June 1999 arXiv papers — page 8

R. Shibata, H. Honda, M. Ishida, T. Ohashi

Abell 115 exhibits two distinct peaks in the surface brightness distribution. ASCA observation shows a significant temperature variation in this cluster, confirmed by a hardness ratio analysis and spectral fits. A linking region between main and sub clusters shows a high temperature compared with other regions. Two possibilities are examined as the cause of

John P. Blakeslee

Deep imaging data from the Keck II telescope are employed to study the globular cluster (GC) populations in the cores of six rich Abell clusters. The sample includes A754, A1644, A2124, A2147, A2151, and A2152, and spans the redshift range z = 0.035-0.066. The clusters also range in morphology from spiral-rich, irregular systems to centrally concentrated cD

Jonathan C. Tan

We invoke star formation triggered by cloud-cloud collisions to explain global star formation rates of disk galaxies and circumnuclear starbursts. Previous theories based on the growth rate of gravitational perturbations ignore the dynamically important presence of magnetic fields. Theories based on triggering by spiral density waves fail to explain star for

Randall D. Kamien

We formulate the dynamical theory of nematic polymers, starting from a microscopic Poisson bracket approach. We find that the Poisson bracket between the nematic director and momentum depends on the (Maier-Saupe) order parameter of the nematic phase. We use this to derive reactive couplings of the nematic director to the strain rates. Additionally, we find t

Eric S. Perlman, Greg Madejski, John T. Stocke, Travis A. Rector

We report on monitoring of the BL Lac object PKS 2005-489 by the Rossi X-ray Timing Explorer (RXTE) in October-December 1998. During these months, the source underwent a spectacular flare; at its peak on November 10, its 2-10 keV flux was $3.33 \times 10^{-10} {\rm ~erg ~cm^{-2} ~s^{-1}}$, over 30 times brighter than in quiescence. During the rising phase, t

C. Giunti

We present a simple scheme of mixing of four neutrinos that can accommodate the results of all neutrino oscillation experiments, the observed abundances of primordial elements and the current upper bound for the effective Majorana neutrino mass in neutrinoless double-beta decay (assuming that massive neutrinos are Majorana particles). The scheme has maximal

2 Collaboration

About 300 000 $e^+e^-\to ϕ\to K^0_L K^0_S$ events in the center of mass energy range from 984 to 1040 MeV were used for the measurement of the $ϕ$ meson parameters. The following results have been obtained: $σ_0 = (1367 \pm 15 \pm 21) nb, m_ϕ=(1019.504 \pm 0.011 \pm 0.033) MeV/c^2, Γ_ϕ=(4.477 \pm 0.036 \pm 0.022) MeV, Γ_{e^+e^-}\cdot B(ϕ\to K^0_L K^0_S) = (4

M. Letz, R. Schilling, A. Latz

For hard ellipsoids of revolution we calculate the phase diagram for the idealized glass transition. Our equations cover the glass physics in the full phase space, for all packing fractions and all aspect ratios X$_0$. With increasing aspect ratio we find the idealized glass transition to become primarily be driven by orientational degrees of freedom. For ne

H. Lu, C. N. Pope

We obtain the explicit and complete bosonic non-linear Kaluza-Klein ansatz for the consistent S^4 reduction of D=11 supergravity to N=1, D=7 gauged supergravity. This provides a geometrical interpretation of the lower dimensional solutions from the eleven-dimensional point of view.

Adrian Kent

The most dramatic developments in theoretical physics in the next millennium are likely to come when we make progress on so far unresolved foundational questions. In this essay I consider two of the deepest problems confronting us, the measurement problem in quantum theory and the problem of relating consciousness to the rest of physics. I survey some recent

U. Leonhardt, P. Piwnicki

A moving dielectric appears to light as an effective gravitational field. At low flow velocities the dielectric acts on light in the same way as a magnetic field acts on a charged matter wave. We develop in detail the geometrical optics of moving dispersionless media. We derive a Hamiltonian and a Lagrangian to describe ray propagation. We elucidate how the

U. Leonhardt, P. Piwnicki

A moving dielectric medium acts as an effective gravitational field on light. One can use media with extremely low group velocities [Lene Vestergaard Hau et al., Nature 397, 594 (1999)] to create dielectric analogs of astronomical effects on Earth. In particular, a vortex flow imprints a long-ranging topological effect on incident light and can behave like a

