arXiv papers from July 2002

Paul Martini, Daniel D. Kelson, John S. Mulchaey, Scott C. Trager

As part of a program to study the evolution of active galactic nuclei (AGN) in clusters of galaxies, we present our results for Abell 2104. A deep Chandra observation of this massive, z = 0.154 cluster reveals a significant X-ray point source excess over the expectations of blank fields, including eight X-ray counterparts with R<20 mag. Our spectroscopy show

M. Mouhcine

In this paper,we present single stellar population models of intermediate age stellar populations where dust-enshrouded AGB stars are introduced. The formation of carbon stars is also accounted for, and is taken to be a function of both initial mass and metallicity. The effect of the dusty envelopes around AGB stars on the optical/near-infrared spectral ener

Pranaw Rungta, Carlton M. Caves

We discuss properties of entanglement measures called I-concurrence and tangle. For a bipartite pure state, I-concurrence and tangle are simply related to the purity of the marginal density operators. The I-concurrence (tangle) of a bipartite mixed state is the minimum average I-concurrence (tangle) of ensemble decompositions of pure states of the joint dens

Bernard Leong, Anthony Challinor, Roy Maartens, Anthony Lasenby

Cosmic microwave background (CMB) observations provide in principle a high-precision test of models which are motivated by M theory. We set out the framework of a program to compute the tensor anisotropies in the CMB that are generated in braneworld models. In the simplest approximation, we show the braneworld imprint as a correction to the power spectra for

Gerry Bunce

The RHIC spin program will probe the spin structure of the proton with polarized quarks and gluons by colliding beams of polarized protons at Brookhaven. The first collisions, at sqrt(s)=200GeV, were recorded this year in December 2001 and January 2002. This report describes the first run, and our plans for the next five+ years, with planned runs at sqrt(s)=

Joel Giedt

The matter sector of four-dimensional effective supergravity models obtained from the weakly coupled heterotic string contains many moduli. In particular, flat directions of the D-term part of the scalar potential in the presence of an anomalous U(1) give rise to massless chiral multiplets which have been referred to elsewhere as D-moduli. The stabilization

Jeonghee Rho, Kristy K. Dyer, Kazimierz J. Borkowski, Stephen P. Reynolds

Supernova remnants may exhibit both thermal and nonthermal X-ray emission. We present Chandra observations of RCW 86. Striking differences in the morphology of X-rays below 1 keV and above 2 keV point to a different physical origin. Hard X-ray emission is correlated fairly well with the edges of regions of radio emission, suggesting that these are the locati

M. Dzero, L. P. Gor'kov, V. Z. Kresin

We use the double exchange (DE) model via degenerate orbitals and tight-binding approximation to study the magnetoconductivity of a canted A-phase of pseudo-cubic manganites. It is argued that the model is applicable in a broad concentration range for manganites with the tolerance factor, t, close to one. As for the substitutional disorder, scattering on ran

Knox S. Long, Christian Knigge

Bipolar outflows are present in many disk-accreting astrophysical systems. In disk-accreting cataclysmic variables (CVs), these outflows are responsible for most of the strong features in the ultraviolet spectra of these systems. However, there have been few attempts to model these features quantitatively. Here, we describe a new, hybrid Monte Carlo/Sobolev

R. J. Fries, B. Müller, D. K. Srivastava

We calculate the production of high energy photons from Compton scattering and annihilation of a quark jet passing through a quark gluon plasma produced in a relativistic heavy ion collision. The contributions are large and reflect the momentum distribution of the jets and the initial conditions of the plasma.

S. J. Akhtarshenas, M. A. Jafarizadeh

Hilbert-Schmidt distance reduces to Euclidean distance in Bell decomposable states. Based on this, entanglement of these states are obtained according to the protocol proposed in Ref. [V. Vedral et al, Phys. Rev. Lett. 78, 2275 (1995)] with Hilbert-Schmidt distance. It is shown that this measure is equal to the concurrence and thus can be used to generate en

Craig J. Copi, Lawrence M. Krauss

We compare the sensitivity of WIMP detection via direct separation of possible signal vs. background to WIMP detection via detection of an annual modulation, in which signal and background cannot be separated on an event-by-event basis. In order to determine how the constraints from the two different types of experiments might be combined an adequate incorpo

