April 2003 arXiv papers — page 3

W. Neubert, A. S. Botvina

Experimental data related to fragment production in central Au on Au collisions were analyzed in the framework of a modified statistical model which considers cluster production both prior and at the equilibrated stage. The analysis provides limits to the number of nucleons and to the temperature of the equilibrated source. The rather moderate temperatures o

A. A. Rukhadze, L. I. Urutskojev, D. V. Filippov

The official conclusion about the origin and mechanism of the Chernobyl catastrophe is shown to essentially contradict experimental facts available from the accident. In the frame of existing physical models of nuclear fission reactor, it is shown analytically that under conditions of the accident the period of runaway of reactor at the fourth power generati

A. Belafrites, A. Boucenna, C. Benazzouz, M. A. Benammar

The determination of the mean lifetime of excited states has been undertaken by coulomb excitation that is a process of inelastic scattering in which the incident particle is charged and provokes an excitation of the target nucleus by mean of the electromagnetic fields during the passage of the projectile. The cross section of this inelastic scattering is pr

Daniele Fournier-Prunaret, Ricardo Lopez-Ruiz

Previous works have been devoted to the study of two-dimensional noninvertible maps, obtained using a coupling between one-dimensional logistic maps. This paper is devoted to the study of a specific one, in order to complete previous results (Ref. 5 and 7), regarding the evolution of basins and attractors, when considering the tool of critical manifolds.

Michael Kastner

Discrete breathers are time-periodic, spatially localized solutions of the equations of motion for a system of classical degrees of freedom interacting on a lattice. An important issue, not only from a theoretical point of view but also for their experimental detection, are their energy properties. We considerably enlarge the scenario of possible energy prop

Gianfranco Capriz, Paolo Maria Mariano

Preliminary results toward the analysis of the Hamiltonian structure of multifield theories describing complex materials are mustered: we involve the invariance under the action of a general Lie group of the balance of substructural interactions. Poisson brackets are also introduced in the material representation to account for general material substructures

Oleg I. Morozov

The moving coframe method is applied to solve the local equivalence problem for the class of linear parabolic equations in two independent variables under an action of the pseudo-group of contact transformations. The structure equations and the complete sets of differential invariants for symmetry groups are found. The solution of the equivalence problem is

Simon Kristensen

We characterise the set of periods for which number theoretical obstructions prevent us from finding periodic solutions of the Schroedinger equation on a two dimensional torus as well as the asymptotic occurrence of possible resonances.

Pierre Sleewaegen

A generalized moment map is proposed for arbitrary symplectic actions of compact connected Lie groups on closed symplectic manifolds, in the spirit of the circle -valued maps introduced by D. McDuff in the case of non-Hamiltonian circle actions. We study equivariance properties of generalized moments, show that they allow reduction procedures, and obtain in

C. Faber, R. Pandharipande

The moduli space of stable relative maps to the projective line combines features of stable maps and admissible covers. We prove all standard Gromov-Witten classes on these moduli spaces of stable relative maps have tautological push-forwards to the moduli space of curves. In particular, the fundamental classes of all moduli spaces of admissible covers push-

R. M. Green

Heaps of pieces were introduced by Viennot and have applications to algebraic combinatorics, theoretical computer science and statistical physics. In this paper, we how certain combinatorial properties of heaps studied by Fan and by Stembridge are closely related to the properties of a certain linear map $\partial_E$ associated to a heap $E$. We examine the

Lenny Taelman

We observe that the Dieudonné determinant induces a non-negative degree function on the ring of matrices over a skew polynomial ring. We then apply this degree function to two examples. In the first one, we find an expression for the rank of the kernel of an endomorphism of the algebraic group $\mathbb{G}_a^n$ over a field of characteristic $p>0$. In the sec

Jeffrey Shallit

In 1976, Dekking showed that there exists an infinite binary word that contains neither squares yy with y >= 4 nor cubes xxx. We show that `cube' can be replaced by any fractional power > 5/2. We also consider the analogous problem where `4' is replaced by any integer. This results in an interesting and subtle hierarchy.