F. Lefloch, D. Quirion, M. Sanquer

We have measured the very low temperature (down to 30 mK) subgap resistance of Titanium Nitride (Superconductor, Tc = 4.6 K)/highly doped Silicon (Semiconductor) SIN junction (the insulating layer stands for the Schottky barrier). As the temperature is lowered, the resistance increases as expected in SIN junction. Around 300 mK, the resistance shows a maximu

Giampiero Esposito

Recent work in the literature has proposed the use of non-local boundary conditions in Euclidean quantum gravity. The present paper studies first a more general form of such a scheme for bosonic gauge theories, by adding to the boundary operator for mixed boundary conditions of local nature a two-by-two matrix of pseudo-differential operators with pseudo-hom

Soon-Tae Hong, Won Tae Kim, Young-Jai Park

In the framework of Dirac quantization with second class constraints, a free particle moving on the surface of a $(d-1)-$dimensional sphere has an ambiguity in the energy spectrum due to the arbitrary shift of canonical momenta. We explicitly show that this spectrum obtained by the Dirac method can be consistent with the result of the Batalin-Fradkin-Tyutin

O. Golinelli

We study the statistics of meanders, i.e. configurations of a road crossing a river through "n" bridges, and possibly winding around the source, as a toy model for compact folding of polymers. We introduce a Monte-Carlo method which allows us to simulate large meanders up to n = 400. By performing large "n" extrapolations, we give asymptotic

Armin Dertinger, Andreas Kreyssig, Clemens Ritter, Michael Loewenhaupt

We investigated the low-temperature properties of polycrystalline HoNi_2^11B_2C by means of ac-susceptibility and neutron powder diffraction in the temperature range of 1.5 to 10 K and zero magnetic field. A sample with pronounced re-entrant behaviour was chosen since it exhibits a superconducting state which is strongly affected by the intrinsic magnetism,

Naoki Itoh, Tsuyoshi Sakamoto, Shugo Kusano, Satoshi Nozawa

We present accurate analytic fitting formulae which summarize the results of the recent calculation by Nozawa, Itoh and Kohyama on the relativistic thermal bremsstrahlung Gaunt factor for the intracluster plasma. The fitting is carried out for Z = 1 to 28, 6.0 < log T < 8.5, -4.0 < log (omega/kT) < 1.0, where Z is the charge number of the ion, T is the tempe

Masayasu Harada, Koichi Yamawaki

It is observed that the Hidden Local Symmetry (HLS) for the vector mesons in the ordinary QCD with smaller N_f plays the role of the &#34;Higgsed magnetic gauge symmetry&#34; for the Seiberg duality in the SUSY QCD. For large N_f where the conformal phase transition with chiral restoration and deconfinement is expected to take place, we find that the HLS mod

H. Geiger, G. Obermair, Ch. Helm

The classical behaviour of a macroscopic system consisting of a large number of microscopic systems is derived in the framework of the Bohmian interpretation of quantum mechanics. Under appropriate assumptions concerning the localization and factorization of the wavefunction it is shown explicitly that the center of mass motion of the system is determined by

Dipankar Home, Rajagopal Chattopadhayaya

The biochemical attachment of photolyase to ultraviolet (uv) absorbed DNA molecules provides a method for registering whether a source has emitted photons. Here using laws of chemical kinetics and related experimental methods we argue that the instant after which this information becomes discernible can be empirically determined by retrodicting from relevant

Sohrab Rahvar

It is proposed that shock wave dynamics within the gas of a small bubble explain sonoluminescence, the emission of visible radiation. As the bubble radius oscillates, shock waves develop from spherical sound waves created inside the gas bubble. As any such shock propagates toward the center, it strengthens and, upon convergence and subsequent reflection, tem

J. Cleymans, K. Redlich

It is shown that the chemical freeze-out parameters obtained at CERN/SPS, BNL/AGS and GSI/SIS energies all correspond to a unique value of 1 GeV for the average energy per hadron.

