December 2008 arXiv papers — page 32

Massimo Giovannini, Kerstin E. Kunze

Polarimetry of the Cosmic Microwave Background (CMB) represents one of the possible diagnostics aimed at testing large-scale magnetism at the epoch of the photon decoupling. The propagation of electromagnetic disturbances in a magnetized plasma leads naturally to a B-mode polarization whose angular power spectrum is hereby computed both analytically and nume

Jose Beltran Jimenez, Antonio L. Maroto

Dark energy is usually parametrized as a perfect fluid with negative pressure and a certain equation of state. Besides, it is supposed to interact very weakly with the rest of the components of the universe and, as a consequence, there is no reason to expect it to have the same large-scale rest frame as matter and radiation. Thus, apart from its equation of

Rudolph C. Hwa, C. B. Yang

Correlation between trigger and associated particles in jets produced on near and away sides of high-p_T triggers in heavy-ion collisions is studied. Hadronization of jets on both sides is treated by thermal-shower and shower-shower recombination. Energy loss of semihard and hard partons traversing the nuclear medium is parametrized in a way that renders goo

W. Polyzou, M. Tucker, S. Veerasamy, Ch. Elster

I summarize recent progress in the treatment of the Poincaré three-nucleon problem at intermediate energies

Antonio Dobado, Felipe J. Llanes-Estrada, Juan M. Torres-Rincon

The viscosity over entropy density ratio, or KSS number, can help isolate the critical point in the hadron phase-diagram in Relativistic Heavy Ion Collisions. We argue that this quantity does have a minimum at a phase transition or crossover. Although indications from conventional non-relativistic gases point out to even a divergence in eta/s when the phase-

D. Needell, J. A. Tropp, R. Vershynin

The two major approaches to sparse recovery are L1-minimization and greedy methods. Recently, Needell and Vershynin developed Regularized Orthogonal Matching Pursuit (ROMP) that has bridged the gap between these two approaches. ROMP is the first stable greedy algorithm providing uniform guarantees. Even more recently, Needell and Tropp developed the stable g

Peter Watson, Hugo Reinhardt

Two aspects of the color charge in Coulomb gauge continuum Yang-Mills theory are discussed. The first aspect is the existence of a conserved and vanishing total charge exhibited within the first order functional formalism. The second aspect is the closure of the set of Slavnov-Taylor identities in the second order functional formalism, such that the exact so

J. R. Martínez-Galarza, I. Kamp, K. Y. L. Su, A. Gáspár

We present a model that describes stellar infrared excesses due to heating of the interstellar (IS) dust by a hot star passing through a diffuse IS cloud. This model is applied to six lambda Bootis stars with infrared excesses. Plausible values for the IS medium (ISM) density and relative velocity between the cloud and the star yield fits to the excess emiss

K. Foyevtsova, Y. Zhang, H. O. Jeschke, R. Valenti

We investigate the microscopic model for the frustrated layered antiferromagnets Cs2CuCl4 and Cs2CuBr4 by performing ab initio density functional theory (DFT) calculations and with the help of the tight-binding method. The combination of both methods provide the relevant interaction paths in these materials, and we estimate the corresponding exchange constan

Rouzbeh Allahverdi, Bhaskar Dutta, Katherine Richardson-McDaniel, Yudi Santoso

We propose a simple model of supersymmetric dark matter that can explain recent results from PAMELA and ATIC experiments. It is based on a U(1)_B-L extension of the minimal supersymmetric standard model. The dark matter particle is a linear combination of the U(1)_B-L gaugino and Higgsino partners of Higgs fields that break the B-L around one TeV. The domina

Ilham Chakir, Maurice Pouzet

We study how the existence in an algebraic lattice $L$ of a chain of a given type is reflected in the join-semilattice $K(L)$ of its compact elements. We show that for every chain $α$ of size $κ$, there is a set $\B$ of at most $2^κ$ join-semilattices, each one having a least element such that an algebraic lattice $L$ contains no chain of order type $I(α)$ i

Hatem Mejjaoli

We introduce and study the Dunkl symmetric systems. We prove the well-posedness results for the Cauchy problem for these systems. Eventually we describe the finite speed of it. Next the semi-linear Dunkl-wave equations are also studied.

