January 2006 arXiv papers — page 30

Miguel Couceiro, Maurice Pouzet

It was proved few years ago that classes of Boolean functions definable by means of functional equations \cite{EFHH}, or equivalently, by means of relational constraints \cite{Pi2}, coincide with initial segments of the quasi-ordered set $(Ω, \leq)$ made of the set $Ω$ of Boolean functions, suitably quasi-ordered. The resulting ordered set $(Ω/\equiv, \sqsub

Luc Molinet, Francis Ribaud

We prove the local well posedness of the Benjamin-Ono equation and the generalized Benjamin-Ono equation in $ H^1(\T) $. This leads to a global well-posedness result in $ H^1(\T)$ for the Benjamin-Ono equation.

I. Kopshaev, A. Sultanbekova

In this paper we consider the families of morphisms of vector fibre bundles (\cite{Mill1}) defined by the linear systems of differential equations. We proving that the specified families of morphisms is not saturated (\cite{Mill2}).

Ben Green

The Hardy-Littlewood method is a well-known technique in analytic number theory. Among its spectacular applications are Vinogradov's 1937 result that every sufficiently large odd number is a sum of three primes, and a related result of Chowla and Van der Corput giving an asymptotic for the number of 3-term progressions of primes, all less than N. This ar

D. Barlet

We show in this note that for a germ $g$ of holomorphic function with an isolated singularity at the origin of $\mathbb{C}^n$ there is a pole for the meromorphic extension of the distribution \begin{equation*} \frac{1}{Γ(λ)} \int_X | g |^{2λ}\bar{g}^{-n} \square \tag{*} \end{equation*} at $- n - α$ when $ α$ is the smallest root in its class modulo $\mathbb{

Bruce W. Westbury

We construct a pivotal category by a finite presentation and show that it is an integral form of the category of invariant tensors of the spin representation of the quantum group U_q(B_3) over the field of rational functions in q.

A. Brudnyi, Yu. Brudnyi

A metric space has the universal Lipschitz extension property if for each subspace S embedded quasi-isometrically into an arbitrary metric space M there exists a continuous linear extension of Banach-valued Lipschitz functions on S to those on all of M. We show that the finite direct sum of Gromov hyperbolic spaces of bounded geometry is universal in the sen

Roland K. W. Roeder

Errors are found in example problems from Henri Poincaré's paper ``Mémoire sur les courbes définies par une équation différentielle.'' Examples four and five from chapter seven and examples one, two, and three from chapter nine do not have the limit cycles at infinity predicted by Poincaré. Instead they have fixed points at every point at infinit

Kai Behrend, Jim Bryan

We solve the part of the Donaldson-Thomas theory of Calabi-Yau threefolds which comes from super-rigid rational curves. As an application, we prove a version of the conjectural Gromov-Witten/Donaldson-Thomas correspondence for contributions from super-rigid rational curves. In particular, we prove the full GW/DT correspondence for the quintic threefold in de

Christopher Lin, Zhiqin Lu

In this paper, we study the spectrum of quantum tubes. Under certain intrinsic assumptions of the asymptotically flat submanifold of the Euclidean space, we prove the existence of the ground state of the quantum tube. The work is a generalization of Duclos, Exner and Krejcirik (CMP, 223(1), 13-28, 2001) and ourselves(math.DG/0402252).

Eduardo Pina

The altenating knots, links and twists projected on the S_2 sphere are identified with the phase Space of a Hamiltonian dynamic system of one degree of freedom. The saddles of the system correspond to the crossing points, the edges, to the stable and unstable manifolds, connecting the saddles. Each facxe is then oriented in one of two different senses determ

Wolfgang P. Angerer

For a finite mean supercriticial Bellman-Harris process, there exist numbers $χ_t$ (the Seneta constants) such that $χ_t$ times the size of the population at time $t$ converges almost surely to a non-degenerate limit. We obtain a characterisation of the slowly varying part of the Seneta constants under the assumption that the life-time distribution of partic

Landon Rabern

A \emph{$k$--decomposition} of the complete graph $K_n$ is a decomposition of $K_n$ into $k$ spanning subgraphs $G_1,...,G_k$. For a graph parameter $p$, let $p(k;K_n)$ denote the maximum of $\displaystyle \sum_{j=1}^{k} p(G_j)$ over all $k$--decompositions of $K_n$. It is known that $χ(k;K_n) = omega(k;K_n)$ for $k \leq 3$ and conjectured that this equality

