January 2002 arXiv papers — page 10

C. Schuster, U. Eckern

Using the density matrix renormalization group (DMRG) method, we study the quantum coherence in one-dimensional disordered Fermi systems. We consider in detail spinless fermions on a ring, and compare the influence of several kinds of impurities in a gapless and a dimerized, gapped system. In the translation-invariant system a so-called site-impurity, which

Pablo Minces

We show that multi-trace interactions can be consistently incorporated into an extended AdS/CFT prescription involving the inclusion of generalized boundary conditions and a modified Legendre transform prescription. We find new and consistent results by considering a self-contained formulation which relates the quantization of the bulk theory to the AdS/CFT

J. Goryo, M. Kohmoto

We consider Bloch electrons in the electromagnetic field and argue the relation between the Berry phase and the quantized Hall conductivity in three-dimension. The Berry phase we consider here is induced by the adiabatic change of the time-dependent vector potential. The relation has been shown in two-dimensional systems, and we generalize the relation in th

R. V. Tumanian

In work is considered average transverse dynamics of an electron beam in the autoresonant laser. It is shown, that in approach of the given external electromagnetic wave (small gain free electron laser) transverse emittance of a beam of the charged particles decreases. This for the first time found out effect can be used for cooling beams of various accelera

I. Kupcic

The three-component ab-plane optical conductivity of the high-T_c cuprates is derived using the gauge invariant response theory, and compared to the data previously obtained from the optical reflectivity measurements in the La_2CuO_4 based families. The valence electrons are described by the Emery three-band model with the antiferromagnetic correlations repr

Junegone Chay, Chul Kim

We consider a collinear effective theory of highly energetic quarks with energy E, interacting with collinear and soft gluons by integrating out collinear degrees of freedom to subleading order. The collinear effective theory offers a systematic expansion in power series of a small parameter lambda ~ p_{\perp}/E, where p_{\perp} is the transverse momentum of

Sigitas Ališauskas

The expressions of the coupling coefficients (3j-symbols) for the most degenerate (symmetric) representations of the orthogonal groups SO(n) in a canonical basis (with SO(n) restricted to SO(n-1)) and different semicanonical or tree bases [with SO(n) restricted to SO(n'})\times SO(n''), n'+n''=n] are considered, respectively, in conte

B. Demircioglu, S. Kuru, M. Onder, A. Vercin

As an extension of the intertwining operator idea, an algebraic method which provides a link between supersymmetric quantum mechanics and quantum (super)integrability is introduced. By realization of the method in two dimensions, two infinite families of superintegrable and isospectral stationary potentials are generated. The method makes it possible to perf

Ken-Ichi Tezuka

We construct Poisson brackets at boundaries of open strings and membranes with constant background fields which are compatible with their boundary conditions. The boundary conditions are treated as primary constraints which give infinitely many secondary constraints. We show explicitly that we need only two (the primary one and one of the secondary ones) con

Muge Boz, Namik K. Pak

We perform a detailed study of the electric and chromoelectric dipole coefficients in B -> X_s γdecay in a supersymmetric scheme with explicit CP violation. In our analysis, we adopt the minimal flavor violation scheme by taking into account the \tanβ-enhanced large contributions beyond the leading order. We show that the coefficients can deviate from the SM

Xin-Zhong Yan

We present a self-consistent approach to deal with the pairing-fluctuation effects in quasi-two-dimensional superconducting systems. Besides the Cooper pairs in the Bose-Einstein condensate, there are pairs occupying the excited states, which results in the predominant fluctuations. The low-lying excited states are the collective modes. On the basis of ladde

Samuel J. Lomonaco,, Louis H. Kauffman

The ultimate objective of this paper is to create a stepping stone to the development of new quantum algorithms. The strategy chosen is to begin by focusing on the class of abelian quantum hidden subgroup algorithms, i.e., the class of abelian algorithms of the Shor/Simon genre. Our strategy is to make this class of algorithms as mathematically transparent a

