August 2004 arXiv papers — page 18

Andre Gsponer, Jean-Pierre Hurni

Lanczos's idea of classical electrodynamics as a biquaternionic field theory in which point singularities are interpreted as electrons is reevaluated. Using covariant quaternionic integration techniques developed by Paul Weiss in 1941, we show that the Lagrangian suggested by Lanczos in his thesis of 1919 is equivalent to the standard Lagrangian of class

Frank Calegari

Following Apery's proof of the irrationality of zeta(3), Beukers found an elegant reinterpretation of Apery's arguments using modular forms. We show how Beukers arguments can be adapted to a p-adic setting. In this context, certain functional equations arising from Eichler integrals are replaced by the notion of overconvergent p-adic modular forms, a

David Fisher, Gregory Margulis

Let $J$ be a semisimple Lie group with all simple factors of real rank at least two. Let $Γ<J$ be a lattice. We prove a very general local rigidity result about actions of $J$ or $Γ$. This shows that almost all so-called &#34;standard actions&#34; are locally rigid. As a special case, we see that any action of $Γ$ by toral automorphisms is locally rigid. Mor

Karin Erdmann, Manfred Schocker

Let $V$ be an $r$-dimensional vector space over an infinite field $F$ of prime characteristic $p$, and let $L_n(V)$ denote the $n$-th homogeneous component of the free Lie algebra on $V$. We study the structure of $L_n(V)$ as a module for the general linear group $GL_r(F)$ when $n=pk$ and $k$ is not divisible by $p$ and where $n \geq r$. Our main result is a

Alexander G. Ramm, Semion Gutman

In many Direct and Inverse Scattering problems one has to use a parameter-fitting procedure, because analytical inversion procedures are often not available. In this paper a variety of such methods is presented with a discussion of theoretical and computational issues. The problem of finding small subsurface inclusions from surface scattering data is solved

Alfons Van Daele

Consider a C*-algebra $A$ with a comultiplication $Δ$. This pair is usually thought of as locally compact quantum semi-group. When these notes were written, in 1993, it was not at all clear what the extra assumptions on the comultiplication should be for this pair to be a &#39;locally compact quantum group&#39;. This only became clear in 1999 thanks to the w

Pablo Shmerkin

We study families of possibly overlapping self-affine sets. Our main example is a family that can be considered the self-affine version of Bernoulli convolutions and was studied, in the non-overlapping case, by F.Przytycki and M.Urbanski. We extend their results to the overlapping region and also consider some extensions and generalizations.

Eric Bedford, Kyounghee Kim

Let $f$ be a birational map of ${\bf C}^d$, and consider the degree complexity, or asymptotic degree growth rate $δ(f)=\lim_{n\to\infty}({\rm deg}(f^n))^{1/n}$. We introduce a family of elementary maps, which have the form $f=L\circ J$, where $L$ is (invertible) linear, and $J(x_1,...,x_d)=(x_1^{-1},...,x_d^{-1})$. We develop a method of regularization and s

Aidan Sims

We produce a complete descrption of the lattice of gauge-invariant ideals in $C^*(Λ)$ for a finitely aligned $k$-graph $Λ$. We provide a condition on $Λ$ under which every ideal is gauge-invariant. We give conditions on $Λ$ under which $C^*(Λ)$ satisfies the hypotheses of the Kirchberg-Phillips classification theorem.

Masatoshi Enomoto, Yasuo Watatani

The relative position of one subfactor of a factor has been proved quite rich since the work of Jones. We shall show that the theory of relative position of several subspaces of a separable infinite-dimensional Hilbert space is also rich. In finite-dimensonal case, Gelfand and Ponomarev gave a complete classification of indecomposable systems of four subspac

David Fisher, G. A. Margulis

Let $Γ$ be a discrete group with property $(T)$ of Kazhdan. We prove that any Riemannian isometric action of $Γ$ on a compact manifold $X$ is locally rigid. We also prove a more general foliated version of this result. The foliated result is used in our proof of local rigidity for standard actions of higher rank semisimple Lie groups and their lattices in \c

I. V. Burskii

In this paper we propose some approaches for finding of pointwise estimates of a solution of the Dirichlet boundary value problem $-Δu \pm |u|^{q-1} u = 0 $, $|u|=k$ when $|x|=d<1$ and $|u|=0$ when $|x|=1$ where $x\in Ω= \{x| d<|x|<1\}$. Along with these we consider the same boundary conditions for the Laplace equation and get appropriate estimates for this

J. Luis Miramontes

The T-duality symmetries of a family of two-dimensional massive integrable field theories defined in terms of asymmetric gauged Wess-Zumino-Novikov-Witten actions modified by a potential are investigated. These theories are examples of massive non-linear sigma models and, in general, T-duality relates two different dual sigma models perturbed by the same pot

