January 2000 arXiv papers — page 21

Gao Shan

We show that everyone can understand quantum mechanics, only if he rejects the following prejudice, namely classical continuous motion (CCM) is the only possible and objective motion of particles.

Victor I. Matveev

A general expression for the spectrum of photons emitted by atom at sudden perturbation is obtained. Some concrete examples of application of the obtained result are considered. The conclusion about the coherence of radiation of the atomic electrons under the such influences is made. PACS numbers: 32.30.*

F. Grassi, O. Socolowski

We show that a hydrodynamical model with continuous particle emission instead of sudden freeze out can explain both the strange particle abundances and pion abundance from NA35 without extra assumption (e.g., sequential freeze out, modified equation of state, sudden plasma hadronization,...). In this scenario, the observation of a larger pion abundance is na

S. Rajesh, G. Ananthakrishna

A characteristic feature of the Portevin - Le Chatelier effect or the jerky flow is the stick-slip nature of stress-strain curves which is believed to result from the negative strain rate dependence of the flow stress. The latter is assumed to result from the competition of a few relevant time scales controlling the dynamics of jerky flow. We address the iss

Eckehard Olbrich, Rainer Hegger, Holger Kantz

We present a method to derive an upper bound for the entropy density of coupled map lattices with local interactions from local observations. To do this, we use an embedding technique being a combination of time delay and spatial embedding. This embedding allows us to identify the local character of the equations of motion. Based on this method we present an

Palle E. T. Jorgensen, Daniil P. Proskurin, Yurii S. Samoilenko

It is shown that the kernel of the Fock representation of a certain Wick algebra with braided operator of coefficients T, || T ||<= 1, coincides with the largest quadratic Wick ideal. Improved conditions on the operator T for the Fock inner product to be strictly positive are given.

Palle E. T. Jorgensen, Gestur Ólafsson

The mathematical axiom systems for quantum field theory grew out of Hilbert&#39;s sixth problem, that of stating the problems of quantum theory in precise mathematical terms. There have been several competing mathematical systems of axioms, and here we shall deal with those of A.S. Wightman and of K. Osterwalder and R. Schrader, stated in historical order. T

G. van der Geer, T. Katsura

In this paper we consider the stratification on the moduli space of principally polarized abelian surfaces in characteristic $p>0$ defined by the height of the formal group associated to $H^2(X,O_X)$. We compute the cycle classes of the strata and compare these with those of the $p$-rank stratification.

G. van der Geer, T. Katsura

In this paper we give a characterization of the height of K3 surfaces in positive characteristic. This enables us to calculate the cycle classes of the loci in families of K3 surfaces where the height is at least h. The formulas for such loci can be seen as generalizations of the famous formula of Deuring for the number of supersingular elliptic curves in po

Susumu Ariki

These are lecture notes prepared for London Mathematical Society Symposium &#34;Quantum Groups&#34; held in Durham 19-29 July 1999. We give a survey on cyclotomic Hecke algebras. These algebras have been studied by Dipper, James, Malle, Mathas and the author. In lecture one, we start with definitions. We then go on to Specht module theory of cyclotomic Hecke

Susumu Ariki

We give a proof of a conjecture that Kleshchev multipartitions are those partitions which parametrize non-zero simple modules obtained as factor modules of Specht modules by their own radicals.

Harold P. Boas

This article discusses questions in one and several complex variables about the size of the sum of the moduli of the terms of the series expansion of a bounded holomorphic function. Although the article is partly expository, it also includes some previously unpublished results with complete proofs. The article is based on a lecture at the third Korean severa

Harold P. Boas

This expository article, intended to be accessible to students, surveys results about the presence or absence of zeroes of the Bergman kernel function of a bounded domain in C^n. Six open problems are stated. The article is based on a lecture at the third Korean several complex variables symposium held at the Global Analysis Research Center at Seoul National

D. B. A. Epstein, P. J. Sanders

It is shown how to use a small finite state automaton in two variables in order to carry out the Knuth-Bendix process for rewriting words in a group in shortlex order. The two-variable automaton can be used to store an infinite set of rules and to carry out fast reduction of arbitrary words using this infinite set. We introduce a new operation, which we call

D. Arnaudon, J. Avan, L. Frappat, E. Ragoucy

We construct universal twists connecting the centrally extended double Yangian DY(sl(2))_c with deformed double Yangians DY_r(sl(2))_c, thereby establishing the quasi-Hopf structures of the latter.

