January 2001 arXiv papers — page 18

Gregory Soyez

Working in light-cone coordinates, we study the zero-modes and the vacuum in a 2+1 dimensional SU(3) gauge model. Considering the fields as independent of the tranverse variables, we dimensionally reduce this model to 1+1 dimensions. After introducing an appropriate su(3) basis and gauge conditions, we extract an adjoint field from the model. Quantization of

S. Ansoldi, C. Castro, E. Spallucci

We consider the reduced, quenched version of a generalized Yang-Mills action in 4k-dimensional spacetime. This is a new kind of matrix theory which is mapped through the Weyl-Wigner-Moyal correspondence into a field theory over a non-commutative phase space. We show that the ``classical'' limit of this field theory is encoded into the effective actio

I. V. Tyutin

We study the general form of the *-commutator treated as a deformation of the Poisson bracket on the Grassman algebra. We show that, up to a similarity transformation, there are other deformations of the Poisson bracket in addition to the Moyal commutator (one at even and one at odd n, n is the number of the generators of the Grassman algebra) which are not

Takao Koikawa

We investigate the equation where the commutation relation in 2-dimensional zero-curvature equation composed of the algebra-valued potentials is replaced by the Moyal bracket and the algebra-valued potentials are replaced by the non-algebra-valued ones with two more new variables. We call the 4-dimensional equation the noncommutative zero-curvature equation.

Riccardo D'Auria, Sergio Ferrara, Silvia Vaulà

F(4) supergravity, the gauge theory of the exceptional six-dimensional Anti-de Sitter superalgebra, is coupled to an arbitrary number of vector multiplets whose scalar components parametrize the quaternionic manifold SO(4,n)/SO(4)\times SO(n). By gauging the compact subgroup SU(2)_d \otimes G, where SU(2)_d is the diagonal subgroup of SO(4)= SU(2)_L\otimes S

Stefano Bellucci, Armen Nersessian

The geometric models of N=4 supersymmetric mechanics with $(2d.2d)_{\DC}$-dimensional phase space are proposed, which can be viewed as one-dimensional counterparts of two-dimensional N=2 supersymmetric sigma-models by Alvarez-Gaum\'e and Freedman. The related construction of supersymmetric mechanics whose phase space is a K\"ahler supermanifold is considered

Iosif Bena, Diana Vaman

We construct an M-theory dual of a 6 dimensional little string theory with reduced supersymmetry, along the lines of Polchinski and Strassler. We find that upon perturbing the (2,0) theory with an R-current, the M5 branes polarize into a wrapped Kaluza Klein monopole, whose isometry direction is along the R current. We investigate the properties of this theo

A. Bohm, H. Kaldass, S. Wickramasekara

A state vector description for relativistic resonances is derived from the first order pole of the $j$-th partial $S$-matrix at the invariant square mass value $\sm_R=(m-iΓ/2)^2$ in the second sheet of the Riemann energy surface. To associate a ket, called Gamow vector, to the pole, we use the generalized eigenvectors of the four-velocity operators in place

Gino Isidori

Rare flavour-changing neutral-current transitions of the type $s \to d \ell^+\ell^-(ν\barν)$ and $b \to s \ell^+\ell^-(ν\barν)$ are analysed in supersymmetric extensions of the Standard Model with generic flavour couplings. It is shown that these processes are particularly sensitive to the left--right mixing of the squarks and that, in the presence of non-un

Jackie Grant, Mark Hindmarsh

We undertake a comprehensive investigation of the properties of the sphaleron in electroweak theories with two Higgs doublets. We do this in as model-independent a way as possible: by exploring the physical parameter space described by the masses and mixing angles of the Higgs particles. If there is a large split in the masses of the neutral Higgs particles,

Robert H. Brandenberger

The first aim of this lecture is to highlight two areas of recent progress in inflationary cosmology, namely reheating and the quantum theory of cosmological perturbations. The second aim is to discuss important conceptual problems for the current realizations of inflation based on fundamental scalar matter fields, and to present some new approaches at solvi

Marco Battaglia, Stefania De Curtis, Daniele Dominici, Arnaud Ferrari

Several models predict the existence of new resonances in the multi-TeV region, which should be accessible in e+e- collisions by s-channel production. In this paper, we review the phenomenology of some specific models and we present a preliminary study of the potential of the future CLIC collider for the determination of their nature and properties.

