November 2008 arXiv papers — page 23

Hirokazu Nishimura

In our previous paper [International Journal of Theoretical Physics, 41 (2002), 1165-1190] we have shown, following the tradition of synthetic differential geometry, that div and rot are uniquely determined, so long as we require that the divergence theorem and the Stokes theorem should hold on the infinitesimal level. In this paper we will simplify the disc

Rim Dib, Victoria M. Kaspi, Fotis P. Gavriil

After three years of no unusual activity, Anomalous X-ray Pulsar 1E 1048.1-5937 reactivated in 2007 March. We report on the detection of a large glitch (Delta(nu)/nu =1.63(2)X~10^{-5}) on 2007 March 26 (MJD 54185.9), contemporaneous with the onset of a pulsed-flux flare, the third flare observed from this source in 10 years of monitoring with the Rossi X-ray

F. Rahaman, M. Kalam, K. A. Rahman

We provide a new model of higher dimensional wormholes supported by phantom energy derived from a scalar field with negative kinetic term. We have shown that the Averaged Null Energy Condition (ANEC) violating phantom energy can be reduced as desired. We have also noticed that dimension of the spacetime plays a crucial role for measuring the ANEC violating m

Elena Shmileva

Consider a symmetric $α$-stable Lévy process with $α\in (1,2)$. We study shifted small ball probabilities for these processes in the uniform topology, when the shift function is an arbitrary continuous function which starts at 0. We obtain the exact rate of decrease for these probabilities including constants. Using these small ball estimates, we obtain a fu

Sajeev Damodarakurup, Marco Lucamarini, Giovanni Di Giuseppe, David Vitali

Decoherence may significantly affect the polarization state of optical pulses propagating in dispersive media because of the unavoidable presence of more than a single frequency in the envelope of the pulse. Here we report on the suppression of polarization decoherence in a ring cavity obtained by properly retooling for photonic qubits the ``bang-bang'&#

Arpita Vajpayee, V. P. S. Awana, G. L. Bhalla, A. K. Nigam

We report the effect of adipic acid (C6H10O4) doping on lattice parameters, microstructure, critical temperature (Tc), current density (Jc), and irreversibility field (Hirr) for MgB2 superconductor. Actual carbon (C) substitution level for boron (B) is estimated to be from 0.40 percent to 2.95 percent for different doping levels. A reduction in Tc from 38.43

Giovanna Carnovale

We classify spherical conjugacy classes in a simple algebraic group over an algebraically closed field of good, odd characteristic.

Alexander Hubbard, Axel Brandenburg

In the mean-field theory of magnetic fields, turbulent transport, i.e. the turbulent electromotive force, is described by a combination of the alpha effect and turbulent magnetic diffusion, which are usually assumed to be proportional respectively to the mean field and its spatial derivatives. For a passive scalar there is just turbulent diffusion, where the

John J. Oh, Wontae Kim

The absorption cross section is studied in the low-frequency region for a propagating scalar field under the warped AdS$_3$ black hole background in the topologically massive gravity. It can be shown that the absorption cross section is significantly deformed by the gravitational Chern-Simons term, which is proportional to the scattering area of black hole w

Andrew Das Arulsamy, Kostya, Ostrikov

Recent controversy on the quantum dots dephasing mechanisms (between pure and inelastic) is re-examined by isolating the quantum dots from their substrate by using the appropriate limits of the ionization energy theory and the quantum adiabatic theorem. When the phonons in the quantum dots are isolated adiabatically from the phonons in the substrate, the ela

Raymond Y. Q. Cai, Valerio Scarani

The lists of bits processed in quantum key distribution are necessarily of finite length. The need for finite-key unconditional security bounds has been recognized long ago, but the theoretical tools have become available only very recently. We provide finite-key unconditional security bounds for two practical implementations of the Bennett-Brassard 1984 cod

S. I. Bastrukov, H. -K. Chang, E. -H. Wu, I. V. Molodtsova

The eigenfrequency problem of fundamental vibrational mode in a highly inhomogeneous star, modeled by self-gravitating mass of viscous liquid with singular density at the center, is considered in juxtaposition with that for Kelvin fundamental mode in the liquid star model with uniform density. Particular attention is given to the difference between spectral

