In a framework of this model a correlated state

A. M. R. Teixeira, P. T. C. Freire, A. J. D. Moreno, J. M. Sasaki

Pressure-dependent Raman scattering studies in the range 0.0 -- 32 kbar were carried out in L-alanine in order to investigate its external mode phonon spectra in relation to the phase transitions in the crystal. A careful analysis of the spectra shows that the low-energy Raman modes exhibit variation both in frequency and in intensity and between 26 and 28 k

Fabrizio Lillo, Rosario N. Mantegna

We introduce a Langevin equation characterized by a time dependent drift. By assuming a temporal power-law dependence of the drift we show that a great variety of behavior is observed in the dynamics of the variance of the process. In particular diffusive, subdiffusive, superdiffusive and stretched exponentially diffusive processes are described by this mode

R. Haberkern, R. Rosenbaum, H. Bekar, M. Pilosof

The magnetoconductivity of quasicrystals is often discussed in the frame of quantum corrections, namely weak (anti-) localiza-tion and electron-electron interaction. A premise for both effects is a strong elastic scattering of conduction electrons. Amorphous and icosahedral phases are discussed as Hume-Rothery alloys with an electronically induced structural

H. Rosner, M. Divis, K. Koepernik, S. -L. Drechsler

Recent electronic structure calculations for the prototypical lowdimensional cuprate compounds CaCuO2 ans SrCuO2 performed by Wu et. al. (J. Phys.: Condens. Matter v. 11 p.4637 (1999))are critically reconsidered, applying high precision full-potential bandstructure methods. It is shown that the bandstructure calculations presented by the authors contain seve

H. Feldmeier, J. Schnack

The time-dependent variational principle for many-body trial states is used to discuss the relation between the approaches of different molecular dynamics models to describe indistinguishable fermions. Early attempts to include effects of the Pauli principle by means of nonlocal potentials as well as more recent models which work with antisymmetrized many-bo

S. V. Lotkhov, S. A. Bogoslovsky, A. B. Zorin, J. Niemeyer

We fabricated and tested the single electron R-pump, i.e. a three-junction Al circuit with on-chip Cr resistors. We show that due to the presence of the resistors (R > h/e^2 = 25.8 kOhm), the accuracy of electron transfer in the R-pump can approach the level of 10^-8. Preliminary results of experiment with the R-pump made at PTB are reported.

C. Attanasio, T. Di Luccio, L. V. Mercaldo, S. L. Prischepa

The transport properties of Nb/CuMn multilayers with a regular array of electron beam lithography obtained antidots have been measured at different temperatures in the presence of external perpendicular magnetic fields. Hysteretical I-V characteristics have been observed which disappear when approaching the upper critical magnetic field curve H_{c2}(T). Comp

D. Passerone, F. Ercolessi, E. Tosatti

Deposition/removal of metal atoms on the hex reconstructed (100) surface of Au, Pt and Ir should present intriguing aspects, since a new island implies hex -> square deconstruction of the substrate, and a new crater the square -> hex reconstruction of the uncovered layer. To obtain a microscopic understanding of how islands/craters form in these conditions,

Fan Zhong, Z. D. Wang

We analyze the symmetry of all possible magnetic structures of bilayered manganites La_{2-2x}Sr_{1+2x}Mn_2O_7 with doping 0.3 <= x < 0.5 and formulate a corresponding Landau theory of the phase transitions involved. It is shown that canting of spins is not allowed at x=0.3 though is at x=0.4. The observed magnetic reflections from the sample with x=0.3 may b

Oleg Tchernyshyov, Leonid P. Pryadko

We attempt to access the regime of strong coupling between charge carriers and transverse dynamics of an isolated conducting ``stripe&#39;&#39;, such as those found in cuprate superconductors. A stripe is modeled as a partially doped domain wall in an antiferromagnet (AF), introduced in the context of two different models: the t-J model with strong Ising ani

M. Markevitch, T. J. Ponman, P. E. J. Nulsen, M. W. Bautz

We use Chandra data to map the gas temperature in the central region of the merging cluster A2142. The cluster is markedly nonisothermal; it appears that the central cooling flow has been disturbed but not destroyed by a merger. The X-ray image exhibits two sharp, bow-shaped, shock-like surface brightness edges or gas density discontinuities. However, temper

R. J. Thacker, H. M. P. Couchman

We present results from a Smoothed Particle Hydrodynamic (SPH) simulation of galaxy formation that exceeds the minimum resolution requirement suggested by Steinmetz & Muller (1993) of 3*10^4 SPH particles per galaxy. Using the multiple mass technique an effective resolution of a little over one billion particles is attained within a 48 Mpc cube. We find that

