August 2004 arXiv papers — page 9

Andrew Cumming

Radial velocity surveys are beginning to reach the time baselines required to detect Jupiter analogs, as well as sub-Saturn mass planets in close orbits. Therefore it is important to understand the sensitivity of these surveys at long periods and low amplitudes. In this paper, I derive analytic expressions for the detectability of planets at both short and l

L. K. Hunt, M. A. Malkan

Why are the nuclei of some galaxies more active than others? If most galaxies harbor a central massive black hole, the main difference is probably in how well it is fueled by its surroundings. We investigate the hypothesis that such a difference can be seen in the detailed circumnuclear morphologies of galaxies using several quantitatively defined features,

Catherine Vlahakis, Stephen Eales, Loretta Dunne

We discuss the progress of the SCUBA Local Universe Galaxy Survey (SLUGS), the first large, statistical sub-mm survey of the local universe. Since our original survey of a sample of 104 IRAS-selected galaxies we have recently completed a sample of 78 Optically-Selected galaxies. Since SCUBA is sensitive to the large proportion of dust too cold to be detected

J. K. Smith, A. J. Bunker, N. P. Vogt, R. G. Abraham

In this letter we present the first 3D spectroscopic study of H-alpha emission in a z ~ 1 field galaxy with an integral field unit. Using the CIRPASS spectrograph on Gemini-South we map the spatial and velocity distribution of H-alpha emission in the z=0.819 galaxy CFRS 22.1313. We detect two H-alpha emitting regions with a velocity separation of 220+/-10 km

Ph. Brax, C. van de Bruck, A. -C. Davis

The chameleon mechanism is a way to give an effective mass to a light scalar field via field self-interaction and interaction with matter. We study this mechanism in models in which the couplings are field dependent and find that the properties are very different from the case of constant couplings. The consequence of a runaway potential for the radion field

J. Einasto, E. Tago, M. Einasto, E. Saar

We find clusters and superclusters of galaxies using the Data Release 1 of the Sloan Digital Sky Survey. Density fields with smoothing lengthst of 10 and 0.8 Mpc/h are calculated. We found that galaxies and clusters in a high-density environment have luminosities that are five to ten times higher than in a low-density environment. Numerical simulations show

A. Recio-Blanco, G. Piotto, F. De Angeli, S. Cassisi

We present distance modulus and reddening determinations for 72 Galactic globular clusters from the homogeneous photometric database of Piotto et al. (2002), calibrated to the HST flight F439W and F555W bands. The distances have been determined by comparison with theoretical absolute magnitudes of the ZAHB. For low and intermediate metallicity clusters, we h

Prasad Subramanian, Peter A. Becker

We use a generic stochastic acceleration formalism to examine the power $L_{\rm in}$ (${\rm erg s^{-1}}$) input to nonthermal electrons that cause noise storm continuum emission. The analytical approach includes the derivation of the Green's function for a general second-order Fermi process, and its application to obtain the particular solution for the n

K. S. Cheng, Ronald E. Taam, W. Wang

The general properties of the non-thermal non-pulsed X-ray emission of rotation powered pulsars are investigated in the context of a pulsar wind nebula model. An examination of the observed X-ray emission from a sample of 23 pulsars from ASCA in the energy range between 2-10 keV reveals that the relation of X-ray luminosity, $L_x$, to the pulsar spin down po

Frederick K. Lamb, Wenfei Yu

Observations made using the Rossi X-ray Timing Explorer have shown that accreting weak-field neutron stars in low-mass X-ray binary systems (LMXBs) produce three distinct types of millisecond X-ray oscillations that can be used to determine the spin rates and estimate the magnetic fields of these stars. These oscillations show that more than two dozen neutro

S. E. Thorsett, R. J. Dewey, I. H. Stairs

We have recently measured the angle between the spin and orbital angular momenta of PSR B1534+12 to be either 25+/-4 deg or 155+/-4 deg. This misalignment was almost certainly caused by an asymmetry in the supernova explosion that formed its companion neutron star. Here we combine the misalignment measurement with measurements of the pulsar and companion mas

I. H. Stairs, S. E. Thorsett, Z. Arzoumanian

In relativistic gravity, a spinning pulsar will precess as it orbits a compact companion star. We have measured the effect of such precession on the average shape and polarization of the radiation from PSR B1534+12. We have also detected, with limited precision, special-relativistic aberration of the revolving pulsar beam due to orbital motion. Our observati

