December 2001 arXiv papers — page 12

A. Sciarrino

Using crystal basis, in the space of symmetric irreducible representations, we explicitly write invertible deforming functionals between the q-deformed universal enveloping algebra and the Lie algebras sl(n) and sp(2n).For sl(2) we obtain the Curtright-Zachos map.

Luc Lemaire, John C. Wood

We show that any Jacobi field along a harmonic map from the 2-sphere to the complex projective plane is integrable (i.e., is tangent to a smooth variation through harmonic maps). This provides one of the few known answers to this problem of integrability, which was raised in different contexts of geometry and analysis. It implies that the Jacobi fields form

Ahmed Abbes, Takeshi Saito

Classically the ramification filtration of the Galois group of a complete discrete valuation field is defined in the case where the residue field is perfect. In this paper, we define without any assumption on the residue field, two ramification filtrations and study some of their properties.

Fahd A. A. Al-Agl, Ronald Brown, Richard Steiner

We show the equivalence of two kinds of strict multiple category, namely the well known globular omega-categories, and the cubical omega-categories with connections.

J. R. Hiller, S. S. Pinsky, U. Trittmann

A supersymmetric formulation of a three-dimensional SYM-Chern-Simons theory using light-cone quantization is presented, and the supercharges are calculated in light-cone gauge. The theory is dimensionally reduced by requiring all fields to be independent of the transverse dimension. The result is a non-trivial two-dimensional supersymmetric theory with an ad

J. L. Acebal

One shows here the existence of solutions to the Callan-Symanzik equation for the non-Abelian SU(2) Chern-Simons-matter model which exhibits asymptotic conformal invariance to every order in perturbative theory. The conformal symmetry in the classical domain is shown to hold by means of a local criteria based on the trace of the energy-momentum tensor. By us

P. Bain

In the first part of this article, we find fractional D3-branes supergravity solutions on orientifolded C^2/Z_2 orbifolds of type IIB string theory. The one-loop corrected gauge couplings for the symplectic or orthogonal groups living on the D-branes are reproduced on the world-volume of probes. In the second part of the paper, we construct a D3-brane soluti

Roberto Casalbuoni

In this paper we extend the idea of integration to generic algebras. In particular we concentrate over a class of algebras, that we will call self-conjugated, having the property of possessing equivalent right and left multiplication algebras. In this case it is always possible to define an integral sharing many of the properties of the usual integral. For i

G. S. Danilov

The unitarity equations for the boson interaction amplitudes in the superstring theory are used to calculate the interaction amplitudes including the Ramond states, which are 10-fermion and Ramond bosons. The n-loop, 4-point amplitude with two massless Neveu-Schwarz bosons and two massless Ramond states is obtained explicitly. It is shown that, in addition,

L. Laperashvili, D. A. Ryzhikh

In the present paper we demonstrate the possibility of the [SUSY(5)]^3 SUSY unification at the energy scale $μ_{GUT}\approx 10^{18.3} GeV$ with the value of GUT inverse finestructure constant $α_{GUT}^{-1}\approx 34.4$, which is very close to its critical value $α_{5, crit}^{-1}\approx 34.0$, existing at the Planck scale.

Lisa M. Dyson, Laur Jarv, Clifford V. Johnson

We present some results of studying certain axially symmetric supergravity geometries corresponding to a distribution of BPS D6-branes wrapped on K3, obtained as extremal limits of a rotating solution. The geometry's unphysical regions resulting from the wrapping can be repaired by the enhancon mechanism, with the result that there are two nested enhanco

A. J. M. Medved

In a recent paper (hep-th/0111091), the near-extremal thermodynamics of a 4-dimensional Reissner-Nordstrom black hole had been considered. In the current letter, we extend this prior treatment to the more general case of a spherically symmetric, charged black hole of arbitrary dimensionality. After summarizing the earlier work, we demonstrate a duality that

M. Fontannaz, J. Ph. Guillet, G. Heinrich

We study the production of an isolated large p_T photon as well as the production of an isolated prompt photon plus a jet in e^+e^- collisions. Our results are obtained by a NLO Monte Carlo program of partonic event generator type. We discuss the possibilities to constrain the parton densities in the real photon and compare to preliminary OPAL data.

