June 2000 arXiv papers — page 16

Philip A. Pinto, Ronald G. Eastman

Observations of type Ia supernovae at high redshifts have become an important tool for studying the geometry of the universe. The relation between the duration of the peak phase of a type Ia supernova's lightcurve and its luminosity (broader is brighter) forms the cornerstone of this measurement, yet it is a purely empirical relation. In this paper we sh

S. L. Bridle, I. Zehavi, A. Dekel, O. Lahav

We compare and combine likelihood functions of the cosmological parameters Omega_m, h and sigma_8, from peculiar velocities, CMB and type Ia supernovae. These three data sets directly probe the mass in the Universe, without the need to relate the galaxy distribution to the underlying mass via a "biasing" relation. We include the recent results from t

I. Waddington, R. A. Windhorst, J. S. Dunlop, D. C. Koo

The results are presented of an extensive programme of optical and infrared imaging of radio sources in a complete subsample of the Leiden-Berkeley Deep Survey. The LBDS Hercules sample consists of 72 sources observed at 1.4 GHz, with flux densities S(1.4) >= 1.0 mJy, in a 1.2 deg^2 region of Hercules. This sample is almost completely identified in the g, r,

K. Agashe, N. G. Deshpande, G. -H. Wu

In models with large extra dimensions and TeV scale quantum gravity, small (Dirac) neutrino masses can be obtained naturally if the right-handed neutrino propagates in the extra dimensions. In this scenario, with 2 Higgs doublets, we show that the decay of charged Higgs into {\em left-handed} charged lepton (say τ) and right-handed neutrino can be significan

A. A. Louis, P. G. Bolhuis, J. P. Hansen, E. J. Meijer

We map dilute or semi-dilute solutions of non-intersecting polymer chains onto a fluid of ``soft'' particles interacting via a concentration dependent effective pair potential, by inverting the pair distribution function of the centers of mass of the initial polymer chains. A similar inversion is used to derive an effective wall-polymer potential; th

Igor R. Klebanov, Juan Maldacena

We study some aspects of open string theories on D-branes with critical electric fields. We show that the massless open string modes that move in the direction of the electric field decouple. In the 1+1 dimensional case the dual theory is U(N) SYM with electric flux, and the decoupling of massless open strings is dual to the decoupling of the U(1) degrees of

T. C. Ralph, W. J. Munro, R. E. S. Polkinghorne

We show theoretically that Bell-type correlations can be observed between continuous variable measurements performed on a parametric source. An auxiliary measurement, performed on the detection environment, negates the possibility of constructing a local realistic description of these correlations.

Xiangdong Ji, Wei Lu, Jonathan Osborne, Xiaotong Song

We consider the one-loop factorization of the simplest twist-three process: inclusive deep-inelastic scattering of longitudinally-polarized leptons on a transversely-polarized nucleon target. By studying the Compton amplitudes for certain quark and gluon states at one loop, we find the coefficient functions for the non-singlet twist-three distributions in th

Aneesh V. Manohar, Joan Soto, Iain W. Stewart

Nonrelativistic bound states have two low energy scales, a soft scale mu_S of order mv and an ultrasoft scale mu_U of order mv^2. In two-stage running, the soft and ultrasoft scales are lowered from m to mv, and then the ultrasoft scale is lowered from mv to mv^2. In one-stage running, the two scales are lowered in a correlated way using a subtraction veloci

D. G. Richards

Lattice Gauge Theory enables an ab initio study of the low-energy properties of Quantum Chromodynamics, the theory of the strong interaction. I begin these lectures by presenting the lattice formulation of QCD, and then outline the benchmark calculation of lattice QCD, the light-hadron spectrum. I then proceed to explore the predictive power of lattice QCD,

M. Batista, R. J. M. Covolan, J. Montanha

In this paper we present a combined analysis of the H1 data on leading baryon and diffractive structure functions from DIS, which are handled as two components of the same semi-inclusive process. The available structure function data are analyzed in a series of fits in which three main exchanges are taking into account: pomeron, reggeon and pion. For each of

Fabricio Toscano, Marcus A. M. de Aguiar, Alfredo M. Ozorio de Almeida

We propose a picture of Wigner function scars as a sequence of concentric rings along a two-dimensional surface inside a periodic orbit. This is verified for a two-dimensional plane that contains a classical orbit of a Hamiltonian system with two degrees of freedom. The orbit is hyperbolic and the classical Hamiltonian is ``softly chaotic'' at the en