Jukka Maalampi, Nikolai Romanenko

We reconsider the single production of the doubly charged Higgs bosons Delta_R^{++} and Delta_L^{++} at the LHC and TEVATRON in the framework of the left-right symmetric model and the Higgs triplet model. We show that in the left-right symmetric model the production of Delta_R^{++} by Drell-Yan process via W_R exchange may give the dominant contribution. The

J. Pumplin, D. R. Stump, J. Huston, H. L. Lai

A new generation of parton distribution functions with increased precision and quantitative estimates of uncertainties is presented. This work significantly extends previous CTEQ and other global analyses on two fronts: (i) a full treatment of available experimental correlated systematic errors for both new and old data sets; (ii) a systematic and pragmatic

Satoshi Fujimoto

We investigate pseudo-gap phenomena realized in the BCS pairing model with a long but finite interaction range. We calculate the single-particle self-energy in all order exactly in the temperature range where the superconducting fluctuation propagator is Gaussian-like. It is found that vertex corrections to the self-energy which are discarded in the previous

Bernd Ammann, Robert Lauter, Victor Nistor

A manifold with a ``Lie structure at infinity'' is a non-compact manifold $M_0$ whose geometry is described by a compactification to a manifold with corners M and a Lie algebra of vector fields on M, subject to constraints only on $M \smallsetminus M_0$. The Lie structure at infinity on $M_0$ determines a metric on $M_0$ up to bi-Lipschitz equivalenc

Marc Henneaux, Cristian Martinez, Ricardo Troncoso, Jorge Zanelli

We consider 2+1 gravity minimally coupled to a self-interacting scalar field. The case in which the fall-off of the fields at infinity is slower than that of a localized distribution of matter is analyzed. It is found that the asymptotic symmetry group remains the same as in pure gravity (i.e., the conformal group). The generators of the asymptotic symmetrie

Ram K. Varma

It has been shown earlier that matter waves which are known to lie typically in the range of a few Angstrom, can also manifest in the macrodomain with a wave length of a few centimeters, for electrons propagating along a magnetic field. This followed from the predictions of a probability amplitude theory by the author in the classical macrodomain of the dyna

N. Debergh, J. Ndimubandi, B. Van den Bossche

We construct a general algorithm generating the analytic eigenfunctions as well as eigenvalues of one-dimensional stationary Schroedinger Hamiltonians. Both exact and quasi-exact Hamiltonians enter our formalism but we focus on quasi-exact interactions for which no such general approach has been considered before. In particular we concentrate on a generalize

G. S. Agarwal

We present a brief review of the impact of the Heisenberg uncertainty relations on quantum optics. In particular we demonstrate how almost all coherent and nonclassical states of quantum optics can be derived from uncertainty relations.

Miloslav Dusek, Vladimir Buzek

We discuss a possibility to build a programmable quantum measurement device (a "quantum multimeter"). That is, a device that would be able to perform various desired generalized, positive operator value measure (POVM) measurements depending on a quantum state of a "program register". As an example, we present a "universal state discrimina

S. I. J. Kurzeja, A. S. Parkins

Entanglement is a crucial resource in quantum information theory. We investigate the use of different forms of entangled states in continuous variable quantum teleportation, specifically the use of a finite-basis entanglement resource. We also consider the continuous variable teleportation of finite-basis states, such as qubits, and present results that poin

Amnon Kislev, Lev Vaidman

The change of the electromagnetic field in a particular place due to the event of a change in the motion of a charged particle can occur only after the light signal from the event can reach this place. Naive calculations of the electromagnetic energy and the work performed by the electromagnetic fields might lead to paradoxes of apparent non-conservation of

A. A. Natale

We discuss the production of hadronic resonances in very peripheral heavy ion collisions, where the ions collide with impact parameter larger than twice the nuclear radius and remain intact after the collision. We compare the resonance production through two-photon and double Pomeron exchange, showing that when we impose the condition for a peripheral intera

Shadow J. Q. Robinson, Larry Zamick

We perform calculations for M1 transitions and allowed Gamow Teller (GT) transitions in the even-even Titanium isotopes - $^{44}$Ti, $^{46}$Ti, and $^{48}$Ti. We first do calculations with the FPD6 interaction. Then to study the effect of T=0 matrix elements on the M1 and GT rates we introduce a second interaction in which all the T=0 matrix elements are set

R. Fossion, C. De Coster, J. E. Garcia-Ramos, K. Heyde

We point out that the proton-neutron energy contribution, for low multipoles (in particular for the quadrupole component), effectively renormalizes the strength of the pairing interaction acting amongst identical nucleons filling up a single-j or a set of degenerate many-j shells. We carry out the calculation in lowest-order perturbation theory. We perform a

H. Sagawa, G. Colo, T. Suzuki

New structure problems are raised in nuclei near drip lines by recent RIB experiments. We pointed out the importance of dynamical effect beyond mean field theories to the new structure problems.