William A. Bardeen

I discuss methods based on the large Nc expansion to study nonperturbative aspects of quantum chromodynamics, the theory of the strong force. I apply these methods to the analysis of weak decay processes and the nonperturbative computation of the weak matrix elements needed for a complete evaluation of these decays in the Standard Model of elementary particl

M. Consoli

Due to the peculiar nature of the underlying medium, density fluctuations in a `Higgs condensate' are predicted to propagate for infinitely long wavelengths with a group velocity $c_s\to \infty $. On the other hand, for any large but finite $c_s$ there is a weak, attractive $1/r$ potential of strength ${{1}\over{c^2_s}}$ and the energy spectrum deviates

P. J. Mulders

In these lectures I want to discuss how the structure functions in deep inelastic scattering relate to quark and gluon correlation functions. In particular we will consider the issue of intrinsic transverse momenta of quarks, which becomes important in processes like 1-particle inclusive leptoproduction. Some examples of cross sections and asymmetries, in pa

T. A. Lahde, D. O. Riska

The $π$ and $ππ$ decay widths of the excited charm mesons are calculated using a Hamiltonian model within the framework of the covariant Blankenbecler-Sugar equation. The pion-light constituent quark coupling is described by the chiral pseudovector Lagrangian.

S. Kumano

Polarized flavor asymmetry Delta u-bar/Delta d-bar is investigated in a meson-cloud model. A polarized nucleon splits into a rho meson and a baryon, then the polarized rho meson interacts with the virtual photon. Because of the difference between the longitudinally polarized distributions Delta u-bar and Delta d-bar in rho, the polarized flavor asymmetry is

Chia-Hung V. Chang, Wei-Shu Hou

We study B meson decays to two charmless baryons in the diquark model, including strong and electroweak penguins as well as the tree operators. It is shown that penguin operators can enhance $\bar{B} \to \Bb_s \bar{\Bb}$ considerably, but affect $\bar{B} \to \Bb_1 \bar{\Bb}_2$ only slightly, where $\Bb_{(1,2)}$ and $\Bb_s$ are non-strange and strange baryons

S. M. Bilenky, D. Nicolo, S. T. Petcov

Results of a new analysis of the CHOOZ data, performed in the framework of three-neutrino mixing, are presented. Both the cases of normal and inverted neutrino mass hierarchy are considered. The parameters characterizing the solar neutrino oscillations, $Δm^2_{\odot}$ and $θ_{\odot}$, are assumed to lie in the region of the large mixing angle (LMA) MSW solut

Csaba Csaki, Nemanja Kaloper, John Terning

We have recently proposed a mechanism of photon-axion oscillations as a way of rendering supernovae dimmer without cosmic acceleration. Subsequently, it has been argued that the intergalactic plasma may interfere adversely with this mechanism by rendering the oscillations energy dependent. Here we show that this energy dependence is extremely sensitive to th

L. V. Laperashvili, D. A. Ryzhikh

The phase transition "Coulomb-confinement" in the U(1) regularized gauge theory is considered in the framework of dual Abelian Higgs model of scalar monopoles (shortly: Higgs monopole model). The effective potential analogous to the Coleman-Weinberg's one, improved by the renormalization group equation, is constructed, using beta-functions in the

P. O. Bowman, U. M. Heller, A. G. Williams

Studies of gauge dependent quantities are afflicted with Gribov copies, but Laplacian gauge fixing provides one possible solution to this problem. We present results for the lattice quark propagator in both Landau and Laplacian gauges using standard and improved staggered quark actions. The standard Kogut-Susskind action has errors of \oa{2} while the improv

Steven Gottlieb

Small Beowulf clusters can effectively serve as personal or group supercomputers. In such an environment, a cluster can be optimally designed for a specific problem (or a small set of codes). We discuss how theoretical analysis of the code and benchmarking on similar hardware lead to optimal systems.

S. Catterall, S. Karamov

We describe a Fourier Accelerated Hybrid Monte Carlo algorithm suitable for dynamical fermion simulations of non-gauge models. We test the algorithm in supersymmetric quantum mechanics viewed as a one-dimensional Euclidean lattice field theory. We find dramatic reductions in the autocorrelation time of the algorithm in comparison to standard HMC.

