December 2005 arXiv papers — page 14

David J. Hemmer

Recently Donkin defined signed Young modules as a simultaneous generalization of Young and twisted Young modules for the symmetric group. We show that in odd characteristic, if a Specht module $S^λ$ is irreducible, then $S^λ$ is a signed Young module. Thus the set of irreducible Specht modules coincides with the set of irreducible signed Young modules. This

Gastao S. F. Frederico, Delfim F. M. Torres

We extend Noether's theorem to dynamical optimal control systems being under the action of nonconservative forces. A systematic way of calculating conservation laws for nonconservative optimal control problems is given. As a corollary, the conserved quantities previously obtained in the literature for nonconservative problems of mechanics and the calculu

Philippe Biane

We give a simple proof of an explicit formula for Kerov polynomials. This formula is closely related to a formula of Goulden and Rattan.

Martin Grothaus, Yuri G. Kondratiev, Michael Röckner

We provide an $N/V$-limit for the infinite particle, infinite volume stochastic dynamics associated with Gibbs states in continuous particle systems on $\mathbb R^d$, $d \ge 1$. Starting point is an $N$-particle stochastic dynamic with singular interaction and reflecting boundary condition in a subset $Λ\subset {\mathbb R}^d$ with finite volume (Lebesgue mea

Michael Röckner, Feng-Yu Wang, Liming Wu

The large deviation principle is established for the distributions of a class of generalized stochastic porous media equations for both small noise and short time.

Sergio Albeverio, Yuri G. Kondratiev, Tatiana Pasurek, Michael Röckner

We prove a priori estimates and, as sequel, existence of Euclidean Gibbs states for quantum lattice systems. For this purpose we develop a new analytical approach, the main tools of which are: first, a characterization of the Gibbs states in terms of their Radon-Nikodym derivatives under shift transformations as well as in terms of their logarithmic derivati

S. Herr

It is shown that the Cauchy problem for the DNLS equation in the spatially periodic setting is locally well-posed in Sobolev spaces H^s(T) for s \geq 1/2. Moreover, global well-posedness is shown for s \geq 1 and data with small L^2 norm.

A. Borichev, R. Chill, Yu. Tomilov

We obtain uniqueness theorems for harmonic and subharmonic functions of a new type. They lead to new analytic extension criteria and new conditions for stability of operator semigroups in Banach spaces with Fourier type.

H. Gopalkrishna Gadiyar, R. Padma

It is noted that an efficient algorithm for calculating a $p$-adic height could have cryptanalytic applications.

Stefano Serra Capizzano

multiplication operator on a Hilbert space may be approximated with finite sections by choosing an orthonormal basis of the Hilbert space. Nonzero multiplication operators on $L^2$ spaces of functions are never compact and then such approximations cannot converge in the norm topology. Instead, we consider how well the spectra of the finite sections approxima

Pooja Singla

Let $I$ be a monomial ideal in a polynomial ring $A=K[x_1,...,x_n]$. We call a monomial ideal $J$ to be a minimal monomial reduction ideal of $I$ if there exists no proper monomial ideal $L \subset J$ such that $L$ is a reduction ideal of $I$. We prove that there exists a unique minimal monomial reduction ideal $J$ of $I$ and we show that the maximum degree

Nicolas Lerner

For a principal type pseudodifferential operator, we prove that condition (psi) implies local solvability with a loss of 3/2 derivatives. We use many elements of Dencker's paper on the proof of the Nirenberg-Treves conjecture and we provide some improvements of the key energy estimates which allows us to cut the loss of derivatives from 2 (Dencker's

M-T. Benameur, A. L. Carey, J. Phillips, A. Rennie

The analytic approach to spectral flow is about ten years old. In that time it has evolved to cover an ever wider range of examples. The most critical extension was to replace Fredholm operators in the classical sense by Breuer-Fredholm operators in a semifinite von Neumann algebra. The first part of this paper gives a brief account of this theory extending

Ettore Aldrovandi

We define 2-gerbes bound by complexes of braided group-like stacks. We prove a classification result in terms of hypercohomology groups with values in abelian crossed squares and cones of morphisms of complexes of length 3. We give an application to the geometric construction of certain elements in Hermitian Deligne cohomology groups.

