November 2001 arXiv papers — page 5

F. Gieres, J. M. Grimstrup, H. Nieder, T. Pisar

Topological field theories of Schwarz-type generally admit symmetries whose algebra does not close off-shell, e.g. the basic symmetries of BF models or vector supersymmetry of the gauge-fixed action for Chern-Simons theory (this symmetry being at the origin of the perturbative finiteness of the theory). We present a detailed discussion of all these symmetrie

N. S. Mankoc Borstnik, H. B. Nielsen

We present a method to find solutions of the Weyl or the Dirac equation without specifying a representation choice for $γ^a$'s. By taking $γ^a$'s formally as independent variables, we construct solutions out of $2^d$ orthonormal polynomials of $γ^a$'s (in $d$-dimensional space) operating on a ``vacuum state''. Polynomials reduce into $2^{

L. C. Garcia de Andrade

Cosmological limits on Lorentz invariance breaking in Chern-Simons $(3+1)-dimensional$ electrodynamics are used to place limits on torsion. Birefrigence phenomena is discussed by using extending the propagation equation to Riemann-Cartan spacetimes instead of treating it in purely Riemannian spaces. The parameter of Lorentz violation is shown to be proportio

D. Kharzeev

I present recent results on the theory of QCD matter production in high energy heavy ion collisions and on the interactions of heavy quarks in such environment. The centrality and rapidity dependence of hadron production is evaluated in semi--classical approach. The energy loss of heavy quarks in matter is computed. The heavy--to--light meson ratio (e.g., D/

Jian-Jun Yang

We examine the SU(3) symmetry breaking in hyperon semileptonic decays (HSD) by considering two typical sets of quark contributions to the spin content of the octet baryons: Set-1 with SU(3) flavor symmetry and Set-2 with SU(3) flavor symmetry breaking in HSD. The quark distributions of the octet baryons are calculated with a successful statistical model. Usi

K. Redlich

We discuss experimental data on particle yields and particle spectra obtained in heavy ion collisions in a very broad energy range from SIS/GSI through AGS/BNL up to SPS/CERN and RHIC/BNL. We argue that in this broad energy range hadronic yields and their ratios resemble a thermal equilibrium population along a unified freeze--out curve determined by the con

Jian-Jun Yang

Based on a simple quark-diquark model, we propose a set of unpolarized, longitudinally polarized and transversely polarized fragmentation functions for the $Λ$ by fitting the unpolarized $Λ$ production data in $e^+ e ^- $ annihilation. It is found that the helicity structure of the obtained $Λ$ fragmentation functions is supported by the all available experi

C. Brenner Mariotto, M. B. Gay Ducati, G. Ingelman

Both hard and soft QCD dynamics are important in charmonium production, as presented here through a next-to-leading order QCD matrix element calculation combined with the colour evaporation model. Observed $x_F$ and $p_\perp$ distributions of $J/ψ$ in hadroproduction at fixed target and $p\bar{p}$ collider energies are reproduced. Quite similar results can a

M. A. Braun, E. G. Ferreiro, F. del Moral, C. Pajares

Calculations of the production rate of particles with $x>1$ in nuclear collisions due to the interaction of colour strings are presented. Momentum and colour sum rules are used to determine the fragmentation functions of fused strings. Mechanisms of the string interaction are considered with total and partial overlapping in the transverse plane. The results

S. D. Bass, A. De Roeck

We summarise the present status of the proton spin problem and the physics possibilities for future polarized ep and pp colliders. This summary is based on the presentations and discussion sessions at the workshop ``The Spin Structure of the Proton and Polarized Collider Physics'' (Trento, July 23-28, 2001).

Andreas S. Kronfeld

Theoretical and computational advances in lattice calculations are reviewed, with focus on examples relevant to the unitarity triangle of the CKM matrix. Recent progress in semi-leptonic form factors for B -> pi l nu and B -> D* l nu, as well as the parameter ξin B-Bbar mixing, are highlighted.

