November 2000 arXiv papers — page 2

Kristy K. Dyer, Stephen P. Reynolds, Kazik J. Borkowski, Robert Petre

The 10^51 ergs released in a supernova have far reaching consequences in the galaxy, determining elemental abundances, accelerating cosmic rays, and affecting the makeup of the interstellar medium. Recently the spectra of several supernova remnants have been found to be dominated by nonthermal emission. Separating the thermal and nonthermal components is imp

Michael R. Merrifield

These lectures are intended to provide an introduction to the rich interplay between N-body simulations and stellar-kinematic observations of galaxies. The first section describes the kinematic properties of galaxies that are accessible to observation, and gives a brief introduction to the stellar dynamics that one might wish to infer from such observations.

K. A. Misselt, K. D. Gordon, G. C. Clayton, M. J. Wolff

In this paper and a companion paper we present the DIRTY model, a Monte Carlo radiative transfer code, self-consistently including dust heating and emission, and accounting for the effects of the transient heating of small grains. The code is completely general; the density structure of the dust, the number and type of heating sources, and their geometric co

Karl D. Gordon, K. A. Misselt, Adolf N. Witt, Geoffrey C. Clayton

We present the DIRTY radiative transfer model in this paper and a companion paper. This model computes the polarized radiative transfer of photons from arbitrary distributions of stars through arbitrary distributions of dust using Monte Carlo techniques. The dust re-emission is done self-consistently with the dust absorption and scattering and includes all t

M. Audard, M. Guedel, A. J. den Boggende, A. C. Brinkman

First results from high-resolution coronal spectroscopy of flares with the Reflection Grating Spectrometers on board the \textit{XMM-Newton} satellite are reviewed. Rotational modulation in the X-ray light curve of HR 1099 is discussed. Results from time-dependent spectroscopy of flares in the active stars HR 1099, AB Dor, YY Gem are also presented. Variatio

M. Guedel, M. Audard, A. J. den Boggende, A. C. Brinkman

First results from high-resolution coronal spectroscopy with the {\it XMM-Newton} Reflection Grating Spectrometers (RGS) are reviewed. Five stellar systems (HR 1099, Capella, Procyon, YY Gem, AB Dor) have been observed. The emphasis of the present paper is on overall coronal structure. Elemental abundances in {\it active stars} are found to be `anomalous&#39

M. Guedel, M. Audard, E. F. Guinan, J. J. Drake

In spring 1999, a long coordinated observing campaign was performed on the flare star AD Leo, including {\it EUVE}, {\it BeppoSAX}, the {\it VLA}, and optical telescopes. The campaign covered a total of 44 days. We obtained high-quality light curves displaying ongoing variability on various timescales, raising interesting questions on the role of flare-like

Scott Tremaine

Low-mass disks orbiting a massive body can support "slow" normal modes, in which the eigenfrequency is much less than the orbital frequency. Slow modes are lopsided, i.e., the azimuthal wavenumber m=1. We investigate the properties of slow modes, using softened self-gravity as a simple model for collective effects in the disk. We employ both the WKB

Pedro Augusto, Peter N. Wilkinson

A radio-based search for strong gravitational lensing, with image separations in the range 160-300 milliarcsec (mas), has yielded a null result for a sample of 1665 sources (Augusto, Wilkinson & Browne 1998) whose mean redshift is estimated to be ~1.3. The lensing rate for this previously-unexplored separation range, <1:555 at the 95% confidence level, is le

Walter Dehnen

In N-body simulations of collisionless stellar systems, the forces are softened to reduce the shot noise. Softening modifies gravity at r=|x-y| smaller than softening length epsilon and the softened forces are increasingly biased for ever larger epsilon. There is, thus, some optimum between reducing the fluctuations and introducing a bias. Here, analytical r

Brad K. Gibson, Chris B. Brook

The methodology involved in deriving the Hubble Constant via the calibration of the corrected peak luminosities of Type Ia supernovae (SNe) is reviewed. We first present a re-analysis of the Calan-Tololo (C-T) and Center for Astrophysics (CfA) Type Ia SN surveys. Bivariate linear least squares and quadratic boot-strapped fits in peak apparent magnitude and l

