April 2002 arXiv papers — page 7

Rudolph C. Hwa, C. B. Yang

Inclusive distributions of soft production of mesons in hadronic collisions are calculated in the valon-recombination model. The new determination of the valon distributions from hard scattering data makes possible a tightly interrelated treatment of pion and kaon production in the fragmentation regions of proton, pion and kaon. Only one free parameter is us

V. Shevchenko, Yu. Simonov

Nonperturbative and perturbative interaction mechanisms of Wilson loops in gluodynamics are studied within the background field formalism. The first one operates when distance between minimal surfaces of the loops is small and may be important for sea quark effects and strong decay processes. The second mechanism -- perturbative interaction in nonperturbativ

Johann H. Kuhn, German Rodrigo

Virtual corrections for electron--positron annihilation into one real and one off-shell photon of invariant mass Q^2 are evaluated. Special attention is paid to those configurations where the real photon is collinear with the beam direction. This calculation is an important ingredient of a Monte Carlo program, which simulates events with tagged photons from

Chao-Hsi Chang, A. K. Giri, Rukmani Mohanta, Guo-Li Wang

The possible transverse polarization of the $τ$-lepton, which is $T$-odd and can be used to measure CP-violation, is estimated precisely in the radiative decay mode $B_c \to τ\bar ν_τγ$ with possible parameters for the multi Higgs doublet model and the R-parity violating supersymmetric model. We find that the up-bound of the transverse polarization with poss

Fedor Simkovic, Pavol Domin, Amand Faessler

In view of recent great progress achieved in the experimental study of the neutrinoless double beta decay (0nbb-decay) of 134Xe we discuss theoretical aspects of this process. The light and heavy Majorana neutrino exchange as well as the trilinear R-parity breaking contributions to 0nbb-decay are considered. We show that the sensitivity of the studied proces

Alex Kovner, Urs Achim Wiedemann

We show that perturbation theory provides two distinct mechanisms for the power like growth of hadronic cross sections at high energy. One, the leading BFKL effect is due to the growth of the parton density, and is characterized by the leading BFKL exponent. The other mechanism is due to the infrared diffusion, or the long range nature of the Coulomb field o

Xu Qing-hua, Liu Chun-xiu, Liang Zuo-tang

The recent data on the polarization of vector meson at LEP show that the vector mesons favor the helicity zero state. We calculate the helicity density matrix of vector meson which contains a polarized fragmenting quark by adding the spin of the fragmenting quark and that of the antiquark created in the fragmentation. The data at LEP imply a significant pola

J. C. Montero, V. Pleitez, M. C. Rodriguez

The goal of this article is to outline the advantages of the measurement of left-right asymmetries in lepton-lepton ($l^{-}l^{-}\to l^{-}l^{-}$) scattering for performing precision measurements of $\sin^2 θ_W$ and the discovery of ``new physics''.

Paolo Cea, Leonardo Cosmai

We study vacuum dynamics of SU(3) lattice gauge theory at finite temperature using the lattice Schrödinger functional. The SU(3) vacuum is probed by means of an external constant Abelian chromomagnetic field. We find that by increasing the strength of the applied external field the deconfinement temperature decreases towards zero. This means that strong enou

Shinji Ejiri, Shouji Fujimoto, Jisuke Kubo

Monte Carlo simulations are performed in a five-dimensional lattice SU(2) Yang-Mills theory with a compactified extra dimension, and scaling laws are studied. Our simulations indicate that as the compactification radius $R$ decreases, the confining phase spreads more and more to the weak coupling regime, and the effective dimension of the theory changes grad

J. G. Kim, S. M. Dardin, K. H. Jackson, R. W. Kadel

Electron avalanching in liquid argon is being studied as a function of voltage, pressure, radiation intensity, and the concentrations of certain additives, especially xenon. The avalanches produced in an intense electric field at the tip of a tungsten needle are initiated by ionization from a moveable americium (241Am) gamma ray source. Photons from xenon ex

T. Greenshaw, M. Klein

A summary is given of the recent Durham workshop on the future of lepton-nucleon scattering. Discussions at the workshop centred on the need to ensure that an international scientific and technical programme is developed with the goal of further exploring the structure of the nucleon. Questions of particular interest include the investigation of nucleon stru

Giovanni Amelino-Camelia, Y. Jack NG, Hendrik Van Dam

A growing number of studies is being devoted to the identification of plausible quantum properties of spacetime which might give rise to observably large effects. The literature on this subject is now relatively large, including studies in string theory, loop quantum gravity and noncommutative geometry. It is useful to divide the various proposals into propo

Roberto Giambo'

It is known that de Sitter spacetime can be seen as the solution of field equation for completely isotropic matter. In the present paper a new class of exact solutions in spherical symmetry is found and discussed, such that the energy--momentum tensor has two 2--dimensional distinct isotropic subspaces.