S. Dawson

In these lectures, I review the status of the electroweak sector of the Standard Model, with an emphasis on the importance of radiative corrections and searches for the Standard Model Higgs boson. A discussion of the special role of the TeV energy scale in electroweak physics is included.

K. A. Bugaev, V. K. Petrov, G. M. Zinovjev

The medium dependent finite width is introduced into an exactly solvable model with the general mass-volume spectrum of the QGP bags. The model allows us to estimate the minimal value of the QGP bags' width from the lattice QCD data. The large width of the QGP bags not only explains the observed deficit in the number of hadronic resonances comparing to t

Giacomo Nannicini, Pietro Belotti, Leo Liberti

Local branching is an improvement heuristic, developed within the context of branch-and-bound algorithms for MILPs, which has proved to be very effective in practice. For the binary case, it is based on defining a neighbourhood of the current incumbent solution by allowing only a few binary variables to flip their value, through the addition of a local branc

Martin Hennemann, Stephan M. Birkmann, Oliver Krause, Dietrich Lemke

The fate of massive cold clumps, their internal structure and collapse need to be characterised to understand the initial conditions for the formation of high-mass stars, stellar systems, and the origin of associations and clusters. We explore the onset of star formation in the 75 M_sun SMM1 clump in the region ISOSS J18364-0221 using infrared and (sub-)mill

C. Y. Hui, W. Becker

We have studied the supernova remnant G67.7+1.8 with the Chandra X-ray observatory. The remnant's X-ray morphology correlates well with the double-arc structure seen at radio wavelength. The X-ray spectra of the northern and southern rim of G67.7+1.8 exhibit emission line features of highly ionized metals, which suggests that most of the observed X-rays

E. Oliva

This paper reviews the scientific use of the TNG from the beginning of regular observations till the end of 2007. Statistics are given for the time request, use and productivity of the telescope and its focal plane instruments. Information on the down-times and a list of the major technical works/upgrades are also included.

Stefan Pinkert, Joerg Schultz, Joerg Reichardt

Cellular function is widely believed to be organized in a modular fashion. On all scales and at all levels of complexity, relatively independent sub-units perform relatively independent sub-tasks of biological function. This functional modularity must be reflected in the topology of molecular networks. But how a functional module should be represented in an

Denis Parganlija, Francesco Giacosa, Dirk H. Rischke

We calculate low-energy meson decay processes and pion-pion scattering lengths in a two-flavour linear sigma model with global chiral symmetry, exploring the scenario in which the scalar mesons $f_0$(600) and $a_0$(980) are assumed to be $\bar q q$ states.

A. S. Volokitin, B. Atamaniuk

In the study on nonlinear wave-wave processes in an ionosphere and a magnetosphere usually the main attention is paid to investigation of plasma turbulence at well developed stage, when the wide spectrum of plasma wave is present. On the other side, it is well known that even if the number of cooperating waves remains small due to a competition of processes

H. Korhonen, D. Elstner

Differential rotation plays a crucial role in the alpha-omega dynamo, and thus also in creation of magnetic fields in stars with convective outer envelopes. Still, measuring the radial differential rotation on stars is impossible with the current techniques, and even the measurement of surface differential rotation is difficult. In this work we investigate t

Mykhaylo Tyomkyn

We construct a tree T of maximal degree 3 with infinitely many leaves such that whenever finitely many of them are removed, the remaining tree is isomorphic to T. In this sense T resembles an infinite star.

Qing Yang, Ming Yang, Da-Chuang Li, Zhuo-Liang Cao

Two noninteracting atoms, initially entangled in Bell states, are coupled to a one-mode cavity. Based on the reduced non-perturbative quantum master equation, the entanglement evolution of the two atoms with decay is investigated beyond rotating-wave approximation. It is shown that the counter-rotating wave terms have great influence on the disentanglement b

R. Schicker

The ALICE experiment at the LHC is presented and a diffractive double gap trigger is described. Signatures of Pomeron and Odderon are discussed together with photoproduction of heavy quarks as a possible signature of gluon saturation.

