March 1999 arXiv papers — page 7

C. Josserand

A 2-D version of the asymmetric exclusion model for granular sheared flows is presented. The velocity profile exhibits two qualitatively different behaviors, dependent on control parameters. For low friction, the velocity profile follows an exponential decay while for large friction the profile is more accurately represented by a Gaussian law. The phase tran

Kristin Schleich, Donald Witt

It is well known that in four or more dimensions, there exist exotic manifolds; manifolds that are homeomorphic but not diffeomorphic to each other. More precisely, exotic manifolds are the same topological manifold but have inequivalent differentiable structures. This situation is in contrast to the uniqueness of the differentiable structure on topological

Roberto Laura, Rodolfo M. Id Betan

The formalism of subdynamics is extended to the functional approach of quantum systems, and used for the Friedrichs model, in which diagonal singularities in states and observables are included. We compute in this approach the generalized eigenvectors and eigenvalues of the Liouvulle-Von Newmann operator, using an iterative scheme. As complex generalized eig

A. Marchewka, Z. Schuss

Discontinuous initial wave functions or wave functions with discontintuous derivative and with bounded support arise in a natural way in various situations in physics, in particular in measurement theory. The propagation of such initial wave functions is not well described by the Schrödinger current which vanishes on the boundary of the support of the wave f

Sixia Yu, Chang-Pu Sun

The search operation for a marked state by means of Grover's quantum searching algorithm is shown to be an element of group SU(2) which acts on a 2-dimensional space spanned by the marked state and the unmarked collective state. Based on this underlying structure, those exact bounds of the steps in various quantum search algorithms are obtained in a quit

Kuniharu Kubodera

Effective field theory is considered to provide a highly useful framework for connecting nuclear physics with the symmetries and dynamics of the underlying theory of strong interactions, QCD. Of many issues that are of great current interest in this domain, I concentrate here on two: (1) A new class of ab initio calculations of obsevables in two-nucleon syst

Vladimir I. Kukulin, V. N. Pomerantsev, Amand Faessler

A complete version of the Moscow NN potential model is presented. The excellent description for all essential partial waves has been found in the energy range 0 -- 350 MeV. The one-channel version of the model includes the orthogonality condition to most symmetric six-quark states in all lowest partial waves and thus, from this point of view, the model gener

J. Providencia, H. Walliser, H. Weigel

The soliton formation is considered in the Nambu-Jona-Lasinio model with local four quark interaction and various schemes to regularize the energy contribution of the polarized vacuum. No additional constraints are admitted in order to stabilize the soliton. While solitons are unstable in the proper-time regularized version the three momentum cut-off regular

A. L. Barabanov

The hyperfine effect in muon capture rate is analyzed with taking into account of the second-order terms in 1/M in the non-relativistic Hamiltonian. It is shown that in the situation of the dominance of the squared first-order terms the interference of zero-order and second-order terms has no significant influence. General expression for neutrino (recoil nuc

N. P. Landsman

For any Lie groupoid $G$, the vector bundle $g^*$ dual to the associated Lie algebroid $g$ is canonically a Poisson manifold. The (reduced) C*-algebra of $G$ (as defined by A. Connes) is shown to be a strict quantization (in the sense of M. Rieffel) of $g^*$. This is proved using a generalization of Weyl's quantization prescription on flat space. Many ot

Adrian Patrascioiu, Erhard Seiler

The commonly accepted belief that non-Abelian and Abelian models are different because of the presence/absence of instantons and/or perturbative asymptotic freedom is analyzed from a historical perspective. The presentation covers the major developments which brought about this dogma, as well as all the supportive evidence produced since. For a model possess

J. Marion, K. Valavane

The notion of good spectral triple is initiated. We prove firstly that any regular spectral triple may be embedded in a good spectral triple, so that, in non-commutative geometry, we can restricts to deal only with good spectral triples. Given a good spectral triple K=(A,H,D), we prove that A is naturally endowed with a topology, called the K-topology, makin

Andrew Granville, K. Soundararajan

Assuming the Generalized Riemann Hypothesis, the authors study when a character sum over all n <= x is o(x); they show that this holds if log x / log log q -> infinity and q -> infinity (q is the size of the finite field).