Eric F. Bell

In a Lambda CDM Universe, galaxies grow in mass both through star formation and through addition of already-formed stars in galaxy mergers. Because of this partial decoupling of these two modes of galaxy growth, I discuss each separately in this biased and incomplete review of galaxy assembly; first giving an overview of the cosmic-averaged star formation hi

S. Ferraz-Mello, T. A. Michtchenko, C. Beauge

This paper is a review of the dynamics of a system of planets. It includes the study of averaged equations in both non-resonant and resonant systems and shows the great deal of situations in which the angle between the two semi-major axes oscillates around a constant value. It introduces the Hamiltonian equations of the $N$-planet problem and Poincaré's

Wayne Hu, Ryan Scranton

The integrated Sachs-Wolfe (ISW) effect in the cosmic microwave background (CMB) as measured through its correlation with galaxies provides a unique opportunity to study the dynamics of the dark energy through its large scale clustering properties. Ultimately, a deep all-sky galaxy survey out to z~2 can make a 10sigma or ~10% measurement of the correlation a

Mei Huang, Igor A. Shovkovy

The Debye and Meissner screening masses of the gluons and the photon in neutral and beta-equilibrated dense two-flavor quark matter are calculated. The results are presented in a general form that can be used in gapped as well as gapless color superconducting phases. The results for the magnetic screening masses indicate that the system develops a chromomagn

Arlette R. C. Baljon, Maarten H. M. Van Weert, Regina Barber DeGraaff, Rajesh Khare

Glass transition behavior of nanoscopically thin polymer films is investigated by means of molecular dynamics simulations. A thin polymer film that is composed of bead-spring model chains and supported on an idealized, fcc lattice substrate surface is studied in this work.

Zoltan Ligeti

The status of CP violation and the CKM matrix is reviewed. Direct CP violation in B decay has been established and the measurement of sin(2beta) in ψK modes reached 5% accuracy. I discuss the implications of these, and of the possible deviations of the CP asymmetries in b->s modes from that in ψK. The first meaningful measurements of alpha and gamma are expl

J. LaChapelle

For gauge theories with direct product internal symmetry groups, the relationship between internal quantum numbers (charges) and coupling strengths is examined. In these types of theories, the Lagrangian density may contain non-trivial factors multiplying the matter field terms, and these factors can modify the interaction coupling strengths i.e., the gauge/

S. A. Frolov, I. Y. Park, A. A. Tseytlin

We revisit the computation (hep-th/0306130) of 1-loop AdS_5 x S^5 superstring sigma model correction to energy of a closed circular string rotating in S^5. The string is spinning around its center of mass with two equal angular momenta J_2=J_3 and its center of mass angular momentum is J_1. We revise the argument in hep-th/0306130 that the 1-loop correction

Margaret E. Wessling

The 1/N_c expansion for negative-parity heavy pentaquarks is developed using the formalism introduced for excited baryons in large N_c. Relations are found between the mass splittings of these pentaquarks and those of nonexotic baryons.

Guo-meng Zhao

The polaron binding energy E_{p} in undoped parent cuprates has been determined to be about 1.0 eV from the unconventional oxygen-isotope effect on the antiferromagnetic ordering temperature. The deduced value of E_{p} is in quantitative agreement with that estimated from independent optical data and that estimated theoretically from the measured dielectric

R. Sekhar Chivukula, Hong-Jian He, Masafumi Kurachi, Elizabeth H. Simmons

Recently Barbieri, et al. have introduced a formalism to express the deviations of electroweak interactions from their standard model forms in "universal" theories, i.e. theories in which the corrections due to new physics can be expressed solely by modifications to the two-point correlation function of electroweak gauge currents of fermions. The par

J. M. Diego, P. Protopapas, H. B Sandvik, M. Tegmark

We revisit the issue of non-parametric gravitational lens reconstruction and present a new method to obtain the cluster mass distribution using strong lensing data without using any prior information on the underlying mass. The method relies on the decomposition of the lens plane into individual cells. We show how the problem in this approximation can be exp

Iosif Bena, Per Kraus

We discuss some aspects of the recently discovered BPS black ring solutions in terms of the AdS/CFT correspondence. In the type IIB frame in which the black ring carries the charges of the D1-D5-P system, we propose a microscopic description of the rings in the orbifold CFT governing this system. In our proposal, the CFT effectively splits into two parts: on

Nissan Itzhaki, John McGreevy

We propose a duality between the large-N gauged harmonic oscillator and a novel string theory in two dimensions.

