April 2006 arXiv papers — page 38

Vincent Lemaire

The aim of this paper is to study the behavior of the weighted empirical measures of the decreasing step Euler scheme of a one-dimensional diffusion process having multiple invariant measures. This situation can occur when the drift and the diffusion coefficient are vanish simultaneously. As a first step, we give a brief description of the Feller's class

Jean-Francois Dat

Harris and Taylor proved that the supercuspidal part of the cohomology of the Lubin-Tate tower realizes both the local Langlands and Jacquet-Langlands correspondences, as conjectured by Carayol. Recently, Boyer computed the remaining part of the cohomology and exhibited two defects : first, the representations of GL\_d which appear are of a very particular a

Florentin Smarandache

Over 300 sequences and many unsolved problems and conjectures related to them are presented herein together with theorems corollaries, formulae, examples, mathematical criteria, etc. (about integer sequences, numbers, quotients, residues, exponents, sieves, pseudo-primes/squares/cubes/factorials, almost primes, mobile periodicals, functions, tables, prime/sq

Jérôme Droniou, Robert Eymard

We present a new finite volume scheme for anisotropic heterogeneous diffusion problems on unstructured irregular grids, which simultaneously gives an approximation of the solution and of its gradient. In the case of simplicial meshes, the approximate solution is shown to converge to the continuous ones as the size of the mesh tends to 0, and an error estimat

Takashi Hashimoto

It is known that the universal enveloping algebra of the orthogonal Lie algebra of size even has a central element expressed in terms of Pfaffian of a certain matrix alternating along the anti-diagonal (which we call anti-alternating for short) whose entries are in the univerasal enveloping algebra. In this paper, we establish minor summation formulae of Pfa

D. I. Dais, M. Henk, G. M. Ziegler

For which finite subgroups G of SL(r,C), r \geq 4, are there crepant desingularizations of the quotient space C^r/G? A complete answer to this question (also known as "Existence Problem" for such desingularizations) would classify all those groups for which the high-dimensional versions of McKay correspondence are valid. In the paper we consider this

Hiroshige Kajiura, Kyoji Saito, Atsushi Takahashi

We study a triangulated category of graded matrix factorizations for a polynomial of type ADE. We show that it is equivalent to the derived category of finitely generated modules over the path algebra of the corresponding Dynkin quiver. Also, we discuss a special stability condition for the triangulated category in the sense of T. Bridgeland, which is natura

E. Antonyan, J. A. Harvey, S. Jensen, D. Kutasov

We study a configuration of D-branes in string theory that is described at low energies by a four-dimensional field theory with a dynamically broken chiral symmetry. In a certain region of the parameter space of the brane configuration the low-energy theory is a non-local generalization of the Nambu-Jona-Lasinio (NJL) model. This vector model is exactly solv

Jan Kotanski

N-Reggeized gluon states in Quantum Chromodynamics are described by BKP equation. In order to solve this equation for N>3 particles the Q-Baxter operator method is used. Spectrum of the integrals of motion of the system exhibits a complicated structure. In this work we consider the case with N=4 Reggeons where complicated relations between q_3-spectrum and q

Shijong Ryang

For the \kappa-symmetry gauge fixed superstring action in AdS_5 x S^5 we consider the fermionic fluctuations over a circular bosonic string background with two angular momenta and two winding numbers in S^5. The SU(2)-type redefinitions of fermionic fields and the first-string limit generate a truncated fermionic action for the SU(1|2) sector. It is expresse

Yuichi Hoshino

We discuss the structure of the dressed fermion propagator in unquenched QED3 based on spectral function of photon.In this approximation infrared divergences that appeared in quenched case turns out to be soft.The dimension full coupling constant naturally appears as an infrared mass scale in this case.We find the reliable results for the effects of vacuum p

J. M. Isidro

We prove that invariance of a quantum theory under the semiclassical vs. strong-quantum duality $S/\hbar\longleftrightarrow\hbar/S$, where S is the classical action, is equivalent to noncommutativity (of the Heisenberg-algebra type) of the coordinates of the space on which S is defined. We place these facts in correspondence with gerbes and Neveu-Schwarz B-f

S. Geer

In 2004, motivated by the recent exciting developments in neutrino physics, the Fermilab Long Range Planning Committee identified a new high intensity Proton Driver as an attractive option for the future. At the end of 2004 the APS ``Study on the Physics of Neutrinos'' concluded that the future U.S. neutrino program should have, as one of its compone