Isabel Fernandez, Pablo Mira

It has been recently shown by Abresch and Rosenberg that a certain Hopf differential is holomorphic on every constant mean curvature surface in a Riemannian homogeneous 3-manifold with isometry group of dimension 4. In this paper we describe all the surfaces with holomorphic Hopf differential in the homogeneous 3-manifolds isometric to H^2xR or having isomet

J. J. Duistermaat, A. Pelayo

In this paper we completely classify symplectic actions of a torus $T$ on a compact connected symplectic manifold $(M, σ)$ when some, hence every, principal orbit is a coisotropic submanifold of $(M, σ)$. That is, we construct an explicit model, defined in terms of certain invariants, of the manifold, the torus action and the symplectic form. The invariants

Nicolas Roy

We study several aspects of the regular deformations of completely integrable systems. Namely, we prove the existence of a Hamiltonian normal form for these deformations and we show the necessary and sufficient conditions a perturbation has to satisfy in order for the perturbed Hamiltonian to be a first order deformation.

Alberto Della Vedova, Roberto Paoletti

Suppose given a linearized action on a polarized complex projective manifold (M,L), and assume that the stable locus is non-empty. We study the leading asymptotics of the dimension of the equivariant summands appearing in the space of global sections of high powers of L. We use Kirwan resolutions and an elementary algebro-geometric argument to reduce the pro

Bernhard Kroetz, Robert J. Stanton

Let G be a connected, real, semisimple Lie group contained in its complexification G_C, and let K be a maximal compact subgroup of G. We construct a K_C-G double coset domain in G_C, and we show that the action of G on the K-finite vectors of any irreducible unitary representation of G has a holomorphic extension to this domain. For the resultant holomorphic

Gor Sarkissian

We study the modifications of the generalized permutation branes defined in hep-th/0509153, which are required to give rise to the non-factorizable branes on a product of cosets $G_{k_1}/H\times G_{k_2}/H$. We find that for $k_1\neq k_2$ there exists big variety of branes, which reduce to the usual permutation branes, when $k_1=k_2$ and the permutation symme

Marek Rogatko

We derive the first law of black rings thermodynamics in n-dimensional Einstein dilaton gravity with additional (p+1)-form field strength being the simplest generalization of five-dimensional theory containing a stationary black ring solution with dipole charge. It was done by means of choosing any cross section of the event horizon to the future of the bifu

T. Heinzl, B. Liesfeld, K. -U. Amthor, H. Schwoerer

We suggest an experiment to observe vacuum birefringence induced by intense laser fields. A high-intensity laser pulse is focused to ultra-relativistic intensity and polarizes the vacuum which then acts like a birefringent medium. The latter is probed by a linearly polarized x-ray pulse. We calculate the resulting ellipticity signal within strong-field QED a

Francois Arleo

Single pion and prompt photon large transverse momentum spectra in p-p and Au-Au collisions are computed in perturbative QCD at RHIC energy, s^1/2 = 200 GeV. Next-to-leading order calculations are discussed and compared with p-p scattering data. Subsequently, quenching factors are computed to leading order for both pions and photons within the same energy lo

Alexander A. Osipov, Brigitte Hiller, Joao Moreira, Alex H. Blin

The functional integration over the auxiliary bosonic variables of cubic order related with the effective action of the Nambu -- Jona-Lasinio model with 't Hooft term has recently been obtained in the form of a loop expansion. Even numbers of loops contribute to the action, while odd numbers of loops are assigned to the measure. We consider the two-loop

A. Gehrmann-De Ridder, T. Gehrmann, E. Poulsen

Photon radiation at large transverse momenta at colliders is a detailed probe of hard interaction dynamics. The isolated photon production cross section in deep inelastic scattering was measured recently by the ZEUS experiment, and found to be considerably larger than theoretical predictions obtained with widely used event generators. To investigate this dis

A. E. Kaloshin, V. P. Lomov

We obtain in analytical form the dressed propagator of the massive Rarita-Schwinger field and discuss its properties. The calculation of the self-energy contributions demonstrates that besides $s=3/2$ component the Rarita-Schwinger field contains also two $s=1/2$ components of opposite parity.