R. Machado, M. Sepliarsky, M. G. Stachiotti

The phase transition sequence of SrBi$_2$Ta$_2$O$_9$ is investigated using a shell model with parameters fitted to first-principles calculations. We show that the complex interplay between polar and nonpolar instabilities leads to the presence of two phase transitions, corroborating the existence of an intermediate orthorhombic paraelectric phase. This phase

L. Wardil, J. K. L. da Silva

We study the robustness and stability of the yeast cell regulatory network by using a general inhomogeneous discrete model. We find that inhomogeneity, on average, enhances the stability of the biggest attractor of the dynamics and that the large size of the basin of attraction is robust against changes in the parameters of inhomogeneity. We find that the mo

G. Japaridze

In this pedagogical note it is demonstrated how the numeric value of fine structure constant may be established by comparing results following from the calculations in the framework of Quantum Electrodynamics with the experimental data. As an observable, the coefficient of 1/r in the Coulomb law is used.

Michel Planat, Milan Minarovjech, Metod Saniga

Ramanujan sums are exponential sums with exponent defined over the irreducible fractions. Until now, they have been used to provide converging expansions to some arithmetical functions appearing in the context of number theory. In this paper, we provide an application of Ramanujan sum expansions to periodic, quasiperiodic and complex time series, as a vital

Nikolaos Berketis, Christodoulos Athanasiadis

We study the direct and inverse scattering problems when the incident electromagnetic field is a time harmonic point- generated wave in a chiral medium and the scatterer is a perfectly conducting sphere. The exact Green s function and the electric far-field patterns of the scattering problem are constructed. For a small sphere, a closed-form approximation of

Jinshan Zhang

These notes are dedicated to whom may be interested in algorithms, Markov chain, coupling, and graph theory etc. I present some preliminaries on coupling and explanations of the important formulas or phrases, which may be helpful for us to understand D. Weitz's paper "Combinatorial Criteria for Uniqueness of Gibbs Measures" with ease.

Oz Ben-Shimol

Let $p$ be an odd prime. Let $F/k$ be a cyclic extension of degree $p$ and of characteristic different from $p$. The explicit constructions of the non-abelian $p^{3}$-extensions over $k$, are induced by certain elements in ${F(μ_{p})}^{*}$. In this paper we let $k=\QQ$ and present sufficient conditions for these elements to be suitable for the constructions.

Rolando Magnanini, Shigeru Sakaguchi

We consider an entire graph S of a continuous real function over (N-1)-dimensional Euclidean space with N larger than or equal to 3. Let D be a domain in N-dimensional Euclidean space with S as a boundary. Consider in D the heat flow with initial temperature 0 and boundary temperature 1. The problem we consider is to characterize S in such a way that there e

Florin Pop

This paper presents a scheduling framework that is configured for, and used in physic systems. Our work addresses the problem of scheduling various computationally intensive and data intensive applications that are required for extracting information from satellite images. The proposed solution allows mapping of image processing applications onto available r

Jocelyn S. Read, Benjamin D. Lackey, Benjamin J. Owen, John L. Friedman

We introduce a parameterized high-density equation of state (EOS) in order to systematize the study of constraints placed by astrophysical observations on the nature of neutron-star matter. To obtain useful constraints, the number of parameters should be smaller than the number of neutron-star properties that have been measured or will have been measured in

Wei Zhou, Lin He, Rongming Wang, Kun Zheng

One-dimensional Ni/Ni3C core-shell nanoball chains with an average diameter by around 30 nm were synthesized by means of a mild chemical solution method using a soft template of trioctylphosphineoxide (TOPO). It was revealed that the uniform Ni nanochains were capped with Ni3C thin shells by about 1 to 4 nm in thickness and each Ni core consists of polygrain

Michał Hanasz, Kacper Kowalik, Dominik Wóltański, Rafał Pawłaszek

We present a new multi-fluid, grid MHD code PIERNIK, which is based on the Relaxing TVD scheme. The original scheme has been extended by an addition of dynamically independent, but interacting fluids: dust and a diffusive cosmic ray gas, described within the fluid approximation, with an option to add other fluids in an easy way. The code has been equipped wi

V. Shikin, E. Klinovya

Discussed in the paper is a mixed scenario of the charged liquid surface reconstruction in the situation where the 2D surface charge density is close to its saturation value.