He Han, Zhao Zheng

Adopting thin film brick-wall model, we calculate the entropy of a nonuniformly rectilinearly accelerating non-stationary black hole expressed by Kinnersley metric. Because the black hole is accelerated, the event horizon is axisymmetric. The different points of horizon surface may have different temperature. We calculate the temperature and the entropy dens

Erik F. Tjong Kim Sang

We present memory-based learning approaches to shallow parsing and apply these to five tasks: base noun phrase identification, arbitrary base phrase recognition, clause detection, noun phrase parsing and full parsing. We use feature selection techniques and system combination methods for improving the performance of the memory-based learner. Our approach is

U. Welp, Z. L. Xiao, J. S. Jiang, V. K. Vlasko-Vlasov

Nb films containing extended arrays of holes with 45-nm diameter and 100-nm spacing have been fabricated using anodized aluminum oxide (AAO) as substrate. Pronounced matching effects in the magnetization and Little-Parks oscillations of the superconducting critical temperature have been observed in fields up to 9 kOe. Flux pinning in the patterned samples is

R. Dick

I propose to use Hamiltonians which contain two-dimensional and three-dimensional kinetic terms for the description of two-dimensional systems in physics. As a model system the evolution of three-dimensional wavefunctions in the presence of an infinitely thin layer is studied. The model predicts distance laws for correlation functions which interpolate betwe

Nathan W. Mueggenburg, Heinrich M. Jaeger, Sidney R. Nagel

We measure the local contact forces at both the top and bottom boundaries of three-dimensional face-centered-cubic and hexagonal-close-packed granular crystals in response to an external force applied to a small area at the top surface. Depending on the crystal structure, we find markedly different results which can be understood in terms of force balance co

Kevin E. Strecker, Guthrie B. Partridge, Andrew G. Truscott, Randall G. Hulet

Attraction between atoms in a Bose-Einstein-Condensate renders the condensate unstable to collapse. Confinement in an atom trap, however, can stabilize the condensate for a limited number of atoms, as was observed with 7Li, but beyond this number, the condensate collapses. Attractive condensates constrained to one-dimensional motion are predicted to form sta

Ramin Golestanian, Elie Raphael

The dynamics of the deformations of a moving contact line on a disordered substrate is formulated, taking into account both local and hydrodynamic dissipation mechanisms. It is shown that both the coating transition in contact lines receding at relatively high velocities, and the pinning transition for slowly moving contact lines, can be understood in a unif

R. A. Duine, H. T. C. Stoof

We show that a Bose-Einstein condensate emits atoms, if either the condensate wave function, or the scattering length of the atoms depends strongly on time. Moreover, the emission process is coherent and atoms can oscillate back and forth between the condensate and the excited states. Inspired by recent experimental results, we present results of simulations

A. Wallraff, A. Lukashenko, C. Coqui, T. Duty

We have developed a scheme for a high resolution measurement of the switching current distribution of a current biased Josephson tunnel junction using a timing technique. The measurement setup is implemented such that the digital control and read-out electronics are optically decoupled from the analog bias electronics attached to the sample. We have successf

Wei Zhang, Alexander O. Govorov, Sergio E. Ulloa

We consider a polaron model where molecular \emph{rotations} are important. Here, the usual hopping between neighboring sites is affected directly by the electron-phonon interaction via a {\em twist-dependent} hopping amplitude. This model may be of relevance for electronic transport in complex molecules and polymers with torsional degrees of freedom, such a

Hendrik Ulbricht, Gunnar Moos, Tobias Hertel

We present a study on the kinetics of oxygen adsorption and desorption from single-wall carbon nanotube (SWNT) and highly oriented pyrolytic graphite (HOPG) samples. Thermal desorption spectra for SWNT samples show a broad desorption feature peaked at 62 K which is shifted to significantly higher temperature than the low-coverage desorption feature on HOPG.