Jialun Ping, Di Qing, Fan Wang, T. Goldman

The pentaquark state recently discovered has been studied with three quark models which either fit the nucleon spin structure or the $NN$ scattering. A minimum $Θ^+$ mass of 1620 MeV is obtained both for the ${1/2}^\pm$ state. The mixing of various color structure configurations, which would reduce the mass of the penta-quark state, should be taking into acc

L. M. Sehgal

Rare decays of K mesons are reviewed from the perspective of testing the ``ones&#39;&#39; and ``zeros&#39;&#39; of the standard model. Decays K^+ -> pi^+ nu anti-nu and K_L -> pi^0 nu anti-nu probe the one-loop effective Hamiltonian for s -> d nu anti-nu, and can constrain the rho, eta coordinates of the unitarity triangle. Decays such as K_L -> pi^0 l^+ l^-

A. A. Akhundov, H. H. Alharbi, H. A. Alhendi

A numerical analysis of QED radiative corrections for elastic e(mu)p cattering in hadronic variables at energies of the current experiment at JLab is performed. The explicit formulas from the review of Akhundov et al. resulting from the integration over the phase space of leptonic variables plus photon are used to obtain the values of the cross sections and

Chun-Gui Duan, Shu-Wen Cui, Zhan-Yuan Yan, Guang-Lie Li

The energy loss effect in nuclear matter is another nuclear effect apart from the nuclear effects on the parton distribution as in deep inelastic scattering process. The quark energy loss can be measured best by the nuclear dependence of the high energy nuclear Drell-Yan process. By means of three kinds of quark energy loss parameterizations given in literat

Guenter Sigl

These are extended notes of a series of lectures given at the XIth Brazilian School of Cosmology and Gravitation. They provide a selection of topics at the intersection of particle and astrophysics. The first part gives a short introduction to the theory of electroweak interactions, with specific emphasize on neutrinos. In the second part we apply this frame

UKQCD Collaboration, C. McNeile, C. Michael, Gavin Thompson

We compute the b quark mass from dynamical lattice QCD with clover quarks. The calculation is done at a fixed lattice spacing with sea quark masses as low as half the strange quark mass. Our final result is m_b(m_b} = 4.25(2)(11) GeV, where the first error is statistical and the last error is the systematic uncertainty.

Joe Christensen, Walter Wilcox, Frank X. Lee, Leming Zhou

By simulating a uniform electric field on a lattice and measuring the change in the rest mass, we calculate the electric polarizability of neutral mesons and baryons using the methods of quenched lattice QCD. Specifically, we measure the electric polarizability coefficient from the quadratic response to the electric field for 10 particles: the vector mesons

Jeff Greensite, Stefan Olejnik, Daniel Zwanziger

We review the confinement scenario in Coulomb gauge. We show that when thin center vortex configurations are gauge transformed to Coulomb gauge, they lie on the common boundary of the fundamental modular region and the Gribov region. This unifies elements of the Gribov confinement scenario in Coulomb gauge and the center-vortex confinement scenario. We repor

The BABAR Collaboration, B. Aubert

The process e+e- --> pi+ pi- pi0 gamma has been studied at a center-of-mass energy near the Y(4S) resonance using a 89.3 fb-1 data sample collected with the BaBar detector at the PEP-II collider. From the measured 3pi mass spectrum we have obtained the products of branching fractions for the omega and phi mesons, B(omega --> e+e-)B(omega --> 3pi)=(6.70 +/- 0

K. Y. Gao, CLEO Collaboration

Based on a data sample of 60 pb-1 collected at the psi(3770) resonance with the CLEO-c detector at CESR, we present improved measurements of absolute branching fractions for exclusive D0 semileptonic decays into K- e+ nu, pi- e+ nu and K*- e+ nu; and the first observation and absolute branching fraction measurement of D0 to rho- e+ nu.

B. Aubert, BaBar Collaboration

We present preliminary measurements of the CP asymmetry parameters and CP content in B0-->K+K-Ks decays, with phiKs events excluded. In a sample of 227M BB pairs collected by the BABAR detector at the PEPII B-Factory at SLAC, we find the CP parameters to be S = -0.42 +/- 0.17 +/- 0.04 and C = 0.10 +/- 0.14 +/- 0.06, where the first error is statistical and t

B. Aubert, The BaBar Collaboration

We study the inclusive electron spectrum of B->X_u e nu decays near the kinematic limit for B->X_c e nu transitions using a sample of 88 million Upsilon(4S) decays recorded by the BABAR detector at the PEP II e+e- storage rings. For the electron momentum interval of 2.0 - 2.6 GeV/c the partial branching fraction is measured to be DeltaB(B->X_u e nu) = (0.480

Alexis A. Aguilar-Arevalo

MiniBooNE is an experiment designed to provide a definitive test for the numubar to nuebar oscillations signal seen by LSND. Here, a brief summary of the MiniBooNE goals and strategies is presented, as well as some highlights of its current status.