Michael Farber

In a recent joint work with V. Turaev (cf. math.DG/9810114) we defined a new concept of combinatorial torsion which we called absolute torsion. Compared with the classical Reidemeister torsion it has the advantage of having a well-defined sign. Also, the absolute torsion is defined for arbitrary orientable flat vector bundles, and not only for unimodular one

Michael Farber

Torsion objects of von Neumann categories describe the phenomen &#34;spectrum near zero&#34; discovered by S. Novikov and M. Shubin. In this paper we classify Hermitian forms on torsion objects of a finite von Neumann category. We prove that any such form can be represented as a discriminant form of a degenerate Hermitian form on a projective module. We also

Y. A. Abramovich, C. D. Aliprantis, O. Burkinshaw, A. W. Wickstead

Answering in the affirmative a question posed in [Y.A.Abramovich, C.D.Aliprantis and O.Burkinshaw, Multiplication and compact-friendly operators, Positivity 1 (1997), 171--180], we prove that a positive multiplication operator on any $L_p$-space (resp. on a $C(Ω)$-space) is compact-friendly if and only if the multiplier is constant on a set of positive measu

James W. Anderson

We show that there exist infinitely many commensurability classes of finite volume hyperbolic 3-manifolds whose fundamental group contains a subgroup which is locally free but not free. The main technical tool is the fact that a collection of hyperbolic 3-manifolds of bounded volume contains infinitely many commensurability classes. The result then by an app

Michael Farber

The paper suggests new topological lower bounds for the number of zeros of closed 1-forms within a given cohomology class. The main new technical tool is the deformation complex, which allows to pass to a singular limit and reduce the original problem with a closed 1-form to a traditional problem with a Morse function. We show by examples that the suggested

Daniel C. Cohen

We relate the cohomology of the Orlik-Solomon algebra of a discriminantal arrangement to the local system cohomology of the complement. The Orlik-Solomon algebra of such an arrangement (viewed as a complex) is shown to be a linear approximation of a complex arising from the fundamental group of the complement, the cohomology of which is isomorphic to that of

Michael Joswig, G&#34;unter M. Ziegler

Neighborly cubical polytopes exist: for any $n\ge d\ge 2r+2$, there is a cubical convex d-polytope $C^n_d$ whose $r$-skeleton is combinatorially equivalent to that of the $n$-dimensional cube. This solves a problem of Babson, Billera & Chan. Kalai conjectured that the boundary $\partial C^n_d$ of a neighborly cubical polytope $C^n_d$ maximizes the $f$-vector

Robert C. Myers

We discuss various approaches to extracting the full stress-energy tensor of the conformal field theory from the corresponding supergravity solutions, within the framework of the Maldacena conjecture. This provides a more refined probe of the AdS/CFT correspondence. We apply these techniques in considering the Casimir energy of the conformal field theory on

C. Klimcik

A noncommutative associative algebra of N=2 fuzzy supersphere is introduced. It turns out to possess a nontrivial automorphism which relates twisted chiral to twisted anti-chiral superfields and hence makes possible to construct noncommutative nonlinear $\si$-models with extended supersymmetry.

C. Adam

In a recent paper, Ekstrand proposed a simple expression from which covariant anomaly, covariant Schwinger term and higher covariant chain terms may be computed. We comment on the relation of his result to the earlier work of Tsutsui.

Nobuhito Maru

We consider \caln=1 supersymmetric SO(N) gauge theory with a symmetric traceless tensor. This theory saturates &#39;t Hooft matching conditions at the origin of the moduli space. This naively suggests a confining phase, but Brodie, Cho, and Intriligator have conjectured that the origin of the moduli space is in a Non-Abelian Coulomb phase. We construct a dua

Ziemowit Popowicz

The general method of the supersymmetrization of the soliton equations with the odd (bi) hamiltonian structure is established. New version of the supersymmetric N=2,4 (Modified) Korteweg de Vries equation is given, as an example. The second odd Hamiltonian operator of the SUSY KdV equation generates the odd N=2,4 SUSY Virasoro - like algebra.