A. C. Fabian, A. Celotti, K. Iwasawa, R. G. McMahon

We report optical, radio and X-ray observations of a new distant blazar, PMN J0525-3343, at a redshift of 4.4. The X-ray spectrum measured from ASCA and BeppoSAX flattens below a few keV, in a manner similar to the spectra of two other z>4 blazars, GB 1428+4217 (z=4.72) reported by Boller et al and RXJ 1028.6-0844 (z=4.28) by Yuan et al. The spectrum is well

Jos H. J. de Bruijne, Ronnie Hoogerwerf, P. Tim de Zeeuw

Hipparcos parallaxes fix distances to individual stars in the Hyades cluster with an accuracy of 6%. We use the Hipparcos (and Tycho-2) proper motions, which have a larger relative precision than the trigonometric parallaxes, to derive ~3 times more precise distance estimates, by assuming that all members share the same space motion. The improved parallaxes

F. De Paolis, G. Ingrosso, A. A. Nucita

Astrophysical implications of gravitational microlensing of gravitational waves emitted by rotating neutron stars (NSs) are investigated. In particular, attention is focused on the following situations: i) NSs in the galactic bulge lensed by a central black hole of $2.6\times 10^6 M_{\odot}$ or by stars and MACHOs distributed in the galactic bulge, disk and

H. Schild, T. Dumm, U. Muerset, H. Nussbaumer

We present new dynamical parameters of the AR Pav binary system. Ourobservations consist of a series of high resolution optical/NIR spectra from which we derive the radial velocity curve of the red giant as well as its rotation velocity. Assuming co-rotation, we determine the stellar radius (130 R_solar) of the red giant. Based on this we derive the red gian

F. Hulleman, M. H. van Kerkwijk, S. R. Kulkarni

The energy source of the anomalous X-ray pulsars is not well understood, hence their designation as anomalous. Unlike binary X-ray pulsars, no companions are seen, so the energy cannot be supplied by accretion of matter from a companion star. The loss of rotational energy, which powers radio pulsars, is insufficient to power AXPs. Two models are generally co

Kaspar von Braun, Mario Mateo

Differential $E_{V-I}$ variations of up to $\sim 0.2$ mag on a scale of arcminutes across NGC 3201 are presented in the form of an extinction map. This map, created by calculating average $E_{V-I}$ values for stars in small subregions of the field with respect to a fiducial region, greatly improves the appearance of the CMD of the cluster. We describe how we

Matias Zaldarriaga, Lam Hui, Max Tegmark

We use published measurements of the transmission power spectrum of the Lyman alpha forest to constrain several parameters that describe cosmology and thermal properties of the intergalactic medium (IGM). A 6 parameter grid is constructed using Particle-Mesh dark matter simulations together with scaling relations to make predictions for the gas properties. W

Hsiao-Wen Chen, Kenneth M. Lanzetta, Sebastian Pascarelle, Noriaki Yahata

Observations of distant galaxies are important both for understanding how galaxies form and for probing the physical conditions of the universe at the earliest epochs. It is, however, extremely difficult to identify galaxies at redshift z>5, because these galaxies are faint and exhibit few spectral features. In a previous work, we presented observations that

R. Nichol, C. Miller, A. Connolly, S. Chong

We outline here the next generation of cluster-finding algorithms. We show how advances in Computer Science and Statistics have helped develop robust, fast algorithms for finding clusters of galaxies in large multi-dimensional astronomical databases like the Sloan Digital Sky Survey (SDSS). Specifically, this paper presents four new advances: (1) A new semi-

B. Fuchs

The `maximum&#39; disk hypothesis of galactic disks imbedded in dark matter halos is examined. First, decompositions of the rotation curves of NGC 2613, 3198, 6503, and 7184 are analyzed. For these galaxies the radial velocity dispersions of the stars have been measured. If the parameters of the decompositions are chosen according to the `maximum&#39; disk h

J. Garriga, A. Vilenkin

We critically review several recent approaches to solving the two cosmological constant problems. The &#34;old&#34; problem is the discrepancy between the observed value of $Λ$ and the large values suggested by particle physics models. The second problem is the &#34;time coincidence&#34; between the epoch of galaxy formation $t_G$ and the epoch of $Λ$-domina

Charis Anastopoulos

We study the transition from the full quantum mechanical description of physical systems to an approximate classical stochastic one. Our main tool is the identification of the closed-time-path (CTP) generating functional of Schwinger and Keldysh with the decoherence functional of the consistent histories approach. Given a degree of coarse-graining in which i