N. R. Butler, T. Sakamoto, M. Suzuki, N. Kawai

We report High Energy Transient Explorer 2 (HETE-2) Wide Field X-ray Monitor/French Gamma Telescope observations of XRF030723 along with observations of the XRF afterglow made using the 6.5m Magellan Clay telescope and the Chandra X-ray Observatory. The observed peak energy E_pk_obs of the nu F_nu burst spectrum is found to lie within (or below) the WXM 2-25

B. Chandrasekhar

We extend the results of hep-th/0310137 to show that a general classical action for D=2, N=2 sigma models on a non(anti)commutative superspace is not standard and contains infinite number of terms, which depend on the determinant of the non(anti)commutativity parameter, C^{αβ}. We show that using Kahler normal coordinates the action can be written in a manif

J. Li, Z. P. Zhang, A. J. Schwartz

We have searched for mixing in the D0-D0bar system by measuring the decay-time distribution of D0->K+pi- decays. The analysis uses 90 fb^{-1} of data collected by the Belle detector at the KEKB e+e- collider. We fit the decay-time distribution for the mixing parameters x' and y' and also for the parameter R_D, which is the ratio of the rate for the d

S. Khlebnikov

In a uniform ring-shaped one-dimensional superfluid, quantum fluctuations that unwind the order parameter need to transfer momentum to quasiparticles (phonons). We present a detailed calculation of the leading exponential factor governing the rate of such phonon-assisted tunneling in a weakly-coupled Bose gas at a low temperature $T$. We also estimate the pr

A. Rosch, J. Paaske, J. Kroha, P. Wölfle

While the properties of the Kondo model in equilibrium are very well understood, much less is known for Kondo systems out of equilibrium. We study the properties of a quantum dot in the Kondo regime, when a large bias voltage V and/or a large magnetic field B is applied. Using the perturbative renormalization group generalized to stationary nonequilibrium si

Richard Massey, Alexandre Refregier

The shapelets method for image analysis is based upon the decomposition of localised objects into a series of orthogonal components with convenient mathematical properties. We extend the "Cartesian shapelet" formalism from earlier work, and construct "polar shapelet" basis functions that separate an image into components with explicit rotatio

Jürgen König, Yuval Gefen, Alessandro Silva

In a recent Letter, Jiang, Sun, Xie and Wang [Phys. Rev. Lett. 93, 076802 (2004), cond-mat/0408261] study transport through an interacting quantum dot embedded in one arm of an Aharonov-Bohm interferometer. Based on a theoretical analysis of the Aharonov-Bohm oscillation amplitude, Jiang {\it et al.} claim, contrary to earlier work by two of us, that at fini

Sanjoy Datta, Arnab Das, Sudhakar Yarlagadda

We derive an effective polaronic interaction Hamiltonian, {\it exact to second order in perturbation}, for the spinless one-dimensional Holstein model. The small parameter is given by the ratio of the hopping term ($t$) to the polaronic energy ($g^2 ω_0$) in all the region of validity for our perturbation; however, the exception being the regime of extreme a

C. -P. Liu, R. G. E. Timmermans

The nuclear physics relevant to the electric dipole moment (EDM) of the deuteron is addressed. The general operator structure of the $P$- and $T$-odd nucleon-nucleon interaction is discussed and applied to the two-body contributions of the deuteron EDM, which can be calculated in terms of $P$- and $T$-odd meson-nucleon coupling constants with only small mode

T. Brunier, V. K. Onemli, R. P. Woodard

We work in the locally de Sitter background of an inflating universe and consider a massless, minimally coupled scalar with a quartic self-interaction. We use dimensional regularization to compute the fully renormalized scalar self-mass-squared at one and two loop order for a state which is released in Bunch-Davies vacuum at t=0. Although the field strength

X. S. Chen, V. Dohm

We study the bulk and finite-size critical behavior of the O$(n)$ symmetric $ϕ^4$ theory with spatially anisotropic interactions of non-cubic symmetry in $d<4$ dimensions. In such systems of a given $(d,n)$ universality class, two-scale factor universality is absent in bulk correlation functions, and finite-size scaling functions including the Privman-Fisher