Eric D&#39;Hoker, Daniel Z. Freedman, Samir D. Mathur, Alec Matusis

The graviton exchange diagram for the correlation function of arbitrary scalar operators is evaluated in anti-de Sitter space, AdS(d+1). This enables us to complete the computation of the 4-point amplitudes of dilaton and axion fields in IIB supergravity on AdS5 X S5. By the AdS/CFT correspondence, we obtain the 4-point functions of the marginal operators Tr

R. Amorim, J. Barcelos-Neto

We make a systematic development of the non-Abelian formulation of two-form gauge fields with topological coupling with the Yang-Mills one-form connection. An analysis of the gauge structure, reducibility conditions and physical degrees of freedom is presented. We employ the Batalin-Vilkovisky formalism to quantize the resulting theory.

M. A. Valle Basagoiti

Starting from the kinetic formulation of the hard thermal loop effective theory, we have (re)derived the collision terms for soft modes of order $g^2 T \log(1/g)$ by averaging the statistical fluctuations in the plasma.

Alakabha Datta

We study flavor changing processes $Υ\to B/{\bar B} X_s$ and $J/ψ\to D/{\bar D} X_u$ in the B factories and the Tau-Charm factories. In the standard model, these processes are predicted to be unobservable, so they serve as a probe of the new physics. We first perform a model independent analysis, then examine the predictions of models; such as top color mode

Riccardo Barbieri, Paolo Creminelli, Andrea Romanino

We extend a previously developed description of the flavour parameters in the charged fermion sector, based on a U(2) flavour symmetry, to include two main features of the neutrino sector seemingly implied by recent data: a large mixing angle $θ_{μτ}$ and a large hierarchy in the neutrino squared mass differences. A unified description of quark and lepton ma

L. Alvarez-Gaume, C. Kounnas, S. Lola, P. Pavlopoulos

Motivated by the recent experimental announcements for direct measurements of time-reversal non-invariance in the neutral kaon system, we make a comparative discussion of the CPLEAR and KTeV measurements. The most suitable way to consistently incorporate the mixing, the time evolution and the decays of kaons, is to describe the neutral kaon system as a syste

F. J. Yndurain

Sum rules for the nonperturbative piece of correlators (specifically, the vector current correlator) are discussed. The sum rule subtracting the perturbative part is of the superconvergent type. Thus it is dominated by the bound states and low energy production cross section. It leads to a determination of the gluon condensate of $<α_s G^2> = 0.048 \pm 0.039

Robert Fleischer

The decays $B_d\to π^+ π^-$ and $B_s\to K^+ K^-$ are related to each other by interchanging all down and strange quarks, i.e. through the $U$-spin flavour symmetry of strong interactions. A completely general parametrization of the CP-violating observables of these modes is presented within the framework of the Standard Model, allowing the determination of t

Robert Fleischer

A completely general parametrization of the time-dependent decay rates of the modes $B_s\to J/ψK_S$ and $B_d\to J/ψK_S$ is given, which are related to each other through the $U$-spin flavour symmetry of strong interactions. Owing to the interference of current--current and penguin processes, the $B_s\to J/ψK_S$ observables probe the angle $γ$ of the unitarit

S. M. Bilenky, C. Giunti, W. Grimus, T. Schwetz

In the framework of schemes with mixing of four massive neutrinos, which can accommodate the atmospheric, solar and LSND ranges of Delta m^2, we show that, in the whole region of Delta m^2_{LSND} allowed by LSND, the Super-Kamiokande up-down asymmetry excludes all mass spectra with a group of three close neutrino masses separated from the fourth mass by the

Ratindranath Akhoury, Michael G. Sotiropoulos, George Sterman

A leading twist expansion in terms of bilocal operators is proposed for the structure functions of deeply inelastic scattering near the elastic limit $x \to 1$, which is also applicable to a range of other hard quasi-elastic processes. Operators of increasing dimensions contribute to logarithmically enhanced terms, which are suppressed by corresponding power

Ph. de Forcrand

This review describes the multiboson algorithm for Monte Carlo simulations of lattice QCD, including its static and dynamical aspects, and presents a comparison with Hybrid Monte Carlo.