Masatoshi Noumi, Jasper V. Stokman

We study Askey-Wilson type polynomials using representation theory of the double affine Hecke algebra. In particular, we prove bi-orthogonality relations for non-symmetric and anti-symmetric Askey-Wilson polynomials with respect to a complex measure. We give duality properties of the non-symmetric Askey-Wilson polynomials, and we show how the non-symmetric A

Denis V. Juriev

This article is devoted to the tactical game theoretical interpretation of dialectics. Dialectical games are considered as abstractly as well as models of the internal dialogue and reflection. The models related to the representation theory (representative dynamics) are specially investigated in detail, they correlate with the hypothesis on the dialectical f

Scott H. Murray

We compute conjugacy classes in maximal parabolic subgroups of the general linear group. This computation proceeds by reducing to a ``matrix problem&#39;&#39;. Such problems involve finding normal forms for matrices under a specified set of row and column operations. We solve the relevant matrix problem in small dimensional cases. This gives us all conjugacy

Bogdan Damski

We take advantage of the superspace formalism and explicitly find the N=2 supersymmetric extension of the Maxwell Chern-Simons model. In our construction a special form of a potential term and indispensability of an additional neutral scalar field arise naturally. By considering the algebra of supersymmetric charges we find Bogomol'nyi equations for the inve

Horace W. Crater, Peter Van Alstine

We review a little-known treatment of the relativistic two-body bound-state problem - that provided by Two-Body Dirac Equations obtained from constraint dynamics. We describe some of its more important results, its relation to older formulations and to quantum field theory. We list a number of features crucial for the success of such a formulation, many of w

Jen-Chieh Peng, Gerald T. Garvey

Recent deep inelastic scattering and Drell-Yan experiments have revealed a surprisingly large asymmetry between the up and down sea quark distributions in the nucleon. In this article, we review the status of the flavor asymmetry of the nucleon sea. The implications of the recent results on various theoretical models as well as possible future measurements a

S. M. Barr, C. H. Albright

A general approach to understanding the large mixing seen in atmospheric neutrinos is explained, as well as a highly predictive SO(10) model which implements this approach. It is also seen how bimaximal mixing naturally arises in this scheme. (Talk presented at NNN99, SUNY Stony Brook, Sept. 22-26, 1999)

K. Rabbertz

Deep-inelastic ep scattering data, taken with the H1 detector at HERA, are used to study event shape variables over a large range of &#34;relevant energy&#34; Q between 7 GeV and 100 GeV. Previously published analysis on thrust, jet broadening, jet mass and C parameter are substantially refined and updated; differential two-jet rates treated as event shapes

G. R. Kerley, M. McDermott

We explain why it is possible to formulate a wide variety of high energy (small-x) photon-proton processes in terms of a universal dipole cross section and compare and contrast various parameterizations of this function that exist in the literature.

Guenter Sigl

Some solutions of the hierarchy problem of particle physics can lead to significantly increased neutrino cross sections beyond the electroweak scale. We discuss some consequences for and constraints resulting from cosmic ray physics.

Vojtech Kundrat, Milos Lokajicek, D. Krupa

The elastic and inelastic profiles have been derived from the measured elastic differential cross section data with the help of exact impact parameter representation of elastic scattering amplitude. The results obtained for $pp$ scattering at energy of 53 GeV and $\bar{p} p$ scattering at energy of 541 GeV have been presented. They indicate that nucleons can

Y. Goto, N. Hayashi, M. Hirai, H. Horikawa

Polarized parton distribution functions are determined by using world data from the longitudinally polarized deep inelastic scattering experiments. A new parametrization of the parton distribution functions is adopted by taking into account the positivity and the counting rule. From the fit to the asymmetry data A_1, the polarized distribution functions of u

L3 Collaboration

The three different helicity states of W bosons, produced in the reaction e+e- -> W+W- -> l nu q q~ are studied using leptonic and hadronic W decays at sqrt{s}=183GeV and 189GeV. The W polarisation is also measured as a function of the scattering angle between the W- and the direction of the e- beam. The analysis demonstrates that W bosons are produced with