F. Finkel, A. Gonzalez-Lopez, A. L. Maroto, M. A. Rodriguez

We show that the most general inflaton potential in Minkowski spacetime for which the differential equation for the Fourier modes of the matter fields reduces to Lamé's equation is of the form $V(ϕ)= λϕ^4/4+Kϕ^2/2+μ/(2ϕ^2)+V_0$. As an application, we study the preheating phase after inflation for the above potential with K=0 and arbitrary $λ,μ>0$. For ce

L. L. Bonilla

The Chapman-Enskog method of kinetic theory is applied to two problems of synchronization of globally coupled phase oscillators. First, a modified Kuramoto model is obtained in the limit of small inertia from a more general model which includes ``inertial'' effects. Second, a modified Chapman-Enskog method is used to derive the amplitude equation for

I. Jack, D. R. T. Jones

We explore, in the MSSM context, an extension of the Anomaly Mediated Supersymmetry Breaking solution for the soft scalar masses that is possible if the underlying theory has a gauged R-symmetry. The slepton mass problem characteristic of the scenario is resolved, and a context for the explanation of the fermion mass hierarchy provided.

Almut Beige, William J. Munro, Peter L. Knight

Previous work on Bell's inequality realised in the laboratory has used entangled photons. Here we describe how entangled atoms can violate Bell's inequality, and how these violations can be measured with a very high detection efficiency. We first discuss a simple scheme based on two-level atoms inside a cavity to prepare the entangled state. We then

F. A. Aharonian, A. K. Konopelko, H. J. Voelk, H. Quintana

We discuss the concept and the performance of a powerful future ground-based astronomical instrument - a stereoscopic array of several large imaging atmospheric Cherenkov telescopes installed at a very high mountain elevation of about 5 km a.s.l. or more - for the study of the gamma-ray sky at energies from several GeV to 100 GeV.

B. C. Allanach, K. Odagiri, M. A. Parker, B. R. Webber

A spectrum of massive graviton states is present in several recent theoretical models that include extra space dimensions. In some such models the graviton states are well separated in mass, and can be detected as resonances in collider experiments. The ability of the ATLAS detector at the Large Hadron Collider to identify such states and measure their prope

P. G. Radaelli, R. M. Ibberson, D. N. Argyriou, H. Casalta

Mesoscopic (500-2000 Angstrom) and microscopic (5-20 Angstrom) phase segregation with temperature and magnetic field was studied in the model manganite Pr0.7Ca0.3MnO3 by high-resolution neutron diffraction and inelastic neutron scattering. Intra-granular strain-driven mesoscopic segregation between two insulating phases, one of which is charge ordered (CO),

K. Rajesh Nayak, M. A. H. MacCallum, C. V. Vishveshwara

As an example of a black hole in a non-flat background a composite static spacetime is constructed. It comprises a vacuum Schwarzschild spacetime for the interior of the black hole across whose horizon it is matched on to the spacetime of Vaidya representing a black hole in the background of the Einstein universe. The scale length of the exterior sets a maxi

ZEUS Collaboration

The exclusive electroproduction of omega mesons, ep -> e omega p, has been studied in the kinematic range 3<Q^2<20 GeV^2, 40<W<120 GeV and |t|<0.6 GeV^2 with the ZEUS detector at HERA using an integrated luminosity of 37.7 pb^{-1}. The omega mesons were identified via the decay omega -> pi^+pi^-pi^0. The exclusive (ep -> e omega p) cross section in the above

Cenalo Vaz, Louis Witten

We quantize the Reissner-Nordström black hole using an adaptation of Kuchař&#39;s canonical decomposition of the Kruskal extension of the Schwarzschild black hole. The Wheeler-DeWitt equation turns into a functional Schroedinger equation in Gaussian time by coupling the gravitational field to a reference fluid or dust. The physical phase space of the theory

O. Petruk

A new possibility to explain the nature of thermal X-ray composites (TXCs), i.e. a class of supernova remnants (SNRs) with a thermal X-ray centrally-filled morphology within a radio shell, as a projection effect of the 2- or 3-dimensional shell-like SNR evolved in a nonuniform medium with scale-height <10 pc is proposed. Both X-ray and radio morphologies, as