S. H. Kettell

The first observation of the decay $K^+ \to π^+ ν\barν$ (pnn) has been reported. The E787 experiment presented evidence for this decay, based on the observation of a single clean event from data collected during the 1995 run of the AGS (Alternating Gradient Synchrotron at Brookhaven National Laboratory). The branching ratio indicated by this observation, B(p

S. Q. Wu, X. Cai

The classical first law of thermodynamic for Kerr-Newmann black hole (KNBH) is generalized to that in quantum form on event horizon. Then four quantum conservation laws on the KNBH equilibrium radiation process are derived, and Bekenstein-Hawking&#39;s relation S=A/4 is recovered. It can be argued that the classical entropy of black hole arise from the quant

Rob Kling, Geoffrey McKim

Electronic publishing opportunities, manifested today in a variety of electronic journals and Web-based compendia, have captured the imagination of many scholars. These opportunities have also destabilized norms about the character of legitimate scholarly publishing in some fields. Unfortunately, much of the literature about scholarly e-publishing homogenize

C. Tsallis

The domain of validity of standard thermodynamics and Boltzmann-Gibbs statistical mechanics is discussed and then formally enlarged in order to hopefully cover a variety of anomalous systems. The generalization concerns {\it nonextensive} systems, where nonextensivity is understood in the thermodynamical sense. This generalization was first proposed in 1988

V. R. Galakhov, S. Uhlenbrock, S. Bartkowski, A. V. Postnikov

We present metal 3s x-ray photoelectron spectra of different transition metal oxides. The values of the 3s exchange splitting for the 3d metal oxides are given as a function of the 3d electron number in the ground state. The spectra were analysed using the simple two-configuration model of the interatomic configuration mixing. The change of the 3s spectra is

M. Grueninger, D. van der Marel, A. A. Tsvetkov, A. Erb

The temperature dependence of the c-axis optical conductivity σ(ω) of optimally and overdoped YBa_2Cu_3O_x (x=6.93 and 7) is reported in the far- (FIR) and mid-infrared (MIR) range. Below T_c we observe a transfer of spectral weight from the FIR not only to the condensate at ω= 0, but also to a new peak in the MIR. This peak is naturally explained as a trans

E. Lipparini, M. Barranco, A. Emperador, M. Pi

We have carried out a systematic analysis of the transverse dipole spin response of a large size quantum dot within time-dependent current density functional theory. Results for magnetic fields corresponding to integer filling factors are reported, as well as a comparison with the longitudinal dipole spin response. As in the two dimensional electron gas, the

Yuriy E. Kuzovlev

The 1/f-noise is considered which has no relation to long-lasting processes but originates from the same dynamical mechanisms as what are responsible for the loss of memory, fast relaxation and usual shot noise. The universal long-range statistics of memoryless random flows of events and of related Brownian motion is analysed whose peculiarity is close conne

T. Inoue, M. Nishida, S. Kurihara

The resistivity of a one-dimensional Josephson junction array at zero temperature is calculated by estimating the nucleation rate of quantum phase slips. We choose a certain collective coordinate which describes the nucleation process and estimate the corresponding effective mass. In the strong coupling regime, where Josephson coupling energy exceeds the cha

Biplab Sanyal, Abhijit Mookerjee

We here study magnetic properties of Ni$_{x}$Fe$_{1-x}$ using Augmented space recursion technique coupled with tight-binding linearized muffin tin orbital method. Also the spectral properties of this alloy has been studied here.

Remi Monasson

The spectral properties of the Laplacian operator on ``small-world&#39;&#39; lattices, that is mixtures of unidimensional chains and random graphs structures are investigated numerically and analytically. A transfer matrix formalism including a self-consistent potential a la Edwards is introduced. In the extended region of the spectrum, an effective medium c

E. V. Bezuglyi, E. N. Bratus&#39;, V. P. Galaiko

Specific features of the equilibrium current-carrying state of a Josephson tunnel junction between diffusive superconductors are studied theoretically in the 1D geometry. It is found that the Josephson current induces localized states of electron excitations in the vicinity of the tunnel barrier, which are a continuous analog of Andreev levels in a ballistic

Hideo Yoshioka

Transport properties of disordered carbon nanotubes are investigated with including long range Coulomb interactions. The resistivity and optical conductivity are calculated by using the memory functional method. In addition, the effect of localization is taken into account by use of the renormalization group analysis and it is shown that the backward scatter

Staffan Grundberg, Jørgen Rammer

The dynamic melting of vortex lattices in type II superconductors is considered. A field-theoretic formulation of the pinning problem allows the average over the quenched disorder to be performed exactly. A self-consistent theory is constructed using a functional method for the effective action, allowing a determination of the pinning force and the vortex fl

M. E. Spina, M. Saraceno

We study the classical motion in bidimensional polygonal billiards on the sphere. In particular we investigate the dynamics in tiling and generic rational and irrational equilateral triangles. Unlike the plane or the negative curvature cases we obtain a complex but regular dynamics.

