February 1999 arXiv papers — page 15

Giuseppe Castagnoli

A typical oracle problem is finding which software program is installed on a computer, by running the computer and testing its input-output behaviour. The program is randomly chosen from a set of programs known to the problem solver. As well known, some oracle problems are solved more efficiently by using quantum algorithms; this naturally implies changing t

F. Benatti, R. Floreanini

We analyze the dynamics of neutron beams in interferometry experiments using quantum dynamical semigroups. We show that these experiments could provide stringent limits on the non-standard, dissipative terms appearing in the extended evolution equations.

K. M. D. Vant, G. H. Ball, H. Ammann, N. L. Christensen

We investigate the effect of cantori on momentum diffusion in a quantum system. Ultracold caesium atoms are subjected to a specifically designed periodically pulsed standing wave. A cantorus separates two chaotic regions of the classical phase space. Diffusion through the cantorus is classically predicted. Quantum diffusion is only significant when the class

Kirk T. McDonald

The case for a future high-energy collider based on muon beams is briefly reviewed.

Jacobus A. de Wet

We show in this note how many electron irreducible representations of the Lorentz group L can be expressed in terms of the sums of Slater determinants and principal minors. In this way the full configuration wave function of quantum chemistry is derived without any appeal to the Schrodinger equation and Born-Oppenheimer approximation. In particular the numbe

A. A. Galeev A. M. Sadovski

Axford and McKenzie [1992] suggested that the energy released in impulsive reconnection events generates high frequency Alfvén waves. The kinetic equation for spectral energy density of waves is derived in the random phase approximation. Solving this equation we find the wave spectrum with the power law ``-1'' in the low frequency range which is matc

Torsten Andersen

In order to study the possible phase conjugation of optical near-fields, it is necessary to go beyond the slowly varying envelope- and electric dipole approximations that are normally applied in phase conjugation studies where spatially non-decaying (or at least slowly decaying) modes are mixed. In the present dissertation, the minimal coupling Hamiltonian i

F. M. Nunes, I. J. Thompson

Following earlier one-step calculations, we explore the contributions of multi-step effects for the breakup of low energy $^8$B on $^{58}$Ni and $^{208}$Pb within a coupled discretised continuum channels (CDCC) formalism. The Coulomb multi-step differential cross section is significantly reduced for all angles, the largest effect being the destructive interf

D. S. Kulyabov, Yu. P. Rybakov, G. N. Shikin, L. P. Yuschenko

We have obtained exact kink-like static plane-symmetric solutions to the self-consistent system of electromagnetic, scalar, and gravitational field equations. It was shown that under certain choice of the interaction Lagrangian the solutions are regular and have localized energy. The linearized instability of corresponding solutions was established both for

Sylvain Poirier

This article is the continuation of our first article (math/9901028). It shows how the zero-anomaly result of Yang implies the equality between the configuration space integral and the Kontsevich integral.

Slawomir Cynk, Tomasz Szemberg

We study a class of Calabi-Yau varieties that can be represented as a non-singular model of a double covering of $\mathbb P^3$ branched along certain octic surfaces. We compute Euler numbers of all constructed examples and describe their resolution of singularities.

Maks A. Akivis, Vladislav V. Goldberg

The authors study the geometry of lightlike hypersurfaces on pseudo-Riemannian manifolds $(M, g)$ of Lorentzian signature. Such hypersurfaces are of interest in general relativity since they can be models of different types of physical horizons. For a lightlike hypersurface $V \subset (M, g)$ of general type and for some special lightlike hypersurfaces (name

Maks A. Akivis, Vladislav V. Goldberg

The authors study the geometry of lightlike hypersurfaces on manifolds $(M, c)$ endowed with a pseudoconformal structure $c = CO (n - 1, 1)$ of Lorentzian signature. Such hypersurfaces are of interest in general relativity since they can be models of different types of physical horizons. On a lightlike hypersurface, the authors consider the fibration of isot