L. M. Camacho, J. R. Gomez, B. A. Omirov, A. Kh. Khudoyberdiyev

We present the description up to isomorphism of Leibniz superalgebras with characteristic sequence $(n|m_1,...,m_k)$ and nilindex $n+m,$ where $m=m_1+ >...+m_k,$ $n$ and $m$ ($m\neq 0$) are dimensions of even and odd parts, respectively.

Vitalij M. Bondarenko, Tatiana G. Gerasimova, Vladimir V. Sergeichuk

Pairs (A,B) of mutually annihilating operators AB=BA=0 on a finite dimensional vector space over an algebraically closed field were classified by Gelfand and Ponomarev [Russian Math. Surveys 23 (1968) 1-58] by method of linear relations. The classification of (A,B) over any field was derived by Nazarova, Roiter, Sergeichuk, and Bondarenko [J. Soviet Math. 3

Mathieu Lewin, Eric Séré

This paper, devoted to the study of spectral pollution, contains both abstract results and applications to some self-adjoint operators with a gap in their essential spectrum occuring in Quantum Mechanics. First we consider Galerkin basis which respect the decomposition of the ambient Hilbert space into a direct sum $H=PH\oplus(1-P)H$, given by a fixed orthog

Joachim Stubbe, Marc Vuffray

We prove the existence of quasi-stationary symmetric solutions with exactly n>=0 zeros and uniqueness for n=0 for the Schrödinger-Newton model in one dimension and in two dimensions along with an angular momentum m>=0. Our result is based on an analysis of the corresponding system of second-order differential equations.

Katarzyna Otmianowska-Mazur, Marian Soida, Barbara Kulesza-Żydzik, Michał Hanasz

In the present paper we construct maps of polarized synchrotron radio emission of a whole galaxy, based on local models of the cosmic ray (CR) driven dynamo. We perform numerical simulations of the dynamo in local Cartesian domains, with shear-periodic boundary conditions, placed at the different galactocentric radii. Those local solutions are concatenated t

W. A. Dziembowski

After a historical introduction, I present the current status of our understanding of the mechanism responsible for pulsation in Beta Cephei and SPB stars.

Javier Villarroel, Miquel Montero

The usual development of the continuous-time random walk (CTRW) proceeds by assuming that the present is one of the jumping times. Under this restrictive assumption integral equations for the propagator and mean escape times have been derived. We generalize these results to the case when the present is an arbitrary time by recourse to renewal theory. The cas

S. Wende, A. Reiners, H. G. Ludwig

We present synthetic FeH band spectra in the z-filter range for several M-dwarf models with logg=3.0-5.0 [cgs] and Teff=2800K -3450K. Our aim is to characterize convective velocities in M-dwarfs and to give a rough estimate of the range in which 3D-atmosphere treatment is necessary and where 1D-atmosphere models suffice for the interpretation of molecular sp

Franck Sueur

We deal with the incompressible Navier-Stokes equations, in two and three dimensions, when some vortex patches are prescribed as initial data i.e. when there is an internal boundary across which the vorticity is discontinuous. We show -thanks to an asymptotic expansion- that there is a sharp but smooth variation of the fluid vorticity into a internal layer m

Claude Fabre, J. -B. Fouet, Agnès Maître

We consider the problem of the measurement of very small displacements in the transverse plane of an optical image with a split photodetector. We show that the standard quantum limit for such a measurement, which is equal to the diffraction limit divided by the square root of the number of photons used in the measurement, cannot be overcome by use of ordinar

Serge F. Timashev, Yuriy S. Polyakov

The problem of information extraction from discrete stochastic time series, produced with some finite sampling frequency, using flicker-noise spectroscopy, a general framework for information extraction based on the analysis of the correlation links between signal irregularities and formulated for continuous signals, is discussed. It is shown that the mathem

E. P. Shabalin

Contrary to wide-spread opinion that the final state interaction (FSI) enhances the amplitude $<2π;I=0|K^0>$, we argue that FSI does not increase the absolute value of this amplitude.