M. Hirai, S. Kumano, T. -H. Nagai

We investigate a possible explanation for the NuTeV anomaly in terms of a nuclear correction difference between u_v and d_v distributions. Analyzing deep elastic scattering and Drell-Yan data for nuclear targets, we try to determine the correction difference and its effect on the anomaly. We find that the difference cannot be precisely determined at this sta

Wu Peng, Ma Wen-Gan, Zhang Ren-You, Jiang Yi

We present the next-to-leading order QCD corrected total cross sections and the distributions of the transverse momenta of the final anti-bottom-quark, top-quark and charged Higgs-boson for the processes of $p\bar p/pp \to t\bar b H^-+X$ in the minimal supersymmetric standard model(MSSM) at the Tevatron and the LHC. We find that the NLO QCD corrections signi

Giuseppe Marchesini

I review recent results on soft gluon radiation at large angles

Stephan Narison

We review the determinations of the pseudoscalar glueball and eventual radial excitation of the η' masses and decay constants from QCD spectral sum rules (QSSR). The glueball mass is (2.05+-0.19) which one can compare with the eventual experimental candidate X(1835), while the η(1400) is likely a radial excitation of the η'-meson. Their effects on th

Toshitaka Tatsumi

A magnetic aspect of quark matter is studied by the Fermi liquid theory. The magnetic susceptibility is derived with the one-gluon-exchange interaction, and the critical Fermi momentum for spontaneous spin polarization is found to be 1.4fm^{-1}. A scenario about the origin of the magnetic field in compact stars is presented by using this result.

Chris T Sachrajda

I present a selection of recent lattice results in flavourdynamics, including the status of the calculation of quark masses and a variety of weak matrix elements relevant for the determination of CKM matrix elements. Recent improvements in the momentum resolution of lattice computations and progress towards precise computations of $K\toππ$ decay amplitudes a

C. Voena

The time-dependent CP asymmetries in fully reconstructed B0 --> D(*)pi/rho decays (new preliminary result), and in partially reconstructed B0 --> D(*)pi decays, are measured with the BaBar detector at the PEP-II asymmetric B factory at SLAC, using 232 million Y(4S) -> BB decays. We combine the above results and, using other measurements and theoretical assum

S. Carlip

Black hole entropy appears to be ``universal''--many independent calculations, involving models with very different microscopic degrees of freedom, all yield the same density of states. I discuss the proposal that this universality comes from the behavior of the underlying symmetries of the classical theory. To impose the condition that a black hole

German Izquierdo

The possibility of reconstructing the whole history of the scale factor of the Universe from the power spectrum of relic gravitational waves (RGWs) makes the study of these waves quite interesting. First, we explore the impact of a hypothetical era -right after reheating- dominated by mini black holes and radiation that may lower the spectrum several orders

Christoph Benzmueller, John Harrison, Carsten Schuermann

This workshop brings together practioners and researchers who are involved in the everyday aspects of logical systems based on higher-order logic. We hope to create a friendly and highly interactive setting for discussions around the following four topics. Implementation and development of proof assistants based on any notion of impredicativity, automated th

Michael Langberg

Let C = {x_1,...,x_N} \subset {0,1}^n be an [n,N] binary error correcting code (not necessarily linear). Let e \in {0,1}^n be an error vector. A codeword x in C is said to be "disturbed" by the error e if the closest codeword to x + e is no longer x. Let A_e be the subset of codewords in C that are disturbed by e. In this work we study the size of A_

Michel Parent

In the past few years, the European Commission has financed several projects to examine how new technologies could improve the sustainability of European cities. These technologies concern new public transportation modes such as guided buses to form high capacity networks similar to light rail but at a lower cost and better flexibility, PRT (Personal Rapid T

Maria Alpuente, Santiago Escobar, Salvador Lucas

The application of automatic transformation processes during the formal development and optimization of programs can introduce encumbrances in the generated code that programmers usually (or presumably) do not write. An example is the introduction of redundant arguments in the functions defined in the program. Redundancy of a parameter means that replacing i

Giorgio Delzanno

We present a technique for the automated verification of abstract models of multithreaded programs providing fresh name generation, name mobility, and unbounded control. As high level specification language we adopt here an extension of communication finite-state machines with local variables ranging over an infinite name domain, called TDL programs. Communi

Giorgio Delzanno

We present a technique for the automated verification of abstract models of multithreaded programs providing fresh name generation, name mobility, and unbounded control. As high level specification language we adopt here an extension of communication finite-state machines with local variables ranging over an infinite name domain, called TDL programs. Communi

Vincent D. Blondel, Raphael Jungers, Vladimir Protasov

We consider questions related to the computation of the capacity of codes that avoid forbidden difference patterns. The maximal number of $n$-bit sequences whose pairwise differences do not contain some given forbidden difference patterns increases exponentially with $n$. The exponent is the capacity of the forbidden patterns, which is given by the logarithm

Francois Colonna

We propose some slight additions to O-O languages to implement the necessary features for using Deductive Object Programming (DOP). This way of programming based upon the manipulation of the Production Tree of the Objects of Interest, result in making Persistent these Objects and in sensibly lowering the code complexity.