V. Yu. Grishina, L. A. Kondratyuk, M. Büscher

We investigate the reactions p n -> d omega and p n -> d phi close to the corresponding thresholds. The S-wave amplitudes are calculated within the framework of the two-step model which is described by a triangle graph with pi, rho and omega mesons in the intermediate state. The cross sections of the reactions p n -> d omega and p n -> d phi are predicted to

S. L. Cherkas

It is shown that particle spin rotation in nuclear target, caused by the imaginary part of the spin-dependent forward scattering amplitude, is T-odd rotation.

D. Guido, R. Longo, J. E. Roberts, R. Verch

The first part of this paper extends the Doplicher-Haag-Roberts theory of superselection sectors to quantum field theory on arbitrary globally hyperbolic spacetimes. The statistics of a superselection sector may be defined as in flat spacetime and each charge has a conjugate charge when the spacetime possesses non-compact Cauchy surfaces. In this case, the f

G. Date

At the classical level anyons with harmonic confinement are known to exhibit two important properties namely partial separability and pseudo-integrability. These stem from the fact that this system is locally identical to isotropic oscillator system but differs in the global topology of the phase space. We clarify the meaning of pseudo-integrability and show

Bin Zhang

Equivariant Riemann-Roch theorem for the complex variety under the action of complex linear reductive algebraic group.

Alex Clark

The space of non-singular flows on any given solenoid is shown to contain a generic subset consisting of flows that are not almost periodic. Whether this result carries over to Hamiltonian flows remains an open question.

Sabir M. Gusein-Zade, Nikolay N. Nekhoroshev

Let $k(d)$ be the maximal possible integer $k$ such that there exists a plane curve of degree $d$ with an $A_k$--singularity. We construct a plane curve of degree $28s+9$ ($s\in\Z_{\ge 0}$) which has an $A_k$--singularity with $k=420s^2+269s+42$. Therefore one has $\underline{\lim}_{d\to\infty}k(d)/d^2\ge 15/28$ (pay attention that $15/28>1/2$).

Anatoliy K. Prykarpatsky

There is studied an invariant measure structure of a class of ergodicl discrete dynamical systems by means of the measure generating function method

P. Akueson, D. Gurevich

A new approach is suggested to quantum differential calculus on certain quantum varieties. It consists in replacing quantum de Rham complexes with differentials satisfying Leibniz rule by those which are in a sense close to Koszul complexes from \cite{G1}. We also introduce the tangent space on a quantum hyperboloid equipped with an action on the quantum fun

Shigetaka Fukuda

We prove that every log crepant birational morphism between log terminal surfaces is decomposed into log-flopping type divisorial contraction morphisms and log blow-downs. Repeating these two kinds of contractions we reach a minimal log minimal surface from any log minimal surface.

A. V. Isaev, S. G. Krantz

We show that there does not exist a Kobayashi hyperbolic complex manifold of dimension $n\ne 3$, whose group of holomorphic automorphisms has dimension $n^2+1$ and that, if a 3-dimensional connected hyperbolic complex manifold has automorphism group of dimension 10, then it is holomorphically equivalent to the Siegel space. These results complement earlier t

C. R. Hagen

It has recently been claimed that the inclusion of a Pauli term in (2+1) dimensions gives rise to a new type of anomalous spin term. The form of that term is shown to contradict the structure relations for the inhomogeneous Lorentz group.

Vasilios Zarikas

A derivative expansion technique is developed to compute functional determinants of quadratic operators, non diagonal in spacetime indices. This kind of operators arise in general &#39;t Hooft gauge fixed Lagrangians. Elaborate applications of the developed derivative expansion are presented.

L. C. de Albuquerque, M. Gomes, A. J. da Silva

We consider the scattering of relativistic electrons from a thin magnetic flux tube and perturbatively calculate the order $α$, radiative correction, to the first order Born approximation. We show also that the second order Born amplitude vanishes, and obtain a finite inclusive cross section for the one-body scattering which incorporates soft photon bremsstr

Elena Perazzi

We present the results of a general analysis of the contributions of the supersymmetry-breaking sector to the muon anomalous magnetic moment in models with a superlight gravitino. We find constraints on the model parameters that are comparable and complementary to the ones coming from collider searches, and will become more stringent after the Brookhaven E82

L. S. Kisslinger, M. Aw, A. Harey, O. Linsuain

The Schwinger-Dyson formalism is used to check the consistency of instanton model solutions for the quark propagator with recent models of confining gluon propagators. We find that the models are not consistent. A major discrepancy is the absence of a vector condensate in the instanton model that is present in the solutions with nonperturbative confining glu

J. Soffer, O. V. Teryaev

The positivity bound for the transverse asymmetry $A_2$ may be improved by making use of the fact, that the state of a photon and a nucleon with total spin 3/2, does not participate to the interference. The bound is therefore useful in the case of a longitudinal asymmetry small (say, at low $x$) or negative (like in the neuteron case).

