May 2002 arXiv papers — page 18

M. Kapishin

Recent measurement of inclusive processes and hadronic final states in diffractive deep-inelastic scattering at HERA are used to investigate the QCD factorisation properties and study partonic structure of colour singlet exchange. Resolved Pomeron and colour dipole models are tested by comparison with the data.

A. Weber

This article will summarise the status of current and future long baseline neutrino oscillation experiments.

D. Barna

In order to quantify isospin effects in the comparison of elementary to nuclear collisions, p-p and n-p interactions have been studied in the NA49 experiment in addition to p-Pb and Pb-Pb reactions. Together with first measurements of cascade hyperon and Omega production in p-p collisions, isospin-corrected K/pi ratios and cascade yields are discussed. The A

Olivier Sarbach, Gioel Calabrese, Jorge Pullin, Manuel Tiglio

We discuss an equivalence between the Baumgarte-Shapiro-Shibata-Nakamura (BSSN) formulation of the Einstein evolution equations, a subfamiliy of the Kidder--Scheel--Teukolsky formulation, and other strongly or symmetric hyperbolic first order systems with fixed shift and densitized lapse. This allows us to show under which conditions the BSSN system is, in a

Slava G. Turyshev

This paper is a continuation of our previous analysis (i.e. Turyshev 2002a, 2002b) of the relativistic stellar aberration requirements for the Space Interferometry Mission (SIM). Here we have considered a problem of how the expected astrometric accuracy of parallax determination will constrain the accuracy of the spacecraft navigation. We show that effect of

Slava G. Turyshev

We address the issue of relativistic stellar aberration requirements for the Space Interferometry Mission (SIM). Motivated by the importance of this issue for SIM, we have considered a problem of relative astrometric observations of two stars separated by angle $θ$ on the sky with a single baseline interferometer. While a definitive answer on the stellar abe

Slava G. Turyshev

This paper analyses the relativistic stellar aberration requirements for the Space Interferometry Mission (SIM). We address the issue of general relativistic deflection of light by the massive self-gravitating bodies. Specifically, we present estimates for corresponding deflection angles due to the monopole components of the gravitational fields of a large n

Pedro F. Gonzalez-Diaz

This letter deals with an analysis of the space-time static metric that corresponds to a quintessential state equation with constant characteristic parameter. Following a procedure parallel to as it is used in the case of de Sitter space, we have tried to generalize the metric components that correspond to the quintessential case to also embrace black-hole t

T. P. Singh

In a recent paper we have suggested that a formulation of quantum mechanics should exist, which does not require the concept of time, and that the appropriate mathematical language for such a formulation is noncommutative differential geometry. In the present paper we discuss this formulation for the free point particle, by introducing a commutation relation

Evgueniy Vitchev

We give an implementation of a statistical model, which can be successfully applied for compressing of a sequence of binary digits with behavior close to random.

Dirk K. Morr, Nikolaos A. Stavropoulos

We demonstrate that quantum interference of electronic waves that are scattered by multiple magnetic impurities in an s-wave superconductor gives rise to novel bound states. We predict that by varying the inter-impurity distance or the relative angle between the impurity spins, the states' quantum numbers, as well as their distinct frequency and spatial

Uwe C. Tauber

Many non-equilibrium systems display dynamic phase transitions from active to absorbing states, where fluctuations cease entirely. Based on a field theory representation of the master equation, the critical behavior can be analyzed by means of the renormalization group. The resulting universality classes for single-species systems are reviewed here. Generica

Harald Lange, Friederike Schmid

We present a Monte Carlo study of the surface anchoring of a nematic fluid on swollen layers of grafted liquid crystalline chain molecules. The liquid crystalline particles are modeled by soft repulsive ellipsoids, and the chains are made of the same particles. An appropriately modified version of the configurational bias Monte Carlo algorithm is introduced,

Harald Lange, Friederike Schmid

By Monte Carlo simulations of a soft ellipsoid model for liquid crystals, we study whether a layer of grafted liquid-crystalline chain molecules can induce tilt in a nematic fluid. The chains are fairly short (four monomers) and made of the same particles as the solvent. They are attached to a substrate which favors parallel (planar) alignment. At low grafti

R. Reigada, A. Sarmiento, Katja Lindenberg

We study the asymptotic dynamics of breathers in finite Fermi-Pasta-Ulam chains at zero and non-zero temperatures. While such breathers are essentially stationary and very long-lived at zero temperature, thermal fluctuations tend to lead to breather motion and more rapid decay.