A. Derekas, L. L. Kiss, T. R. Bedding, M. C. B. Ashley

We have carried out a photometric and spectroscopic survey of bright high-amplitude delta Scuti (HADS) stars. The aim was to detect binarity and multiperiodicity (or both) in order to explore the possibility of combining binary star astrophysics with stellar oscillations. Here we present the first results for ten, predominantly southern, HADS variables. We d

S. Capozziello, P. Martin-Moruno, C. Rubano

We present an $f(R)$-cosmological model with an exact analytic solution, coming from the request of the existence of a Noether symmetry, which is able to describe a dust-dominated decelerated phase before the current accelerated phase of the universe.

Piotr Berman, Marek Karpinski, Alex Zelikovsky

We design a 3/2 approximation algorithm for the Generalized Steiner Tree problem (GST) in metrics with distances 1 and 2. This is the first polynomial time approximation algorithm for a wide class of non-geometric metric GST instances with approximation factor below 2.

F. A. Rajgara, D. Mathur, A. K. Dharmadhikari, C. P. Safvan

H-atoms in H$_2$O are rearranged by strong optical fields generated by intense, 10 fs laser pulses to form H$_2^+$, against prevailing wisdom that strong fields inevitably lead to multiple molecular ionization and the subsequent Coulomb explosion into fragments. This atomic rearrangement is shown to occur within a single 10 fs pulse. Comparison with results

Th. Diakonidis, J. Fleischer, J. Gluza, K. Kajda

We perform a complete analytical reduction of general one-loop Feynman integrals with five and six external legs for tensors up to rank R=3 and 4, respectively. An elegant formalism with extensive use of signed minors is developed for the cancellation of inverse Gram determinants. The 6-point tensor functions of rank R are expressed in terms of 5-point tenso

M. Blasone, A. Capolupo, C. R. Ji, G. Vitiello

We discuss flavor charges and states for interacting mixed neutrinos in QFT. We show that the Pontecorvo states are not eigenstates of the flavor charges. This implies that their use in describing the flavor neutrinos produces a violation of lepton charge conservation in the production/detection vertices. The flavor states defined as eigenstates of the flavo

Chris Peters, Morihiko Saito

Let $X$ be an irreducible complex analytic space with $j:U\into X$ an immersion of a smooth Zariski open subset, and let $\bV$ be a variation of Hodge structure of weight $n$ over $U$. Assume $X$ is compact Kähler. Then provided the local monodromy operators at infinity are quasi-unipotent, $IH^k(X, \bV)$ is known to carry a pure Hodge structure of weight $k

L. Vidmar, J. Bonca, S. Maekawa

Using recently developed numerical method we compute charge stiffness and optical conductivity of the t-J model coupled to optical phonons. Coherent hole motion is most strongly influenced by the electron-phonon coupling within the physically relevant regime of the exchange interaction. We find unusual non-monotonous dependence of the charge stiffness as a f

S. I. Doronin, E. B. Fel&#39;dman, M. M. Kucherov, A. N. Pyrkov

We consider the adiabatic demagnetization in the rotating reference frame (ADRF) of a system of dipolar coupled nuclear spins $s=1/2$ in the external magnetic field. The demagnetization starts with the offset of the external magnetic field (in frequency units) from the Larmor frequency being several times greater than the local dipolar field. For different s

A. E. Petrova, S. M. Stishov

Measurements of the sound velocities in a single crystal of MnSi were performed in the temperature range 4-150 K. Elastic constants, controlling propagation of longitudinal waves reveal significant softening at a temperature of about 29.6 K and small discontinuities at $\sim$28.8 K, which corresponds to the magnetic phase transition in MnSi. In contrast the