Alice Chang, Jie Qing, Paul Yang

We study the renormalized volume of a conformally compact Einstein manifold. In even dimensions, we derive the analogue of the Chern-Gauss-Bonnet formula incorporating the renormalized volume. When the dimension is odd, we relate the renormalized volume to the conformal primitive of the $Q$-curvature. We show how all the global information come from the Scat

Harm Derksen, Aidan Schofield, Jerzy Weyman

It is well-known that the intersection multiplicities of Schubert classes in the Grassmanian are Littlewood-Richardson coefficients. We generalize this statement in the context of quiver representations. Here the intersection multiplicity of Schubert classes is replaced by the number of subrepresentations of a general quiver reprsentation, and the Littlewood

Bogdan Bojarski, Andrzej Weber

We define certain class of correspondences of polarized representations of $C^*$-algebras. Our correspondences are modeled on the spaces of boundary values of elliptic operators on bordisms joining two manifolds. In this setup we define the index. The main subject of the paper is the additivity of the index.

Maxim Braverman, Thomas Kappeler

For an acyclic representation of the fundamental group of a compact oriented odd-dimensional manifold, which is close enough to a unitary representation, we define a refinement of the Ray-Singer torsion associated to this representation. This new invariant can be viewed as an analytic counterpart of the refined combinatorial torsion introduced by Turaev. The

Thorsten Theobald

We study some basic algorithmic problems concerning the intersection of tropical hypersurfaces in general dimension: deciding whether this intersection is nonempty, whether it is a tropical variety, and whether it is connected, as well as counting the number of connected components. We characterize the borderline between tractable and hard computations by pr

Pablo Mora

In this work I consider extensions of Chern-Simons gravities and supergravities associated to the use of Transgression forms as actions, instead of Chern-Simons forms. It is noted that Transgression Forms yields a essencially unique prescription of boundary terms which allows: (i) to make Chern-Simons theories truly gauge invariant, instead of just quasi-inv

P. Marios Petropoulos, Konstadinos Sfetsos

We consider NS5-branes distributed along the circumference of an ellipsis and explicitly construct the corresponding gravitational background. This provides a continuous line of deformations between the limiting cases, considered before, in which the ellipsis degenerates into a circle or into a bar. We show that a slight deformation of the background corresp

Graciela B. Gelmini

"GZK photons" are produced by extragalactic nucleons through the resonant photoproduction of pions. We present the expected range of the GZK photon fraction of UHECR, assuming a particular UHECR spectrum and primary nucleons, and compare it with the minimal photon fraction predicted by Top-Down models.

Graciela B. Gelmini

We show that the annual modulation signal observed by DAMA can be reconciled with all other negative results from dark matter searches with a conventional halo model for particle masses around 5 to 9 GeV. We also show which particular dark matter stream could produce the DAMA signal.

Johann Rafelski, Jean Letessier

We discuss how the dynamics of the evolving hot fireball of quark--gluon matter impacts phase transition between the deconfined and confined state of matter. The rapid expansion of the fireball of deconfined matter created in heavy ion collisions facilitates formation of an over-saturated strange quark phase space. The related excess abundance of strangeness

Hans Volker Klapdor-Kleingrothaus

The occurrence of the neutrinoless decay 0n-bb mode has fundamental consequences: first total lepton number is not conserved, and second, the neutrino is a Majorana particle. Further the effective mass measured allows to put an absolute scale of the neutrino mass spectrum. In addition, double beta experiments yield sharp restrictions also for other beyond st

U. Baur, A. Juste, D. Rainwater, L. H. Orr

We consider QCD tt~Z production at the LHC with Z->\barννand all-hadronic tt~ decays, i.e. pp -> p_T(miss)bb~+4 jets, as a tool to measure ttZ couplings. This channel has a significantly larger cross section than those where the Z boson decays leptonically. However, tt~, bb~+4 jet, tt~j and tt~jj production give rise to potentially large backgrounds. We show

R. Fiore, L. L. Jenkovszky, A. V. Kotikov, F. Paccanoni

In this paper we present a simple analytic expression for the (spin-averaged) neutrino-nucleon cross section for ultra-high energies at twist-2, obtained as the asymptotic limit of our previous findings. This expression gives values for the cross section in remarkable numerical agreement with the previous numerical evaluation in the energy region relevant fo