Takeru Suzuki, Hiroshi Imamura, Masahiko Hayashi, Hiromichi Ebisawa

We study orbital magnetism in a three-dimensional (3D) quantum dot with a parabolic confining potential. We calculate the free energy of the system as a function of the magnetic field and the temperature. By this, we show that the temperature-field plane can be classified into three regions in terms of the characteristic behavior of the magnetization: the La

M. R. Evans, Y. Kafri, E. Levine, D. Mukamel

An asymmetric exclusion process comprising positive particles, negative particles and vacancies is introduced. The model is defined on a ring and the dynamics does not conserve the number of particles. We solve the steady state exactly and show that it can exhibit a continuous phase transition in which the density of vacancies decreases to zero. The model ha

J. M. Benoit, B. Corraze, O. Chauvet

Low field and high field transport properties of carbon nanotubes/polymer composites are investigated for different tube fractions. Above the percolation threshold f_c=0.33%, transport is due to hopping of localized charge carriers with a localization length xi=10-30 nm. Coulomb interactions associated with a soft gap Delta_CG=2.5 meV are present at low temp

G. Tiana, R. A. Broglia

In a similar way in which the folding of single--domain proteins provide an important test in the study of self--organization, the folding of homodimers constitute a basic challenge in the quest for the mechanisms which are at the basis of biological recognition. Dimerization is studied by following the evolution of two identical 20--letter amino acid chains

Kestutis Staliunas, Stefano Longhi, German J. de Valcarcel

Temporal periodic modulation of the interatomic s-wave scattering length in Bose-Einstein condensates is shown to excite subharmonic patterns of atom density through a parametric resonance. The dominating wavelength of the spatial structures is shown to be primarily selected by the excitation frequency but also affected by the depth of the spatial modulation

Rusko Ruskov, Alexander N. Korotkov

We have studied theoretically the basic operation of a quantum feedback loop designed to maintain a desired phase of quantum coherent oscillations in a single solid-state qubit. The degree of oscillations synchronization with external harmonic signal is calculated as a function of feedback strength, taking into account available bandwidth and coupling to env

Jun-ichi Igarashi, Tatsuya Nagao

We calculate the resonant x-ray scattering (RXS) spectra near the Ce $L_{\rm III}$ absorption edge in CeB$_6$, on the basis of a microscopic model that the $4f$ states of Ce are atomic while the $5d$ states form an energy band with a reasonable density of states. In the initial state, we employ an effective Hamiltonian of Shiina {\it et al}. in the antiferro

W. Zheng, C. J. Hamer

The two-hole excitation spectrum of the t-J ladder at half-filling is studied using linked-cluster series expansion methods. A rich spectrum of bound states emerges, particularly at small $t/J$. Their dispersion relations and coherence lengths are computed, along with the threshold behaviour as the bound states merge into the continuum. A class of 4-hole bou

C. A. Ullrich, W. Kohn

This paper clarifies the topology of the mapping between v- and n-space in fermionic systems. Density manifolds corresponding to degeneracies g=1 and g>1 are shown to have the same mathematical measure: every density near a g-ensemble-v-representable (g-VR) n(r) is also g-VR (except ``boundary densities'' of lower measure). The role of symmetry and t

B. Noheda, L. Wu, Y. Zhu

TEM has shown that the strongly piezoelectric material Pb(Zr0.52Ti0.48)O3 separates into two phases at low temperatures. The majority phase is the monoclinic phase previously found by x-ray diffraction. The minority phase, with a nanoscale coherence length, is a slightly distorted variant of the first resulting from the anti-phase rotation of the oxygen octa

J. Silva-Valencia, E. Miranda, Raimundo R. dos Santos

We investigate Luttinger Liquid superlattices, a periodic structure composed of two kinds of one-dimensional systems of interacting electrons. We calculate several properties of the low-energy sector: the effective charge and spin velocities, the compressibility, various correlation functions, the Landauer conductance and the Drude weight. The low-energy pro

Julian H. Krolik

Although soft X-ray absorption features in AGN were discovered almost ten years ago, the nature and location of the gas creating them has remained controversial. However, by making use of the newly-available high-resolution spectra provided by XMM-Newton and Chandra, we should be able to make substantial advances. The first such spectra indicate that multipl

Hector G. Arce, Alyssa A. Goodman

We present a set of detailed molecular line maps of the region associated with the giant Herbig-Haro flow HH 315, from the young star PV Cephei, aimed at studying the outflow-cloud interaction. Our study clearly shows that the HH 315 flow is effecting the kinematics of its surrounding medium, and has been able to redistribute considerable amounts of the surr