James G. Bartlett

Thanks to advances in detector technology and observing techniques, true Sunyaev-Zel&#39;dovich (SZ) surveys will soon become a reality. This opens up a new window into the Universe, in many ways analogous to the X-ray band and inherently well-adapted to reaching high redshifts. I discuss the nature, abundance and redshift distributions of objects detectable

Ivo Saviane, Alfred Rosenberg, Giampaolo Piotto, Antonio Aparicio

The purpose of this study is to carry out a thorough investigation of the changes in morphology of the red giant branch (RGB) of Galactic globular clusters (GGC) as a function of metallicity, in the V,I bands. To this aim, two key points are developed in the course of the analysis. (a) Using our photometric V,I database for Galactic globular clusters (the la

D. Proust, H. Cuevas, H. V. Capelato, L. Sodre

We present the results of a dynamical analysis of three rich, X-ray luminous galaxy clusters, Abell 222, Abell 223 and Abell 520, that are at intermediate redshifts. Our study is based on radial velocities for 71 cluster members, respectively 30 for A222, 20 for A223 and 21 for A520, measured from spectra obtained at the Canada-France-Hawaii Telescope, the E

Stefanie Komossa

We first provide a review of the properties of warm absorbers concentrating on what we have learned from ROSAT and ASCA. This includes dusty and dust-free warm absorbers, non-X-ray emission and absorption features of warm absorbers, and the possible warm absorber interpretation of the peculiar 1.1 keV features. We then discuss facets of warm absorbers by a m

Gunnar Paesold, Arnold O. Benz

An electron distribution with a temperature anisotropy T_par/T_perp > 1 can lead to the Electron Firehose instability (Here par and perp denote directions relative to the background magnetic field B_0). Since possible particle acceleration mechanisms in solar flares exhibit a preference of energizing particles in parallel direction, such an anisotropy is exp

David B. Cline

We describe the current situation concerning methods to search for relic neutrinos from the Big Bang and from all past supernovae (SNs). The most promising method for Big Bang neutrinos is by the interaction of ultra-high- energy (UHE) neutrinos. For supernova neutrinos, both Super Kamiokande- and ICARUS-type detectors will be important to study both nubar_{

Michael J. Pierce, Robert C. Berrington

We present evidence for non-Gaussian velocity fields within the cores of luminous elliptical galaxies. This evidence is based upon high signal-to-noise, medium-resolution spectroscopy of the cores of early-type members of the Virgo and Coma clusters obtained with the WIYN 3.5-m telescope. The Virgo data were acquired using an integral-field unit (DensePak) a

S. Giordano, E. Antonucci, G. Noci, M. Romoli

The present spectroscopic study of the ultraviolet coronal emission in a polar hole, detected on April 6-9, 1996 with the Ultraviolet Coronagraph Spectrometer aboard the SOHO spacecraft, identifies the inter-plume lanes and background coronal hole regions as the channels where the fast solar wind is preferentially accelerated. In inter-plume lanes, at helioc

T. Venturi, S. Bardelli, R. Morganti, R. W. Hunstead

We present the results of a 22 cm radio survey carried out with the A3558 complex, a chain formed by the merging ACO clusters A3556-A3558-A3562 and thetwo groups SC1327-312 and SC1323-313, located in the central region of the complex, a chain formed by the merging ACO clusters A3556-A3558-A3562 and the two groups SC1327-312 and SC1323-313, located in the cen

D. Cormier, R. Holman

We study the out of equilibrium dynamics of inflationary phase transitions and compute the resulting spectrum of metric perturbations relevant to observation. We show that simple single field models of inflation may produce an adiabatic perturbation spectrum with a blue spectral tilt and that the precise spectrum depends on initial conditions at the outset o

Paola Andreani, Andrea Cimatti, Laurent Loinard, Huub Roettgering

CO J = 5 - 4 and J = 2 - 1 emission lines were detected towards the extremely red galaxy (ERG) HR10 (J164502+4626.4) at z=1.44. The CO intensities imply a molecular gas mass M(H2) of 1.6 x 10^{11} h^{-2}_50 solar masses, and, combined with the intensity of the dust continuum, a gas-to-dust mass ratio around 200-400 (assuming galactic values for the conversio

Donatella Romano, Francesca Matteucci

We adopt up-to-date yields of 7Li, 13C, 15N from classical novae and use a well tested model for the chemical evolution of the Milky Way in order to predict the temporal evolution of these elemental species in the solar neighborhood. In spite of major uncertainties due to our lack of knowledge of metallicity effects on the final products of explosive nucleos

V. Anguelov, S. Petrov, L. Gurdev, J. Kourtev

The double and single differential cross-sections with respect to positron and electron energies as well as the total cross-section of triplet production in the laboratory frame are calculated numerically in order to develop a Monte Carlo code for modelling electron-photon cascades in a soft photon field. To avoid numerical integration irregularities of the

F. P. Israel

A steep metallicity dependence of the CO-to-H2 conversion factor X of the form log X = 12.2 - 2.5 log[O]/[H], based on a sample of 20 (extra)galactic determinations, is presented and discussed. The apparently less steep dependence found from millimeter interferometer observations is explained within the context of photon-dominated regions.