R. Bonnaz, B. Silvestre-Brac, C. Gignoux

In the framework of the non relativistic quark model, an exhaustive study of radiative transitions in mesons is performed. The emphasis is put on several points. Some traditional approximations (long wave length limit, non relativistic phase space, dipole approximation for E1 transitions, gaussian wave functions) are analyzed in detail and their effects comm

J. Kalinowski

The chargino and neutralino pair production processes at $e^+e^-$ collisions are explored to determine the underlying SUSY parameters. The sum rules for the couplings are used to check the closure of two-chargino and four-neutralino systems in the minimal supersymmetric extension of the standard model.

Heui-Seol Roh

It is shown that quantum nucleardynamics (QND) as an SU(2)_N \times U(1)_Z gauge theory, which is generated from quantum chromodynamics (QCD) as an SU(3)_C gauge theory through dynamical spontaneous symmetry breaking, successfully describes nuclear phenomena at low energies. The proton and neutron assigned as a strong isospin doublet are identified as a colo

Heui-Seol Roh

This study proposes that the longstanding problems of quantum chromodynamics (QCD) as an SU(3)_C gauge theory, the confinement mechanism and Θvacuum, can be resolved by dynamical spontaneous symmetry breaking (DSSB) through the condensation of singlet gluons and quantum nucleardynamics (QND) as an SU(2)_N \times U(1)_Z gauge theory is produced. The confineme

N. Suzuki, M. Biyajima

Fractional derivative in time variable is introduced into the Fokker-Planck equation of a population growth model. It's solution, the KNO scaling function, is transformed into the generating function for the multiplicity distribution. Formulas of the factorial moment and the $H_j$ moment are derived from the generating function, which reduces to that of

Giovanni Punzi

A novel way of defining limits in classical statistics is proposed. This is a natural extension of the original Neyman's method, and has the desirable property that only information relevant to the problem is used in making statistical inferences. The result is a strong restriction on the allowed confidence bands, excluding in full generality pathologies

The OPAL collaboration, G. Abbiendi

A search for the Standard Model Higgs boson has been performed with the OPAL detector at LEP based on the full data sample collected at sqrt(s) = 192-209 GeV in 1999 and 2000, corresponding to an integrated luminosity of approximately 426 pb-1. The data are examined for their consistency with the background-only hypothesis and various Higgs boson mass hypoth

Thomas W. Baumgarte

Newtonian point mass binaries can be brought into arbitrarily close circular orbits. Neutron stars and black holes, however, are extended, relativistic objects. Both finite size and relativistic effects make very close orbits unstable, so that there exists an innermost stable circular orbit (ISCO). We illustrate the physics of the ISCO in a simple model prob

V. D. Ivashchuk, V. S. Manko, V. N. Melnikov

Black hole p-brane solutions for a wide class of intersection rules are considered. The solutions are defined on a manifold which contains a product of n-1 Ricci-flat "internal'' spaces. The post-Newtonian parameters "beta" and "gamma" corresponding to a 4-dimensional section of the metric for general intersection rules are studie

V. D. Ivashchuk, M. Kenmoku, V. N. Melnikov

In a multidimensional model with several scalar fields and an m-form we deal with classical spherically symmetric solutions with one (electric or magnetic) p-brane and Ricci-flat internal spaces and the corresponding solutions to the Wheeler--DeWitt (WDW) equation. Classical black holes are considered and their quantum analogues (e.g. for M2 and M5 extremal

H. F. Dowker, R. D. Sorkin

We present a review of the spin and statistics of topological geons, particles in 3+1 quantum gravity. They can have half-odd-integral spin and fermionic statistics and since the underlying gravitational field is tensorial and bosonic, this is an example of ``emergent'' non-trivial spin and statistics as displayed by familiar non-gravitating objects

Raymond Smith, Bogdan Korel

Debugging of large software systems consisting of many processes accessing shared resources is a very difficult task. Many commercial systems record essential events during system execution for post-mortem analysis. However, the event traces of large and long-running systems can be quite voluminous. Analysis of such event traces to identify sources of incorr

Roberto Capote, Alain Delgado, Augusto Gonzalez

The structure of E1 resonances is examined in a microscopic random phase approximation calculation for neutral, symmetric, closed shell, electron-hole systems in a quantum dot. The number of electron-hole pairs, N, is varied from 6 to 42. The ocurrence of small, but distinct, E1 peaks in the far infrared spectra located in the low energy tail of the giant di

Rafaella A. Nobrega, Cricia C. Rodegheri, Renato C. Povoas

Brazilian drivers caught in traffic violations accumulate points in their official personal files. Here, we analyse the distribution probability of these data, for the state of Rio de Janeiro, where 4199 drivers accumulated 20 or more penalty points during one year.