Colin Morningstar

A new method of extracting the low-lying energy spectrum from Monte Carlo estimates of Euclidean-space correlation functions which incorporates Bayesian inference is described and tested. The procedure fully exploits the information present in the correlation functions at small temporal separations and uses this information in a way consistent with fundament

Katsuya Ishiguro, Tsuneo Suzuki, Tateaki Yazawa

Effective monopole action at finite temperature in SU(2) gluodynamics is studied on anisotropic lattices. Using an inverse Monte-Carlo method and the blockspin transformation for space directions, we determine 4-dimensional effective monopole action at finite temperature. We get an almost perfect action in the continuum limit under the assumption that the ac

Derek B. Leinweber

A new intuitive method for the rapid calculation of the leading nonanalytic behavior of hadronic observables in quenched chiral perturbation theory is presented. After proving the technique in a consideration of baryon masses, the quenched magnetic moments of octet baryons are addressed. The technique provides a separation of magnetic moment contributions in

I. Ajinenko, S. Akimenko, G. Akopdzhanov, K. Belous

The decay K- -> pi0 e- nu has been studied using in-flight decays detected with "ISTRA+" setup operating at the 25 GeV negative secondary beam of the U-70 PS. About 130K events were used for the analysis. The lambda_+ parameter of the vector formfactor has been measured: lambda_+ = 0.0293 +- 0.0015(stat) +- 0.002(syst). The limits on the possible ten

Alan D. Rendall

Centre manifold theory is applied to some dynamical systems arising from spatially homogeneous cosmological models. Detailed information is obtained concerning the late-time behaviour of solutions of the Einstein equations of Bianchi type III with collisionless matter. In addition some statements in the literature on solutions of the Einstein equations coupl

John Quiroga H

A simplified Randall-Sundrum-like model in 6 dimensions is discussed. The extra two dimensions correspond to the cone. The effective four-dimensional scalar self-interacting theory is studied at one-loop level. The contributions due to 6-dimensional parameters in four-dimensional beta-functions appear. Using such beta-functions the one-loop effective potenti

Abhay Ashtekar

Over the last three years, a number of fundamental physical issues were addressed in loop quantum gravity. These include: A statistical mechanical derivation of the horizon entropy, encompassing astrophysically interesting black holes as well as cosmological horizons; a natural resolution of the big-bang singularity; the development of spin-foam models which

R. Brout

In the context of the two-fluid model introduced to tame the transplanckian problem of black hole physics, the inflaton field of the chaotic inflation scenario is identified with the fluctuation of the density of modes. Its mass comes about from the exchange of degrees of freedom between the two fluids.

Philippe Matherat, Marc-Thierry Jaekel

Concrete computing machines, either sequential or concurrent, rely on an intimate relation between computation and time. We recall the general characteristic properties of physical time and of present realizations of computing systems. We emphasize the role of computing interferences, i.e. the necessity to avoid them in order to give a causal implementation

M. Ishii, T. Fukui, Y. Furukawa, T. Nakatani

The beamline network system at SPring-8 consists of three LANs; a BL-LAN for beamline component control, a BL-USER-LAN for beamline experimental users and an OA-LAN for the information services. These LANs are interconnected by a firewall system. Since the network traffic and the number of beamlines have increased, we upgraded the backbone of BL-USER-LAN fro

A. Luedeke

The commissioning of the Swiss Light Source (SLS) started in Feb. 2000 with the Linac, continued in May 2000 with the booster synchrotron and by Dec. 2000 first light in the storage ring were produced. The first four beam lines had to be operational by August 2001. The thorough integration of all subsystems to the control system and a high level of automatio

M. W. C. Dharma-wardana, Francois Perrot

The equation of state and the shock Hugoniot of deuterium are calculated using a first-principles approach, for the conditions of the recent shock experiments. We use density functional theory within a classical mapping of the quantum fluids [ Phys. Rev. Letters, {\bf 84}, 959 (2000) ]. The calculated Hugoniot is close to the Path-Integral Monte Carlo (PIMC)

Morrel H. Cohen, Jorge Iniguez, J. B. Neaton

After summarizing the phenomenology of pressure amorphization (PA), we present a theory of PA based on the notion that one or more branches of the phonon spectrum soften and flatten with increasing pressure. The theory expresses the anharmonic dynamics of the flat branches in terms of local modes, represented by lattice Wannier functions, which are in turn u