A. Cucchieri, T. Mendes, A. Mihara

We present a numerical study of the ghost-gluon vertex and of the corresponding renormalization function \widetilde{Z}_1(p^2) in minimal Landau gauge for SU(2) lattice gauge theory. Data were obtained for three different lattice volumes (V = 4^4, 8^4, 16^4) and for three lattice couplings β= 2.2, 2.3, 2.4. Gribov-copy effects have been analyzed using the so-

Xinwu Cao

The dust clouds in the torus of the quasar are irradiated by the central source, and the clouds at the inner radius of the torus re-radiate mostly in the near-infrared (NIR) wavebands. The ratio of the near-infrared luminosity to the bolometric luminosity L_NIR/L_bol can therefore reflect the torus geometry to some extent. We find a significant correlation b

A. Meziane, M. Tahiri

The quantization of gauge-affine gravity within the superfiber bundle formalism is proposed. By introducing an even pseudotensorial 1-superform over a principal superfibre bundle with superconnection, we obtain the geometrical Becchi-Rouet-Stora-Tyutin (BRST) and anti-BRST transformations of the fields occurring in such a theory. Reducing the four-dimensiona

A. C. Aguilar, A. A. Natale

We study numerically the Schwinger-Dyson equations for the coupled system of gluon and ghost propagators in the Landau gauge and in the case of pure gauge QCD. We show that a dynamical mass for the gluon propagator arises as a solution while the ghost propagator develops an enhanced behavior in the infrared regime of QCD. Simple analytical expressions are pr

J. A. Acosta-Pulido, M. Kun, P. Abraham, A. Kospal

(Abridged) We studied the brightness and spectral evolution of the young eruptive star V1647 Ori during its recent outburst in the period 2004 February - 2006 Sep. We performed a photometric follow-up in the bands V, R_C, I_C, J, H, K_s as well as visible and near-IR spectroscopy. The main results are as follows: The brightness of V1647 Ori stayed more than

Makoto Ideta, Junichiro Makino

We have investigated whether or not a tidal stripping scenario can reproduce the observed surface-brightness profile of omega Centauri using N-body simulations. Assuming that the progenitor of omega Centauri is a dwarf elliptical galaxy, we model it with a King model with a core radius being the same as that of omega Centauri. A dark matter halo of the dwarf

BES Collaboration

Decays of the $ψ(2S)$ into Vector plus Pseudoscalar meson final states have been studied with 14 million $ψ(2S)$ events collected with the BESII detector. Branching fractions of $ψ(2S) \rarϕη$, $ϕ\etap$, and $ω\etap$, and upper limits of $ψ(2S) \rar ϕ\piz$ and $ωη$ are obtained: $B(ψ(2S) \rarϕη) = (3.3\pm 1.1 \pm 0.5) \times 10^{-5}$, $B(ψ(2S) \rarϕ\etap) =

Toshifumi Jittoh, Shigeki Matsumoto, Joe Sato, Yoshio Sato

We study the decay process of an unstable quantum system, especially the deviation from the exponential decay law. We show that the exponential period no longer exists in the case of the s-wave decay with small $Q$ value, where the $Q$ value is the difference between the energy of the initially prepared state and the minimum energy of the continuous eigensta

Greg Friedman

We show that there exist non-trivial piecewise-linear (PL) knots with isolated singularities $S^{n-2}\subset S^n$, $n\geq 5$, whose complements have the homotopy type of a circle. This is in contrast to the case of smooth, PL locally-flat, and topological locally-flat knots, for which it is known that if the complement has the homotopy type of a circle, then

Masahiro Kawasaki, Kazunori Kohri, Takeo Moroi

We study the big-bang nucleosynthesis (BBN) with the long-lived exotic particle, called X. If the lifetime of X is longer than \sim 0.1 sec, its decay may cause non-thermal nuclear reactions during or after the BBN, altering the predictions of the standard BBN scenario. We pay particular attention to its hadronic decay modes and calculate the primordial abun

Tao Huang, Xing-Gang Wu

A model for the twist-3 wave function $ψ_p(x,\mathbf{k_\perp})$ of the pion has been constructed based on the moment calculation by applying the QCD sum rules, whose distribution amplitude has a better end-point behavior than that of the asymptotic one. With this model wave function, the twist-3 contributions including both the usual helicity components ($λ_