Paulo Murilo Castro de Oliveira

The Broad Histogram Method (BHM) allows one to determine the energy degeneracy g(E), i.e. the energy spectrum of a given system, from the knowledge of the microcanonical averages <Nup(E)> and <Ndn(E)> of two macroscopic quantities Nup and Ndn defined within the method. The fundamental BHM equation relating g(E) to the quoted averages is exact and completely

Paulo Murilo Castro de Oliveira

The long-term behaviour of dynamic systems can be classified in two different regimes, regular or chaotic, depending on the values of the control parameters, which are kept constant during the time evolution. Starting from slightly different initial conditions, a regular system converges to the same final trajectory, whereas a chaotic system follows two dist

N. Akino, F. Schmid, M. P. Allen

We present large-scale molecular dynamics simulations of a nematic-isotropic interface in a system of repulsive ellipsoidal molecules, focusing in particular on the capillary wave fluctuations of the interfacial position. The interface anchors the nematic phase in a planar way, i.e., the director aligns parallel to the interface. Capillary waves in the direc

F. Kirchhoff, M. J. Mehl, N. I. Papanicolaou, D. A. Papaconstantopoulos

We studied the dynamical properties of Au using our previously developed tight-binding method. Phonon-dispersion and density-of-states curves at T=0 K were determined by computing the dynamical-matrix using a supercell approach. In addition, we performed molecular-dynamics simulations at various temperatures to obtain the temperature dependence of the lattic

M. Tissier, B. Delamotte, D. Mouhanna

Frustrated magnets are a notorious example where usual perturbative methods fail. Having recourse to an exact renormalization group approach, one gets a coherent picture of the physics of Heisenberg frustrated magnets everywhere between d=2 and d=4: all known perturbative results are recovered in a single framework, their apparent conflict is explained while

David S. Dean, Alexandre Lefevre

We consider a tapping dynamics, analogous to that in experiments on granular media, on spin glasses and ferromagnets on random thin graphs. Between taps, zero temperature single spin flip dynamics takes the system to a metastable state. Tapping, corresponds to flipping simultaneously any spin with probability $p$. This dynamics leads to a stationary regime w

V. Rossetto, A. C. Maggs

We perform simulations to numerically study the writhe distribution of a stiff polymer. We compare with analytic results of Bouchiat and Mezard (PRL 80 1556- (1998); cond-mat/9706050).

D. Khomskii

In this paper I discuss the electronic structure and properties of a specific, rather unconventional class of transition metal (TM) compounds, e.g. TM oxides, which formally have unusually high values of the oxidation state, or valence, of TM. In contrast to the typical situation, in this case the charge-transfer gap (excitation energy for the transfer of el

Antonio Puente, Llorenç Serra

Motivated by recent experiments [A. Lorke {\em et al.}, Phys. Rev. Lett.\ {\bf 84}, 2223 (2000)] an analysis of the ground state and far-infrared absorption of two electrons confined in a quantum ring is presented. The height of the repulsive central barrier in the confining potential is shown to influence in an important way the ring properties. The experim

Yu. L. Klimontovich

Despite of remarkable successes the theory of superfluidity, until now we have no a physical explanation of an opportunity of existence of viscousless flow of liquid helium in viscous medium. The existence of superfluid flow becomes possible due to occurence of flicker noise and appropriate residual temporary correlations of the superfluid velocity fluctuati

C. Tannous, A. Fessant, J. Gieraltowski, J. P. Jay

The Landau-Lifshitz (L-L) equation describing the time dependence of the magnetisation vector is numerically integrated fully without any simplifying assumptions in the time domain and the magnetisation time series obtained is Fourier transformed (FFT) to yield the permeability spectrum up to 10 GHz. The non linear results are compared to the experimental re