G. A. Alekseev

In this paper the well known Belinskii and Zakharov soliton generating transformations of the solution space of vacuum Einstein equations with two-dimensional Abelian groups of isometries are considered in the context of the so called "monodromy transform approach", which provides some general base for the study of various integrable space - time symmetry re

Philip D. Mannheim

We discuss the circumstances under which gravity might be repulsive rather than attractive. In particular we show why our standard solar system distance scale gravitational intuition need not be a reliable guide to the behavior of gravitational phenomena on altogether larger distance scales such as cosmological, and argue that in fact gravity actually gets t

Oleg Kiselyov

With no intent of starting a holy war, this paper lists several annoying C++ birthmarks that the author has come across developing GUI class libraries. C++&#39;s view of classes, instances and hierarchies appears tantalizingly close to GUI concepts of controls, widgets, window classes and subwindows. OO models of C++ and of a window system are however differ

S. R. Mishra, H. S. Rawat, S. C. Mehendale, K. C. Rustagi

Optical limiting behaviour of suspensions of single-walled carbon nanotubes in water, ethanol and ethylene glycol is reported. Experiments with 532 nm, 15 nsec duration laser pulses show that optical limiting occurs mainly due to nonlinear scattering. The observed host liquid dependence of optical limiting in different suspensions suggests that the scatterin

Jonathan Doye

Recently, Locatelli and Schoen proposed a transformation of the potential energy that aids the global optimization of Lennard-Jones clusters with non-icosahedral global minima. These cases are particularly difficult to optimize because the potential energy surface has a double funnel topography with the global minimum at the bottom of the narrower funnel. He

M. Roy, J. F. Mitchell, P. Schiffer

The ground state of La_{1-x}Ca_{x}MnO_{3} changes from a ferromagnetic metallic to an antiferromagnetic charge-ordered state as a function of Ca concentration at x ~ 0.50. We present evidence from transport measurements on a sample with x = 0.50 that the two phases can coexist, in agreement with other observations of phase separation in these materials. We a

Antoine Georges, Thierry Giamarchi, Nancy Sandler

We reconsider the theory of dc and ac interchain conductivity in quasi-one dimensional systems. Our results are in good agreement with the measured c-axis optical conductivity of (TMTSF)_2{ClO}_4 and suggest that the c-axis dc-conductivity of (TMTSF)_2{PF}_6 in the 150K < T < 300Kd$ range is dominated by precursor effects of Mott localization. The crossover

A. V. Rozhkov, Daniel P. Arovas

We investigate the Josephson coupling between two superconductors mediated through an infinite U Anderson impurity, adapting a variational wavefunction approach which has proved successful for the Kondo model. Unlike the Kondo problem, however, a crossing of singlet and doublet state energies may be produced by varying the ratio of Kondo energy to supercondu

M. Schreiber, D. Kilin

A non-Markovian master equation for a molecule interacting with a heat bath is obtained using the cumulant expansion method. The equation is applied to the problem of molecular wave packet relaxtional dynamics. An exact solution is derived that demonstrates classical type of squeezing for the wave packet evolution and a heat-bath dependent frequency shift.

M. T. Velhinho, I. R. Pimentel

We study the Lyapunov exponent for electron and phonon excitations, in pure and random Fibonacci quasicrystal chains, using an exact real space renormalization group method, which allows the calculation of the Lyapunov exponent as a function of the energy. It is shown that the Lyapunov exponent on a pure Fibonacci chain has a self-similar structure, characte

K. Y. L. Su, S. Kwok, B. J. Hrivnak, R. Sahai

We report NICMOS wide-band and polarimetric observations of four proto-planetary nebulae. Molecular hydrogen emission is detected near the ends of the bipolar lobes of IRAS 17150-3224, which is evidence for the interaction of a fast, collimated outflow with the remnant of the asymptotic giant branch wind.