Vladislav V. Goldberg, Valentin V. Lychagin

In the present paper we study geometric structures associated with webs of hypersurfaces. We prove that with any geodesic (n+2)-web on an n-dimensional manifold there is naturally associated a unique projective structure and, provided that one of web foliations is pointed, there is also associated a unique affine structure. The projective structure can be ch

Mikhail Ilyin, Petr Kulish, Vladimir Lyakhovsky

It is demonstrated that decompositions of integrable highest weight modules of a simple Lie algebra with respect to its reductive subalgebra obey the set of algebraic relations leading to the recursive properties for the corresponding branching coefficients. These properties are encoded in the special element (of the formal algebra E(g)) Gamma_(a ->g) that d

P. K. Lightfoot, G. J. Barker, K. Mavrokoridis, Y. A. Ramachers

For the first time secondary scintillation, generated within the holes of a thick gas electron multiplier (TGEM) immersed in liquid argon, has been observed and measured using a silicon photomultiplier device (SiPM). 250 electron-ion pairs, generated in liquid argon via the interaction of a 5.9KeV Fe-55 gamma source, were drifted under the influence of a 2.5

Nicolas Ressayre

Consider a partial flag variety $X$ which is not a grassmaninan. Consider also its cohomology ring ${\rm H}^*(X,\ZZ)$ endowed with the base formed by the Poincaré dual classes of the Schubert varieties. In \cite{Richmond:recursion}, E. Richmond showed that some coefficient structure of the product in ${\rm H}^*(X,\ZZ)$ are products of two such coefficients f

Rolf Kappl, Hans Peter Nilles, Saul Ramos-Sanchez, Michael Ratz

We show that hierarchically small vacuum expectation values of the superpotential in supersymmetric theories can be a consequence of an approximate R symmetry. We briefly discuss the role of such small constants in moduli stabilization and understanding the huge hierarchy between the Planck and electroweak scales.

Sangwoong Park, Bongsoo Kim, Sung Jong Lee

We find a breakdown of the critical dynamic scaling in the coarsening dynamics of an antiferromagnetic {\em XY} model on the kagome lattice when the system is quenched from disordered states into the Kosterlitz-Thouless ({\em KT}) phases at low temperatures. There exist multiple growing length scales: the length scales of the average separation between fract

A. Ciattoni, A. Marini, C. Rizza, E. DelRe

We theoretically investigate collision of optical beams travelling in opposite directions through a centrosymmetric photorefractive crystal biased by a spatially non-uniform voltage. We analytically predict the fusion of counterpropagating solitons in conditions in which the applied voltage is rapidly modulated along the propagation axis, so that self-bendin

M C Gallardo, J M Martin-Olalla, F J Romero, J del Cerro

The influence of a transverse electric field in the specific heat of triglycine sulphate (TGS) has been studied. The specific heat of TGS has been measured heating the sample from ferroelectric to paraelectric phase after prolonged transverse electric field (i.e. perpendicular to the ferroelectric axis). It is shown that the specific heat of TGS can remember

Gabrio Caimi, Holger Flier, Martin Fuchsberger, Marc Nunkesser

In this paper a greedy algorithm to detect conflict cliques in interval graphs and circular-arc graphs is analyzed. In a graph, a stable set requires that at most one vertex is chosen for each edge. It is equivalent to requiring that at most one vertex for each maximal clique is chosen. We show that this algorithm finds all maximal cliques for interval graph

Yan Chen, Bo-Qiang Ma

We introduce a classification number $n$ which describes the baryon mass information in a fuzzy manner. According to $n$ and $J^p$ of baryons, we put all known light baryons in a simple table in which some baryons with same ($n$, $J^p$) are classified as members of known octets or decuplets. Meanwhile, we predict two new possible octets.

