September 1999 arXiv papers — page 17

Robert Lauter

An important question of theoretical physics is whether sound is able to propagate in vacuums at all and if this is the case, then it must lead to the reinterpretation of one zero-restmass particle which corresponds to vacuum-sound waves. Taking the electron-neutrino as the corresponding particle, its observed non-vanishing rest-energy may only appear for ne

Charles Francis

This is one of a number of papers in which the metric for space-time is defined on the subatomic level by means of the interchange of photons, and constrained to be consistent with radar. It is shown that the discrete nature of particle interactions necessitates a small inherent delay in the radar method, and hence that the resulting geometry is non- Euclide

K. Hagino, G. F. Bertsch

We study an extended Lipkin-Meshkov-Glick model that permits a transition to a deformed phase with a broken continuous symmetry. Unlike simpler models, one sees a persistent zero-frequency Goldstone mode past the transition point into the deformed phase. We found that the RPA formula for the correlation energy provides a useful correction to the Hartree-Fock

C. Bennhold, H. Haberzettl, T. Mart

New SAPHIR p(gamma,K+)Lambda total cross section data show a resonance structure at a total c.m. energy around 1900 MeV. We investigate this feature with an isobar model and find that the structure can be well explained by including a new D_{13} resonance at 1895 MeV. Such a state has been predicted by a relativistic quark model at 1960 MeV with significant

A. V. Afanasjev, P. Ring

The applications of the extensions of relativistic mean field (RMF) theory to the rotating frame, such as cranked relativistic mean field (CRMF) theory and cranked relativistic Hartree-Bogoliubov (CRHB) theory, for the description of superdeformed bands in the $A\sim 60$, 140-150 and 190 mass regions are overviewed and compared briefly with the results obtai

Z. Papadopolos, C. Hohneker, P. Kramer

The tiles of the canonical tilings (of the 3dimensional space) T*(2F) are six tetrahedra. We determine their inflation rules by the projection method.

Robert Wendt

We generalize I. Frenkel's orbital theory for non twisted affine Lie algebras to the case of twisted affine Lie algebras using a character formula for certain non-connected compact Lie groups.

Ivan Mirkovic, Dmitriy Rumynin

We modify the Hochschild $ϕ$-map to construct central extensions of a restricted Lie algebra. Such central extension gives rise to a group scheme which leads to a geometric construction of unrestricted representations. For a classical semisimple Lie algebra, we construct equivariant line bundles whose global sections afford representations with a nilpotent p

Pietro Caputo, Yvan Velenik

We prove existence of a wetting transition for two types of gradient fields: 1) Continuous SOS models in any dimension and 2) Massless Gaussian model in two dimensions. Combined with a recent result showing the absence of such a transition for Gaussian models above two dimensions by Bolthausen et al, this shows in particular that absolute-value and quadratic

Drazen Adamovic

In this note we prove that the vertex operator superalgebras associated to the unitary representations of the N=2 superconformal algebra are rational.

George Siopsis

We discuss absorption of scalars by a distribution of spinning D3-branes. The D3-branes are multi-center solutions of supergravity theory. We solve the wave equation in various cases of supergravity backgrounds in which the equation becomes separable. We show that the absorption coefficients exhibit a universal behavior as functions of the angular momentum q

Jeremy Michelson

Some general aspects of the AdS_2/CFT_1 correspondence, previously discussed in hep-th/9812073, are summarized. The majority of this summary is devoted to the question of where the CFT_1 should live. Almost as a byproduct, the decay---or fragmentation---of AdS_2 is also discussed.

John Ellis, N. E. Mavromatos, Elizabeth Winstanley

We use logarithmic conformal field theory techniques to describe recoil effects in the scattering of two Dirichlet branes in D dimensions. In the particular case that a D1 brane strikes a D3 brane perpendicularly, thereby folding it, we find that the recoil space-time is maximally symmetric, with AdS_3 x E_{D-3} geometry. We comment on the possible applicati

Helmuth Huffel, Gerald Kelnhofer

We review recent results on the derivation of a global path integral density for Yang-Mills theory. Based on a generalization of the stochastic quantization scheme and its geometrical interpretation we first recall how locally a modified Faddeev-Popov path integral density for the quantization of Yang-Mills theory can be derived, the modification consisting

P. Marios Petropoulos

String theory on curved backgrounds has received much attention on account of both its own interest, and of its relation with gauge theories. Despite the progress made in various directions, several quite elementary questions remain unanswered, in particular in the very simple case of three-dimensional anti-de Sitter space. I briefly review these problems.