A. J. Barger, L. L. Cowie, E. A. Richards

Direct submm imaging has recently revealed the 850-micron background to be mostly composed of a population of distant ultraluminous infrared galaxies, but identifying the optical/NIR counterparts to these sources has proved difficult due to the poor submm spatial resolution. However, the proportionality of both cm and submm data to the star formation rate su

Wei Cui, Shuang Nan Zhang, Wan Chen

We report the results from measuring the phase lag and coherence function of X-ray emission from black hole candidate (BHC) XTE J1550-564. These X-ray temporal properties have been recognized to be increasingly important in providing important diagnostics of the dynamics of accretion flows around black holes. For XTE J1550-564, we found significant hard lag

Jonathan D. Slavin, Christopher F. McKee, David J. Hollenbach

We present new calculations on the contribution from cooling hot gas to the photoionization of warm ionized gas in the Galaxy. We show that hot gas in cooling supernova remnants (SNRs) is an important source of photoionization, particularly for gas in the halo. We find that in many regions at high latitude this source is adequate to account for the observed

Peter Berczik

The chemical and photometric evolution of star forming disk galaxies is investigated. Numerical simulations of the complex gasdynamical flows are based on our own coding of the Chemo - Dynamical Smoothed Particle Hydrodynamical (CD - SPH) approach, which incorporates the effects of star formation. As a first application, the model is used to describe the che

C. D. Gill, T. J. O&#39;Brien

In this paper we report on the first five out of eleven observations in our programme of Hubble Space Telescope (HST) imaging of old nova shells. We present new WFPC2 images of the shells around FH Ser and V533 Her taken in the F656N (Halpha+[NII]) filter. We also show long-slit spectra taken using the William Herschel Telescope (WHT) in La Palma for these o

M. J. Pivovaroff, V. M. Kaspi, F. Camilo

PSR J1814-1744 is a 4 s radio pulsar with surface dipole magnetic field strength 5.5*10^13 G, inferred assuming simple magnetic dipole braking. This pulsar&#39;s spin parameters are very similar to those of anomalous X-ray pulsars (AXPs), suggesting that this may be a transition object between the radio pulsar and AXP population, if AXPs are isolated, high m

T. A. A. Sigut, J. D. Landstreet, S. L. S. Shorlin

Emission in the 4d - 4f transitions of MnII (multiplet 13, 6122-6132 Ang), in the 4f - 6g transitions of PII, and in 6149.5 Ang of HgII has been detected in the spectrum of the helium weak star 3 Centauri A (B5 III-IVp). Weaker emission from the same MnII multiplet is also seen in the hot, mild HgMn star 46 Aquila (B9 III).It is suggested that the emission i

Pauline Barmby, John P. Huchra

We have measured an extensive set of UBVRIJHK colors for M31 globular clusters [Barmby et al. 2000]. We compare the predicted simple stellar population colors of three population synthesis models to the intrinsic colors of Galactic and M31 globular clusters. The best-fitting models fit the cluster colors very well -- the weighted mean color offsets are all <

Guo Xin Chen, Anil K. Pradhan

Fluorescent excitation of spectral lines is demonstrated as a function of temperature-luminosity and the distance of the emitting region from the central stars of planetary nebulae. The electron densities and temperatures are determined, and the method is exemplified through a detailed analysis of spectral observations of a high excitation PN, NGC 6741, obse

G. L. Israel, S. Covino, S. Campana, V. F. Polcaro

We report the discovery of the optical/infra-red counterpart of the 12.3s transient X-ray pulsar GS0834-43. We re-analysed archival ROSAT PSPC observations of GS0834-43, obtaining two new refined positions, about 14&#34; and 18&#34; away from the previously published one, and a new spin period measurement. Within the new error circles we found a relatively f

Diego Harari, Silvia Mollerach, Esteban Roulet

We analyse several implications of lensing by the regular component of the galactic magnetic field upon the observed properties of ultra high energy cosmic rays. Magnetic fields deflect cosmic ray trajectories, causing flux (de)magnification, formation of multiple images of a single source, and time delays. We derive the energy dependence of these effects ne

EROS Collaboration

We present an analysis of the light curves of 9.1 million stars observed during three seasons by EROS (Experience de Recherche d&#39;Objets Sombres), in the Galactic plane away from the bulge. Seven stars exhibit luminosity variations compatible with gravitational microlensing effects due to unseen objects. The corresponding optical depth, averaged over four