I. Sotsky

Detailed numerical analysis of four charged leptons photoproduction in frame of standard theory of electroweak interaction is presented. Total and differential cross sections are obtained and investigated using the Monte-Carlo method of numerical integration. Different energies of initial photons (60-2000 GeV in c.m.s.) as well as the definite and averaged s

J. Blümlein, V. Ravindran

We calculate the Mellin moments of the $O(α_s^2)$ coefficient functions for the unpolarized and polarized fragmentation functions. They can be expressed in terms of multiple finite harmonic sums of maximal weight {\sf w = 4}. Using algebraic and structural relations between harmonic sums one finds that besides the single harmonic sums only three basic sums a

D. Ebert, R. N. Faustov, V. O. Galkin

Semileptonic decays of heavy baryons consisting of one heavy (Q=b,c) and two light (q=u,d,s) quarks are considered in the heavy-quark--light-diquark approximation. The relativistic quasipotential equation is used for obtaining masses and wave functions of both diquarks and baryons within the constituent quark model. The weak transition matrix elements are ex

David A. Kosower

Precision computations of QCD and QCD+electroweak emission scattering processes will play an important role in understanding experimental data from the LHC, and thereby in uncovering new physics beyond the Standard Model. Recent years have seen substantial progress in expanding our ability to perform and implement such calculations. I discuss several differe

Houri Ziaeepour

We present a quintessence model for the dark energy in which the quintessence scalar field is produced by the decay of a super heavy dark matter and gradually condensate to a classical scalar field. This model can explain both the smallness and the latest observations by WMAP for the equation of state of the dark energy which has $w \sim -1.06$. We review bo

D. Aristizabal Sierra, Diego Restrepo

We consider the version of the Zee model where both Higgs doublets couple to leptons. Within this framework we study charged Higgs decays. We focus on a model with minimal number of parameters consistent with experimental neutrino data. Using constraints from neutrino physics we (i) discuss the reconstruction of the parameter space of the model using the lep

N. Barnea, J. Vijande, A. Valcarce

We present a generalization of the hyperspherical harmonic formalism to study systems made of quarks and antiquarks of the same flavor. This generalization is based on the symmetrization of the $N-$body wave function with respect to the symmetric group using the Barnea and Novoselsky algorithm. The formalism is applied to study four-quark systems by means of

T. Shishkina, I. Sotsky

We present the matrix element of gamma gamma ->4l process with four charge particles in final state. The constructions are performed in frame of Standard Model of electroweak interaction using the helicity amplitude method . Every possible polarization state of initial and final particles are considered and analyzed.

Yusuke Taniguchi

Finite volume renormalization scheme is one of the most fascinating scheme for non-perturbative renormalization on lattice. By using the step scaling function one can follow running of renormalized quantities with reasonable cost. It has been established the Schroedinger functional is very convenient to define a field theory in a finite volume for the renorm

BES Collaboration

We report on a search for the decays J/Psi --> Ds- e+ nu_e + c.c., J/Psi --> D- e+ nu_e + c.c., and J/Psi --> D0bar e+ e- + c.c. in a sample of 5.8 * 10^7 J/Psi events collected with the BESII detector at the BEPC. No excess of signal above background is observed, and 90% confidence level upper limits on the branching fractions are set: B(J/Psi --> Ds- e+ nu

P. Rossi

The study of the electromagnetic form factors of the nucleon in both the space-like and time-like domains plays a key role for the understanding of the internal structure and dynamics of this basic building block of the matter. Form factors are also necessary for the interpretation of many other measurements in reactions involving nucleons. In spite of being

David Bateman, Andy Adler

There are many classes of mathematical problems which give rise to matrices, where a large number of the elements are zero. In this case it makes sense to have a special matrix type to handle this class of problems where only the non-zero elements of the matrix are stored. Not only does this reduce the amount of memory to store the matrix, but it also means

C. R. Willis

In Ref.[1] [Phys. Rev. B. {\bf 42}, 2290 (1990)] we used a rigorous projection operator collective variable formalism for nonlinear Klein-Gordon equations to prove the continuum Sine-Gordon (SG) equation has a long lived quasimode whose frequency $ω_s$= 1.004 $Γ_0$ is in the continuum just above the lower phonon band edge with a lifetime ($1/τ_s$) = 0.0017 $

Vasily E. Tarasov

We consider dynamical systems that are described by fractional power of coordinates and momenta. The fractional powers can be considered as a convenient way to describe systems in the fractional dimension space. For the usual space the fractional systems are non-Hamiltonian. Generalized transport equation is derived from Liouville and Bogoliubov equations fo