K. Abe

We report recent results on the properties of the X(3872) produced via the B+ --> K+ X(3872) decay process. We observe X -->pi+pi-pi0 J/psi decays where the 3pi invariant masses cluster near the upper kinematic boundary suggesting that they originate from sub-threshold decays to virtual omega(782) mesons. This is consistent with expectations for a DD*-bar bo

Muneya Matsui, Akimichi Takemura

We propose improvements in numerical evaluation of symmetric stable density and its partial derivatives with respect to the parameters. They are useful for more reliable evaluation of maximum likelihood estimator and its standard error. Numerical values of the Fisher information matrix of symmetric stable distributions are also given. Our improvements consis

V P Belavkin

Introducing contravariant trace-densities for quantum states, we restore one to one correspondence between quantum operations described by normal CP maps and their trace densities as Hermitian positive operator-valued contravariant kernels. The CB-norm distance between two quantum operations with type one input algebras is explicitly expressed in terms of th

Matias Aiello, Rafael Ferraro, Gaston Giribet

The exact five-dimensional charged black hole solution in Lovelock gravity coupled to Born-Infeld electrodynamics is presented. This solution interpolates between the Hoffmann black hole for the Einstein-Born-Infeld theory and other solutions in the Lovelock theory previously studied in the literature. The conical singularity of the metric around the origin

Paolo Amore

By means of a variational approach we find new series representations both for well known mathematical constants, such as $π$ and the Catalan constant, and for mathematical functions, such as the Riemann zeta function. The series that we have found are all exponentially convergent and provide quite useful analytical approximations. With limited effort our me

S. E. Ahnert, M. C. Payne

We propose an experimental setup for the implementation of weak measurements in the context of the gedankenexperiment known as Hardy&#39;s Paradox. As Aharonov et al. showed, these weak values form a language with which the paradox can be resolved. Our analysis shows that this language is indeed consistent and experimentally testable. It also reveals exactly

T. Shi, Ying Li, Z. Song, C. P. Sun

We show that a perfect quantum state transmission can be realized through a spin chain possessing a commensurate structure of energy spectrum, which is matched with the corresponding parity. As an exposition of the mirror inversion symmetry discovered by Albanese et. al (quant-ph/0405029), the parity matched the commensurability of energy spectra help us to

Maurice Robert Kibler, Tidjani Negadi

The discrete spectrum of a q-analogue of the hydrogen atom is obtained from a deformation of the Pauli equations. As an alternative, the spectrum is derived from a deformation of the four-dimensional oscillator arising in the application of the Kustaanheimo-Stiefel transformation to the hydrogen atom. A model of the 2s-2p Dirac shift is proposed in the conte

Bryan Eastin, Steven T. Flammia

Q-circuit is a list of macros that greatly simplifies the construction of quantum circuit diagrams (QCDs) in LaTeX with the help of the Xy-pic package. This tutorial should help the reader acquire the skill to render arbitrary QCDs in a matter of minutes. Q-circuit is available for free at http://info.phys.unm.edu/Qcircuit/.

Detlef Duerr, Sheldon Goldstein, Roderich Tumulka, Nino Zanghi

We discuss a recently proposed extension of Bohmian mechanics to quantum field theory. For more or less any regularized quantum field theory there is a corresponding theory of particle motion, which in particular ascribes trajectories to the electrons or whatever sort of particles the quantum field theory is about. Corresponding to the nonconservation of the

B. J. Powell

We report first principles density functional calculations for 5,6-dihydroxyindole-2-carboxylic acid (DHICA) and several reduced forms. DHICA and 5,6-dihydroxyindole (DHI) are believed to be the basic building blocks of the eumelanins. Our results show that carboxylation has a significant effect on the physical properties of the molecules. In particular, the

Guido R. Mocken, Christoph H. Keitel

A procedure to calculate the radiation spectrum emitted by an arbitrarily prepared Dirac wave packet is developed. It is based on the Dirac charge current and classical electrodynamic theory. Apart from giving absolute intensity values, it is exact in terms of relativistic retardation effects and angular dependence. We employ a laser driven free electron to

S. Jan, G. Santin, D. Strul, S. Staelens

Monte Carlo simulation is an essential tool in emission tomography that can assist in the design of new medical imaging devices, the optimization of acquisition protocols, and the development or assessment of image reconstruction algorithms and correction techniques. GATE, the Geant4 Application for Tomographic Emission, encapsulates the Geant4 libraries to

Willem G. J. Langeveld

Lelaps is a fast detector simulation program which reads StdHep generator files and produces SIO or LCIO output files. It swims particles through detectors taking into account magnetic fields, multiple scattering and dE/dx energy loss. It simulates parameterized showers in EM and hadronic calorimeters and supports gamma conversions and decays.