D. U. Matrasulov

Chaotization of supercritical (Z>137) hydrogenlike atom in the monochromatic field is investigated. A theoretical analysis of chaotic dynamics of the relativistic electron based on Chirikov criterion is given. Critical value of the external field at which chaotization will occur is evaluated analytically. The diffusion coefficient is also calculated.

Daniela Pierotti, Victor S. L&#39;vov, Anna Pomyalov, Itamar Procaccia

The major difficulty in developing theories for anomalous scaling in hydrodynamic turbulence is the lack of a small parameter. In this Letter we introduce a shell model of turbulence that exhibits anomalous scaling with a tunable small parameter. The small parameter $ε$ represents the ratio between deterministic and random components in the coupling between

Vassilios M. Rothos, Tassos C. Bountis

It has been proved by S.L.Ziglin, for a large class of 2-degree-of-freedom (d.o.f) Hamiltonian systems, that transverse intersections of the invariant manifolds of saddle fixed points imply infinite branching of solutions in the complex time plane and the non-existence of a second analytic integral of the motion. Here, we review in detail our recent results,

G. Neugebauer, K. Matthews

Twenty five low redshift quasars have been monitored for several decades at five near- and mid-infrared wavelengths to detect rapid variations which would indicate that a nonthermal component was present in the &#34;10 micron bump&#34;. Such variability has apparently been detected in several radio loud quasars and in the radio quiet quasar PG1535+547. In ad

Tanmay Vachaspati

In these lectures, I describe the formation of defect distributions in first-order phase transitions, then briefly discuss the relevance of defect interactions after a phase transition and the observational signatures of cosmic strings. Some open questions are also discussed.

John A. Tomsick, Jules P. Halpern, Jonathan Kemp, Philip Kaaret

We report on optical and RXTE observations of a new high-latitude bursting X-ray transient, XTE J2123-058. We identified the optical counterpart, measured the 5.9573 hr orbital period and constrained the binary inclination and the source distance. The distance lower limit indicates that the source is at least 2.6 kpc from the Galactic plane, which is unusual

N. Ryde, F. L. Schoeier, H. Olofsson

We have modelled radio and far-infrared rotational lines of 12^CO and 13^CO obtained from the circumstellar envelope of the infrared-bright carbon star IRAS 15194-5115. Eleven rotational lines between J=1-0 and 21-20 and nine rotational lines between J=1-0 and 22-21 in the ground vibrational states of 12^CO and 13^CO, respectively, provide the observational

Etienne Parizot, Luke Drury

We calculate the spallative production of light elements associated with the explosion of an isolated supernova in the interstellar medium, using a time-dependent model taking into account the dilution of the ejected enriched material and the adiabatic energy losses. We first derive the injection function of energetic particles (EPs) accelerated at both the

B. Novosyadlyj

The possibility of determining MDM model parameters on the basis of observable data on the Abell-ACO power spectrum and mass function is analysed. It is shown that spectrum area corresponding to these data is sensitive enough to such MDM model parameters as neutrino mass $m_ν$, number species of massive neutrino $N_ν$, baryon content $Ω_b$ and Hubble constan

Etienne Parizot

We present a general model allowing one to calculate the distribution function of energetic particles in the interstellar medium, and hence any relevant nuclear reaction rate, for any given time-dependent injection function, as well as in situations when the propagation coefficients themselves are non stationary. We review and provide physical interpretation

A. L. Zezas, I. Georgantopoulos, M. J. Ward

We present ROSAT PSPC and HRI observations of the dwarf irregular galaxy Holmberg II (UGC4305). This is one of the most luminous dwarf galaxies (Lx~ 10^{40} erg s^{-1} cm^{-2}) detected in the ROSAT All-Sky Survey. The X-ray emission comes from a single unresolved point source, coincident with a large HII region which emits intense radio emission. The source

M. Jaroszynski

We simulate the observations of proper motion of stars very close to the Galactic Center. We show that the speckle interferometry done with the Keck II telescope is accurate enough to obtain orbital parameters for stars with the period P about 10 y during 10 seasons of astrometric observations made once a year. The determination of a single orbit will give c