D. L. Khokhlov

Structure of leptons and hadrons within the framework of electrodynamics is considered. Muon and tau-lepton have the structure of 3 electrons. The mass of muon is defined by the section of two-photon annihilation. The mass of tau-lepton is defined by the section of three-photon annihilation. Hadrons are characterized by the structure of 5 electrons. The mass

Kari Enqvist, Kimmo Kainulainen, Antti Sorri

We consider numerically the growth of neutrino asymmetry in active-sterile neutrino oscillations in the early universe. It is shown that the final sign of the asymmetry can be highly sensitive to small variations of the oscillation parameters. We find regions which are completely or partially chaotic, but also regions where the sign remains very robust. The

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

The evidence for $ν_μ$ disappearance in the Super-Kamiokande atmospheric neutrino experiment and the negative searches for $ν_e$ disappearance in the CHOOZ reactor experiment can be easily reconciled by assuming oscillations with large amplitude in the $ν_μ\leftrightarrowν_τ$ channel and small (or null) amplitude in the $ν_μ\leftrightarrowν_e$ channel. It ha

J. Marteau, J. Delorme, M. Ericson

The apparent anomaly in the ratio of muon to electron atmospheric neutrinos first observed by Kamiokande and IMB has been confirmed by Super-Kamiokande and Soudan-2. The experimental analysis, including the asymmetry in the zenithal distributions of the $ μ-\mathrm{type} $ events in Super-Kamiokande gives a strong support to the neutrino oscillation hypothes

A. V. Anisovich, V. V. Anisovich

We calculate the $00^{++}$-wave two-meson spectra for the reactions $γγ\toπ^0π^0$, $γγ\toπ^+π^-$, $γγ\to K^0\bar K^0$ and $γγ\to K^+ K^-$ on the basis of: (i) the results of the $K$-matrix analysis of the $00^{++}$ amplitudes for the reactions $ππ\to ππ$, $K\bar K$, $ηη$, $ηη&#39;$, $ππππ$, and (ii) recently developed method for calculation of the decay ampl

Palash B. Pal

I start by defining the cosmological parameters $H_0, Ω_m$ and $Ω_Λ$. Then I show how the age of the universe depends on them, followed by the evolution of the scale parameter of the universe for various values of the density parameters. Then I define strategies for measuring them, and show the results for the recent determination of these parameters from me

Yasuhiro Okada, Ken-ichi Okumura, Yasuhiro Shimizu

$μ^{+} \to e^{+} γ$ and $μ^{+} \to e^{+}e^{+}e^{-}$ processes are analyzed in detail with polarized muons in supersymmetric grand unified theories. We first present Dalitz plot distribution for $μ^{+} \to e^{+}e^{+}e^{-}$ decay based on effective Lagrangian with general lepton-flavor-violating couplings and define various P- and T-odd asymmetries. We calcula

S. Chandrasekharan, J. Cox, K. Holland, U. -J. Wiese

We examine a (3+1)-dimensional model of staggered lattice fermions with a four-fermion interaction and Z(2) chiral symmetry using the Hamiltonian formulation. This model cannot be simulated with standard fermion algorithms because those suffer from a very severe sign problem. We use a new fermion simulation technique - the meron-cluster algorithm - which sol

Othmar Brodbeck, Markus Heusler, Olivier Sarbach

It is shown that the dynamical evolution of perturbations on a static spacetime is governed by a standard pulsation equation for the extrinsic curvature tensor. The centerpiece of the pulsation equation is a wave operator whose spatial part is manifestly self-adjoint. In contrast to metric formulations, the curvature-based approach to gravitational perturbat

Brendan S. Guilfoyle

Static solutions of the electro-gravitational field equations exhibiting a functional relationship between the electric and gravitational potentials are studied. General results for these metrics are presented which extend previous work of Majumdar. In particular, it is shown that for any solution of the field equations exhibiting such a Weyl-type relationsh

Joseph O&#39;Rourke

The subquadratic algorithm of Kapoor for finding shortest paths on a polyhedron is described.