K. E. Gregorich, W. Loveland, A. Ghiorso, D. C. Hoffman

The published claim for the discovery of element 118 is retracted.

J. T. Mitchell, PHENIX Collaboration

The central arm spectrometers for the PHENIX experiment at the Relativistic Heavy Ion Collider have been designed for the optimization of particle identification in relativistic heavy ion collisions. The spectrometers present a challenging environment for event reconstruction due to a very high track multiplicity in a complicated, focusing, magnetic field. I

A. Mischke

In this paper we present recent results from the NA49 experiment for $Λ$ and $\barΛ$ hyperons produced in central Pb+Pb collisions at 40, 80 and 158 A$\cdot$GeV. Transverse mass spectra and rapidity distributions for $Λ$ are shown for all three energies. The shape of the rapidity distribution becomes flatter with increasing beam energy. The multiplicities at

Xin Wang, Shiyi Chen, Robert E. Ecke, Gregory L. Eyink

We study inertial-range statistics in the direct enstrophy cascade of two-dimensional turbulence via a numerical simulation of the forced Navier-Stokes equation. In particular, we obtain the distribution of the enstrophy flux and of the angle of alignment of the large-scale vorticity gradient with the small-scale vorticity transport vector. These distributio

P. Garcia, A. Parravano, M. G. Cosenza, J. Jimenez

Networks of chaotic coupled maps are considered as string and language generators. It is shown that such networks can be used as encrypting systems where the ciphertext contains information about the evolution of the network and also about the way to select the plaintext symbols from the string associated to the network evolution. The secret key provides the

Cristobal lopez, Davide Vergni, Angelo Vulpiani

We perform a numerical study of the reaction efficiency in a closed vessel. Starting with a little spot of product, we compute the time needed to complete the reaction in the container following an advection-reaction-diffusion process. Inside the vessel it is present a cellular velocity field that transports the reactants. If the size of the container is not

Clifford H. Taubes

This article provides some estimates for the relative sizes of the electric and magnetic contributions to the energy functional for the minimum energy configuration of an SU(2) gauge field on R^3 in the presence of an source in a fixed ball. The surprising fact is that the contribution to both energies from the free field region increases at worst linearly w

Andre Gsponer, Jean-Pierre Hurni

Many difficulties of interpretation met by contemporary researchers attempting to recast or generalize Dirac's, Proca's, or Maxwell's theories using biquaternions or Clifford numbers have been encountered long ago by a number of physicists including Lanczos, Proca, and Einstein. In the modern approach initiated by Gursey, these difficulties are s

Enrico De Micheli, Giacomo Monti Bragadin, Giovanni Alberto Viano

The geometrical diffraction theory, in the sense of Keller,is here reconsidered as an obstacle problem in the Riemannian geometry. The first result is the proof of the existence and the analysis of the main properties of the diffracted rays, which follow from the non-uniqueness of the Cauchy problem for geodesics in a Riemannian manifold with boundary. Then,

Shu-Ju Tu, Ephraim Fischbach

A formalism is presented for analytically obtaining the probability density function, (P_{n}(s)), for the random distance (s) between two random points in an (n)-dimensional spherical object of radius (R). Our formalism allows (P_{n}(s)) to be calculated for a spherical (n)-ball having an arbitrary volume density, and reproduces the well-known results for th

A. Zinger

We give a formula for the number of genus-two fixed-complex-structure degree-d plane curves passing through 3d-2 points in general position. This is achieved by completing Katz-Qin-Ruan's approach. This paper's formula agrees with the one obtained by the author in a completely different way.