M. Beneke, J. Rohrer, D. Yang

We discuss a novel electromagnetic penguin contribution to the transverse helicity amplitudes in B decays to two vector mesons, which is enhanced by two powers of mB/Lambda relative to the standard penguin amplitudes. This leads to unique polarization signatures in penguin-dominated decay modes such as B-->rho K* similar to polarization effects in the radiat

M. Klasen

When comparing recent experimental data from the H1 and ZEUS Collaborations at HERA for diffractive dijet production in deep-inelastic scattering (DIS) and photoproduction with next-to-leading order (NLO) QCD predictions using diffractive parton densities, good agreement is found for DIS. However, the dijet photoproduction data are overestimated by the NLO t

Robert Fleischer

The exploration of the quark-flavour sector of the Standard Model is one of the hot topics in particle physics of this decade. In these studies, which show a fruitful interplay between theory and experiment, the B-meson system offers a particularly interesting laboratory. After giving an introduction to quark-flavour mixing and CP violation as well as to the

Anjan S. Joshipura

Possible maximal mixing seen in the oscillations of the atmospheric neutrinos has led to postulate of a $μ$-$τ$ symmetry which interchanges $ν_μ$ and $ν_τ$. We argue that such symmetry need not be special to neutrinos but can be extended to all fermions. The assumption that all fermion mass matrices are approximately invariant under interchange of the second

Matteo Cacciari

We present up-to-date QCD predictions for open charm and bottom production at RHIC in nucleon-nucleon collisions at \sqrt{S} = 200 GeV. The electron spectrum resulting from heavy flavor decays is also evaluated for direct comparison to the PHENIX and STAR data. These predictions seek to establish a rigorous benchmark, including the theoretical uncertainties,

A. Bialas, K. Zalewski

Coincidence probabilities, which yield Renyi entropies, are investigated in a generalized Gaussian model, which includes interparticle correlations

A. Juste

A precise measurement of the top quark Yukawa coupling is of great importance, since it may shed light on the mechanism of EWSB. We study the prospects of such measurement during the first phase of the ILC at sqrt(s)=500 GeV, focusing in particular on recent theoretical developments as well as the potential benefits of beam polarization. It is shown that bot

Zs. Szep

Incorporating its most relevant global symmetry, chiral effective models are aimed at investigating, in a simplified framework, important aspects of the yet unsolved QCD. We review some recent results obtained in these models on the restoration of chiral and axial symmetries, on the boundary of the first order phase transition region in the m_pi-m_K-plane at

Antonio M. Garcia-Garcia, James C. Osborn

We study the spectrum and eigenmodes of the QCD Dirac operator in a gauge background given by an Instanton Liquid Model (ILM) at temperatures around the chiral phase transition. Generically we find the Dirac eigenvectors become more localized as the temperature is increased. At the chiral phase transition, both the low lying eigenmodes and the spectrum of th

Yongsheng Gao

We present some recent results in hadronic decays and cross-section measurements at Psi(3770) from CLEO collaboration. They include measurement of absolute hadronic branching fractions of D mesons and e+e- to DDbar cross-sections, inclusive production of eta, eta', phi in D decays, branching fractions of D+ to K0_{S,L} pi+ and eta pi+, Psi(3770) non-DDba

A. Bevan

B-meson decays involving b->u transitions are sensitive to the Unitarity Triangle angle alpha (or phi_2). The B-factories at SLAC and KEK have made significant progress toward the measurement of alpha in recent years. This paper summarizes the results of the B-factories' constraints on alpha.

Yongsheng Gao

We report improved measurements of branching fraction and decay constant fD+ in D+ to mu+nu using 281 pb-1 of data taken on the Psi(3770) resonance with the CLEO-c detector. We extract a relatively precise value for the decay constant of the D+ meson by measuring Br(D+ to mu+nu) = (4.40+-0.66+0.09-0.12)x10^-4 and find fD+ = (222.6+-16.7+2.8-3.4) MeV. We also

P. T. Chrusciel, H. S. Reall, P. Tod

We show, under certain conditions, that regular Israel-Wilson-Perjés black holes necessarily belong to the Majumdar-Papapetrou family.

F. Rahaman, P. Ghosh, M. Kalam, S. Mandal

We study the gravitational properties of a global monopole in $(D = d + 2)$ dimensional space-time in presence of electromagnetic field.