Joseph A. Collins, Richard J. Rand

Deep long-slit spectra of the diffuse ionized gas halos of the edge-on spiral galaxies NGC 4302 and UGC 10288 are presented. These data, along with previously presented data for NGC 5775 and NGC 891, are used to address the issue of how DIG halos are energized. Composite photo-ionization/shock models are generally better at explaining runs of line ratios in

Joseph A. Both, Daniel C. Hong, Douglas A. Kurtze

We present a one dimensional model for the development of corrugations in roads subjected to compressive forces from a flux of cars. The cars are modeled as damped harmonic oscillators translating with constant horizontal velocity across the surface, and the road surface is subject to diffusive relaxation. We derive dimensionless coupled equations of motion

Piotr T. Chrusciel, Gabriel Nagy

We give a definition of mass for spacelike hypersurfaces in space-times with metrics which are asymptotic to the anti-de Sitter one, or to a class of generalizations thereof. We present the results of gr-qc/0110014 which show that our definition provides a geometric invariant for a spacelike hypersurface embedded in a space-time. Some further global invarian

A. Katsikatsou, A. B. Lahanas, D. V Nanopoulos, V. C. Spanos

We reexamine the one-loop corrections to the mass of the pseudo-scalar Higgs boson, using the effective potential. In the absence of the chargino and neutralino contributions its mass exhibits a large scale dependence in the large $M_{1/2}$ regime, especially for values of $\tan β>20$. Thus, although of electroweak origin, the heaviness of the $M_{1/2}$, in

P. A. Grassi, P. van Nieuwenhuizen

Adding explicit mass terms for the spin 2 and spin 3/2 field of N=1 anti-de Sitter supergravity, the limit M --> 0 for these mass terms is smooth: there is no van Dam-Veltman-Zakharov mass discontinuity in the propagators when the cosmological constant is non-vanishing.

J. J. van der Bij, K. G. Chetyrkin, M. Faisst, G. Jikia

We present analytical results for the leading contributions of the top quark to the electroweak rho parameter at order GF^3 Mt^6 and GF^2 Mt^4 alpha_s. The Higgs boson and the gauge bosons are taken to be massless in this limit. The correction of order GF^3 Mt^6 is found to be sizeable in comparison to the the leading two-loop GF^2 Mt^4 correction, however i

Anindya Datta, Raj Gandhi, Biswarup Mukhopadhyaya, Poonam Mehta

Neutrino oscillation signals at muon storage rings can be faked by supersymmetric (SUSY) interactions in an R-parity violating scenario. We investigate the $τ$-appearance signals for both long-baseline and near-site experiments, and conclude that the latter is of great use in distinguishing between oscillation and SUSY effects. On the other hand, SUSY can ca

Jonathan L. Feng, Konstantin T. Matchev

In focus point supersymmetry, all squarks and sleptons, including those of the third generation, have multi-TeV masses without sacrificing naturalness. We examine the implications of this framework for low energy constraints and the light Higgs boson mass. Undesirable contributions to proton decay and electric dipole moments, generic in many supersymmetric m

E. Oset, D. Jido, J. E. Palomar

We take an approach to the $Λ$ nonmesonic weak decay in nuclei based on the exchange of mesons under the guidelines of chiral Lagrangians. The one pion and one kaon exchange are considered, together with the exchange of two pions, either correlated, leading to an important scalar-isoscalar exchange ($σ$-like exchange), or uncorrelated (box diagrams). A drast

J. Ambjorn, J. Jurkiewicz, R. Loll

We have recently introduced a discrete model of Lorentzian quantum gravity, given as a regularized non-perturbative state sum over simplicial Lorentzian space-times, each possessing a unique Wick rotation to Euclidean signature. We investigate here the phase structure of the Wick-rotated path integral in three dimensions with the aid of computer simulations.