Mao-Pei Tsui, Mu-Tao Wang

Let Σbe a complete minimal Lagrangian submanifold of \C^n. We identify regions in the Grassmannian of Lagrangian subspaces so that whenever the image of the Gauss map of Σlies in one of these regions, then Σis an affine space.

A. Chigogidze, A. Karasev, M. Rordam

It is proved that if X is a compact Hausdorff space of Lebesgue dimension $\dim(X)$, then the squaring mapping $α_{m} \colon (C(X)_{\mathrm{sa}})^{m} \to C(X)_{+}$, defined by $α_{m}(f_{1},..., f_{m}) = \sum_{i=1}^{m} f_{i}^{2}$, is open if and only if $m -1 \ge \dim(X)$. Hence the Lebesgue dimension of X can be detected from openness of the squaring maps $α

T. Constantinescu, J. L. Johnson

In this paper we continue to explore the connection between tensor algebras and displacement structure. We focus on recursive orthonormalization and we develop an analogue of the Szego type theory of orthogonal polynomials in the unit circle for several noncommuting variables. Thus, we obtain the recurrence equations and Christoffel-Darboux type formulas, as

Frank Quinn

The existence theorem for mapping cylinder neighborhoods is discussed as a prototypical example of controlled topology and its applications. The first of a projected series developed from lectures at the Summer School on High-Dimensional Topology, Trieste Italy 2001

Carlos Tomei, Tania Vieira

Given an m x n rectangular mesh, its adjacency matrix A, having only integer entries, may be interpreted as a map between vector spaces over an arbitrary field K. We describe the kernel of A: it is a direct sum of two natural subspaces whose dimensions are equal to $\lceil c/2 \rceil$ and $\lfloor c/2 \rfloor$, where c = gcd (m+1,n+1) - 1. We show that there

Deepak Parashar

We study the biparametric quantum deformation of GL(2) x GL(1) and exhibit its cross-product structure. We derive explictly the associated dual algebra, i.e., the quantised universal enveloping algebra employing the R-matrix procedure. This facilitates construction of a bicovariant differential calculus which is also shown to have a cross-product structure.

Peter A. Hasto

In this paper we present inequalities between two generalizations of the hyperbolic metric and the j_G metric. We also prove inequalities between generalized versions of the j_G metric and Seittenranta's metric.

Damir Filipovic, Josef Teichmann

In this paper we provide the characterization of all finite-dimensional Heath--Jarrow--Morton models that admit arbitrary initial yield curves. It is well known that affine term structure models with time-dependent coefficients (such as the Hull--White extension of the Vasicek short rate model) perfectly fit any initial term structure. We find that such affi

David Bachman

In this paper we introduce "critical surfaces", which are described via a 1-complex whose definition is reminiscent of the curve complex. Our main result is that if the minimal genus common stabilization of a pair of strongly irreducible Heegaard splittings of a 3-manifold is not critical, then the manifold contains an incompressible surface. Convers

Jerome Chabert, Siegfried Echterhoff, Ryszard Nest

Let $G$ be a locally compact group with cocompact connected component. We prove that the assembly map from the topological $\k$-theory of $G$ to the $\k$-theory of the reduced $C^*$-algebra of $G$ is an isomorphism.

Thomas Tradler

In this paper the Hochschild-cochain-complex of an A-infinity-algebra A with values in an A-infinity-bimodule M over A and maps between them is defined. Then, an infinity-inner-product on A is defined to be an A-infinity-bimodule-map between A and its dual A*. There is a graph-complex associated to A-infinity-algebras with infinity-inner-product.