Hajime Aoki, Satoshi Iso, Hikaru Kawai, Yoshihisa Kitazawa

We show that correlation functions for branched polymers correspond to those for $ϕ^3$ theory with a single mass insertion, not those for the $ϕ^3$ theory themselves, as has been widely believed. In particular, the two-point function behaves as 1/p^4, not as 1/p^2. This behavior is consistent with the fact that the Hausdorff dimension of the branched polymer

Roberto Begliuomini

This Ph.D. thesis reaches two main results. The first one is represented by a detailed study, in Feynman gauge, of the perturbative ${\cal O}(g^4)$ contribution to a space-time Wilson loop, with respect to its (expected) Abelian-like time exponentiation when the temporal side goes to infinity. As soon as we are in dimensions greater than two, the expected be

G. P. Salam, G. Zanderighi

We discuss the issue of interplay between perturbative and non-perturbative phenomena for power corrections to e+e- event shapes.

I. V. Akushevich, H. Anlauf, E. A. Kuraev, P. G. Ratcliffe

The process of electron-positron pair production by linearly polarized photons is used as a polarimeter to perform mobile measurement of linear photon polarization. In the limit of high photon energies, omega, the distributions of the recoil-electron momentum and azimuthal angle do not depend on the photon energy in the laboratory frame. We calculate the pow

J. Ellis, H. Fujii, D. Kharzeev

We use Ward identities of broken scale invariance to infer the amount of scalar glueball--$\bar{q}q$ meson mixing from the ratio of quark and gluon condensates in the QCD vacuum. Assuming dominance by a single scalar state, as suggested by a phase-shift analysis, we find a mixing angle $γ\sim 36^{\circ}$, corresponding to near-maximal mixing of the glueball

Jose Bordes, Chan Hong-Mo, Ricardo Gallego, Tsou Sheung Tsun

Muon-electron conversion in nuclei is considered in the framework of the Dualized Standard Model. The ratio $B_{μ-e}$ of the conversion rate to the total muon capture rate is derived, and computed for several nuclei in a parameter-free calculation using parameters previously determined in different physical contexts. The values obtained all lie within the pr

B. Pötter

We discuss forward jet production data recently published by the H1 and ZEUS collaborations at HERA. We review how several Monte-Carlo models compare to the data. QCD calculations based on the BFKL formalism and on fixed NLO perturbation theory with and without resolved virtual photons are described.

Wojciech Krolikowski

A new lefthanded see-saw mechanism is constructed, implying both the smallness of active-neutrino masses and decoupling of heavy passive neutrinos, similarly to the situation in the case of conventional see-saw. But now, in place of the conventional righthanded neutrinos, the lefthanded sterile neutrinos play the role of heavy passive neutrinos, the righthan

F. Richard

Summary talk given at the International Workshop on Linear Colliders LCWS 99, Sitges (Barcelona), April 28 - May 5, 1999

Yoshiharu Kawamura

We study the magnitudes of soft SUSY breaking parameters in heterotic string models with anomalous U(1) symmetry. In most cases, D-term contribution to soft scalar masses is expected to be comparable to or dominant over other contributions provided that supersymmetry breaking is mediated by the gravitational interaction and/or an anomalous U(1) symmetry and

John P. Ralston, Pankaj Jain, Bijoy Kundu, Jim Samuelsson

Color transparency is a prediction of perturbative QCD. Yet detailed calculations have been lacking, and aspects of the required factorization have been controversial. We report on the first complete calculations entirely within a perturbative QCD framework. We also comment on the underlying factorization method and assumptions.

S. Sharpe, N. Shoresh

We discuss the importance of using partially quenched theories with three degenerate quarks for extrapolating to QCD, and present some relevant results from chiral perturbation theory.

Vladimir K. Petrov

Cooled down and diluted quark-gluon matter is considered. A possibility of condensation of multiquark clusters with zero N-alities is discussed.