T. M. Guozden, E. A. Jagla

We analyze a piece-wise linear elastic model for the propagation of a crack in a stripe geometry under mode III conditions, in the absence of dissipation. The model is continuous in the propagation direction and discrete in the perpendicular direction. The velocity of the crack is a function of the value of the applied strain. We find analytically the value

Tu Yu-Song, A. O. Sousa, Kong Ling-Jiang, Liu Mu-Ren

We analyze the Sznajd opinion formation model, where a pair of neighboring individuals sharing the same opinion on a square lattice convince its six neighbors to adopt their opinions, when a fraction of the individuals is updated according to the usual random sequential updating rule (asynchronous updating), and the other fraction, the simultaneous updating

Janina Marciak-Kozlowska, Miroslaw Kozlowski

In this paper the continuous laser beam interaction with matter is investigated. The velocities of the thermal propagation are calculated. It is shown that for the value of the product, omega x tau>1, omega is the angular frequency of the laser beam and tau is the relaxation time for thermal phenomena, the Heisenberg uncertainty, VT>h/2, is fulfilled, V is t

Silvio Franz

This paper discusses the dynamical properties of $p$-spin models with Kac kind interactions. For large but finite interaction range $R$ one finds two different time scales for relaxation. A first relaxation roughly independent of $R$ where the system is confined to limited regions of the configuration space and an $R$ dependent time scale where the system is

B. Fisher, J. Genossar, K. B. Chashka, L. Patlagan

We report on pulsed and DC I-V characteristics of polycrystalline samples of three charge-ordered manganites, Pr_{2/3}Ca_{1/3}MnO_3, Pr_{1/2}Ca_{1/2}MnO_3, Bi_{1/2}Sr_{1/2}MnO_3 and of a double-perovskite Sr_2MnReO_6, in a temperature range where their ohmic resistivity obeys the Efros-Shklovskii variable range hopping relation. For all samples, the DC I(V)

Maria Sotiropoulou, Julian Oberdisse, Georgios Staikos

The hydrogen-bonding interpolymer complexation between poly(acrylic acid) (PAA) and the poly(N,N-dimethylacrylamide) (PDMAM) side chains of the negatively charged graft copolymer poly(acrylic acid-co-2-acrylamido-2-methyl-1-propane sulfonic acid)-graft-poly(N, N dimethylacrylamide) (P(AA-co-AMPSA)-g-PDMAM), containing 48 wt % of PDMAM, and shortly designated

Naoum Karchev, Vasil Michev

The double exchange model with on-site Coulomb repulsion is considered. Schwinger-bosons representation of the localized spins is used and two spin-singlet Fermion operators are introduced. In terms of the new Fermi fields the on-site Hund's interaction is in a diagonal form and the true magnons of the system are identified. The singlet fermions can be u

S. Pasquali, J. K. Percus

We describe a linear homopolymer using a Grand Canonical ensemble formalism, a statistical representation that is very convenient for formal manipulations. We investigate the properties of a system where only next neighbor interactions and an external, confining, field are present, and then show how a general pair interaction can be introduced perturbatively

Denitsa Alamanova, Valeri G. Grigoryan, Michael Springborg

Using the Embedded Atom Method as developed by Voter and Chen in combination with the {\it variable metric/quasi-Newton} and our own {\it Aufbau/Abbau} methods, we have identified the three most stable isomers of Au$_N$ clusters with $N$ up to 150. For the first time clusters with tetrahedral symmetry are found to form the ground states of Au$_{17}$ and Au$_

Denitsa Alamanova, Yi Dong, Habib ur Rehman, Michael Springborg

We study the structure and energetics of Au$_N$ clusters by means of parameter-free density-functional calculations ($N\le 8$), jellium calculations ($N\le 60$), embedded-atom calculations ($N\le 150$), and parameterized density-functional calculations ($N\le 40$) in combination with different methods for determining the structure of the lowest total energy.