F. Rahaman, B. C. Bhui, P. Ghosh

It is well known that a C-field, generated by a certain source equation leads to interesting changes in the cosmological solutions of Einstein's equations. In this article we present and analyze a simple Lorentzian vacuum wormhole in the presence of C-field.

Lorenzo Iorio

In this paper we investigate the possibility of measuring the general relativistic gravitoelectric contribution P^(GE) to the orbital period P of the transiting exoplanet HD 209458b 'Osiris'. It turns out that the predicted magnitude of such an effect is \sim 0.1 s, while the most recent determinations of the orbital period of HD 209458b with the pho

Erik D. Demaine, Friedhelm Meyer auf der Heide, Rasmus Pagh, Mihai Patrascu

We develop dynamic dictionaries on the word RAM that use asymptotically optimal space, up to constant factors, subject to insertions and deletions, and subject to supporting perfect-hashing queries and/or membership queries, each operation in constant time with high probability. When supporting only membership queries, we attain the optimal space bound of Th

G. B. Pivovarov, S. E. Trunov

Time evolution of the classification scheme generated by the EqRank algorithm is studied with hep-th citation graph as an example. Intuitive expectations about evolution of an adequate classification scheme for a growing set of objects are formulated. Evolution compliant with these expectations is called natural. It is demonstrated that EqRank yields a natur

Eirik Fossgaard

We develop a code length principle which is invariant to the choice of parameterization on the model distributions. An invariant approximation formula for easy computation of the marginal distribution is provided for gaussian likelihood models. We provide invariant estimators of the model parameters and formulate conditions under which these estimators are e

Pascal O. Vontobel, Ralf Koetter

The goal of the present paper is the derivation of a framework for the finite-length analysis of message-passing iterative decoding of low-density parity-check codes. To this end we introduce the concept of graph-cover decoding. Whereas in maximum-likelihood decoding all codewords in a code are competing to be the best explanation of the received vector, und

Matthias Braun, Jürgen König, Jan Martinek

We discuss the possibility to generate, manipulate, and probe single spins in single-level quantum dots coupled to ferromagnetic leads. The spin-polarized currents flowing between dot and leads lead to a non-equilibrium spin accumulation, i.e., a finite polarization of the dot spin. Both the magnitude and the direction of the dot's spin polarization depe

Bartosz Rozycki, Reinhard Lipowsky, Thomas R. Weikl

We consider a theoretical model for membranes with adhesive receptors, or stickers, that are actively switched between two conformational states. In their 'on'-state, the stickers bind to ligands in an apposing membrane, whereas they do not interact with the ligands in their 'off'-state. We show that the adhesiveness of the membranes depends

B. B. Levchenko

Several parameterizations of tabulated values of the Nordheim function $\vartheta (y)$ and its complementary function $t(y)$ are proposed. The function $\vartheta (y)$ plays essential role in description of field emission.

A. K. Zhuravlev, V. Yu. Irkhin, M. I. Katsnelson

Using numerical renormalization group method the temperature dependences of the magnetic susceptibility $χ(T)$ and specific heat $C(T)$ are obtained in the single-impurity Anderson model with inclusion of the $d-f$ Coulomb interaction. It is shown that the exciton effects owing to this interaction can change considerably the dependence $C(T)$ in comparison w

C. Vignat, A. Plastino, A. R. Plastino

We show, on purely statistical grounds and without appeal to any physical model, that a power-law $q-$entropy $S_q$, with $0<q<1$, can be {\it extensive}. More specifically, if the components $X_i$ of a vector $X \in \mathbb{R}^N$ are distributed according to a Gaussian probability distribution $f$, the associated entropy $S_q(X)$ exhibits the extensivity pr

P. Adler, A. Lebon, V. Damljanovic, C. Ulrich

Single crystals of iron(IV) rich oxides SrFeO(3-x) with controlled oxygen content have been studied by Moessbauer spectroscopy, magnetometry, magnetotransport measurements, Raman spectroscopy, and infrared ellipsometry in order to relate the large magnetoresistance (MR) effects in this system to phase composition, magnetic and charge order. It is shown that