K. Reinsch, A. van Teeseling, A. R. King, K. Beuermann

We present new results of our X-ray monitoring of the transient binary supersoft X-ray source RX J0513.9-6951 in the LMC and of our re-analysis of optical light curves obtained during the MACHO project. We have covered a complete X-ray outburst cycle with the ROSAT HRI detector. From the amplitude and timescale of the soft X-ray variability, tight limits are

Sabine Schindler

We analyse three clusters of galaxies, Abell 901 (z=0.17), Abell 1437 (z=0.13) and Abell 3570 (z=0.037). They have low to intermediate X-ray fluxes and an irregular morphology in the ROSAT All-Sky Survey (RASS). These clusters are chosen to test the abilities and limitations of the RASS in terms of cluster fluxes and cluster morphologies. Therefore some ``wo

Sonali Chakrabarti, Sandip K. Chakrabarti

Using a reasonably large chemical reaction network consisting of 421 species, we show that along with normal chemical evolution of molecular cloud during collapse and star formation, significant amount of adenine, a DNA base, may be produced after an evolution of 10^{6-7} years. This findings may shed light on whether life on earth had to begin from scratch

M. H. van Kerkwijk

I review attempts made to determine the properties of neutron stars. The focus is on the maximum mass that a neutron star can have, or, conversely, the minimum mass required for the formation of a black hole. There appears to be only one neutron star for which there is strong evidence that its mass is above the canonical 1.4 solar masses, viz., Vela X-1, for

Kohji Yoshikawa, Y. P. Jing, Yasushi Suto

We present results from a series of cosmological SPH (smoothed particle hydrodynamics) simulations coupled with the P3M (Particle-Particle-Particle-Mesh) solver for the gravitational force. The simulations are designed to predict the statistical properties of X-ray clusters of galaxies as well as to study the formation of galaxies. We have seven simulation r

Max Pettini

It has recently become possible to measure directly the abundances of several chemical elements in a variety of environments at redshifts up to z = 5. In this review I summarise the latest observations of Lyman break galaxies, damped Lyman alpha systems and the Lyman alpha forest with a view to uncovering any clues which these data may offer to the first epi

Vikram Dwarkadas, Lewis Ball, James Caswell, Anne Green

We summarise the proceedings of the SRCfTA workshop on ``Supernova Remnants, Pulsars and the Interstellar Medium&#39;&#39; that was held at the University of Sydney on Mar 18 and 19, 1999.

M. Sevenster, H. Dejonghe, K. Van Caelenberg, H. J. Habing

We present dynamical distribution functions for evolved stars in the inner galactic plane. We use an axisymmetric, two-component Stackel potential that satisfies recent constraints on the galactic potential, amongst others a slightly declining local rotation curve. We show that this potential is adequate to model stellar-kinematic samples with radial extent

S. C. Trager, S. M. Faber, Guy Worthey, J. Jesus Gonzalez

We present single stellar population (SSP) equivalent ages, metallicities, and abundance ratios for local elliptical galaxies derived from Hbeta, Mgb, and <Fe> absorption line strengths. We use an extension of the Worthey (1994) stellar population models that incorporates non-solar line-strength &#34;response functions&#34; by Tripicco & Bell (1995), allowin

Zalan Horvath, Robert L. Karp, Laszlo Palla

We study the two loop quantum equivalence of sigma models related by Buscher&#39;s T-duality transformation. The computation of the two loop perturbative free energy density is performed in the case of a certain deformation of the SU(2) principal sigma model, and its T-dual, using dimensional regularization and the geometric sigma model perturbation theory.

U. Schneider, R. Brand, P. Lunkenheimer, A. Loidl

Dielectric loss spectra of glass-forming propylene carbonate and glycerol at temperatures above and below T_g are presented. By performing aging experiments lasting up to five weeks, equilibrium spectra below T_g have been obtained. During aging, the excess wing, showing up as a second power law at high frequencies, develops into a shoulder. The results stro

T. Appelquist, Z. Duan, F. Sannino

We discuss the behavior of two non-supersymmetric chiral SU(N) gauge theories, involving fermions in the symmetric and antisymmetric two-index tensor representations respectively. In addition to global anomaly matching, we employ a recently proposed inequality constraint on the number of effective low energy (massless) degrees of freedom of a theory, based o