Krzysztof Belczynski, Tomasz Bulik, Vassiliki Kalogera

Using the StarTrack population synthesis code we analyze the formation channels possibly available to double neutron star binaries and find that they can be richer than previously thought. We identify a group of short lived, tight binaries, which do not live long enough to escape their host galaxies, despite their large center-of-mass velocities. We present

Robert J. Klinger, John R. Dickel, Brian D. Fields, Douglas K. Milne

We present images of the supernova remnant N206 in the LMC, taken with ATCA at wavelengths of 3 and 6 cm. Based on our data and previously published flux densities, the spectral index of N206 is -0.20 +- 0.07. The 6-cm radio morphology shows a filled center. Most interesting is the discovery of a peculiar linear feature previously undetected at any wavelengt

Riccardo Giovanelli, Martha P. Haynes

We use the tapering effect of Halpha/[NII] rotation curves of spiral galaxies first noted by Goad & Roberts (1981) to investigate the internal extinction in disks. The scale length of exponential fits to the inner part of rotation curves depends strongly on the disk axial ratio. Preliminary modelling of the effect implies substantial opacity of the central p

Glen Petitpas, Christine Wilson

Double bars have been proposed as a means of transporting molecular gas past inner Lindblad resonances into the nuclear regions, where it can fuel active or starburst nuclei. Thus far, the existence of double bars has been determined predominantly through analysis of near infrared images, which can tell us little about the dynamics and inflow rates of these

D. Sauer, A. W. A. Pauldrach

Type Ia supernovae are an important tool for studying the expansion history of the universe. Advancing our yet incomplete understanding of the explosion scenario requires detailed and realistic numerical models in order to interpret and analyze the growing amount of observational data. Here we present first results of our new NLTE model calculations for the

M. Salaris, A. Weiss

We present homogeneous age determinations for a large sample of 55 Galactic globular clusters, which constitute about 30% of the total Galactic population. A study of their age distribution reveals that all clusters from the most metal poor ones up to intermediate metallicities are coeval, whereas at higher [Fe/H] an age spread exists, together with an age-m

P. Kaaret, J. J. M. in 't Zand, J. Heise, J. A. Tomsick

We report the discovery of millisecond oscillations in the X-ray emission from the X-ray transient SAX J1750.8-2900. Millisecond quasiperiodic oscillations (kHz QPOs) were present in the persistent emission with frequencies ranging from 543 Hz to 1017 Hz. Oscillations at a frequency of 600.75 Hz were present in the brightest X-ray burst observed. We derive a

B. Wolff, D. Koester, J. Liebert

We present a small data base of homogeneously derived photospheric element abundances of DZ white dwarfs and related objects. Our previous investigations are supplemented with the analysis of ultraviolet spectra for nine white dwarfs. Of particular interest is the detection of Lalpha absorption in van Maanen 2 and a determination of the effective temperature

C. Barraud, J. L. Atteia, J. F. Olive, J. P. Dezalay

The FREGATE gamma ray detector of HETE-2 is sensitive to photons between 6 and 400 keV. This sensitivity range, extended towards low energies, allows us to explore the emission of GRBs in hard X-rays. We fit the spectra of 23 GRBs with Band's spectral function in order to derive the distribution of their peak energies (E-peak). This distribution is then

Julien Malzac, Annalisa Celotti

We compute the hard X-ray spectra from a hot plasma pervaded by small cold dense clouds. The main cooling mechanism of the plasma is Compton cooling by the soft thermal emission from the clouds. We compute numerically the equilibrium temperature of the plasma together with the escaping spectrum. The spectrum depends mainly on the amount of cold clouds fillin

D. A. Smith, C. Akerlof, M. C. B. Ashley, D. Casperson

We report on the current operating status of the ROTSE-IIIa telescope, currently undergoing testing at Los Alamos National Laboratories in New Mexico. It will be shipped to Siding Spring Observatory, Australia, in first quarter 2002. ROTSE-IIIa has been in automated observing mode since early October, 2001, after completing several weeks of calibration and c

Alejandra Recio-Blanco, Giampaolo Piotto, Antonio Aparicio, Alvio Renzini

We present high resolution UVES+VLT spectroscopic observations of 56 stars in the extended horizontal branch (EHB) of the Galactic globular clusters NGC 1904, NGC 2808, NGC 6093, and NGC 7078. Our data reveal for the first time the presence in NGC 1904 of a sizable population of fast (vsini > 20 km/s) horizontal branch (HB) rotators, confined to the cool end