Ronald Dickman, Ronaldo Vidigal

We review and extend the formalism introduced by Peliti, that maps a Markov process to a path-integral representation. After developing the mapping, we apply it to some illustrative examples: the simple decay process, the birth-and-death process, and the Malthus-Verhulst process. In the first two cases we show how to obtain the exact probability generating f

Gudrun Ehrenstein

The Tobin tax is an often discussed method to tame speculation and get a source of income. The discussion is especially heated when the financial markets are in crisis. In this article we refer to foreign exchange markets. The Tobin tax should be a small international tax affecting all currency transactions and thus consequently reducing the destabilizing sp

Kevin Gross, Chris P. Search, Han Pu, Weiping Zhang

We study the ground state magnetic properties of ferromagnetic spinor Bose-Einstein condensates confined in a deep optical lattices. In the Mott insulator regime, the ``mini-condensates'' at each lattice site behave as mesoscopic spin magnets that can interact with neighboring sites through both the static magnetic dipolar interaction and the light-i

Ndeye Fama Diagne, James Lindesay, Michael Spencer

Flexural Plate Wave (FPW) devices fabricated from Silicon Carbide (SiC) membranes are presented here which exhibit electrical and mechanical characteristics in its transfer functions that makes it very useful as a low voltage probe device capable of functioning in small areas that are commonly inaccessible to ordinary devices. The low input impedance charact

Emmanuel I. Rashba

Diffusive theory of spin injection is reviewed and a number of new results is presented for the dc and ac regimes. They were derived by means of the "gamma-technique" allowing to simplify the calculations by choosing the spin injection coefficients through different interfaces as the basic variables. The prospects for increasing spin injection by usi

N. M. Chtchelkatchev, W. Belzig, C. Bruder

We investigate the Josephson effect in S$_{\rm F}$XS$_{\rm F}$ junctions, where S$_{\rm F}$ is a superconducting material with a ferromagnetic exchange field, and X a weak link. The critical current $I_c$ increases with the (antiparallel) exchange fields if the distribution of transmission eigenvalues of the X-layer has its maximum weight at small values. Th

M. K. Hassan, J. Schmidt, B. Blasius, J. Kurths

We propose a generalized car parking problem where either a car of size $σ$ or of size $mσ$ ($m>1$) is sequentially parked on a line with probability $q$ and $(1-q)$, respectively. The free parameter $q$ interpolates between the classical car parking problem at either extreme ($q=0$ and $q=1$) and the competitive random sequential adsorption of a binary mixt

Prasenjit Sen, O. Gulseren, T. Yildirim, Inder P. Batra

We performed an extensive first-principles study of nanowires in various pentagonal structures by using pseudopotential plane wave method within the density functional theory. Our results show that nanowires of different types of elements, such as alkali, simple, transition and noble metals and inert gas atoms, have a stable structure made from staggered pen

Nicolas Vandewalle, Serge Galam

A 1-d Ising model is shown to reproduce qualitatively the dynamics of ripple formation. Saltation effect is imposed using a Kawasaki dynamics and a pair interaction over some distance l. Within this model, the ripple state turns out to be metastable in agreement with cellular automata simulations as well as recent under water experiments. A dynamical phase d

Markus Keil, Herbert Schoeller

Transport through coupled quantum dots in a phonon bath is studied using the recently developed real-time renormalization-group method. Thereby, the problem can be treated beyond perturbation theory regarding the complete interaction. A reliable solution for the stationary tunnel current is obtained for the case of moderately strong couplings of the dots to

Noelle Pottier

We report new results about the two-time dynamics of an anomalously diffusing classical particle, as described by the generalized Langevin equation with a frequency-dependent noise and the associated friction. The noise is defined by its spectral density proportional to $ω^{δ-1}$ at low frequencies, with $0<δ<1$ (subdiffusion) or $1<δ<2$ (superdiffusion). Us

N. Freytag, M. Horvatić, C. Berthier, M. Shayegan

NMR measurements of the electron spin polarization have been performed on a 2D electron system at and around half-filled lowest Landau level. Comparing the magnetic field and the temperature dependence of the spin polarization to models of free and interacting composite fermions (CF), we confirm the existence of a Fermi sea and show that residual interaction