David Kerr

A basic problem in dynamics is to identify systems with positive entropy, i.e., systems which are "chaotic." While there is a vast collection of results addressing this issue in topological dynamics, the phenomenon of positive entropy remains by and large a mystery within the broader noncommutative domain of C*-algebraic dynamics. To shed some light

Takeshi Suzuki

We study a class of representations over the degenerate double affine Hecke algebra of gl_n by an algebraic method. As fundamental objects in this class, we introduce certain induced modules and study some of their properties. In particular, it is shown that these induced modules have unique simple quotient modules under certain conditions. Moreover, we show

Luis Dieulefait, Jayanta Manoharmayum

We prove modularity for a huge class of rigid Calabi-Yau threefolds over $\Q$. In particular we prove that every rigid Calabi-Yau threefold with good reduction at 3 and 7 is modular.

Leonardo Biliotti

In this paper we will investigate the global properties of complete Hilbert manifolds with upper and lower bounded sectional curvature. We shall prove the Focal Index Lemma that we will allow us to extend some classical results of finite dimensional Riemannian geometry such as Rauch and Berger Theorems and the Topogonov Theorem in the class of manifolds on w

Geoffrey Mason, Siu-Hung Ng

In this paper, we obtain a canonical central element $ν_H$ for each semi-simple quasi-Hopf algebra $H$ over any field $k$ and prove that $ν_H$ is invariant under gauge transformations. We show that if $k$ is algebraically closed of characteristic zero then for any irreducible representation of $H$ which affords the character $χ$, $χ(ν_H)$ takes only the valu

Jeremy Quastel

We consider inhomogeneous Bernoulli measures of the form $\prod_{x\inΛ} p_x$ where $p_x$ are prescribed and uniformly bounded above and below away from 0 and 1. A comparison inequality is proved between the Kawasaki and Bernoulli-Laplace Dirichlet forms. Together with a recent result of Caputo on the gap of the Bernoulli-Laplace model, this proves a spectral

Laurent Buse, David Cox, Carlos D'Andrea

We show that the method of moving quadrics for implicitizing surfaces in P^3 applies in certain cases where base points are present. However, if the ideal defined by the parametrization is saturated, then this method rarely applies. Instead, we show that when the base points are a local complete intersection, the implicit equation can be computed as the resu

Steven Lillywhite

We define and discuss G-formality for certain spaces endowed with an action by a compact Lie group. This concept is essentially formality of the Borel construction of the space in a category of commutative differential graded algebras over R, where R is the cohomology of the classifying space BG. These results may be applied in computing the equivariant coho

James T. Liu, W. A. Sabra, W. Y. Wen

We construct consistent non-linear Kaluza Klein reduction ansatze for a subset of fields arising from the reduction of IIB* and M* theory on dS_5 x H^5 and dS_4 x AdS_7, respectively. These reductions yield four and five-dimensional de Sitter supergravities, albeit with wrong sign kinetic terms. We also demonstrate that the ansatze may be used to lift multi-

Martin Bojowald, Thomas Strobl

We determine the moduli space of classical solutions to the field equations of Poisson Sigma Models on arbitrary Riemann surfaces for Poisson structures with vanishing Poisson form class. This condition ensures the existence of a presymplectic form on the target Poisson manifold which agrees with the induced symplectic forms of the Poisson tensor upon pullba

D. Dudal, A. R. Fazio, V. E. R. Lemes, M. Picariello

Gluon and ghost condensates of dimension two and their relevance for Yang-Mills theories are briefly reviewed

Elcio Abdalla, Cecilia B. M. H. Chirenti

We consider a toy metric in four dimensional space-time defined in terms of a recursive hierarchical prescription. The matter distribution turns out to be extremely inhomogeneous. Surprisingly, for very large samples the average mass density tends (very slowly) to a constant. There is no trace of fractal dimension left.

Graeme Robertson

The theory of self-dual bosonic lumps immersed in the Cayley-calibrated space of octonions has a large class of exact finite quaternionic power series solutions.