The BABAR Collaboration, B. Aubert

We present a preliminary measurement of the time-dependent CP asymmetry for the neutral $B$-meson decay $B^0\toϕK^0$. We use a sample of approximately 227 million $B$-meson pairs recorded at the $Υ(4S)$ resonance with the BaBar detector at the PeP-II $B$-meson Factory at SLAC. We reconstruct the $CP$ eigenstates $ϕK^0_S$ and $ϕK^0_L$ where $ϕ\to K^+K^-$, $K^

D. Besson, CLEO Collaboration

In 60 pb-1 of data taken on the psi(3770) resonance with the CLEO-c detector, we find 8 D+ to mu+ nu event candidates that are mostly signal, containing only 1 estimated background. Using this statistically compelling sample, we measure preliminary values of B(D+ to mu+ nu) = (3.5 +- 1.4 +- 0.6)*10^{-4}, and determine f_{D+} =(201+- 41+- 17) MeV.

D. M. Asner, CLEO Collaboration

Using data collected by the CLEO III detector at CESR, we started a series of investigations on the Upsilon(5S) resonance decay properties. The data sample used for this analysis consists of 0.42 fb-1 of data taken on the Upsilon(5S) resonance, 6.34 fb-1 of data collected on the Upsilon(4S) and 2.32 fb-1 of data taken in the continuum below the Upsilon(4S).

The BABAR Collaboration, B. Aubert

The properties of the $\DsTT$ and $\DsFE$ mesons are studied using 125 ${\rm fb}^{-1}$ of $e^+e^- \to c \bar{c}$ data collected by the BaBar experiment. Preliminary mass estimates of $[2318.9\pm 0.3 ({\rm stat.}) \pm 0.9 ({\rm syst.})]$ \mevcc and $[2459.4 \pm 0.3 ({\rm stat.}) \pm 1.0 ({\rm syst.})]$ \mevcc are obtained. Searches are performed for the decay

B. Aubert, BABAR Collaboration

Based on an 87-fb$^{-1}$ dataset collected by the Babar detector at the PEP-II asymmetric-energy $B$-Factory, a search for $D^{0}$--$\bar{D}^{0}$ mixing has been made using the semileptonic decay modes $D^{*+} \to π^{+} D^{0}, D^{0} \to K^{(*)}eν$ (+c.c.). The use of these modes allows unambiguous flavor tagging and a combined fit of the $D^{0}$ decay time a

The BABAR Collaboration, B. Aubert

We report a preliminary measurement of the branching fraction for the decay $B^0 \to K^0_sK^0_sK^0_s ,$ where the $K^0_s$ mesons are reconstructed through the decay $K^0_s\toπ^+ π^- .$ The measurement was performed on a sample of $211\times 10^6$ $B\bar{B}$ pairs collected by the BABAR detector running on the $Υ(4S)$ resonance at the PEP-II storage ring. The

Rodolfo Gambini, Rafael Porto, Jorge Pullin

We have recently argued that if one introduces a relational time in quantum mechanics and quantum gravity, the resulting quantum theory is such that pure states evolve into mixed states. The rate at which states decohere depends on the energy of the states. There is therefore the question of how this can be reconciled with Galilean invariance. More generally

L. Richterek, J. Horsky

By means of Ernst complex potential formalism it is shown, that previously studied static axisymmetric Einstein-Maxwell fields obtained though the application of the Horsky-Mitskievitch generating conjecture represent a combination of Kinnersley&#39;s transformations [W. Kinnersley: J. Math. Phys. 14 (1973) 651]. New theoretical background for the conjecture

G. Y. Chee

A self-dual and anti-self-dual decomposition of the teleparallel gravity is carried out and the self-dual Lagrangian of the teleparallel gravity which is equivalent to the Ashtekar Lagrangian in vacuum is obtained. Its Hamiltonian formulation and the constraint analysis are developed. Starting from Witten&#39;s equation Nester&#39;s gauge condition is derive

G. Y. Chee, Yongxin Guo

In order to discuss the well-posed initial value formulation of the teleparallel gravity and apply it to numerical relativity a symmetric hyperbolic system in the self-dual teleparallel gravity which is equivalent to the Ashtekar formulation is posed. This system is different from the ones in other works by that the reality condition of the spatial metric is