Prem P. Srivastava, Stanley J. Brodsky

The light-front (LF) quantization of QCD in light-cone gauge has a number of remarkable advantages, including explicit unitarity, a physical Fock expansion, the absence of ghost degrees of freedom, and the decoupling properties needed to prove factorization theorems in high momentum transfer inclusive and exclusive reactions. We present a systematic study of

Eric D. Chisolm

The proof of the Heisenberg uncertainty relation is modified to produce two improvements: (a) the resulting inequality is stronger because it includes the covariance between the two observables, and (b) the proof lifts certain restrictions on the state to which the relation is applied, increasing its generality. The restrictions necessary for the standard in

Eric D. Chisolm, Brad E. Clements, Duane C. Wallace

We present a model for the motion of an average atom in a liquid or supercooled liquid state and apply it to calculations of the velocity autocorrelation function $Z(t)$ and diffusion coefficient $D$. The model trajectory consists of oscillations at a distribution of frequencies characteristic of the normal modes of a single potential valley, interspersed wi

Pieter Kok, Samuel L Braunstein

We study a class of optical circuits with vacuum input states consisting of Gaussian sources without coherent displacements such as down-converters and squeezers, together with detectors and passive interferometry (beam-splitters, polarisation rotations, phase-shifters etc.). We show that the outgoing state leaving the optical circuit can be expressed in ter

Jürgen König, Martin Chr. Bønsager, Allan H. MacDonald

Metallic thin film ferromagnets generically possess spiral states that carry dissipationless spin currents. We relate the critical values of these supercurrents to micromagnetic material parameters, identify the circumstances under which the supercurrents will be most robust, and propose experiments which could reveal this new collective transport behavior.

G. Corcella, I. G. Knowles, G. Marchesini, S. Moretti

HERWIG is a general-purpose Monte Carlo event generator, which includes the simulation of hard lepton-lepton, lepton-hadron and hadron-hadron scattering and soft hadron-hadron collisions in one package. It uses the parton-shower approach for initial- and final-state QCD radiation, including colour coherence effects and azimuthal correlations both within and

Ya. M. Blanter, A. D. Mirlin, B. A. Muzykantskii

Statistical properties of billiards with diffusive boundary scattering are investigated by means of the supersymmetric sigma-model in a formulation appropriate for chaotic ballistic systems. We study level statistics, parametric level statistics, and properties of electron wavefunctions. In the universal regime, our results reproduce conclusions of the rando

Daniel Rohe, Walter Metzner

One-particle spectral properties in the normal phase of the two-dimensional attractive Hubbard model are investigated in the weak coupling regime using the non-selfconsistent T-matrix approximation. The corresponding equations are evaluated numerically directly on the real frequency axis. For temperatures sufficiently close to the superconducting transition

J. S. Sa&#39; Martins, Adriana Racco

Motivated by the cyclic pattern of reproductive regimes observed in some species of green flies (``{\it aphids}&#39;&#39;), we simulate the evolution of a population enduring harsh seasonal conditions for survival. The reproductive regime of each female is also seasonal in principle and genetically acquired, and can mutate for each newborn with some small pr

A. Bardou, B. v. Rekowski, W. Dobler, A. Brandenburg

We consider the effect of vertical outflows on the mean-field dynamo in a thin disk. These outflows could be due to winds or magnetic buoyancy. We analyse both two-dimensional finite-difference numerical solutions of the axisymmetric dynamo equations and a free-decay mode expansion using the thin-disk approximation. Contrary to expectations, a vertical veloc

Marcus Gaul, Carlo Rovelli

We study a generalized version of the Hamiltonian constraint operator in nonperturbative loop quantum gravity. The generalization is based on admitting arbitrary irreducible SU(2) representations in the regularization of the operator, in contrast to the original definition where only the fundamental representation is taken. This leads to a quantization ambig

E. Orignac, T. Giamarchi

We investigate the effect of a magnetic field on a bosonic ladder. We show that such a system leads to the one dimensional equivalent of a vortex lattice in a superconductor. We investigate the physical properties of the vortex phase, such as vortex density and vortex correlation functions and show that magnetization has plateaus for some commensurate values

Ralph Blumenhagen, Anamaria Font

We analyze the backreaction of dilaton tadpoles on the geometry of non-supersymmetric strings. After finding explicit warped solutions for a T-dual version of the Sugimoto model, we examine the possibility of realizing large extra dimension scenarios within the context of non-supersymmetric string models. Our analysis reveals an appealing mechanism to dynami

Qun Wang, Gösta Gustafson, Yi Jin, Qu-bing Xie

We use the method of the color effective Hamiltonian to study the structure of color singlet chain states in $N_c=3$ and in the large $N_c$ limit. In order to obtain their total fraction when $N_c$ is finite, we illustrate how to orthogonalize these non-orthogonal states. We give numerical results for the fraction of orthogonalized states in $e^+e^-\to q\bar