Kang-Sin Choi, Kyuwan Hwang, Jihn E. Kim

A simple method for breaking gauge groups by orbifolding is presented. We extend the method of Kac and Peterson to include Wilson lines. The complete classification of the gauge group breaking, e.g. from heterotic string, is now possible. From this Dynkin diagram technique, one can easily visualize the origin and the symmetry pattern of the surviving gauge g

Eric Braaten, Masaoki Kusunoki, Yu Jia, Thomas Mehen

Asymmetries in the hadroproduction of charm particles directly probe power corrections to the QCD factorization theorems. In this paper, the heavy-quark recombination mechanism, a power correction that explains charm meson asymmetries, is extended to charm baryons. In this mechanism, a light quark participates in the hard scattering that creates a charm quar

Emil Mottola

The problem of maintaining gauge invariance in the 2PI formulation of QED is discussed. A modified form of the 2PI effective action is suggested in which Ward identities for external (background field) and internal (quantum field) gauge transformations are both satisfied, but in different manners. The residual gauge-fixing dependence in this modified 2PI for

David Grellscheid

We will present a method to decide a priori whether various supersymmetrical scenarios can be distinguished based on sparticle mass data alone. For each model, a scan over all free SUSY breaking parameters reveals the extent of that model's physically allowed region of sparticle-mass-space. Based on the geometrical configuration of these regions in mass-

Nicholas Petropoulos

A possible solution to the observed baryon asymmetry in the universe is described, based on the physics of the standard model of electroweak interactions. At temperatures high enough electroweak physics provides violation of baryon number, while C and CP symmetries are not exactly conserved, although in the context of the minimal electroweak model with one H

J. O. Eeg, K. Kumericki, I. Picek

In addressing the B --> eta' K puzzle, there has been a considerable hope in the literature to resolve it by the QCD anomaly contribution to the b --> s eta' amplitude. This contribution corresponds to the electroweak b --> s g* g* transition followed by the off-shell gluon fusion g* g* --> eta'. In the present paper we perform a critical reasses

A. Brandenburg, P. Nason, C. Oleari

Motivated by recent preliminary results from the SLD Collaboration on the measurement of angle-dependent B-Bbar energy correlations in Z^0 -> b bbar events, we propose a class of observables that can be computed as a power expansion in the strong coupling constant alpha_s, of order alpha_s at the Born level and that can be used for a precision measurement of

Michael Klasen

The production of J/Psi mesons in photon photon collisions allows for a test of factorization in color-octet processes as predicted by NRQCD and observed at the Tevatron. We calculate the cross sections for J/Psi production with direct and resolved photons, including also the feed-down from chi_{cJ} and Psi' decays. Our NRQCD predictions are nicely confi

B. Ziaja

In this thesis we consider the polarized deep inelastic scattering in the region of low values of Bjorken variable, $x$. We formulate the evolution equations for the unintegrated parton distributions which include a complete resummation of the double logarithmic contributions, $\ln^2(1/x)$. Afterwards, these equations are completed with the standard LO and N

B. Kampfer, J. Cleymans, P. Steinberg, S. Wheaton

The dependence of the strangeness saturation factor on the system size, centrality and energy is studied in relativistic heavy-ion collisions.

B. Ziaja

For an accurate description of the polarized deep inelastic scattering at low $x$ including the logarithmic corrections, $\ln^2(1/x)$, is required. These corrections resummed strongly influence the behaviour of the spin structure functions and their moments. Results of the work of J. Kwiecinski and myself on this problem are reviewed.}

Benjamin Grinstein, Michael Savrov

Duality is not violated at order Delta/M once j=3/2 and j=1/2+ states are properly accounted for.

Alessandro Strumia

Solar and atmospheric evidences have been established and can be explained by neutrino masses. Furthermore, other experiments claim a few unconfirmed neutrino anomalies. We critically reanalyze the 0nu2beta, LSND and NuTeV anomalies.

B. Aubert

We present a search for the rare flavour-changing neutral-current decay $B^{-}\to K^{-} ν\barν$ based on a sample of $(86.9 \pm 1.0) \times 10^{6}$ $Υ(4S) \to $B\bar{B}$ events collected by the BABAR experiment at the SLAC B-factory. Signal candidate events are selected by fully reconstructing a $B^+ \to \bar{D}^{0} X^+$ decay, where $X^+$ represents a combi

B. Aslan, G. Zech

We present a new class of multivariate binning-free and nonparametric goodness-of-fit tests. The test quantity \emph{energy} is a function of the distances of observed and simulated observations in the variate space. The simulation follows the probability distribution function $f_{0}$ of the null hypothesis. The distances are weighted with a weighting functi