P. Bucci, M. Pietroni

Matsumoto and Yoshimura have recently argued that the number density of heavy particles in a thermal bath is not necessarily Boltzmann-suppressed for T<<M, as power law corrections may emerge at higher orders in perturbation theory. This fact might have important implications on the determination of WIMP relic densities. On the other hand, the definition of

Gong-Bo Zhao, Yi-Bing Ding, Xue-Qian Li, Guo-Li Wang

Friedberg, Lee and Zhao proposed a method for effectively evaluating the eigenenergies and eigen wavefunctions of quantum systems. In this work, we study several special cases to investigate applicability of the method. Concretely, we calculate the ground-state eigenenergy of the Hellmann potential as well as the Cornell potential, and also evaluate the ener

Francesco Vissani

Based on existing data, we argue for a peculiar structure of the neutrino mass matrix, that has a block of relatively large elements--a dominant block. We analyze this ansatz and extract its predictions, assuming that the O(1) coefficients (that are needed to define the model fully) are random variables. Further insights are obtained by postulating that this

E. S. Kokoulina

The Multiplicity distributions in high energy $e^+e^-$-annihilation are described within the Two Stage Model. It is shown that oscillations in sign of the ratio of factorial cumulant momentum to the factorial momentum of increasing order are confirmed. Parameters of parton stage and hadronization of this model are analysed.

B. J. W. van Tent, S. Groot Nibbelink

The calculation of scalar gravitational and matter perturbations during multiple-field inflation valid to first order in slow roll is discussed. These fields may be the coordinates of a non-trivial field manifold and hence have non-minimal kinetic terms. A basis for these perturbations determined by the background dynamics is introduced, and the slow-roll fu

J. Bordes, H. M. Chan, S. T. Tsou

The successful explanation of fermion mixing and of the fermion mass hierarchy by the Dualized Standard Model (DSM) scheme is based on the premises of a fermion mass matrix rotating in generation space with changing scales at a certain speed, which could in principle lead to sizeable flavour-violation observable in high sensitivity experiments such as BaBar.

S. Frixione

I discuss the current status of the comparison between theoretical predictions and experimental data, relevant to the production of open charm and bottom quarks in photon-hadron and photon-photon collisions. I advocate the use of a formalism that matches fixed-order computations to resummed computations in order to make firm statements on heavy flavour produ

E. Predazzi, O. V. Selyugin

The impact of the form of the hadron potential at large distances on the behaviour of the hadron spin-flip amplitude at small angles is examined. The $t$-dependence of the spin-flip amplitude of high energy hadron elastic scattering is analyzed under different assumptions on the hadron interaction. It is shown that the long tail of the non-Gaussian form of t

Rouzbeh Allahverdi, Mar Bastero-Gil, Anupam Mazumdar

We discuss the production of inflatino the superpartner of the inflaton due to vacuum fluctuations during preheating and argue that they do decay alongwith the inflaton to produce a thermal bath. Therefore they do not survive until nucleosynthsis to pose a threat to it.

Laura Covi

We review the prediction of inflation and the constraints on inflationary models coming from recent observations.

Elena G. Ferreiro

The strong suppression of the $J/ψ$ is studied in the framework of hadronic and quark gluon plasma models. Predictions for RHIC energies are presented.

Yuri V. Kovchegov, Kirill Tuchin

We calculate the cross section of a single inclusive gluon production in deep inelastic scattering at very high energies in the saturation regime, where the parton densities inside hadrons and nuclei are large and the evolution of structure functions with energy is nonlinear. The expression we obtain for the inclusive gluon production cross section is genera

K. Kang, J. R. Cudell, V. V. Ezhela, P. Gauron

We report on fits of a large class of analytic amplitude models for forward scattering against the comprehensive data for all available reactions. To differentiate the goodness of the fits of many possible parametrizations to a large sample of data, we developed and used a set of quantitative indicators measuring statistical quality of the fits over and beyo

Stefan Kurth

We compute the current quark mass in the Schrodinger functional with a non-vanishing background field at one loop order of perturbation theory. The results are used to obtain the critical mass at which the renormalized quark mass vanishes, and some lattice artefacts at one loop order.

C. Michael

Lattice QCD allows a first-principles study of QCD with the freedom to vary the number and masses of the quarks. I present results on the flavour singlet correlations (this illuminates OZI violating effects) for mesons. Concentrating on the pseudoscalar mesons, the flavour singlet mass splitting ($η$, $η&#39;$ mass splitting) appears naturally. I also presen

Robert G. Edwards, Urs M. Heller

We use low lying eigenvectors of the overlap-Dirac operator as a probe of the QCD vacuum. If instantons play a significant role one would expect the low lying eigenmodes of the overlap-Dirac operator to consist mainly of the mixed ``would be zero modes&#39;&#39;. Then, the eigenmodes should exhibit local chirality. Studying a recently introduced local chiral

A. Morales

An overview of the main strategies followed in the search for non-baryonic particle dark matter in the form of WIMPs is given. To illustrate these searches the case for Germanium ionization detectors is selected.