L. Derome, M. Buenerd, A. Barrau, A. Bouchet

The high flux proton component observed by AMS below the geomagnetic cutoff can be well accounted for by assuming these particles to be secondaries originating from the interaction of Cosmic Ray protons with the atmosphere. Simulation results are reported

E. I. Guendelman

For superstrings, the consequences of replacing the measure of integration $\sqrt{-γ}d^2 x$ in the Polyakov&#39;s action by $Φd^2 x$ where $Φ$ is a density built out of degrees of freedom independent of the metric $γ_{ab}$ defined in the string are studied. As in Siegel reformulation of the Green Schwarz formalism the Wess-Zumino term is the square of supers

Tony Rothman

Liberati, Rothman and Sonego have recently showed that objects collapsing into extremal Reissner-Nordstrom black holes do not behave as thermal objects at any time in their history. In particular, a temperature, and hence thermodynamic entropy, are undefined for them. I demonstrate that the analysis goes through essentially unchanged for Kerr black holes.

Zhi-zhong Xing

We show that the CP-violating effect in K^0 vs \bar K^0-->π^+π^-π^0 decays differs from that in K_{\rm L}-->π^+π^-, K_{\rm L}-->π^0π^0 or the semileptonic K_{\rm L} transitions, if there exists CPT violation in K^0-\bar{K}^0 mixing. A delicate measurement of this difference in the KTeV experiment and at the ϕfactory will provide a new test of CPT symmetry in

Silvio Franz, Giorgio Parisi

We explore the consequences of Replica Symmetry Breaking at zero temperature. We introduce a repulsive coupling between a system and its unperturbed ground state. In the Replica Symmetry Breaking scenario a finite coupling induces a non trivial overlap probability distribution among the unperturbed ground state and the one in presence of the coupling. We fin

Wu-Jun Huo

We investigate the mass differences $ΔM_{B_{d,s}}$ in the mixing $B^0_{d,s}-\bar B^0_{d,s}$ with a new up-like quark $t^{\prime}$ in the sequential fourth generation model. We give the basic formulae for $ΔM_{B_{d,s}}$ in this model and obtain two kinds of numerical results of $ΔM_{B_{s}}$ which is the function of $m_{t^{\prime}}$. We find that one of our re

Federico Fontana, Davide Rocchesso

An elastic ideal 2D propagation medium, i.e., a membrane, can be simulated by models discretizing the wave equation on the time-space grid (finite difference methods), or locally discretizing the solution of the wave equation (waveguide meshes). The two approaches provide equivalent computational structures, and introduce numerical dispersion that induces a

Dinesh Kumar Srivastava, Bikash Sinha

The production of single photons in $Pb+Pb$ collisions at the CERN SPS as measured by the WA98 experiment is analysed. A quark gluon plasma is assumed to be formed initially, which expands, cools, hadronizes, and undergoes freeze-out. A rich hadronic equation of state is used and the transverse expansion of the interacting system is taken into account. The r

K. J. Resch, J. S. Lundeen, A. M. Steinberg

It is often asserted that quantum effects can be observed in coincidence detection rates or other correlations, but never in the rate of single-photon detection. We observe nonclassical interference in a singles rate, thanks to the intrinsic nonlinearity of photon counters. This is due to a dependence of the effective detection efficiency on the quantum stat

M. U. Karelin, A. M. Lazaruk

For configurational space of arbitrary dimension a strict form of the uncertainty principle has been obtained, which takes into account the dependence of inequality limit on the effective number of pure states present in given statistical mixture. It is shown that in a state with minimal uncertainty the density operators eigenfunctions coincide with the stat

C. Y. Chen

On contrary to the customary thought, the well-known ``lemma&#39;&#39; that the distribution function of a collisionless Boltzmann gas keeps invariant along a molecule&#39;s path represents not the strength but the weakness of the standard theory. One of its consequences states that the velocity distribution at any point is a condensed ``image&#39;&#39; of a

Michael Gedalin

We show that oscillations are excited in a complex system under the influence of the external force, if the parameters of the system experience rapid change due to the changes in its internal structure. This excitation is collision-like and does not require any phase coherence or periodicity. The change of the internal structure may be achieved by other mean

C. B. Das, S. Das Gupta, S. K. Samaddar

Microcanonical calculations are no more difficult to implement than canonical calculations in the Lattice Gas Model. We report calculations for a few observables where we compare microcanonical model results with canonical model results.