Roy Maartens, Varun Sahni, Tarun Deep Saini

We examine the behavior of an anisotropic brane-world in the presence of inflationary scalar fields. We show that, contrary to naive expectations, a large anisotropy does not adversely affect inflation. On the contrary, a large initial anisotropy introduces more damping into the scalar field equation of motion, resulting in greater inflation. The rapid decay

J. Stuhler, P. O. Schmidt, S. Hensler, J. Werner

We have realized a scheme for continuous loading of a magnetic trap (MT). ^{52}Cr atoms are continuously captured and cooled in a magneto-optical trap (MOT). Optical pumping to a metastable state decouples atoms from the cooling light. Due to their high magnetic moment (6 Bohr magnetons), low-field seeking metastable atoms are trapped in the magnetic quadrup

Yasushi Shimizu, Kensuke S. Ikeda, Shin-ichi Sawada

Microcanonical molecular dynamics study of the spontaneous alloying(SA), which is a manifestation of fast atomic diffusion in a nano-sized metal cluster, is done in terms of a simple two dimensional binary Morse model. Important features observed by Yasuda and Mori are well reproduced in our simulation. The temperature dependence and size dependence of the S

Da Qing Liu, Ji Ming Wu, Ying Chen

To calculate the mass of glueballs with quantum number $J^{PC}$ in lattice gauge theory by using Wilson loops, we discuss their combinations of Wilson loops into irreducible representation of $O^{PC}$ group for arbitry-link wilson loops. We present a general computational procedure for this combination which is suitable for any finite groups.

Manuel Drees, Yeong Gyun Kim, Tatsuo Kobayashi, Mihoko M. Nojiri

We compare predictions for the spin-independent contribution to the neutralino-proton scattering cross section $\sig$ and for the anomalous magnetic dipole moment of the muon, $a_μ= (g_μ-2)/2$, in models with gravity-mediated supersymmetry breaking. We nearly always find a positive correlation between these two measurables, i.e. scenarios with larger $a_μ$ a

Shinya Kanemura, Takashi Kasai, Guey-Lin Lin, Yasuhiro Okada

To generate small neutrino masses radiatively, the Zee-model introduces two Higgs doublets and one weak-singlet charged Higgs boson to its Higgs sector. From analyzing the renormalization group equations, we determine the possibile range of the lightest CP-even Higgs boson ($h$) mass and the Higgs boson self-couplings as a function of the cut-off scale beyon

Richard M. Neumann

A conceptual difficulty in the Hooke&#39;s-law description of ideal Gaussian polymer-chain elasticity is sometimes apparent in analyses of experimental data or in physical models designed to simulate the behavior of biopolymers. The problem, the tendency of a chain to collapse in the absence of external forces, is examined in the following examples: DNA-stre

Hiroaki Terao

Let $V$ be an $\ell$-dimensional Euclidean space. Let $G \subset O(V)$ be a finite irreducible orthogonal reflection group. Let ${\cal A}$ be the corresponding Coxeter arrangement. Let $S$ be the algebra of polynomial functions on $V.$ For $H \in {\cal A}$ choose $α_H \in V^*$ such that $H = {\rm ker}(α_H).$ For each nonnegative integer $m$, define the deriv

Dimitrios Psaltis

I study the formation of Comptonization spectra in spherically symmetric, fast moving media in a flat spacetime. I analyze the mathematical character of the moments of the transfer equation in the system-frame and describe a numerical method that provides fast solutions of the time-independent radiative transfer problem that are accurate in both the diffusio

Lajos Diosi

Unlike classical physics, quantum mechnanics is sensitive to mistaken choice of chiralities or time-arrows of local reference systems. Quantum correlations between distant electron spins, for instance, would reveal a mistaken local chirality. Local polarization measurements and classical communication enable the distant partners to compare their local chiral

E. Gudowska-Nowak, M. Kraemer, G. Kraft, G. Taucher-Scholz

According to the experimental evidence damage induced by densely ionizing radiation in mammalian cells is distributed along the DNA molecule in the form of clusters. The most critical constituent of DNA damage are double-strand breaks (DSBs) which are formed when the breaks occur in both DNA strands and are directly opposite or separated by only a few base p