P. Moskal, M. Wolke, A. Khoukaz, W. Oelert

Studies of meson production at threshold in the hadron--hadron interaction began in the fifties when sufficient energies of accelerated protons were available. A strong interdependence between developments in accelerator physics, detector performance and theoretical understanding led to a unique vivid field of physics. Early experiments performed with bubble

B. P. Wakker, B. D. Savage, K. R. Sembach, P. Richter

We present FUSE observations of OVI absorption in a sample of 100 extragalactic targets and 2 distant halo stars. We describe the details of the calibration, alignment in velocity, continuum fitting, and manner in which contaminants were removed (Galactic H2, absorption intrinsic to the background target and intergalactic Ly-beta lines). We searched for OVI

M. G. Olsson

An efficient classification of light quark meson states is discussed based on the dominance of angular and radial quark excitation. A synthesis of Regge and quark dynamics allows a natural unification of light quark-antiquark spectroscopies and indicates the states that fall outside this category such as molecules, hybrids, and glueballs.

P. A. Price, S. R. Kulkarni, E. Berger, D. W. Fox

We present the discovery of GRB 020405 made with the Inter-Planetary Network (IPN). With a duration of 60 s, the burst appears to be a typical long duration event. We observed the 75-square acrminute IPN error region with the Mount Stromlo Observatory's 50-inch robotic telescope and discovered a transient source which subsequently decayed and was also associ

Yueheng Lan, Nicolas Garnier, Predrag Cvitanovic

We reformulate the one-dimensional complex Ginzburg-Landau equation as a fourth order ordinary differential equation in order to find stationary spatially-periodic solutions. Using this formalism, we prove the existence and stability of stationary modulated-amplitude wave solutions. Approximate analytic expressions and a comparison with numerics are given.

Jacques L. Rubin

A connection between creation of toroidal moments and breaking of the relativistic crystalline group associated to a given crystal, is presented in this paper. Indeed, if magnetoelectric effects exist, the interaction between electrons and elementary magnetic cells appears in such a way that the resulting local polarization and magnetization break the local

Fabio Cecconi, A. Puglisi, Umberto Marini Bettolo Marconi, Angelo Vulpiani

We study the behavior of two particles moving in a bistable potential, colliding inelastically with each other and driven by a stochastic heat bath. The system has the tendency to clusterize, placing the particles in the same well at low drivings, and to fill all of the available space at high temperatures. We show that the hopping over the potential barrier

G. W. Bennett

A higher precision measurement of the anomalous g value, a_mu = (g-2)/2, for the positive muon has been made at the Brookhaven Alternating Gradient Synchrotron, based on data collected in the year 2000. The result a_{mu^+} = 11 659 204(7)(5) times 10^{-10} (0.7 ppm) is in good agreement with previous measurements and has an error about one half that of the c

Subhabrata Majumdar, Joseph J. Mohr

We examine the prospects for measuring the dark energy equation of state parameter w within the context of the still uncertain redshift evolution of galaxy cluster structure. We show that for a particular X-ray survey (SZE survey) the constraints on w degrade by roughly a factor of 3 (factor of 2) when one accounts for the possibility of non--standard cluste

J. Ahrens, X. Bai, G. Barouch, S. W. Barwick

This paper describes the search for astronomical sources of high-energy neutrinos using the AMANDA-B10 detector, an array of 302 photomultiplier tubes, used for the detection of Cherenkov light from upward traveling neutrino-induced muons, buried deep in ice at the South Pole. The absolute pointing accuracy and angular resolution were studied by using coinci

E. Collin, W. Bailey, P. Fozooni, P. G. Frayne

We present measurements of the resonant microwave excitation of the Rydberg energy levels of surface state electrons on superfluid helium. The temperature dependent linewidth agrees well with theoretical predictions and is very small below 300 mK. Absorption saturation and power broadening were observed as the fraction of electrons in the first excited state

Yen-Ting Lin, Joseph J. Mohr

We explore the cosmological implications of 7 deep survey fields observed at the Berkeley-Illinois-Maryland Association (BIMA) Array with 30 GHz receivers. These observations probe the Cosmic Microwave Background anisotropy on scales corresponding to l=5500, and an earlier analysis of these data detected no galaxy clusters. We use numerical cluster simulatio