L. Hlavaty

Field equations for generalized principle models with nonconstant metric are derived and ansatz for their Lax pairs is given. Equations that define the Lax pairs are solved for the simplest solvable group. The solution is dependent on one free variable that can serve as the spectral parameter. Painleve analysis of the resulting model is performed and its par

G. Giachetta, L. Mangiarotti, G. Sardanashvily

Cohomology of the variational bicomplex in the calculus of variations in classical field theory are computed in the class of exteriror forms of finite jet order. This provides a solution of the global inverse problem of the finite order calculus of variations.

J. E. Nelson, R. F. Picken

The notion of quantum matrix pairs is defined. These are pairs of matrices with non-commuting entries, which have the same pattern of internal relations, q-commute with each other under matrix multiplication, and are such that products of powers of the matrices obey the same pattern of internal relations as the original pair. Such matrices appear in an appro

Jan Wierzba

We consider birational projective contractions f:X -> Y from a smooth symplectic variety X over the complex numbers. We first show that exceptional rational curves on X deform in a family of dimension at least 2n-2. Then we show that these contractions are generically coisotropic, provided X is projective. Then we specialize to contractions with 1-dimensiona

Stephen A. DiPippo, Everett W. Howe

In this paper we prove several theorems about abelian varieties over finite fields by studying the set of monic real polynomials of degree 2n all of whose roots lie on the unit circle. In particular, we consider a set V_n of vectors in R^n that give the coefficients of such polynomials. We calculate the volume of V_n and we find a large easily-described subs

T. Chinburg, G. Pappas, M. J. Taylor

We conjecture that the logarithm of the absolute value of the constant in the functional equation of the Hasse-Weil L-function of a variety X over Z is equal to a certain Arakelov de Rham Euler characteristic of X. This generalizes the fact that the constant in the functional equation of the zeta function of a number field is the square root of the discrimin

Robert Friedman, John W. Morgan

Let G be a complex reductive group and let C be a smooth curve of genus at least one. We prove a converse to a theorem of Atiyah-Bott concerning the stratification of the space of holomorphic G-bundles on C. In case the genus of C is one, we establish that one has a stratification in the strong sense. The paper concludes with a characterization of the minima

Michael Farber

We give topological lower bounds on the number of periodic and closed trajectories in strictly convex smooth billiards. We use variational reduction admitting a finite group of symmetries and apply topological approach based on equivariant Morse and Lusternik - Schnirelman theories. The paper continues results published in math.DG/9911226 and math.DG/0006049

Jifeng Yang

A tentative proposal is demonstrated that there is a natural strategy to get rid of unphysical (UV) infinities in QFTs if one adopts the modern standard point of view that a fundamental theory that is complete and well-defined in all respects underlies the QFTs. This simple strategy works in principle for any interaction model and space-time dimension. It pr

George Siopsis

We discuss the quantization of a particle near an extreme Reissner-Nordstrom black hole in the canonical formalism. This model appears to be described by a Hamiltonian with no well-defined ground state. This problem can be circumvented by a redefinition of the Hamiltonian due to de Alfaro, Fubini and Furlan (DFF). We show that the Hamiltonian with no ground

Bunji Sakita

Reminiscences of Bunji Sakita.

Anastasia Doikou

We generalise the fusion procedure for the $A_{\n-1}^{(1)}$ open spin chain ($\n>2$) and we show that the transfer matrix satisfies a crossing property. We use these results to solve the $A_{\n-1}^{(1)}$ open spin chain with $U_{q} (SU(\n))$ symmetry by means of the analytical Bethe ansatz method. Our results coincide with the known ones obtained by means of

M. Blagojevic, M. Vasilic

We study gauge properties of the general teleparallel theory of gravity, defined in the framework of Poincare gauge theory. It is found that the general theory is characterized by two kinds of gauge symmetries: a specific gauge symmetry that acts on Lagrange multipliers, and the standard Poincare gauge symmetry. The canonical generators of these symmetries a

L. Martinovic, J. P. Vary

Spontaneous symmetry breaking is studied within a simple version of the light-front sigma model with fermions. Its vacuum structure is derived by an implementation of global symmetries in terms of unitary operators in a finite volume with periodic fermi field. Due to the dynamical fermion zero mode, the vector and axial U(1) charges do not annihilate the lig