V. V. Usov

Creation of electron-positron pairs near the pulsar surface and the parameters of plasma in pulsar magnetospheres are discussed. It is argued that the pair creation process is nonstationary, and the pair plasma that flows out from the pulsar environment is strongly nonhomogeneous and gathers into separate clouds. Plasma instabilities in the outflowing plasma

N. W. Evans, S. A. Tabachnik

High resolution simulations are used to map out the detailed structure of two long-lived stable belts of asteroid orbits in the inner Solar system. The Vulcanoid belt extends from 0.09 to 0.20 astronomical units (au), though with a gaps at 0.15 and 0.18 au corresponding to de-stabilising mean motion resonances with Mercury and Venus. As collisional evolution

C. Ikuta, N. Arimoto, Authors ad infinitum

Star formation and chemical enrichment histories of the dwarf spheroidal galaxies (dSphs) Draco, Sextans, and Ursa Minor are investigated by means of chemical evolution models and a simulation code for colour-magnitude diagrams (CMDs). The CMD simulation code is designed to fully consider effects of the chemical evolution on stellar evolution and photometric

R. A. Windhorst, V. A. Taylor, R. A. Jansen, S. C. Odewahn

(Abbreviated) We present an imaging survey of 37 nearby galaxies observed with HST/WFPC2 in the mid-UV F300W filter and in F814W. 11 galaxies were also imaged in F255W. These galaxies were selected to be detectable with WFPC2 in one orbit, and cover a wide range of Hubble types and inclinations. The mid-UV spans the gap between our groundbased optical/NIR im

Joshua A. Faber, Philippe Grandclement, Frederic A. Rasio, Keisuke Taniguchi

Coalescing binary neutron stars (NS) are expected to be an important source of gravitational waves (GW) detectable by laser interferometers. We present here a simple method for determining the compactness ratio M/R of NS based on the observed deviation of the GW energy spectrum from point-mass behavior at the end of an inspiral event. Our method is based on

Ginestra Bianconi

We introduce a model for growing Cayley trees with thermal noise. The evolution of these hierarchical networks reduces to the Eden model and the Invasion Percolation model in the limit $T\to 0$, $T\to \infty$ respectively. We show that the distribution of the bond strengths (energies) is described by the Fermi statistics. We discuss the relation of the prese

R. E. Mennickent, G. Pietrzynski, W. Gieren, O. Szewczyk

Recently the OGLE experiment has provided accurate light curves and colours for about 2 millions stars in the Small Magellanic Cloud. We have examined this database for its content of Be stars, applying some selection criteria, and we have found a sample of $\sim$ 1000 candidates. Some of these stars show beautiful light curves with amazing variations never

Gabriel Carlo, Eduardo Vergini, Pablo Lustemberg

In the context of the semiclassical theory of short periodic orbits, scar functions play a crucial role. These wavefunctions live in the neighbourhood of the trajectories, resembling the hyperbolic structure of the phase space in their immediate vicinity. This property makes them extremely suitable for investigating chaotic eigenfunctions. On the other hand,

Vijay Balasubramanian, Min-xin Huang, Thomas S. Levi, Asad Naqvi

Exploiting insights on strings moving in pp-wave backgrounds, we show how open strings emerge from N = 4 SU(M) Yang-Mills theory as fluctuations around certain states carrying R-charge of order M. These states are dual to spherical D3-branes of AdS_5 x S^5 and we reproduce the spectrum of small fluctuations of these states from Yang Mills theory. When G such

David Tong

The equivalence of NS5-branes and ALF spaces under T-duality is well known. However, a naive application of T-duality transforms the ALF space into a smeared NS5-brane, de-localized on the dual, transverse, circle. In this paper we re-examine this duality, starting from a two-dimensional N=(4,4) gauged linear sigma model describing Taub-NUT space. After dual

B. I. Shklovskii

A mechanism of $1/f$ noise due to traps formed by impurities which have no neighbors with close energies in their vicinity is studied. Such traps slowly exchange electrons with the rest of conducting media. The concentration of traps and proportional to it $1/f$ noise exponentially grow with decreasing temperature in the variable range hopping regime. This t