Elizabeth Winstanley

We discuss the existence, stability and classical thermodynamics of four-dimensional, spherically symmetric black hole solutions of the Einstein equations with a conformally coupled scalar field. We review the solutions existing in the literature with zero, positive and negative cosmological constant. We also outline new results on the thermodynamics of thes

G. David Forney, Mitchell D. Trott

Fundamental results concerning the dynamics of abelian group codes (behaviors) and their duals are developed. Duals of sequence spaces over locally compact abelian groups may be defined via Pontryagin duality; dual group codes are orthogonal subgroups of dual sequence spaces. The dual of a complete code or system is finite, and the dual of a Laurent code or

R. G. Melko, D. J. Scalapino

We present quantum Monte Carlo simulation results on a quantum S=1/2 XY model with ring exchange (the J-K model) on a three-dimensional simple cubic lattice. We first characterize the ground state properties of the pure XY model, obtaining estimations for the energy, spin stiffness and spin susceptibility at T=0 in the superfluid phase. With the ring exchang

Matthias Troyer, Uwe-Jens Wiese

Quantum Monte Carlo simulations, while being efficient for bosons, suffer from the &#34;negative sign problem&#39;&#39; when applied to fermions - causing an exponential increase of the computing time with the number of particles. A polynomial time solution to the sign problem is highly desired since it would provide an unbiased and numerically exact method

Clifford M. Krowne

It has been discovered that heterostructure bicrystal arrangements lead to field asymmetry in guided wave structures. Here a study is conducted over a range of nominal permittivity values to see if the effect is present in widely varying dielectric materials. Marked shifts of the field distribution occurs in some cases, and this can be the basis of an all el

C. A. Utreras-Díaz, J. C. Flores, A. Pérez-Ponce

The open electron resonator, described by Duncan et.al, is a mesoscopic device that has attracted considerable attention due to its remarkable behaviour (conductance oscillations), which has been explained by detailed theories based on the behaviour of electrons at the top of the Fermi sea. In this work, we study the resonator using the simple quantum quantu

D. I. Schuster, A. Wallraff, A. Blais, L. Frunzio

We have spectroscopically measured the energy level separation of a superconducting charge qubit coupled non-resonantly to a single mode of the electromagnetic field of a superconducting on-chip resonator. The strong coupling leads to large shifts in the energy levels of both the qubit and the resonator in this circuit quantum electrodynamics system. The dis

Nicolas Laflorencie, Didier Poilblanc

Low dimensional spin-1/2 systems with antiferromagnetic interactions display very innovative features, driven by strong quantum fluctuations. In particular, geometrical effects or competing magnetic interactions can give rise to the formation of a spin gap between the singlet ground state and the first excited triplet state. In this chapter, we focus on the

D. S. Saraga, B. L. Altshuler, Daniel Loss, R. M. Westervelt

We calculate the Coulomb scattering amplitude for two electrons injected with opposite momenta in an interacting 2DEG. We include the effect of the Fermi liquid background by solving the 2D Bethe-Salpeter equation for the two-particle Green function vertex, in the ladder and random phase approximations. This result is used to discuss the feasibility of produ

S. Das Sarma, E. H. Hwang

Motivated by recent experimental results reporting anomalous drag resistance behavior in dilute bilayer two-dimensional (2D) hole systems in the presence of a magnetic field parallel to the 2D plane, we have carried out a many-body Fermi liquid theory calculation of bilayer magnetodrag comparing it to the corresponding single layer magnetoresistance. In qual

M. N. Iliev, B. Lorenz, A. P. Litvinchuk, Y. -Q. Wang

Orthorhombic Y$_{1-x}$Ca$_x$MnO$_3$ ($0 \leq x \leq 0.5$) was prepared under high pressure and the variations with $x$ of its structural, magnetic, electrical properties and the polarized Raman spectra were investigated. The lattice parameters change systematically with $x$. Although there are strong indications for increasing disorder above $x = 0.20$, the

Serge Galam, Krzysztof Malarz

We study how to restore site percolation on a damaged square lattice with nearest neighbor (N$^2$) interactions. Two strategies are suggested for a density $x$ of destroyed sites by a random attack at $p_c$. In the first one, a density $y$ of new sites are created with longer range interactions, either next nearest neighbor (N$^3$) or next next nearest neigh

Hokky Situngkir, Yohanes Surya

The paper reports the construction of artificial stock market that emerges the similar statistical facts with real data in Indonesian stock market. We use the individual but dominant data, i.e.: PT TELKOM in hourly interval. The artificial stock market shows standard statistical facts, e.g.: volatility clustering, the excess kurtosis of the distribution of r

G. Ka&#34;lbermann, R. Wallach

We solve numerically the nonlinear differential equation for the Hele-Shaw, Saffman-Taylor problem derived in the preceding work. Stationary solutions with no free phenomenological parameters are found to fit the measured patterns. The calculated finger half-widths as a function of the physical parameters of the cell, compare satisfactorily with experiment.