T. Schneider

We analyze the empirical correlation between the zero temperature penetration depth $λ_{c}(0) $ and the corresponding normal state DC conductivity $σ_{c}^{DC}$, measured slightly above the transition temperature $T_{c}$, in different classes of quasi two-dimensional superconductors, including cuprates and organics. For this purpose we invoke the scaling theo

A. V. Fokin, Yu. A. Kumzerov, N. M. Okuneva, A. A. Naberezhnov

The NaNO$_{2}$ nanocomposite ferroelectric material in porous glass was studied by neutron diffraction. For the first time the details of the crystal structure including positions and anisotropic thermal parameters were determined for the solid material, embedded in a porous matrix, in ferro- and paraelectric phases. It is demonstrated that in the ferroelect

Wei Ku, H. Rosner, W. E. Pickett, R. T. Scalettar

Microscopic mechanisms of the puzzling insulating ferromagnetism of half-filled La$_{4}$Ba$_{2}$Cu$_{2}$O$_{10}$ are elucidated with energy-resolved Wannier states. The dominant magnetic coupling, revealed through evaluated parameters ($t$, $U$, and $J$), turns out to be the intersite direct exchange, a currently ignored mechanism that overwhelms the antifer

J-M. Maillard

We will try to sketch Professor F. Y. Wu&#39;s contributions in lattice statistical mechanics, solid state physics, graph theory, enumerative combinatorics and so many other domains of physics and mathematics. We will recall F. Y. Wu&#39;s most important and well-known classic results and we will also sketch his most recent researches dedicated to the connec

Remi Carles

We use a change of variables that turns the critical nonlinear Schroedinger equation into the critical nonlinear Schroedinger equation with isotropic harmonic potential, in any space dimension. This change of variables is isometric on $L^2$, and bijective on some time intervals. Using the known results for the critical nonlinear Schroedinger equation, this p

Florian W. Beil, Laura Pescini, Eva Höhberger, Andreas Kraus

We present measurements on nanomechanical resonators operating in the radio frequency range. We apply a setup which allows the comparison of two schemes of displacement detection for mechanical resonators, namely conventional power reflection measurements of a probing signal and direct detection by capacitive coupling via a gate electrode. For capacitive det

Yeshe Fenner, Brad K. Gibson, Marco Limongi

We present a dual-infall galactic chemical evolution model which uses a new set of stellar yields calculated by Limongi et al (2001) to constrain the amount of iron-peak elements ejected by massive stars. The age-metallicity relation, G-dwarf distribution and evolution of abundance ratios are predicted using Galaxy Evolution tool (GEtool), a software package

Roberta M. Humphreys, Kris Davidson, Nathan Smith

IRC +10420 is one of the extreme hypergiant stars that define the empirical upper luminosity boundary in the HR diagram. During their post--RSG evolution, these massive stars enter a temperature range (6000-9000 K) of increased dynamical instability, high mass loss, and increasing opacity, a semi--forbidden region, that de Jager and his collaborators have ca

Timothy M. Brown, Kenneth G. Libbrecht, David Charbonneau

We observed one transit of the extrasolar planet HD 209458b with the NIRSPEC spectrograph on the Keck II telescope. Using time series of low-noise observations in the wavelength range 2.0 micron to 2.5 micron, we searched for extra absorption from the 1st overtone rotation-vibration band of CO near 2.3 micron. This was not detected, with a detection limit th

F. Perrotta, C. Baccigalupi

In the general context of scalar-tensor theories, we consider a model in which a scalar field coupled to the Ricci scalar in the gravitational sector of the Lagrangian, is also playing the role of an ``Extended Quintessence&#39;&#39; field, dominating the energy content of the Universe at the present time. In this framework, we study the linear evolution of

K. E. McGowan, P. A. Charles

Long-term variations are well-known in Be X-ray binaries, and are attributed to non-orbital changes in the structure of the Be circumstellar (equatorial) disc. However, the timescales involved are so long (tens of days, to years) that systematic studies have been very restricted. The ~8 year MACHO monitoring of the Large Magellanic Cloud (LMC) therefore pres

S. J. Smartt, P. M. Vreeswijk, E. Ramirez-Ruiz, G. F. Gilmore

This letter presents wide-field optical and and NIR UBVRI,Halpha,K&#39; images of the galaxy M74 which were taken between 0.6-8.3 years before the discovery of the Type Ic SN2002ap. We have located the position of the SN on these images with an accuracy of 0.3&#39;&#39;. We find no sign of a progenitor object on any of the images. The deepest of these images