Jin Koda, Yoshiaki Sofue, Keiichi Wada

We investigate the origin of a unified scaling relation in spiral galaxies. Observed spiral galaxies are spread on a plane in the three-dimensionallogarithmic space of luminosity L, radius R and rotation velocity V. The plane is expressed as $L \propto (V R)^α$ in I-passband, where $α$ is a constant. On the plane, observed galaxies are distributed in an elon

Nicholas B. Suntzeff

The past ten years have seen a tremendous increase in the number of Type Ia supernovae discovered and in the quality of the basic data presented. The cosmological results based on distances to Type Ia events have been spectacular, leading to statistically accurate values of the Hubble constant, Omega_M, and Omega_Lambda. However, in spite of the recent advan

Shibaji Banerjee, Sanjay K. Ghosh, Sibaji Raha

The Chandrasekhar limit for quark stars is evaluated from simple energy balance relations, as proposed by Landau for white dwarfs or neutron stars. It has been found that the limit for quark stars depends on, in addition to the fundamental constants, the Bag constant.

Bennett Link, Richard I. Epstein, James M. Lattimer

With the aim of constraining the structural properties of neutron stars and the equation of state of dense matter, we study sudden spin-ups, glitches, occurring in the Vela pulsar and in six other pulsars. We present evidence that glitches represent a self-regulating instability for which the star prepares over a waiting time. The angular momentum requiremen

Stuart D. Wick, Thomas W. Kephart, Thomas J. Weiler, Peter L. Biermann

Any early universe phase transition occurring after inflation has the potential to populate the universe with relic magnetic monopoles. Observations of galactic magnetic fields, as well as observations matched with models for extragalactic magnetic fields, lead to the conclusion that monopoles of mass $\lsim 10^{15}$ GeV are accelerated in these fields to re

M. S. Spector, S. K. Prasad, B. T. Weslowski, R. D. Kamien

Chiral twisting of the molecular orientation within the layer of a smectic-A liquid crystal has been investigated using circular dichroism spectroscopy. The results indicate that a rotation of the layers away from the alignment direction is induced by the surface electroclinic effect. This leads to an interfacial region where the molecular director twists fr

Ted Jacobson

Trans-Planckian redshifts in cosmology and outside black holes may provide windows on a hypothetical short distance cutoff on the fundamental degrees of freedom. In cosmology, such a cutoff seems to require a growing Hilbert space, but for black holes, Unruh&#39;s sonic analogy has given rise to both field theoretic and lattice models demonstrating how such

Nathan Berkovits

A classical action for open superstring field theory has been proposed which does not suffer from contact term problems. After generalizing this action to include the non-GSO projected states of the Neveu-Schwarz string, the pure tachyon contribution to the tachyon potential is explicitly computed. The potential has a minimum of $V = -{1\over{32 g^2}}$ which

V. M. Fomin, J. T. Devreese, V. Bruyndoncx, V. V. Moshchalkov

We have generalized the network approach to include the effects of short-range imperfections in order to analyze recent experiments on mesoscopic superconducting double loops. The presence of weakly scattering imperfections causes gaps in the phase boundary $B(T)$ or $Φ(T)$ for certain intervals of $T$, which depend on the magnetic flux penetrating each loop

E. Kiritsis, N. A. Obers, B. Pioline

A detailed understanding of instanton effects for half-BPS couplings is pursued in theories with 16 supersymmetries. In particular, we investigate the duality between heterotic string on $T^4$ and type IIA on $K_3$ at the $T^4/Z_2$ orbifold point, as well as their higher and lower dimensional versions. We present a remarkably clean quantitative test of the d

Klaus Behrndt, Sergei Gukov

Compactification of M theory in the presence of G-fluxes yields N=2 five-dimensional gauged supergravity with a potential that lifts all supersymmetric vacua. We derive the effective superpotential directly from the Kaluza-Klein reduction of the eleven-dimensional action on a Calabi-Yau three-fold and compare it with the superpotential obtained by means of c

Stefan Schroeer, Bernd Siebert

We classify irreducible d-semistable degenerations of primary Kodaira surfaces. As an application we construct a canonical completion for the moduli space of primary Kodaira surfaces.