Andrea Cappelli, Giuseppe D'Appollonio

We study the boundary states for the rational points in the moduli spaces of c=1 conformal and c=3/2 superconformal field theories, including the isolated Ginsparg points. We use the orbifold and simple-current techniques to relate the boundary states of different theories and to obtain symmetry-breaking, non-Cardy boundary states. We show some interesting e

G. Papadopoulos

Some selected applications of KT and HKT geometries in string theory, supergravity, black hole moduli spaces and hermitian geometry are reviewed. It is shown that the moduli spaces of a large class of five-dimensional supersymmetric black holes are HKT spaces. In hermitian geometry, it is shown that a compact, conformally balanced, strong KT manifold whose a

Wung-Hong Huang

The boundary string field theory approach is used to evaluate the one-loop tachyon potential. We first discuss the boundary condition at the two boundaries on annulus diagram and then the exact form of corrected potentials at zero and high temperature are obtained. The profile of the tachyon potential is found to be temperature independent and tachyon will c

Ilja Dorsner, S. M. Barr

In models with abelian flavor symmetry the small mixing angles and mass ratios of quarks and leptons are typically given by powers of small parameters characterizing the spontaneous breaking of flavor symmetry by "flavon" fields. If the scale of the breaking of flavor symmetry is near the weak scale, flavon exchange can lead to interesting flavor-vio

George Sterman

This talk reviews some recent trends in perturbative quantum chromodynamics, with emphasis on higher orders in perturbation theory, resummation and power corrections.

J. Berges

We calculate the far-from-equilibrium dynamics and thermalization both for the quantum and the classical O(N)--model. The early and late-time behavior can be described from the 2PI--loop expansion for weak couplings or the nonperturbative 2PI--1/N expansion of the effective action beyond leading order. A comparison with exact simulations in 1+1 dimensions in

Oliver Schwindt, Niels R. Walet

The finite-density and finite-temperature phase portraits of the baby-Skyrme and Skyrme models are investigated. Both grand-canonical and canonical approaches are employed. The grand-canonical approach can be used to find the ``natural'' crystal structure of the baby-Skyrme model and it is shown to have triangular symmetry. The phase portraits includ

Ashok Goyal, Meenu Dahiya, Deepak Chandra

We study chiral symmetry structure at finite density and temperature in the presence of external magnetic field and gravity, a situation relevant in the early Universe and in the core of compact stars. We then investigate the dynamical evolution of phase transition in the expanding early Universe and possible formation of quark nuggets and their survival.

H. Fritzsch

The progress of Particle Physics is closely linked to the progress in the understanding of the fundamental constants, like the finestructure constant, the mass of the electron or nucleon, or the electroweak mixing angle. The relation between the 18 fundamental constants of the Standard Model and the elementary units used in other fields like quantum optics o

V. Dzhunushaliev, D. Singleton

Within the context of the Abelian Projection of QCD monopole-like quantum excitations of gauge fields are studied. We start with certain classical solutions, of the SU(2) Yang-Mills field equations, which are not monopole-like and whose energy density diverges as $r \to \infty$. These divergent classical solutions are then quantized using a modified version

P. Bialas, A. Morel, B. Petersson, K. Petrov

Here we present a candidate for a Z(3)-symmetric reduced action for the description of the (2+1)D SU(3) gauge theory

Brigitte Vachon

Results from various searches for new physical phenomena performed by the four LEP experiments are summarised. Topics presented include the search for contact interactions, a Z' boson, leptoquarks, excited leptons, technicolour and gravity in extra dimensions.

G. Sardanashvily

A number of recent works in E-print arXiv have addressed the foundation of gauge gravitation theory again. As is well known, differential geometry of fibre bundles provides the adequate mathematical formulation of classical field theory, including gauge theory on principal bundles. Gauge gravitation theory is formulated on the natural bundles over a world ma

Victor Varela

We study Majumdar-Papapetrou solutions for the 3+1 Einstein-Maxwell equations, with charged dust acting as the external source for the fields. The spherically symmetric solution of Gürses is considered in detail. We introduce new parameters that simplify the construction of class $C^1$, singularity-free geometries. The arising sources are bounded or unbounde

Pierre-Louis Bazin, Mireille Boutin

We rephrase the problem of 3D reconstruction from images in terms of intersections of projections of orbits of custom built Lie groups actions. We then use an algorithmic method based on moving frames "a la Fels-Olver" to obtain a fundamental set of invariants of these groups actions. The invariants are used to define a set of equations to be solved