Martin Goldstern, Saharon Shelah

1. For many regular cardinals lambda (in particular, for all successors of singular strong limit cardinals, and for all successors of singular omega-limits), for all n in {2,3,4, ...} : There is a linear order L such that L^n has no (incomparability-)antichain of cardinality lambda, while L^{n+1} has an antichain of cardinality lambda . 2. For any nondecreas

Sandrine Grellier, Philippe Jaming

In this paper, we pursue the study of harmonic functions on the real hyperbolic ball started by the second named author. Our focus here is on the theory of Hardy, Hardy-Sobolev and Lipschitz spaces of these functions. We prove here that these spaces admit Fefferman-Stein like characterizations in terms of maximal and square functionals. We further prove that

Philippe Jaming

We study harmonic functions for the Laplace-Beltrami operator on the real hyperbolic ball. We obtain necessary and sufficient conditions for this functions and their normal derivatives to have a boundary distribution.In doing so, we put forward different behaviors of hyperbolic harmonic functions according to the parity of the dimension of the hyperbolic bal

A. Chakrabarti

A particularly simple class of nonselfdual solutions are obtained for gauge fields in Schwarzschild and deSitter backgrounds. For Lorentz signature these have finite energy and finite action for Euclidean signature. In each case one obtains either real or a pair of complex conjugate solutions. The actions are easily computed for any dimension d. Numerical va

P. I. Fomin, T. Yu. Kuzmenko

In this paper we investigate a generation mechanism of the non-Abelian gauge fields in the SU(N) gauge theory. It is shown that the SU(N) gauge fields ensuring the local invariance of the theory are generated at the quantum level only due to nonsmoothness of the scalar phases of the fundamental spinor fields. The expression for the gauge fields are obtained

Tomohiro Matsuda

We examine the decoupling properties of the N=2 SQCD vacua when the adjoint mass term is turned on and then the N=1 limit is taken. The BPS domain wall tension in N=1 MQCD and SQCD is also examined. The correspondence of the MQCD integrals with the superpotential and the gaugino condensate is shown.

Thomas G. Rizzo

We review the effects of an anomalous chromomagnetic moment on top quark pair production at the Tevatron for Run II. Apart from an overall rescaling by the total cross section these couplings have little influence on top production characteristics. We then examine how the exchange of a Kaluza-Klein tower of gravitons arising from the low scale quantum gravit

S. Khlebnikov, I. Tkachev

We consider phase separation in nonequilibrium Bose gas with an attractive interaction between the particles. Using numerical integrations on a lattice, we show that the system evolves into a state that contains drops of Bose-Einstein condensate suspended in uncondensed gas. When the initial gas is sufficiently rarefied, the rate of formation of this quantum

G. Raffelt

Nonstandard neutrino properties (masses, mixing, sterile states, electromagnetic interactions, and so forth) can have far-reaching ramifications in astrophysics and cosmology. We look at the most interesting cases in the light of the powerful current indications for neutrino oscillations.

P. Osland, P. N. Pandita

Trilinear couplings of the neutral CP-even Higgs bosons in the Minimal Supersymmetric Standard Model (MSSM) can be measured through the multiple production of the lightest CP-even Higgs boson (h) at high-energy e^+e^- colliders. This includes the production of the heavier CP-even Higgs boson (H) via e^+e^- \to ZH, in association with the CP-odd Higgs boson (

Samina S. Masood, A. Perez Martinez, H. Perez Rojas, R. Gaitan

We compute the effective magnetic moment of neutrino in the highly dense and strongly magnetized media. It is shown that this magnetic moment is generated due to the effective mass of neutrino and gives sufficiently high value of the magnetic moment in the core of neutron stars.

G. L. Fogli, E. Lisi, A. Marrone, G. Scioscia

Neutrino decay has been proposed as a possible solution to the atmospheric neutrino anomaly, in the light of the recent data from the Super-Kamiokande experiment. We investigate this hypothesis by means of a quantitative analysis of the zenith angle distributions of neutrino events in Super-Kamiokande, including the latest (45 kTy) data. We find that the neu

Nicola Bianchi, Eric Thomas

A description of the virtual photon absorption cross section difference σ_{1/2}-σ_{3/2} for the proton and the neutron is obtained with a parameterisation based on a Regge type approach. The parameterisation is obtained from global fits to the cross section data derived from the spin asymmetries measured in DIS of longitudinally polarised leptons from polari

K. Gallmeister, B. Kaempfer, O. P. Pavlenko

We study the prospects to get information about the early and hot stages of deconfined matter produced in relativistic heavy-ion collisions by analyzing dilepton and single-lepton spectra. Energy losses of heavy quarks in deconfined matter and thermalization effects in hadron matter and their influence on lepton spectra are considered.