M. Levanon, D. C. Rapaport

A layer of granular material on a vertically vibrating sawtooth-shaped base exhibits horizontal flow whose speed and direction depend on the parameters specifying the system in a complex manner. Discrete-particle simulations reveal that the induced flow rate varies with height within the granular layer and oppositely directed flows can occur at different lev

Mikio Eto, Yuli V. Nazarov

We investigate the enhancement of the Kondo effect in quantum dots with an even number of electrons, using a scaling method and a mean field theory. We evaluate the Kondo temperature $T_K$ as a function of the energy difference between spin-singlet and triplet states in the dot, $Δ$, and the Zeeman splitting, $E_Z$. If the Zeeman splitting is small, $E_Z \ll

E. V. Tsiper, V. J. Goldman

We have performed an exact diagonalization study of up to N=12 interacting electrons on a disk at filling $ν={1/3}$ for both Coulomb and $V_1$ short-range interaction for which Laughlin wave function is the exact solution. For Coulomb interaction and $N\geq 10$ we find persistent radial oscillations in electron density, which are not captured by the Laughlin

Denis D. Sheka, Boris A. Ivanov, Franz G. Mertens

We study the magnon modes in the presence of a topological soliton in a 2d Heisenberg easy-axis ferromagnet. The problem of magnon scattering on the soliton with arbitrary relation between the soliton radius R and the &#34;magnetic length&#34; Delta_0 is investigated for partial modes with different values of the azimuthal quantum numbers m. Truly local mode

Eli Livne, Baruch Meerson, Pavel V. Sasorov

An ensemble of inelastically colliding grains driven by a vibrating wall in 2D exhibits density clustering. Working in the limit of nearly elastic collisions and employing granular hydrodynamics, we predict, by a marginal stability analysis, a spontaneous symmetry breaking of the extended clustering state (ECS). 2D steady-state solutions found numerically de

Andrea De Martino, Matteo Marsili

We extend and complete recent work concerning the analytic solution of the minority game. Nash equilibria (NE) of the game have been found to be related to the ground states of a disordered hamiltonian with replica symmetry breaking (RSB), signalling the presence of a large number of them. Here we study the number of NE both analytically and numerically. We

J. F. Lara

This article describes the production of primordial He4 nuclei in an inhomogeneous universe. The baryon distribution is spherically symmetric and consists of a high density inner region and a low density outer region. As the temperature decreases neutrons diffuse to the outer region until they are homogeneously distributed, and protons may be redistributed d

M. J. Coe, I. Negueruela, D. A. H. Buckley, N. J. Haigh

We report observations which confirm the identities of the optical counterpart to the transient sources RX J0544.1-7100 and RX J0520.5-6932. The counterparts are suggested to be a B-type stars. Optical data from the observations carried out at ESO and SAAO, together with results from the OGLE data base, are presented. In addition, X-ray data from the RXTE al

Boudewijn F. Roukema

It is often stated that homogeneity and isotropy of the Universe are assumptions of the almost Friedmann-Lema^itre (FL) model (the hot big bang model), inspired from the Copernican Principle. However, only local homogeneity and isotropy are required by the model: multiply connected almost FL models are locally homogeneous and isotropic, but they can be globa

A. Manara, S. Covino, M. Di Martino

We present low resolution reflectance spectra over the wavelength range 5000-10000Åfor 4 asteroids (3 belonging to the Nysa family and one near-Earth asteroid) obtained at the San Pedro Martir Observatory (Mexico) using the 2.1 m telescope. Though the limited wavelength range covered often makes a classification difficult, the analysis of the available data

I. Agudo, J. L. Gomez, J. M. Marti, J. M Ibanez

We present a numerical simulation of the response of an expanding relativistic jet to the ejection of a superluminal component. The simulation has been performed with a relativistic time-dependent hydrodynamical code from which simulated radio maps are computed by integrating the transfer equations for synchrotron radiation. The interaction of the superlumin

Q. D. Tran, D. Lutz, R. Genzel, D. Rigopoulou

We present low resolution mid infrared spectra of 16 ultraluminous infrared galaxies (ULIRGs) obtained with the CVF spectroscopy mode of ISOCAM on board the Infrared Space Observatory ISO. Our sample completes previous ISO spectroscopy of ultra- and hyperluminous infrared galaxies towards higher luminosities. The combined samples cover an infrared luminosity