K. Orginos, R. Sugar, D. Toussaint

We study improved Kogut-Susskind fermion actions focusing on flavor symmetry restoration. Several variants of fat actions suitable for dynamical simulations are considered, including an action with no tree level order a-squared errors. The spectrum of all the pions is computed and used as a measure of flavor symmetry violation. Finally, the Naik term is intr

J-R. Cudell, A. Le Yaouanc, C. Pittori

We analyse available data on the quark pseudoscalar vertex and extract the contribution og the Goldstone boson pole. The strength of the pole is found to be quite large at presently accessible scales. We draw the important consequences of this finding for the various definitions of quark masses.

Andreas S. Kronfeld

It is shown that certain double ratios introduced for computing semileptonic form factors are accurate to order $1/m_Q^2$, even when the action and current are accurate to order $1/m_Q$.

J. Jersak, T. Neuhaus, H. Pfeiffer

In the pure U(1) lattice gauge theory with the Villain action we find that the monopole mass in the Coulomb phase and the monopole condensate in the confinement phase scale according to simple power laws. This holds outside the coupling region in which on finite toroidal lattices the metastability phenomena occur. A natural explanation of the observed accura

C. Bernard, T. DeGrand

We discuss weak coupling perturbation theory for lattice actions in which the fermions couple to smeared gauge links. The normally large integrals that appear in lattice perturbation theory are drastically reduced. Even without detailed calculation, it is easy to determine to good accuracy the scale of the logarithms that appear in cases where an anomalous d

Oliver Baer, Isabel Campos

As first realized by Witten an SU(2) gauge theory coupled to a single Weyl fermion suffers from a global anomaly. This problem is addressed here in the context of the recent developments on chiral gauge theories on the lattice. We find Witten's anomaly manifests in the impossibility of defining globally a fermion measure that reproduces the proper contin

L3 Collaboration

Recent theories propose that quantum gravity effects may be observable at LEP energies via gravitons that couple to Standard Model particles and propagate into extra spatial dimensions. The associated production of a graviton and a photon is searched for as well as the effects of virtual graviton exchange in the processes: e+e- -> gamma gamma, ZZ, WW, mu mu,

L3 Collaboration

We measure the masses, decay widths and relative production rate of orbitally excited B mesons using 1.25 million hadronic Z decays recorded by the L3 detector. B-meson candidates are inclusively reconstructed and combined with charged pions produced at the primary event vertex. An excess of events above the expected background in the Bπmass spectrum in the

Z. Ya. Sadygov, M. K. Suleimanov, T. Yu. Bokova

Physical principles of performance and main characteristics of a novel avalanche photodetector developed on the basis of MOS(metal-oxide-silicon) technology is presented. The photodetector contains a semitransparent gate electrode and a drain contact to provide a drift of multiplicated charge carriers along the semiconductor surface. A high gain(more than 10

Angela Barbaro-Galtieri

We summarize recent measurements made at the Tevatron Collider using top event candidates. Cross section and mass measurements are discussed in a separate contribution to these Proceedings. Here we report on studies of the top P$_T$ distribution in $\ttbar$ production and studies of single top production. Properties of top decays examined are: BF($t \into Wb

M. N. Achasov, V. M. Aulchenko, S. E. Baru, K. I. Beloborodov

The Spherical Neutral Detector (SND) operates at VEPP-2M collider in Novosibirsk studying e^+e^- annihilation in the energy range up to 1.4 GeV. Detector consists of a fine granulated spherical scintillation calorimeter with 1632 NaI(Tl) crystals, two cylindrical drift chambers with 10 layers of sense wires, and a muon system made of streamer tubes and plast

J. Fernando Barbero, Madhavan Varadarajan

We show that the recent claim that the 2+1 dimensional Ashtekar formulation for General Relativity has a finite number of physical degrees of freedom is not correct.