A. V. Berezhnoy, V. V. Kiselev, A. K. Likhoded

In the framework of the model motivated by perturbative calculations in the fourth $O(α^3_sα)$-order, the estimates for the $γp$ cross-section of the $D^*$-meson production in the ZEUS experiment are performed. We factorize the hadronization of $(c\bar q)$-state hardly produced in perturbative QCD, which allows us to take into account the higher twist terms

B. L. G. Bakker, A. I. Veselov, M. A. Zubkov

New topological objects, which we call center monopoles, naturally arise in the Maximal Center Projection of SU(3) gluodynamics. The condensate of the center monopoles is the order parameter of the theory.

Franck Chevalier, David Harle, Geoffrey Smith

Trilogy is a collaborative project whose key aim is the development of an integrated virtual laboratory to support research training within each institution and collaborative projects between the partners. In this paper, the architecture and underpinning platform of the system is described with particular emphasis being placed on the structure and the integr

Barry M. Leiner, Ekaterina A. Drozdova

The Cross-Industry Working Team (XIWT), with the support of the Stanford University Consortium for Research on Information Security and Policy (CRISP), sponsored a symposium on cross-industry activities aimed at improving the reliability, dependability, and robustness of the information infrastructure. Held 3-4 November 1998 in Crystal City, Virginia, the sy

Robert K. France, Lucy Terry Nowell, Edward A. Fox, Rani A. Saad

Digital libraries must reach out to users from all walks of life, serving information needs at all levels. To do this, they must attain high standards of usability over an extremely broad audience. This paper details the evolution of one important digital library component as it has grown in functionality and usefulness over several years of use by a live, u

Adam Smith, Anton Stiglic

We present here a generalization of the work done by Rabin and Ben-Or. We give a protocol for multiparty computation which tolerates any Q^2 active adversary structure based on the existence of a broadcast channel, secure communication between each pair of participants, and a monotone span program with multiplication tolerating the structure. The secrecy ach

A. R. Lima, J. S. Sá Martins, T. J. P. Penna

We apply the Broad Histogram Method to an Ising system in the context of the recently reformulated Generalized Thermostatistics, and we claim it to be a very efficient simulation tool for this non-extensive statistics. Results are obtained for the nearest-neighbour version of the Ising model for a range of values of the $q$ parameter of Generalized Thermosta

Eugene H. Kim, German Sierra, Daniel Duffy

We applied the Recurrent Variational Approach to the two-leg Hubbard ladder. At half-filling, our variational Ansatz was a generalization of the resonating valence bond state. At finite doping, hole pairs were allowed to move in the resonating valence bond background. The results obtained by the Recurrent Variational Approach were compared with results from

Brian R. La Cour, William C. Schieve

We consider the time dependent probability distribution of a coarse grained observable Y whose evolution is governed by a discrete time map. If the map is mixing, the time dependent one-step transition probabilities converge in the long time limit to yield an ergodic stochastic matrix. The stationary distribution of this matrix is identical to the asymptotic

P. T. Coleridge

An integer Quantum Hall effect transition is studied in a modulation doped p-SiGe sample. In contrast to most examples of such transitions the longitudinal and Hall conductivities at the critical point are close to 0.5 and 1.5 (e^2/h), the theoretically expected values. This allows the extraction of a scattering parameter, describing both conductivity compon

Rochus Klesse, Marcus Metzler

It is the purpose of the present article to show that so-called network models, originally designed to describe static properties of disordered electronic systems, can be easily generalized to quantum-{\em dynamical} models, which then allow for an investigation of dynamical and spectral aspects. This concept is exemplified by the Chalker-Coddington model fo