Marc Freitag, Willy Benz

Stellar collisions have long been envisioned to be of great importance in the center of galaxies where densities of 1e6 stars per cubic pc or higher are attained. Not only can they play a unique dynamical role by modifying stellar masses and orbits, but high velocity disruptive encounters occurring in the vicinity of a massive black hole can also be an occas

Paul P. van der Werf

The properties of starbursts in ultraluminous infrared galaxies are discussed, with particular emphasis on the fueling, the amount of extinction and the intrinsic properties of the nuclear starbursts. It is shown by the example of NGC6240 that the H_2 vibrational lines can be used to measure the rate of gas inflow into the potential well, which is sufficient

F. Pfefferkorn, Th. Boller, P. Rafanelli

We present a catalogue of ROSAT detected sources in the sample of spectroscopically selected Seyfert 1 and Seyfert 2 galaxies of Rafanelli et al. (1995). The catalogue contains 102 Seyfert 1 and 36 Seyfert 2 galaxies. The identification is based on X-ray contour maps overlaid on optical images taken from the Digitized Sky Survey. We have derived the basic sp

Marc Freitag, Willy Benz

We have developed a new numerical code to simulate the joint evolution of a massive black hole (MBH) and a surrounding stellar cluster at the center of a galaxy. The physics treated in the simulations include: 2-body relaxation, stellar collisions (using a large set of &#34;SPH&#34; hydrodynamical simulations) and tidal disruption of stars by the MBH. In par

Ariyeh Maller, Tsafrir Kolatt, Matthias Bartelmann, George R. Blumenthal

We present a new method to determine the total mass-to-neutral gas ratio in Lyman-limits systems. The method exploits the relation between the neutral hydrogen column density and the magnification of background sources due to the weak gravitational lensing that these systems induce. Because weak lensing does not provide a direct measure of mass, one must use

Chris N. Sabbey, Richard G. McMahon, James R. Lewis, Mike J. Irwin

We describe the InfraRed Data Reduction (IRDR) software package, a small ANSI C library of fast image processing routines for automated pipeline reduction of infrared (dithered) observations. We developed the software to satisfy certain design requirements not met in existing packages (e.g., full weight map handling) and to optimize the software for large da

V. A. Bordovitqsyn, V. Ya. Epp, V. G. Bulenok

We suggest a technique for construction of profiles of incoherent pulsar emission using instantaneous angular distribution indicatrix of radiation from relativistic source moving in the neutron star magnetosphere. In the general case the indicatrix depends on the kinematic parameters of radiation source such as velocity and acceleration. The method is illust

Celine Peroux, Lisa J. Storrie-Lombardi, Richard G. McMahon, Mike Irwin

We present high signal-to-noise, 5 A resolution (FWHM) spectra of 66 z \ga 4 bright quasars obtained with the 4 m Cerro Tololo Inter-American Observatory and 4.2 m William Hershel telescopes. The primary goal of these observations was to undertake a new survey for intervening absorption systems detected in the spectra of background quasars. We look for both

D. Gouliermis, K. S. de Boer, S. C. Keller, M. Kontizas

We report about the stellar content and the luminosity and mass functions of three stellar associations and their field located on the north-east edge of the super-bubble LMC 4 in the Large Magellanic Cloud.

Ilse van Bemmel

In this paper I discuss the issue of the so-called 25 micron-peakers, which were discovered with IRAS, and consist almost solely of broad-line radio galaxies. I find that this peak is caused by the absence of colder dust that emits at 60 micron and not by an excess of hot dust, as suggested by the name. On optical images, the 25 micron-peakers show a lack of

J. G. Kirk, R. O. Dendy

Motivated by recent unsuccessful efforts to detect the predicted flux of TeV gamma-rays from supernova remnants, we present a critical examination of the theory on which these predictions are based. Three crucial problems are identified: injection, maximum achievable particle energy and spectral index. In each case significant new advances in understanding h

Hyun Kyu Lee

We discuss the effect of the Poynting flow on the magnetically dominated thin accretion disk, which is simplified to a two-dimensional disk on the equatorial plane. It is shown in the relativistic formulation that the Poynting flux by the rotating magnetic field with Keplerian angular velocity can balance the energy and angular momentum conservation of a ste