J. -B. Fournier, P. Galatola

We determine the capillary attraction and equilibrium configurations of particles trapped at a liquid-fluid interface due to the pinning of their contact-line. We calculate analytically the asymptotic interaction energy between two particles and, numerically, the multi-body energy landscape for up to four contacting particles. Our results are consistent with

D. Reguera, P. Reimann, P. Hänggi, J. M. Rubí

We elucidate how the presence of noise may significantly interact with the synchronization mechanism of systems exhibiting frequency-locking. The response of these systems exhibits a rich variety of behaviors, such as resonances and anti-resonances which can be controlled by the intensity of noise. The transition between different locked regimes provokes the

S. Torquato, F. H. Stillinger

Hard-particle packings have served as useful starting points to study the structure of diverse systems such as liquids, living cells, granular media, glasses, and amorphous solids. Howard Reiss has played a major role in helping to illuminate our understanding of hard-particle systems, which still offer scientists many interesting conundrums. Jammed configur

Alejandro B. Kolton, Daniel Dominguez, Niels Gronbech-Jensen

We find mode-locking steps in simulated current-voltage characteristics of driven vortex lattices with {\it random} pinning when an applied ac-current is {\it perpendicular} to the dc-current. For low frequencies there is mode-locking only above a non-zero threshold ac force amplitude, while for large frequencies there is mode-locking for any small ac force.

Miguel Vazquez-Prada, Alvaro Gonzalez, Javier B. Gomez, Amalio F. Pacheco

In a spirit akin to the sandpile model of self-organized criticality, we present a simple statistical model of the cellular-automaton type which produces an avalanche spectrum similar to the characteristic-earthquake behavior of some seismic faults. This model, that has no parameter, is amenable to an algebraic description as a Markov Chain. This possibility

D. S. Dean, F. Ritort

The mean field theory of a spin glass with a specific form of nearest and next nearest neighbor interactions is investigated. Depending on the sign of the interaction matrix chosen we either find the continuous replica symmetry breaking seen in the Sherrington-Kirkpartick model or a one step solution similar to that found in structural glasses. Our results a

Diego A. R. Dalvit, Jacek Dziarmaga, Roberto Onofrio

We analyze the dynamics of a Bose-Einstein condensate undergoing a continuous dispersive imaging by using a Lindblad operator formalism. Continuous strong measurements drive the condensate out of the coherent state description assumed within the Gross-Pitaevskii mean-field approach. Continuous weak measurements allow instead to replace, for timescales short

Clécio C. de Souza Silva, Leonardo R. E. Cabral, J. Albino Aguiar

Vortices in a narrow superconducting strip with a square array of pinning sites are studied. The interactions of vortices with other vortices and with external sources (applied magnetic field and transport current) are calculated via a screened Coulomb model. The edge barrier is taken into account and shown to have an important role on the system dynamics. N

Agata Aleksiejuk, Janusz A. Holyst, Dietrich Stauffer

Ising spins put onto a Barabasi-Albert scale-free network show an effective phase transition from ferromagnetism to paramagnetism upon heating, with an effective critical temperature increasing as the logarithm of the system size. Starting with all spins up and upon equilibration pinning the few most-connected spins down nucleates the phase with most of the

Tomaso Aste, Tiziana Di Matteo, Enrico Galleani d'Agliano

The transmission of forces through a disordered granular system is studied by means of a geometrical-topological approach that reduces the granular packing into a set of layers. This layered structure constitutes the skeleton through which the force chains set up. Given the granular packing, and the region where the force is applied, such a skeleton is uniqu

X. S. Chen, V. Dohm

The singular part of the finite-size free energy density $f_s$ of the O($n$) symmetric $ϕ^4$ field theory is calculated for confined geometries of linear size L with periodic boundary conditions in the large-N limit and with Dirichlet boundary conditions in one-loop order. We find that both a sharp cutoff and a subleading long-range interaction cause a non-u

F. M. Peeters, B. J. Baelus

The nonlinear Ginzburg-Landau equations are solved numerically in order to investigate the vortex structure in thin superconducting disks of arbitrary shape. Depending on the size of the system and the strength of the applied magnetic field giant vortex, multi-vortex and a combination of both of them are found. The saddle points in the energy landscape are i