Tae-Sun Kim, Robert F. Carswell, Stefano Cristiani, Sandro D&#39;Odorico

Combining a new, increased dataset of 8 QSOs covering the Ly-alpha forest at redshifts 1.5 < z < 3.6 from VLT/UVES observations with previously published results, we have investigated the properties of the Ly-alpha forest at 1.5 < z < 4. We have fitted Voigt profiles to the Ly-alpha absorption lines as in previous studies, and have, for two QSOs, fitted Ly-a

Greg Huey, James E. Lidsey

Scalar and tensor perturbations arising in an inflationary braneworld scenario driven by a single scalar field are considered, where the bulk on either side of the brane corresponds to Anti-de Sitter spaces with different cosmological constants. A consistency relation between the two spectra is derived and found to have an identical form to that arising in s

Jacco Vink, J. Martin Laming

We discuss the detection of Sc-44 (product of Ti-44) in the supernova remnant Cas A with the BeppoSAX-PDS instrument, and elaborate on the nature of the hard X-ray continuum, which is not only important for correctly estimating the Sc-44 flux, but is interesting in its own right. We apply the lower hybrid wave electron acceleration model to the hard X-ray da

N. Kleeorin, I. Rogachevskii, D. Sokoloff

Magnetic fluctuations with a zero mean field in a random flow with a finite correlation time and a small yet finite magnetic diffusion are studied. Equation for the second-order correlation function of a magnetic field is derived. This equation comprises spatial derivatives of high orders due to a non-local nature of magnetic field transport in a random velo

E. Depagne, V. Hill, M. Spite, F. Spite

CS 22949--037 is one of the most metal-poor giants known ([Fe/H]$ \approx-4.0$), and it exhibits large overabundances of carbon and nitrogen (Norris et al.). Using VLT-UVES spectra of unprecedented quality, regarding resolution and S/N ratio, covering a wide wavelength range (from $λ= 350$ to 900 nm), we have determined abundances for 21 elements in this sta

T. Belloni, A. P. Colombo, J. Homan, S. Campana

We present the results of the analysis of 11 RXTE/PCA observations of the January 2002 outburst of the black-hole transient XTE J1550-564. The outburst was rather short, with an e-folding time of ~11 days in the PCA band 3-25 keV. The source was seen in an extreme low/hard state. The energy spectra could be fitted with a power law slightly steepening (Gamma

L. Amati, F. Frontera, M. Tavani, J. J. M. in &#39;t Zand

We present the main results of a study of spectral and energetics properties of twelve gamma-ray bursts (GRBs) with redshift estimates. All GRBs in our sample were detected by BeppoSAX in a broad energy range (2-700 keV). From the redshift estimates and the good-quality BeppoSAX time-integrated spectra we deduce the main properties of GRBs in their cosmologi

X. Kong, F. Z. Cheng

Blue compact galaxies are compact objects that are dominated by intense star formation. Most of them have dramatically different properties compared to the Milky Way and many other nearby galaxies. Using the IRAS, HI data, and optical spectra, we wanted to measure the current star formation rates, stellar components, metallicities, and star formation histori

G. Ghisellini, D. Lazzati, E. M. Rossi, M. J. Rees

The emission features observed in the X-ray afterglow of Gamma Ray Bursts are extremely powerful. Since they last at least for several hours, they imply energies of the order of 1e49 ergs. This in turn implies that the energy contained in the illuminating continuum thought to be responsible of the line production must exceed 1e51 ergs. This is a strong lower

Davor Krajnovic, Walter Jaffe

We have surveyed an optical/IR selected sample of nearby E/S0 galaxies with and without nuclear dust structures with the VLA at 3.6 cm to a sensitivity of 100 $μ$Jy. We can construct a Radio Luminosity Function (RLF) of these galaxies to ~10^19 W/Hz and find that ~50% of these galaxies have AGNs at this level. The space density of these AGNs equals that of s

A. M. Bykov

We show that fast moving isolated fragments of a supernova ejecta composed of heavy elements should be sources of K_alpha X-ray line emission of the SN nuclear-processed products. Supersonic motion of the knots in the intercloud medium will result in a bow-shock/knot-shock structure creation. Fast nonthermal particles accelerated by Fermi mechanism in the MH

Agnieszka Wozna, Jaroslaw Dyks, Tomasz Bulik, Bronislaw Rudak

We calculate the gamma-ray lightcurves and spectra of rotation powered pulsars for a wide range of observer&#39;s viewing angles, and inclination angles of the magnetic axis to the rotation axis. We show how the shapes of the observed phase-averaged spectra as well as energy-integrated pulse profiles depend on the orientation for classical and millisecond pu