Kazuhiro Yamamoto, Hiroaki Nishioka

Feasibility of the geometric test as a probe of the cosmic equation of state of the dark energy is discussed assuming the future 2dF QSO sample. We examine sensitivity of the QSO two-point correlation functions, which are theoretically computed incorporating the light-cone effect and the redshift distortions, as well as the nonlinear effect, to a bias model

B. S. Mason, J. K. Cartwright, S. Padin, T. J. Pearson

The Cosmic Background Imager (CBI) is a 13-element interferometer designed to image intrinsic anisotropies in the cosmic microwave background (CMB) on arcminute scales. A review of the capabilities of the instrument is presented, together with a discussion of observations which have been taken over the past 9 months from the Atacama desert of Chile. We prese

Brian S. Mason, Steven T. Myers, A. C. S. Readhead

We present a determination of the Hubble constant from measurements of the Sunyaev-Zeldovich Effect (SZE) in an orientation-unbiased sample of 7 z < 0.1 galaxy clusters. With improved X-ray models and a more accurate 32-GHz calibration, we obtain H_O = 64+14-11 +/- 14_sys km/s/Mpc. for a standard CDM cosmology, or 66+14-11 +/- 15_sys km/s/Mpc for a flat Lamb

Brian S. Mason, Steven T. Myers, A. C. S. Readhead

We present a determination of the Hubble constant from measurements of the Sunyaev-Zeldovich Effect (SZE) in an orientation-unbiased sample of 7 z < 0.1 galaxy clusters. With improved X-ray models and a more accurate 32-GHz calibration, we obtain H_O = 64+14-11 +/- 14_sys km/s/Mpc. for a standard CDM cosmology, or 66+14-11 +/- 15_sys km/s/Mpc for a flat Lamb

F. W. Stecker

These lectures discuss the mysteries involving the production and extragalactic propagation of ultrahigh energy cosmic rays and suggested possible solutions.

Gergely Harcos

We establish an estimate on sums of shifted products of Fourier coefficients coming from holomorphic or Maass cusp forms of arbitrary level and nebentypus. These sums are analogous to the binary additive divisor sum which has been studied extensively. As an application we derive, extending work of Duke, Friedlander and Iwaniec, a subconvex estimate on the cr

Alex Buchel

N=1^* gauge theories are believed to have fractional instanton contributions in the confining vacua. D3 brane probe computations in gravitation dual of large-N N=2^* gauge theories point to the absence of such contributions in the low energy gauge dynamics. We study fractional instantons in N=2 SU(2) Yang-Mills theory from the field theoretical perspective.

V. Barger, T. Falk, T. Han, J. Jiang

We reexamine large CP-violating phases in the general Minimal Supersymmetric Standard Model, as well as more restricted models. We perform a detailed scan over parameter space to find solutions which satisfy the current experimental limits on the electric dipole moments of the electron, neutron and $^{199}$Hg atom, exploring the allowed configurations of pha

H. Neuberger

Developments during the last eight years have refuted the folklore that chiral symmetries cannot be preserved on the lattice. The mechanism that permits chiral symmetry to coexist with the lattice is quite general and may work in Nature as well. The reconciliation between chiral symmetry and the lattice is likely to revolutionize the field of numerical QCD.

Valery N. Marachevsky

The Casimir energy of a dilute homogeneous nonmagnetic dielectric ball at zero temperature is derived analytically for the first time for an arbitrary physically possible frequency dispersion of dielectric permittivity $ε(iω)$. A microscopic model of dielectrics is considered, divergences are absent in calculations because an average interatomic distance $λ$

M. G. Kozlov, S. G. Porsev, I. I. Tupitsyn

We calculated the parity nonconserving (PNC) 6s -> 7s amplitude in Cs. In the Dirac-Coulomb approximation our result is in a good agreement with other calculations. Breit corrections to the PNC amplitude and to the Stark-induced amplitude $β$ are found to be -0.4% and -1% respectively. The weak charge of $^{133}$Cs is $Q_W=-72.5 \pm 0.7$ in agreement with th

Dvaid Vaknin

X-ray reflectivity and grazing incidence diffraction (XGID) from liquid surfaces are described.