Christian Siedschlag, Jan M Rost

For the energy absorption of atomic clusters as a function of the laser pulse duration we find a similar behavior as it has been observed for metallic clusters [Köller et al., Phys. Rev. Lett. {\bf 82}, 3783 (1999)]. In both situations there exists an optimum radius $R_{o}$ of the cluster for energy absorption. In the metallic case the existence of $R_{o}$ h

Naoki Watanabe, Masaru Tsukada

A fast and stable numerical method is formulated to compute the time evolution of a wave function in a magnetic field by solving the time-dependent Schroedinger equation. This computational method is based on the finite element method in real space to improved accuracy without any increase of computational cost. This method is also based on Suzuki&#39;s expo

Naoki Watanabe, Masaru Tsukada

A fast and stable method is formulated to compute the time evolution of a wavefunction by numerically solving the time-dependent Schr{ö}dinger equation. This method is a real space/real time evolution method implemented by several computational techniques such as Suzuki&#39;s exponential product, Cayley&#39;s form, the finite differential method and an opera

S. Shlomo, A. I. Sanzhur

We present results of microscopic calculations of the strength function, S(E), and alpha-particle excitation cross sections sigma(E) for the isoscalar giant dipole resonance (ISGDR). An accurate and a general method to eliminate the contributions of spurious state mixing is presented and used in the calculations. Our results provide a resolution to the long

A. Covello, L. Coraggio, A. Gargano, N. Itaco

The present paper is comprised of two parts. First, we give a brief survey of the theoretical framework for microscopic nuclear structure calculations starting from a free nucleon-nucleon potential. Then, we present some selected results of a comprehensive study of nuclei near doubly closed shells. In all these shell-model calculations we have made use of re

M. Goldhaber, R. Shrock

We analyze reactions of several types that are naively below threshold but can proceed because of the release of binding energy from nuclear fission and occasionally the formation of Coulombic bound states. These reactions include (i) photofission with pion production and (ii) charged current neutrino-nucleus reactions that lead to fission and/or formation o

E. Garrido, P. Sarriguren, E. Moya de Guerra, U. Lombardo

Recent published data on the isoscalar gap in symmetric nuclear matter using the Paris force and the corresponding BHF single particle dispersion are corrected leading to an extremely high proton-neutron gap of $Δ\sim 8$ MeV at $ρ\sim 0.5ρ_0$. Arguments whether this value can be reduced due to screening effects are discussed. A density dependent delta intera

V. Meden, K. Schoenhammer

In the context of nuclear physics Pratt recently investigated noninteracting Fermi systems described by the microcanonical and canonical ensemble. As will be shown his discussion of the model of equally spaced levels contains a flaw and a statement which is at least confusing.

E. Alvarez-Lacalle, J. Casademunt, J. Ortin

We develop a systematic method to derive all orders of mode couplings in a weakly nonlinear approach to the dynamics of the interface between two immiscible viscous fluids in a Hele-Shaw cell. The method is completely general. It includes both the channel geometry driven by gravity and pressure, and the radial geometry with arbitrary injection and centrifuga

Christian Hainzl

This paper is divided into two parts. In the first one the von Weizsäcker term is introduced to the Magnetic TF theory and the resulting MTFW functional is mathematically analyzed. In particular, it is shown that the von Weizsäcker term produces the Scott correction up to magnetic fields of order $B \ll Z^2$, in accordance with a result of V. Ivrii on the qu

N. P. Landsman

It is well known that a measured groupoid G defines a von Neumann algebra W*(G), and that a Lie groupoid G canonically defines both a C*-algebra C*(G) and a Poisson manifold A*(G). We show that the maps G -> W*(G), G -> C*(G) and G -> A*(G) are functorial with respect to suitable categories. In these categories Morita equivalence is isomorphism of objects, s

E. Frenkel, D. Gaitsgory, K. Vilonen

Let G be a split connected reductive group over a finite field F_q, and N its maximal unipotent subgroup. V. Drinfeld has introduced a remarkable partial compactification of the moduli stack of N-bundles on a smooth projective curve X over F_q. In this paper we study Drinfeld&#39;s moduli space and a certain category of perverse sheaves on it. The definition