Steen Hannestad

We have performed a careful analysis of constraints on the neutrino mass from current cosmological data. Combining data from the cosmic microwave background and the 2dF galaxy survey yields an upper limit on the sum of the three neutrino mass eigenstates of \sum m_nu < 3 eV (95% conf.), without including additional priors. Including data from SNIa observatio

J. Dyks, B. Rudak

We interpret the unique high-energy spectrum of the millisecond pulsar PSR J0218+4232 within polar cap scenarios. We show that the spectral data from BeppoSAX (Mineo et al.2000) and EGRET (Kuiper et al 2000) impose very restrictive limitations on possible radiation mechanisms, energy spectrum of radiating charges as well as viewing geometry. Theoretical spec

Agnieszka Janiuk, Bozena Czerny, Aneta Siemiginowska

The time dependent evolution of the accretion disk around black hole is computed. The classical description of the $α$-viscosity is adopted so the evolution is driven by the instability operating in the innermost radiation-pressure dominated part of the accretion disk. We assume that the optically thick disk always extends down to the marginally stable orbit

A. M. Piersimoni, G. Bono, V. Ripepi

We present Johnson BV, and Kron-Cousins I-band time series data collected over three consecutive nights in a region of 13 arcmin^2 centered on the Galactic Globular Cluster (GGC) NGC3201. The time sampling of current CCD data allowed us to derive accurate light curves, and in turn mean magnitudes and colors for a sample of 53 RR Lyrae. To overcome the thorny

Debasish Majumdar, Kamales Kar

The half lives are calculated for the process of $β^\pm$ decay and electron capture for nuclei in mass range $\sim$ 65 - 100 relevant for the core of a massive star at late burning stage of steller evolution that leads to supernova explosion. The rates of electron capture process are also computed for nuclei relevant during presupernova stage of massive star

C. Baccigalupi, A. Balbi, S. Matarrese, F. Perrotta

A dynamical scalar field represents the simplest generalization of a pure Cosmological Constant as a candidate to explain the recent evidence in favour of the accelerated cosmic expansion. We review the dynamical properties of such a component, and argue that, even if the background expectation value of this field is fixed and the equation of state is the sa

K. Nandra, R. F. Mushotzky, K. A. Arnaud, C. C. Steidel

We describe the X-ray properties of a large sample of $z\sim3$ Lyman Break Galaxies (LBGs) in the region of the Hubble Deep Field North, derived from the 1 Ms public Chandra observation. Of our sample of 148 LBGs, four are detected individually. This immediately gives a measure of the bright AGN fraction in these galaxies of $\sim 3$~per cent, which is in ag

Asantha Cooray, Alessandro Melchiorri, Joseph Silk

The primordial anisotropies of the cosmic microwave background (CMB) are linearly polarized via Compton-scattering. The Faraday conversion process during the propagation of polarized CMB photons through regions of the large-scale structure containing magnetized relativistic plasma, such as galaxy clusters, will lead to a circularly polarized contribution. Th

L. Binette, M. Rodriguez-Martinez, I. Ballinas

The ionizing spectral energy distribution of quasars exhibits a steepening of the distribution short-ward of 1200 A. The change of the power-law index from approximately -1 to -2 so far has been interpreted as being intrinsic to quasars. We study an alternative interpretation, in which a tenuous absorption screen is responsible for the change of index. We fi

Luc Binette, Mario Rodriguez-Martinez, Isidro Ballinas

The ionizing spectral energy distribution of quasars is known to exhibit a steepening of the distribution short-ward of 1050Å. It has been assumed that this change of power-law index from -1 to -2 is intrinsic to the quasars. We study an alternative interpretation, in which a tenuous absorption screen is responsible for the change of index. A successful spec

Michael Efroimsky

Whenever a freely spinning body is found in a complex rotational state, this means that either the body is a recent victim of an impact or a tidal interaction, or is a fragment of a recently disrupted progenitor. Another factor (relevant for comets) is outgassing. Due to impacts, tidal forces and outgassing, the asteroidal and cometary precession must be a g

M. B. Halpern, F. Wagner

Recently an action formulation, called the general WZW orbifold action, was given for each sector of every WZW orbifold. In this paper we gauge this action by general twisted gauge groups to find the action formulation of each sector of every coset orbifold. Connection with the known current-algebraic formulation of coset orbifolds is discussed as needed, an