Marcelo S. Berman, Luis A. Trevisan

We find a static solution for the scale-factor in a Brans-Dicke generalized theory where the scalar field and the coupling constant vary with time. We find also that in the early Universe there may be amplification of gravitational waves.

G. S. Khadekar, Avinash R. Nagpure

A static conformally flat spherically symmetric perfect fluid cosmological model in Lyra geometry is investigatd.

Bernard F. Schutz

Gravitational wave detectors capable of making astronomical observations could begin to operate within the next year, and over the next 10 years they will extend their reach out to cosmological distances, culminating in the space mission LISA. A prime target of these observatories will be binary systems, especially those whose orbits shrink measurably during

Ivo Kwee, Marcus Hutter, Juergen Schmidhuber

We introduce a learning method called ``gradient-based reinforcement planning&#39;&#39; (GREP). Unlike traditional DP methods that improve their policy backwards in time, GREP is a gradient-based method that plans ahead and improves its policy before it actually acts in the environment. We derive formulas for the exact policy gradient that maximizes the expe

M. Guenza

We investigate the anomalous dynamics of unentangled polymer melts. The proposed equation of motion formally relates the anomalous center-of-mass diffusion, as observed in computer simulations and experiments, to the nature of the effective intermolecular mean-force potential. An analytical Gaussian-core form of the potential between the centers of mass of t

Amlan Biswas, P. Fournier, M. M. Qazilbash, V. N. Smolyaninova

We present point contact spectroscopy (PCS) data for junctions between a normal metal and the electron doped cuprate superconductor Pr$_{2-x}$Ce$_x$CuO$_4$ (PCCO). For the underdoped compositions of this cuprate ($x \sim 0.13$) we observe a peak in the conductance-voltage characteristics of the point contact junctions. The shape and magnitude of this peak su

A. F. Santander-Syro, R. P. S. M. Lobo, N. Bontemps, Z. Konstantinovic

The in-plane optical conductivity of Bi2Sr2CaCu2O8+d thin films with small carrier density (underdoped) up to large carrier density (overdoped) is analyzed with unprecedented accuracy. Integrating the conductivity up to increasingly higher energies points to the energy scale involved when the superfluid condensate builds up. In the underdoped sample, states

B. Rosenow, V. Plerou, P. Gopikrishnan, H. E. Stanley

Diversification of an investment into independently fluctuating assets reduces its risk. In reality, movement of assets are are mutually correlated and therefore knowledge of cross--correlations among asset price movements are of great importance. Our results support the possibility that the problem of finding an investment in stocks which exposes invested f

M. Nicastro, C. H. Patterson

The equilibrium structure and exchange constants of CaMnO$_3$ and LaMnO$_3$ have been investigated using total energy unrestricted Hartree-Fock (UHF) and localised orbital configuration interaction (CI) calculations on the bulk compounds and Mn$_2$O$_{11}^{14-}$ and Mn$_2$O$_{11}^{16-}$ clusters. The predicted structure and exchange constants for CaMnO$_3$ a

A. Pottmeier, R. Barlovic, W. Knospe, A. Schadschneider

We study the impact of a localized defect in a cellular automaton model for traffic flow which exhibits metastable states and phase separation. The defect is implemented by locally limiting the maximal possible flow through an increase of the deceleration probability. Depending on the magnitude of the defect three phases can be identified in the system. One

P. Monthoux, D. J. Scalapino

Results of a phenomenological Monte carlo calculation for a 2D electron-phonon Holstein model near a Peierls-CDW transition are presented. Here the zero Matsubara frequency part of the phonon action is dominant and we approximated it by a phenomenological form that as an Ising-like Peierls-CDW transition. The resulting model is studied on a 32 by 32 lattice.