Vittorio Cataudella, Rosario Fazio

In this Letter we study the phase diagram and the approach to the equilibrium of Josephson junction arrays on a dice lattice for two different values of the magnetic frustration ($f=1/2,1/3$). In both cases the array unedrgoes a Berezinskii-Kosterlitz-Thouless like phase transition. For the fully frustrated array, $f=1/2$, we find evidence of a {\em glassy b

R. Fleischmann, T. Geisel

Recent experiments on symmetry-broken mesoscopic semiconductor structures have exhibited an amazing rectifying effect in the transverse current-voltage characteristics with promising prospects for future applications. We present a simple microscopic model, which takes into account the energy dependence of current-carrying modes and explains the rectifying ef

Sebastian Bouzat, Horacio S. Wio

We study a Brownian motor driven by a colored non Gaussian noise source with a $q$-dependent probability distribution, where $q$ is a parameter indicating the departure from Gaussianity. For $q=1$ the noise is Gaussian (Ornstein--Uhlenbeck), while, for $q>1$, the probability distribution falls like a power law. In the latter case, we find a marked enhancemen

Y. G. Cornelissens, F. M. Peeters

Patterned two-dimensional electron gas (2DEG) systems into micrometer Hall bars can be used as Hall magnetosensors to provide detailed information on the magnetic field distribution. In this way, ballistic Hall probes have already been studied and used successfully. Here, the response function of a Hall sensor is determined in the diffusive regime, which all

V. V. Flambaum, G. A. Stewart, G. J. Russell, J. Horvat

Hydrogenation of MgB_2 powder has lead to an increase in the superconducting temperature, as determined by ac susceptibility. Applied dc fields reduce the transition temperature in the same ratio as for the pure powder.

L. L. Chu, K. W. Yu

We have studied anomalous diffusion of a particle in a random medium in which the passage of the particle may modify the state of the visited sites. The simplicity of the dynamics allows analytic solution. Interesting propagation and organization behaviors will be reported.

S. J. Mitchell, Sanwu Wang, P. A. Rikvold

We investigate the static and dynamic behaviors of a Br adlayer electrochemically deposited onto single-crystal Ag(100) using an off-lattice model of the adlayer. Unlike previous studies using a lattice-gas model, the off-lattice model allows adparticles to be located at any position within a two-dimensional approximation to the substrate. Interactions with

M. Elvis, G. Risaliti, G. Zamorani

We use the integrated spectrum of the X-ray background and quasars Spectral Energy Distribution to derive the contribution of quasars to the energy output of the Universe. We find a lower limit for the energy from accretion onto black holes of 6%, of the total luminosity of the Universe and probably more, with 15% quite possible. Comparing these values with

Masahiro Takada, Hiroshi Ohno, Naoshi Sugiyama

The observed magnetic field of microgauss strength in clusters of galaxies should induce the Faraday rotation effect on the linearly polarized cosmic microwave background (CMB) radiation when the CMB radiation propagates through a cluster at low redshift. Employing the Press-Schechter prescription for the cluster abundance under the cold dark matter (CDM) sc

S. Turcotte, G. Bazan, J. Castor, R. Cavallo

The DJEHUTY project is an intensive effort at the Lawrence Livermore National Laboratory (LLNL) to produce a general purpose 3-D stellar structure and evolution code to study dynamic processes in whole stars.

T. Treu, R. Ellis, P. Trivedi, J. -P. Kneib

We describe the first results from a comprehensive study of the distant cluster Cl0024+1654 (z=0.39) based upon a pattern of 38 mosaiced HST-WFPC2 images extending to radii ~5Mpc. These are being analysed in conjunction with extensive spectroscopy conducted with the CFHT, WHT, and Keck Telescopes. The overall goal is to understand the morphological transform

Asantha Cooray

We discuss the correlation between late-time integrated Sachs-Wolfe (ISW) effect in the cosmic microwave background (CMB) temperature anisotropies and the large scale structure of the local universe. This correlation has been proposed and studied in the literature as a probe of the dark energy and its physical properties. We consider a variety of large scale

Alan P. Boss, George W. Wetherill, Nader Haghighipour

The existence of Uranus and Neptune presents severe difficulties for the core accretion model for the formation of ice giant planets. We suggest an alternative mechanism, namely disk instability leading to the formation of gas giant protoplanets, coagulation and settling of dust grains to form ice/rock cores at their centers, and photoevaporation of their ga

Claes Fransson, Cecilia Kozma

The nucleosynthesis and production of radioactive elements in SN 1987A are reviewed. Different methods for estimating the masses of 56Ni, 57Ni, and 44Ti are discussed, and we conclude that broad band photometry in combination with time-dependent models for the light curve gives the most reliable estimates.