H. Nikolic

A local observer can measure only the values of fields at the point of his own position. By exploring the coordinate transformation between two Fermi frames, it is shown that two observers, having the same instantaneous position and velocity, will observe the same values of covariant fields at their common instantaneous position, even if they have different

I. Lovas

The question whether gravitational waves are quantised or not can in principle be answered by the help of correlation measurements. If the gravitational waves are quantised and they are generated by the change of the background metrics then they can be in squeezed state. In a sqeezed state there is a correlation between the phase of the wave and the quantum

Georg M. Bruun, Charles W. Clark

We investigate theoretically the properties of an ideal trapped gas in a time-dependent harmonic potential. Using a scaling formalism, we are able to present simple analytical results for two important classes of experiments: free expansion of the gas upon release of the trap; and the response of the gas to a harmonic modulation of the trapping potential is

J. E. Williams, M. J. Holland

The burgeoning field of Bose-Einstein condensation in dilute alkali and hydrogen gases has stimulated a great deal of research into the statistical physics of weakly interacting quantum degenerate systems. The recent experiments offer the possibility for exploring fundamental properties of low temperature physics in a very controllable and accessible way. On

J. M. Polson, E. Trizac, S. Pronk, D. Frenkel

We analyse the finite-size corrections to the free energy of crystals with a fixed center of mass. When we explicitly correct for the leading ($\ln N/N$) corrections, the remaining free energy is found to depend linearly on 1/N. Extrapolating to the thermodynamic limit ($N\to\infty$), we estimate the free energy of a defect free crystal of particles interact

G. A. Raggio

We make some simple observations on basic issues pertaining to thermostatistical formalisms.

P. Prelovsek, M. Long, T. Markez, X. Zotos

The Hall constant R_H in a tight-binding model of correlated electrons on a ladder at T=0 is expressed in terms of derivatives of the ground state energy with respect to external magnetic and electric fields. This novel method is used for the analysis of the t-J model on finite size ladders. It is found that for a single hole R_H is hole-like and close to th

M. A. Novotny

An overview of advanced dynamical algorithms capable of spanning the widely disparate time scales that govern the decay of metastable phases in discrete spin models is presented. The algorithms discussed include constrained transfer-matrix, Monte Carlo with Absorbing Markov Chains (MCAMC), and projective dynamics (PD) methods. The strengths and weaknesses of

Fabrizio Illuminati, Patrick Navez, Martin Wilkens

We derive exact thermodynamic identities relating the average number of condensed atoms and the root-mean-square fluctuations determined in different statistical ensembles for the weakly interacting Bose gas confined in a box. This is achieved by introducing the concept of {\it auxiliary partition functions} for model Hamiltonians that do conserve the total

P. H. M. Van Loosdrecht, J. Zeman, G. Martinez, M. J. KonstantinoviĆ

Some of the properties of the low-dimensional electronically correlated materials \cgo and \nvo are discussed. The emphasis lies on recent results obtained using Raman scattering and optical absorption spectroscopy as a function of temperature, magnetic field and hydrostatic pressure.

K. W. Kehr, Z. Koza

The hopping motion of lattice gases through potentials without mirror-reflection symmetry is investigated under various bias conditions. The model of 2 particles on a ring with 4 sites is solved explicitly; the resulting current in a sawtooth potential is discussed. The current of lattice gases in extended systems consisting of periodic repetitions of segmen

Domenico Gazzillo, Achille Giacometti, F. Carsughi

Approximate scattering functions for polydisperse ionic colloidal fluids are obtained by a corresponding states approach. This assumes that all pair correlation functions $g_{αβ}(r)$ of a polydisperse fluid are conformal to those of an appropriate monodisperse binary fluid (reference system) and can be generated from them by scaling transformations. The corr

Alexander Altland, B D Simons

The random flux model (defined here as a model of lattice fermions hopping under the influence of maximally random link disorder) is analysed field theoretically. It is shown that the long range physics of the model is described by the supersymmetric version of a field theory that has been derived earlier in connection with lattice fermions subject to weak r

Maria Markosova

The absorbing "ricepile" model with stochastic toppling rules has been numerically studied. Local limited, local unlimited, nonlocal limited and nonlocal unlimited versions of the absorbing model have been investigated. Transport properties and different dynamical regimes of all of the models have been analysed, from the point of view of self organiz