Antonio O. Bouzas

We study the renormalization of normal mixing matrices, which includes hermitian and unitary matrices as particular cases. We give a minimal, multiplicative parametrization of counterterms, and compute the renormalized Lagrangian to one-loop order in several models with N species of fermions, both in on-shell and MS schemes. In on-shell scheme the mass-degen

L. Hufnagel, R. Ketzmerick, T. Kottos, T. Geisel

We demonstrate for various systems that the variance of a wave packet $M(t)\propto t^ν$, can show a {\it superballistic} increase with $2<ν\le3$, for parametrically large time intervals. A model is constructed which explains this phenomenon and its predictions are verified numerically for various disordered and quasi-periodic systems.

H. Päs, T. J. Weiler

We discuss four approaches to the determination of absolute neutrino mass. These are the measurement of the zero-neutrino double beta decay rate, of the tritium decay end-point spectrum, of the cosmic ray spectrum above the GZK cutoff (in the Z-burst model), and the cosmological measurement of the power spectrum governing the CMB and large scale structure. T

Roy Maartens, Christos Tsagas, Carlo Ungarelli

We investigate the influence of cosmic magnetic fields on gravitational wave perturbations, and find exact solutions on large scales. We show that a large-scale magnetic field can generate large-scale non-decaying gravitational waves. In the general case where gravitational waves are generated by other mechanisms, a large-scale magnetic field introduces a ne

S. Ludkovsky, B. Diarra

The non-Archimedean spectral theory and spectral integration is developed. The analog of the Stone theorem is proved. Applications are considered for algebras of operators.

M. A. Kimber, J. Kwiecinski, A. D. Martin

Starting from an unintegrated gluon distribution which satisfies a `unified&#39; equation which embodies both BFKL and DGLAP behaviour, we compute the shadowing corrections to the integrated gluon in the small x domain that will be accessible at the LHC. The corrections are calculated via the Korchegov equation, which incorporates the leading ln(1/x) triple-

Patrick Peter, M. E. X. Guimaraes, V. C. de Andrade

We investigate the nature of ordinary cosmic vortices in some scalar-tensor extensions of gravity. We find solutions for which the dilaton field condenses inside the vortex core. These solutions can be interpreted as raising the degeneracy between the eigenvalues of the effective stress-energy tensor, namely the energy per unit length U and the tension T, by

Dusa McDuff, Jennifer Slimowitz

We use the criteria of Lalonde and McDuff to show that a path that is generated by a generic autonomous Hamiltonian is length minimizing with respect to the Hofer norm among all homotopic paths provided that it induces no non-constant closed trajectories in M. This generalizes a result of Hofer for symplectomorphisms of Euclidean space. The proof for general

Felix Finster, Ines Kath

We consider an asymptotically flat Riemannian spin manifold of positive scalar curvature. An inequality is derived which bounds the Riemann tensor in terms of the total mass and quantifies in which sense curvature must become small when the total mass tends to zero.

F. M. Marques, M. Labiche, N. A. Orr

Three-body correlations in the dissociation of two-neutron halo nuclei are explored using a technique based on intensity interferometry and Dalitz plots. This provides for the combined treatment of both the n-n and core-n interactions in the exit channel. As an example, the breakup of 14Be into 12Be+n+n by Pb and C targets has been analysed and the halo n-n

Katarzyna Sznajd-Weron, Jozef Sznajd

A simple Ising spin model which can describe a mechanism of making a decision in a closed community is proposed. It is shown via standard Monte Carlo simulations that very simple rules lead to rather complicated dynamics and to a power law in the decision time distribution. It is found that a closed community has to evolve either to a dictatorship or a stale

Sutapa Mukherji, Somendra M. Bhattacharjee

We use renormalization group to calculate the reunion and survival exponents of a set of random walkers interacting with a long range $1/r^2$ and a short range interaction. These exponents are used to study the binding-unbinding transition of polymers and the behavior of several quantum problems.

Antonio Campos, Carlos F. Sopuerta

In this work we consider Randall-Sundrum brane-world type scenarios, in which the spacetime is described by a five-dimensional manifold with matter fields confined in a domain wall or three-brane. We present the results of a systematic analysis, using dynamical systems techniques, of the qualitative behaviour of the Friedmann-Lemaitre-Robertson-Walker and th

R. Kenna, C. Pinto, J. C. Sexton

A new method to determine the phase diagram of certain lattice fermionic field theories in the weakly coupled regime is presented. This method involves a new type of weak coupling expansion which is multiplicative rather than additive in nature and allows perturbative calculation of partition function zeroes. Application of the method to the single flavour G