S. Gardner

Isospin-breaking effects, in particular those associated with electroweak-penguin contributions and pi0-eta,eta&#39; mixing, have long been known to affect the Standard Model prediction of Re(epsilon&#39;/epsilon) in a significant manner. We have found an heretofore unconsidered isospin-violating effect of importance; namely, the u-d quark mass difference ca

James M. Cline, Michael Joyce, Kimmo Kainulainen

We re-examine the generation of the baryon asymmetry in the minimal supersymmetric standard model (MSSM) during the electroweak phase transition. We find that the dominant source for baryogenesis arises from the chargino sector. The CP-violation comes from the complex phase in the mu parameter, which provides CP-odd contributions to the particle dispersion r

Dmitri Grigoriev

Two recent scenarios of preheating-related baryogenesis are compared within the framework of Abelian Higgs model in (1+1) dimensions. It is shown that they shift baryon number in opposite directions. Once both scenarios can realize simultaneously as overlapped stages of the same physical process, even the sign of net generated asymmetry becomes dependent on

Luca Trentadue, Michela Verbeni

We discuss a connection between axial anomaly and polarized radiative processes. By comparison with the corresponding unpolarized cases, we consider some physical outputs for the $π^+$ and $Z^0$ polarized radiative decays. We analyse in detail the pattern of mass singularity cancellation.

R. Mohanta, A. K. Giri, M. P. Khanna

Using a theoretical framework based on the next-to-leading order QCD improved effective Hamiltonian, we have estimated the branching ratios and asymmetry parameters for the two body charmless nonleptonic decay modes of $Λ_b$ baryon i.e. $Λ_b \to p (π/ρ),~p(K/K^*)$ and $Λ(π/ρ)$, within the framework of generalized factorization. The nonfactorizable contributi

Michael T. Anderson

We describe some relations between the long-time asymptotic behavior of the vacuum Einstein evolution equations and the geometrization of 3-manifolds. These relations are expressed in terms of evolution of CMC hypersurfaces in the vacuum space-time.Some results are also obtained on the singularity avoidance of CMC foliations. In addition, the paper describes

Ozay Gurtug, Mustafa Halilsoy

The quasiregular singularities (horizons) that form in the collision of cross polarized electromagnetic waves are, as in the linear polarized case unstable. The validity of the Helliwell-Konkowski stability conjecture is tested for a number of exact back-reaction cases. In the test electromagnetic case the conjecture fails to predict the correct nature of th

Z. L. Xiao, E. Y. Andrei, P. Shuk, M. Greenblat

We report on the observation of two types of current driven transitions in metastable vortex lattices. The metastable states, which are missed in usual slow transport measurements, are detected with a fast transport technique in the vortex lattice of undoped 2H-NbSe$_2$. The transitions are seen by following the evolution of these states when driven by a cur

Z. Ropka, R. J. Radwanski

It is shown that the d8 electron system occurring in the Ni2+ ion can have the non-magnetic ground state in the atomic scale formed by the Jahn-Teller effect. The tetragonal/trigonal off-cubic lattice distortion for the octahedral site causes the splitting of the triplet 3A2g into a singlet-doublet structure with the non-magnetic singlet lying lower provided

M. Valin-Rodriguez, Antonio Puente, Llorens Serra

We present calculations within density functional theory of the ground state and collective electronic oscillations in small two-dimensional quantum rings. No spatial symmetries are imposed to the solutions and, as in a recent contribution, a transition to a broken symmetry solution in the intrinsic reference frame for an increasingly narrow ring is found. T

Jan Zaanen, Zohar Nussinov

One of the central problems in High T_{c} superconductivity is to reconcile the abundant evidence for stripe-like physics at `short&#39; distances with the equally convincing evidence for BCS like physics at large distance scales (the `nodal fermions&#39;). Our central hypothesis is that the duality notion applies: the superconductor should be viewed as a co

Navot Israeli, Daniel Kandel

The relaxation process of one dimensional surface modulations is re-examined. Surface evolution is described in terms of a standard step flow model. Numerical evidence that the surface slope, D(x,t), obeys the scaling ansatz D(x,t)=alpha(t)F(x) is provided. We use the scaling ansatz to transform the discrete step model into a continuum model for surface dyna

R. Pastor-Satorras, J. M. Rubi

Standard models of sequential adsorption are implicitly formulated in a {\em scale invariant} form, by assuming adsorption on an infinite surface, with no characteristic length scales. In real situations, however, involving complex surfaces, intrinsic length scales may be relevant. We present an analytic model of continuous random sequential adsorption, in w