N. Stefanakis

We describe the dynamics of fluxons moving in a frustrated Josephson junction with p, d, and f-wave symmetry and calculate the I-V characteristics. The behavior of fluxons is quite distinct in the long and short length junction limit. For long junctions the intrinsic flux is bound at the center and the moving integer fluxon or antifluxon interacts with it on

A. P. C. Malbouisson

By considering the large-N Ginzburg-Landau model, compactified in one of the spatial dimensions, we determine the beta-function and find an infrared stable fixed point for a superconducting film for dimensions $4<D<6$. We find that this fixed point is independent of the film thickness ($L$). For the physical dimension D=3 we conclude that if a transition exi

J. Jaroszynski, T. Andrearczyk, G. Karczewski, J. Wrobel

We report on the observation of the Ising quantum Hall ferromagnet with Curie temperature $T_C$ as high as 2 K in a modulation-doped (Cd,Mn)Te heterostructure. In this system field-induced crossing of Landau levels occurs due to the giant spin-splitting effect. Magnetoresistance data, collected over a wide range of temperatures, magnetic fields, tilt angles,

R. A. Konoplya

We compute the quasinormal modes associated with decay of the massless scalar filed around a small Schwarzschild-Anti-de-Sitter black hole. The computations shows that when the horizon radius is much less than the anti-de-Sitter radius, the imaginary part of the frequency goes to zero as $r_+^{d-2}$ while the real part of $ω$ decreases to its minimum and the

F. H. L. Essler, A. M. Tsvelik

We calculate the low temperature spectral function of one-dimensional incommensurate charge density wave (CDW) states and half-filled Mott insulators (MI). At $T=0$ there are two dispersing features associated with the spin and charge degrees of freedom respectively. We show that already at very low temperatures (compared to the gap) one of these features ge

M. Angst, R. Puzniak, A. Wisniewski, J. Jun

Measurements of single crystalline MgB2 with torque magnetometry in fields up to 90 kOe reveal a sharp peak in the irreversible torque at about 0.85 Hc2. In the region between peak onset and maximum, pronounced history effects occur. Angle and temperature dependence of the characteristic peak fields track those of Hc2. The features observed suggest that the

Anton Yu. Alekseev, Stefan Fredenhagen, Thomas Quella, Volker Schomerus

In this work we propose new non-commutative gauge theories that describe the dynamics of branes localized along twisted conjugacy classes on group manifolds. Our proposal is based on a careful analysis of the exact microscopic solution and it generalizes the matrix models (`fuzzy gauge theories&#39;) that are used to study e.g. the bound state formation of p

J. McDonald, D. Naples, C. Velissaris, A. Erwin

Radiation-hard ionization chambers were tested using an intense electron beam from the accelerator test facility (ATF) at the Brookhaven National Laboratory (BNL). The detectors were designed to be used as the basic element for monitoring muons in the Main Injector Neutrino beamline (NuMI) at the Fermi National Accelerator Laboratory (FNAL). Measurements of

Robert V. Kowalewski, Sven Menke

The determination of |Vub| from inclusive semileptonic B decays is limited by uncertainties in modelling the decay distributions in b->ulnu transitions. The largest uncertainties arise from the limited knowledge of the appropriate b quark mass and Fermi momentum to use in the parameterization of the shape function. This paper presents a new method in which t

Konstantin N. Borozdin, Sergey P. Trudolyubov

We present the XMM-Newton observations of X-ray afterglows of the gamma-ray bursts GRB 011211 and GRB 001025. For GRB 011211 XMM detected fading X-ray object with an average flux in 0.2-10 keV declining from 2.7$\times10^{-13}$ erg cm$^{-2}$ s$^{-1}$ during the first 5 ks of 27-ks observation to 1.0$\times10^{-13}$ erg cm$^{-2}$ s$^{-1}$ toward the end of th

A. Alonso Izquierdo, W. Garcia Fuertes, M. A. Gonzalez Leon, J. Mateos Guilarte

We use the generalized zeta function regularization method to compute the one-loop quantum correction to the masses of the TK1 and TK2 kinks in a deformation of the O(N) linear sigma model on the real line.