Po-Shen Loh, Oleg Pikhurko, Benny Sudakov

Let P_G(q) denote the number of proper q-colorings of a graph G. This function, called the chromatic polynomial of G, was introduced by Birkhoff in 1912, who sought to attack the famous four-color problem by minimizing P_G(4) over all planar graphs G. Since then, motivated by a variety of applications, much research was done on minimizing or maximizing P_G(q

X. -S. Wang, R. Wong

Using the steepest descent method of Deift-Zhou, we derive locally uniform asymptotic formulas for the Meixner polynomials. These include an asymptotic formula in a neighborhood of the origin, a result which as far as we are aware has not yet been obtained previously. This particular formula involves a special function, which is the uniformly bounded solutio

Nikolai Dokuchaev

The paper presents sufficient conditions of predictability for continuous time processes in deterministic setting. We found that processes with exponential decay on energy for higher frequencies are predictable in some weak sense on some finite time horizon defined by the rate of decay. Moreover, this predictability can be achieved uniformly over classes of

L. P. L. Colombo, E. Pierpaoli, J. R. Pritchard

The Planck satellite is expected to improve the measurement of most cosmological parameters by several factors with respect to current WMAP results. The actual performance may depend upon various aspects of the data analysis. In this paper we analyse the impact of specifics of the data analysis on the actual final results. We also explore the synergies in co

A. Yamaguchi, K. Motoi, A. Hirohata, H. Miyajima

An anomalous Hall effect and rectification of a Hall voltage are observed by applying a radio-frequency (rf) current through a single-layered ferromagnetic wire located on a coplanar waveguide. The components of the magnetization precession, both in and perpendicular to the plane, can be detected via the Hall voltage rectification of the rf current by incorp

Wan-Lei Guo, Li-Ming Wang, Yue-Liang Wu, Yu-Feng Zhou

We propose a dark matter (DM) scenario in an extension of a left-right symmetric model with a gauge-singlet scalar field. The gauge-singlet scalar can automatically become a DM candidate, provided that both P and CP symmetries are only broken spontaneously. Thus no extra discrete symmetries are needed to make the DM candidate stable. After constraining the m

Yi Ling, Qingzhang Wu

The usual Einstein's equations is modified as a one parameter family of equations in the framework of rainbow gravity. In this paper we derive the modified Friedmann-Robertson-Walker (FRW) equations when the cosmological evolution of radiation particles is taken into account. In particular, given some specific dispersion relations, the big bounce solutio

Andrey A. Varlamov, Alexey V. Kavokin

A simple model describing the Nernst-Ettingshausen effect (NEE) in two-component electronic liquids is formulated. The examples considered include graphite, where the normal and Dirac fermions coexist, superconductor in fluctuating regime, with coexisting Cooper pairs and normal electrons, and the inter-stellar plasma of electrons and protons. We give a gene

Mahdi Cheraghchi

We study combinatorial group testing schemes for learning $d$-sparse Boolean vectors using highly unreliable disjunctive measurements. We consider an adversarial noise model that only limits the number of false observations, and show that any noise-resilient scheme in this model can only approximately reconstruct the sparse vector. On the positive side, we t

Gabi Ben Simon, Tobias Hartnick

We show that every continuous homogeneous quasimorphism on a finite-dimensional 1-connected simple Lie group arises as the relative growth of any continuous bi-invariant partial order on that group. More generally we show, that an arbitrary homogeneous quasimorphism can be reconstructed as the relative growth of a partial order subject to a certain sandwich

M A F Gomes, V P Brito, A S O Coelho, C C Donato

When a single long piece of elastic wire is injected trough channels into a confining two-dimensional cavity, a complex structure of hierarchical loops is formed. In the limit of maximum packing density, these structures are described by several scaling laws. In this paper it is investigated this packing process but using plastic wires which give origin to c

CDF Collaboration, T. Aaltonen

We present a measurement of the transverse momentum with respect to the jet axis ($k_{T}$) of particles in jets produced in $p\bar p$ collisions at $\sqrt{s}=1.96$ TeV. Results are obtained for charged particles within a cone of opening angle 0.5 radians around the jet axis in events with dijet invariant masses between 66 and 737 GeV/c$^{2}$. The experimenta

Abdelkader Kara, Christel Leandri, Benedicte Ealet, Hamid Oughaddou

Graphene, a flat monolayer of carbon atoms tightly packed into a two-dimensional honeycomb lattice (a one atom thick graphite sheet), is presently the hottest material in nanoscience and nanotechnology. Its challenging hypothetical reflection in the silicon world is coined silicene; Here, we have demonstrated that the silicon nano-wires self-aligned in a mas