Denis Richard, Elie Raphael

The effect of viscosity on the wave resistance experienced by a 2d perturbation moving at uniform velocity over the free surface of a fluid is investigated. The analysis is based on Rayleigh's linearized theory of capillary-gravity waves. It is shown in particular that the wave resistance remains bounded as the velocity of the perturbation approches the

T. Mertelj, D. Kuscer, M. Kosec, D. Mihailovic

Photoinduced IR absorption was measured in (La(1-x)Sr(x)Mn)(1-δ)O3. A midinfrared peak centered at ~ 5000 cm$^{-1}$ was observed in the x=0 antiferromagnetic sample. The peak diminishes and softens as hole doping is increased. The origin of the photoinduced absorption peak is atributted to the photon assisted hopping of anti-Jahn-Teller polarons formed by ph

M Moser, A Prets, W L Spitzer

A rigorous derivation of macroscopic spin-wave equations is demonstrated. We introduce a macroscopic mean-field limit and derive the so-called Landau-Lifshitz equations for spin waves. We first discuss the ferromagnetic Heisenberg model at T=0 and finally extend our analysis to general spin hamiltonians for the same class of ferromagnetic ground states.

Subhradip Ghosh, Abhijit Mookerjee

Crystalline Co$_{x}$Cu$_{1-x}$ alloys show interesting magnetic behavior over the entire concentration regime. We here present a fully self- consistent first principles electronic structure studies of the electronic structure and magnetic properties of the system.We present results for the variation of density of states, magnetic moment,spin susceptibility a

L. Bellon, S. Ciliberto, C. Laroche

Temperature cycling is used to study of aging properties of PMMA dielectric constant. If a negative temperature cycle is applied during the aging time the relaxation dynamics is just delayed for a time equal to the cycle period. In contrast this time shifting procedure cannot be applied to positive temperature cycles . The analogies and differences with simi

Francis W. Starr, C. Austen Angell, Robin J. Speedy, H. Eugene Stanley

Controversy exists regarding the possible existence of a transition between the liquid and glassy states of water. Here we use experimental measurements of the entropy, specific heat, and enthalpy of both liquid and glassy water to construct thermodynamically-plausible forms of the entropy in the difficult-to-probe region between 150 K and 236 K. We assume t

Ben O'Shaughnessy, Dimitrios Vavylonis

We study irreversible A-B reaction kinetics at a fixed interface separating two immiscible bulk phases, A and B. We consider general dynamical exponent $z$, where $x_t\sim t^{1/z}$ is the rms diffusion distance after time $t$. At short times the number of reactions per unit area, $R_t$, is {\em 2nd order} in the far-field reactant densities $n_A^{\infty},n_B

C. O. Dorso, A. Bonasera

We calculate the maximal Lyapunov exponent, the generalized entropies, the asymptotic distance between nearby trajectories and the fractal dimensions for a finite two dimensional system at different initial excitation energies. We show that these quantities have a maximum at about the same excitation energy. The presence of this maximum indicates the transit

Will Saunders, Seb Oliver, Oliver Keeble, Michael Rowan-Robinson

We present the catalogue and redshift data for the PSCz survey of 15,000 IRAS galaxies over 84% of the sky. The uniformity, completeness and data quality are assessed, and guidelines and caveats for its use are given.

Will Saunders, Enzo Branchini, Luis Teodoro, Alan Heavens

We present the results for the predicted density and peculiar velocity fields and the dipole from the PSCz survey of 15,000 IRAS galaxies over 84% of the sky. We find a significant component to the dipole arising between 6000 and 15,000 km/s, but no significant component from greater distances. The misalignment with the CMB is 20 degrees. The most remarkable

Bradley E. Schaefer, Jeremy R. King, Constantine P. Deliyannis

Short duration flares are well known to occur on cool main-sequence stars as well as on many types of `exotic' stars. Ordinary main-sequence stars are usually pictured as being static on time scales of millions or billions of years. Our sun has occasional flares involving up to $\sim 10^{31}$ ergs which produce optical brightenings too small in amplitude

Eric P. Rubenstein, Bradley E. Schaefer

Stellar flares with ${10^2-10^7}$ times more energy than the largest solar flare have been detected from 9 normal F and G main sequence stars (Schaefer, King & Deliyannis 1999). These superflares have durations of hours to days and are visible from at least x-ray to optical frequencies. The absence of world-spanning aurorae in historical records and of anoma