Yashwant Gupta, N. D. Ramesh Bhat, A. Pramesh Rao

Refraction of pulsar radiation by electron density irregularities in the interstellar medium sometimes produces multiple imaging of pulsars which can lead to periodic oscillations of intensity in pulsar dynamic spectra records. Such events can be used as tools to resolve the emission regions in pulsar magnetospheres. Here we describe results from the recent

M. A. Aloy, J. M. Ibanez, J. M. Marti, E. Muller

The main features of a three dimensional, high-resolution special relativistic hydro code based on relativistic Riemann solvers are described. The capabilities and performance of the code are discussed. In particular, we present the results of extensive test calculations which demonstrate that the code can accurately and efficiently handle strong shocks in t

F. M. Walter, J. M. Alcala, R. Neuhaeuser, M. Sterzik

The OB associations, which are fossil star formation regions, retain the end-products of the star formation process in an open, unobscured environment. Observations of the low mass stars in OB associations provide a far clearer picture of the results of the star formation process than do observations of embedded, on-going star formation regions. We review th

L. Silva, G. L. Granato, A. Bressan, C. G. Lacey

We present the basic features and preliminary results of the interface between our spectro-photometric model GRASIL (that calculates galactic SED from the UV to the sub-mm with a detailed computation of dust extinction and thermal reemission) with the semi-analytical galaxy formation model GALFORM (that computes galaxy formation and evolution in the hierarch

G. L. Granato, L. Silva, L. Danese, G. Rodighiero

We summarize our modelling of galaxy photometric evolution (GRASIL code). By including the effects of dust grains and PAHs molecules in a two phases clumpy medium, where clumps are associated to star forming regions, we reproduce the observed UV to radio SEDs of galaxies with star formation rates from zero to several hundreds $M_\odot/yr$. GRASIL is a powerf

T. Bremnes, B. Binggeli, P. Prugniel

We have carried out CCD photometry in the Cousins B and R bands of 21 dwarf galaxies in and around the M101 group. Eleven are members and suspected members of the group and ten are field galaxies in the projected vicinity of the group. We have derived total magnitudes, effective radii, effective surface brightnesses, as well as galaxy diameters at various is

R. I. Bagduev

A deep underwater Cherenkov telescope has been operating since 1993 in stages of growing size at 1.1 km depth in Lake Baikal. The key component of the telescope is the Optical Module (OM) which houses the highly sensitive phototube QUASAR-370. We describe design and parameters of the QUASAR-370, the layout of the optical module, the front-end electronics and

P. M. Chadwick, K. Lyons, T. J. L. McComb, K. J. Orford

Observations have been made, using the University of Durham Mark 6 gamma ray telescope, of the very high energy gamma ray emission from a number of active galactic nuclei visible from the Southern hemisphere. Limits are presented to the VHE gamma ray emission from 1ES 0323+022, PKS 0829+046, 1ES 1101--232, Cen A, PKS 1514-24, RXJ 10578-275, and 1ES 2316-423,

R. A. Knox, M. R. S. Hawkins, N. C Hambly

We describe a new multi-colour proper motion survey for cool white dwarfs (CWDs). The observational database consists of ~300 digitally scanned Schmidt plates in ESO/SERC field 287. The entire survey procedure, from the raw Schmidt plate data to final white dwarf luminosity function (WDLF) is described, with special emphasis on completeness concerns. We obta

Catarina Lobo, Bruno Guiderdoni

In spite of their overall success, semi-analytic models of galaxy formation and evolution predict slopes of luminosity functions which are steeper than the observed ones. This discrepancy has generally been explained by subtle surface brightness effects acting on the observational samples. In this paper, we explicitly implement the computation of surface bri

Baikal Collaboration, V. A. Balkanov et al

We present results of an experiment performed in Lake Baikal at a depth of about 1 km. The photomultipliers of an underwater neutrino telescope under construction at this site have been illuminated by a distant laser. The experiment not only provided a useful cross-check of the time calibration of the detector, but also allowed to determine inherent optical

Baikal Collaboration, V. A. Balkanov et al

We present first neutrino induced events observed with a deep underwater neutrino telescope. Data from 70 days effective life time of the BAIKAL prototype telescope NT-96 have been analyzed with two different methods. With the standard track reconstruction method, 9 clear upward muon candidates have been identified, in good agreement with 8.7 events expected