D. Pierini, A. Majeed, T. A. Boroson, A. N. Witt

We obtained low-resolution, long-slit 5300--9100 A spectroscopy of NGC4826 (a nearby galaxy with an absorbing dust lane (DL) asymmetrically placed across its bulge, associated with several HII regions) with a slit encompassing its bulge, positioned across its nucleus. The wavelength-dependent effects of absorption and scattering by dust in the lane are evide

S. V. Marchenko, A. F. J. Moffat, W. D. Vacca, S. Cote

Some hot, massive, population-I Wolf-Rayet (WR) stars of the carbon subclass are known to be prolific dust-producers. How dust can form in such a hostile environment remains a mystery. Here we report the discovery of a relatively cool, extended, multi-arc dust envelope around the star WR112, most likely formed by wind-wind collision in a long-period binary s

I. Neill Reid

We consider the metallicities and kinematics of nearby stars known to have planetary-mass companions in the general context of the overall properties of the local Galactic Disk. We have used Stromgren photometry to determine abundances for both the extrasolar-planet host stars and for a volume-limited sample of 486 F, G and K stars selected from the Hipparco

F. Kupka, M. H. Montgomery

We present results of a fully non-local, compressible model of convection for A-star envelopes. This model quite naturally reproduces a variety of results from observations and numerical simulations which local models based on a mixing length do not. Our principal results, which are for models with Teff between 7200 K and 8500 K, are the following: First, th

Sergio Molinari, Alberto Noriega-Crespo

The HH 1/2 system has been observed with the two spectrometers on board the Infrared Space Observatory. Diffuse [CII] 158um emission indicate the presence of a Photo-Dissociation Region (PDR) which is only in part due to the external Far-UV irradiation from the nearby Orion Nebula. Additional irradiation must be originated locally and we show that the FUV fi

C. R. Benn

Earth is unusual in bearing life, and in having a large moon. A number of authors have suggested a possible connection between the two, e.g. through lunar stabilisation of the earth's obliquity, or through the effects of the oceanic tides. The various suggestions are reviewed.

Thomas Beckert, Heino Falcke

In inhomogeneous optically thick synchrotron sources a substantial part of the electron population at low energies can be hidden by self-absorption and overpowered by high energy electrons in optically thin emission. These invisible electrons produce Faraday rotation and conversion, leaving their footprints in the linear and circular polarized radiation of t

H. S. Park, G. G. Williams, D. H. Hartmann, D. Q. Lamb

We present multi-instrument optical observations of the High Energy Transient Explorer (HETE-2)/Interplanetary Network (IPN) error box of GRB 010921. This event was the first gamma ray burst (GRB) localized by HETE-2 which has resulted in the detection of an optical afterglow. In this paper we report the earliest known observations of the GRB010921 field, ta

G. L. Granato, G. DeZotti, L. Silva, L. Danese

In view of the extensive evidence of tight inter-relationships between spheroidal galaxies (and galactic bulges) with massive black holes hosted at their centers, a consistent model must deal jointly with the evolution of the two components. We describe one such model, which successfully accounts for the local luminosity function of spheroidal galaxies, for

Amedeo Balbi

I review the current status of cosmology as emerging from recent observations of cosmic microwave background anisotropies as well as from other sources of cosmological information.

Richard Massey, David Bacon, Alexandre Refregier, Richard Ellis

Cosmic shear probes the distribution of dark matter via gravitational lensing of distant, background galaxies. We describe our cosmic shear survey consisting of deep blank fields observed with the Keck II telescope. We have found biases in the standard weak lensing analysis, which are enhanced by the elongated geometry of the Keck fields. We show how these b

Alice K. Harding, Alexander Muslimov

We investigate the production of electron-positron pairs by inverse Compton scattered (ICS) photons above a pulsar polar cap (PC) and surface heating by returning positrons. This paper is a continuation of our self-consistent treatment of acceleration, pair dynamics and electric field screening above pulsar PCs. We calculate the altitude of the inverse Compt

A. Balbi, P. Cabella, G. de Gasperis, P. Natoli

We review the science case for studying CMB polarization. We then discuss the main issues related to the analysis of forth-coming polarized CMB data, such as those expected from balloon-borne (e.g. BOOMERanG) and satellite (e.g. Planck) experiments.