Samir D. Mathur, Ashish Saxena, Yogesh K. Srivastava

We compute the propagator for massless and massive scalar fields in the metric of the pp-wave. The retarded propagator for the massless field is found to stay confined to the surface formed by null geodesics. The algebraic form of the massive propagator is found to be related in a simple way to the form of the propagator in flat spacetime.

R. P. Malik

Some of the key cohomological features of the two $(1+1)$-dimensional (2D) free Abelian- and self-interacting non-Abelian gauge theories (having no interaction with matter fields) are briefly discussed first in the language of symmetry properties of the Lagrangian densities and the same issues are subsequently addressed in the framework of superfield formula

Mohsen Alishahiha, Alok Kumar

We use recently proposed translations isometries of pp-waves to construct D4 and D3 brane solutions, using T-duality transformations, in exactly solvable pp-wave background originating from $AdS_3\times S^3$ geometry. A unique property of the new brane solutions is the breaking of SO(10-p-1) symmetry in the transverse direction of the branes due to the prese

M. A. Perez-Torres, A. Alberdi, J. M. Marcaide

We present VLA radio continuum measurements of SN1993J in M81 at the frequencies of 0.32 (P-band), 1.3 and 1.7 (L-band), 4.9 (C-band), 8.5 (X-band), and 14.9 (U-band) GHz carried out on December 17 and 21, 2000, about 2820 days after the supernova explosion. We find that a power-law spectrum, free-free absorbed by an homogeneous, or clumpy, distribution of i

Arthur Hebecker, John March-Russell

In supersymmetric grand unified theories (GUTs) based on S^1/(Z_2 x Z&#39;_2) orbifold constructions in 5 dimensions, Standard Model (SM) matter and Higgs fields can be realized in terms of 5d hypermultiplets. These hypermultiplets can naturally have large bulk masses, leading to a localization of the zero modes at one of the two branes or to an exponential

UA8 Collaboration, A. Brandt, J. B. Cheze, S. Erhan

We report measurements of the inclusive reaction, p pbar -> p X pbar, in events where either or both the beam-like final-state baryons were detected in Roman-pot spectrometers and the central system was detected in the UA2 calorimeter. A Double-Pomeron-Exchange (DPE) analysis of these data and single diffractive data from the same experiment demonstrates tha

Carla Biggio

We discuss a new method for gauge symmetry breaking in theories with one extra dimension compactified on the orbifold S^1/Z_2. If we assume that fields and their derivatives can jump at the orbifold fixed points, we can implement a generalized Scherk-Schwarz mechanism that breaks the gauge symmetry. We show that our model with discontinuous fields is equival

J. -L. Kneur, D. Reynaud

We reconsider in some detail a construction allowing (Borel) convergence of an alternative perturbative expansion, for specific physical quantities of asymptotically free models. The usual perturbative expansions (with an explicit mass dependence) are transmuted into expansions in 1/F, where $F \sim 1/g(m)$ for $m \gg Λ$ while $F \sim (m/Λ)^α$ for $m \lsim Λ

Marco Bertola

We introduce the notion of bilinear moment functional and study their general properties. The analogue of Favard&#39;s theorem for moment functionals is proven. The notion of semi-classical bilinear functionals is introduced as a generalization of the corresponding notion for moment functionals and motivated by the applications to multi-matrix random models.

E. Sezgin, P. Sundell

The minimal bosonic higher spin gauge theory in four dimensions contains massless particles of spin s=0,2,4,.. that arise in the symmetric product of two spin 0 singletons. It is based on an infinite dimensional extension of the AdS_4 algebra a la Vasiliev. We derive an expansion scheme in which the gravitational gauge fields are treated exactly and the grav

E. Sezgin, P. Sundell

We treat free large N superconformal field theories as holographic duals of higher spin (HS) gauge theories expanded around AdS spacetime with radius R. The HS gauge theories contain massless and light massive AdS fields. The HS current correlators are written in a crossing symmetric form including only exchange of other HS currents. This and other arguments

Bruno Kahn

This is an update of the first version. We clarify that the main results apply to more general smooth projective varieties X than products of elliptic curves (briefly: X is of &#34;abelian type&#34;, e.g. an abelian variety or a product of curves, and the Tate conjecture holds). We also deduce the Gersten conjecture for dvrs whose residue field is the functi

Brent Everitt

The rich theory of Coxeter groups is used to provide an algebraic construction of finite volume hyperbolic n-manifolds. Combinatorial properties of finite images of these groups can be used to compute the volumes of the resulting manifolds. Three examples, in 4,5 and 6-dimensions, are given, each of very small volume, and in one case of smallest possible vol