Yunkyu Bang, Matthias J. Graf, Nicholas J. Curro, Alexander V. Balatsky

We calculated the Knight shift and spin-lattice relaxation rates of Pu-115 compounds assuming d-wave superconductivity in the presence of strong impurity scattering. We discuss the implications for recent measurements of the spin-lattice relaxation rate in the Pu-115 compound PuRhGa5 by Sakai and coworkers [J. Phys. Soc. Jpn. 74, 1710 (2005)] and present a p

O. Parcollet, X. Waintal

We present a complete theory of the spin torque phenomena in a ultrasmall nanomagnet coupled to non-collinear ferromagnetic electrodes through tunnelling junctions. This model system can be described by a simple microscopic model which captures many physical effects characteristic of spintronics: tunneling magneto resistance, intrinsic and transport induced

C. H. Wang, X. H. Chen, T. Wu, X. G. Luo

The magnetic and transport properties are systematically studied on the single crystal $Na_{0.55}CoO_2$ with charge ordering and divergency in resistivity below 50 K. A long-range ferromagnetic ordering is observed in susceptibility below 20 K with the magnetic field parallel to Co-O plane, while a negligible behavior is observed with the field perpendicular

S. Bargi, G. M. Kavoulakis, S. M. Reimann

We consider bosonic atoms that rotate in an anharmonic trapping potential. Using numerical diagonalization of the Hamiltonian, we identify the various phases of the gas as the rotational frequency of the trap and the coupling between the atoms are varied.

V. Marigliano Ramaglia, V. Cataudella, G. De Filippis, C. A. Perroni

We discuss the combined effect of Rashba and Dresselhaus spin-orbit interactions in polygonal loops formed by quantum wires, when the electron are injected in a node and collected at the opposite one. The conditions that allow perfect localization are found. Furthermore, we investigate the suppression of the Al&#39;tshuler--Aronov--Spivak oscillations that a

F. Tasnadi

Bertaut&#39;s equivalent electric density idea (E. F. Bertaut, Journal de Physique {\bf 39}, 1331 (1978)) is applied to the case of two dimensional periodic continuous charge density distributions. The following derivation differs from what was introduced by Bertaut. The presented method solves the Poisson equation for the scheme of overlapping localized sit

Daniele Moroni, Benjamin Rotenberg, Jean-Pierre Hansen, Sauro Succi

We propose a discrete lattice version of the Fokker-Planck kinetic equation along lines similar to the Lattice-Boltzmann scheme. Our work extends an earlier one-dimensional formulation to arbitrary spatial dimension $D$. A generalized Hermite-Gauss procedure is used to construct a discretized kinetic equation and a Chapman-Enskog expansion is applied to adap

S. I. Vedeneev, D. K. Maude

The in-plane $ρ_{ab}(H,T)$ and the out-of-plane $ρ_c(H,T)$ magneto-transport in magnetic fields up to 28 T has been investigated in high quality non-superconducting (down to 20 mK) La-free Bi$_{2+x}$Sr$_{2-x}$CuO$_{6+δ}$ single crystal. By measuring the angular dependence of the in-plane and out-of-plane magnetoresistivities at temperatures from 1 K down to

S. Sarkar, A. D. Thakur, C. V. Tomy, G. Balakrishnan

New experimental data are presented on the scan rate dependence of the magnetization hysteresis width $ΔM(H)$ ($\propto$ critical current density $J_c(H)$) in isothermal $M-H$ scans in a weakly pinned single crystal of Ca$_3$Rh$_4$Sn$_{13}$, which displays second magnetization peak (SMP) anomaly as distinct from the peak effect (PE). We observe an interestin

L. Seetha Lakshmi, V. Sridharan, R. Rawat, A. A. Sukumar

In this paper, we examine the possible influence of extrinsic factors on the electrical and magnetotransport of La(0.67)Ca(0.33)Mn(1-x)Ru(x)O(3) (x < 0.10). These results not only exclude the extrinsic factors, but establishes the fact that the metal transitions both exhibiting MR is intrinsic to Ru substituted La(0.67)Ca(0.33)MnO(3) and the system. These re

M. T. Batchelor, M. Bortz, X. W. Guan, N. Oelkers

We investigate the elementary excitations of charge and spin degrees for the 1D interacting two-component Bose and Fermi gases by means of the discrete Bethe ansatz equations. Analytic results in the limiting cases of strong and weak interactions are derived, where the Bosons are treated in the repulsive and the fermions in the strongly attractive regime. We