Sergey V. Kuplevakhsky

We solve the problem of exact minimization of the Lawrence-Doniach (LD) free-energy functional in parallel magnetic fields. We consider both the infinite in the layering direction case (the infinite LD model) and the finite one (the finite LD model). We prove that, contrary to a prevailing view, the infinite LD model does not admit solutions in the form of i

Igor S. Aranson, Lev S. Tsimring

We develop a continuum description of partially fluidized granular flows. Our theory is based on the hydrodynamic equation for the flow coupled with the order parameter equation which describes the transition between flowing and static components of the granular system. This theory captures important phenomenology recently observed in experiments with granul

Fred Hamann

Strong absorption lines are common in rest-frame UV spectra of AGNs due to a variety of resonant transitions, for example the HI Lyman series lines (most notably Ly-alpha 1216) and high-ionization doublets like CIV 1549,1551. The lines are called ``intrinsic&#39;&#39; if the absorbing gas is physically related to the AGN, e.g. if the absorber resides broadly

K. Z. Stanek, J. Kaluzny, A. Wysocka, I. Thompson

(Abridged) We analyze the UBVI color-magnitude diagrams towards the Galactic bulge in a relatively low-reddening region of Baade&#39;s Window. The dereddened red giant branch is very wide [~1.0 mag in (U-B)_0 and ~0.4 mag in (B-V)_0 and (V-I)_0], indicating a significant dispersion of stellar metallicities, which by comparison with the theoretical isochrones

F. Courbin, C. Lidman, G. Meylan, J. -P. Kneib

(Abridged) A new technique for the spatial deconvolution of spectra is applied to near-IR (0.95 - 2.50 micron) NTT/SOFI spectra of the lensed, radio-quiet quasar HE 1104-1805. The continuum of the lensing galaxy is revealed between 1.5 and 2.5 micron. It is used in combination with previous optical and IR photometry to infer a plausible redshift in the range

Sidney van den Bergh

Globular cluster systems exhibit a bewildering variety of characteristics. No single scenario appears to be able to account for the wide range of specific globular cluster frequencies that are observed in galaxies of various types. The fraction of all star formation that produces massive bound clusters differs from galaxy to galaxy, and (in some cases) appea

R. G. Abraham

Establishing the morphological history of ordinary galaxies was one of the original goals for the Hubble Space Telescope, and remarkable progress toward achieving this this goal has been made. How much of this progress has been at the expense of the Hubble sequence? As we probe further out in redshift space, it seems time to re-examine the underlying signifi

M. Vestergaard, B. J. Wilkes, P. D. Barthel

We present evidence that the high-velocity CIV lambda 1549 emission line gas of radio-loud quasars may originate in a disk-like configuration, in close proximity to the accretion disk often assumed to emit the low-ionization lines. For a sample of 36 radio-loud z~2 quasars we find the 20--30% peak width to show significant inverse correlations with the fract

R. Ignace, M. A. Hendry

We derive a method for inverting emission line profiles formed in supernova ejecta. The derivation assumes spherical symmetry and homologous expansion (i.e., $v(r) \propto r$), is analytic, and even takes account of occultation by a pseudo-photosphere. Previous inversion methods have been developed which are restricted to optically thin lines, but the partic

A. D. Dolgov

A brief review of neutrino anomalies in particle physics and of the role played by neutrinos in cosmology and astrophysics is presented. The main part of the talk is dedicated to the impact of neutrinos and in particular of neutrino oscillations on BBN and to a possible spatial variation of primordial abundances.

A. Kogut, G. Hinshaw

We use a simple model to investigate the effect of polarized Galactic foreground emission on the ability of planned CMB missions to detect and model CMB polarization. Emission from likely polarized sources (synchrotron and spinning dust) would dominate the polarization of the microwave sky at frequencies below 90 GHz if known Galactic foregrounds are at leas

D. I. Makarov, I. D. Karachentsev, A. N. Burenkov

Rotational curves are measured for almost complete sample of 308 northern spiral galaxies using the 6-m telescope. For observations we selected edge-on galaxies from RFGC catalog with apparent axial ratio a/b>8, angular diameter a<2&#39;, and declinations delta>+38deg above the Arecibo belt. About 97% of the galaxies are detected in the H-alpha line. For the