Tomas Oppelstrup, Mikhail Dzugutov

A statistical analysis of the geometries of particle trajectories in the supercooled liquid state is reported. We examine two structurally different fragile glass-forming liquids simulated by molecular dynamics. In both liquids, the trajectories are found to exhibit a long-range localisation distinct from the short-range localisation within the cage of neare

A. J. Aspden, J. B. Bell, M. S. Day, S. E. Woosley

The large range of time and length scales involved in type Ia supernovae (SN Ia) requires the use of flame models. As a prelude to exploring various options for flame models, we consider, in this paper, high-resolution three-dimensional simulations of the small-scale dynamics of nuclear flames in the supernova environment in which the details of the flame st

Paula I. Villar

We calculate the geometric phase of a spin-1/2 particle coupled to an external environment comprising N spin-1/2 particle in the framework of open quantum systems. We analyze the decoherence factor and the deviation of the geometric phase under a nonunitary evolution from the one gained under an unitary one. We show the dependence upon the system's and b

Michal Morayne, Michal Ryszard Wojcik

We present a connected metric space that does not contain any nontrivial separable connected subspace. Our space is a dense connected graph of a function from the real line satisfying Cauchy's equation.

Michelle Caler, Ravi Sheth, Bhuvnesh Jain

We estimate the absolute magnitude distribution of galaxies which lie within about a Mpc of Mg II absorption systems. The absorption systems themselves lie along 1880 lines of sight to QSOs from the Sloan Digital Sky Survey Data Release 3, have rest equivalent widths greater than 0.88 Angstroms, and redshifts between 0.37 < z < 0.82. Our measurement is based

Philip J. Humphrey, Wenhao Liu, David A. Buote

We demonstrate that two approximations to the chi^2 statistic as popularly employed by observational astronomers for fitting Poisson-distributed data can give rise to intrinsically biased model parameter estimates, even in the high counts regime, unless care is taken over the parameterization of the problem. For a small number of problems, previous studies h

Steven Finkelstein, Sangeeta Malhotra, James Rhoads, Nimish Hathi

Recent results have shown that a substantial fraction of high-redshift Lyman alpha galaxies contain considerable amounts of dust. This implies that Lyman alpha galaxies are not primordial, as has been thought in the past. However, this dust has not been directly detected in emission; rather it has been inferred based on extinction estimates from rest-frame u

Anton Zilman

Many biological and artificial transport channels function without direct input of metabolic energy during a transport event and without structural rearrangements involving transitions from a &#39;closed&#39; to an &#39;open&#39; state. Nevertheless, such channels are able to maintain efficient and selective transport. It has been proposed that attractive in

Martin Bojowald

A recently derived inequality on volume fluctuations of a bouncing cosmology, valid for states which are semiclassical long after the bounce, does not restrict pre-bounce fluctuations sufficiently strongly to conclude that the pre-bounce state was semiclassical except in a very weak sense.

K. D. Gordon, C. Bot, E. Muller, K. A. Misselt

The Tail region of the Small Magellanic Cloud (SMC) was imaged using the MIPS instrument on the Spitzer Space Telescope as part of the SAGE-SMC Spitzer Legacy. Diffuse infrared emission from dust was detected in all the MIPS bands. The Tail gas-to-dust ratio was measured to be 1200 +/- 350 using the MIPS observations combined with existing IRAS and HI observ

L. S. Schulman

The puzzle of the thermodynamic arrow of time reduces to the question of how the universe could have had lower entropy in the past. I show that no special entropy lowering mechanism (or fluctuation) is necessary. As a consequence of expansion, at a particular epoch in the history of the universe a state that was near maximum entropy under the dominant short

V. D. Ivashchuk, V. N. Melnikov

A short overview of the billiard approach for cosmological-type models with n Einstein factor-spaces is presented. We start with the billiard representation for pseudo-Euclidean Toda-like systems of cosmological origin. Then we consider cosmological model with multicomponent &#34;perfect-fluid&#34; and cosmological-type model with composite branes. The secon

Y. Charles Li

I shall briefly survey the current status on more rigorous studies of chaos in fluids by focusing along the line of chaos phenotypes: sensitive dependence on initial data, and recurrence.