Rolf Klein, Martin Kutz

Consider a plane graph G, drawn with straight lines. For every pair a,b of vertices of G, we compare the shortest-path distance between a and b in G (with Euclidean edge lengths) to their actual distance in the plane. The worst-case ratio of these two values, for all pairs of points, is called the dilation of G. All finite plane graphs of dilation 1 have bee

J. J. Hamlin, V. G. Tissen, J. S. Schilling

In an experiment in a diamond anvil cell utilizing helium pressure medium, yttrium metal displays a superconducting transition temperature which increases monotonically from Tc ? 3.5 K at 30 GPa to 17 K at 89.3 GPa, one of the highest transition temperatures for any elemental superconductor. The pressure dependence of Tc differs substantially from that obser

N. Garcia, L. R. Tagirov

Transparency of the metal/superconductor interface is discussed in a frame of the Kupryanov-Lukichev (K-L) quasiclassical boundary conditions. It is shown that the original K-L boundary transparency is expressed via the single-channel Landauer conductance. It is a source of dramatic discrepancy between the theory and experiments on the superconducting proxim

H. A. Fernandes, J. R. Drugowich de Felicio, A. A. Caparica

We investigate the critical dynamics of a classical ferromagnet on the simple cubic lattice with double-exchange interaction. Estimates for the dynamic critical exponents $z$ and $θ$ are obtained using short-time Monte Carlo simulations. We also estimate the static critical exponents $ν$ and $β$ studying the behavior of the samples at an early time. Our resu

J. Javier Brey, M. J. Ruiz-Montero, F. Moreno

The hydrodynamic state of an impurity immersed in a low density granular gas is analyzed. Explicit expressions for the temperature and density fields of the impurity in terms of the hydrodynamic fields of the gas are derived. It is shown that the ratio between the temperatures of the two components, measuring the departure from energy equipartition, only dep

Ronald Blaak, Jean-Pierre Hansen

We present extensive Molecular Dynamics simulation results for the structure, static and dynamical response of a droplet of 1000 soft spheres carrying extended dipoles and confined to spherical cavities of radii $R=2.5$, 3, and 4 nm embedded in a dielectric continuum of permittivity $ε' \geq 1$. The polarisation of the external medium by the charge distr

Pui-Man Lam, J. C. Levy

We study theoretically the unzipping of a double stranded DNA from a condensed globule state by an external force. At constant force, we find that the double stranded DNA unzips an at critical force Fc and the number of unzipped monomers M goes as M~(Fc-F)^{-3}, for both the homogeneous and heterogeneous double stranded DNA sequence. This is different from t

A. V. Koudinov, N. S. Averkiev, Yu. G. Kusrayev, B. R. Namozov

The degree and orientation of the magnetic-field induced linear polarization of the photoluminescence from a wide range of heterostructures containing (Cd,Mn)Te quantum wells between (Cd,Mn,Mg)Te barriers has been studied as a function of detection photon energy, applied magnetic field strength and orientation in the quantum well plane. A theoretical descrip

K. -Y. Choi, M. Grove, P. Lemmens, M. Fischer

We report inelastic light scattering experiments in the spin-chain and ladder system Sr_14-xCa_xCu_24O_41. A depletion of an electronic background is observed for 0 < x < 5 at low temperatures and with light polarization both parallel to the leg and rung directions. This points to the formation of 2D charge density wave in the ladders. Furthermore, the Ca-su

Maria Stamenova, Sudhakar Sahoo, Cristian G. Sanchez, Tchavdar N. Todorov

We investigate the interplay between magnetic and structural dynamics in ferromagnetic atomic point contacts. In particular, we look at the effect of the atomic relaxation on the energy barrier for magnetic domain wall migration and, reversely, at the effect of the magnetic state on the mechanical forces and structural relaxation. We observe changes of the b

Vikram Gadagkar, Prabal K. Maiti, Yves Lansac, A. Jagota

We use classical molecular dynamics simulations to study the collapse of single (SWNT) and double-walled (DWNT) carbon nanotube bundles under hydrostatic pressure. The collapse pressure (pc) varies as 1/R^3, where R is the SWNT radius or the DWNT effective radius. The bundles show ~ 30% hysteresis and the hexagonally close packed lattice is completely restor