Andrew Gould

Using a reduced proper motion discriminator, I obtain a sample of 4588 subdwarfs from the Revised NLTT Catalog of Salim & Gould. The ample statistics and low contamination permit much more precise determinations of halo parameters than has previously been possible. The stellar halo is not moving with respect to the Local Standard of Rest (LSR) in either the

E. Levin, M. Lublinsky

The process of single diffractive dissociation off nuclei is considered on a basis of solutions to the nonlinear evolution equation. The relevant saturation scales $Q_{s A}^D(x,x_0)$ are determined and their dependences on Bjorken $x$, atomic number $A$, and minimal rapidity gap $Y_0\equiv \ln 1/x_0$ are investigated. The solutions are shown to posses the ge

Edward A. Baltz, P. Gondolo

The new measurement of the anomalous magnetic moment of the muon by the Brookhaven AGS experiment 821 again shows a discrepancy with the Standard Model value. We investigate the consequences of these new data for neutralino dark matter, updating and extending our previous work [E. A. Baltz and P. Gondolo, Phys. Rev. Lett. 86, 5004 (2001)]. The measurement ex

R. Raussendorf, H. J. Briegel

The one-way quantum computer (QCc) is a universal scheme of quantum computation consisting only of one-qubit measurements on a particular entangled multi-qubit state, the cluster state. The computational model underlying the QCc is different from the quantum logic network model and it is based on different constituents. It has no quantum register and does no

R. Kuchimanchi, R. N. Mohapatra

After some preliminary arguments suggesting that neutrino mixings with inverted mass pattern may be easier to understand within the framework of a local horizontal symmetry SU(2)_H acting on leptons, we construct a specific extension of the minimal supersymmetric standard model that implements the idea and analyze its predictions. We show that the horizontal

Jaroslaw Zalesny

The propagation of photon in a dielectric may be described with the help of the scalar and vector potentials of the medium. The main novelty of the paper is that the concept of the vector potential (which is connected with the velocity of the medium) can be extended to relativistic velocities of the medium. The position-dependent photon wave function was use

W. S. Carvalho, A. S. de Castro, A. C. B. Antunes

The SU(3)-flavor symmetry breaking and the quark-antiquark annihilation mechanism are taken into account for describing the singlet-octet mixing for several nonets assigned by Particle Data Group(PDG). This task is approached with the mass matrix formalism.

E. Aprile, E. A. Baltz, A. Curioni, K-L. Giboni

XENON is a novel liquid xenon experiment concept for a sensitive dark matter search using a 1-tonne active target, distributed in an array of ten independent time projection chambers. The design relies on the simultaneous detection of ionization and scintillation signals in liquid xenon, with the goal of extracting as much information as possible on an event

Nguyen Que Huong, Joseph L. Birman

A model is proposed to study the hybrid exciton in a quantum dot-dendrimer systems. The semiconductor organic hybrid exciton is studied using a "real space" Green's function method and a diagrammatic technique. The energy of the hybrid exciton as well as the Green function matrix elements have been calculated for different quantum dot-dendrimer systems, and

R. E. Smith, J. A. Peacock, A. Jenkins, S. D. M. White

We present the results of a large library of cosmological N-body simulations, using power-law initial spectra. The nonlinear evolution of the matter power spectra is compared with the predictions of existing analytic scaling formulae based on the work of Hamilton et al. The scaling approach has assumed that highly nonlinear structures obey `stable clustering

Vassil Kanev

We prove that the moduli spaces A_3(D) of polarized abelian threefolds with polarizations of types D=(1,1,2), (1,2,2), (1,1,3) or (1,3,3) are unirational. The result is based on the study of families of simple coverings of elliptic curves of degree 2 or 3 and on the study of the corresponding period mappings associated with holomorphic differentials with tra

Paul B. Slater

In a previous study (quant-ph/9911058), several remarkably simple exact results were found, in certain specialized m-dimensional scenarios (m<5), for the a priori probability that a pair of qubits is unentangled/separable. The measure used was the volume element of the Bures metric (identically one-fourth the statistical distinguishability [SD] metric). Here

S. A. Kulagin

We discuss the impact of nuclear effects on the higher twist terms using a particular example of the structure function xF_3 as extracted from a QCD fit to neutrino deep inelastic data on a heavy nucleus target.