Joseph O&#39;Rourke, Irena Pashchenko

Everett et al. introduced several varieties of stabbing information for the lines determined by pairs of vertices of a simple polygon P, and established their relationships to vertex visibility and other combinatorial data. In the same spirit, we define the ``zero-parity (ZP) stabbing information&#39;&#39; to be a natural weakening of their ``weak stabbing i

Christoph Durr, Marek Chrobak

Tomography is the area of reconstructing objects from projections. Here we wish to reconstruct a set of cells in a two dimensional grid, given the number of cells in every row and column. The set is required to be an hv-convex polyomino, that is all its cells must be connected and the cells in every row and column must be consecutive. A simple, polynomial al

I. Androutsopoulos

Previous work in the context of natural language querying of temporal databases has established a method to map automatically from a large subset of English time-related questions to suitable expressions of a temporal logic-like language, called TOP. An algorithm to translate from TOP to the TSQL2 temporal database language has also been defined. This paper

Michel Rigo

Let L be an infinite regular language on a totally ordered alphabet (A,<). Feeding a finite deterministic automaton (with output) with the words of L enumerated lexicographically with respect to < leads to an infinite sequence over the output alphabet of the automaton. This process generalizes the concept of k-automatic sequence for abstract numeration syste

Massimo Rontani, F. Rossi, F. Manghi, E. Molinari

We study coupled semiconductor quantum dots theoretically through a generalized Hubbard approach, where intra- and inter-dot Coulomb Correlation, as well as tunneling effects are described on the basis of realistic electron wavefunctions. We find that the ground-state configuration of vertically-coupled double dots undergoes non-trivial quantum transitions a

S. A. Cannas, A. C. N. de Magalhaes, F. A. Tamarit

The q-state Potts model with long-range interactions that decay as 1/r^alpha subjected to an uniform magnetic field on d-dimensional lattices is analized for different values of q in the nonextensive regime (alpha between 0 and d). We also consider the two dimensional antiferromagnetic Ising model with the same type of interactions. The mean field solution a

G. Goldoni, F. Rossi, A. Orlandi, M. Rontani

We present a theoretical analysis of the effect of dielectric confinement on the Coulomb interaction in dielectrically modulated quantum structures. We discuss the implications of the strong enhancement of the electron-hole and electron-electron coupling for two specific examples: (i) GaAs-based quantum wires with remote oxide barriers, where combined quantu

R. Cafiero, P. De Los Rios, A. Valleriani, J. L. Vega

We study a random neighbor version of the Bak-Sneppen model, where &#34;nearest neighbors&#34; are chosen according to a probability distribution decaying as a power-law of the distance from the active site, P(x) \sim |x-x_{ac }|^{-ω}. All the exponents characterizing the self-organized critical state of this model depend on the exponent ω. As ωtends to 1 we

J. C. Campuzano, H. Ding, M. R. Norman, H. M. Fretwell

Photoemission spectra of Bi2Sr2CaCu2O8 reveal that the high energy feature near (pi,0), the &#34;hump&#34;, scales with the superconducting gap and persists above Tc in the pseudogap phase. As the doping decreases, the dispersion of the hump increasingly reflects the wavevector (pi,pi) characteristic of the undoped insulator, despite the presence of a large

M. J. Davis, D. A. W. Hutchinson, E. Zaremba

We present a study of the effects of temperature upon the excitation frequencies of a Bose-Einstein condensate formed within a dilute gas with a weak attractive effective interaction between the atoms. We use the self-consistent Hartree-Fock Bogoliubov treatment within the Popov approximation and compare our results to previous zero temperature and Hartree-F

A. Ramsak, I. Sega, P. Prelovsek

We investigate the c-axis optical conductivity and d.c. resistivity of cuprate superconductors in the normal state. Assuming that the interlayer hopping is incoherent we express the conductivity with planar spectral functions obtained (i) from angle-resolved photoemission experiments, (ii) using marginal Fermi liquid ansatz, and (iii) with the finite-tempera