G. Ka&#34;lbermann

We develop a stream function approach for the horizontal Hele-Shaw, Saffman-Taylor finger. The model yields a nonlinear time-dependent differential equation. The finger widths derived from the equation are $1>λ>\frac{1}{\sqrt{5}}$, in units of half the width of the Hele-Shaw cell, in accordance with observation. The equation contains the correct dispersion r

Balázs Dóra, Kazumi Maki, Attila Virosztek, András Ványolos

Very recently large Nernst effect and Seebeck effect were observed above the superconducting transition temperature 2.3K in a heavy fermion superconductor CeCoIn_5. We shall interpret this large Nernst effect in terms of unconventional density wave (UDW), which appears around T=18K. Also the temperature dependence of the Seebeck coefficient below T=18K is de

A. Amato, M. J. Graf, A. de Visser, H. Amitsuka

The behavior of the so-called weak moment antiferromagnetic states, observed in the heavy-fermion superconductors UPt$_3$ and URu$_2$Si$_2$, is discussed in view of recent $μ$SR results obtained as function of control parameters like chemical substitution and external pressure. In UPt$_3$, the Pd substitution for Pt reveals the dynamical character of the wea

I. E. Dzyaloshinskii, E. I. Kats

For the first time we present analytical results for the contribution of electromagnetic fluctuations into thermodynamic properties of modulated systems, like cholesteric or smectic liquid crystalline films. In the case of small dielectric anisotropy we have derived explicit analytical expressions for the chemical potential of such systems. Two limiting case

C. Ates, Ch. Moseley, K. Ziegler

For a hard-core Bose gas on a one-dimensional lattice we find characteristic oscillations in the density-density correlation function. Their wavelength diverges as the system undergoes a continuous transition from an incommensurate to a Mott insulating phase. The associated static structure factor vanishes as the Mott insulating phase is approached. The qual

V. A. Benderskii, E. V. Vetoshkin, E. I. Kats

We examine one overlooked in previous investigations aspect of well - known Landau - Zener (LZ) problem, namely, the behavior in the intermediate, i.e. close to a crossing point, energy region, when all four LZ states are coupled and should be taken into account. We calculate the 4 x 4 connection matrix in this intermediate energy region, possessing the same

V. P. S. Awana, M. A. Ansari, Anurag Gupta, R. B. Saxena

Samples of Y0.4Pr0.6Ba2-xSrxCu3O7 have been synthesized by a solid- state reaction route. The samples with x = 0.60 crystallize in an orthorhombic structure (with orthorhombic distortion decreasing with increasing x), while the samples with x=0.80 and 1.0 crystallize in a pseudo tetragonal structure. Resistance (R) measurements as a function of temperature (

Devaraj van der Meer, Peter Reimann

When smooth granular material is fluidized by vertically shaking a container, we find that the temperature in the direction of energy input always exceeds the temperature in the other directions. An analytical model is presented which shows how the anisotropy can be traced back to the inelasticity of the interparticle collisions and the collisions with the w

S. J. U. Higdon, D. Devost, J. L. Higdon, B. R. Brandl

SMART is a software package written in IDL to reduce and analyze Spitzer data from all four modules of the Infrared Spectrograph, including the peak-up arrays. The software is designed to make full use of the ancillary files generated in the Spitzer Science Center pipeline so that it can either remove or flag artifacts and corrupted data and maximize the sig

Jason X. Prochaska, Hsiao-Wen Chen, J. Christopher Howk, Benjamin J. Weiner

We present results from an analysis of FUSE and HST/STIS spectroscopy of the z_em=0.57 quasar PKS0405-123. We focus on the intervening metal-line systems identified along the sightline and investigate their ionization mechanism, ionization state, and chemical abundances. We identify six OVI absorbers to a 3sigma equivalent width (EW) limit of 60mA. This impl

D. Proga, T. R. Kallman

We explore consequences of a radiation driven disk wind model for mass outflows from active galactic nuclei (AGN). We performed axisymmetric time-dependent hydrodynamic calculations using the same computational technique as Proga, Stone and Kallman (2000). We test the robustness of radiation launching and acceleration of the wind for relatively unfavorable c