Fred Cooper, Chung-Wen Kao, Gouranga C. Nayak

Using the Schwinger-Keldysh closed time path integral formalism we show that the magnetic screening mass in QED and QCD at one loop level is non-zero as long as the single particle distribution function f(\vec{k}) is non-isotropic, {i.e.} it depends on the direction of the momentum. For isotropic distribution functions such as those corresponding to thermal

R. E. Kastner

A relation is obtained between weak values of quantum observables and the consistency criterion for histories of quantum events. It is shown that ``strange'' weak values for projection operators (such as values less than zero) always correspond to inconsistent families of histories. It is argued that using the ABL rule to obtain probabilities for counterfact

Stoytcho Yazadjiev, Ventseslav Rizov

We report on a new two-parameter class of cosmological solutions to the Einstein-Maxwell equations. The solutions have everywhere regular curvature invariants. We prove that the solutions are geodesically complete and globally hyperbolic.

George Svetlichny

A physical theory of experiments carried out in a space-time region can accommodate a detector localized in another space-like separated region, in three, not necessarily exclusive, ways: 1) the detector formally collapses physical states across space-like separations, 2) the detector enables superluminal signals, and 3) the theory becomes logically inconsis

Bertrand Duplantier

We derive, from conformal invariance and quantum gravity, the multifractal spectrum f(alpha,c) of the harmonic measure (or electrostatic potential, or diffusion field) near any conformally invariant fractal in two dimensions, corresponding to a conformal field theory of central charge c. It gives the Hausdorff dimension of the set of boundary points where th

M. H. S. Amin

We present a non-equilibrium quasiclassical formalism suitable for studying linear response ac properties of Josephson junctions. The non-equilibrium self-consistency equations are satisfied, to very good accuracy, already in zeroth iteration. We use the formalism to study ac Josephson effect in a ballistic superconducting point contact. The real and imagina

Ailin Zhang, T. G. Steele

Two mechanisms for the $\pi_1$ ($J^{PC}=1^{-+}$) hybrid meson decay processes $\pi_1\to\eta\pi,\eta'\pi$ are investigated. These mechanisms are applied to $\phi\to\eta\gamma,\eta'\gamma$ and $J/\psi\to\eta\gamma,\eta'\gamma$ decays to illustrate the validity of the decay mechanisms and to obtain independent information on the coupling of $\eta,\eta'$ to quar

Gianfranco Brunetti

In the framework of the study of extragalactic radio sources, we will focus on the importance of the spatial resolution at different wavelengths, and of the combination of observations at different frequency bands. In particular, a substantial step forward in this field is now provided by the new generation X-ray telescopes which are able to image radio sour

D0 collaboration, V. M. Abazov

We report the first search for supersymmetric particles via s-channel production and decay of smuons or muon sneutrinos at hadronic colliders. The data for the two-muon and two-jets final states were collected by the DO experiment, and correspond to an integrated luminosity of 94 +/- 5 pb^{-1}. Assuming that R-parity is violated via the single coupling lambd

A. J. Buchmann

A quark model relation between the neutron charge form factor and the N->Delta charge quadrupole form factor is used to predict the C2/M1 ratio in the N->Delta transition from the elastic neutron form factor data. Excellent agreement with the electro-pionproduction data is found, indicating the validity of the suggested relation. The implication of the negat

J. F. Basson, P. Alexander

We have performed 3D hydrodynamical simulations of FR-II radio sources in beta-profile cooling-flow clusters. The effects of cooling of the cluster gas were incorporated into a modified version of the ZEUS-MP code. The simulations followed not only the active phase of the radio source, but also the long term behaviour for up to 2 Gyr after the jets of the ra

M. Ladrem, A. Ait-El-Djoudi, G. Yezza

We study the finite-size effects on the deconfinement phase transition (DPT) of hot and / or dense hadronic matter, using a simple thermodynamic model based on the assumption of coexistence of confined and deconfined phases in a finite volume, with the two-phases matter Equations of State. For the QGP, we consider a partition function (PF) with the exact col

Robin Stinchcombe, Martin Depken

A diffusion-deposition model for glassy dynamics in compacting granular systems is treated by time scaling and by a method that provides the exact asymptotic (long time) behavior. The results include Vogel-Fulcher dependence of rates on density, inverse logarithmic time decay of densities, exponential distribution of decay times and broadening of noise spect

Dayton L. Jones, Ann E. Wehrle

We have used the VLBA to produce a high dynamic range image of the nucleus of NGC 6251 at 1.6 GHz and snapshot images at 5.0, 8.4, and 15.3 GHz to search for emission from a parsec-scale counterjet. Previous VLBI images at 1.6 GHz have set a lower limit for the jet/counterjet brightness ratio near the core at about 80:1, which is larger than expected given t

V. NguyenKhac, K. NguyenVan

We give a geometric characterization of extremal sets in ell_p spaces that generalizes our previous result for such sets in Hilbert spaces.