D. Gomez Dumm, A. J. Garcia, N. N. Scoccola

Non-leptonic hyperon weak decays are investigated in the SU(3) Skyrme model. We use a collective coordinate scheme, following the approach in which the symmetry breaking terms in the strong effective action are diagonalized exactly. To describe the weak interactions we use an octet dominated weak effective lagrangian that leads to a good description of the k

Nickolay Y. Gnedin, Andrea Ferrara, Ellen G. Zweibel

We investigate the generation of magnetic field by the Biermann battery in cosmological ionization fronts, using new simulations of the reionization of the universe by stars in protogalaxies. Two mechanisms are primarily responsible for magnetogenesis: i) the breakout of I-fronts from protogalaxies, and ii) the propagation of I-fronts through the high densit

John Collins

In the case of the gluon-fusion process in deep-inelastic leptoproduction, I explicitly show how to incorporate NLO corrections in a Monte-Carlo event generator by a subtraction method. I calculate the parton densities to be used by the event generator in terms of MSbar densities. The method is generalizable. A particular motivation for treating the gluon-fu

Miles P. Blencowe, Vincenzo Vitelli

We show that the recently discovered universal upper bound on the thermal conductance of a single channel comprising particles obeying arbitrary fractional statistics is in fact a consequence of a more general universal upper bound, involving the averaged entropy and energy currents of a single channel connecting heat reservoirs with arbitrary temperatures a

Mark Mineev-Weinstein, Paul B. Wiegmann, Anton Zabrodin

We establish the equivalence of a 2D contour dynamics to the dispersionless limit of the integrable Toda hierarchy constrained by a string equation. Remarkably, the same hierarchy underlies 2D quantum gravity.

I. Klich, J. Feinberg, A. Mann, M. Revzen

The Casimir energy, free energy and Casimir force are evaluated, at arbitrary finite temperature, for a dilute dielectric ball with uniform velocity of light inside the ball and in the surrounding medium. In particular, we investigate the classical limit at high temperature. The Casimir force found is repulsive, as in previous calculations.

Donam Youm

We study the solution describing a non-extreme dilatonic (p+1)-brane intersecting a D-dimensional extreme dilatonic domain wall, where one of its longitudinal directions is along the direction transverse to the domain wall, in relation to the Randall-Sundrum type model. The dynamics of the probe (p+1)-brane in such source background reproduces that of the pr

SDSS Collaboration, Zlatan I. Tsvetanov

We report the discovery of a second field methane brown dwarf from the commissioning data of the Sloan Digital Sky Survey (SDSS). The object, SDSS J134646.45-003150.4 (SDSS 1346-00), was selected because of its very red color and stellar appearance. Its spectrum between 0.8-2.5 mic is dominated by strong absorption bands of H_2O and CH_4 and closely mimics t

Mathias van den Bossche, Fu-Chun Zhang, Frederic Mila

In order to understand the properties of Mott insulators with strong ground state orbital fluctuations, we study the zero temperature properties of the SU(4) spin-orbital model on a square lattice. Exact diagonalizations of finite clusters suggest that the ground state is disordered with a singlet-multiplet gap and possibly low-lying SU(4) singlets in the ga

A Donnachie, S Soldner-Rembold

The energy available for gamma(*)gamma(*) physics at LEP2 is opening a new window on the study of diffractive phenomena, both non-perturbative and perturbative. We discuss some of the uncertainties and problems connected with the experimental measurements and their interpretation.

E. L. Bratkovskaya, W. Cassing, C. Greiner, M. Effenberger

We study thermal and chemical equilibration in &#39;infinite&#39; hadron matter as well as in finite size relativistic nucleus-nucleus collisions using a BUU cascade transport model that contains resonance and string degrees-of-freedom. The &#39;infinite&#39; hadron matter is simulated within a cubic box with periodic boundary conditions. The various equilib

Enrique Alvarez, Cesar Gomez

The equivalence between the holographic renormalization group and the soft dilaton theorem is shown for a class of wrapped metrics solutions of the string beta function equations for the bosonic string.