S. L. Dudarev, L. -M. Peng, S. Y. Savrasov, J. -M. Zuo

Accurate high-energy electron diffraction measurements of structure factors of NiO have been carried out to investigate how strong correlations in the Ni 3d shell affect electron charge density in the interior area of nickel ions and whether the new ab-initio approaches to the electronic structure of strongly correlated metal oxides are in accord with experi

Roman G. Mints, Vladimir G. Kogan

The sin-Gordon equation for Josephson junctions with arbitrary misaligned anisotropic banks is derived. As an application, the problem of Josephson vortices at twin planes of a YBCO-like material is considered. It is shown that for an arbitrary orientation of these vortices relative to the crystal axes of the banks, the junctions should experience a mechanic

M. Y. Choi, Sung Yong Park

The two-dimensional XY gauge glass, which describes disordered superconducting grains in strong magnetic fields, is investigated, with regard to the possibility of a glass transition. We compute the glass susceptibility and the correlation function of the system via extensive numerical simulations and perform the finite-size scaling analysis. This gives stro

Luca Salasnich

We discuss the recently achieved Bose-Einstein condensation for alkali-metal atoms in magnetic traps. The theoretically predicted low-energy collective oscillations of the condensate have been experimentally confirmed by laser imaging techniques. We show by using Poincarè sections that at higher energies non-linear effects appear and oscillations become chao

S. Hozumi, A. Burkert, T. Fujiwara

It is shown that the cuspy density distributions observed in the cores of elliptical galaxies can be realized by dissipationless gravitational collapse. The initial models consist of power-law density spheres such as $ρ\propto r^{-1}$ with anisotropic velocity dispersions. Collapse simulations are carried out by integrating the collisionless Boltzmann equati

V. Vansevicius, A. Vazdekis, F. Prada

A new photometric system suitable for deep, precise and quick metallicity mapping in galaxies is proposed. We find a linear correlation between our metallicity index and the Mg2 index for stellar, globular cluster, and early-type galaxy spectra, and model spectral energy distributions of the simple stellar populations.

Vladas Vansevicius

A new technique is used to derive the extinction and age of populations in the interacting galaxies NGC5194 & NGC5195 from high S/N multicolor photometric data. A new evolutionary scenario of the interaction is proposed.

K. Beuermann, I. Baraffe, P. Hauschildt

The visual surface brightness of K/M giants and dwarfs with near-solar metallicity differ slightly in agreement with the gravity effects predicted by recent theoretical models. We show that M-dwarfs display also a metallicity dependence of the surface brightness in the infrared $K$-band in agreement with theory. Based on these results, we present improved Ba

J. C. Vega Beltran, E. Pignatelli, W. W. Zeilinger, E. M. Corsini

We present a comparison between ionized gas and stellar kinematics for a sample of 5 early-to-intermediate disc galaxies. We measured the major axis V and sigma radial profiles for both gas and stars, and the h3 and h4 radial profiles of the stars. We also derived from the R-band surface photometry of each galaxy the light contribution of their bulges and di

J. Alvarez-Muñiz, R. A. Vázquez, E. Zas

We study the Cherenkov radiopulses emitted in PeV and EeV neutrino interactions in ice. We discuss how the rich radiation pattern in the 100 MHz to 1 GHz frequency range, in principle allows the measurement of shower elongation produced in neutrino interactions opening up the possibility of flavor recognition identifying charged current electron neutrino int

J. Alvarez-Muñiz, E. Zas

We study the longitudinal development of hadronic showers in water and ice for energies up to 100 EeV. We present results of a hybrid Monte Carlo method developed for the purpose of simulating those showers. We show parameterizations of the longitudinal development of hadronic showers in ice and we investigate the implications of the LPM effect on shower dev

R. A. M. J. Wijers, P. M. Vreeswijk, T. J. Galama, E. Rol

Following a BeppoSAX alert (Piro 1999a) and the discovery of the OT at SAAO (Vreeswijk et al. 1999a), we observed GRB 990510 with the FORS instrument on ESO&#39;s VLT Unit 1 (`Antu&#39;). The burst is unremarkable in gamma rays, but in optical is the first one to show good evidence for jet-like outflow (Stanek et al. 1999, Harrison et al. 1999). We report th