Nicole F. Bell, R. F. Sawyer, Raymond R. Volkas, Yvonne Y. Y. Wong

We discuss some systematic methods for implementing state manipulations in systems formally similar to chains of a few spins with nearest-neighbor interactions, arranged such that there are strong and weak scales of coupling links. States are permuted by means of bias potentials applied to a few selected sites. This generic structure is then related to an at

Philippe Brax, Adam Falkowski, Zygmunt Lalak, Stefan Pokorski

We consider non-supersymmetric quiver theories obtained by orbifolding the N=4 supersymmetric U(K) gauge theory by a discrete Z_Γgroup embedded in the SU(4) R-symmetry group. We explicitly find that in such theories there are no one-loop quadratic divergences in the effective potential. Moreover, when the gauge group U(n)^Γof the quiver theory is spontaneous

Joydeep Bagchi, Torsten A. Ensslin, Francesco Miniati, C. S. Stalin

We report the discovery of large-scale diffuse radio emission from what appears to be a large-scale filamentary network of galaxies in the region of cluster ZwCl 2341.1+0000, and stretching over an area of at least $6 h^{-1}_{50}$ Mpc in diameter. Multicolour CCD observations yield photometric redshifts indicating that a significant fraction of the optical g

A. Romanelli, A. C. Sicardi Schifino, G. Abal, R. Siri

The separation of the Schrödinger equation into a Markovian and an interference term provides a new insight in the quantum dynamics of classically chaotic systems. The competition between these two terms determines the localized or diffusive character of the dynamics. In the case of the Kicked Rotor, we show how the constrained maximization of the entropy im

Hongsu Kim

Using an exact supergravity solution representing the Dp-\bar{Dp} system, it is demonstrated that one can construct a supergravity analogue of the tachyon potential. Remarkably, the (regularized) minimum value of the potential turns out to be V(T_{0})=-2m with m denoting the ADM mass of a single Dp-brane. This result, in a sense, appears to confirm that Sen&

Parampreet Singh, Naresh Dadhich

The most remarkable and interesting feature of brane world scenario is the use of bulk's curvature to localize gravity on the brane, albeit with fine tuning of the brane and bulk parameters. For FRW expanding universe on the brane, it is a moving hypersurface in Schwarzschild anti de Sitter bulk spacetime. We show that zero mass gravitons have bound stat

S. Elitzur, A. Giveon, D. Kutasov, E. Rabinovici

We study a quotient Conformal Field Theory, which describes a 3+1 dimensional cosmological spacetime. Part of this spacetime is the Nappi-Witten (NW) universe, which starts at a ``big bang'' singularity, expands and then contracts to a ``big crunch'' singularity at a finite time. The gauged WZW model contains a number of copies of the NW spac

Kurt Broderix, Martin Weigt, Annette Zippelius

We consider the gelation of particles which are permanently connected by random crosslinks, drawn from an ensemble of finite-dimensional continuum percolation. To average over the randomness, we apply the replica trick, and interpret the replicated and crosslink-averaged model as an effective molecular fluid. A Mayer-cluster expansion for moments of the loca

S. Colson, M. Konczykowski, M. B. Gaifullin, Y. Matsuda

Vortex thermal fluctuations in heavily underdoped Bi2Sr2CaCu2O8+d (Tc=69.4 K) are studied using Josephson plasma resonance (JPR). From the data in zero magnetic field, we obtain the penetration depth along the c-axis, lambda_{L,c}(0) = 229 micrometers and the anisotropy ratio gamma(0) = 600. The low plasma frequency allows us to study phase correlations over

R. Foot, R. R. Volkas

SNO's neutral current measurement has added a new piece to the emerging neutrino physics puzzle. Putting together the presently available experimental information, an essentially unique picture emerges: The solar neutrino anomaly is explained by nu_e --> nu_tau oscillations, the atmospheric neutrino anomaly is explained by nu_{mu} --> nu_s and the LSND d

K. Malarz, S. Kaczanowska, K. Kulakowski

In the thermodynamic limit, a probabilistic cellular automaton can be approximated by a deterministic nonlinear map. Here we construct such a map for the forest fire problem. The construction is based on the results of the Monte Carlo simulation, performed on a square lattice of million cells. The results of the calculation are analyzed by means of the Hoshe

N. K. Spyrou, N. Stergioulas

Using a highly accurate numerical code, we study the spin down of rotating relativistic stars, undergoing a quark deconfinement phase transition. Such phase transitions have been suggested to yield an observable signal in the braking index of spinning-down pulsars, which is based on a ``backbending'' behaviour of the moment of inertia. We focus on a