F. Sattin

Absolute total cross sections for electron capture between slow, highly charged ions and alkali targets have been recently measured. It is found that these cross sections follow a scaling law with the projectile charge which is different from the one previously proposed basing on a classical over-barrier model (OBM) and verified using rare gases and molecule

F. Iwamuro, K. Motohara, T. Maihara, J. Iwai

We present the 2.12~$μ$m narrow-band image of the Hubble Deep Field North taken with the near-infrared camera (CISCO) on the Subaru telescope. Among five targets whose H$α$ or [O~{\sc iii}] emission lines are redshifted into our narrow-band range expected from their spectroscopic redshift, four of them have strong emission lines, especially for the two [O~{\

Greg Aldering, Robert Knop, Peter Nugent

We present a self-consistent comparison of the rise times for low- and high-redshift Type Ia supernovae. Following previous studies, the early light curve is modeled using a t-squared law, which is then mated with a modified Leibundgut template light curve. The best-fit t-squared law is determined for ensemble samples of low- and high-redshift supernovae by

P. Jain, Douglas W. McKay, S. Panda, John P. Ralston

Cosmic ray events above $10^{20}$ eV are on the verge of confronting fundamental particle physics. The neutrino is the only candidate primary among established particles capable of crossing 100 Mpc intergalactic distances unimpeded. The magnitude of $νN$ cross sections indicated by events, plus consistency with the Standard Model at low-energy, point to new

S. E. Csorna

Using 9.6 million B meson pairs collected with the CLEO detector, we have fully reconstructed 135 B0 -> psi(&#39;) K_S and 526 B+ -> psi(&#39;) K+ candidates with very low background. We fitted the psi(&#39;)K invariant mass distributions of these B meson candidates and measured the masses of the neutral and charged B mesons to be M(B0)=5279.1+-0.7[stat]+-0.

Ryoichi Yamamoto, Walter Kob

We investigate to what extend the replica-exchange Monte Carlo method is able to equilibrate a simple liquid in its supercooled state. We find that this method does indeed allow to generate accurately the canonical distribution function even at low temperatures and that its efficiency is about 10-100 times higher than the usual canonical molecular dynamics s

Israel Quiros

The initial singularity problem in standard general relativity is treated on the light of a viewpoint asserting that this formulation of Einstein&#39;s theory and its conformal formulations are physically equivalent. We show that flat Friedmann-Robertson-Walker universes and open dust-filled and radiation-filled universes are singularity free when described

Igor F. Herbut

I obtain the inverse of the correlation length exponent at the superfluid-Bose glass quantum critical point as a series in small parameter $\sqrt{d-1}$, with d being the dimensionality of the system, and compute the first two terms using a novel field-theoretic technique. For d=2 I find $ν_s = 0.81$ and $ν_c = 1.03$, for short-range and Coulomb interactions

Murray Peshkin

The analysis of phase shifts in executed and proposed interferometry experiments on photons and neutrons neglected forces exerted at the boundaries of spatial constrictions. When those forces are included it is seen that the observed phenomena are not in fact geometric in nature. A new proposal to be published by Allman et al. avoids that pitfall.

Susan B. Rempe, Lawrence R. Pratt, Gerhard Hummer, Joel D. Kress

A theoretical treatment based upon the quasi-chemical theory of solutions predicts the most probable number of water neighbors in the inner shell of a Li+ ion in liquid water to be four. The instability of a six water molecule inner sphere complex relative to four-coordinated structures is confirmed by an `ab initio&#39; molecular dynamics calculation. A cla

N. P. Andion, A. P. C. Malbouisson, A. Mattos Neto

Starting from a solution of the problem of a mechanical oscillator coupled to a scalar field inside a reflecting sphere of radius $R$, we study the behaviour of the system in free space as the limit of an arbitrarily large radius in the confined solution. From a mathematical point of view we show that this way of facing the problem is not equivalent to consi

T. S. Jensen, V. E. Markushin

We have calculated differential, total and transport cross sections for muonic hydrogen in the n=2 state scattering from hydrogen. The metastable fraction of the 2S state that slows down below the 2P threshold without undergoing collisional quenching has been calculated as a function of the initial kinetic energy using a Monte Carlo kinetics program. Contrar