Gabriela Gonzalez

It is expected that interferometric gravitational wave detectors such as LIGO \cite{Barish99} will be eventually limited by fundamental noise sources like shot noise and Brownian motion, as well as by seismic noise. In the commissioning process, other technical noise sources (electronics noise, alignment fluctuations) limit the sensitivity and are eliminated

Jérémie Vinet

We show that a recent letter claiming to present exact cosmological solutions in Brans-Dicke theory actually uses a flawed set of equations as the starting point for their analysis. The results presented in the letter are therefore not valid.

Clovis Jacinto de Matos, Martin Tajmar

The theory of General Relativity explaines the advance of Mercury perihelion using space curvature and the Schwartzschild metric. We demonstrate that this phenomena can also be interpreted due to the cogravitational field produced by the apparent motion of the Sun around Mercury giving exactly the same estimate as derived from the Schwartzschild metric in ge

V. B. Braginsky, A. A. Samoilenko

The results of measurement of optical mirror coating are presented. These results indicate that Standard Quantum Limit of sensitivity can be reached in the second stage of LIGO project if it is limited by thermoelastic noise in the coating only.

Stefan Weinzierl

This article documents the free computer algebra system "gTybalt". The program is build on top of other packages, among others GiNaC, TeXmacs and Root. It offers the possibility of interactive symbolic calculations within the C++ programming language. Mathematical formulae are visualized using TeX fonts.

K. D. Machado, P. Jóvári, J. C. de Lima, C. E. M. Campos

The local atomic order of an amorphous Ga$_{50}$Se$_{50}$ alloy produced by Mechanical Alloying (MA) was studied by the Extended X-ray Absorption Fine Structure (EXAFS) and X-ray Diffraction (XRD) techniques and by Reverse Monte Carlo (RMC) simulations of its total x-ray structure factor. The coordination numbers and interatomic distances for the first neigh

L. M. Abreu, A. P. C. Malbouisson, J. M. C. Malbouisson, A. E. Santana

We consider the $N$-component Ginzburg-Landau model in the large $N$ limit, the system being embedded in an external constant magnetic field and confined between two parallel planes a distance $L$ apart from one another. On physical grounds, this corresponds to a material in the form of a film in the presence of an external magnetic field. Using techniques f

A. M. Fogg, J. B. Claridge, G. R. Darling, M. J. Rosseinsky

The synthesis of LixBC (x > 0.5) by high temperature Li deintercalation from LiBC is demonstrated by refinement of X-ray and neutron powder diffraction data - contrary to theoretical expectation no superconductivity above 2K is observed in these materials

John A. Wilson

This paper seeks to synthesize much recent work on the HTSC materials around the latest STM results from Davis and coworkers. The conductance diffuse scattering results in particular are used as point of entry to discuss bosonic modes, both of condensed and uncondensed form. The bosonic mode picture is essential to understanding an ever growing range of obse

P. Pedri, L. Santos, P. Ohberg, S. Stringari

The expansion of a 1D Bose gas is investigated employing the Lieb-Liniger equation of state within the local density approximation. We show that during the expansion the density profile of the gas does not follow a self-similar solution, as one would expect from a simple scaling Ansatz. We carry out a variational calculation, which recovers the numerical res

S. M. Kazakov, J. Karpinski, J. Jun, P. Geiser

Single crystals of MgB2 and Mg(B1-xCx)2 have been grown using cubic anvil technique. Tc values vary in a wide range (39-9 K) with carbon content varying from 0 up to 16%. Using SiC as the precursor leads to C and not to Si substituted crystals. Micro-hardness measurements performed on MgB2 single crystals give average value of 1100 kg/mm2.