Bernard Zappoli, Raphaël Cherrier, Didier Lasseux, Jalil Ouazzani

We investigate the critical speeding up of heat equilibration by the piston effect (PE) in a nearly supercritical van der Waals (vdW) fluid confined in a homogeneous porous medium. We perform an asymptotic analysis of the averaged linearized mass, momentum and energy equations to describe the response of the medium to a boundary heat flux. While nearing the

K. Ch. Chatzisavvas, S. E. Massen, Ch. C. Moustakidis, C. P. Panos

An overview of the Bose-Einstein condensation of correlated atoms in a trap is presented by examining the effect of interparticle correlations to one- and two-body properties of the above systems at zero temperature in the framework of the lowest order cluster expansion. Analytical expressions for the one- and two-body properties of the Bose gas are derived

M. K. Kneip, D. R. Yakovlev, M. Bayer, G. Karczewski

The technological concept of &#34;digital alloying&#34; offered by molecular-beam epitaxy is demonstrated to be a very effective tool for tailoring static and dynamic magnetic properties of diluted magnetic semiconductors. Compared to common &#34;disordered alloys&#34; with the same Mn concentration, the spin-lattice relaxation dynamics of magnetic Mn ions h

J. M. Aguiar Hualde, G. Chiappe, E. V. Anda

The Zeeman splitting of localized electrons in a quantum dot in the Kondo regime is studied using a new slave-boson formulation. Our results show that the Kondo peak splitting depends on the gate potential applied to the quantum dot and on the topology of the system. A common fact of any geometry is that the differential susceptibility shows a strong non lin

S. X. Dou, W. K. Yeoh, O. Shcherbakova, J. Horvat

Magnetic field of up to 12 T was applied during the sintering process of pure MgB2 and carbon nanotube (CNT) doped MgB2 wires. We have demonstrated that magnetic field processing results in grain refinement, homogeneity and significant enhancement in Jc(H) and Hirr. The Jc of pure MgB2 wire increased by up to a factor of 3 to 4 and CNT doped MgB2 by up to an

Eran Segev, Baleegh Abdo, Oleg Shtempluck, Eyal Buks

Fast resonance frequency modulation of a superconducting stripline resonator is investigated. The experiments are performed using a novel device which integrates a hot electron detector (HED) into a superconducting stripline ring resonator. Frequency modulation is demonstrated by both applying dc current or voltage to the HED, and by applying optical illumin

Hua-Jun Huang, Guang-Ming Zhang

Motivated by the recent experimental work (A. Widera, \textit{et al}, Phys. Rev. Lett. 95, 19045), we study the collisional spin dynamics of two spin-2 $% ^{87}$Rb atoms confined in a deep optical lattice. When the system is initialized as $|0,0>$, three different two-particle Zeeman states are involved in the time evolution due to the conservation of magnet

Yuanzhi Shao, Weirong Zhong, Zhenhui He

We report the nonequilibrium dynamical phase transition (NDPT) appearing in a kinetic Ising spin system (ISS) subject to the joint application of a deterministic external field and the stochastic mutually correlated noises simultaneously. A time-dependent Ginzburg-Landau stochastic differential equation, including an oscillating modulation and the correlated

Andrew N. Norris

The dynamic impedance of a sphere oscillating in an elastic medium is considered. Oestreicher&#39;s formula for the impedance of a sphere bonded to the surrounding medium can be expressed simply in terms of three lumped impedances associated with the displaced mass and the longitudinal and transverse waves. If the surface of the sphere slips while the normal

Hosho Katsura, Alexander V. Balatsky, Zohar Nussinov, Naoto Nagaosa

We present a theory of Landau-Lifshitz-Gilbert damping $α$ for a localized spin ${\vec S}$ in the junction coupled to the conduction electrons in both leads under an applied volatege $V$. We find the voltage dependence of the damping term reflecting the energy dependence of the density of states. We find the effect is linear in the voltage and cotrolled by p

Peter Hitchcock, Erik S. Sorensen

We present a Monte Carlo study of the Bose-glass to superfluid transition in the three-dimensional Bose-Hubbard model. Simulations are performed on the classical (3 + 1) dimensional link-current representation using the geometrical worm algorithm. Finite-size scaling analysis (on lattices as large as 16x16x16x512 sites) of the superfluid stiffness and the co