V. Charmandaris, O. Laurent, I. F. Mirabel, P. Gallais

We present results on mid-IR (5--16micron) spectral imaging of a sequence of interacting galaxies, observed by ISOCAM. The galaxies are part of the well known Toomre's ``merger sequence'' which was defined as a sample of galaxies depicting progressive snapshots in the time evolution of a merging event. To trace the intensity of the radiation fiel

S. Gottloeber, A. Klypin, A. V. Kravtsov, V. Turchaninov

Using high resolution N-body simulations we have studied the formation and evolution of clusters and groups in a LCDM cosmological model. Groups of galaxies have been formed already before z=4. The total number of small bound systems and the total number of galaxies in these small systems rapidly decreases after z=1.5. The fraction of isolated galaxies remai

Cristina C. Popescu, Ulrich Hopp, Michael R. Rosa

We present a study of the star formation properties of a sample of emission line galaxies (ELGs) with respect to their environment. This study is part of a bigger project that aimed to find galaxies in voids and to investigate the large scale structure of the ELGs. A survey for ELGs was therefore conducted with the result that 16 galaxies have been found in

Andrew Young, Lawrence Rudnick, Debora M. Katz-Stone, Aileen A. O'Donoghue

Color-color diagrams have been useful in studying the spectral shapes in radio galaxies. At the workshop we presented color-color diagrams for two wide-angle tails, 1231+674 and 1433+553, and found that the standard aging models do not adequately represent the observed data. Although the JP and KP models can explain some of the observed points in the color-c

John M. Blondin

The effects of binary tidal forces on transport within an accretion disk are studied with a time-dependent hydrodynamical model of a two-dimensional isothermal accretion disk. Tidal forces quickly truncate the accretion disk to radii of order half the average radius of the Roche lobe, and excite a two-armed spiral wave that remains stationary in the rotating

Kohji Molikawa, Makoto Hattori, Jean-Paul Kneib, Kazuyuki Yamashita

We present ROSAT HRI X-ray observations of all the galaxy clusters in the Le Fèvre et al. arc survey sample in order to study the spatial distribution of the intra-cluster medium, and examine the expected number of giant luminous arcs for the sample using two spherically symmetric lens models constrained by our X-ray data.

M. Boettcher

The current status of leptonic jet models for gamma-ray blazars is reviewed. Differences between the quasar and BL-Lac subclasses of blazars may be understood in terms of the dominance of different radiation mechanisms in the gamma-ray regime. Spectral variability patterns of different blazar subclasses appear to be significantly different and require differ

Carlos De Breuck, Wil van Breugel, Dante Minniti, George Miley

We present optical, infrared and radio data of the z=4.11 radio galaxy TN J1338-1942, including an intermediate resolution spectrum obtained with FORS1on the VLT Antu telescope. TN J1338-1942 was the first z>4 radio galaxy to be discovered in the southern hemisphere and is one of the most luminous Ly-alpha objects in its class. The Ly-alpha and rest-frame op

S. Doeleman, T. P. Krichbaum

While VLBI experiments at 3mm are nowadays fairly standard, VLBI at 1mm still is technically difficult. Here we summarize the results from previous VLBI pilot experiments at 1.3mm. These included antennas at IRAM (Pico Veleta, Plateau de Bure) and more recently the Heinrich Hertz telescope on Mt. Graham, Arizona.

T. P. Krichbaum, A. Witzel, J. A. Zensus

We report results from 3mm-VLBI observations of 3C273 and 3C454.3 during the period 1994-1997. In both sources the images show superluminal motion in feature-rich jets. Due to the improved uv-coverage in the later experiments, the jets can be followed further out than previously. Comparision with maps obtained at longer wavelengths allows to determine spectr

Chul-Sung Choi, Tadayasu Dotani, P. C. Agrawal

We report results from analysis of the X-ray observations of AE Aqr, made with Ginga in June 1988 and with ASCA in October 1995. Pulsations are detected clearly with a sinusoidal pulse profile with periods of $33.076\pm0.001$ s (Ginga) and $33.077\pm0.003$ s (ASCA)\@. The pulse amplitude is relatively small and the modulated flux remains nearly constant desp

Will Saunders, Kenton d'Mellow, Brent Tully, Bahram Mobasher

We have extended the PSCz to cover 93% of the sky, the practical limit for any catalogue based on the Point Source Catalog. The galaxy identifications are complete, and the core of the Great Attractor is quantitatively mapped for the first time. We discuss the likely effect of the increased sky coverage on the IRAS dipole.