Paul N. Walker, Yuval Gefen, Gilles Montambaux

We analyse the ground state of spinless fermions on a lattice in a weakly disordered potential, interacting via a nearest neighbour interaction, by applying the self-consistent Hartree-Fock approximation. We find that charge density modulations emerge progressively when r_s >1, even away from half-filling, with only short-range density correlations. Classica

Suresh G. Mishra, P. A. Sreeram

Specific heat versus temperature curves for various pressures, or magnetic fields (or some other external control parameter) have been seen to cross at a point or in a very small range of temperatures in many correlated fermion systems. We show that this behavior is related to the vicinity of a quantum critical point in these systems which leads to a crossov

Sergey M. Apenko

A phenomenological criterion for the superfluid transition is proposed, which is similar to the Lindemann criterion for the crystal melting. Then we derive a new formula for the critical temperature, relating $T_λ$ to the mean kinetic energy per particle above the transition. The suppression of the critical temperature in a sufficiently dense liquid is descr

C. Manwart, R. Hilfer

A simulated annealing algorithm is applied to the reconstruction of two-dimensional porous media with prescribed correlation functions. The experimental correlation function of an isotropic sample of Fontainebleau sandstone and a synthetic correlation function with damped oscillations are used in the reconstructions. To reduce the numerical effort we follow

Seung-Pyo Hong, Sung-Ho Suck Salk

Focusing on the hole-doped two-dimensional systems of strongly correlated electrons, we examine geometric phases acquired by electronic wave functions as a result of polaron transport around a closed loop. For this study we apply the Lanczos exact diagonalization method to Holstein-Hubbard, Holstein-$tJ$, and Holstein-$tJ_z$ models in order to reveal various

Jinwu Ye

We study the consequences of random mass, random scalar potential and random vector potential on the line of clean fixed points between integer/fractional quantum Hall states and an insulator. This line of fixed points was first identified in a clean Dirac fermion system with both Chern-Simon coupling and Coulomb interaction in Phys. Rev. Lett. {\bf 80}, 540

Tom Schork, Stefan Blawid, Jun-ichi Igarashi

We investigate a Kondo lattice model with correlated conduction electrons. Within dynamical mean-field theory the model maps onto an impurity model where the host has to be determined self-consistently. This impurity model can be derived from an Anderson-Hubbard model both by equating the low-energy excitations of the impurity and by a canonical transformati

I. Knittel, F. Gagel, M. Schreiber

We study numerically the influence of momentum-conserving dephasing on the transport in a disordered chain of scatterers. Loss of phase memory is caused by coupling the transport channels to dephasing reservoirs. In contrast to previously used models, the dephasing reservoirs are linked to the transport channels between the scatterers, and momentum conservin

J. A. Munoz, E. E. Falco, C. S. Kochanek, J. Lehar

We describe the goals of the CASTLES (CfA-Arizona-Space-Telescope-LEns-Survey) project including a sample of NICMOS images of gravitational lenses and a brief list of the preliminary findings.

Dimitrios Psaltis, Tomaso Belloni, Michiel van der Klis

We study systematically the ~0.1-1200 Hz quasi-periodic oscillations (QPOs) and broad noise components observed in the power spectra of non-pulsing neutron-star and black-hole low-mass X-ray binaries. We show that among these components we can identify two, occurring over a wide range of source types and luminosities, whose frequencies follow a tight correla

Laurence P. David, William Forman, Christine Jones

We have compiled an X-ray catalog of optically selected rich clusters of galaxies observed by the PSPC during the pointed GO phase of the ROSAT mission. This paper contains a systematic X-ray analysis of 150 clusters with an optical richness classification of $R \geq 2$ from the ACO catalog (Abell, Corwin, and Olowin 1989). All clusters were observed within

Y. E. Lyubarskii, S. A. Petrova

We consider the polarization behaviour of radio waves propagating through an ultrarelativistic highly magnetized electron-positron plasma in a pulsar magnetosphere. The rotation of magnetosphere gives rise to the wave mode coupling in the polarization-limiting region. The process is shown to cause considerable circular polarization in the linearly polarized