Karyn Le Hur

Charge fluctuations of a large quantum dot coupled to a two-dimensional lead via a single-mode good Quantum Point Contact (QPC) and capacitively coupled to a back-gate, are investigated in the presence of a parallel magnetic field. The Zeeman term induces an asymmetry between transmission probabilities for the spin-up and spin-down channels at the QPC, produ

Gautam Dutta, D. Indumathi, M. V. N. Murthy, G. Rajasekaran

Signatures of neutrino and antineutrino signals from stellar collapse in heavy water detectors are contrasted with those in water detectors. The effects of mixing, especially due to the highly dense matter in the supernova core, are studied. The mixing parameters used are those sets allowed by current understanding of available neutrino data: from solar, atm

Vahé Petrosian

Some clusters of galaxies in addition to thermal bremsstrahlung (TB), emit diffuse radiation from the intercluster medium (ICM) at radio, EUV and hard x-ray (HXR) ranges. The radio radiation is due to synchrotron by relativistic electrons, and the inverse Compton (IC) scattering by the cosmic microwave background radiation of the same electrons is the most n

Alejandro Ayala, Angel Sanchez

We examine the effects that a confining boundary together with hydrodynamical expansion play on two-pion distributions in relativistic heavy-ion collisions. We show that the effects arise from the introduction of further correlations due both to collective motion and the system&#39;s finite size. As is well known, the former leads to a reduction in the appar

Takashi Yamamoto, Masato Koashi, Nobuyuki Imoto

An experimental scheme for concentrating entanglement in partially entangled photon pairs is proposed. In this scheme, two separated parties obtain one maximally entangled photon pair from previously shared two partially entangled photon pairs by local operations and classical communication. A practical realization of the proposed scheme is discussed, which

Balázs Kónya

In this work we have presented a rather general and easy-to-apply method for discrete Hilbert space representation of quantum mechanical Green&#39;s operators. We have shown that if in some discrete Hilbert space basis representation the Hamiltonian takes an infinite symmetric tridiagonal, i.e. Jacobi-matrix form the corresponding Green&#39;s matrix can be c

J. Hiraga, H. Tsunemi, E. Miyata

When an X-ray photon lands into a pixel (event pixel), the primary charge is mainly collected into the event pixel. If the X-ray landing position is sufficiently close to the pixel boundary, the primary charge spills over to the adjacent pixel forming split events. We can easily understand that there are three parameters coupled together; the X-ray landing p

Glenisson de Oliveira, Jan M. L. Martin, Indira K. C. Silwal, Joel F. Liebman

A long-standing controversy concerning the heat of formation of methylenimine has been addressed by means of the W2 (Weizmann-2) ab initio thermochemical approach. Our best calculated values, DeltaHf298(CH2NH)=21.1+/-0.5 kcal/mol and DeltaHf298(CH2NH2+)=179.4+/-0.5 kcal/mol, are in good agreement with the most recent measurements but carry a much smaller unc

A. E. Motter, P. S. Letelier

A fractal method to detect, locate and quantify chaos in multi-dimensional-conservative-closed systems, based on the creation of artificial exits, is presented. The method is invariant under space-time changes of coordinates and can be used to analyse both classical and relativistic Hamiltonian systems of more than two degrees of freedom. As an application o

A. E. Motter, P. S. Letelier

A discussion about dependences of the (fractal) basin boundary dimension with the definition of the basins and the size of the exits is presented for systems with one or more exits. In particular, it is shown that the dimension is largely independent of the choice of the basins, and decreases with the size of the exits. Considering the limit of small exits,

John Etnyre, Robert Ghrist

We consider the class of Beltrami fields (eigenfields of the curl operator) on three-dimensional Riemannian solid tori: such vector fields arise as steady incompressible inviscid fluids and plasmas. Using techniques from contact geometry, we construct an integer-valued index for detecting closed orbits in the flow which are topologically inessential (they ha

S. Berman, Y. Billig, J. Szmigielski

An explicit vertex operator algebra construction is given of a class of irreducible modules for toroidal Lie algebras.

Edgar Martinez-Moro

Association schemes are combinatorial objects that allow us solve problems in several branches of mathematics. They have been used in the study of permutation groups and graphs and also in the design of experiments, coding theory, partition designs etc. In this paper we show some techniques for computing properties of association schemes. The main framework