Yan-Bo Xie, Tao Zhou, Bing-Hong Wang

In this letter, we proposed an ungrowing scale-free network model, wherein the total number of nodes is fixed and the evolution of network structure is driven by a rewiring process only. In spite of the idiographic form of $G$, by using a two-order master equation, we obtain the analytic solution of degree distribution in stable state of the network evolutio

Monika Sprenger, Frank Schlesener, S. Dietrich

We consider binary liquid mixtures close to their critical points confined by two parallel, geometrically flat but chemically structured, substrates. Universal order parameters profiles are calculated within mean field theory for periodic patterns of stripes with alternating preferences for the two species of the mixture and with different relative positions

Jan de Gier, Fabian H. L. Essler

We derive the Bethe ansatz equations describing the complete spectrum of the transition matrix of the partially asymmetric exclusion process with the most general open boundary conditions. For totally asymmetric diffusion we calculate the spectral gap, which characterizes the approach to stationarity at large times. We observe boundary induced crossovers in

J. M. P. Carmelo, K. Penc

We show that the pre-factors of all terms of the one-dimensional Hubbard model correlation-function asymptotic expansions have an universal form, as the corresponding critical exponents. In addition to calculating such pre-factors, our study clarifies the relation of the low-energy Tomonaga-Luttinger liquid behavior to the scattering mechanisms which control

Qimiao Si, Jian-Xin Zhu, D. R. Grempel

The identification of magnetic quantum critical points in heavy fermion metals has provided an ideal setting for experimentally studying quantum criticality. Motivated by these experiments, considerable theoretical efforts have recently been devoted to reexamine the interplay between Kondo screening and magnetic interactions in Kondo lattice systems. A local

Maxim G. Vavilov, A. Douglas Stone

We study the effect of mesoscopic fluctuations on the validity of the Wiedemann--Franz (WF) law for quasi-one-dimensional metal wires and open quantum dots. At temperatures much less than the generalized Thouless energy, E_c, the WF law is satisfied for each specific sample but as the temperature is raised through E_c a sample-specific correction to the WF l

Shin-ichi Sasa, Hal Tasaki

The present paper reports our attempt to search for a new universal framework in nonequilibrium physics. We propose a thermodynamic formalism that is expected to apply to a large class of nonequilibrium steady states including a heat conducting fluid, a sheared fluid, and an electrically conducting fluid. We call our theory steady state thermodynamics (SST)

J. M. P. Carmelo, K. Penc

We introduce a method that allows the evaluation of general expressions for the spectral functions of the one-dimensional Hubbard model for all values of the on-site electronic repulsion U. The spectral weights are expressed in terms of pseudofermion operators such that the spectral functions can be written as a convolution of pseudofermion dynamical correla

Laurent Chemin, Olivier Hernandez, Chantal Balkowski, Claude Carignan

The ionized gas kinematics of the Virgo Cluster galaxy NGC 4254 (Messier 99) is analyzed by an harmonic decomposition of the velocity field into Fourier coefficients. The aims of this study are to measure the kinematical asymmetries of Virgo cluster galaxies and to connect them to the environment. The analysis reveals significant $m=1,2,4$ terms which origin

Jes Madsen

Stable lumps of quark matter may be present in cosmic rays at a flux level, which can be detected by high precision cosmic ray experiments sensitive to anomalous &#34;nuclei&#34; with high mass-to-charge ratio. The properties of these lumps, called strangelets, are described, and so is the production and propagation of strangelets in cosmic rays. Two experim

J. F. Gonzalez, S. Hubrig, N. Nesvacil, P. North

Using recent spectroscopic observations, we show that the triple system AO Vel with an eclipsing BpSi primary is in fact a remarkable quadruple system formed by two double-lined spectroscopic binaries with components close to the ZAMS. All available data have been reanalyzed to derive proper orbital parameters for both binary systems and to calculate absolut

A. Sozzetti, D. Yong, B. W. Carney, J. B. Laird

We present a detailed chemical abundance analysis of the parent star of the transiting extrasolar planet TrES-1. Based on high-resolution Keck/HIRES and HET/HRS spectra, we have determined abundances relative to the Sun for 16 elements (Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Y, and Ba). The resulting average abundance of $<[$$X$/H$]>$ $= -0.0