Rashid Faizullin

The consideration of the N-body gravitational problem equations can give to us some class of boundary-value problems defined on the "beem's" construction. One can considere it as weak or so-called finite element method's approximation with the linear function's basis. So there are time and coordinate dependent beems as distances between p

C. R. Kerton, P. G. Martin

Studies of interstellar dust using the recently completed Mid-Infrared Galaxy Atlas (MIGA) and the soon to be launched Wide-Field Infrared Explorer (WIRE) satellite are summarized. Projects include looking at the distribution of dust around HII regions, the study of dust at the interfaces of HII regions and molecular clouds, and understanding the colour vari

F. Masset, M. Tagger

We present the results of two-dimensional numerical simulations of stellar galactic disks, aimed at studying the non-linear coupling between bar and spiral waves and modes, in disks with realistically peaked rotation profiles. The power spectrum analysis of the perturbed density in the disk, for azimuthal numbers ranging from m=0 to m=4, shows an unambiguous

M. L. Fil'chenkov

Torsion effects, including a spin precession in the torsion field, are considered. Some properties of neutrinos in cosmology are discussed. In the framework of Trautman's cosmological model with torsion estimated is a specific angular momentum of initial perturbations which proved to be of the order of the observable specific rotational moment for spiral

F. Masset, M. Tagger

We present a new mechanism to explain the frequently observed and thus certainly permanent warping of spiral galaxies. We consider the possibility of non-linear coupling between the spiral wave of the galaxy and two warp waves, such that the former, which is linearly unstable and extracts energy and angular momentum from the inner regions of the galactic dis

F. Masset, M. Tagger

We show that the propagation of warps in gaseous disks can be strongly affected by compressional effects, when the thickness of the disk is taken into account. The physical reason is that, in realistic self-gravitating disks, the sound time through the disk is comparable with the rotation time; thus the vertical hydrostatic equilibrium cannot be maintained a

Fred C. Adams, Manasse Mbonye, Gregory Laughlin

We explore possible effects of vacuum energy on the evolution of black holes. If the universe contains a cosmological constant, and if black holes can absorb energy from the vacuum, then black hole evaporation could be greatly suppressed. For the magnitude of the cosmological constant suggested by current observations, black holes larger than $\sim 4 \times

C. R. Kerton, P. G. Martin

A mid-infrared atlas of the Galactic Plane (MIGA) has been constructed to provide a mid-infrared data set for the Canadian Galactic Plane Survey, an international project to map all of the major components of the interstellar medium of the Milky Way at a common resolution of approximately 1'. The atlas is based on HIRES processing of IRAS 12 and 25 micro

C. R. Kerton, D. R. Ballantyne, P. G. Martin

Acquiring data for spectral classification of heavily reddened stars using traditional criteria in the blue-violet region of the spectrum can be prohibitively time consuming using small to medium sized telescopes. One such star is the Vatican Observatory emission-line star VES 735, which we have found excites the HII region KR140. In order to classify VES 73

K. Roettiger, J. O. Burns, J. M. Stone

We present a numerical model for the extended steep-spectrum radio sources and the elongated X-ray structure in A3667 based on new 3-dimensional MHD/N-body simulations. The X-ray and optical analyses of A3667 indicate that it has undergone a recent subcluster merger event. We believe that the Mpc-scale radio sources identified in A3667 are also a consequence

A. Richichi, R. Koehler, J. Woitas, Ch. Leinert

We report lunar occultation (LO) and speckle interferometry observations of Haro 6-37, all carried out at lambda=2.2 microns. The main finding is the discovery of a new close companion by LO, subsequently confirmed by speckle. The two techniques yield values in excellent agreement, with 0.331 arcseconds and 181 degrees for the separation and position angle r

K. -H. Kampert

The extensive air shower (EAS) experiment KASCADE has started data taking at the laboratory site of the Forschungszentrum Karlsruhe. The major goal is to determine the elemental composition of the primary cosmic ray particles in the energy range around and above the knee at $E_{\rm k} \approx 5 \cdot 10^{15}$ eV. Here, we shall discuss some results on tests