Harm Voskuil

Let G be an absolutely almost simple algebraic group defined over a non-archimedean local field K. Let X be a projective homogeneous variety for G and let L be an ample line bundle on X. Then there exists a unique G-linearisation of L. We regard X as a rigid analytic variety. We consider the open rigid analytic subspace Y (resp. Y&#39;) of X that consists of

Luis Baez-Duarte

The paper presents two arithmetical versions of the Nyman-Beurling equivalence with the Riemann hypothesis, proved by classical, quasi elementary, number-theoretic methods, based on an integrated version of the classical combinatorial identity for Moebius numbers. These proofs also give insight into the troublesome phenomenon that many natural sequences of B

Noam D. Elkies

We answer a question posed in [Elkies 1996] (math.CO/9905198) by constructing a class of pawn endgames on m-by-n boards that show the Nimbers *k for large k. We do this by modifying and generalizing T.R. Dawson&#39;s ``pawns game&#39;&#39; [Berlekamp et al. 1982] (Winning Ways I). Our construction works for m>8 and n sufficiently large; on the basis of compu

Steven R. Costenoble

We consider four categories: the category of diagrams of small categories indexed by a given small category O, the (comma) category of small categories over O, the category of diagrams of simplicial sets indexed by O, and the category of simplicial sets over the nerve of O. Fritsch and Golasinski claimed that these four categories have equivalent homotopy ca

Kurt Johansson

We investigate certain measures induced by families of non-intersecting paths in domino tilings of the Aztec diamond, rhombus tilings of an abc-hexagon, a dimer model on a cylindrical brick lattice and a growth model. The measures obtained, e.g. the Krawtchouk and Hahn ensembles, have the same structure as the eigenvalue measures in random matrix theory like

Antonio F. Costa, Sergei M. Natanzon

Let $\widetilde{S}$ be a closed (compact without boundary) oriented surface with genus $g$, and $G$ be a group isomorphic to $% \mathbf{Z}_{p}^{m}$, where $p$ is a prime integer. An action of $G$ on $S$ is a pair $(\widetilde{S},f)$, where $f$ is a representation of $G$ in the group of orientation preserving autohomeomorphisms of $\widetilde{S}$. Two actions

Michael Cowling, Terence Tao

The purpose of this note is to correct an error in a paper of M. Cowling, G. Fendler and J.J.F. Fournier, and to give a counterexample to a conjecture of J.-L. Rubio de Francia.

A. Weber, J. C. Lopez Vieyra, C. R. Stephens, S. Dilcher

The calculation of bound state properties using renormalization group techniques to compute the corresponding Regge trajectories is presented. In particular, we investigate the bound states in different charge sectors of a scalar theory with interaction (phi^dagger phi chi). The resulting bound state spectrum is surprisingly rich. Where possible we compare a

A. Rajaraman

We construct supergravity solutions for Dp-branes at orbifold points. The solutions are written in terms of a single function, which is the solution to a nonlinear differential equation. The near horizon limits of these solutions are dual, in the AdS/CFT sense, to super-Yang-Mills theories with 8 supercharges in various dimensions. In particular, we present

S. A. Larin

The universal method of expansion of integrals is suggested. It allows in particular to derive the threshold expansion of Feynman integrals.

R. Jackiw

Chern-Simons terms are well-known descendants of chiral anomalies, when the latter are presented as total derivatives. Here I explain that also Chern-Simons terms, when defined on a 3-manifold, may be expressed as total derivatives.

R. Jackiw

John Bell&#39;s emphasis of the essential ambiguities in anomaly calculations is recalled. Some descendants of the anomaly are reviewed.

Alfred Scharff Goldhaber, Andrei Litvintsev, Peter van Nieuwenhuizen

We review our work on computations of the quantum corrections to the mass and the central charge of the susy kink. For the mass corrections, we find that the widely used momentum cut-off scheme gives an incorrect result, but we deduce through smoothing of the cut-off an extra term in the mass formula, which produces the correct result. We discover the import

Vanicson L. Campos, Gabriele Ferretti, Per Salomonson

We construct the scalar profile for the non-abelian self dual string connecting two M5-branes compactified on a light-like circle. The construction is based on a conjectured modified version of Nahm&#39;s equations describing a D2-brane, with a magnetic field on it, suspended between two D4-branes. Turning on a constant magnetic field on the D2-brane corresp

M. A. Lledó

Field theories on &#34;quantum&#34; or deformed space-time are considered here. The Moyal-Weyl deformation breaks the Lorentz invariance of the theory, but one can still require invariance under the supertranslation algebra. We investigate some aspects of the Wess-Zumino model, super Yang-Mills theories and analyze the correspondence of the later with the su

Denis Perrot

We use some BRS techniques to construct Chern-Simons forms generalizing the Chern character of K_1 groups in the Cuntz-Quillen description of cyclic homology.