Elias Baro, Margarita Otero

In &#34;On o-minimal homotopy groups&#34;, o-minimal homotopy was developed for the definable category, proving o-minimal versions of the Hurewicz theorems and the Whitehead theorem. Here, we extend these results to the category of locally definable spaces, for which we introduce homology and homotopy functors. We also study the concept of connectedness in V

Benoit Kloeckner

The Chabauty space of a topological group is the set of its closed subgroups, endowed with a natural topology. As soon as $n>2$, the Chabauty space of $R^n$ has a rather intricate topology and is not a manifold. By an investigation of its local structure, we fit it into a wider, but too wild, class of topological spaces (namely Goresky-MacPherson stratified

Arsen Khvedelidze

The semiclassical dynamics of a charged spin-1/2 particle in an intense electromagnetic plane wave is analyzed beyond the electric dipole approximation and taking into account the leading relativistic corrections to the Pauli equation. It is argued that the adiabatic spin evolution driven by a low intensity radiation changes its character drastically as an i

Kosuke Nagashio, Tomonori Nishimura, Koji Kita, Akira Toriumi

The electric properties of mono- and multi-layer graphene films were systematically studied with the layer number determined by their optical contrast. The current modulation increased monotonically with a decrease in the layer number due to the reduction of the interlayer scattering. Carrier mobility in the monolayer was significantly greater than that in t

Katsuaki Asano, Fumio Takahara

Through detailed numerical simulations, we demonstrate that relativistic outflows (Lorentz factor $Γ\sim 7$) of electron-positron pairs can be produced by radiative acceleration even when the flow starts from a nearly pair equilibrium state at subrelativistic temperatures. Contrary to the expectation that pairs annihilate during an expansion stage for such l

Michele Cantiello, Gabriella Raimondo, Enzo Brocato, Ilaria Biscardi

We present some results on the study of stellar population properties and distances of galaxies using the SBF technique. The applications summarized here show that the Surface Brightness Fluctuations (SBF) method is able to i) provide accurate distances of resolved and unresolved stellar systems from ~10 Kpc to ~150 Mpc, and ii) to reliably constrain the phy

Jerome Droniou, Robert Eymard, Thierry Gallouët, Raphaele Herbin

We investigate the connections between several recent methods for the discretization of anisotropic heterogeneous diffusion operators on general grids. We prove that the Mimetic Finite Difference scheme, the Hybrid Finite Volume scheme and the Mixed Finite Volume scheme are in fact identical up to some slight generalizations. As a consequence, some of the ma

Alessandro Ruzzi

In a previous paper we have classified the smooth projective symmetric G-varieties with Picard number one (and G semisimple). In this work we give a geometrical description of such varieties. In particular, we determine their group of automorphisms. When this group, Aut(X), acts non-transitively on X, we describe a G-equivariant embedding of the variety X in

ANTARES collaboration, M. Ageron

In this paper we report on the data recorded with the first Antares detector line. The line was deployed on the 14th of February 2006 and was connected to the readout two weeks later. Environmental data for one and a half years of running are shown. Measurements of atmospheric muons from data taken from selected runs during the first six months of operation

Mikaël Ates, Christophe Gravier, Jérémy Lardon, Jacques Fayolle

Digital identity management intra and inter information systems, and, service oriented architectures, are the roots of identity federation. This kind of security architectures aims at enabling information system interoperability. Existing architectures, however, do not consider interoperability of heterogeneous federation architectures, which rely on differe

Ioannis Emmanouil, Roman Mikhailov

In this paper, we consider for any free presentation $G = F/R$ of a group $G$ the coinvariance $H_{0}(G,R_{ab}^{\otimes n})$ of the $n$-th tensor power of the relation module $R_{ab}$ and show that the homology group $H_{2n}(G,{\mathbb Z})$ may be identified with the limit of the groups $H_{0}(G,R_{ab}^{\otimes n})$, where the limit is taken over the categor

Jun Sung Kim, Seunghyun Khim, Liqin Yan, N. Manivannan

In order to investigate whether magnetism and superconductivity coexist in Co-doped SrFe$_2$As$_2$, we have prepared single crystals of SrFe$_{2-x}$Co$_x$As$_2$, $x$ = 0 and 0.4, and characterized them via X-ray diffraction, electrical resistivity in zero and applied field up to 9 T as well as at ambient and applied pressure up to 1.6 GPa, and magnetic susce