Mirko Lobino, Dmitry Korystov, Connor Kupchak, Eden Figueroa

The technologies of quantum information and quantum control are rapidly improving, but full exploitation of their capabilities requires complete characterization and assessment of processes that occur within quantum devices. We present a method for characterizing, with arbitrarily high accuracy, any quantum optical process. Our protocol recovers complete kno

Janet C. Tremain

We give some concrete constructions of real equiangular line sets. The emphasis here is on {\em building blocks} for certain angles which are then used to build up larger equiangular line sets. We concentrate on angles greater than or equal to 1/7.

José P. S. Lemos, Oleg B. Zaslavskii

A quasi-black hole, either non-extremal or extremal, can be broadly defined as the limiting configuration of a body when its boundary approaches the body&#39;s quasihorizon. We consider the mass contributions and the mass formula for a static quasi-black hole. The analysis involves careful scrutiny of the surface stresses when the limiting configuration is r

Michael Coons, Klaus Kirsten

A well-known result from Hardy and Ramanujan gives an asymptotic expression for the number of possible ways to express an integer as the sum of smaller integers. In this vein, we consider the general partitioning problem of writing an integer $n$ as a sum of summands from a given sequence $\gL$ of non-decreasing integers. Under suitable assumptions on the se

E. A. Hinds, Stephen M. Barnett

We consider the forces exerted by a pulse of plane-wave light on a single atom. The leading edge of the pulse exerts a dispersive force on the atom, and this modifies the atomic momentum while the atom is enveloped in the light. The standard view of the optical dipole force indicates that red-detuned light should attract the atom towards high intensity. This

M. D. Gray, M. Wittkowski, M. Scholz, E. M. L. Humphreys

We describe a combined dynamic atmosphere and maser propagation model of SiO maser emission in Mira variables. This model rectifies many of the defects of an earlier model of this type, particularly in relation to the infra-red (IR) radiation field generated by dust and various wavelength-dependent, optically thick layers. Modelled masers form in rings with

Avraham Aizenbud

Let X be a smooth real algebraic variety. Let $ξ$ be a distribution on it. One can define the singular support of $ξ$ to be the singular support of the $D_X$-module generated by $ξ$ (some times it is also called the characteristic variety). A powerful property of the singular support is that it is a coisotropic subvariety of $T^*X$. This is the integrability

Iris Gebauer

The ROSAT Galactic wind observations confirm that our Galaxy launches supernova driven Galactic winds with wind speeds of about 150 km/s in the Galactic plane. Galactic winds of this strength are incompatible with current isotropic models for Cosmic Ray transport. In order to reproduce our local CRs in the presence of Galactic winds, charged CRs are required

Alexander S. Kleshchev, Pham Huu Tiep

We classify all triples $(G,V,H)$ such that $SL_n(q)\leq G\leq GL_n(q)$, $V$ is a representation of $G$ of dimension greater than one over an algebraically closed field $\FF$ of characteristic coprime to $q$, and $H$ is a proper subgroup of $G$ such that the restriction $V\dar_{H}$ is irreducible. This problem is a natural part of the Aschbacher-Scott progra

COSY Collaboration

In the first production run of the WASA experiment at COSY, the eta decay into three neutral pions was measured in proton-proton interactions at a proton beam kinetic energy of 1.4 GeV. The Dalitz plot of the three pions was studied using 1.2e5 fully reconstructed events, and the quadratic slope parameter alpha was determined to be -0.027+/-0.008(stat)+/-0.0

Oleg L. Berman, Vladimir S. Boyko, Roman Ya. Kezerashvili, Yurii E. Lozovik

Anomalous far infrared monochromatic transmission through a lattice of Abrikosov vortices in a type-II superconducting film is found and reported. The transmitted frequency corresponds to the photonic mode localized by the defects of the Abrokosov lattice. These defects are formed by extra vortices placed out of the nodes of the ideal Abrokosov lattice. The

A. Eckart, R. Schoedel, M. Garcia-Marin, G. Witzel

We report on a successful, simultaneous observation and modeling of the sub-millimeter to near-infrared flare emission of the Sgr A* counterpart associated with the super-massive black hole at the Galactic center. Our modeling is based on simultaneous observations that have been carried out on 03 June, 2008 using the NACO adaptive optics (AO) instrument at t

L. J. Daniels, Y. Park, T. C. Lubensky, D. J. Durian

We study a quasi-two-dimensional monolayer of granular rods fluidized by a spatially and temporally homogeneous upflow of air. By tracking the position and orientation of the particles, we characterize the dynamics of the system with sufficient resolution to observe ballistic motion at the shortest time scales. Particle anisotropy gives rise to dynamical ani