Matthias E. Möbius

This paper investigates a clustering instability of a freely falling granular jet composed of 100 micron glass spheres. The granular flow out of a circular nozzle starts out spatially uniform and then, further downstream, breaks up into well defined clusters. The role of air is investigated in this phenomenon by changing the ambient air pressure down to 1/50

Artur Widera, Fabrice Gerbier, Simon Foelling, Tatjana Gericke

We report on precision measurements of spin-dependent interaction-strengths in the 87Rb spin-1 and spin-2 hyperfine ground states. Our method is based on the recent observation of coherence in the collisionally driven spin-dynamics of ultracold atom pairs trapped in optical lattices. Analysis of the Rabi-type oscillations between two spin states of an atom p

D. van der Marel, F. Carbone, A. B. Kuzmenko, E. Giannini

We present novel infrared optical conductivity data on the three layer high Tc superconductor Bi2Sr2Ca2Cu3O10 at optimal doping. We extend the analysis of an earlier publication, providing a universal scaling function sigma(omega,T)=g(omega/T)/T for the optical conductivity. In the present manuscript we obtain a good scaling collapse of the experimental curv

M. Rosvall, K. Sneppen

In this paper we quantify our limited information horizon, by measuring the information necessary to locate specific nodes in a network. To investigate different ways to overcome this horizon, and the interplay between communication and topology in social networks, we let agents communicate in a model society. Thereby they build a perception of the network t

Bimalendu Deb

We describe pair-correlation inherent in the structure of many-particle ground state of quantum gases, namely, Bose Einstein condensate and Cooper-paired Fermi superfluid of atomic gases. We make a comparative study on the pair-correlation properties of these two systems. We discuss how to probe this pair-correlation by stimulated light scattering. This intr

E. Sola, J. Casulleras, J. Boronat

Small and stable drops of 3He atoms can only exist above a minimum number of particles, due to the combination of the 3He atom Fermi statistics and its light mass. An accurate estimation of this minimum number using microscopic theory has been difficult due to the inhomogeneous and fermionic nature of these systems. We present a diffusion Monte Carlo calcula

T. Fujima, H. Frusawa, H. Minamikawa, K. Ito

By the combination of optical tweezer manipulation and digital video microscopy, the flexural rigidity of single glycolipid "nano" tubes has been measured below the transition temperature at which the lipid tubules are transformed into vesicles. Consequently, we have found a clear reduction of the rigidity obviously before the transition as temperatu

N. I. Cade, M. Hadjipanayi, R. Roshan, A. C. Maciel

Modulation-doped GaAs v-groove quantum wires (QWRs) have been fabricated with novel electrical contacts made to two-dimensional electron-gas (2DEG) reservoirs. Here, we present longitudinal photocurrent (photoconductivity/PC) spectroscopy measurements of a single QWR. We clearly observe conductance in the ground-state one-dimensional subbands; in addition, a

Sugata Ray, D. D. Sarma, R. Vijayaraghavan

We investigate the nature and origin of the metal-insulator transition in Sr2Ru1-xTixO4 as a function of increasing Ti content (x). Employing detailed core, valence, and conduction band studies with x-ray and ultraviolet photoelectron spectroscopies along with Bremsstrahlung isochromat spectroscopy, it is shown that a hard gap opens up for Ti content greater

Hiroki Yamazaki, Nic Shannon, Hidenori Takagi

In order to clarify the influence of ferromagnetism on superconductivity through a normal metal layer, the superconducting properties of epitaxial Nb(110)/Au(111)/Fe(110) trilayers were studied as a function of the thickness tAu of the intervening Au layer. Structural characterization of the samples revealed sharp interfaces, almost free from roughness. A st

Michael Galperin, Abraham Nitzan, Mark A. Ratner

The effect of electron-phonon coupling on the current noise in a molecular junction is investigated within a simple model. The model comprises a 1-level bridge representing a molecular level that connects between two free electron reservoirs and is coupled to a vibrational degree of freedom representing a molecular vibrational mode. The latter in turn is cou

X. D. Pi, O. H. Y. Zalloum, A. P. Knights, P. Mascher

Current-voltage measurements have been made at room temperature on a Si-rich silicon oxide film deposited via Electron-Cyclotron Resonance Plasma Enhanced Chemical Vapor Deposition (ECR-PECVD) and annealed at 750 - 1000$ ^\circ$C. The thickness of oxide between Si quantum dots embedded in the film increases with the increase of annealing temperature. This le

Chih-Yuan Tseng

Model or variable selection is usually achieved through ranking models according to the increasing order of preference. One of methods is applying Kullback-Leibler distance or relative entropy as a selection criterion. Yet that will raise two questions, why uses this criterion and are there any other criteria. Besides, conventional approaches require a refer

Stefan Frank, Per Arne Rikvold

The influence of lateral adsorbate diffusion on the dynamics of the first-order phase transition in a two-dimensional Ising lattice gas with attractive nearest-neighbor interactions is investigated by means of kinetic Monte Carlo simulations. For example, electrochemical underpotential deposition proceeds by this mechanism. One major difference from adsorpti