N. J. MacKay

We describe the twisted Yangians Y(g,h) which arise as boundary remnants of Yangians Y(g) in 1+1D integrable field theories. We describe and extend our recent construction of the intertwiners of their representations (the rational boundary S- or &#39;K&#39;-matrices) and perform a case-by-case analysis for all pairs (g,h), giving the h-decomposition of Y(g,h

G. L. Kotkin, V. G. Serbo, V. I. Telnov

In a number of papers an attractive method of laser polarization of electrons (positrons) at storage rings or linear colliders has been proposed. We show that these suggestions are incorrect and based on errors in simulation of multiple Compton scattering and in calculation of the Compton spin-flip cross sections. We argue that the equilibrium polarization i

M. H. Dehghani

We use the anti-de Sitter (AdS) conformal field theory correspondence to calculate the conserved charges and the Euclidean actions of the charged rotating black string in four dimensions both in the canonical and the grand-canonical ensemble. The four-dimensional solution of the Einstein-Maxwell equations with a positive cosmological constant is introduced,

Bethany Marsh, Markus Reineke, Andrei Zelevinsky

We provide a quiver-theoretic interpretation of certain smooth complete simplicial fans associated to arbitrary finite root systems in recent work of S. Fomin and A. Zelevinsky. The main properties of these fans then become easy consequences of the known facts about tilting modules due to K. Bongartz, D. Happel and C. M. Ringel.

E. Batista, S. Majid

We study the standard angular momentum algebra $[x_i,x_j]=iλε_{ijk}x_k$ as a noncommutative manifold $R^3_λ$. We show that there is a natural 4D differential calculus and obtain its cohomology and Hodge * operator. We solve the spin 0 wave equation and some aspects of the Maxwell or electromagnetic theory including solutions for a uniform electric current de

T. Blomquist

The conductance through open quantum dots or quantum billiards shows fluctuations, that can be explained as interference between waves following different paths between the leads of the billiard. We examine such systems by the use of a semi-classical Green&#39;s functions. In this paper we examine how the choice of boundary conditions at the lead mouths affe

Caslav Brukner, Marek Zukowski, Anton Zeilinger

We formulate a two-party communication complexity problem and present its quantum solution that exploits the entanglement between two qutrits. We prove that for a broad class of protocols the entangled state can enhance the efficiency of solving the problem in the quantum protocol over any classical one if and only if the state violates Bell&#39;s inequality

B. Doliwa, A. Heuer

We investigate the jump motion among potential energy minima of a Lennard-Jones model glass former by extensive computer simulation. From the time series of minima energies, it becomes clear that the energy landscape is organized in superstructures, called metabasins. We show that diffusion can be pictured as a random walk among metabasins, and that the whol

Ralf Laemmel

A typed model of strategic term rewriting is developed. The key innovation is that generic traversal is covered. To this end, we define a typed rewriting calculus S&#39;_{gamma}. The calculus employs a many-sorted type system extended by designated generic strategy types gamma. We consider two generic strategy types, namely the types of type-preserving and t

H. Ishino

In this paper, we report on the results of the |Vcb| and |Vub| measurements obtained from studies of inclusive and exclusive semileptonic decays using 30fb^-1 of e^+e^- collision data collected by the Belle detector at KEKB.

Bing Dong, X. L. Lei

The linear and nonlinear transport through a multi-level lateral quantum dot connected to two leads is investigated using a generalized finite-$U$ slave-boson mean field approach. For a two-level quantum dot, our calculation demonstrates a substantial conductance enhancement near the degeneracy point of the spin singlet and triplet states, a non-monotonic te

S. A. Pustilnik, J. -M. Martin, W. K. Huchtmeier, N. Brosch

We present here results of studies of the properties of galaxies located in very low density environments. We observed 26 blue compact galaxies (BCGs) from the Second Byurakan (SBS) and Case surveys located in voids with the radial velocities V < 11000 km/s, two BCGs in the void behind the Virgo cluster and 11 BCGs in denser environments. HI fluxes and profi

Cai-Dian Lü, Zhenjun Xiao

In this paper, we study and try to find the constraint on the CKM angle alpha from the experimental measurements of CP violation in B_d^0 --> pi^+ pi^- decay, as reported very recently by BaBar and Belle Collaborations. After considering uncertainties of the data and the ratio r of penguin over tree amplitude, we found that strong constraint on both the CKM