Alvaro Dominguez, Siegfried Dietrich

In thermal equilibrium, a colloidal particle between two parallel plates immersed in a fluid which partially wets both the particle and the plates, is attracted by the walls. However, if the particle moves parallel to the plates, a hydrodynamic lift force away from the plates arises in the limit of low Reynolds number. We study theoretically the competition

T. Aste, U. Valbusa

We study the morphological evolution of surfaces during ion sputtering and we compare their dynamical roughening with aeolian ripple formation in sandy deserts. We show that the two phenomena can be described within the same theoretical framework. This approach explains the different dynamical behaviors experimentally observed in metals or in semiconductors

M. H. Jung, A. Alsmadi, H. C. Kim, J. Kamarad

We report the normal-state transport and magnetic properties of a pressure-induced superconductor CeTe$_{1.82}$. We found that the applied pressure is required to increase the Kondo temperature scale ($T^*_{\rm K} \sim$ 170 K), associated with the two-dimensional motion of the carriers confined within the Te plane. Both the short-range ferromagnetic ordering

G. Maris, Y. Ren, V. Volotchaev, C. Zobel

We present powder and single crystal X-ray diffraction data as evidence for a monoclinic distortion in the low spin (S=0) and intermediate spin state (S=1) of LaCoO3. The alternation of short and long bonds in the ab plane indicates the presence of eg orbital ordering induced by a cooperative Jahn-Teller distortion. We observe an increase of the Jahn-Teller

Yves Colombe, Demascoth Kadio, Maxim Olshanii, Brigitte Mercier

We propose two loading mechanisms of a degenerate Bose gas into a surface trap. This trap relies on the dipole potential produced by two evanescent optical waves far detuned from the atomic resonance, yielding a strongly anisotropic trap with typical frequencies 40 Hz x 65 Hz x 30 kHz. We present numerical simulations based on the time-dependent Gross-Pitaev

Z. Z. Sun, H. T. He, J. N. Wang, Shi-dong Wang

The ac response of self-sustained current oscillations (SSCOs) in GaAs/AlAs superlattices (SLs) is derived based on the deformation of a limit cycle under an external ac driving force. Frequency locking into an integer fraction of the ac frequency is obtained in a periodic response in which a limit cycle deforms either with or without a topological change. T

Carina Kamaga, Denis Funfschilling, Michael Dennin

We report on the growth of domains of standing waves in electroconvection in a nematic liquid crystal. An ac voltage is applied to the system, forming an initial state that consists of travelling striped patterns with two different wavenumbers, zig and zag rolls. The standing waves are generated by suddenly applying a periodic modulation of the amplitude of

Anita Mehta, J. M. Luck

We present a stochastic model of dynamically interacting grains in one dimension, in the presence of a low vibrational intensity, to investigate the effect of shape on the statics and dynamics of the compaction process. Regularity and irregularity in grain shapes are shown to be centrally important in determining the statics of close-packing states, as well

Suzanne L. Hawley, Christopher M. Johns-Krull

We present results from our cycle 10 HST program to search for transition region emission in very low-mass, main-sequence stars in the spectral range M7-M9. Our program is aimed at 1) detecting emission; and 2) distinguishing between flaring and quiescent origin for the emission. We have obtained HST/STIS time series observations of three active, very low ma

E. A. Corbett, S. M. Croom, B. J. Boyle, H. Netzer

We have used composite spectra generated from more than 22000 QSOs observed in the course of the 2dF and 6dF QSO Redshift Surveys to investigate the relationship between the velocity width of emission lines and QSO luminosity. We find that the velocity width of the broad emission lines Hbeta, Hgamma, MgII, CIII] and CIV are correlated with the continuum lumi

S. Nazarenko, R. J. West, O. Zaboronski

The small-scale turbulent dynamo in the high Prandtl number regime is described in terms of the one-point Fourier space correlators. The second order correlator of this kind is the energy spectrum and it has been previously studied in detail. We examine the higher order k-space correlators which contain important information about the phases of the magnetic

M. -A. Miville-Deschenes, F. Levrier, E. Falgarone

Based on fractional Brownian motion (fBm) simulations of 3D gas density and velocity fields, we present a study of the statistical properties of spectro-imagery observations (channel maps, integrated emission, and line centroid velocity) in the case of an optically thin medium at various temperatures. The power spectral index gamma_W of the integrated emissi

Jeffrey E. McClintock, Ramesh Narayan, Michael R. Garcia, Jerome A. Orosz

We present an X-ray/UV/optical spectrum of the black hole primary in the X-ray nova XTE J1118+480 in quiescence at L_x = 4 x 10^{-9} of the Eddington luminosity. The Chandra, HST and MMT spectroscopic observations were performed simultaneously on 2002 January 12 UT. Because this 4.1-hr binary is located at b = 62 deg, the transmission of the ISM is very high