Chul-Sung Choi, Insu Yi

AE Aqr is an unusual close binary system with a very short white dwarf spin period, a high spin-down rate, a relatively low quiescent luminosity, and clear pulse signals. The exact nature of the large spin-down power has not been well explained mainly due to the fact that the observed luminosities in various energy ranges are much lower than the spin-down po

M. Amenomori

The Tibet experiment, operating at Yangbajing (4,300 m above sea level), is the lowest energy air shower array and the new high density array constructed in 1996 has sensitivity to $γ$-ray air showers at energies as low as 3 TeV. With this new array, the Crab Nebula was observed in multi-TeV $γ$-rays and a signal was detected at the 5.5 $σ$ level. We also ob

Elaine M. Sadler, V. J. McIntyre, C. A. Jackson, R. D. Cannon

We present the first results from a study of the radio continuum properties of galaxies in the 2dF Galaxy Redshift Survey, based on thirty 2dF fields covering a total area of about 100 square degrees. About 1.5% of galaxies with b(J) < 19.4 mag are detected as radio continuum sources in the NRAO VLA Sky Survey (NVSS). Of these, roughly 40% are star-forming g

Yoshiaki Taniguchi, Neil Trentham, Satoru Ikeuchi

We propose and investigate a new formation mechanism for globular clusters in which they form within molecular clouds that are formed in the shocked regions created by galactic winds driven by successive supernova explosions shortly after the initial burst of massive star formation in the galactic centers. The globular clusters have a radial distribution tha

Marcos Rigol, Alejandro Cabo

A particular initial state for the construction of the perturbative expansion of QCD is investigated. It is formed as a coherent superposition of zero momentum gluon pairs and shows Lorentz as well as global SU(3) symmetries. It follows that the gluon and ghost propagators determined by it, coincides with the ones used in an alternative of the usual perturba

Vesselin Petkov

The paper pursues two aims. First, to revisit the classical electromagnetic mass theory and develop it further by making use of a corollary of general relativity - that the propagation of light in non-inertial reference frames is anisotropic. Second, to show that the same type of acceleration-dependent self-interaction effects that give rise to the inertia a

Martin White, Wayne Hu

We describe an efficient algorithm for calculating the statistics of weak lensing by large-scale structure based on a tiled set of independent particle-mesh N-body simulations which telescope in resolution along the line of sight. This efficiency allows us to predict not only the mean properties of lensing observables such as the power spectrum, skewness and

Erik Aurell, Duccio Fanelli, Paolo Muratore-Ginanneschi

The dynamics of a one-dimensional self-gravitating medium, with initial density almost uniform is studied. Numerical experiments are performed with ordered and with Gaussian random initial conditions. The phase space portraits are shown to be qualitatively similar to shock waves, in particular with initial conditions of Brownian type. The PDF of the mass dis

Egor Babaev

We briefly review the nonlinear sigma model approach for the subject of increasing interest: &#34;two-step&#34; phase transitions in the Gross-Neveu and the modified Nambu-Jona-Lasinio models at low $N$ and condensation from pseudogap phase in strong-coupling superconductors. Recent success in describing &#34;Bose-type&#34; superconductors that possess two c

Sandhya M. Rao, David A. Turnshek

We report results on the incidence and cosmological mass density of damped Lyman-alpha (DLA) systems at redshifts less that 1.65. We used HST and an efficient non-traditional (but unbiased) survey technique to discover DLA systems at redshifts z<1.65, where we observe the Lyman-alpha line in known MgII absorption-line systems. We uncovered 14 DLA lines inclu

Sedigheh Deldar

The string tensions for fundamental and a variety of representations: adjoint, 6, 10, 15-symmetric, 15-antisymmetric, and 27 have been measured in pure gauge SU(3). The calculations have been done on anisotropic lattices, using an $O(a^2)$ tadpole improved action. A range of lattice spacings and lattice sizes has been used to control finite volume and finite