Ilidio Lopes, Joseph Silk

SNO measurements strongly constrain the central temperature of the Sun within a precision of much less than 1%. This result can be used to constrain the parameter space of SUSY dark matter particle candidates. In this first analysis we find a lower limit for the WIMP mass of 60 GeV, well above the WIMP evaporation limit of 10 GeV. Furthermore, in the event t

G. Dubus, R. E. Taam, H. C. Spruit

We investigate the structure and evolution of a geometrically thin viscous Keplerian circumbinary (CB) disk, using detailed models of their radiative/convective vertical structure. We use a simplified description for the evolution of the cataclysmic binary and focus on cases where the circumbinary disk causes accelerated mass transfer (> 1e-8 Msun/yr). The i

Agnieszka Janiuk, Joanna Kuraszkiewicz, Bozena Czerny

The central engine of the the Narrow Line Seyfert 1 galaxies is being probed. We use the ASCA and RXTE data to model the X-ray primary continuum as well as the reflected component and iron $Kα$ line. Since these are strongly coupled, we obtain independent measurements of the disc ionization level and the orientation dependent reflection amplitude. Using the

Agnieszka Janiuk, Bozena Czerny, Grzegorz M. Madejski

We propose a theoretical model to explain the spectrum of the quasar PG1211+143 emitted in the Optical/X-ray bands. In particular, we suggest that the inner accretion disk may develop a warm, optically thick skin, which produces a profound emission feature observed in the soft X-ray band. This is well modelled with the Comptonized black body emission. The sa

Torsten A. Ensslin, Rashid A. Sunyaev, Markus Brueggen

Powerful quasars and radio galaxies are injecting large amounts of energy in the form of radio plasma into the inter-galactic medium (IGM). Once this nonthermal component of the IGM has radiatively cooled the remaining radio emission is difficult to detect. Two scenarios in which the fossil radio plasma can be detected and thus be used to probe the IGM are d

Elmar Koerding, Heino Falcke, Sera Markoff

Recent X-ray observations reveal an increasing number of X-ray sources in nearby galaxies exceeding luminosities of L_x > 2 10^39 erg/s. Assuming isotropic emission, the Eddington limit suggests a population of intermediate-mass black holes of M_bh >> 10 M_sun. However, Markoff, Falcke, & Fender (2001) proposed that jets may be contributing to the X-ray emis

Eric van der Swaluw, Abraham Achterberg, Yves A. Gallant

We reconsider the rejuvenation mechanism as proposed by Shull, Fesen, & Saken (1989). These authors suggest that an active pulsar can catch up with, and rejuvenate the shell of the associated supernova remnant. The morphology of the SNRs G5.4-1.2 and CTB80 seem to confirm this rejuvenation mechanism. The spindown energy is deposited by the pulsar as a relati

S. Sazonov, E. Churazov, R. Sunyaev

As is known, resonant scattering can distort the surface-brightness profiles of clusters of galaxies in X-ray lines. We demonstrate that the scattered line emission should be polarized and possibly detectable with near-future X-ray polarimeters. Spectrally-resolved mapping of a galaxy cluster in polarized X-rays could provide valuable independent information

Charles H. Lineweaver

This article briefly summarizes the increasingly precise observational estimates of the cosmological parameters. After three years on the stump, the Lambda-CDM model is still the leading candidate. Although the Universe is expanding, our picture of it is coming together.

Russell B. Dahlburg, Giorgio Einaudi, T. N. LaRosa, Steven N. Shore

We simulate the Galactic Center nonthermal filaments as magnetized wakes formed dynamically from amplification of a weak (tens of $μ$G) global magnetic field through the interaction of molecular clouds with a Galactic Center wind. One of the key issues in this cometary model is the stability of the filament against dynamical disruption. Here we show 2-dimens

PACS Collaboration, M. Okamoto, S. Aoki, R. Burkhalter

We present a detailed study of the charmonium spectrum using anisotropic lattice QCD. We first derive a tree-level improved clover quark action on the anisotropic lattice for arbitrary quark mass. The heavy quark mass dependences of the improvement coefficients, i.e. the ratio of the hopping parameters $ζ=K_t/K_s$ and the clover coefficients $c_{s,t}$, are e