Douglas P. Finkbeiner, Glen I. Langston, Anthony H. Minter

We observe significant dust-correlated emission outside of H II regions in the Green Bank Galactic Plane Survey (-4 < b < 4 degrees) at 8.35 and 14.35 GHz. The rising spectral slope rules out synchrotron and free-free emission as majority constituents at 14 GHz, and the amplitude is at least 500 times higher than expected thermal dust emission. When combined

Martin Krause, Max Camenzind

We have used the vectorised and parallelised magnetohydrodynamics code NIRVANA on the NEC SX-5 and the new SX-6 installation in parallel mode to simulate the interaction of jets with a galactic wind that might be typical for the star-bursting radio-galaxies of the early universe. The two simulations, one axisymmetric and one in 3D show that the jet pierces a

Maria Lugaro, Onno Pols, Amanda I. Karakas, Chris A. Tout

The post-Asymptotic Giant Branch (AGB) star HR4049 is in an eccentric binary system with a relatively short period probably surrounded by a dusty circumbinary disk. Extremely anomalous oxygen isotopic ratios, O16/O17 ~ O16/O18 ~ 7, have been measured from CO_2 molecules likely residing in the disk. Such a composition cannot be explained in the framework of A

V. A. Soglasnov, M. V. Popov, N. Bartel, W. Cannon

Giant radio pulses of the millisecond pulsar B1937+21 were recorded with the S2 VLBI system at 1.65 GHz with NASA/JPL's 70-m radio telescope at Tidbinbilla, Australia. These pulses have been observed as strong as 65000 Jy with widths <= 15 ns, corresponding to a brightness temperature T_b >= 5 x 10^39 K, the highest observed in the universe. The vast majorit

John M. Porter, Rene D. Oudmaijer, Debbie Baines

Spectroastrometry is a technique which has the potential to resolve flux distributions on scales of milliarcseconds. In this study, we examine the application of spectroastrometry to binary point sources which are spatially unresolved due to the observational point spread function convolution. The technique uses measurements with sub-pixel accuracy of the po

E. M. Xilouris, A. E. Georgakakis, A. Misiriotis, V. Charmandaris

We investigate the cold and warm dust properties during galaxy interactions using a merging galaxy sample ordered into a chronological sequence from pre- to post-mergers. Our sample comprises a total of 29 merging systems selected to have far-infrared and sub-millimeter observations. The sub-millimeter data are mainly culled from the literature while for 5 g

A. Evans, T. R. Geballe, V. H. Tyne, D. Pollacco

We report the results of monitoring of V4334 Sgr (Sakurai&#39;s Object) at 450 microns and 850 microns with SCUBA on the James Clerk Maxwell Telescope. The flux density at both wavelengths has increased dramatically since 2001, and is consistent with continued cooling of the dust shell in which Sakurai&#39;s Object is still enshrouded, and which still domina

Kevin A. Pimbblet, Michael Bulmer

This article describes a method to turn astronomical imaging into a random number generator by using the positions of incident cosmic rays and hot pixels to generate bit streams. We subject the resultant bit streams to a battery of standard benchmark statistical tests for randomness and show that these bit streams are statistically the same as a perfect rand

Hong Bae Ann, Hyung Mok Lee

Recent high resolution images of spiral galaxies show wide varieties of features including nuclear spirals in the central parts. Some of the galaxies show grand-design nuclear spirals. The morphology of grand-design spirals can be further divided by the openness of the arms: tightly wound ones with winding angle of around 3$π$ radian and open spirals with wi

R. D. Blandford, M. Amin, E. A. Baltz, K. Mandel

Our fundamental lack of understanding of the acceleration of the Universe suggests that we consider a kinematic description. The simplest formalism involves the third derivative of the scale factor through a jerk parameter. A new approach is presented for describing the results of astronomical observations in terms of the contemporary jerk parameter and this

Brice Ménard

We propose a method for detecting gravitational magnification of distant sources, like quasars, due to absorber systems detected in their spectra. We first motivate the use of metal absorption lines rather than Lyman-alpha lines, then we show how to relate the observed moments of the source magnitude distribution to the mass distribution of absorbers. In ord

Y. Y. Kovalev, N. A. Nizhelsky, Yu. A. Kovalev, A. B. Berlin

We present observational results for extragalactic radio sources with milliarcsecond components, obtained with the 600 meter ring radio telescope RATAN-600 from 1st to 22nd December, 1997. For each source, a six frequency broad band radio spectrum was obtained by observing simultaneously with an accuracy up to a minute at 1.4, 2.7, 3.9, 7.7, 13 and 31 cm. Th