D. J. Saikia, Neeraj Gupta

The compact steep spectrum and gigahertz peaked spectrum sources are widely believed to be young radio sources, with ages <10^6 yr. If the activity in the nucleus is fuelled by the supply of gas, one might find evidence of this gas by studying the structural and polarization characteristics of CSS sources as these evolve through this gas. We present polariza

José Saucedo, Nuria Calvet, Lee Hartmann, John Raymond

New subarcsecond FUV observations of T Tau with HST/STIS show spatially resolved structures in the 2&#34;x2&#34; area around the star. The structures show in multiline emission of fluorescent H_2 pumped by Lyman alpha. One emission structure follows the cavity walls observed around T Tau N in scattered light in the optical. A temperature greater or equal to

S. Karaali, S. G. Ak, S. Bilir, Y. Karatas

We interpret published CCD UBVI data to deduce the stellar density distribution and metallicity distribution function in the region from 2-8 kpc from the Galactic Plane, and compare our results to several star count models. A feature of extant star count models is degeneracy between the adopted scale heights of the thin and thick disks, and their local norma

A. Franceschini, V. Braito, M. Persic, R. Della Ceca

XMM-Newton observations of 10 ULIRGs are reported. The aim is to investigate in hard X-rays a complete ULIRG sample selected from the bright IRAS 60$μ$m catalogue. All sources are detected in X-rays, 5 of which for the first time. These observations confirm that ULIRGs are intrinsically faint X-rays sources, their observed X-ray luminosities being typically

A. Barrau, G. Boudoul, L. Derome

Gamma-rays are, with antiprotons, a very efficient way to derive upper limits on the density of evaporating black holes. They have been successfully used in the last decades to severely constrain the amount of Primordial Black Holes (PBHs) in our Universe. This article suggests a little refinement, based on the expected background, to improve this limit by a

Roberto Trotta

We discuss the value of the cosmological constant as recovered from CMB and LSS data and the robustness of the results when general isocurvature initial conditions are allowed for, as opposed to purely adiabatic perturbations. The Bayesian and frequentist statistical approaches are compared. It is shown that pre-WMAP CMB and LSS data tend to be incompatible

L. Campanelli, P. Cea, G. L. Fogli, L. Tedesco

We investigate gravitational properties of thin planar wall solutions of the Einstein&#39;s equations in the weak field approximation. We find the general metric solutions and discuss the behavior of a particle placed initially at rest to one side of the plane. Moreover we study the case of non-reflection-symmetric solutions.

Richard D. Taylor, Philip Uttley, Ian M. McHardy

We use a model-independent technique to investigate the nature of the 2-15 keV X-ray spectral variability in four Seyfert galaxies and distinguish between spectral pivoting and the two-component model for spectral variability. Our analysis reveals conclusively that the softening of the X-ray continuum with increasing flux in MCG -6-30-15 and NGC 3516 is a re

Mark I. Wilkinson, Jarrod R. Hurley, A. Dougal Mackey, Gerard F. Gilmore

We use N-body simulations of star clusters to investigate the possible dynamical origins of the observed spread in core radius among intermediate-age and old star clusters in the Large Magellanic Cloud (LMC). Two effects are considered, a time-varying external tidal field and variations in primordial hard binary fraction. Simulations of clusters orbiting a p

E. Pian, P. Giommi, L. Amati, E. Costa

The error box of GRB980425 has been observed by XMM-Newton in March 2002, with the aim of measuring the late epoch X-ray emission of the supernova 1998bw and of clarifying its supposed association with the GRB itself. We present here the preliminary results obtained with the EPIC PN camera. Our observations confirm the association between SN 1998bw and GRB98

Eric Bois, Eric Trelut

We discuss the usual account of causal structure that relies on the temporal precedence constraint between cause-effect pairs. In particular, we consider the subtle interplay between local and global characters of time and causality encoded in General Relativity. We find that the temporal precedence constraint must be relaxed. We argue that these results cou