Andrew Gould, Samir Salim

Astrometric measurements of microlensing events can in principle determine both the "parallax" \tilde r_E and the "proper motion" μof an individual event which (combined with the Einstein time scale t_E) in turn yield the mass, distance, and transverse velocity of the lens. We show, however, that the parallax measurements are generically seve

Hector G. Arce, Alyssa A. Goodman

We present a study of the detailed distribution of extinction in a region of the Taurus dark cloud complex. Our study uses new BVR images of the region, spectral classification data for 95 stars, and IRAS Sky Survey Atlas (ISSA) 60 and 100 micron images. We study the extinction of the region in four different ways, and we present the first inter-comparison o

A. Morselli, A. Perrino, P. Picozza, S. Severoni

The gamma-ray detector AGILE, operating in the energy range from 30 MeV to 50 GeV, is composed by a tracking part, a light calorimeter and an anticoincidence system. Here we describe the detector and its capabilities to determine the arrival direction and energy of the detected photons.

Andrew W. Blain

A class of extremely luminous high-redshift galaxies has recently been detected in unbiased submillimetre-wave surveys using the Submillimetre Common-User Bolometer Array (SCUBA) camera at the James Clerk Maxwell Telescope. Most of the luminosity of these galaxies is emitted from warm interstellar dust grains, and they could be the high-redshift counterparts

Joseph A. Ball, Victor Vinnikov

This paper presents a new approach to constructing a meromorphic bundle map between flat vector bundles over a compact Riemann surface having a prescribed Weil divisor (i.e., having prescribed zeros and poles with directional as well as multiplicity information included in the vector case). This new formalism unifies the earlier approach of Ball-Clancey (in

Freddy P. Zen, Hendry I. Elim

The general multi-soliton solution of the integrable coupled nonlinear Schrodinger equation (NLS) of Manakov type is investigated by using Zakharov-Shabat (ZS) scheme. We get the bright and dark multi-soliton solution using inverse scattering method of ZS scheme. Elastic and inelastic collision of N-solitons solution of the equation are also discussed.

Peter Bouwknegt

We define the concept of an affinized projective variety and show how one can, in principle, obtain q-identities by different ways of computing the Hilbert series of such a variety. We carry out this program for projective varieties associated to quadratic monomial ideals. The resulting identities have applications in describing systems of quasi-particles co

Joannis Papavassiliou

For processes with gauge bosons in the final state we show how to continuously connect with a single Born-improved amplitude the resonant region, where resummation effects are important, with the asymptotic region far away from the resonance, where the amplitude must reduce to its tree-level form. While doing so all known field-theoretical constraints are re

Muneyuki Ishida

We recently observed the iso-singlet scalar sigma(600)-particle and the iso-doublet scalar kappa(900)-particle, through the re-analyses of pi pi- and K pi-scattering phase shifts, respectively. First, assuming the two iso-singlet states, the sigma(600) and the established f0(980), being the ideal mixing states n n and s s, respectively, of a single scalar no

Robert E. McGrath, Joe Futrelle, Ray Plante, Damien Guillaume

In this paper we describe our efforts to bring scientific data into the digital library. This has required extension of the standard WWW, and also the extension of metadata standards far beyond the Dublin Core. Our system demonstrates this technology for real scientific data from astronomy.

Raymond J. Mooney, Loriene Roy

Recommender systems improve access to relevant products and information by making personalized suggestions based on previous examples of a user's likes and dislikes. Most existing recommender systems use social filtering methods that base recommendations on other users' preferences. By contrast, content-based methods use information about an item its

Hector G. Arce, Alyssa A. Goodman

We test the recently published all-sky reddening map of Schlegel, Finkbeiner & Davis (1998 [SFD]) using the extinction study of a region in the Taurus dark cloud complex by Arce & Goodman (1999 [AG]). In their study, AG use four different techniques to measure the amount and structure of the extinction toward Taurus, and all four techniques agree very well.