H. Müther, A. Polls

Correlations in the nuclear wave-function beyond the mean-field or Hartree-Fock approximation are very important to describe basic properties of nuclear structure. Various approaches to account for such correlations are described and compared to each other. This includes the hole-line expansion, the coupled cluster or ``exponential S&#39;&#39; approach, the

V. V. Khodel, V. A. Khodel, J. W. Clark

The separation method developed earlier by us [Nucl. Phys. {\bf A598} 390 (1996)] to calculate and analyze solutions of the BCS gap equation for $^1$S$_0$ pairing is extended and applied to $^3$P$_2$--$^3$F$_2$ pairing in pure neutron matter. The pairing matrix elements are written as a separable part plus a remainder that vanishes when either momentum varia

R. Vitolo

We discuss intrinsic aspects of Krupka&#39;s approach to finite-order variational sequences. We give intrinsic isomorphisms of the quotient subsheaves of the short finite-order variational sequence with sheaves of forms on jet spaces of suitable order, obtaining a new finite-order (short exact) variational sequence which is made by sheaves of polynomial diff

Christian Fleischhack

The action of Ashtekar&#39;s generalized gauge group $\Gb$ on the space $\Ab$ of generalized connections is investigated for compact structure groups $\LG$. First a stratum is defined to be the set of all connections of one and the same gauge orbit type, i.e. the conjugacy class of the centralizer of the holonomy group. Then a slice theorem is proven on $\Ab

Christian Fleischhack

Properties of the space $\Ab$ of generalized connections in the Ashtekar framework are investigated. First a construction method for new connections is given. The new parallel transports differ from the original ones only along paths that pass an initial segment of a fixed path. This is closely related to a new notion of path independence. Although we do not

Christian Fleischhack

Different versions for defining Ashtekar&#39;s generalized connections are investigated depending on the chosen smoothness category for the paths and graphs -- the label set for the projective limit. Our definition covers the analytic case as well as the case of webs. Then the orbit types of the generalized connections are determined for compact structure gr

Ian McIntosh

This article shows that every non-isotropic harmonic 2-torus in complex projective space factors through a generalised Jacobi variety related to the spectral curve. Each map is composed of a homomorphism into the variety and a rational map off it. The same ideas allow one to construct (pluri)-harmonic maps of finite type from Euclidean space into Grassmannia

Peter Niemann

Starting from Borcherds&#39; fake monster Lie algebra we construct a sequence of six generalized Kac-Moody algebras whose denominator formulas, root systems and all root multiplicities can be described explicitly. The root systems decompose space into convex holes, of finite and affine type, similar to the situation in the case of the Leech lattice. As a cor

J. Gratus

A non associative, noncommutative algebra is defined that may be interpreted as a set of vector modules over a noncommutative surface of rotation. Two of these vector modules are identified with the analogues of the tangent and cotangent spaces in noncommutative geometry, via the definition of an exterior derivative. This derivative reduces to the standard e

Piotr Kobak, Andrew Swann

It is known that nilpotent orbits in a complex simple Lie algebra admit hyperKähler metrics with a single function that is a global potential for each of the Kähler structures (a hyperKähler potential). In an earlier paper the authors showed that nilpotent orbits in classical Lie algebras can be constructed as finite-dimensional hyperKähler quotient of a fla

Martin Lorenz, Zinovy Reichstein

Let k be an algebraically closed field of characteristic 0 and let D be a division algebra whose center F contains k. We shall say that D can be reduced to r parameters if D = D_0 tensor_{F_0} F, where D_0 is a division algebra, the center F_0 of D_0 contains k and trdeg(F_0/k) = r. We show that every division algebra of odd degree n >= 5 can be reduced to a

Piotr Kobak, Andrew Swann

Let G be a compact simple Lie group and the O the minimal nilpotent orbit in g^C. We determine all G-invariant Kähler potentials for hyperKähler metrics compatible with the KKS complex symplectic form on O.

Piotr Kobak, Andrew Swann

A hyperKähler potential is a function rho that is a Kähler potential for each complex structure compatible with the hyperKähler structure. Nilpotent orbits in a complex simple Lie algebra are known to carry hyperKähler metrics admitting such potentials. In this paper, we explicitly calculate the hyperKähler potential when the orbit is of cohomogeneity two. I