Elena Franciosini, Sofia Randich, Roberto Pallavicini

The Praesepe open cluster represents a puzzle since it has about the same age as the Hyades, and only slightly different metallicity, yet previous ROSAT observations resulted in a detection rate of cluster sources significantly lower than for the Hyades. We present a new 50 ksec observation of Praesepe performed with the EPIC instrument on board XMM-Newton,

Corinne Charbonnel, Ana Palacios

Low mass stars (< 2-2.5 M_sun) exhibit, at all the stages of their evolution, signatures of processes that require challenging modeling beyond the standard stellar theory. In this paper we focus on their peculiarities while they climb the red giant branch (RGB). We first compare the classical predictions for abundance variations due to the first dredge-up wi

J. Kube, B. T. Gaensicke, F. Euchner, B. Hoffmann

CVcat is a database that contains published data on cataclysmic variables and related objects. Unlike in the existing online sources, the users are allowed to add data to the catalogue. The concept of an ``open catalogue&#39;&#39; approach is reviewed together with the experience from one year of public usage of CVcat. New concepts to be included in the upco

N. L. Martin-Hernandez, A. Bik, L. Kaper, A. G. G. M. Tielens

A high quality, medium-resolution K-band spectrum has been obtained of the ultracompact HII region G29.96-0.02 with the Very Large Telescope (VLT). The slit was positioned along the symmetry axis of the cometary shaped nebula. Besides the spectrum of the embedded ionizing O star, the long-slit observation revealed the rich emission-line spectrum produced by

Elaine M. Sadler

Radio emission from early-type (E and S0) galaxies usually signals the presence of a central supermassive black hole. If radio luminosity and black-hole mass are correlated, then we can use the large sample of radio galaxies observed in the 2dF Galaxy Redshift Survey (2dFGRS) to estimate the local (z<0.1) black-hole mass function for early-type galaxies. Int

Ue-Li Pen

We present a new algorithm to rapidly and optimally compute power spectra. This new algorithm is based on a generalization of iterative multigrid, and has computational cost O(N log N), compared to the standard brute force approach which costs O(N^3). The procedure retains this speed on the full sky and for ill-conditioned matrices. It is applicable to galax

PHENIX Collaboration, S. S. Adler

The invariant differential cross section for inclusive neutral pion production in p+p collisions at sqrt(s_NN) = 200 GeV has been measured at mid-rapidity |eta| < 0.35 over the range 1 < p_T <~ 14 GeV/c by the PHENIX experiment at RHIC. Predictions of next-to-leading order perturbative QCD calculations are consistent with these measurements. The precision of

B. C. Sanctuary

Long-range quantum correlations between particles are usually formulated by assuming the persistence of an entangled state after the particles have spearated. Here this approach is re-examined based upon studying the correlations present in a pair of EPR spins. Two types of correltions are identified. The first, due to the quantum interference terms is parit

B. C. Sanctuary, Mangala Sunder Krishnan, S. Presse, Wei Chen

The phenomenon called quantum &#34;teleportation&#34; has been formulated assuming the presence of entangled states and is interpreted as a realization of quantum non-locality. In contrast, correlations from both entanglement and disentanglement upon particle spearation exists and both of these are built into the EPR pair as they move apart. Here it is shown

Alex G. Kim, Eric V. Linder, Ramon Miquel, Nick Mostek

Mapping the recent expansion history of the universe offers the best hope for uncovering the characteristics of the dark energy believed to be responsible for the acceleration of the expansion. In determining cosmological and dark-energy parameters to the percent level, systematic uncertainties impose a floor on the accuracy more severe than the statistical

S. J. Lindenbaum, R. S. Longacre, M. Kramer

Since the early eighties, we have shared with Leon Van Hove the following view. That if a QGP were produced in high energy heavy ion colliders, that its hadronization products would likely come from small localized in phase space bubbles of plasma. We develop a model based on HIJING, to which we added a ring of adjoining multiple bubbles in the central rapid

Michael Gutperle, Renata Kallosh, Andrei Linde

Recently it was observed that the hyperbolic compactification of M/string theory related to S-branes may lead to a transient period of acceleration of the universe. We study time evolution of the corresponding effective 4d cosmological model supplemented by cold dark matter and show that it is marginally possible to describe observational data for the late-t