David Atwood, Amarjit Soni

We consider the possibility of studying the CP properties of various B(s) decays at an electro-positron machine tuned to the Upsilon(5s). Since decay modes of the B(s) with definite CP are relatively rare, we suggest that the use of more common modes which are not pure CP eigenstates may allow the determination of the CKM phase gamma. By studying the degree

Elliott H. Lieb, Robert Seiringer

The ground state of bosonic atoms in a trap has been shown experimentally to display Bose-Einstein condensation (BEC). We prove this fact theoretically for bosons with two-body repulsive interaction potentials in the dilute limit, starting from the basic Schroedinger equation; the condensation is 100% into the state that minimizes the Gross-Pitaevskii energy

N. B. Ivanov, J. Richter, D. J. J. Farnell

We study the zero-temperature phase diagram and the low-energy excitations of a mixed-spin ($S_1>S_2$) $J_1-J_2$ Heisenberg model defined on a square lattice by using a spin-wave analysis, the coupled cluster method, and the Lanczos exact-diagonalization technique. As a function of the frustration parameter $J_2/J_1$ ($ >0$), the phase diagram exhibits a qua

Irene D'Amico, Giovanni Vignale

We calculate the spin-drag transresistivity $ρ_{\uparrow \downarrow}(T)$ in a two-dimensional electron gas at temperature $T$ in the random phase approximation. In the low-temperature regime we show that, at variance with the three-dimensional low-temperature result [$ρ_{\uparrow\downarrow}(T) \sim T^2$], the spin transresistivity of a two-dimensional {\it s

Luis Álvarez-Cónsul, Oscar García-Prada

A twisted quiver bundle is a set of holomorphic vector bundles over a complex manifold, labelled by the vertices of a quiver, linked by a set of morphisms twisted by a fixed collection of holomorphic vector bundles, labelled by the arrows. When the manifold is Kaelher, quiver bundles admit natural gauge-theoretic equations, which unify many known equations f

Luis Álvarez-Cónsul, Oscar García-Prada

The so-called Hitchin-Kobayashi correspondence, proved by Donaldson, Uhlenbeck and Yau, establishes that an indecomposable holomorphic vector bundle over a compact Kahler manifold admits a Hermitian-Einstein metric if and only if the bundle satisfies the Mumford-Takemoto stability condition. In this paper we consider a variant of this correspondence for G-eq

Luigi Foschini

The logic--linguistic structure of quantum physics is analysed. The role of formal systems and interpretations in the representation of nature is investigated. The problems of decidability, completeness, and consistency can affect quantum physics in different ways. Bohr's complementarity is of great interest,because it is a contradictory proposition. We

Walter E. R. Cassani

As a substitute for the current hypothesis of space-time continuity, we show the nature and the characteristics of a Schild's discrete space-time. With the wave perturbations of its metrical structure we formulate the working hypothesis that all subatomic particles are elementary sources of spherical waves constituting on the whole the mass fields, the e

T. C. Ralph, N. K. Langford, T. B. Bell, A. G. White

We describe the operation and tolerances of a non-deterministic, coincidence basis, quantum CNOT gate for photonic qubits. It is constructed solely from linear optical elements and requires only a two-photon source for its demonstration.

M. R. Brown

The Floydian trajectory method of quantum mechanics and the appearance of microstates of the Schrödinger equation are reviewed and contrasted with the Bohm interpretation of quantum mechanics. The kinematic equation of Floydian trajectories is analysed in detail and a new definition of the variational derivative of kinetic energy with respect to total energy

M. I. Krivoruchenko

Dynamics of the major USA market indices DJIA, S&P, Nasdaq, and NYSE is analyzed from the point of view of the random walking problem with two-step correlations of the market moves. The parameters characterizing the stochastic dynamics are determined empirically from the historical quotes for the daily, weekly, and monthly series. The results show existence

M. F. M. Lutz, E. E. Kolomeitsev, C. L. Korpa

In this talk we review recent progress on the systematic evaluation of the kaon and antikaon spectral functions in dense nuclear matter based on a chiral SU(3) description of the low-energy pion-, kaon- and antikaon-nucleon scattering data.