A. A. Katanin, A. P. Kampf

We consider the square lattice Heisenberg antiferromagnet with plaquette ring exchange and a finite interlayer coupling leading to a consistent description of the spin-wave excitation spectrum in La2CuO4. The values of the in-plane exchange parameters, including ring-exchange J_{\Box}, are obtained consistently by an accurate fit to the experimentally observ

Arkadiusz Wojs, John J. Quinn

The inter-Landau-level spin excitations of quantum Hall states at filling factors nu=2 and 4/3 are investigated by exact numerical diagonalization for the situation in which the cyclotron (hbar*omega_c) and Zeeman (E_Z) splittings are comparable. The relevant quasiparticles and their interactions are studied, including stable spin wave and skyrmion bound sta

Alexander K. Hartmann, Heiko Rieger

Here practical aspects of conducting research via computer simulations are discussed. The following issues are addressed: software engineering, object-oriented software development, programming style, macros, make files, scripts, libraries, random numbers, testing, debugging, data plotting, curve fitting, finite-size scaling, information retrieval, and prepa

Jaume Masoliver, Miquel Montero, Josep Perello

The analysis which assumes that tick by tick data is linear may lead to wrong conclusions if the underlying process is multiplicative. We compare data analysis done with the return and stock differences and we study the limits within the two approaches are equivalent. Some illustrative examples concerning these two approaches are given. Actual data is taken

M. Eremin, I. Eremin

In a frame of the $t-J-G$ model we derive the microscopical expression for the circulating orbital currents in layered cuprates using the anomalous correlation functions. In agreement with $μ$-on spin relaxation ($μ$SR), nuclear quadrupolar resonance (NQR) and inelastic neutron scattering(INS) experiments in YBa$_2$Cu$_3$O$_{6+x}$ we successfully explain the

D. Sanchez, J. A. Alonso, M. Garcia-Hernandez, M. J. Martinez-Lope

Anti-site disordering in Sr2FeMoO6 double perovskites (containing Mo atoms at Fe positions, and viceversa) has recently been shown to have a dramatic influence in their magnetic and magnetotransport properties. In the present study, two polycrystalline Sr2FeMoO6 samples showing different degrees of anti-site disorder (a nominally &#39;ordered&#39; sample wit

E. K. O. Hellen, P. E. Salmi, M. J. Alava

We study the probability, $P_S(t)$, of a cluster to remain intact in one-dimensional cluster-cluster aggregation when the cluster diffusion coefficient scales with size as $D(s) \sim s^γ$. $P_S(t)$ exhibits a stretched exponential decay for $γ< 0$ and the power-laws $t^{-3/2}$ for $γ=0$, and $t^{-2/(2-γ)}$ for $0<γ<2$. A random walk picture explains the disc

Yoshihiro Suwa, Kanako Goto, Kazumi Ochi, Yoshuyuki Saito

Mechanism for acceleration of phase separation in Fe-base ternary alloys was investigated with use of a model based on the Cahn-Hilliard equation. Behavior of the minor element in an Fe-base ternary alloy along the trajectory of the peak of the major element is dependent on the sign of the second derivative of the chemical free energy with respect to the con

S. Mossa, E. La Nave, H. E. Stanley, C. Donati

We study thermodynamic and dynamic properties of a rigid model of the fragile glass forming liquid orthoterphenyl. A system of N=343 molecules is considered in a wide range of densities and temperatures, reaching simulation times up to 1 microsecond. Working within the inherent structures thermodynamic formalism, we present results for the temperature and de

Sang-Hoon Kim, Peter Pfeifer

The Bose condensation of a stack of low dimensional disks which is composed of a noninteracting charged Bose gas in a uniform magnetic field is studied. A statistical approach with density of states at noninteger dimensions are applied for the system. The condensate fraction of the disk system in a uniform magnetic field is calculated. The stack of low dimen

Fiona Hoyle, Michael S. Vogeley, J. Richard Gott

We study the topology of the publicly available data released by the 2dFGRS. The 2dFGRS data contains over 100,000 galaxy redshifts with a magnitude limit of b_J=19.45 and is the largest such survey to date. The data lie over a wide range of right ascension (75 degree strips) but only within a narrow range of declination (10 degree and 15 degree strips). Thi

C. Schuster, M. Pohl, R. Schlickeiser

Active galactic nuclei (AGN) are known as sources of high energy gamma-rays. The emission probably results from non-thermal radiation of relativistic jets belonging to the AGN. Earlier investigations of these processes have suggested that neutrinos are among the radiation products of the jets and may be used to discriminate between hadrons and leptons as pri