J. Dzubiella, J. M. J. Swanson, J. A. McCammon

Recent studies on the solvation of atomistic and nanoscale solutes indicate that a strong coupling exists between the hydrophobic, dispersion, and electrostatic contributions to the solvation free energy, a facet not considered in current implicit solvent models. We suggest a theoretical formalism which accounts for coupling by minimizing the Gibbs free ener

Peter Hitchcock, Erik S. Sorensen

We address computational issues relevant to the study of disordered quantum mechanical systems at very low temperatures. As an example we consider the disordered Bose- Hubbard model in three dimensions directly at the Bose-glass to superfluid phase transition. The universal aspects of the critical behaviour are captured by a (3 + 1) dimensional link-current

M. H. Ernst, R. Brito

We present a generalization of the Green-Kubo expressions for thermal transport coefficients $μ$ in complex fluids of the generic form, $μ= μ_\infty +\int^\infty_0 dt V^{-1} < J_ε\exp(t {\cal L}) J >_0$, i.e. a sum of an instantaneous transport coefficient $μ_\infty$, and a time integral over a time correlation function in a state of thermal equilibrium betw

M. H. Ernst, R. Brito

We present generalized Green-Kubo expressions for thermal transport coefficients $μ$ in non-conservative fluid-type systems, of the generic form, $μ$ $= μ_\infty$ $+\int^\infty_0 dt V^{-1} \av{I_ε\exp(t {\cal L}) I}_0$ where $\exp(t{\cal L})$ is a pseudo-streaming operator. It consists of a sum of an instantaneous transport coefficient $μ_\infty$, and a time

J. W. Quilty, A. Shibata, J. -Y. Son, K. Takubo

X-ray photoemission spectroscopy measurements were performed on thin-film samples of rutile Ti_{1-x}Co_{x}O_{2-delta} to reveal the electronic structure. The Co 2p core level spectra indicate that the Co ions take the high-spin Co 2+ configuration, consistent with substitution on the Ti site. The high spin state and the shift due to the exchange splitting of

B. Michaelis, C. Emary, C. W. J. Beenakker

We present a fully electronic analogue of coherent population trapping in quantum optics, based on destructive interference of single-electron tunneling between three quantum dots. A large bias voltage plays the role of the laser illumination. The trapped state is a coherent superposition of the electronic charge in two of these quantum dots, so it is destab

D. K. Sunko

The cluster cumulant formula of Kubo is derived by appealing only to elementary properties of subsets and binomial coefficients. It is shown to be a binomial transform of the grand potential. Extensivity is proven without introducing cumulants. A combinatorial inversion is used to reformulate the expansion in the activity to one in occupation probabilities,

S. C. Keller, P. R. Wood

We utilize nonlinear pulsation models to reproduce the observed light and color curves for two samples of bump Cepheid variables, 19 from the Large Magellanic Cloud and 9 from the Small Magellanic Cloud. This analysis determines the fundamental parameters mass, luminosity, effective temperature, metallicity, distance and reddening for the sample of stars. Th

F. Masset, A. Morbidelli, A. Crida, J. Ferreira

[Abridged] The tidal torque exerted by a protoplanetary disk with power law surface density and temperature profiles onto an embedded protoplanetary embryo is generally a negative quantity that leads to the embryo inwards migration. Here we investigate how the tidal torque balance is affected at a disk surface density radial jump. The jump has two consequenc

Mark A. Norris, Ray M. Sharples, Harald Kuntschner

We present Gemini GMOS longslit spectroscopy of the isolated S0 galaxy NGC 3115. We have determined kinematical data and Lick/IDS absorption line-strength indices for the major axis out to around 9 kpc and for the minor axis out to around 5 kpc (around 2Re). Using stellar population models which include the effects of variable [alpha/Fe] ratios we derive met

Kazuya Koyama

We study structure formation in phenomenological models in which the Friedmann equation receives a correction of the form $H^α/r_c^{2-α}$, which realize an accelerated expansion without dark energy. In order to address structure formation in these model, we construct simple covariant gravitational equations which give the modified Friedmann equation with $α=

Francesco R. Ferraro

Recent high-resolution observations of the central region of Galactic globular clusters have shown the presence of a large variety of exotic stellar objects whose formation and evolution may be strongly affected by dynamical interactions. In this paper I review the main properties of two classes of exotic objects: the so-called Blue Stragglers stars and the

Volker Bromm, Abraham Loeb

Gamma-Ray Bursts (GRBs) are unique probes of the cosmic star formation history and the state of the intergalactic medium up to the redshifts of the first stars. In particular, the ongoing {\it Swift} mission might be the first observatory to detect individual Population~III stars, provided that the massive, metal-free stars were able to trigger GRBs. {\it Sw