G. Mannarini, R. Zimmermann

The excitonic absorption spectrum for a disordered quantum well in presence of exciton-acoustic phonon interaction is treated beyond the Markov approximation. Realistic disorder exciton states are taken from a microscopic simulation, and the deformation potential interaction is implemented. The exciton Green's function is solved with a self energy in sec

Eric Bertin, Olivier Dauchot, Michel Droz

We show that intensive thermodynamic parameters associated to additive conserved quantities can be naturally defined from a statistical approach in far-from-equilibrium steady-state systems, under few assumptions, and without any detailed balance requirement. It may apply, e.g., to dissipative systems like granular gases where volume or mass is still conserv

A. Greilich, R. Oulton, S. Yu. Verbin, R. V. Cherbunin

A key to achieving ultra-long electron spin memory in quantum dots (QDs) at 0~$T$ is the polarization of the nuclei, such that the electron spin is stabilized along the nuclear magnetic field. We demonstrate that spin-polarized electrons in n-doped QDs align the nuclear field via the hyperfine interaction. A feedback onto the electrons occurs, leading to sta

Alexander Weisse, Gerhard Wellein, Andreas Alvermann, Holger Fehske

Efficient and stable algorithms for the calculation of spectral quantities and correlation functions are some of the key tools in computational condensed matter physics. In this article we review basic properties and recent developments of Chebyshev expansion based algorithms and the Kernel Polynomial Method. Characterized by a resource consumption that scal

R. Takayama, T. Hoshi, T. Sogabe, S. -L. Zhang

A linear algebraic method named the shifted conjugate-orthogonal-conjugate-gradient method is introduced for large-scale electronic structure calculation. The method gives an iterative solver algorithm of the Green's function and the density matrix without calculating eigenstates.The problem is reduced to independent linear equations at many energy point

Joshua Pepper, Chris Burke

The Survey for Transiting Extrasolar Planets in Stellar Systems (STEPSS) project is a search for planetary transits in open clusters. In this paper, we analyze the STEPSS observations of the open cluster NGC 1245 to determine the variable star content of the cluster. Out of 6787 stars observed with V < 22, of which ~870 are cluster members, we find 14 stars

S. P. Rajaguru, A. C. Birch, T. L. Duvall, M. J. Thompson

It is well known that the observed amplitude of solar oscillations is lower in sunspots than in quiet regions of the Sun. We show that this local reduction in oscillation amplitudes combined with the phase-speed filtering procedure in time-distance helioseismic analyses could be a source of systematic errors in the range of 5 - 40% in the measured travel-tim

Adrienne M. Juett, Deepto Chakrabarty

We present the high-resolution Chandra X-ray Observatory persistent (non-dip) spectrum of 4U 1916-05 which revealed narrow absorption lines from hydrogenic neon, magnesium, silicon, and sulfur, in addition to the previous identified hydrogenic and helium-like iron absorption lines. This makes 4U 1916-05 only the second of the classical X-ray dipper systems t

Sudip Bhattacharyya, Tod E. Strohmayer

We analyse archival Rossi X-Ray Timing Explorer (RXTE) proportional counter array (PCA) data of thermonuclear X-ray bursts from the 2002 outburst of the accreting millisecond pulsar SAX J1808.4-3658. We present evidence of nonmonotonic variations of oscillation frequency during burst rise, and correlations among the time evolution of the oscillation frequenc

C. Rodriguez, G. B. Taylor, R. T. Zavala, A. B. Peck

We report on the discovery of a supermassive binary black hole system in the radio galaxy 0402+379, with a projected separation between the two black holes of just 7.3 pc. This is the closest black hole pair yet found by more than two orders of magnitude. These results are based upon recent multi-frequency observations using the Very Long Baseline Array (VLB

Dawn K. Erb, Charles C. Steidel, Alice E. Shapley, Max Pettini

We present analysis of the near-infrared spectra of 114 rest-frame UV-selected star-forming galaxies at z~2. By combining the H-alpha spectra with photometric measurements from observed 0.3--8 micron, we assess the relationships between kinematics, dynamical masses, inferred gas fractions, and stellar masses and ages. The H-alpha line widths give a mean dyna

Steven Furlanetto

We consider the evolution of the sky-averaged 21 cm background during the early phases of structure formation. Using simple analytic models, we calculate the thermal and ionization histories, assuming that stellar photons dominate the radiation background. The resulting 21 cm spectra can constrain the properties of the first generations of stars and quasars.