Stephan R. Bjork, Brian Chaboyer

A Monte Carlo simulation exploring uncertainties in standard stellar evolution theory on the red giant branch of metal-poor globular clusters has been conducted. Confidence limits are derived on the absolute V-band magnitude of the bump in the red giant branch luminosity function (M_v,b) and the excess number of stars in thebump, R_b. The analysis takes into

Jorge Penarrubia, Andrew J. Benson, David Martinez-Delgado, Hans-Walter Rix

We explore whether stellar tidal streams can provide information on the secular, cosmological evolution of the Milky Way&#39;s gravitational potential and on the presence of subhalos. We carry out long-term (~t_hubble) N-body simulations of disrupting satellite galaxies in a semi-analytic Galaxy potential where the dark matter halo and the subhalos evolve ac

S. Borgani, K. Dolag, G. Murante, L. -M. Cheng

We discuss an extended set of Tree+SPH simulations of galaxy clusters, with the goal of investigating the interplay between numerical resolution effects and star-formation/feedback processes. The simulated clusters span the mass range (0.1-2.3) 10^{15}Msun/h, with mass resolution varying by several decades. At the highest achieved resolution, we resolve the

Bacham E. Reddy, David L. Lambert, Carlos Allende Prieto

[Abridged abstract] We have performed an abundance analysis for 176 F- and G- dwarfs of the Galactic thick disk component. Using accurate radial velocities combined with $Hipparcos$ astrometry, kinematics (U, V, and W) and Galactic orbital parameters were computed. We estimate the probability for a star to belong to the thin disk, the thick disk or the halo.

Petro F. Lazorenko

In this paper we test the astrometric precision of VLT/FORS2 observations using a serie of CCD frames taken in Galactic bulge area. A special reduction method based on symmetrization of reference fields was used to reduce the atmospheric image motion. Positional precision of unsaturated R=16 mag star images at 17 sec exposure and 0.55 arcsec seeing was found

M. Tafalla

Our understanding of the physical and chemical structure of pre-stellar cores, the simplest star-forming sites, has significantly improved since the last IAU Symposium on Astrochemistry (South Korea, 1999). Research done over these years has revealed that major molecular species like CO and CS systematically deplete onto dust grains at the interior of pre-st

R. G. Carlberg

IAU Symposium 232 allows a snapshot of ELTs at a stage when design work in several critical mass projects has been seriously underway for two to three years. The status and som eof the main initial design choices are reviewed for the North American Giant Magellan Telescope (GMT) and the Thirty Meter Telescope (TMT) projects and the European Euro50 and the Ov

Christopher J. Conselice

Recent observations demonstrate that dwarf elliptical (dE) galaxies in clusters, despite their faintness, are likely a critical galaxy type for understanding the processes behind galaxy formation. Dwarf ellipticals are the most common galaxy type, and are particularly abundant in rich galaxy clusters. The dwarf to giant ratio is in fact highest in rich clust

Q. R. Chen, M. D. Ding

We present observations of the 2002 September 30 white-light flare, in which the optical continuum emission near the Halpha line is enhanced by ~10%. The continuum emission exhibits a close temporal and spatial coincidence with the hard X-ray (HXR) footpoint observed by RHESSI. We find a systematic motion of the flare footpoint seen in the continuum emission

Elena M. Rossi, Andrei M. Beloborodov, Martin J. Rees

Relativistic neutron-loaded outflows in gamma-ray bursts are studied at their early stages, before deceleration by a surrounding medium. The outflow has four components: radiation, electrons, protons and neutrons. The components interact with each other and exchange energy as the outflow expands. The presence of neutrons significantly changes the outflow evo

Supratik Pal

An alternative way of explaining astrophysical observations without dark matter is proposed. In the braneworld scenario, where our universe is visualised as a 4-dimensional hypersurface embedded in a higher dimensional spacetime, the effective Einstein equation on the brane contains extra terms. We show that the astrophysical observations which are usually e

Chen-zhou Cui, Markus Dolensky, Peter Quinn, Yong-heng Zhao

VOFilter is an XML based filter developed by the Chinese Virtual Observatory project to transform tabular data files from VOTable format into OpenDocument format. VOTable is an XML format defined for the exchange of tabular data in the context of the Virtual Observatory (VO). It is the first Proposed Recommendation defined by International Virtual Observator