H. -A. Krug von Nidda, L. E. Svistov, M. V. Eremin, R. M. Eremina

We investigated the paramagnetic resonance in single crystals of LiCuVO$_4$ with special attention to the angular variation of the absorption spectrum. To explain the large resonance linewidth of the order of 1 kOe, we analyzed the anisotropic exchange interaction in the chains of edge-sharing CuO$_6$ octahedra, taking into account the ring-exchange geometry

M. H. Jung, N. Harrison, A. H. Lacerda, P. G. Pagliuso

We report measurements on single crystals of orthorhombic CeNiGe2, which is found to exhibit highly anisotropic magnetic and transport properties. The magnetization ratio M(H//b)/M(H^b) at 2 K is observed to be about 18 at 4 T and the electrical resistivity ratio r//b/r^b is about 70 at room temperature. It is confirmed that CeNiGe2 undergoes two-step antife

M. Kraemer, L. Pitaevskii, S. Stringari

The hydrodynamic equations of superfluids for a weakly interacting Bose gas are generalized to include the effects of periodic optical potentials produced by stationary laser beams. The new equations are characterized by a renormalized interaction coupling constant and by an effective mass accounting for the inertia of the system along the laser direction. F

Thomas Siller, Matthias Troyer, T. M. Rice, Steven R. White

Holes weakly doped into a four-leg \tj ladder bind in pairs. At dopings exceeding a critical doping of $δ_c\simeq {1/8}$ four hole clusters are observed to form in DMRG calculations. The symmetry of the ground state wavefunction does not change and we are able to reproduce this behavior qualitatively with an effective bosonic model in which the four-leg ladd

L. Salasnich, A. Parola, L. Reatto

Starting from the 3D Gross-Pitaevskii equation and using a variational approach, we derive an effective 1D wave-equation that describes the axial dynamics of a Bose condensate confined in an external potential with cylindrical symmetry. The trapping potential is harmonic in the transverse direction and generic in the axial one. Our equation, that is a time-d

Alex Kleiner

It is shown here that electrons on the surface of a nanotube in a perpendicular magnetic field undergo spin-chirality separation along the circumference. Stripes of spin-polarization propagate along the tube, with a spatial pattern that can be modulated by the electron filling.

I. L. Menezes-Sobrinho

In the present paper, a fiber bundle model in (1+1)-dimensions that simulates the rupture process of a fibrous material pulled by an uniaxial force F is analyzed. In this model the load of a broken fiber is shifted in equal portions onto the nearest unbroken fibers. The force-displacement diagram is obtained for several traction velocities v and temperatures

Sandro Sorella

We review a recent approach for the simulation of many-body interacting systems based on an efficient generalization of the Lanczos method for Quantum Monte Carlo simulations. This technique allows to perform systematic corrections to a given variational wavefunction, that allow to estimate exact energies and correlation functions, whenever the starting vari

A. Vernes, L. Szunyogh, P. Weinberger

We are reporting, for the first time in the literature, theoretical Kerr spectra of Co|Pt multilayer systems as obtained on a first principles basis including multiple reflections and interferences from all the boundaries in-between the layers.

A. Vernes, L. Szunyogh, P. Weinberger

Based on Luttinger's formulation the complex optical conductivity tensor is calculated within the framework of the spin-polarized relativistic screened Korringa-Kohn-Rostoker method for layered systems by means of a contour integration technique. For polar geometry and normal incidence ab-initio Kerr spectra of multilayer systems are then obtained by inc

A. Vernes, L. Szunyogh, L. Udvardi, P. Weinberger

The complex optical conductivity tensor is calculated for the Co|Pt systems by applying a contour integration technique within the framework of the spin-polarized relativistic screened Korringa-Kohn-Rostoker method. It is shown that the optical conductivity of the Co|Pt multilayer systems is dominated by contributions arising from the Pt cap and/or substrate

D P Foster, C Gerard

The critical properties of the mixed ferro/antiferromagnetic q-state Potts model on the square lattice are investigated using the numerical transfer matrix technique. The transition temperature is found to be substantially lower than previously found for q=3. It is conjectured that there is no transition for q>3, in contradiction with previous results.