C. Aerts, P. De Cat, R. Kuschnig, J. M. Matthews

We report the discovery of a new slowly pulsating B (SPB) star, with the largest number of detected frequencies to date by more than a factor of three, based on 37 days of MOST (Microvariability & Oscillations of STars) satellite guide star photometry. The star HD 163830 (V = 9.3, B5II/III) varies in twenty detected frequencies in the range $0.035 - 1.06$ d$

Dinah M. Allen, Beatriz Barbuy

We present a detailed analysis of 26 barium stars, including dwarf barium stars, providing their atmospheric parameters (Teff, log g, [Fe/H], vt) and elemental abundances. We aim at deriving gravities and luminosity classes of the sample stars, in particular to confirm the existence of dwarf barium stars. Accurate abundances of chemical elements were derived

M. Catelan

The importance of horizontal branch and RR Lyrae stars is discussed in the context of cosmological arguments for the formation of the Galactic halo and its satellite dwarf galaxies. It is shown, in particular, that the Galactic halo globular cluster system cannot have formed from the accretion of ``protogalactic fragments&#39;&#39; resembling the very early

Bryan M. Johnson, Charles F. Gammie

We consider the formation and evolution of vortices in a hydrodynamic shearing-sheet model. The evolution is done numerically using a version of the ZEUS code. Consistent with earlier results, an injected vorticity field evolves into a set of long-lived vortices, each of which has a radial extent comparable to the local scale height. But we also find that th

Paolo A. Mazzali, Philipp Podsiadlowski

A variation of the relative content of (54Fe+58Ni) versus 56Ni may be responsible for the observed scatter of Type Ia Supernovae (SNe Ia) about a mean relation between their intrinsic brightness and the shape of their light curve. Synthetic light curves are computed of parametrised Chandrasekhar-mass explosion models of constant kinetic energy, where the eje

J. -L. Monin, C. J. Clarke, L. Prato, C. McCabe

The formation of a binary system surrounded by disks is the most common outcome of stellar formation. Hence studying and understanding the formation and the evolution of binary systems and associated disks is a cornerstone of star formation science. Moreover, since the components within binary systems are coeval and the sizes of their disks are fixed by the

L. Origlia, E. Valenti, R. M. Rich, F. R. Ferraro

We report abundance analysis for 6 M giant members of the old open cluster NGC6791, based on infrared spectroscopy (1.5-1.8 micron) at R=25,000, using the NIRSPEC spectrograph at the Keck II telescope. We find the iron abundance <[Fe/H]>= +0.35 +/- 0.02$, confirming the super solar metallicity of this cluster derived from optical medium-high resolution spect

Philip Kaaret, Melanie G. Simet, Cornelia C. Lang

In 240 days of X-ray monitoring of M82, we have discovered an X-ray periodicity at $62.0 \pm 2.5$ days with a peak to peak amplitude corresponding to an isotropic luminosity of $2.4 \times 10^{40} \rm erg s^{-1}$ in M82 and an X-ray flare reaching a peak luminosity of $9.8 \times 10^{40} \rm erg s^{-1}$. The periodicity and flare likely originate from the ul

Nayra Rodriguez-Eugenio, Kai G. Noeske, Jose Acosta-Pulido, Rafael Barrena

We present preliminary results of H_alpha near-infrared spectroscopy of six galaxies with redshifts z ~ 1 drawn from the DEEP2 Galaxy Redshift Survey. The spectra have been taken with the multi-slit mode of LIRIS (Long-slit Intermediate Resolution Infrared Spectrograph) installed at the 4.2-m William Herschel Telescope. This is a pilot study for a larger pro

M. Demianski, E. Piedipalumbo, C. Rubano, C. Tortora

We consider scalar tensor theories of gravity assuming that the scalar field is non minimally coupled with gravity. We use this theory to study evolution of a flat homogeneous and isotropic universe. In this case the dynamical equations can be derived form a point like Lagrangian. We study the general properties of dynamics of this system and show that for a

Eduardo Bravo, Domingo Garcia-Senz

We describe a mechanism by which a failed deflagration of a Chandrasekhar-mass carbon-oxygen white dwarf can turn into a successful thermonuclear supernova explosion, without invoking an ad hoc high-density deflagration-detonation transition. Following a pulsating phase, an accretion shock develops above a core of 1 M_sun composed of carbon and oxygen, induc

E. Moulin, J. F. Macias-Perez, F. Mayet, C. Winkelmann

The analysis of the time ordered data of Dark Matter experiments is becoming more and more challenging with the increase of sensitivity in the ongoing and forthcoming projects. Combined with the well-known level of background events, this leads to a rather high level of pile-up in the data. Ionization, scintillation as well as bolometric signals present comm