C. C. Lovekin, R. G. Deupree, M. J. Clement

We have investigated the effects of uniform rotation and a specific model for differential rotation on the pulsation frequencies of 10 \Msun\ stellar models. Uniform rotation decreases the frequencies for all modes. Differential rotation does not appear to have a significant effect on the frequencies, except for the most extreme differentially rotating model

Rolf Schlichenmaier

The penumbra of a sunspot is a fascinating phenomenon featuring complex velocity and magnetic fields. It challenges both our understanding of radiative magneto-convection and our means to measure and derive the actual geometry of the magnetic and velocity fields. In this contribution we attempt to summarize the present state-of-the-art from an observational

D. E. Innes, A. Genetelli, R. Attie, H. E. Potts

Context: The atmosphere of the quiet Sun is controlled by photospheric flows sweeping up concentrations of mixed polarity magnetic field. Along supergranule boundaries and junctions, there is a strong correlation between magnetic flux and bright chromospheric and transition region emission. Aim: The aim is to investigate the relationship between photospheric

Noureddine Djarfour, Tahar Aifa, Kamel Baddari, Abdelhafid Mihoubi

The Elman artificial neural network (ANN) (feedback connection) was used for seismic data filtering. The recurrent connection that characterizes this network offers the advantage of storing values from the previous time step to be used in the current time step. The proposed structure has the advantage of training simplicity by a back-propagation algorithm (s

Valérie Leroy, Dominique Cancellieri, Eric Leoni

The scope of this work was to show the utility of thermal analysis and calorimetric experiments to study the thermal oxidative degradation of Mediterranean scrubs. We investigated the thermal degradation of four species; DSC and TGA were used under air sweeping to record oxidative reactions in dynamic conditions. Heat released and mass loss are important dat

Fleischer Isidore, Giroux Gaston

A semigroup A is an abelian semigroup with identity 0. A set of positives in A is an ordered down-directed set P containing with every r an element r/2 with r/2 + r/2 = r. A continuity space is an abstract set X equipped with a map d : XxX to A satisfying d(x, x) = 0 and d(x, z) d(x, y) + d(y, z). A quasi-uniform space is an abstract set X equipped with a fi

Daniel Gandolfo, Jean Ruiz, Marc Wouts

The Curie-Weiss Potts model is a mean field version of the well-known Potts model. In this model, the critical line $\beta = \beta_c (h)$ is explicitly known and corresponds to a first order transition when $q > 2$. In the present paper we describe the fluctuations of the density vector in the whole domain $\beta \geqslant 0$ and $h \geqslant 0$, including t

Cyril Roberto

We consider Glauber dynamics reversible with respect to Gibbs measures with heavy tails. Spins are unbounded. The interactions are bounded and finite range. The self potential enters into two classes of measures, $κ$-concave probability measure and sub-exponential laws, for which it is known that no exponential decay can occur. We prove, using coercive inequ

Axel Maas

There are, among others, currently two important views on the non-perturbative structure of Yang-Mills theory. One is through topological configurations and one is through Green&#39;s functions, in particular their (asymptotic) infrared behavior. Based on both views, various scenarios for confinement, chiral symmetry breaking and other non-perturbative effec

M. M. Sharma

The breathing-mode isoscalar giant monopole resonance (GMR) is investigated using the generator coordinate method within the relativistic mean-field (RMF) theory. Employing the Lagrangian models of the nonlinear-$σ$ model (NL$σ$), the scalar-vector interaction model (SVI) and the $σ$-$ω$ coupling model (SIGO), we show that each Lagrangian model exhibits a di

T. Herpay, P. Kovács

Pion condensation is studied at one--loop level and nonzero baryochemical potential in the framework of two flavor constituent quark model using the one--loop level optimized perturbation theory for the resummation of the perturbative series. A Landau type of analysis is presented for the investigation of the phase boundary between the pion condensed/non-con

J. C. Gonzalez-Avella, M. G. Cosenza, V. M. Eguiluz, M. San Miguel

We study the collective behavior of nonequilibrium systems subject to an external field with a dynamics characterized by the existence of non-interacting states. Aiming at exploring the generality of the results, we consider two types of models according to the nature of their state variables: (i) a vector model, where interactions are proportional to the ov