Woong-Seob Jeong, Soojong Pak, Hyung Mok Lee, Takao Nakagawa

We describe the observing simulation software FISVI (FIS Virtual Instrument), which was developed for the Far-Infrared Surveyor (FIS) that will be on the Japanese infrared astronomy mission ASTRO-F. The FISVI has two purposes: one is to check the specifications and performances of the ASTRO-F/FIS as a whole; the other is to prepare input data sets for the da

M. Fukugita, M. Kawasaki

We discuss the implication of the observation of supernova relic neutrinos on the study of the star formation rate (SFR) in galaxies. The limit recently obtained at Super-Kamiokande (SK) is already marginally significant: The SFR we derived $ψ(t_0)<0.040M_{\odot}$yr$^{-1}$Mpc$^{-3}$(at a 90% CL) is about twice the SFR estimated from radio observations, and f

C. L. Yang, J. Zhang, R. R. Du, J. A. Simmons

Magnetotransport in a laterally confined two-dimensional electron gas (2DEG) can exhibit modified scattering channels owing to a tilted Hall potential. Transitions of electrons between Landau levels with shifted guiding centers can be accomplished through a Zener tunneling mechanism, and make a significant contribution to the magnetoresistance. A remarkable

A. Zh. Muradyan, G. A. Muradyan

In the paper are considered stationary (Bloch) states of a particle, in the field of periodic biparabolic type potential. It is shown that while the particle&#39;s energy decreases in limits of a single energy band, the probability of the particle to be in barrier-type region of periodic potential increases, in contrary to the expected decreasing. This &#39;

Kevin H. Knuth

In celebration of the work of Richard Threlkeld Cox, we explore inductive logic and its role in science touching on both experimental design and analysis of experimental results. In this exploration we demonstrate that the duality between the logic of assertions and the logic of questions has important consequences. We discuss the conjecture that the relevan

M. W. McCall, A. Lakhtakia, W. S. Weiglhofer

We study electromagnetic wave propagation in mediums in which the effective relative permittivity and the effective relative permeability are allowed to take any value in the upper half of the complex plane. A general condition is derived for the phase velocity to be oppositely directed to the power flow. That extends the recently studied case of propagation

C. Conti, S. Trillo, P. Di Trapani, G. Valiulis

Nonlinear optical media that are normally dispersive, support a new type of localized (nondiffractive and nondispersive) wavepackets that are X-shaped in space and time and have slower than exponential decay. High-intensity X-waves, unlike linear ones, can be formed spontaneously through a trigger mechanism of conical emission, thus playing an important role

W. Zuo, U. Lombardo, C. W. Shen

The equations of state of spin-polarized nuclear matter and pure neutron matter are studied in the framework of the Brueckner-Hartree-Fock theory including a three-body force. The energy per nucleon $E_A(δ)$ calculated in the full range of spin polarization $δ = \frac{ρ_{\uparrow}-ρ_{\downarrow}}ρ$ for symmetric nuclear matter and pure neutron matter fulfill

Felipe Barra, Thomas Gilbert

We study the algebraic decay of the survival probability in open hierarchical graphs. We present a model of a persistent random walk on a hierarchical graph and study the spectral properties of the Frobenius-Perron operator. Using a perturbative scheme, we derive the exponent of the classical algebraic decay in terms of two parameters of the model. One param

Dirk Blömker, Martin Hairer

We consider a class of stochastic partial differential equations arising as a model for amorphous thin film growth. Using a spectral Galerkin method, we verify the existence of stationary mild solutions, although the specific nature of the nonlinearity prevents us from showing the uniqueness of the solutions as well as their boundedness (in time).

R. R. Gadyl&#39;shin

We adduce the necessary and sufficient condition for arising of eigenvalues of Shrodinger operator in axis under small local perturbations. In the case of eigenvalues arising we construct their asymptotics.

T. A. Larsson

I argue that string theory can not be a serious candidate for the Theory of Everything, not because it lacks experimental support, but because of its algebraic shallowness. I describe two classes of algebraic structures which are deeper and more general than anything seen in string theory: The multi-dimensional Virasoro algebras, i.e. the abelian but non-cen

Bohui Chen

A smooth compactification of Donaldson moduli spaces is given. As an application, we use this new space to study the wall-crossing formula and prove the Kotschick-Morgan conjecture.