M. C. Martins, A. M. Costa, J. P. Santos, F. Parente

Energies of two-electron one-photon transitions from initial double K-hole states were computed using the Dirac-Fock model. The transition energies of competing processes, the K$α$ hypersatellites, were also computed. The results are compared to experiment and to other theoretical calculations.

Yukio Saito, Hiroyuki Hyuga

Recently the first chemical systems which show the amplification of enantiometric excess (ee) was found. Inspired by these experiments, we propose a few chemical reaction models in a closed system. The reactions consist of autocatalytic production of chiral molecules and their decomposition processes. By means of flow diagrams in the phase space of enatiomet

A. Ghasemizad, M. Kamran

One of the best methods in inertial confinement fusion (ICF) is the concept of central spark ignition, consisting of two distinct regions named as hot and cold regions and formed by hydro-dynamical implosion of fuel micro-sphere central spark ignition method in inertial fusion and fuel pellet design condition in fusion power plant has been investigated and f

J. A. Caballero, T. W. Donnelly, M. C. Martínez, E. Moya de Guerra

At present there exists a great interest in the search for evidence of possible modification of the nucleon form factors inside the nuclear medium. Recent theoretical work predict changes in the form factors within the experimental limits. Importantly, the longitudinal to sideways transferred polarization ratio has been identified as being ideally suited for

S. Adhikari, C. Samanta

Variation of nuclear shell effects with nucleon numbers are evaluated using the modified Bethe-Weizsacker mass formula (BWM) and the measured atomic masses. The shell effects at magic neutron numbers N = 8, 20, 28, 50, 82 and 126 and magic proton numbers Z = 8, 20, 28,50 and 82 are found to vary rapidly approaching the drip lines. The shell effect due to one

S. Typel, G. Baur

We study low-lying multipole strength in neutron-halo nuclei. The strength depends only on a few low-energy constants: the neutron separation energy, the asymptotic normalization coefficient of the bound state wave function, and the scattering length that contains the information on the interaction in the continuum. The shape of the transition probability sh

Adonai S. Sant&#39;Anna

In a recent paper Andrei N. Soklakov explained the foundations of the Lagrangian formulation of classical particle mechanics by means of Kolmogorov complexity. In the present paper we use some of Soklakov ideas in order to derive the second law of thermodynamics. Our main result is that the complexity of a thermal system corresponds to its entropy.

Alex Kasman

In this note, we apply canonical quantization to the self-dual particle system describing the motion of poles to a higher rank solution of the KP hierarchy, explicitly determining both the quantum Hamiltonian and the wave function. It is verified that the quantum Hamiltonian is trivially bispectral (that is, that the wave function can be taken to be symmetri

Michael Gekhtman, Alex Kasman

We provide a determinantal formula for tau-functions of the KP hierarchy in terms of rectangular, constant matrices $A$, $B$ and $C$ satisfying a rank one condition. This result is shown to generalize and unify many previous results of different authors on constructions of tau-functions for differential and difference integrable systems from square matrices

Yuri N. Fedorov, Bozidar Jovanovic

This paper is a review of recent results on integrable nonholonomic geodesic flows of left--invariant metrics and left- and right--invariant constraint distributions on compact Lie groups.

Edward Swartz

We present a number of lower bounds for the h-vectors of k-CM, broken circuit and independence complexes. These lead to bounds on the coefficients of the characteristic and reliability polynomials of matroids. The main techniques are the use of series and parallel constructions on matroids and the short simplicial h-vector for pure complexes.

Erik Boczko, Todd Young

We study a finite uni-directional array of &#34;cascading&#34; or &#34;threshold coupled&#34; chaotic maps. Such systems have been proposed for use in nonlinear computing and have been applied to classification problems in bioinformatics. We describe some of the attractors for such systems and prove general results about their basins of attraction. In partic

Ramiro de la Vega

Under Jensen&#39;s Diamond Principle, we show how to construct a large compact S-space while having some control over its group of autohomeomorphisms. In particular we can make the space rigid or h-homogeneous (i.e. any two clopen subsets are homeomorphic). We also get a space which is B-homogeneous and not h-homogeneous, partially answering a question of M.