D. Garcia-Alvarez, J. J. Drake, B. Ball, L. Lin

$β$ Cet, 31 Com and $μ$ Vel represent the main stages through which late-type giants evolve during their lifetime (the Hertzsprung gap (31 Com), the rapid braking zone ($μ$ Vel) and the core helium burning ``clump&#39;&#39; phase ($β$ Cet)). An analysis of their high resolution {\it Chandra} X-ray spectra reveals similar coronal characteristics in terms of b

R. -F. Shen, P. Kumar, E. L. Robinson

The Gamma-Ray Burst (GRB) prompt emission is believed to be from highly relativistic electrons accelerated in relativistic shocks. From the GRB high-energy power-law spectral indices $β$ observed by the Burst and Transient Source Experiment (BATSE) Large Area Detectors (LAD), we determine the spectral index, $p$, of the electrons&#39; energy distribution. Bo

Johannes Hirn, Nuria Rius, Veronica Sanz

An SU(Nf)xSU(Nf) Yang-Mills theory on an extra-dimensional interval is considered, with appropriate symmetry-breaking boundary conditions on the IR brane. UV-brane to UV-brane correlators at high energies are compared with the OPE of two-point functions of QCD quark currents. Condensates correspond to departure from AdS of the (different) metrics felt by vec

A. Achucarro, P. Salmi, J. Urrestilla

We report on a large scale numerical study of networks of semilocal cosmic strings in flat space in the parameter regime in which they are perturbatively stable. We find a population of segments with an exponential length distribution and indications of a scaling network without significant loop formation. Very deep in the stability regime strings of superho

P. T. Chrusciel, E. Delay

We construct infinite dimensional families of non-singular stationary space times, solutions of the vacuum Einstein equations with a negative cosmological constant.

Gino N. J Ananos

We discuss the $ϕ^6 $ theory defined in $D=2+1$-dimensional space-time and assume that the system is in equilibrium with a thermal bath at temperature $β^{-1}$. We use the $ 1/N $ expansion and the method of the composite operator (CJT) for summing a large set of Feynman graphs.We demonstrate explicitly the Coleman-Mermin-Wagner theorem at finite temperature

N. M. R. Peres, A. H. Castro Neto, F. Guinea

Using a generalized Landauer approach we study the non-linear transport in mesoscopic graphene with zig-zag and armchair edges. We find that for clean systems, the low-bias low-temperature conductance, G, of an armchair edge system in quantized as G/t=4 n e^2/h, whereas for a zig-zag edge the quantization changes to G/t t=4(n+1/2)e^2/h, where t is the transm

F. Karsch, D. Kharzeev, H. Satz

Finite temperature lattice QCD indicates that the charmonium ground state J/psi can survive in a quark-gluon plasma up to 1.5 T_c or more, while the excited states chi_c and psi-prime are dissociated just above T_c. We assume that the chi_c suffers the same form of suppression as that observed for the psi-prime in SPS experiments, and that the directly produ

Stephen C. Anco

Moving frames of various kinds are used to derive bi-Hamiltonian operators and associated hierarchies of multi-component soliton equations from group-invariant flows of non-stretching curves in constant curvature manifolds and Lie group manifolds. The hierarchy in the constant-curvature case consists of a vector mKdV equation coming from a parallel frame, a

Stephen C. Anco

The bi-Hamiltonian structure of the two known vector generalizations of the mKdV hierarchy of soliton equations is derived in a geometrical fashion from flows of non-stretching curves in Riemannian symmetric spaces G/SO(N). These spaces are exhausted by the Lie groups G=SO(N+1),SU(N). The derivation of the bi-Hamiltonian structure uses a parallel frame and c

Bout Marcelis, Servaas Kokkelmans

Superfluidity in an ultracold Fermi gas is usually associated with either a negative scattering length, or the presence of a two-body bound state. We show that none of these ingredients is necessary to achieve superfluidity. Using a narrow Feshbach resonance with strong repulsive background interactions, the effective interactions can be repulsive for small

Philip W Anderson

The puzzling &#34;strange metal&#34; phase of the high Tc cuprate phase diagram reveals itself as closer to a Fermi liquid than previously supposed: it is a consequence of Gutzwiller projection and does not necessarily require exotica such as an RVB or mysterious quantum critical points. There is a Fermi liquid-like excitation spectrum but the excitations ar