Gajendra Pandey, Bacham E. Reddy

Abundance analysis of the cool extreme helium (EHe) star LSS 3378 is presented. The abundance analysis is done using LTE line formation and LTE model atmospheres constructed for EHe stars. The atmosphere of LSS 3378 shows evidence of H-burning, He-burning, and s-process nucleosynthesis. The derived abundances of iron-peak and alpha-elements indicate absence

Burkhard Fuchs, Stefanie Phleps

The general relativistic model of Cooperstock & Tieu, which attempts to fit rotation curves of spiral galaxies without invoking dark matter, is tested empirically using observations of the Milky Way. In particular, predictions for the mass density in the solar neighbourhood and the vertical density distribution at the position of the Sun are compared with ob

Ingo Lohmar, Joachim Krug

A prominent chemical reaction in interstellar clouds is the formation of molecular hydrogen by recombination, which essentially takes place on dust grain surfaces. Analytical approaches to model such a system have hitherto neglected the spatial aspects of the problem by employing a simplistic version of the sweeping rate of reactants. We show how these aspec

Chandreyee Sengupta, Ramesh Balasubramanyam

Gas deficiency in cluster spirals is well known and ram-pressure stripping is considered the main gas removal mechanism. In some compact groups too gas deficiency is reported. However, gas deficiency in loose groups is not yet well established. Lower dispersion of the member velocities and the lower density of the intra-group medium in small loose groups fav

Zhonghui Fan, Xinwu Cao, Minfeng Gu

There is clear evidence that the $γ$-ray emission from active galactic nuclei (AGNs) is attributed to the inverse Compton scatterings in the relativistic blobs near the massive black holes. If the soft seed photons are from the regions outside the blobs, a linear relation between $(νF_{ν,γ}/νF_{ν, \rm syn} u^{*})^{1/(1+α)}$ and Doppler factor $δ$ is expected

G. Brodin M. Marklund, L. Stenflo, P. K. Shukla

This paper is withdrawn because it is a duplicate of astro-ph/0601311

Frank H. Lutz

We give a complete enumeration of all combinatorial 3-manifolds with 10 vertices: There are precisely 247882 triangulated 3-spheres with 10 vertices as well as 518 vertex-minimal triangulations of the sphere product $S^2\times S^1$ and 615 triangulations of the twisted sphere product $S^2_\times_S^1$. All the 3-spheres with up to 10 vertices are shellable, b

Sheldon Stone

A short summary is given of the current status of B physics. Reasons for physics beyond the Standard Model are discussed. Constraints on New Physics are given using measurements of B mixing, Bs mixing, and CP violation, along with |Vub. Future goals, and upcoming new experiments are also mentioned.

Theodore H. Geballe, Gertjan Koster

We compare the Tcs found in different families of optimally-doped High-Tc cuprates and find, contrary generally accepted lore, that pairing is not exclusively in the CuO2 layers. Evidence for additional pairing interactions, that take place outside the CuO2 layers, is found in two different classes of cuprates, namely the charge reservoir and the chain layer

L. Amendola, M. Makler, R. R. R. Reis, I. Waga

The equation of state (EOS) in quartessence models interpolates between two stages: $p\simeq 0$ at high energy densities and $p\approx -ρ$ at small ones. In the quartessence models analyzed up to now, the EOS is convex, implying increasing adiabatic sound speed ($c_{s}^{2}$) as the energy density decreases in an expanding Universe. A non-negligible $c_{s}^{2

F. Bassetti, M. Cosentino Lagomarsino, B. Bassetti, P. Jona

In statistical mechanical investigations on complex networks, it is useful to employ random graphs ensembles as null models, to compare with experimental realizations. Motivated by transcription networks, we present here a simple way to generate an ensemble of random directed graphs with, asymptotically, scale-free outdegree and compact indegree. Entries in

Limei Xu, Isaac Ehrenberg, Sergey V. Buldyrev, H. Eugene Stanley

Using molecular dynamics simulations, we study a spherically-symmetric ``two-scale&#39;&#39; Jagla potential with both repulsive and attractive ramps. This potential displays a liquid-liquid phase transition with a positively sloped coexistence line ending at critical point well above the equilibrium melting line. We study the dynamic behavior in the vicinit

E. McCann, K. Kechedzhi, Vladimir I. Fal&#39;ko, H. Suzuura

Due to the chiral nature of electrons in a monolayer of graphite (graphene) one can expect weak antilocalisation and a positive weak-field magnetoresistance in it. However, trigonal warping (which breaks p/-p symmetry of the Fermi line in each valley) suppresses antilocalisation, while inter-valley scattering due to atomically sharp scatterers in a realistic