David Charbonneau, Timothy M. Brown, Robert W. Noyes, Ronald L. Gilliland

We report high precision spectrophotometric observations of four planetary transits of HD 209458, in the region of the sodium resonance doublet at 589.3 nm. We find that the photometric dimming during transit in a bandpass centered on the sodium feature is deeper by (2.32 +/- 0.57) x 10^{-4} relative to simultaneous observations of the transit in adjacent ba

W. H. de Vries, R. Morganti, H. J. A. Rottgering, R. Vermeulen

We present the results from our deep (16x12 hour) Westerbork Synthesis Radio Telescope (WSRT) observations of the approximately 7 square degree Bootes Deep Field, centered at 14h32m05.75s, 34d16&#39;47.5&#34; (J2000). Our survey consists of 42 discrete pointings, with enough overlap to ensure a uniform sensitivity across the entire field, with a limiting sen

Soeren S. Larsen, Jean P. Brodie

We present Keck/LRIS spectra for 11 old globular clusters in the S0-type galaxy NGC 1023 and 2 young blue clusters in the nearby companion NGC 1023A. Analysis of the spectra of 7 old clusters with sufficient S/N shows generally good agreement between spectroscopic and previous photometric metallicity estimates, but the integrated colors of two clusters are t

Cesar A. Caretta, Marcio A. G. Maia, Wataru Kawasaki, Christopher N. A. Willmer

We study the distribution of galaxies and galaxy clusters in a 10^deg x 6^deg field in the Aquarius region. In addition to 63 clusters in the literature, we have found 39 new candidate clusters using a matched-filter technique and a counts-in-cells analysis. From redshift measurements of galaxies in the direction of these cluster candidates, we present new m

J. Greiner

I summarize recent near-infrared spectroscopy of the microquasar GRS 1915+105 with the ESO/VLT which allowed to (i) identify the donor and (ii) measure the orbital period and radial velocity amplitude. Assuming that the jet ejections occur perpendicular to the accretion disk and orbital plane, the mass of the black hole is determined to M = 14 +- 4 solar mas

J. M. Costa, L. da Silva, J. D. do Nascimento, J. R. De Medeiros

We analise the behavior of lithium abundance as a function of effective temperature, projected rotational velocity, orbital period and eccentricity for a sample of 68 binary systems with giant component and orbital period ranging from about 10 to 6400 days. For these binary systems the Li abundances show a gradual decrease with temperature, paralleling the w

J. Greiner, J. G. Cuby, M. J. McCaughrean

Here we report a measurement of the orbital period and mass function of GRS 1915+105 which allow us to deduce a mass of 14 +- 4 solar masses for its black hole. This large mass provides a challenge for black hole formation scenarios in binaries, since black holes with masses above 5-7 solar masses are hard to explain. Also, the mass estimate allows us to und

Gordon Petrie, Nektarios Vlahakis, Kanaris Tsinganos

We present a systematic method for constructing two-dimensional magnetohydrodynamic equilibria with compressible flow in Cartesian geometry. This systematic method has already been developed in spherical geometry and applied in modelling solar and stellar winds and outflows (Vlahakis & Tsinganos,1998) but is derived here in Cartesian geometry in the context

Neven Bilic, Faustin Munyaneza, Gary B. Tupper, Raoul D. Viollier

After a discussion of the properties od degenerate fermion balls, we analize the orbits of the star S0-1, which has the smallest projected distance to Sgr A*, in the supermassive black hole as well as in the fermion ball scenarios of the Galactic center. It is shown that both scenarios are consistent with the data,as measured during the last six yiers by Gen

Fulvio Pompilio, Marco Montuori

We present a cosmological model in which the metric allows for an inhomogeneous Universe with no intrinsic symmetries (Stephani models), providing the ideal features to describe a fractal distribution of matter. Constraints on the metric functions are derived using the expansion and redshift relations and allowing for scaling number counts, as expected in a

R. Ignace, K. G. Gayley

We consider the consequences of appreciable line optical depth for the profile shape of X-ray emission lines formed in stellar winds. The hot gas is thought to arise in distributed wind shocks, and the line formation is predominantly via collisional excitation followed by radiative decay. Such lines are often modelled as optically thin, but the theory has di

B. Ciardi, S. Bianchi, A. Ferrara

We have studied the effects of gas density inhomogeneities on the escape of ionising Lyman continuum (Lyc) photons from Milky Way-type galaxies via 3D numerical simulations using the Monte Carlo radiative transfer code CRASH (Ciardi et al. 2001). To this aim a comparison between a smooth Gaussian distribution (GDD) and an inhomogeneous, fractal one (FDD) has