Hideki Asada, Masumi Kasai

It is known that the rotation of a gravitational lens affects properties of images. We consider an inverse problem: If the lens is dark, can we infer its rotation from the observed images? We find that, up to the first order in the gravitational constant G, a rotating lens is not distinguishable from a non-rotating one. The quadrupole contribution to the def

Y. -S. Park, J. -F. Panis, N. Ohashi, M. Choi

We present the aperture synthesis imaging of C3H2 2_{12}-1_{01} and HCO+ 1-0 lines and of continuum emission at 3.4 mm toward the class 0 young stellar object, IRAS 18148-0440 in the L483 molecular cloud. The continuum emission is detected at the IRAS position at a level of 16 mJy, indicating a compact source with a 0.13 solar mass. The C3H2 delineates an en

S. S. Allam, D. L. Tucker

We have recently extracted a catalog of compact groups of galaxies (CGs) from the Las Campanas Redshift Survey. This catalog of Las Campanas Compact Groups (LCCGs) contains 76 CGs with a median redshift of z_med = 0.08. The physical properties of these CGs are similar to those from the Hickson (1982) and the Barton et al. (1996) catalogs. Here, we present an

B. O&#39;Halloran, L. Metcalfe, M. Delaney, B. McBreen

The interacting system Arp 284 consisting of the Wolf-Rayet galaxy NGC 7714 and its irregular companion NGC 7715 was observed using the Infrared Space Observatory. Deconvolved ISOCAM maps of the galaxies using the 14.3, 7.7 and 15 micron LW3, LW6 and LW9 filters, along with ISOPHOT spectrometry of the nuclear region of NGC 7714 were obtained and are presente

Supriya Kar

We investigate the open string modes, describing the world-volume of a D p-brane, for its cyclic symmetry in presence of a magnetic field. It is argued that the constant coordinate modes receive non-perturbative correction. We show that they introduce the notion of noncommutativity on the D p-brane world-volume and make it UV-renormalizable. An analogy betwe

R. Hofmann, T. ter Veldhuis

Generalized Wess-Zumino models which admit topologically non-trivial BPS saturated configurations along one compact, spatial dimension are investigated in various dimensions of space-time. We show that, in a representative model and for sufficiently large circumference, there are BPS configurations along the compact dimension containing an arbitrary number o

Cristina Manuel

Present computations of the gap of color superconductivity in weak coupling assume that the quarks which participate in the condensation process are infinitely long-lived. However, the quasiparticles in a plasma are characterized by having a finite lifetime. In this article we take into account this fact to evaluate its effect in the computation of the color

Boris Kerbikov, Frank Tabakin

We examine the photoproduction of the light scalar mesons $f_0$-$a_0 (980)$ with emphasis on isospin-violating $f_0$ and $a_0$ mixing due to the mass difference between neutral and charged kaons. General forms for the invariant amplitude for scalar meson photoproduction are derived, which yield expressions for the invariant mass distribution of the final mes

M. Matsuura, H. Hiraka, K. Yamada, Y. Endoh

Magnetic phase diagram of NiS2-xSex has been reexamined by systematic studies of electrical resistivity, uniform magnetic susceptibility and neutron diffraction using single crystals grown by a chemical transport method. The electrical resistivity and the uniform magnetic susceptibility exhibit the same feature of temperature dependence over a wide Se concen

Deog Ki Hong

We show that radiatively generated Majorana mass for antiquarks is same as the Cooper-pair gap. We then calculate the electromagnetic corrections to mass of particles in the color-flavor locking phase of QCD at high density. The mass spectrum forms multiplets under $SU(2)_V\times U(1)_V$. The charged pions and kaons get the electromagnetic mass which is prop

Mark Auslender, Eugene Kogan

We study density of states and conductivity of the doped double-exchange system, treating interaction of charge carriers both with the localized spins and with the impurities in the coherent potential approximation. It is shown that under appropriate conditions there is a gap between the conduction band and the impurity band in paramagnetic phase, while the

Bang-Rong Zhou

We reexamine physical causal propagators for scalar and pseudoscalar bound states at finite temperature in a chiral $U_L(1)\times U_R(1)$ NJL model, defined by four-point amputated functions subtracted through the gap equation, and prove that they are completely equivalent in the imaginary-time and real-time formalism by separating carefully the imaginary pa

A. Stolcke, K. Ries, N. Coccaro, E. Shriberg

We describe a statistical approach for modeling dialogue acts in conversational speech, i.e., speech-act-like units such as Statement, Question, Backchannel, Agreement, Disagreement, and Apology. Our model detects and predicts dialogue acts based on lexical, collocational, and prosodic cues, as well as on the discourse coherence of the dialogue act sequence.