A. Bartkevicius, J. Sperauskas

The spectroscopic orbit of a circumpolar high-proper-motion visual binary BD +82 565 A component is determined from 57 CORAVEL radial velocity measurements. A short period P = 12.69 d and a moderate eccentricity e = 0.30 are obtained. The visual system AB has a projected spatial separation ~830 AU. The system&#39;s barycenter velocity V_0 = -86.7 km/s, the t

Mario H. Pedreros, Edgardo Costa, Rene A. Mendez

We have determined the proper motion (PM) of the Large Magellanic Cloud (LMC) relative to four background quasi-stellar objects, combining data from two previous studies made by our group, and new observations carried out in four epochs not included the original investigations. The new observations provided a significant increase in the time base and in the

M. Jardine, A. Collier Cameron, J. -F. Donati, S. G. Gregory

We have modelled the X-ray emission of T Tauri stars assuming that they have isothermal, magnetically-confined coronae. These coronae extend outwards until either the pressure of the hot coronal gas overcomes the magnetic field, or, if the corona interacts with a disk before this happens, by the action of the disk itself. This work is motivated by the result

A. Bartkevicius, J. Sperauskas

Here we publish the second list of radial velocities for 91 Hipparcos stars, mostly high transverse velocity binaries without previous radial velocity measurements. The measurements of radial velocities are done with a CORAVEL-type radial velocity spectrometer with an accuracy better than 1 km/s. We also present the information on eight new radial velocity v

Hai-Lang Dai, Xiang-Dong Li

The conventional picture of disk accretion onto magnetized neutron stars has been challenged by the spin changes observed in a few X-ray pulsars, and by theoretical results from numerical simulations of disk-magnetized star interactions. These indicate possible accretion during the propeller regime and the spin-down torque increasing with the accretion rate.

C. I. Short, P. H. Hauschildt

We present atmospheric models of red giant stars of various metallicities, including extremely metal poor (XMP, [Fe/H]<-3.5) models, with many chemical species, including, significantly, the first two ionization stages of Strontium (Sr) and Barium (Ba), treated in Non-Local Thermodynamic Equilibrium (NLTE) with various degrees of realism. We conclude that 1)

A Georgakakis, V. Chavushyan, M. Plionis, I. Georgantopoulos

This paper uses the 1st XMM Serendipitous Source Catalog compiled by the XMM Science Center to identify low-z X-ray selected normal galaxy candidates. Our sample covers a total area of ~6deg^2 to the 0.5-2keV limit 1e-15cgs. A total of 23 sources are selected on the basis of low X-ray-to-optical flux ratio logfx/fopt<-2, soft X-ray spectral properties and op

C. G. Bassa, M. H. van Kerkwijk, S. R. Kulkarni

We present optical and near-infrared observations with Keck of the binary millisecond pulsar PSR J0751+1807. We detect a faint, red object - with R=25.08+-0.07, B-R=2.5+-0.3, and R-I=0.90+-0.10 - at the celestial position of the pulsar and argue that it is the white dwarf companion of the pulsar. The colours are the reddest among all known white dwarfs, and

E. Sturm, G. Hasinger, I. Lehmann, V. Mainieri

We have performed a spectroscopic study of 7 Type 2 QSOs using the mid-infrared spectrometer IRS on board the Spitzer Space Telescope. These are (to our knowledge) the first mid-IR spectra of X-ray selected QSO2s taken. The objects have been selected according to their high intrinsic luminosities and column densities in the X-rays. Their spectra strongly dif

S. Fernandez-Cerezo, C. M. Gutierrez, R. Rebolo, R. A. Watson

(Abridged) We present the analysis of the first 18 months of data obtained with the COSMOSOMAS experiment at the Teide Observatory (Tenerife). Three maps have been obtained at 12.7, 14.7 and 16.3 GHz covering 9000 square degrees each with a resolution of ~1 degree and with sensitivities 49, 59 and 115 muK per beam respectively. These data in conjuction with

R. A. Windhorst, S. H. Cohen, A. N. Straughn, R. E. Ryan

In this paper, we address whether the growth of supermassive black-holes has kept pace with the process of galaxy assembly. For this purpose, we first searched the Hubble Ultra Deep Field (HUDF) for &#34;tadpole galaxies&#34;, which have a knot at one end and an extended tail. They appear dynamically unrelaxed -- presumably early-stage mergers -- and make up