Pasquale Blasi, Rainer Dick, Edward W. Kolb

We investigate the possibility that ultra-high energy cosmic rays (UHECRs) originate from the annihilation of relic superheavy (SH) dark matter in the Galactic halo. In order to fit the data on UHECRs, a cross section of $<σ_Av>\sim 10^{-26}\textrm{cm}^2 (M_X/10^{12} \textrm{GeV})^{3/2}$ is required if the SH dark matter follows a Navarro--Frenk--White (NFW)

Ilidio P. Lopes, Joseph Silk, Steen H. Hansen

The presence of dark matter in the solar neighbourhood can be tested in the framework of stellar evolution theory by using the new results of helioseismology. If weakly interacting massive particles accumulate in the center of the Sun, they can provide an additional mechanism for transferring energy from the solar core. The presence of these particles produc

Pasquale Blasi

First order Fermi acceleration at astrophysical shocks is often invoked as a mechanism for the generation of non-thermal particles. This mechanism is especially simple in the approximation that the accelerated particles behave like test particles, not affecting the shocked fluid. Many complications enter the calculations when the accelerated particles have a

S. Andreon, J. -C. Cuillandre

[Abridged] We determined the luminosity function (LF) of the Coma cluster galaxies selected by luminosity, and the LF bi-variate in central brightness. The Coma cluster and control fields were imaged using the CFH12K (42x28 arcmin) and UH8K (28x28 arcmin) wide-field cameras at the CFHT. Selected HST images were used for testing. Quantities were derived from

A. Cimatti, E. Daddi, M. Mignoli, L. Pozzetti

We present the results of VLT optical spectroscopy of a complete sample of 78 EROs with R-Ks\geq5 over a field of 52 arcmin^2. About 70% of the 45 EROs with Ks\leq19.2 have been spectroscopically identified with old passively evolving and dusty star-forming galaxies at 0.7<z<1.5. The two classes are about equally populated and for each of them we present and

Daniela Calzetti, Jason Harris

We present preliminary results of a long-term study aimed at answering a number of open questions on the evolution of starbursts in local galaxies. The project employes mainly HST data from the ultraviolet to the red of the stellar continuum and of the nebular emission from the galaxies. Here we concentrate on NGC5253 and NGC5236 (M83), that form a dwarf--ma

Alexander Sakharov, Maxim Khlopov, Sergei Rubin

The whole set of astrophysical data indicates that our Universe is globally baryon asymmetrical. Nevertheless a possibility of existence of relatively small amount of sufficiently large antimatter regions is not excluded. Such regions can survive the annihilation with surrounding matter only in the case if their sizes exceed a certain scale. It is shown that

I. M. George, T. J. Turner, H. Netzer, S. B. Kraemer

We present the first high-resolution, X-ray image of the circumnuclear regions of the Seyfert 1 galaxy NGC 3516, using the Chandra X-ray Observatory (CXO). All three of the CXO observations reported were performed with one of the two grating assemblies in place, and here we restrict our analysis to undispersed photons (i.e. those detected in the zeroth-order

M. Pohl, I. Lerche, R. Schlickeiser

To address the important issue of how kinetic energy of collimated blast waves is converted into radiation, Pohl & Schlickeiser (2000) have recently investigated the relativistic two-stream instability of electromagnetic turbulence. They have shown that swept-up matter is quickly isotropized in the blast wave, which provides relativistic particles and, as a

H. Meusinger, B. Stecklum, Ch. Theis, J. Brunzendorf

We examine the merger stage of IRAS 03158+4227, one of the most luminous ULIRGs from the IRAS 2 Jy sample. Deep optical images are presented along with high-resolution NIR images and optical low-resolution spectra. IRAS 03158+4227 is confirmed as a component of an equal-luminosity binary galaxy with a nuclei separation of 47 / (h/75) kpc. A long lopsided tai

Frank J. Tipler

I show that the mutual consistency of the Bekenstein Bound, the Standard Model (SM) of particle physics, and general relativity implies that the universe began in a unique state. I solve the coupled EYM equations for this unique state, show how the horizon problem is solved, and how SM baryogenesis naturally results from the triangle anomoly. Since the SU(2)