Silvia Mollerach, Vicent J. Martinez, J. M. Diego, E. Martinez-Gonzalez

We propose an alternative analysis of the microwave background temperature anisotropy maps that is based on the study of the roughness of natural surfaces. We apply it to large angle anisotropies, such as those measured by COBE-DMR. We show that for a large signal to noise experiment, the spectral index can be determined independently of the normalization. W

Maria-Jesus Pons-Borderia, Vicent J. Martinez, Dietrich Stoyan, Helga Stoyan

We present a systematic comparison of some usual estimators of the 2--point correlation function, some of them currently used in Cosmology, others extensively employed in the field of the statistical analysis of point processes. At small scales, it is known that the correlation function follows reasonably well a power--law expression $ξ(r) \propto r^{-γ}$. T

C. R. Kaiser, P. Alexander

We present a model for the compression and heating of the ICM by powerful radio galaxies and quasars. Based on a self-similar model of the dynamical evolution of FRII-type objects we numerically integrate the hydrodynamic equations governing the flow of the shocked ICM in between the bow shock and the radio lobes of these sources. The resulting gas propertie

G. Pietrzynski, A. Udalski

The list of 127 eclipsing stars in optical coincidence with star clusters from the SMC is presented. It was prepared using the catalogs of eclipsing systems and star clusters from the SMC based on observations collected during the OGLE-II microlensing project. Location of 12 eclipsing stars in the color-magnitude diagram of clusters allows to exclude their m

Matteo Palassini, A. P. Young

We investigate the ground state structure of the three-dimensional Ising spin glass in zero field by determining how the ground state changes in a fixed finite block far from the boundaries when the boundary conditions are changed. We find that the probability of a change in the block ground state configuration tends to zero as the system size tends to infin

Ernesto Galvao, Lucien Hardy

We describe a protocol which can be used to generate any N-partite pure quantum state using Einstein-Podolsky-Rosen (EPR) pairs. This protocol employs only local operations and classical communication between the N parties (N-LOCC). In particular, we rely on quantum data compression and teleportation to create the desired state. This protocol can be used to

R. M. Cavalcanti

I criticize the claim, made in a recent article [C. M. Bender and L. R. Mead, Eur. J. Phys. 20, 117 (1999)], that in order to obtain the correct cross section for the scattering from a two-dimensional delta-function potential one must perform analytic continuation in the dimension of space.

D. Anselmi

Various formulas for currents with arbitrary spin are worked out in general space-time dimension, in the free field limit and, at the bare level, in presence of interactions. As the n-dimensional generalization of the (conformal) vector field, the (n/2-1)-form is used. The two-point functions and the higher-spin central charges are evaluated at one loop. As

O. Utyuzh, G. Wilk, Z. Wlodarczyk

Using simple space-time implementation of the random cascade model we investigate numerically a conjecture made some time ago which was joining the intermittent behaviour of spectra of emitted particles with the possible fractal structure of the emitting source. We demonstrate that such details are seen, as expected, in the Bose-Einstein correlations between

Axel Voelker, Peter Kopietz

We develop a novel eikonal expansion for the Cooperon to study the effect of space- and time-dependent electric fields on the dephasing rate of disordered conductors. For randomly fluctuating fields with arbitrary covariance we derive a general expression for the dephasing rate which is free of infrared divergencies in reduced dimensions. For time-dependent

Prasanta K. Tripathy

We find static spherically symmetric dyons in Einstein-Born-Infeld-Higgs model in 3+1 dimensions. The solutions share many features with the gravitating monopoles in the same model. In particular, they exist only up to some critical value of a parameter $\a$ related to the strength of the gravitational interaction. We also study dyonic non-Abelian black hole

C. Klimcik, S. Parkhomenko

The domain of applicability of the Poisson-Lie T-duality is enlarged to include the gauged WZNW models.

F. Ardalan, H. Arfaei, M. M. Sheikh-Jabbari

We apply the Dirac bracket quantization to open strings attached to branes in the presence of background antisymmetric field and recover an inherent noncommutativity in the internal coordinates of the brane.