O. Bertolami, L. Guisado

A model for a noncommutative scalar field coupled to gravity is proposed via an extension of the Moyal product. It is shown that there are solutions compatible with homogeneity and isotropy to first non-trivial order in the perturbation of the star-product, with the gravity sector described by a flat Robertson-Walker metric. We show that in the slow-roll reg

Alexandre Kurth, Dirk Tasche

This paper presents analytical solutions to the problem of how to calculate sensible VaR (Value-at-Risk) and ES (Expected Shortfall) contributions in the CreditRisk+ methodology. Via the ES contributions, ES itself can be exactly computed in finitely many steps. The methods are illustrated by numerical examples.

Y. B. Band, M. Sokuler

We present results of calculations on Bose-Einstein condensed $^{87}$Rb atoms subjected to a moving standing-wave light-potential of the form $V_L(z,t) = V_0(t) \cos(q z-\omega t)$. We calculate the mean-field dynamics (the order paramter) of the condensate and determine the resulting condensate momentum in the $z$ direction, $P_z(q,\omega,V_0,t_p)$, where $

D. -N. Peligrad, A. Dulcic, M. Mehring

The short wavelength cutoff has been introduced in the calculation of ac fluctuation conductivity of superconductors. It is shown that a finite cutoff leads to a breakdown of the scaling property in frequency and temperature. Also, it increases the phase phi of the complex conductivity (tan(phi)=sigma_2/sigma_1) beyond pi/4 at T_c. Detailed expressions conta

Juan Maldacena, Liat Maoz

We find a general class of pp-wave solutions of type IIB string theory such that the light cone gauge worldsheet lagrangian is that of an interacting massive field theory. When the light cone Lagrangian has (2,2) supersymmetry we can find backgrounds that lead to arbitrary superpotentials on the worldsheet. We consider situations with both flat and curved tr

P. Kanti, I. Olasagasti, K. Tamvakis

We consider branes embedded in spacetimes of codimension one and two, with a warped metric tensor for the subspace parallel to the brane. We study a variety of brane-world solutions arising by introducing a Schwarzschild-like black hole metric on the brane and we investigate the properties of the corresponding higher-dimensional spacetime. We demonstrate tha

Filipe Paccetti Correia

We show that the exact RG-flow equation introduced recently in hep-th/0207134 can be obtained in the sharp cut-off limit of the well-known ERGE. This can be expected from the fact that in this limit the new scale-dependent effective action coincides with the one which is usually considered.

Eugene Kanzieper

Exact solvability is claimed for nonlinear replica sigma models derived in the context of random matrix theories. Contrary to other approaches reported in the literature, the framework outlined does not rely on traditional "replica symmetry breaking" but rests on a previously unnoticed exact relation between replica partition functions and Painleve transcend

M. Frigerio, A. Yu. Smirnov

We reconstruct the neutrino mass matrix in flavor basis, in the case of inverted mass hierarchy (ordering), using all available experimental data on neutrino masses and oscillations. We analyze the dependence of the matrix elements m_{alpha beta} on the CP violating Dirac, delta, and Majorana, rho and sigma, phases, for different values of the absolute mass

Christopher P. Bidinosti, Jamal Choukeife, Pierre-Jean Nacher, Geneviève Tastevin

We present NMR measurements of the diffusion of hyperpolarized helium-3 in the human lung performed at fields much lower than those of conventional MRI scanners. The measurements were made on standing subjects using homebuilt apparatus operating at 3 mT. Oxygen-limited transverse relaxation (T2 up to 15-35 s) could be measured in-vivo. Accurate global diffus

E. E. Kolomeitsev, D. N. Voskresensky

Regular sequences of narrow peaks have been observed in the missing mass spectra in the reactions pp --> p pi^+ X and pd --> ppX_1 below pion-production threshold. They are interpreted in the literature as manifestations of supernarrow light dibaryons, or nucleon resonances, or light pions forming resonance states with the nucleon in its ground state. We dis