Vu the Khoi

In this note, we study the integral of the 1-form $\log x\frac{dy}{y}-\log y\frac{dx}{x}$ over certain plane curves defined by A-polynomials of knots. It is quite surprising that a Chern-Simons type invariant of 3-manifolds, which can be geometrically computed, may be used to get the exact values of those integrals. The arithmetic nature of these integrals i

J. van Eymeren, M. Marcelin, B. Koribalski, R. -J. Dettmar

Abridged. Context. The metal content of dwarf galaxies and the metal enrichment of the intergalactic medium both suggest that mass loss from galaxies is a significant factor for the chemical evolution history of galaxies, in particular of dwarf galaxies. However, no clear evidence of a blow-away in local dwarf galaxies has been found so far. Aims. We therefo

M. Fleck, C. Hueter, D. Pilipenko, R. Spatschek

We develop a description of diffusion limited growth in solid-solid transformations, which are strongly influenced by elastic effects. Density differences and structural transformations provoke stresses at interfaces, which affect the phase equilibrium conditions. We formulate equations for the interface kinetics similar to dendritic growth and study the gro

Pietro Giudice, Ferdinando Gliozzi, Stefano Lottini

We study the behaviour of the monopole at finite temperature in the (2+1)-dimensional lattice gauge theory dual to the percolation model; by exploiting the correspondences to statistical systems, we possess powerful tools to evaluate the monopole mass both above and below the critical temperature with high-precision Monte Carlo simulations.

Davide Sarchi, Michiel Wouters, Vincenzo Savona

A general theory of polariton parametric photoluminescence in spatially inhomogeneous systems is developed. The quantum Langevin equations are solved in a generalized Bogoliubov de Gennes approximation. We apply the formalism to the specific case of a disordered microcavity. In this case, we numerically solve the equations for the coherent emission and the p

Nicola Pizzolato, Davide Valenti, Dominique Persano Adorno, Bernardo Spagnolo

The evolutionary dynamics of a system of cancerous cells in a model of chronic myeloid leukemia (CML) is investigated by a statistical approach. Cancer progression is explored by applying a Monte Carlo method to simulate the stochastic behavior of cell reproduction and death in a population of blood cells which can experience genetic mutations. In CML front

Anton S. Galaev

Irreducible skew-Berger algebras $\g\subset\gl(n,\Co)$, i.e. algebras spanned by the images of the linear maps $R:\odot^2\Co^n\to\g$ satisfying the Bianchi identity, are classified. These Lie algebras can be interpreted as irreducible complex Berger superalgebras contained in $\gl(0|n,\Co)$.

Paolo Moretti, M. -Carmen Miguel

We discuss the role of dislocation assemblies such as grain boundaries in the dynamic response of a driven vortex lattice. We simulate the depinning of a field-cooled vortex polycrystal and observe a general enhancement of the critical current as well as a distinct crossover in the characterisitic of this quantity as a function of pinning density. The result

Roldao da Rocha, J. M. Hoff da Silva

In a previous paper we explicitly constructed a mapping that leads Dirac spinor fields to the dual-helicity eigenspinors of the charge conjugation operator (ELKO spinor fields). ELKO spinor fields are prime candidates for describing dark matter, and belong to a wider class of spinor fields, the so-called flagpole spinor fields, corresponding to the class-(5)

R. A. Jishi, H. M. Alyahyaei

We show that the strong hybridization between the iron 3d and the arsenic 4p orbitals, in the newly discovered iron-based high-T$_{c}$ superconductors, leads to an explanation of certain experimental observations that are presently not well understood. The existence of a lattice distortion, the smallness of the Fe magnetic moment in the undoped systems, and

Zhifan Chen, Alfred Z. Msezane

Photoionization of the I$^+$ ion in the energy range of the 4d giant resonance has been studied using our recently developed random-phase approximation with exchange (RPAE) method. Photoionization cross sections for the I$^+$ $4d-εf, εp$, $5s-εp$, $5p-εs ,εd$ have been obtained for each term of the ground state. Calculations include all the intra-shell and i

Guido Cognola, Sergio Zerbini

A brief introduction on the issue of stability in generalized modified gravity is presented and the dynamical system methods are used in the investigation of the stability of spatially flat homogeneous cosmologies within a large class of generalized modified gravity models in the presence of a relativistic matter-radiation fluid.