Roberto Emparan

We present and analyze exact solutions of the Einstein-Maxwell and Einstein-Maxwell-Dilaton equations that describe static pairs of oppositely charged extremal black holes, i.e., black diholes. The holes are suspended in equilibrium in an external magnetic field, or held apart by cosmic strings. We comment as well on the relation of these solutions to brane-

Sean Gavin, Claude Pruneau

We confront for the first time the widely-held belief that combined event-by-event information from quark gluon plasma signals can reduce the ambiguity of the individual signals. We illustrate specifically how the measured antiproton yield combined with the information from pion-pion HBT correlations can be used to identify novel event classes.

A. I. Agafonov, E. A. Manykin

We point out that the free single-fermion propagator which is used in the QFT equations for two-fermion systems, has a bosonic structure, transforms to the single-boson propagator for the Klein-Gordon equation in the nonrelativistic limit, and, therefore, does not satisfy the Lehmann spectral representation for fermions. Proceeding from the Lippmann-Schwinge

J. Nieves, E. Ruiz Arriola

Using the analysis of ChPT to two loops, we perform an error analysis of the threshold and low energy parameters, based on the uncertainties for the one loop low energy parameters and the resonance saturation mechanism. Different sets of one loop low energy constants have been considered.Thus, the predictive power of the effective field theory is quantified

R. A. Roemer, M. E. Raikh

We study theoretically the exciton absorption on a ring shreded by a magnetic flux. For the case when the attraction between electron and hole is short-ranged we get an exact solution of the problem. We demonstrate that, despite the electrical neutrality of the exciton, both the spectral position of the exciton peak in the absorption, and the corresponding o

J. E. G. Devriendt, B. Guiderdoni, R. Sadat

(abridged) We present STARDUST, a new self-consistent modelling of the spectral energy distributions (SEDs) of galaxies from far-UV to radio wavelengths. In order to derive the SEDs in this broad spectral range, we first couple spectrophotometric and (closed-box) chemical evolutions to account for metallicity effects on the spectra of synthetic stellar popul

Ian J Grivell, Andrew R Liddle

We describe a method of obtaining the inflationary potential from observations which does not use the slow-roll approximation. Rather, the microwave anisotropy spectrum is obtained directly from a parametrized potential numerically, with no approximation beyond linear perturbation theory. This permits unbiased estimation of the parameters describing the pote

P. van Loock, Samuel L. Braunstein

We give a protocol and criteria for demonstrating unconditional teleportation of continuous-variable entanglement (i.e., entanglement swapping). The initial entangled states are produced with squeezed light and linear optics. We show that any nonzero entanglement (any nonzero squeezing) in both of two entanglement sources is sufficient for entanglement swapp

Varghese Mathai

Using Quillen&#39;s superconnection formalism we give a new &#34;twisted&#34; approach to the rational Gromov-Lawson-Rosenberg (GLR) conjecture on topological obstructions to the existence of Riemannian metrics of positive scalar curvature on compact spin manifolds. In particular, we present a short proof of the rational GLR conjecture for word hyperbolic gr

Yue-Liang Wu

The gauge model with $SO(3)_{F}$ flavor symmetry and three Higgs triplets is studied. We show how the intriguing nearly degenerate neutrino mass and bi-maximal mixing scenario comes out naturally after spontaneous breaking of the symmetry. The hierarchy between the neutrino mass-squared differences, which is needed for reconciling both solar and atmospheric

G. P. Berman, V. Ya. Demikhovskii, D. I. Kamenev

Using Husimi function approach, we study the ``quantum phase space&#39;&#39; of a harmonic oscillator interacting with a plane monochromatic wave. We show that in the regime of weak chaos, the quantum system has the same symmetry as the classical system. Analytical results agree with the results of numerical calculations.

A. Marchewka, Z. Schuss

We define a measuring device (detector) of the coordinate of quantum particle as an absorbing wall that cuts off the particle&#39;s wave function. The wave function in the presence of such detector vanishes on the detector. The trace the absorbed particles leave on the detector is identifies as the absorption current density on the detector. This density is

G. M. D&#39;Ariano, L. Maccone, M. G. A. Paris, M. F. Sacchi

We propose a setup capable of generating Fock states of a single mode radiation field. The scheme is based on coupling the signal field to a ring cavity through cross-Kerr phase modulation, and on conditional ON-OFF photodetection at the output cavity mode. The same setup allows to prepare selected superpositions of Fock states and entangled two-mode states.