S. N. Mitronova, I. D. Karachentsev, V. E. Karachentseva, T. H. Jarrett

An all-sky catalog of 18020 disc-like galaxies is presented. The galaxies are selected from the Extended Source Catalog of the Two Micron All-Sky Survey (XSC 2MASS) basing on their 2MASS axial ratio a/b >= 3. The Catalog contains data on magnitudes of a galaxy in the J, H, K_s bands, its axial ratio, positional angle, index of luminosity concentration, as we

M. D. Maia, E. M. Monte

Some observational constraints on the brane-world based on predictions from specific models in five dimensions, have been recently reported, both on local and cosmological scales. In order to identify the origins of these constraints, the equations of motion of the brane-world are translated to the most general, model-independent (or &#34;covariant&#34;), fo

Reva Kay Williams

I present a theoretical and numerical (Monte Carlo) N-particle analysis of Penrose scattering processes in the ergosphere of a supermassive Kerr black hole. These GR model calculations reveal that the observed high energies and luminosities of quasars and other active galactic nuclei, the collimated jets about the polar axis, and the asymmetrical jets (which

W. de Boer

The diffuse galactic EGRET gamma ray data show a clear excess for energies above 1 GeV in comparison with the expectations from conventional galactic models. The excess is seen with the same spectrum in all sky directions, as expected for Dark Matter (DM) annihilation. This hypothesis is investigated in detail. The energy spectrum of the excess is used to li

O. Cakir, I. Turk Cakir, Z. Kirca

We study the potential of the linear collider (LC) with sqrt{s}=0.5 TeV, linac-ring type ep collider (LCxLHC) with sqrt{s}=3.74 TeV and the large hadron collider (LHC) with sqrt{s}=14 TeV to search for excited neutrinos through transition magnetic type couplings with gauge bosons. The excited neutrino signal and corresponding backgrounds are studied in detai

Vasilisa Shramchenko

Deformations of Dubrovin&#39;s Hurwitz Frobenius manifolds are constructed. The deformations depend on $g(g+1)/2$ complex parameters where $g$ is the genus of the corresponding Riemann surface. In genus one, the flat metric of the deformed Frobenius manifold coincides with a metric associated with a one-parameter family of solutions to the Painlevé-VI equati

Tao Li

A famous example of Casson and Gordon shows that a Haken 3-manifold can have an infinite family of irreducible Heegaard splittings with different genera. In this paper, we prove that a closed non-Haken 3-manifold has only finitely many irreducible Heegaard splittings, up to isotopy. This is much stronger than the Waldhausen conjecture. Another immediate coro

Tao Li

We give a proof of the so-called generalized Waldhausen conjecture, which says that an orientable irreducible atoroidal 3-manifold has only finitely many Heegaard splittings in each genus, up to isotopy. Jaco and Rubinstein have announced a proof of this conjecture using different methods.

A. J. F. Hayes, A. Gilchrist, C. R. Myers, T. C. Ralph

We present a scheme which offers a significant reduction in the resources required to implement linear optics quantum computing. The scheme is a variation of the proposal of Knill, Laflamme, and Milburn, and makes use of an incremental approach to the error encoding to boost probability of success.

Manuel Middendorf, Etay Ziv, Chris Wiggins

Naturally occurring networks exhibit quantitative features revealing underlying growth mechanisms. Numerous network mechanisms have recently been proposed to reproduce specific properties such as degree distributions or clustering coefficients. We present a method for inferring the mechanism most accurately capturing a given network topology, exploiting disc

Ali Eftekhari

The influence of phase transformation-induced plastic deformation in Pd|H system on the electrode surface was investigated. Since the Pd surface is subject of severe plastic deformation during this process, the structure and roughness of the electrode surface significantly changes. Quantitative analysis of the electrode surfaces for comparative study of such

Arnab Mukherjee, Biman Bagchi

Rotational friction on proteins and macromolecules is known to derive contributions from at least two distinct sources -- hydrodynamic (due to viscosity) and dielectric friction (due to polar interactions). In the existing theoretical approaches, the effect of the latter is taken into account in an {\it ad hoc} manner, by increasing the size of the protein w

S. G. Low

The Hilbert space of the unitary irreducible representations of a Lie group that is a quantum dynamical group are identified with the quantum state space. Hermitian representation of the algebra are observables. The eigenvalue equations for the representation of the set of Casimir invariant operators define the field equations of the system. A general class

Tom Meyerovitch

In a previous paper by the author, it was shown that the One sided Dyck is uniquely ergodic with respect to the one sided-tail relation, where the tail invariant probability is also shift invariant and obtains the topological entropy. In this paper we show that the two sided Dyck has a double-tail invariant probability, which is also shift invariant, with en