Alvio Renzini

Insight into the origin of bulges is saught in this review only from the properties of their stellar populations. Evidence concerning the age of the Galactic bulge stellar population is reviewed first, then the case of the bulge of M31 is discussed. The similarity of bulges and ellipticals is then illustrated, inferring that the problems of the origin of bul

P. Bozek

We present a method to calculate nuclear matter properties in the superfluid phase. The method is based on the use of self-consistent off-shell nucleon propagators in the T-matrix equation. Such a complete treatment of the spectral function, is required below and around $T_c$ due to a pseudogap formation in the spectral function. In the superfluid phase we i

Tetsuya Shiromizu

We define gravitational mass in asymptotically de Sitter space-times with compactified dimension. It was shown that the mass can be negative for space-time with matter spreading beyond the cosmological horizon scale or large outward `momentum' in four dimension. We give simple examples with negative energy in higher dimensions even if the matter is not b

P. J. Arias, A. Khoudeir

A gauge invariant formulation for the massive axion is considered. The axion acquires mass through a topological term which couples a (pseudo)scalar and a third rank antisymmetric tensor. Duality, local and canonical equivalences with the non-gauge invariant proposal are established. The supersymmetric version of the gauge invariant model is constructed.

G. De Zotti, L. Toffolatti, F. Argüeso, R. D. Davies

Although the Planck Surveyor mission is optimized to map the cosmic microwave background anisotropies, it will also provide extremely valuable information on astrophysical phenomena. We review our present understanding of Galactic and extragalactic foregrounds relevant to the mission and discuss on one side, Planck's impact on the study of their properties a

Marco Buiatti, Paolo Grigolini, Luigi Palatella

Symbolic sequences with long-range correlations are expected to result in a slow regression to a steady state of entropy increase. However, we prove that also in this case a fast transition to a constant rate of entropy increase can be obtained, provided that the extensive entropy of Tsallis with entropic index q is adopted, thereby resulting in a new form o

S. Hino, S. Kumano

We analyze the polarized Drell-Yan processes with spin-1/2 and spin-1 hadrons in a parton model. Quark and antiquark correlation functions are expressed in terms of possible combinations of Lorentz vectors and pseudovectors with the constrains of Hermiticity, parity conservation, and time-reversal invariance. Then, we find tensor polarized distributions for

Oskar Pelc, Ruud Siebelink

The system of D2 branes localized on or near D6 branes is considered. The world-volume theory on the D2 branes is investigated, using its conjectured relation to the near-horizon geometry. The results are in agreement with known facts and expectations for the corresponding field theory and a rich phase structure is obtained as a function of the energy scale

L. A. Dickey

The discrete KP, or 1-Toda lattice hierarchy is the same as a properly defined modified KP hierarchy.

Ilki Kim, Guenter Mahler

We investigate an all-quantum-mechanical spin network, in which a subset of spins, the $K$ ``moving agents'', are subject to local and pair unitary transformations controlled by their position with respect to a fixed ring of $M$ ``environmental''-spins. We demonstrate that a ``flow of coherence'' results between the various subsystems

Guenter Mahler, Ilki Kim

We study a special inhomogeneous quantum network consisting of a ring of $M$ pseudo-spins (here $M = 4$) sequentially coupled to one and the same central spin under the influence of given pulse sequences (quantum gate operations). This architecture could be visualized as a quantum Turing machine with a cyclic ``tape''. Rather than input-output-relati

Bijoy Kundu, B. K. Jain

The formalism developed by Jain and Kundu for the propagation of a resonance in the nuclear medium has been modified to the case of heavy-ion collisions at relativistic energies. The formalism includes coherently the contribution to the observed di-lepton production from the decay of the resonance inside as well as outside the nuclear medium. The calculated

H. Sharda, R. K. Bansal, Ashwani Kumar

The present study concentrates on the average effective two-body interaction matrix elements being extracted, using sum-rule techniques, from transfer reactions on target states having single orbital as well as two orbitaloccupancy. This investigation deals with transfer reactions on f-p shell nuclei involving (i) $1f_{7/2}$ and $2p_{3/2}$ transfer on target