D. T. Frayer, R. J. Ivison, I. Smail, M. S. Yun

We report on 450- and 850-micron observations of the interacting galaxy pair, VV114E+W (IC1623), taken with the SCUBA camera on the James Clerk Maxwell Telescope, and near-infrared observations taken with UFTI on the UK Infrared Telescope. The system VV114 is in an early stage of a gas-rich merger. We detect submillimeter (sub-mm) emission extended over 30 a

Re&#39;em Sari, Tsvi Piran, Jules Halpern

In several GRBs afterglows, rapid temporal decay is observed which is inconsistent with spherical (isotropic) blast-wave models. In particular, GRB 980519 had the most rapidly fading of the well-documented GRB afterglows, with t^{-2.05\pm 0.04} in optical as well as in X-rays. We show that such temporal decay is more consistent with the evolution of a jet af

G. R. Knapp, K. Young, M. Crosas

CO(J = 2-1) and SiO(J = 5-4) emission has been observed from the molecular envelope around the nearby S star pi Gru. The CO line profile differs from the usual parabolic shape seen in uniformly expanding envelopes; it has a Voigt-like profile and two horns. A model for line formation in the envelope shows that a tilted, expanding disk reproduces the observat

A. A. Ivanov, V. P. Egorova, V. A. Kolosov, A. D. Krasilnikov

The Earth&#39;s magnetic field effect on the azimuthal distribution of extensive air showers (EAS) of cosmic rays has been evaluated using a bulk of the Yakutsk array data. The uniform azimuthal distribution of the EAS event rate is rejected at the significance level 10^(-14). Amplitude of the first harmonics of observed distribution depends on zenith angle

Zoltan Haiman, Tom Abel, Martin J. Rees

In hierarchical models of structure formation, an early cosmic UV background (UVB) is produced by the small (T_vir < 10^4 K) halos that collapse before reionization. The UVB at energies below 13.6eV suppresses the formation of stars or black holes inside small halos, by photo-dissociating their only cooling agent, molecular H2. We self-consistently compute t

Rupert A. C. Croft, Wayne Hu, Romeel Dave&#39;

The Lya forest in quasar spectra probes scales where massive neutrinos can strongly suppress the growth of mass fluctuations. Using hydrodynamic simulations with massive neutrinos, we successfully test techniques developed to measure the mass power spectrum from the forest. A recent observational measurement in conjunction with a conservative implementation

J. Giannakopoulou-Creighton, M. Fich, C. D. Wilson

The molecular components of three giant HII regions (NGC 5461, NGC 5462, NGC 5471) in the galaxy M101 are investigated with new observations from the James Clerk Maxwell Telescope, the NRAO 12-meter, and the Owens Valley millimeter array. Of the three HII regions, only NGC 5461 had previously been detected in CO emission. We calculate preliminary values for

D. S. Salopek

As the quality of cosmological data continue to improve, it is natural to test the statistics of primordial fluctuations: are they Gaussian or non-Gaussian? I review a model which generates non-Gaussian adiabatic fluctuations from inflation. Current investigations suggest that there may possibly be a non-Gaussian signal in large angle cosmic microwave backgr

Cathie J. Clarke, Ian A. Bonnell, Lynne A. Hillenbrand

We review recent work that investigates the formation of stellar clusters, ranging in scale from globular clusters through open clusters to the small scale aggregates of stars observed in T associations. In all cases, recent advances in understanding have been achieved through the use of state of the art stellar dynamical and gas dynamical calculations, comb

M. Berkooz, A. Kapustin

We review some of the problems associated with deriving field theoretic results from nonsupersymmetric AdS, focusing on how to control the behavior of the field theory along the flat directions. We discuss an example in which the origin of the moduli space remains a stable vacuum at finite $N$, and argue that it corresponds to an interacting CFT in three dim

K. Hatano, D. Branch, A. Fisher, E. Baron

Synthetic spectra generated with the parameterized supernova synthetic-spectrum code SYNOW are compared to spectra of the Type Ia SN 1994D that were obtained before the time of maximum brightness. Evidence is found for the presence of two-component Fe II and Ca II features, forming in high velocity ($\ge 20,000$ \kms) and lower velocity ($\le 16,000$ \kms) m

W. Mueck, K. S. Viswanathan

We consider the non-interacting massive Wess-Zumino model in four-dimensional anti-de Sitter space and show that the conformal dimensions of the corresponding boundary fields satisfy the relations expected from superconformal invariance. In some cases the irregular mode must be used for one of the scalar fields.