M. Cadoni, P. Carta, D. Klemm

We discuss the large N limit of Calogero-Moser models for the classical infinite families of simple Lie algebras A_N, B_N, C_N and D_N. We show that the limit defines two different Conformal Field Theories with central charge c>1. The value of c and the dimension of the primary field are dictated by the underlying algebraic symmetries of the model.

Heinrich Saller

The hypercharge-isospin-color symmetry of the standard model interaction is drastically reduced to a remaining Abelian electromagnetic $\U(1)$-symmetry for the particles. It is shown that such a symmetry reduction comes as a consequence of the central correlation in the internal group as represented by the standard fields where the hypercharge properties are

E. A. Bergshoeff, M. de Roo, A. Sevrin

We review an iterative construction of the supersymmetric non-abelian Born-Infeld action. We obtain the action through second order in the fieldstrength. Kappa-invariance fixes the ordenings which turn out to deviate from the symmetrized trace proposal.

Hisashi Echigoya, Tadashi Miyazaki

A general action is proposed for the fields of $q$-dimensional differential form over the compact Riemannian manifold of arbitrary dimensions. Mathematical tools are based on the well-known de Rham-Kodaira decomposing theorem on harmonic integral. A field-theoretic action for strings, $p$-branes and high-spin fields is naturally derived. We also have, natura

Albert Schwarz

I review my results about noncommutative gauge theories and about the relation of these theories to M(atrix) theory following my lecture on ICMP 2000.

Albert Schwarz

Following my plenary lecture on ICMP2000 I review my results concerning two closely related topics: topological quantum field theories and the problem of quantization of gauge theories. I start with old results (first examples of topological quantum field theories were constructed in my papers in late seventies) and I come to some new results, that were not

Miao Li

Noncommutative solitons are easier to find in a noncommutative field theory. Similarly, the one-loop quantum corrections to the mass of a noncommutative soliton are easier to compute, in a real scalar theory in 2+1 dimensions. We carry out this computation in this paper. We also discuss the model with a double-well potential, and conjecture that there is a p

D. Z Freedman, P. Henry-Labordere

A survey of ideas, techniques and results from d=5 supergravity for the conformal and mass-perturbed phases of d=4 ${\cal N}$=4 Super-Yang-Mills theory

A. V. Radyushkin

Applications of perturbative QCD to deeply virtual Compton scattering and hard exclusive electroproduction processes require a generalization of usual parton distributions for the case when long-distance information is accumulated in nonforward matrix elements of quark and gluon light-cone operators. We describe two types of nonperturbative functions paramet

Stephen P. Martin, James D. Wells

We consider the possibility that some supersymmetric gauge theories which are not asymptotically free can be governed by ultraviolet-stable fixed points. If this scenario can be realized, gaugino masses will exhibit power-law running with scale, providing a possible solution to the supersymmetric flavor problem. While naive perturbative calculations hint at

F. Hautmann

We discuss recent work on methods for incorporating nonleading QCD corrections in parton shower algorithms.

J. C. Romao

We review supersymmetry models with and without R-parity. After briefly describing the Minimal Supersymetric Standard Model and its particle content we move to models where R-parity is broken, either spontaneously or explicitly. In this last case we consider the situation where R-parity is broken via bilinear terms in the superpotential. The radiative breaki

Roland Kaiser

The U(2)_R x U(2)_L symmetry of QCD with two massless flavours is subject to anomalies which affect correlation functions involving the singlet currents A^0_μor V^0_μ. These are relevant for pion-photon interactions, because - for two flavours - the electromagnetic current contains a singlet piece. We give the effective Lagrangian required for the correspond

B. -J. Schaefer, O. Bohr, J. Wambach

Self-consistent new renormalization group flow equations for an O(N)-symmetric scalar theory are approximated in next-to-leading order of the derivative expansion. The Wilson-Fisher fixed point in three dimensions is analyzed in detail and various critical exponents are calculated.