V. M. Braun, M. Göckeler, R. Horsley, T. Kaltenbrunner

Baryon distribution amplitudes (DAs) are crucial for the theory of hard exclusive reactions. We present a calculation of the first few moments of the leading-twist nucleon DA within lattice QCD. In addition we deal with the normalization of the next-to-leading (twist-four) DAs. The matrix elements determining the latter quantities are also responsible for pr

V. Mathieu, F. Buisseret, C. Semay, B. Silvestre-Brac

We present a model for odd-$C$ (negative charge parity) glueballs with three constituent gluons. The model is an extension of a previous study of two-gluon glueballs. We show that, even if spin-1 gluons seem to reproduce properly the lattice QCD spectrum for $C=+$ states, the extension for $C=-$ cannot match with the lattice results. Resorting to the helicit

Valentina Casarino, Paolo Ciatti

By using the notion of contraction of Lie groups, we transfer $L^p-L^2$ estimates for joint spectral projectors from the unit complex sphere $\sfera$ in ${\mathbb{C}}^{n+1}$ to the reduced Heisenberg group $h^{n}$. In particular, we deduce some estimates recently obtained by H. Koch and F. Ricci on $h^n$. As a consequence, we prove, in the spirit of Sogge&#3

Ph. Germain, S. Amokrane

The binodals and the non-ergodicity lines of a binary mixture of hard sphere-like particles with large size ratio are computed for studying the interplay between dynamic arrest and phase separation in depletion-driven colloidal mixtures. Contrarily to the case of hard core plus short range effective attraction, physical gellation without competition with the

S. M. Zebarjad, F. Falahati, H. Mehranfar

In this paper, we investigate the effects of the fourth generation of quarks on the double-lepton polarization asymmetries in the $B_s \rar ϕ\ell^+ \ell^-$ decay. It is shown that these asymmetries in $B_s \rar ϕ\ell^+ \ell^-$ decay compared with those of $B \rar K \ell^+ \ell^-$ decay are more sensitive to the fourth-generation parameters. We conclude that

L. Jin, B. Chen, Z. Song

Based on the exact results obtained by Bethe ansatz, we demonstrate the existence of stable bound pair (BP) wave packet in Bose Hubbard model with arbitrary on-site interaction U. In large-U regime, it is found that an incoming single-particle (SP) can coherently pass through a BP wave packet and leave a coherent shift in the position of it. This suggests a

Jernej Azarija, Daniel Král&#39;, Rok Erman, Matjaz Krnc

Let G be a plane graph with maximum face size D. If all faces of G with size four or more are vertex disjoint, then G has a cyclic coloring with D+1 colors, i.e., a coloring such that all vertices incident with the same face receive distinct colors.

Robert Droulans, Elisabeth Jourdain

We report on results of two years of INTEGRAL/SPI monitoring of the Galactic microquasar GRS 1915+105. From September 2004 to May 2006, the source has been observed twenty times with long (approx 100 ks) exposures. We present an analysis of the SPI data and focus on the description of the high-energy (> 20 keV) output of the source. We found that the 20 - 50

Daniel Král&#39;, Ladislav Stacho

We show that every plane graph with maximum face size four whose all faces of size four are vertex-disjoint is cyclically 5-colorable. This answers a question of Albertson whether graphs drawn in the plane with all crossings independent are 5-colorable.

Scipio Cuccagna

We consider examples of discrete nonlinear Schroedinger equations in Z admitting ground states which are orbitally but not asymptotically stable in l ^2(Z). The ground states contain internal modes which decouple from the continuous modes. The absence of leaking of energy from discrete to continues modes leads to an almost conservation and perpetual oscillat

A. Hübel, K. Held, J. Weis, K. v. Klitzing

A system consisting of two independently contacted quantum dots with strong electrostatic interaction shows interdot Coulomb blockade when the dots are weakly tunnel coupled to their leads. It is studied experimentally how the blockade can be overcome by correlated tunneling when tunnel coupling to the leads increases. The experimental results are compared w

Pulak Ranjan Giri

It is know that PT-symmetric models have real spectra provided the symmetry is not spontaneously broken. Even pseudo-hermitian models have real spectra, which enlarge the the class of non-hermitian models possessing real spectra. We however consider non-hermitian models in higher dimensions which are not necessarily explicit PT-symmetric nor pseudo-hermitian

Francisco M. Fernandez

We analyze a recent application of homotopy perturbation method to some heat-like and wave-like models and show that its main results are merely the Taylor expansions of exponential and hyperbolic functions. Besides, the authors require more boundary conditions than those already necessary for the solution of the problem by means of power series.