Michael Zarichnyi

We provide an example of a zero-dimensional compact metric space $X$ and its closed subspace $A$ such that there is no continuous linear extension operator for the Lipschitz pseudometrics on $A$ to the Lipschitz pseudometrics on $X$. The construction is based on results of A. Brudnyi and Yu. Brudnyi concerning linear extension operators for Lipschitz functio

Michael T Lacey, Xiaochun Li

For a Schwartz function $f$ on the plane and a non-zero $v\in\ZR^2$ define the Hilbert transform of $f$ in the direction $v$ to be $$ H_vf(x)=\text{p.v.}\int_\ZR f(x-vy) \frac{dy}y $$ Let $ζ$ be a Schwartz function with frequency support in the annulus $1\le| ξ|\le2$. We prove that the maximal operator $$ \sup_{\abs v=1}\abs{H_vζ* f} $$ maps $L^2$ into weak

Mathias Schulze

This article describes a normal form algorithm for the Brieskorn lattice of an isolated hypersurface singularity. It is the basis of efficient algorithms to compute the Bernstein-Sato polynomial, the complex monodromy, and Hodge-theoretic invariants of the singularity such as the spectral pairs and good bases of the Brieskorn lattice. The algorithm is a vari

Gregory Gabadadze

I briefly review the arguments why the braneworld models with infinite-volume extra dimensions could solve the cosmological constant problem, evading Weinberg&#39;s no-go theorem. Then I discuss in detail the established properties of these models, as well as the features which should be studied further in order to conclude whether these models can truly sol

G. L. Kane, M. J. Perry, A. N. Zytkow

We propose an approach to explaining why naive large quantum fluctuations are not the right estimate for the cosmological constant. We argue that the universe is in a superposition of many vacua, in such a way that the resulting fluctuations are suppressed by level repulsion to a very small value. The approach combines several aspects of string theory and th

P. Moskal

We present results of investigations aiming to determine the hadronic interaction of eta and eta-prime mesons with nucleons. Inferences are based on comparisons of both the differential cross sections and the close-to-threshold excitation functions for the p p --> p p eta and p p --> p p eta-prime reactions with predictions based on the assumption that the k

Alessandro Nagar, Guillermo Diaz

This article reports results from numerical simulations of the gravitational radiation emitted from nonrotating relativistic stars as a result of the axisymmetric accretion of layers of perfect fluid matter, shaped in the form of quadrupolar shells. We adopt a {\em hybrid} procedure where we evolve numerically the polar nonspherical perturbations equations o

Jørgen Villadsen

We investigate the possibility of modelling the syntax and semantics of natural language by constraints, or rules, imposed by the multi-dimensional type theory Nabla. The only multiplicity we explicitly consider is two, namely one dimension for the syntax and one dimension for the semantics, but the general perspective is important. For example, issues of pr

Yong-Gang Yang, Peng-Gang Yin, Xin-Qi Li anf YiJing Yan

Recent experiments indicated that disorder effect in DNA may lead to a transition of the charge transport mechanism from band resonant tunnelling to thermal activated hopping. In this letter, based on Mott&#39;s variable-range hopping theory we present a kinetic study for the charge transport properties of DNA molecules. Beyond the conventional argument in l

Dipti Banerjee

When two non-identical quasi-particles in the Hall fluid encircle each other, relative AB type phase developes.As the quasi-particles advance towards the edge in a similar circular way, the developed current should have connection with this AB type phase through the {\it Shift} quantum number or Berry&#39;s topological phase. We have pointed out the role of

J. Chakhalian, Z. Salman, J. Brewer, A. Froese

Muon spin relaxation measurements around the 25 K metal-insulator transition in Li$_{0.9}$Mo$_6$O$_{17}$ elucidate a profound role of disorder as a possible mechanism for this transition. The relaxation rate $1/T_1$ and the muon Knight shift are incompatible with the transition to a SDW state and thus exclude it.

K. Malarz, S. Galam

We report site percolation thresholds for square lattice with neighbor interactions at various increasing ranges. Using Monte Carlo techniques we found that nearest neighbors (N$^2$), next nearest neighbors (N$^3$), next next nearest neighbors (N$^4$) and fifth nearest neighbors (N$^6$) yield the same $p_c=0.592...$. At odds, fourth nearest neighbors (N$^5$)

R. H. He, D. L. Feng

The implementation of global non-analytical fit is exemplified by its application to the spectral analysis of the complex lineshape of Bi$_2$Sr$_2$CaCu$_2$O$_{8+δ}$ at $(π,0)$. It deals with properly a multi-level globality in the fitting parameters and efficiently the non-analytical evaluation of the fitting function, thus exhibiting a potential applicabili