Martin Beneke, Michael Gronau, Johannes Rohrer, Michael Spranger

The effect of the penguin amplitude on extracting $α$ from CP asymmetries in $B^0\to ρ^+ρ^-$ decays is studied using information on the SU(3)-related penguin amplitude in $B^+\to K^{*0}ρ^+$. Conservative bounds on non-factorizable SU(3) breaking, small amplitudes, and the strong phase difference between tree and penguin amplitudes, are shown to reduce the er

Wenbiao Liu, Kui Xiao, Hongbao Zhang

The Casimir effect has been studied for various quantum fields in both flat and curved spacetimes. As a further step along this line, we provide an explicit derivation of Casimir effect for massless spin-3/2 field with periodic boundary condition imposed in four-dimensional Minkowski spacetime. The corresponding results with Dirichlet and Neumann boundary co

D. Ahn, M. S. Kim

We consider the system of free scalar field, which is assumed to be a two-mode squeezed state from an inertial point of view. This setting allows the use of entanglement measure for continuous variables, which can be applied to discuss free and bound entanglement from the point of view from non-inertial observer.

J. Wildeshaus

This paper has been withdrawn by the author; its content is properly cantained in the paper arXiv:0706.4447, entitled &#34;Pure motives, mixed motives and extensions of motives associated to singular surfaces&#34;, and submitted on June 29, 2007.

N. O. Agasian, Yu. A. Simonov

The Debye mass m_D is computed nonperturbatively in the deconfined phase of QCD, where chromomagnetic confinement is known to be present. The latter defines m_D to be m_D=c_D\sqrt{σ_s}, where c_D \cong 2.06 and σ_s=σ_s(T) is the spatial string tension. The resulting magnitude of m_D(T) and temperature dependence are in good agreement with lattice calculation

L. V. Elnikova

The vesiculation process was examined in the lipid-detergent solution (dimyristoyl-sn-glycero-phoshatidylcholine/octaethylleneglycol n-dodecyl ether/water), using small-angle neutron scattering experiments \cite{1}. When observing vesiculation proceeds from rod-like micelles to unilamellar vesicles, the transformation is induced by jump-like temperature incr

P. H. Chavanis

We determine the mass-radius relation of relativistic white dwarf stars (a self-gravitating degenerate Fermi gas at T=0) in a D-dimensional universe and study the influence of the dimension of space on the laws of physics when we combine quantum mechanics, special relativity and gravity. We exhibit characteristic dimensions D=1, D=2, D=3, D={1\over 2}(3+\sqr

Leonid Lantsman

We analyse two principal approaches to the quantization of physical models worked out to date. There are the Faddeev-Popov &#34;heuristic&#34; approach, based on fixing a gauge in the FP path integrals formalism, and the &#34;fundamental&#34; approach by Dirac based on the constraint-shell reduction of Hamiltonians with deleting unphysical variables. The rel

Mikhail G. Katz

We show that the existence of a nontrivial Massey product in the cohomology ring H^*(X) imposes global constraints upon the Riemannian geometry of a manifold X. Namely, we exhibit a suitable systolic inequality, associated to such a product. This generalizes an inequality proved in collaboration with Y. Rudyak, in the case when X has unit Betti numbers, and

A. V. Lukoyanov, V. V. Mazurenko, V. I. Anisimov, M. Sigrist

We propose FeSb2 to be a nearly ferromagnetic small gap semiconductor, hence a direct analog of FeSi. We find that despite different compositions and crystal structures, in the local density approximation with on-site Coulomb repulsion correction (LDA+U) method magnetic and semiconducting solutions for U=2.6 eV are energetically degenerate similar to the cas

F. Delgado, J. G. Muga, G. Garcia-Calderon

We describe the influence of continuous measurement in a decaying system and the role of the distance from the detector to the initial location of the system. The detector is modeled first by a step absorbing potential. For a close and strong detector, the decay rate of the system is reduced; weaker detectors do not modify the exponential decay rate but supp

L. DiCarlo, Y. Zhang, D. T. McClure, D. J. Reilly

We report simultaneous measurement of shot noise and dc transport in a quantum point contact as a function of source-drain bias, gate voltage, and in-plane magnetic field. Shot noise at zero field exhibits an asymmetry related to the 0.7 structure in conductance. The asymmetry in noise evolves smoothly into the symmetric signature of spin-resolved electron t