Brendan Hassett

This semi-expository paper discusses the log minimal model program as applied to the moduli space of curves, especially in the case of curves of genus two. Log canonical models for these moduli spaces can often be constructed using the techniques of Geometric Invariant Theory. In genus two, this boils down to the invariant theory of binary sextics, which was

János Kollár, Karen E. Smith, Alessio Corti

We correct a misattribution in our book.

S. Kaplan, A. Shapiro, M. Teicher

We combine the newly discovered technique, which computes explicit formulas for the image of an algebraic curve under rational transformation, with techniques that enable to compute braid monodromies of such curves. We use this combination in order to study properties of the braid monodromy of the image of curves under a given rational transformation. A desc

S. Caenepeel, F. Van Oystaeyen, Y. H. Zhang

We consider the Brauer group ${\rm BM}&#39;(k,G)$ of a group $G$ (finite or infinite) over a commutative ring $k$ with identity. A split exact sequence $$1\longrightarrow {\rm Br}&#39;(k)\longrightarrow {\rm BM}&#39;(k,G)\longrightarrow {\rm Gal}(k,G) \longrightarrow 1$$ is obtained. This generalizes the Fröhlich-Wall exact sequence from the case of a field

Mark Brightwell, Paul Turner

There are two natural candidates for the group of relative Cheeger-Simons differential characters. The first directly extends the work of Cheeger and Simons and the second extends the description given by Hopkins and Singer of the Cheeger-Simons group as the homology of a certain cochain complex. We discuss both approaches and relate the two relative groups.

Ross Pinsky

Consider classical solutions to the parabolic reaction diffusion equation $$ &u_t =Lu+f(x,u), (x,t)\in R^n\times(0,\infty); &u(x,0) =g(x)\ge0, x\in R^n; &u\ge0, $$ where $$ L=\sum_{i,j=1}^na_{i,j}(x)\frac{\partial^2}{\partial x_i \partial x_j}+\sum_{i=1}^nb_i(x)\frac\partial{\partial x_i} $$ is a non-degenerate elliptic operator, $g\in C(R^n)$ and the reacti

Michael Joswig, Marc E. Pfetsch

Morse matchings capture the essential structural information of discrete Morse functions. We show that computing optimal Morse matchings is NP-hard and give an integer programming formulation for the problem. Then we present polyhedral results for the corresponding polytope and report on computational results.

Valerij G. Bardakov

We construct a linear representation of the group IA(F_n) of IA-automorphisms of a free group F_n, an extension of the Gassner representation of the pure braid group P_n. Although the problem of faithfulness of the Gassner representation is still open for n > 3, we prove that the restriction of our representation to the group of basis conjugating automorphis

Tomonari Suzuki

In this paper, we prove the following theorem: Let {T(t) : t >= 0} be a one-parameter continuous semigroup of mappings on a subset C of a Banach space E. The set of fixed points of T(t) is denoted by F(T(t)) for each t >= 0. Then cap_{t >= 0} F(T(t)) = F(T(1)) cap F(T(sqrt 2)) holds. Using this theorem, we discuss convergence theorems to a common fixed point

E. Glasner, B. Weiss

This article reviews a generous sampling of both classical and more recent results on the interplay between measurable and topological dynamics. In the first part we have surveyed the strong analogies between ergodic theory and topological dynamics as shown in the treatment of recurrence phenomena, equicontinuity and weak mixing, distality and entropy. The p

Chunhui Lai

A sequence $S$ is potentially $K_{p_{1},p_{2},...,p_{t}}$ graphical if it has a realization containing a $K_{p_{1},p_{2},...,p_{t}}$ as a subgraph, where $K_{p_{1},p_{2},...,p_{t}}$ is a complete t-partite graph with partition sizes $p_{1},p_{2},...,p_{t} (p_{1}\geq p_{2}\geq ...\geq p_{t} \geq 1)$. Let $σ(K_{p_{1},p_{2},...,p_{t}}, n)$ denote the smallest d