Joanne M. Attridge, David H. Roberts, John F. C. Wardle

As part of our study of the magnetic fields of AGN we have recently observed a large sample of blazars with the Very Long Baseline Array. Here we report the discovery of a striking two-component jet in the source 1055+018, consisting of an inner spine with a transverse magnetic field, and a fragmentary but distinct boundary layer with a longitudinal magnetic

James B. Dove, J. Michael Shull, Andrea Ferrara

By solving the time-dependent radiation transfer problem of stellar radiation through evolving superbubbles within a smoothly varying HI distribution, we estimate the fraction of ionizing photons emitted by OB associations that escapes the HI disk of our Galaxy into the halo and intergalactic medium (IGM). We consider both coeval star-formation and a Gaussia

C. S. Froning, E. L. Robinson, William F. Welsh, Janet H. Wood

We present near-infrared, H-band (1.45-1.85 microns) observations of the eclipsing dwarf nova, IP Peg, in quiescence. The light curves are composed of ellipsoidal variations from the late-type secondary star and emission from the accretion disk and the bright spot. The light curves have two eclipses: a primary eclipse of the accretion disk and the bright spo

A. E. Dorokhov, S. V. Esaibegyan, A. E. Maximov, S. V. Mikhailov

We suggest a constrained instanton (CI) solution in the physical QCD vacuum which is described by large-scale vacuum field fluctuations. This solution decays exponentially at large distances. It is stable only if the interaction of the instanton with the background vacuum field is small and additional constraints are introduced. The CI solution is explicitly

Laurent Freidel, Kirill Krasnov

We show how spin networks can be described and evaluated as Feynman integrals over an internal space. This description can, in particular, be applied to the so-called simple SO(D) spin networks that are of importance for higher-dimensional generalizations of loop quantum gravity. As an illustration of the power of the new formalism, we use it to obtain the a

J. Kwiecinski, A. D. Martin, J. J. Outhwaite

We compare predictions based on small x (QCD) dynamics with recent data for deep inelastic events containing forward jets or forward pi0 mesons. We quantify the effect of imposing the (higher order) consistency condition on the BFKL equation and study uncertainties inherent in the QCD predictions. We also estimate the cross-section for the forward production

J. N. Prata

We compute the boundary entropies for the allowed boundary conditions of the SU(2)-invariant principal chiral model at level k=1. We used the reflection factors determined in a previous work. As a by-product we obtain some miscellaneous results such as the ground-state energy for mixed boundary conditions as well as the degeneracies of the Kondo model in the

Gerard &#39;t Hooft

It is argued that the so-called holographic principle will obstruct attempts to produce physically realistic models for the unification of general relativity with quantum mechanics, unless determinism in the latter is restored. The notion of time in GR is so different from the usual one in elementary particle physics that we believe that certain versions of

M. A. Martin-Delgado, G. Sierra

We apply the DMRG method to the 2 dimensional delta function potential which is a simple quantum mechanical model with asymptotic freedom and formation of bound states. The system block and the environment block of the DMRG contain the low energy and high energy degrees of freedom, respectively. The ground state energy and the lowest excited states are obtai

M. A. Ivanov, P. Santorelli

We employ the relativistic constituent quark model to give a unified description of the leptonic and semileptonic decays of pseudoscalar mesons (π, K, D, D_s, B, B_s). The calculated leptonic decay constants and form factors are found to be in good agreement with available experimental data and other approaches. We reproduce the results of spin-flavor symmet

Maximo Banados

Twisted sectors --solutions to the equations of motion with non-trivial monodromies-- of three dimensional Euclidean gravity are studied. We argue that upon quantization this new sector of the theory provides the necessary (and no more) degrees of freedom to account for the Bekenstein-Hawking entropy.

T. Krajewski, R. Wulkenhaar

Using standard field theoretical techniques, we survey pure Yang-Mills theory on the noncommutative torus, including Feynman rules and BRS symmetry. Although in general free of any infrared singularity, the theory is ultraviolet divergent. Because of an invariant regularization scheme, this theory turns out to be renormalizable and the detailed computation o