Tsevi Mazeh, Omer Tamuz, Pierre North

In the first paper of this series we presented EBAS, a new fully automated algorithm to analyse the lightcurves of eclipsing binaries, based on the EBOP code. Here we apply the new algorithm to the whole sample of 2580 binaries found in the OGLE LMC photometric survey and derive the orbital elements for 1931 systems. To obtain the statistical properties of t

Simon L. Morris, Buell T. Jannuzi

We investigate the relative distribution of the gaseous contents of the Universe (as traced by a sample of Lyman alpha (lya) absorbers), and the luminous baryonic matter (as traced by a redshift survey of galaxies in the same volume searched for lya absorbers), along 16 lines-of-sight (LOS) between redshifts 0 and 1. Our galaxy redshift survey was made with

Omer Tamuz, Tsevi Mazeh, Pierre North

We present a new algorithm -- Eclipsing Binary Automated Solver (EBAS), to analyse lightcurves of eclipsing binaries. The algorithm is designed to analyse large numbers of lightcurves, and is therefore based on the relatively fast EBOP code. To facilitate the search for the best solution, EBAS uses two parameter transformations. Instead of the radii of the t

M. Limongi, A. Chieffi

We present the basic properties of the yields of our latest set of presupernova evolution and explosive nucleosynthesis of massive stars in the range between 11 and 120 Msun having solar and zero metallicity.

Frederic Zagury

This paper presents an analysis of a series of spectra in the Red Rectangle nebula. Only the reddest part of the spectra can safely be attributed to light from the nebula, and indicates Rayleigh scattering by the gas, in conformity with the large angles of scattering involved and the proximity of the star. In the blue, light from HD44179, refracted or scatte

Frederic Zagury

This paper examines the variations, because of atmospheric extinction, of broad-band visible spectra, obtained from long-slit spectroscopy, in the vicinity of some stars, nebulae, and one faint galaxy.

Roy R. Gal

This chapter provides an overview of past and present techniques for optical detection of galaxy clusters. It follows the progression of cluster detection techniques through time, allowing readers to understand the development of the field while explaining the variety of data and methodologies applied. Within each section we describe the datasets and algorit

Hum Chand, Raghunathan Srianand, Patrick Petitjean, Bastien Aracil

We present a detailed analysis of a very high resolution (R\approx 112,000) spectrum of the quasar HE 0515-4414 obtained using the High Accuracy Radial velocity Planet Searcher (HARPS) mounted on the ESO 3.6 m telescope at the La Silla observatory. The HARPS spectrum, of very high wavelength calibration accuracy (better than 1 mÅ), is used to search for poss

A. ud-Doula, R. H. D. Townsend, S. P. Owocki

We present 2D MHD simulations of the radiatively driven outflow from a rotating hot star with a dipole magnetic field aligned with the star&#39;s rotation axis. We focus primarily on a model with moderately rapid rotation (half the critical value), and also a large magnetic confinement parameter, $η_{\ast} \equiv B_{\ast}^2 R_{\ast}^{2} / \dot{M} V_{\infty}

The BABAR Collaboration, B. Aubert

We measure the branching ratios of the Cabibbo-suppressed decays $Λ^+_c$ $\to$ $Λ$ $K^+$ and $Λ^+_c$ $\to$ $Σ^{0}$ $K^+$ %(measured with improved accuracy). relative to the Cabibbo-favored decay modes $Λ^+_c$ $\to$ $Λ$ $π^+$ and $Λ^+_c$ $\to$ $Σ^{0}$ $π^+$ to be $ 0.044 \pm 0.004 (\textnormal{stat.}) \pm 0.003 \ (\textnormal{syst.})$ and $ 0.039 \pm 0.005 (\

Tiago C. Ribeiro, Xiao-Gang Wen

In the generalized-tJ model the effect of the large local Coulomb repulsion is accounted for by restricting the Hilbert space to states with at most one electron per site. In this case the electronic system can be viewed in terms of holes hopping in a lattice of correlated spins, where holes are the carriers doped into the half-filled Mott insulator. To expl

J. L. M. Barbosa, G. Pacelli Bessa, J Fabio Montenegro

We extend the Chern-Heinz inequalities about mean curvature and scalar curvature of graphs of $C^{2}$-functions to leaves of transversally oriented codimension one $C^{2}$-foliations of Riemannian manifolds. That extends partially Salavessa&#39;s work on mean curvature of graphs and generalize results of Barbosa-Kenmotsu-Oshikiri \cite{barbosa-kenmotsu-Oshik