M. A. Grigoriev, A. M. Semikhatov, I. Yu. Tipunin

In the BRST quantization of gauge theories, the zero locus $Z_Q$ of the BRST differential $Q$ carries an (anti)bracket whose parity is opposite to that of the fundamental bracket. We show that the on-shell BFV/BV gauge symmetries are in a 1:1 correspondence with Hamiltonian vector fields on $Z_Q$, and observables of the BRST theory are in a 1:1 correspondenc

N. N. Nikolaev, J. Speth, V. R. Zoller

High-energy virtual photon-virtual photon scattering can be viewed as interaction of small size color dipoles from the beam and target photons, which makes $γ^{*}γ^{*}, γ^{*}γ$ scattering at high energies (LEP, LEP200 & NLC) an indispensable probe of short distance properties of the QCD pomeron exchange. Based on the color dipole representation, we investiga

A. V. Efremov, M. Polyakov, K. Goeke, D. Urbano

Using the recent experimental data on the left right asymmetry in fragmentation of transversely polarized quarks and the theoretical calculation of the proton transversity distribution in the effective chiral quark soliton model we explain the azimuthal asymmetries in semi-inclusive hadron production on longitudinal (HERMES) and transversely (SMC) polarized

Victor Yakhot

Numerical and physical experiments on two-dimensional (2d) turbulence show that the differences of transverse components of velocity field are well described by a gaussian statistics and Kolmogorov scaling exponents. In this case the dissipation fluctuations are irrelevant in the limit of small viscosity. In general, one can assume existence of critical spac

Doron Cohen, Tsampikos Kottos

We study a classically chaotic system which is described by a Hamiltonian $H(Q,P;x)$ where $(Q,P)$ are the canonical coordinates of a particle in a 2D well, and $x$ is a parameter. By changing $x$ we can deform the `shape&#39; of the well. The quantum-eigenstates of the system are $|n(x)>$. We analyze numerically how the parametric kernel $P(n|m)= |<n(x)|m(x

Pablo. A. Ferrari, Christian Maes, Laura Ramos, Frank Redig

We model the behavior of a big (Brazil) nut in a medium of smaller nuts with a stochastic asymmetric simple exclusion dynamics of a polymer-monomer lattice system. The polymer or `rod&#39; can move up or down in an external negative field, occupying N horizontal lattice sites where the monomers cannot enter. The monomers (at most one per site) or `fluid part

D. Melikhov, B. Stech

We calculate the form factors for weak decays of $B_{(s)}$ and $D_{(s)}$ mesons to light pseudoscalar and vector mesons. To reveal the intimate connection between different decay modes and to be able to perform the calculations in the full physical $q^2$-region we use a relativistic dispersion approach based on the constituent quark picture. This approach gi

T. Scopigno, U. Balucani, G. Ruocco, F. Sette

New inelastic X-ray scattering experiments have been performed in liquid lithium at two different temperatures: T=475 K (slightly above the melting point) and 600 K. Taking advantage of the absence of any kinematical restriction and incoherent contribution, and pushing the instrumental resolution up to 1.5 meV, it was possible to perform an accurate investig

M. Masip

The presence of an extra dimension of size R\equiv M_c^{-1} introduces corrections of order (μ/M_c)αto the gauge and Yukawa couplings and accelerates their running at scales μlarger than M_c. This could result in a grand unification scale M_X\approx 20 M_c. We study the corrections at the two-loop level. We find corrections of order (μ/M_c)α^2 for the gauge

Haye Hinrichsen

Recently Carlon et. al. investigated the critical behavior of the pair contact process with diffusion [cond-mat/9912347]. Using density matrix renormalization group methods, they estimate the critical exponents, raising the possibility that the transition might belong to the same universality class as branching annihilating random walks with even numbers of

S. Rouziere, S. Ravy, J. -P. Pouget, S. Brazovskii

We present an x-ray diffraction study of the Vanadium-doped blue bronze K0.3(Mo0.972V0.028)O3. At low temperature, we have observed both an intensity asymmetry of the +-2kF satellite reflections relative to the pure compound, and a profile asymmetry of each satellite reflections. We show that the profile asymmetry is due to Friedel oscillation around the V s

A. I. Chernykh, M. G. Stepanov

We consider 1D Burgers equation driven by large-scale white-in-time random force. The tails of the velocity gradients probability distribution function (PDF) are analyzed by saddle-point approximation in the path integral describing the velocity statistics. The structure of the saddle-point (instanton), that is velocity field configuration realizing the maxi

E. Korutcheva, A. -M. Turiel, I. Markov

The formation of coherently strained three-dimensional islands on top of the wetting layer in Stranski-Krastanov mode of growth is considered in a model in 1+1 dimensions accounting for the anharmonicity and non-convexity of the real interatomic forces. It is shown that coherent 3D islands can be expected to form in compressed rather than in expanded overlay