M. B. Salamon, P. Lin, S. H. Chun

It is now widely accepted that the magnetic transition in doped manganites that show large magnetoresistance is a type of percolation effect. This paper demonstrates that the transition should be viewed in the context of the Griffiths phase that arises when disorder suppresses a magnetic transition. This approach explains unusual aspects of susceptibility an

T. Kontos, M. Aprili, J. Lesueur, F. Genet

We investigate Josephson coupling through a ferromagnetic thin film using Superconductor-Insulator-Ferromagnet-Superconductor planar junctions. Damped oscillations of the critical current are observed as a function of the ferromagnetic layer thickness. We show that they result from the exchange energy gained or lost by a quasiparticle Andreev-reflected at th

J. B. Majer, J. R. Butcher, J. E. Mooij

A phase-bias tool, based on a trapped fluxoid in a ring, is proposed and demonstrated. It can provide arbitrary phase values and is simple to fabricate. The phase bias has been realized in two superconducting quantum interference devices, where the critical current versus magnetic flux is shown to be shifted by a π/2 and π.

J. W. Quilty, S. Lee, A. Yamamoto, S. Tajima

Polarisation-resolved Raman scattering measurements were performed on MgB_2 single crystals to determine the magnitude, symmetry and temperature dependence of the superconducting gap. A single sharp peak due to Cooper pair breaking appears in the electronic continuum below Tc, reaching an average maximum Raman shift of 105 +/- 1 cm^{-1} (2 Delta(0) / k_{B}Tc

Daniel Cartin, Gaurav Khanna

Withdrawn; paper superceded by astro-ph/0105392

Simon Johnston, Roger W. Romani

We have carried out a survey for `giant pulses' in 6 young, Vela-like pulsars. In no cases did we find single pulses with flux densities more than 10 times the mean flux density. However, in PSR B1706-44 we have detected giant micro-pulses very similar to those seen in the Vela pulsar. In PSR B1706-44 these giant micro-pulses appear on the trailing edge

K. Hurley, T. Cline, I. Mitrofanov, E. Mazets

The 3rd Interplanetary Network (IPN) has been operating since April 2001 with two distant spacecraft, Ulysses and Mars Odyssey, and numerous near-Earth spacecraft, such as BeppoSAX, Wind, and HETE-II. Mars Odyssey is presently in orbit about Mars, and the network has detected approximately 30 cosmic, SGR, and solar bursts. We discuss the results obtained to

L. Cambresy, C. A. Beichman, T. H. Jarrett, R. M. Cutri

We propose a general method for mapping the extinction in dense molecular clouds using 2MASS near-infrared data. The technique is based on the simultaneous utilization of star counts and colors. These two techniques provide independent estimations of the extinction and each method reacts differently to foreground star contamination and to star clustering. We

Gerardo A. Vazquez, Leticia Carigi, J. J. Gonzalez

We have developed a new evolutionary synthesis code, which incorporates the output from chemical evolution models. We compare results of this new code with other published codes, and we apply it to the irregular galaxy NGC 1560 using sophisticated chemical evolution models. The code makes important contributions in two areas: a) the building of synthetic pop

David S. Rupke, Sylvain Veilleux, D. B. Sanders

In this paper, we present moderately-high resolution (~65 km/s) spectroscopy, acquired with ESI on Keck II, of 11 ultraluminous infrared galaxies at z < 0.3 from the IRAS 1 Jy sample. The targets were chosen as good candidates to host galaxy-scale outflows, and most have infrared luminosities dominated by star formation. We use a chi-squared minimization to

James E. Taylor, Arif Babul

We have developed a new semi-analytic model for the formation and evolution of structure on galaxy, group and cluster scales. The model combines merger trees with a detailed, spatially resolved description of the dynamical evolution of halo substructure. It reproduces the results of numerical simulations of mergers and halo formation at a fraction of the com

I. Bombaci

In this talk we discuss possible signatures for the existence of strange quark matter stars (strange stars).