Debashish Goswami, A. O. Kuku

Given an action of a discrete quantum group (in the sense of Van Daele, Kustermans and Effros-Ruan) ${\cal A}$ on a $C^*$-algebra ${\cal C}$, satisfying some regularity assumptions resembling the proper $\Gamma$-compact action for a classical discrete group $\Gamma$ on some space, we are able to construct canonical maps $\mu^i_r$ (\$\mu_i$ respectively) ($i=

E. E. Kolomeitsev, N. Kaiser, W. Weise

We present and discuss a systematic calculation, based on two-loop chiral perturbation theory, of the pion-nuclear s-wave optical potential. A proper treatment of the explicit energy dependence of the off-shell pion self-energy together with (electromagnetic) gauge invariance of the Klein-Gordon equation turns out to be crucial. Accurate data for the binding

P. V. Tytarenko, R. J. R. Williams, S. A. E. G. Falle

We analyse the stability of a magnetized medium consisting of a neutral fluid and a fluid of charged particles, coupled to each other through a drag force and exposed to differential body forces (for example, as the result of radiation forces on one phase). We consider a uniform equilibrium and simple model input physics, but do not arbitrarily restrict the

P. Bergeron, S. K. Leggett

A detailed analysis of the very cool white dwarfs SDSS 1337+00 and LHS 3250 is presented. Model atmosphere calculations with improved collision-induced absorptions by molecular hydrogen indicate that a pure hydrogen composition can be ruled out, and that the strong infrared absorption observed in these cool stars is better explained in terms of collisions of

C. Broadbent, G. Hovhannisyan, M. Clayton, J. Peatross

We solve the problem addressed by Landau and Lifshitz in 1958, and Oughstun and Sherman of determining the dynamical losses in a purely dissipative dielectric media. We develop concrete notions of macroscopic free energy and losses as energy which is reversible and irreversible, respectively, in the medium-field interaction. We define the reversible and irre

V. E. Barnard, A. W. Blain, N. R. Tanvir, P. Natarajan

We present the results of a search for submillimetre-luminous host galaxies of optically dark gamma-ray bursts (GRBs) using the Submillimetre Common-User Bolometer Array (SCUBA) on the James Clerk Maxwell Telescope (JCMT). We made photometry measurements of the 850-micron flux at the location of four `dark bursts', which are those with no detected optical af

Maciej Mroczkowski

In the classical knot theory there is a well-known notion of descending diagram. From an arbitrary diagram one can easily obtain, by some crossing changes, a descending diagram which is a diagram of the unknot or unlink. In this paper the notion of descending diagram for knots and links in the real space is extended to the case of nonoriented knots and links

Ed Copeland, James Gray, Andre Lukas, David Skinner

Under certain conditions some solutions to five-dimensional heterotic M-theory can be accurately described by the four-dimensional action of the theory - they have a four-dimensional limit. We consider the connection between solutions of four and five-dimensional heterotic M-theory when moving five-branes are present in the bulk. We begin by describing how t

E. H. Martins Ferreira, M. C. Nemes

We derive the tunneling rate for paramagnetic molecules in the context of a collective spin model. By means of path integral methods an analytical expression is derived. Given the very large spins in question (s ~ 3000 hbar), the observation of magnetization changes due to pure unitary tunnel effects is unlikely.

Martin Olbrich

This paper contains a thorough investigation of invariant distributions supported on limit sets of discrete groups acting convex cocompactly on symmetric spaces of negative curvature. It can be considered as a continuation of math.DG/9810146. Based on this investigation we provide proofs of the Hodge theoretic results for the cohomology of real hyperbolic ma

Juergen Schmidhuber

We present a novel, general, optimally fast, incremental way of searching for a universal algorithm that solves each task in a sequence of tasks. The Optimal Ordered Problem Solver (OOPS) continually organizes and exploits previously found solutions to earlier tasks, efficiently searching not only the space of domain-specific algorithms, but also the space o

Bruce D. Scott

The competition between drift wave and interchange physics in general E-cross-B drift turbulence is studied with computations in three dimensional tokamak flux tube geometry. For a given set of background scales, the parameter space can be covered by the plasma beta and drift wave collisionality. At large enough plasma beta the turbulence breaks out into ide