Hamid Kharraziha, Stefano Moretti

We present several implementations of the Metropolis method, an adaptive Monte Carlo algorithm, which allow for the calculation of multi-dimensional integrals over arbitrary on-shell four-momentum phase space. The Metropolis technique reveals itself very suitable for the treatment of high energy processes in particle physics, particularly when the number of

Michael C. Ogilvie, Peter N. Meisinger

We describe the SU(3) deconfinement transition using Landau-Ginsberg theory. Drawing on perturbation theory and symmetry principles, we construct the free energy as a function of temperature and the Polyakov loop. Once the two adjustable parameters of the model are fixed, the pressure p, energy epsilon and Polyakov loop expectation value P_F are calculable f

Gary T. Horowitz, Veronika E. Hubeny

We investigate the decay of a scalar field outside a Schwarzschild anti de Sitter black hole. This is determined by computing the complex frequencies associated with quasinormal modes. There are qualitative differences from the asymptotically flat case, even in the limit of small black holes. In particular, for a given angular dependence, the decay is always

A. Gasparian, J. Haidenbauer, C. Hanhart, L. Kondratyuk

The reactions $pp\to pΛK^+$ and $pp\to pΣ^0K^+$ are studied near their thresholds. The strangeness production process is described by the $π$- and $K$ exchange mechanisms. Effects from the final state interaction in the hyperon-nucleon system are taken into account rigorously. It is found that the $Λ$ production is dominated by $K$ exchange whereas $K$- as w

O. M. Auslaender, A. Yacoby, R. de Picciotto, K. W. Baldwin

We have measured the low temperature conductance of a one-dimensional island embedded in a single mode quantum wire. The quantum wire is fabricated using the cleaved edge overgrowth technique and the tunneling is through a single state of the island. Our results show that while the resonance line shape fits the derivative of the Fermi function the intrinsic

Alessandra Feo, Robert Kirchner, Silke Luckmann, Istvan Montvay

In a numerical Monte Carlo simulation of SU(3) Yang-Mills theory with dynamical gluinos we have investigated the behaviour of the expectation value of the scalar and pseudoscalar gluino condensates in order to determine the phase structure. Preliminary results are presented as a function of the hopping parameter.

Gregory Brown, M. A. Novotny, Per Arne Rikvold

Numerical integration of a stochastic Landau-Lifshitz-Gilbert equation is used to study dynamic processes in single-domain nanoscale magnets at nonzero temperatures. Special attention is given to including thermal fluctuations as a Langevin term, and the Fast Multipole Method is used to calculate dipole-dipole interactions. It is feasible to simulate these d

K. Ogure, J. Sato

We show that the evolution equation of the effective potential in the auxiliary mass method corresponds to a leading approximation of a certain series. This series is derived from an evolution equation of an effective action using a derivative expansion. We derived an expression of the next-to-leading approximation of the evolution equation, which is a simul

R. Quian Quiroga, J. Arnhold, K. Lehnertz, P. Grassberger

Recently, renormalized entropy was proposed as a novel measure of relative entropy (P. Saparin et al., Chaos, Solitons & Fractals 4, 1907 (1994)) and applied to several physiological time sequences, including EEGs of patients with epilepsy. We show here that this measure is just a modified Kullback-Leibler (K-L) relative entropy, and it gives similar numeric

Doron Cohen, Felix M. Izrailev, Tsampikos Kottos

We apply random-matrix-theory (RMT) to the analysis of evolution of wavepackets in energy space. We study the crossover from ballistic behavior to saturation, the possibility of having an intermediate diffusive behavior, and the feasibility of strong localization effect. Both theoretical considerations and numerical results are presented. Using quantal-class

Doron Cohen, Eric J. Heller

We consider a classically chaotic system that is described by an Hamiltonian $H(Q,P;x)$ where x is a constant parameter. Our main interest is in the case of a gas-particle inside a cavity, where $x$ controls a deformation of the boundary or the position of a `piston&#39;. The quantum-eigenstates of the system are $|n(x)>$. We describe how the parametric kern