L. Morales-Rueda, T. R. Marsh

Spiral shocks in cataclysmic variables (CVs) are the result of tidal interactions of the mass donor star with the accretion disc. Their study is fundamental for our understanding of angular momentum transfer in discs. In our quest to learn how widespread amongst binaries spiral shocks are, and how their presence depends upon orbital period and mass ratio (as

L. Morales-Rueda, T. R. Marsh

Up to now, only a very small number of dwarf novae have been studied during their outburst state (~30 per cent in the Northern hemisphere). In this paper we present the first comprehensive atlas of outburst spectra of dwarf novae. We study possible correlations between the emission and absorption lines seen in the spectra and some fundamental parameters of t

M. R. Pestalozzi, E. M. L. Humphreys, R. S. Booth

We report SIMBA 1.2 mm dust continuum observations of the environments of eight methanol maser sources, all discovered during spatially fully-sampled, untargeted surveys of the galactic plane. We summarise our search for possible associations of the masers with IR sources (IRAS and MSX) and find that it is not always possible to make definite associations. A

E. Daddi, A. Cimatti, T. Broadhurst, A. Renzini

We compare the 3D clustering of old passively-evolving and dusty star-forming z~1 EROs from the K20 survey. With detailed simulations of clustering, the comoving correlation length of dusty star-forming EROs is constrained to be less than r_0~2.5 Mpc/h. In contrast, the old EROs are much more positively correlated, with 5.5<~r_0/(Mpc/h)<~16, consistent with

Sofia Feltzing, Rachel Johnson

Using two epochs of HST/WFPC2 images of the metal-rich globular cluster NGC 6528 we derive the proper motions of the stars and use them to separate the stars belonging to NGC 6528 from those of the Galactic bulge. The stellar sequences in theresulting colour-magnitude diagram for the cluster are significantly better determined than in previously published da

J. W. Sulentic, P. Marziani, R. Zamanov, R. Bachev

[LaTeX removed] Recent work has shown that it is possible to systematize quasar spectral diversity in a parameter space called ``Eigenvector 1&#39;&#39; (E1). We present median AGN spectra for fixed regions of the E1 (optical) parameter space (FWHM(H-beta) vs. equivalent width ratio RFE=W(FeII4570)/W(H-beta). Comparison of the median spectra for different re

C. M. Gutierrez, M. Azzaro, F. Prada

We present the first results of an ongoing project to study the morphological, kinematical, dynamical, and chemical properties of satellite galaxies of external giant spiral galaxies. The sample of objects has been selected from the catalogue by Zaritsky et al. (1997). The paper analyzes the morphology and structural parameters of a subsample of 60 such obje

Anatoly Spitkovsky, Jonathan Arons

We present initial results of the first self-consistent numerical model of the outer magnetosphere of a pulsar. By using the relativistic ``particle-in-cell&#39;&#39; method with special boundary conditions to represent plasma dynamics in 3D, we are able to follow magnetospheric plasma through the light cylinder into the wind zone for arbitrary magnetic incl

T. Kato, K. Matsumoto, M. Uemura

V893 Sco is a recently rediscovered bright eclipsing dwarf nova below the period gap. Most recently, Mason et al. (2001) proposed an idea that V893 Sco is an ER UMa-type dwarf nova. From the analysis of our CCD observations and reports to VSNET, we show that V893 Sco bears no similar characters with ER UMa stars. We propose that the arguments in Mason et al.

Akio K. Inoue

We discuss the dust distribution within photoionized regions. Assuming a geometry with a central dust cavity, which is strongly suggested by the literature, we can estimate the cavity&#39;s radius from the ratio of the infrared and radio fluxes by using a simple transfer model of Lyman continuum photons. We apply the method to a sample of the Galactic H {\sc

Noam Soker

In this review I present the binary model for the shaping of planetary nebulae (PNe) as I view it, in the context of historical evolution of other models for the shaping of PNe over more than 30 years. In describing the binary model, I concentrate on works published since the last IAU meeting on PNe. I think stellar companions are behind the shaping of bipol

R. C. Berrington, P. M. Lugger, H. N. Cohn

We present 236 new radial velocities of galaxies in the cluster A2256 measured with the WIYN Hydra multi-object spectrograph. Combined with the previous work of Fabricant, Kent, and Kurtz (1989), we have velocities for a total of 319 galaxies of which 277 are cluster members. In addition to the new radial velocities, we present a 3x3 image mosaic in the R ba