U. V. Waghmare, Hanchul Kim, I. J. Park, Normand Modine

We discuss our new implementation of the Real-space Electronic Structure method for studying the atomic and electronic structure of infinite periodic as well as finite systems, based on density functional theory. This improved version which we call HARES (for High-performance-fortran Adaptive grid Real-space Electronic Structure) aims at making the method wi

M. Fujiwara, H. Akimune, A. M. van den Berg, M. Cribier

Discrete Gamow-Teller (GT) transitions, 176Yb-->176Lu at low excitation energies have been measured via the (3He,t) reaction at 450 MeV and at 0 degrees. For 176Yb, two low-lying states are observed, setting low thresholds Q(neutrino)=301 and 445 keV for neutrino capture. Capture rates estimated from the measured GT strengths, the simple two-state excitation

Osamu Inomoto, Shoichi Kai, Boris Malomed

We study motion of a phase transition front at a constant temperature between stable and metastable states in fluids with the universal Van der Waals equation of state (which is valid sufficiently close to the fluid&#39;s critical point). We focus on a case of relatively large metastability and low viscosity, when it can be shown analytically that no steadil

Martin Florig, Stephen J. Summers

We construct a new class of representations of the canonical commutation relations, which generalizes previously known classes. We perturb the infinitesimal generator of the initial Fock representation (i.e. the free quantum field) by a function of the field which is square-integrable with respect to the associated Gaussian measure. We characterize which suc

M. Gitik

The results of the previous version are impoved. This basically completes the study of consistency strength of various gaps between a strong limit singular cardinal of cofinality omega and its power under GCH type assumptions below.

Dylan Paul Thurston

We construct and prove a diagrammatic version of the Duflo isomorphism between the invariant subalgebra of the symmetric algebra of a Lie algebra and the center of the universal enveloping algebra. This version implies the original for metrized Lie algebras (Lie algebras with an invariant non-degenerate bilinear form). As an application of this isomorphism,

William Arveson

Given a commuting d-tuple $\bar T=(T_1,...,T_d)$ of otherwise arbitrary nonnormal operators on a Hilbert space, there is an associated Dirac operator $D_{\bar T}$. Significant attributes of the d-tuple are best expressed in terms of $D_{\bar T}$, including the Taylor spectrum and the notion of Fredholmness. In fact, {\it all} properties of $\bar T$ derive fr

Agapitos Hatzinikitas

We calculate the chiral anomaly in the neighbourhood of the fixed point space M_h which is constructed by the group action of a discrete symmetry h on a compact manifold M. The Feynman diagrams approach for the corresponding supersymmetric quantum mechanical system with twisted boundary conditions is used. The result we derive in this way agrees with the gen

Juan Fernando Ospina Giraldo

The Wess-Zumino action for generalized orientifold planes (GOp-planes) is presented and a series power expantion is realized from which processes that involves GOp-planes, RR-forms, gravitons and gaugeons, are obtained. Finally non-standard GOp-planes are showed.

L. A. Anchordoqui, M. Kirasirova, T. P. McCauley, T. Paul

We study the self-similar structure of electromagnetic showers and introduce the notion of the fractal dimension of a shower. Studies underway of showers in various materials and at various energies are presented, and the range over which the fractal scaling behaviour is observed is discussed. Applications to fast shower simulations and identification, parti

T. M. Aliev, M. Savci

A model-independent analysis for the exclusive, rare B -> pi^+ pi^- l^+ l^- decay is presented. The dependence of the various physically measurable asymmetries and CP violating asymmetry on the new Wilson coefficients is studied in detail. It is observed that different measurable quantiles are very sensitive to the different new Wilson coefficients, i.e., to

V. V. Kiselev, A. E. Kovalsky, A. K. Likhoded

In the framework of three-point QCD sum rules, the form factors for the semileptonic decays of B_c^+ -> B_s(B_s^*) l νare calculated with account for the Coulomb-like alpha_s/v-corrections in the heavy quarkonium. The generalized relations due to the spin symmetry of HQET/NRQCD for the form factors are derived at the recoil momentum close to zero. The nonlep