Bin Zhang, Miklos Gyulassy, Che Ming Ko

The dependence of elliptic flow at RHIC energies on the effective parton scattering cross section is calculated using the ZPC parton cascade model. We show that the v_2 measure of elliptic flow saturates early in the evolution before the hadronization transition to a rather large value ~0.05-0.15 as σ_g varies from 2-10 mb and thus is a sensitive probe of th

Ralph Grieder

Let $G$ be a finite group. To every smooth $G$-action on a compact, connected and oriented Riemann surface we can associate its data of singular orbits. The set of such data becomes an Abelian group $B_G$ under the $G$-equivariant connected sum. The map which sends $G$ to $B_G$ is functorial and carries many features of the representation theory of finite gr

Bernard de Wit

We review recent developments in the theory of supermembranes and their relation to matrix models.

Geoffrey Dixon

A derivation of the standard symmetry and leptoquark family structure is presented that is more straightforward than a previous derivation.

Stefano Kovacs

The finiteness properties of the N=4 supersymmetric Yang-Mills theory are reanalyzed both in the component formulation and using N=1 superfields, in order to discuss some subtleties that emerge in the computation of gauge dependent quantities. The one-loop corrections to various Green functions of elementary fields are calculated. In the component formulatio

Spencer Klein, Joakim Nystrand

Exclusive vector meson production reactions such as $Au + Au \to Au + Au + V$, where $V=ρ, ω, ϕ$ or $J/ψ$ can proceed through photon-Pomeron and photon-meson interactions. Photons from the electromagnetic field of one nucleus interact coherently with the other nucleus. Photonuclear cross sections are scaled from $γp$ data, and convoluted with the photon spec

CALEIDO collaboration, A. C. Benvenuti, I. Britvich, T. Camporesi

A novel technique for longitudinal segmentation of shashlik calorimeters has been tested in the CERN West Area beam facility. A 25 tower very fine samplings e.m. calorimeter has been built with vacuum photodiodes inserted in the first 8 radiation lengths to sample the initial development of the shower. Results concerning energy resolution, impact point recon

Hiroshi Kohno, Hidetoshi Fukuyama, Manfred Sigrist

Motivated by the observation of unusual magnetism in Ce_xCu_2Si_2 ($x\sim 1$), we study the effect of disorder, such as Ce vacancy, on the competition between superconductivity (SC) and antiferromagnetism (AF) on the basis of the phenomenological Ginzburg-Landau theory. Assuming that the AF-SC transition is of first order in clean system, we show that a sing

Unjong Yu, Yu. V. Skrypnyk, B. I. Min

Giant oxygen isotope effects observed in colossal magnetoresistance manganites are investigated by employing the combined model of the double exchange and interacting lattice polaron mechanism. We have shown that the isotope effects on $ T_C$ in the metallic phase and $ T_{CO}$ in the charge ordered phase of manganites can be explained well in terms of the d

Daniela Calzetti

The high-redshift (z>2) galaxies discovered over the last few years with the Lyman-break technique represent, in number density, a major fraction of the galaxies known in the Local Universe. Thus, understanding the properties and the nature of these high-redshift systems is instrumental to our understanding of the cosmic evolution of galaxies and their stell

G. C. McLaughlin, J. M. Fetter, A. B. Balantekin, G. M. Fuller

We discuss how matter-enhanced active-sterile neutrino transformation in both neutrino and antineutrino channels could enable the production of the rapid neutron capture (r-process) nuclei in neutrino-heated supernova ejecta. In this scheme the lightest sterile neutrino would be heavier than the electron neutrino and split from it by a vacuum mass-squared di

K. Roettiger, J. M. Stone, J. O. Burns

We present initial results from the first 3-dimensional numerical magnetohydrodynamical (MHD) simulations of magnetic field evolution in merging clusters of galaxies. Within the framework of idealized initial conditions similar to our previous work, we look at the gasdynamics and the magnetic field evolution during a major merger event in order to examine th

Mirt Gramann, Ivan Suhhonenko

We examine the power spectrum of clusters in the Press-Schechter (PS) theory and in N-body simulations to see how the power spectrum of clusters is related to the power spectrum of matter density fluctuations in the Universe. An analytic model for the power spectrum of clusters for their given number density is presented, both for real space and redshift spa