Nathan Brownlowe, Iain Raeburn

We consider Exel&#39;s new construction of a crossed product of a C*-algebra A by an endomorphism α. We prove that this crossed product is universal for an appropriate family of covariant representations, and we show that it can be realised as a relative Cuntz-Pimsner algbera. We describe a necessary and sufficient condition for the canonical map from A into

Christoph Gugg, Jinqiao Duan

We consider the stochastic Burgers equation $ \dnachd{t} ψ(t,r) = Δψ(t,r) + \nabla ψ^2(t,r)+\sqrt{γψ(t,r)} η(t,r) $ with periodic boundary conditions, where $t \ge 0,$ $r \in [0,1],$ and $η$ is some space-time white noise. A certain Markov jump process is constructed to approximate a solution of this equation.}

Wei Wang, Jianhua Sun, Jinqiao Duan

The Swift-Hohenberg fluid convection system with both local and nonlocal nonlinearities under the influence of white noise is studied. The objective is to understand the difference in the dynamical behavior in both local and nonlocal cases. It is proved that when sufficiently many of its Fourier modes are forced, the system has a unique invariant measure, or

S. Amghibech

In this note we provide a simple formula of general term of recurrent sequence.

Andrew Granville, Greg Martin

This is a survey article on prime number races. Chebyshev noticed in the first half of the nineteenth century that for any given value of x, there always seem to be more primes of the form 4n+3 less than x then there are of the form 4n+1. Similar observations have been made with primes of the form 3n+2 and 3n+1, with primes of the form 10n+3/10n+7 and 10n+1/

Marina Kozlova, Paavo Salminen

In this paper excursions of a stationary diffusion in stationary state are studied. In particular, we compute the joint distribution of the occupation times $I^{(+)}_t$ and $I^{(-)}_t$ above and below, respectively, the observed level at time $t$ during an excursion. We consider also the starting time $g_t$ and the ending time $d_t$ of the excursion (straddl

Cesar J. Niche

For many classes of symplectic manifolds, the Hamiltonian flow of a function with sufficiently large variation must have a fast periodic orbit. This principle is the base of the notion of Hofer-Zehnder capacity and some other symplectic invariants and leads to numerous results concerning existence of periodic orbits of Hamiltonian flows. Along these lines, w

Michael Joswig

As a new concept tropical halfspaces are introduced to the (linear algebraic) geometry of the tropical semiring (R,min,+). This yields exterior descriptions of the tropical polytopes that were recently studied by Develin and Sturmfels in a variety of contexts. The key tool to the understanding is a newly defined sign of the tropical determinant, which shares

A. J. Berndsen, J. M. Cline

Brane Gas Cosmology is an M-theory motivated attempt to reconcile aspects of the standard cosmology based on Einstein&#39;s theory of general relativity. Dilaton gravity, when incorporating winding p-brane states, has verified the Brandenberger--Vafa mechanism --a string-motivated conjecture which explains why only three of the nine spatial dimensions predic

Gerard &#39;t Hooft

A discussion is given of the confinement mechanism in terms of the Abelian projection scheme, for a general number Nc of colors. There is a difficulty in the Nc to infinity limit that requires a careful treatment, as the charges of the condensing magnetic monopoles tend to infinity. We suggest that Bose condensation of electric or magnetic charges is indicat

P. Kosinski, P. Maslanka

The global version of the quantum symmetry defined by Chaichian et al (hep-th/0408069) is constructed.

Robert G. Leigh, Djordje Minic

We study the large N (planar) limit of pure SU(N) 2+1 dimensional Yang-Mills theory (YM_{2+1}) using a gauge-invariant matrix parameterization introduced by Karabali and Nair. This formulation crucially relies on the properties of local holomorphic gauge invariant collective fields in the Hamiltonian formulation of YM_{2+1}. We show that the spectrum in the

R. F. Sawyer

We study some examples of collective behavior in neutrino clouds governed by the neutral-current neutrino-neutrino interaction. The standard equations for analyzing such systems are rederived in a two-step process: first, a replacement of the full interaction Hamiltonian with a &#34;forward&#34; Hamiltonian that contains only the momentum states that were in

J. Arrington

Significant discrepancies have been observed between proton form factors as measured by Rosenbluth separation and polarization transfer techniques. There are indications that this difference may be caused by corrections to the one photon exchange approximation that are not taken into account in standard radiative correction procedures. In this paper, we cons