John McGreevy, Herman Verlinde

We propose a new interpretation of the c=1 matrix model as the world-line theory of N unstable D-particles, in which the hermitian matrix is provided by the non- abelian open string tachyon. For D-particles in 1+1-d string theory, we find a direct quantitative match between the closed string emission due to a rolling tachyon and that due to a rolling eigenva

Efrat Shimshoni, Natan Andrei, Achim Rosch

We study the low-temperature transport properties of clean one-dimensional spin-1/2 chains coupled to phonons. Due to the presence of approximate conservation laws, the heat current decays very slowly giving rise to an exponentially large heat conductivity, $κ~ e^{T^*/T}$. As a result of an interplay of Umklapp scattering and spinon-phonon coupling, the char

Jianqiang Zhao

We shall define the q-analogs of multiple zeta functions and multiple polylogarithms in this paper and study their properties, based on the work of Kaneko et al. and Schlesinger, respectively.

Philippe Raynal, Norbert Lütkenhaus, Steven J. van Enk

We present reduction theorems for the problem of optimal unambiguous state discrimination (USD) of two general density matrices. We show that this problem can be reduced to that of two density matrices that have the same rank $n$ and are described in a Hilbert space of dimensions $2n$. We also show how to use the reduction theorems to discriminate unambiguou

Laurence J. November

We show that the atmospheric and magnetic height variations are coupled in general MHS equilibria with gravity when isolated thin non-force-free flux tubes are present. In gas-dominated environments, as in stellar photospheres, flux tubes must expand rapidly with height to maintain pressure balance with the cool surroundings. But in magnetically dominated en

Francesco Baldassarri, Andrea D&#39;Agnolo

After works by Katz, Monsky, and Adolphson-Sperber, a comparison theorem between relative de Rham cohomology and Dwork cohomology is established in a paper by Dimca-Maaref-Sabbah-Saito in the framework of algebraic D-modules. We propose here an alternative proof of this result. The use of Fourier transform techniques makes our approach more functorial.

S. Miller, S. Luding

Dissipation in granular media leads to interesting phenomena as there are cluster formation and crystallization in non-equilibrium dynamical states. The freely cooling system is examined concerning the energy decay and the cluster evolution in time, both in two and three dimensions. Interesting parallels to percolation theory are obtained in three dimensions

Somnath Bharadwaj, Sayan Kar

We investigate whether a dark matter with substantial amounts of pressure, comparable in magnitude to the energy density, could be a viable candidate for the constituent of dark matter halos. We find that galaxy halos models, consistent with observations of flat rotation curves, are possible for a variety of equations of state with anisotropic pressures. It

Rahul Biswas, Esko Keski-Vakkuri, Robert G. Leigh, Sean Nowling

We consider a $R^{1,d}/Z_2$ orbifold, where $Z_2$ acts by time and space reversal, also known as the embedding space of the elliptic de Sitter space. The background has two potentially dangerous problems: time-nonorientability and the existence of closed time-like curves. We first show that closed causal curves disappear after a proper definition of the time

F. A. Smirnov, A. M. Tsvelik

For the model of frustrated spin-1/2 Heisenberg magnet described in A. A. Nersesyan and A. M. Tsvelik, (Phys. Rev. B{\bf 67}, 024422 (2003)) we calculate correlation functions of staggered magnetization and dimerization. The model is formulated as a collection of antiferromagnetic chains weakly coupled by a frustrated exchange interaction. The calculation do

Stefan Forste, Daniel Roggenkamp

Moduli spaces of conformal field theories corresponding to current-current deformations are discussed. For WZW models, CFT and sigma model considerations are compared. It is shown that current-current deformed WZW models have WZW-like sigma model descriptions with non-bi-invariant metrics, additional B-fields and a non-trivial dilaton.

Joachim Kock, Bertrand Toën

We show that if $(M,\tensor,I)$ is a monoidal model category then $\REnd_M(I)$ is a (weak) 2-monoid in $\sSet$. This applies in particular when $M$ is the category of $A$-bimodules over a simplicial monoid $A$: the derived endomorphisms of $A$ then form its Hochschild cohomology, which therefore becomes a simplicial 2-monoid.