A. A. Louis, P. G. Bolhuis, E. J. Meijer, J. P. Hansen

The surface tension of interacting polymers in a good solvent is calculated theoretically and by computer simulations for a planar wall geometry and for the insertion of a single colloidal hard-sphere. This is achieved for the planar wall and for the larger spheres by an adsorption method, and for smaller spheres by a direct insertion technique. Results for

A. J. M. Medved

We consider a brane universe in an asymptotically de Sitter background spacetime of arbitrary dimensionality. In particular, the bulk spacetime is described by a ``topological de Sitter&#39;&#39; solution, which has recently been investigated by Cai, Myung and Zhang. In the current study, we begin by showing that the brane evolution is described by Friedmann

J. Erlich, C. Grojean

It has very recently been demonstrated by Csaki, Kaloper and Terning (CKT) that the faintness of supernovae at high redshift can be accommodated by mixing of a light axion with the photon in the presence of an intergalactic magnetic field, as opposed to the usual explanation of an accelerating universe by a dark energy component. In this paper we analyze fur

Adrian Dumitru, Jamal Jalilian-Marian

We prove that the inclusive single-gluon production cross section for a hadron colliding with a high-density target factorizes into the gluon distribution function of the projectile, defined as usual within the DGLAP collinear approximation, times the cross section for scattering of a single gluon on the strong classical color field of the target. We then de

Antonio Padilla

We examine the cosmological evolution equations of de Sitter, flat and anti-de Sitter braneworlds sandwiched in between two n dimensional AdS-Schwarzschild spacetimes. We are careful to use the correct form for the induced Newton&#39;s constant on the brane, and show that it would be naive to assume the energy of the bulk spacetime is just given by the sum o

Glenn Barnich, Friedemann Brandt

Under suitable assumptions on the boundary conditions, it is shown that there is a bijective correspondence between equivalence classes of asymptotic reducibility parameters and asymptotically conserved n-2 forms in the context of Lagrangian gauge theories. The asymptotic reducibility parameters can be interpreted as asymptotic Killing vector fields of the b

Alejandro Cabo, Francisco Claro, Alejandro Perez

The CDW Hartree-Fock state at half filling and half electron per unit cell is examined. Firstly, an exact solution in terms of Bloch-like states is presented. Using this solution we discuss the dynamics near half filling and show the mass to diverge logarithmically as this filling is approached. We also show how a uniform density state may be constructed fro

E. Anderson, F. Dahia, James E. Lidsey, C. Romero

The extension of the Campbell-Magaard embedding theorem to general relativity with minimally-coupled scalar fields is formulated and proven. The result is applied to the case of a self-interacting scalar field for which new embeddings are found, and to Brans-Dicke theory. The relationship between Campbell-Magaard theorem and the general relativity, Cauchy an

A. M. Dikande

Lattice effects on the kink families of two models for one-dimensional nonlinear Klein-Gordon systems with double-well on-site potentials are considered. The analytical expression of the generalized Peierls-Nabarro pinning potential is obtained and confronted with numerical simulations.

Nazar Ikhsanov

The supersonic propeller spindown of a neutron star moving in a strong stellar wind of its massive companion is discussed. I show that the supersonic propeller model presented by Davies & Pringle (1981}) is self-consistent if the strength of the stellar wind of the normal companion is \dot{M}_{\rm c} \la 2.2 10^{18} (M_{\rm ns}/M_{\sun}) V_8 g/s. Under these

Stephen C. Davis

Brane cosmologies with static, five-dimensional and Z_2 symmetric bulks are analysed. A general solution generating mechanism is outlined. The qualatitive cosmological behaviour of all such solutions is determined. Conditions for avoiding naked bulk singularities are also discussed. The restrictions placed on the solutions by the assumption of such a static

H. Boukari, P. Kossacki, M. Bertolini, D. Ferrand

A strong influence of illumination and electric bias on the Curie temperature and saturation value of the magnetization is demonstrated for semiconductor structures containing a modulation-doped p-type Cd0.96Mn0.04Te quantum well placed in various built-in electric fields. It is shown that both light beam and bias voltage generate an isothermal and reversibl

Gautam Bhattacharyya, K. Sridhar

In a model of supersymmetric SU(5) Grand Unification with a spatial dimension described by the orbifold $S^1/(Z_2 \times Z_2&#39;)$, proton decay is naturally suppressed at all orders. This is achieved by a suitable implementation of the discrete symmetries on the brane. But baryon number violating interactions are present in this model. We propose a few pos

M. Burkardt, Y. Koike

Sum rules for twist-3 distributions are reexamined. Integral relations between twist-3 and twist-2 parton distributions suggest the possibility for a $δ$-function at $x=0$. We confirm and clarify this result by constructing $h_L$ and $h_L^3$ (quark-gluon interaction dependent part of $h_L$) explicitly from their moments for a one-loop dressed massive quark.