Ph. Brax, D. A. Steer

We argue that bouncing branes occur naturally when there is more than one extra-dimension. We consider three-branes embedded in space-times with a horizon and an isometry group SO(6). As soon as the brane angular momentum is large enough, a repulsive barrier prevents the branes from reaching the horizon. We illustrate this phenomenon with the case of D3-bran

B. Aslan, G. Zech

Various distribution free goodness-of-fit test procedures have been extracted from literature. We present two new binning free tests, the univariate three-region-test and the multivariate energy test. The power of the selected tests with respect to different slowly varying distortions of experimental distributions are investigated. None of the tests is optim

V. A. Khoze, M. G. Ryskin, W. J. Stirling, P. H. Williams

We study central Z-boson production accompanied by rapidity gaps on either side as a way to gauge Higgs weak boson fusion production at the LHC. We analyse the possible backgrounds for the bb-decay mode and show that these can be substantially reduced. Special attention is paid to the evaluation of the gap survival factor, which is the major source of theore

Jerzy Kowalski-Glikman

We show that Doubly Special Relativity (DSR) can be viewed as a theory with energy-momentum space being the four dimensional de Sitter space. Different formulations (bases) of the DSR theory considered so far can be therefore understood as different coordinate systems on this space. The emerging geometrical picture makes it possible to understand the univers

Jaume Guasch, Wolfgang Hollik, Joan Sola

We present a definition of an on-shell renormalization scheme for the sfermion and chargino-neutralino sector of the Minimal Supersymmetric Standard Model (MSSM). Then, apply this renormalization framework to the interaction between charginos/neutralinos and sfermions. A kind of universal corrections is identified, which allow to define effective chargino/ne

I. Waddington, R. A. Windhorst, S. H. Cohen, J. S. Dunlop

Deep spectroscopy of the two mJy radio galaxies LBDS 53W069 and 53W091 has previously shown them to have old (>3 Gyr) stellar populations at z=1.5. Here we present the results of HST observations of these galaxies. 53W069 has an r^1/4 profile in both the F814W & F110W data with an effective radius of 0.30 arcsec (2.7 kpc). The restframe U-B colour gradient r

Neal A. Miller, Frazer N. Owen

(Abridged) We have used optical spectroscopy to investigate the radio- selected active galaxy populations in a sample of 20 nearby Abell clusters. The spectra were used to characterize the galaxies as AGN or galaxies forming stars at rates comparable to or greater than the Milky Way. A significant population of star forming galaxies with large amounts of nuc

T. Obata, M. Kubota

The vortex pair phase field is calculated, through a solution of the Laplace equation, for a superfluid film adsorbed on the surface of a model 3D connected porous medium. A number of different vortex-antivortex pair configurations are considered as functions of the porosity or an aspect ratio of the model porous structure. The calculated results give the en

Patrick Erik Bradley

Formulae for the number of branch points of one-dimensional orbifolds defined over a non-archimedean local field and uniformisable by discrete projective linear groups are given. They depend only on the uniformising group. The method of equivariant pasting reveals the possible relative position of the branch points.

O. Bertolami, M. Tajmar

A scientific analysis of the conditions under which gravity could be controlled and the implications that an hypothetical manipulation of gravity would have for known schemes of space propulsion have been the scope of a recent study carried out for the European Space Agency. The underlying fundamental physical principles of known theories of gravity were ana

Evgeny Epelbaum, Ulf-G. Meißner, Walter Glöckle

We investigate the behaviour of the nuclear forces as a function of the light quark masses (or, equivalently, pion mass) in the framework of chiral effective field theory at next-to-leading order. The nucleon-nucleon force is described in terms of one- and two-pion exchange and local short distance operators, which depend explicitly and implicitly on the qua

Paul S. Muhly, Baruch Solel

We study conjugacy invariants for completely positive maps that are inspired by the concept of curvature introduced for commuting d-tuples of contractions by Arveson

Y. B. Band, I. Towers, B. Malomed

We present semiclassical descriptions of Bose-Einstein condensates for configurations with spatial symmetry, e.g., cylindrical symmetry, and without any symmetry. The description of the cylindrical case is quasi-one-dimensional (Q1D), in the sense that one only needs to solve an effective 1D nonlinear Schrodinger equation, but the solution incorporates corre