Denis Auroux

We describe a simplification of Donaldson&#39;s arguments for the construction of symplectic hypersurfaces or Lefschetz pencils that makes it possible to avoid any reference to Yomdin&#39;s work on the complexity of real algebraic sets.

Denis Auroux

Using the recent results of Siebert and Tian about the holomorphicity of genus 2 Lefschetz fibrations with irreducible singular fibers, we show that any genus 2 Lefschetz fibration becomes holomorphic after fiber sum with a holomorphic fibration.

Michael Nakamaye

Suppose D is an effective divisor on a smooth projective algebraic variety X. For each point x of X we associate a numberical invariant called the moving Seshadri constant of D at x which is a numerical measure of positivity of the divisor D at x. We determine the base locus of a large multiple of D by studying these moving Seshadri constants-- the drawback

Mirko Primc

For an untwisted affine Kac-Moody Lie algebra $\tilde{\mathfrak g}$, and a given positive integer level $k$, vertex operators $x(z)=\sum x(n)z^{-n-1}$, $x\in\mathfrak g$, generate a vertex operator algebra $V$. For the maximal root $θ$ and a root vector $x_θ$ of the corresponding finite-dimensional $\mathfrak g$, the field $x_θ(z)^{k+1}$ generates all annihi

David E Evans

We review the framework subfactors provide for understanding modular invariants. We discuss the structure of a generalized Longo-Rehren subfactor and the relationship between the coupling matrices of such subfactors, modular invariance and local extensions. We relate results of Kostant, in the context of the McKay correspondence for finite subgroups of SU(2)

Cyril Grunspan

This text gives some results about quantum torsors. Our starting point is an old reformulation of torsors recalled recently by Kontsevich. We propose an unification of the definitions of torsors in algebraic geometry and in Poisson geometry. Any quantum torsor is equipped with two comodule-algebra structures over Hopf algebras and these structures commute wi

Tom Leinster

We define the phrase `category enriched in an fc-multicategory&#39; and explore some examples. An fc-multicategory is a very general kind of 2-dimensional structure, special cases of which are double categories, bicategories, monoidal categories and ordinary multicategories. Enrichment in an fc-multicategory extends the (more or less well-known) theories of

David E Evans

Modular invariants satisfy remarkable fusion rules. Let $Z$ be a modular invariant associated to a braided subfactor $N\subset M$. The decomposition of the non-normalized modular invariants $Z Z^{*}$ and $Z^{*}Z$ into sums of normalized modular invariants is related to the decomposition of the full induced $M-M$ system of sectors.

Akio Arimoto

We give an easy proof to show that every complex normal Toeplitz matrix is classified as either of type I or of type II. Instead of difference equations on elements in the matrix used in past studies, polynomial equations with coefficients of elements are used. In a similar fashion, we show that a real normal Toeplitz matrix must be one of four types: symmet

Christopher Deninger

We discuss analogies between the etale site of arithmetic schemes and the algebraic topology of dynamical systems. The emphasis is on Lefschetz numbers. We also discuss similarities between infinite primes in arithmetic and fixed points of dynamical systems.

Soon-Tae Hong, Jaedong Choi, Young-Jai Park

We study a multiply warped products manifold associated with the Reissner-Nordstrom metric to investigate the physical properties inside the black hole event horizons. It is shown that, different from the uncharged Schwarzschild metric, the Ricci curvature components inside the Reissner-Nordstrom black hole horizons are nonvanishing, while the Einstein scala

Alexander Berkovich, Frank G. Garvan

We utilize Dyson&#39;s concept of the adjoint of a partition to derive an infinite family of new polynomial analogues of Euler&#39;s Pentagonal Number Theorem. We streamline Dyson&#39;s bijection relating partitions with crank <= k and those with k in the Rank-Set of partitions. Also, we extend Dyson&#39;s adjoint of a partition to MacMahon&#39;s ``modular&#

Paul D. Mitchener

We define KK-theory spectra associated to C*-categories and look at certain instances of the Kasparov product at this level. This machinery is used to give a description of the analytic assembly map as a natural map of spectra.

S. Coriasco, E. Schrohe, J. Seiler

We study an elliptic differential operator A on a manifold with conic points. Assuming A to be defined on the smooth functions supported away from the singularities, we first address the question of possible closed extensions of A to L^p Sobolev spaces and then explain how additional ellipticity conditions ensure maximal regularity for the operator A. Invest