J. I. Latorre, M. A. Martin-Delgado

We apply majorization theory to study the quantum algorithms known so far and find that there is a majorization principle underlying the way they operate. Grover&#39;s algorithm is a neat instance of this principle where majorization works step by step until the optimal target state is found. Extensions of this situation are also found in algorithms based in

Matej Pavsic

The long standing problem of the ordering ambiguity in the definition of the Hamilton operator for a point particle in curved space is naturally resolved by using the powerful geometric calculus based on Clifford Algebra. The momentum operator is defined to be the vector derivative (the gradient) multiplied by $-i$; it can be expanded in terms of basis vecto

A. Cody, Dimitar D. Sasselov

The Sun-like star HD209458 harbors a close-in giant planet which transits across the star&#39;s disk, and thus allows an unprecedented access to the basic parameters of the planet, given a certain knowledge of the basic parameters of the star, namely its mass and radius. We present theoretical stellar evolution model calculations for HD 209458 and discuss th

C. I. Lazaroiu

I consider the semiclassical approximation of the graded Chern-Simons field theories describing certain systems of topological A type branes in the large radius limit of Calabi-Yau compactifications. I show that the semiclassical partition function can be expressed in terms of a certain (differential) numerical invariant which is a version of the analytic to

Martin White, Ludovic van Waerbeke, Jonathan Mackey

Using mock observations of numerical simulations, we investigate the completeness and efficiency of searches for galaxy clusters in weak lensing surveys. While it is possible to search for high mass objects directly as density enhancements using weak lensing, we find that line-of-sight projection effects can be quite serious. For the search methods that we c

C. McKenzie, J. Hecker Denschlag, H. Haeffner, A. Browaeys

We report on the formation of ultra-cold Na$_2$ molecules using single-photon photoassociation of a Bose-Einstein condensate. The photoassociation rate, linewidth and light shift of the J=1, $v=135$ vibrational level of the \mterm{A}{1}{+}{u} molecular bound state have been measured. We find that the photoassociation rate constant increases linearly with int

J. Clausen, L. Knoell, D. -G. Welsch

A generalized Mach-Zehnder-type interferometer equipped with cross-Kerr elements is proposed to convert N-photon truncated single-mode quantum states into (N+1)-mode single-photon states, which are suitable for further state manipulation by means of beam splitter arrays and ON/OFF-detections, and vice versa. Applications to the realization of unitary and non

Katarzyna Krajewska, Jerzy Z. Kaminski

It is shown that the renormalizability of the zero-range interaction in the two-dimensional space is always followed by the existence of a bound state, which is not true for odd-dimensional spaces. A renormalization procedure is defined and the exact retarded Green&#39;s function for electrons moving in two dimensions and interacting with both crossed magnet

E. Jane, M. B. Plenio, D. Jonathan

We demonstrate that quantum information processing can be implemented with ions trapped in a far detuned optical cavity. For sufficiently large detuning the system becomes insensitive to cavity decay. Following recent experimental progress, this scheme can be implemented with currently available technology.

N. B. Narozhny, M. S. Fofanov

We describe a realistic model for a focused high-intensity laser pulse in three dimensions. Relativistic dynamics of an electron submitted to such pulse is described by equations of motion with ponderomotive potential depending on a single free parameter in the problem, which we refer to as the &#34;asymmetry parameter&#34;. It is shown that the asymmetry pa

Daniel R. Terno

The representation of measurements by positive operator valued measures and the description of the most general state transformations by means of completely positive maps are two basic concepts of quantum information theory. These concepts can be trivially extended to field theories in curved spacetime if all the representations of canonical commutation or a

T. Djama

Using the relativistic quantum Hamilton-Jacobi equation within the framework of the equivalence postulate, and grounding one self on both relativistic and quantum Lagrangians, we construct a Lagrangian of relativistic quantum system in one dimension and derive a third order equation of motion representing a first integral of the relativistic quantum Newton&#