Fabio Enrique Brochero Martinez

Let G a group of germs of analytic diffeomorphisms in (C^2,0). We find some remarkable properties supposing that G is finite, linearizable, abelian nilpotent and solvable. In particular, if the group is abelian and has a generic dicritic diffeomorphisms, then the group is a subgroup of a 1-parametric group. In addition, we study the topological behaviour of

Sitabhra Sinha, David J. Christini

Reentrant waves propagating in a ring or annulus of excitable media model is the basic mechanism underlying a major class of irregular cardiac rhythms known as anatomical reentry. Such reentrant waves are terminated by rapid electrical stimulation (pacing) from an implantable device. Because the mechanisms of such termination are poorly understood, we study

V. N. Strocov, P. O. Nilsson, A. Augustsson, T. Schmitt

The local electronic structure of N atoms in a diluted GaAs1-xNx (x=3%) alloy, in view of applications in optoelectronics, is determined for the first time using soft-X-ray absorption (SXA) and emission (SXE). Deviations from crystalline GaN, in particular in the conduction band, are dramatic. Employing the orbital character and elemental specificity of the

S. Krompiewski

Effect of contact interfaces, between metallic single-wall carbon nanotubes (SWCNT) and external electrodes made also of nanotubes, on the electrical conductance is studied. A tight-binding model with both diagonal and off-diagonal disorder, a recursive Green function technique as well as the Landauer formalism are used. The studies are carried out within th

Marco Cecchini, Vincenzo Piazza, Fabio Beltram, Marco Lazzarino

Planar light-emitting diodes (LEDs) fabricated within a single high-mobility quantum well are demonstrated. Our approach leads to a dramatic reduction of radiative lifetime and junction area with respect to conventional vertical LEDs, promising very high-frequency device operation. Devices were fabricated by UV lithography and wet chemical etching starting f

M. Gomez-Reino, I. Zavala

We consider the interactions between Dp-branes intersecting at an arbitrary number of angles in the context of type II string theory. For cosmology purposes we concentrate in the theory on R^{3,1} x T^6. Interpreting the distance between the branes as the inflaton field, the branes can intersect at most at two angles on the compact space. If the configuratio

R. Oppermann, D. Sherrington

Models with range-free frustrated Ising spin- and Hubbard interaction are treated exactly by means of the discrete time slicing method. Critical and tricritical points, correlations, and the fermion propagator, are derived as a function of temperature T, chemical potential \mu, Hubbard coupling U, and spin glass energy J. The phase diagram is obtained. Repli

Mathieu Taillefumier, Delphine Cabaret, Anne-Marie Flank, Francesco Mauri

We present a reciprocal-space pseudopotential scheme for calculating X-ray absorption near-edge structure (XANES) spectra. The scheme incorporates a recursive method to compute absorption cross section as a continued fraction. The continued fraction formulation of absorption is advantageous in that it permits the treatment of core-hole interaction through la

Qiang Li, Li Gang Jin, Chong Sheng Li

We calculate the Yukawa corrections of order ${\cal O}(\alpha_{ew}m_{t(b)}^2/m_W^2)$, ${\cal O}(\alpha_{ew}m_{t(b)}^3/m_W^3)$ and ${\cal O}(\alpha_{ew}m_{t(b)}^4/m_W^4)$ to the widths of the decays $\tilde t_2\to \tilde t_1 + (h^0,H^0,A^0)$ in the Minimal Supersymmetric Standard Model, and perform a detailed numerical analysis. We also compare the results wi

H. W. Schumacher, C. Chappert, R. C. Sousa, P. P. Freitas

We demonstrate a quasi ballistic switching of the magnetization in a microscopic mag-neto resistive memory cell. By means of time resolved magneto transport we follow the large angle precession of the free layer magnetization of a spin valve cell upon applica-tion of transverse magnetic field pulses. Stopping the field pulse after a 180 degree precession rot

Paolo Nason

Recent progress in Heavy Flavour Production phenomenology are discussed. In particular, the long-standing discrepancy of the Tevatron b production data is considered. It is shown that a better use of e^+e^- data in constraining the effect of fragmentation reduces the discrepancy considerably.

Jean El Bachir Mendy, Jan Govaerts

Given the most general Lorentz invariant four-fermion effective interaction possible for two neutrinos and two charged fermions, whether quarks or leptons, all possible 2-to-2 processes involving two neutrinos, whether Dirac or Majorana ones, and two charged fermions are considered. Explicit and convenient expressions are given for the associated differentia