Johannes Vitalis Siven, Jeffrey Todd Lins, Anna Szymkowiak-Have

The value-at-risk of a delta-gamma approximated derivatives portfolio can be computed by numerical integration of the characteristic function. However, while the choice of parameters in any numerical integration scheme is paramount, in practice it often relies on ad hoc procedures of trial and error. For normal and multivariate $t$-distributed risk factors,

David A. Towers

A subalgebra B of a Lie algebra L is called a c-ideal of L if there is an ideal C of L such that L = B + C and B \cap C \leq B_L, where B_L is the largest ideal of $L$ contained in B. This is analogous to the concept of c-normal subgroup, which has been studied by a number of authors. We obtain some properties of c-ideals and use them to give some characteri

Nicolas Fournier

We consider a class of nonlinear partial-differential equations, including the spatially homogeneous Fokker-Planck-Landau equation for Maxwell (or pseudo-Maxwell) molecules. Continuing the work of Fontbona-Guérin-Méléard, we propose a probabilistic interpretation of such a P.D.E. in terms of a nonlinear stochastic differential equation driven by a standard B

J. Skowron, L. Wyrzykowski, S. Mao, M. Jaroszynski

Microlensing events are usually selected among single-peaked non-repeating light curves in order to avoid confusion with variable stars. However, a microlensing event may exhibit a second microlensing brightening episode when the source or/and the lens is a binary system. A careful analysis of these repeating events provides an independent way to study the s

H. Bravo-Alfaro, C. A. Caretta, C. Lobo, F. Durret

This series of papers explores the evolution of late-type galaxies in the rich cluster Abell 85. Here, we revisit the complex dynamical state of A 85 by using independent methods. We analyze the redshift distribution towards the cluster out to 40,000 km/s, and determine the mean redshifts of the background clusters A 87 and A 89. We then search for substruct

Petter Andreas Bergh

We study the vanishing of cohomology in triangulated categories admitting a central ring action. In particular, we study vanishing gaps and symmetry.

A. N. Ignatenko, V. Yu. Irkhin, A. A. Katanin

We consider a quantum two-dimensional O(N)xO(2)/O(N-2)xO(2) nonlinear sigma model for frustrated spin systems and formulate its 1/N-expansion which involves fluctuating scalar and vector fields describing kinematic and dynamic interactions, respectively. The ground state phase diagram of this model is obtained within the 1/N-expansion and 2+εrenormalization

B. Genolini, P. Barrillon, S. Blin, J. -E. Campagne

The next generation of proton decay and neutrino experiments, the post-SuperKamiokande detectors as those that will take place in megaton size water tanks, will require very large surfaces of photodetection and a large volume of data. Even with large hemispherical photomultiplier tubes, the expected number of channels should reach hundreds of thousands. A fu

M. J. Church, M. Balucinska-Church, N. K. Jackson, A. Gibiec

We present a new model for the Z-track phenomenon, based on analysis of the spectral evolution around the Z-track in several Z-track sources, in which radiation pressure plays a major role. Increasing mass accretion rate on the normal branch causes heating of the neutron star with the emissive flux from the surface increasing by an order of magnitude to beco

N. Marcelino, J. Cernicharo, B. Tercero, E. Roueff

We report on the first detection in space of fulminic acid, HCNO. This isomer of HNCO has been observed in three starless cores, B1, L1544 and L183, and in the low mass star forming region L1527 with a measured abundance ratio of HNCO/HCNO between 40-70. However, HCNO was not detected towards the direction of the cyanopolyyne peak of TMC-1 or towards the Ori

Morris L. Eaton, Robb J. Muirhead

This paper is motivated by the following observation. Take a 3 x 3 random (Haar distributed) orthogonal matrix $Γ$, and use it to &#34;rotate&#34; the north pole, $x_0$ say, on the unit sphere in $R^3$. This then gives a point $u=Γx_0$ that is uniformly distributed on the unit sphere. Now use the same orthogonal matrix to transform u, giving $v=Γu=Γ^2 x_0$.

Shamik Ghosh, Maitry Podder, Malay K. Sen

In this paper we obtain several characterizations of the adjacency matrix of a probe interval graph. In course of this study we describe an easy method of obtaining interval representation of an interval bipartite graph from its adjacency matrix. Finally, we note that if we add a loop at every probe vertex of a probe interval graph, then the Ferrers dimensio