Ching-Ming Chen, Tianjun Li, Dimitri V. Nanopoulos

We show that there exist supersymmetric Minkowski vacua on Type IIB toroidal orientifold with general flux compactifications where the RR tadpole cancellation conditions can be relaxed and the Freed-Witten anomaly can be cancelled elegantly. We present a realistic Pati-Salam like flux model without the Freed-Witten anomaly. At the string scale, we can break

Rowan Killip, Monica Visan

We consider two classes of defocusing energy-supercritical nonlinear Schrödinger equations in dimensions $d\geq 5$. We prove that if the solution $u$ is apriorily bounded in the critical Sobolev space, that is, $u\in L_t^\infty \dot H^{s_c}_x$, then $u$ is global and scatters.

M. S. Majdoub, R. Maranganti, P. Sharma

Thin films of high-permittivity dielectrics are considered ideal candidates for realizing high charge density nanosized capacitors for use in next generation energy storage and nanoelectronic applications. The experimentally observed capacitance of such film nanocapacitors is, however, an order of magnitude lower than expected. This dramatic drop in capacita

Mohammud Foondun

We consider the operator $\sL$ defined on $C^2(\bR^d)$ functions by \sL f(x)&=&{1/2}\sum_{i,j=1}^d a_{ij}(x)\frac{\partial^2f(x)}{\partial x_i\partial x_j}+\sum_{i=1}^d b_i(x)\frac{\partial f(x)}{\partial x_i} &+&\int_{\bR^d\backslash\{0\}}[f(x+h)-f(x)-1_{(|h|\leq1)}h\cdot \grad f(x)]n(x,h)dh. Under the assumption that the local part of the operator is unifo

Kh. M. Shadimetov, A. R. Hayotov, F. A. Nuraliev

In this paper in the space $L_2^{(m)}(0,1)$ the problem of construction of optimal quadrature formulas is considered. Here the quadrature sum consists on values of integrand at nodes and values of first derivative of integrand at the end points of integration interval. The optimal coefficients are found and norm of the error functional is calculated for arbi

Chinping Chen, Lin He, Lin Lai, Hua Zhang

Fine powders of micron- and submicron-sized particles of undoped Cu2O semiconductor, with three different sizes and morphologies have been synthesized by different chemical processes. These samples include nanospheres 200 nm in diameter, octahedra of size 1 micron, and polyhedra of size 800 nm. They exhibit a wide spectrum of magnetic properties. At low temp

Y. Xia, L. Wray, D. Qian, D. Hsieh

The interface between a superconductor and a topological insulator has been proposed to harbor novel quasiparticles that realize physical schemes for fault-tolerant quantum computation. Here, we present high resolution angle-resolved photoemission experimental results, which along with first principles calculations, suggest that the surface-edge states of Bi

R. N. Lee, A. I. Milstein

The quasiclassical correction to the Moliere&#39;s formula for multiple scattering is derived. The consideration is based on the scattering amplitude, obtained with the first quasiclassical correction taken into account for arbitrary localized but not spherically symmetric potential. Unlike the leading term, the correction to the Moliere&#39;s formula contai

Antonio H. Castro Neto, Valeri N. Kotov, Johan Nilsson, Vitor M. Pereira

We review the problem of adatoms in graphene under two complementary points of view, scattering theory and strong correlations. We show that in both cases impurity atoms on the graphene surface present effects that are absent in the physics of impurities in ordinary metals. We discuss how to observe these unusual effects with standard experimental probes suc

Guangcheng Xiong, Yuansha Chen, Liping Chen, Guijun Lian

Charge carrier injection performed in Pr0.7Ca0.3MnO3 (PCMO) hetero-structure junctions exhibits stable without electric fields and dramatic changes in both resistances and interface barriers, which are entirely different from behaviors of semiconductor devices. Disappearance and reversion of interface barriers suggest that the adjustable resistance switching

Natarajan Sathiyamoorthy Venkataramanan, Mohammad Khazaei, Ryoji Sahara, Hiroshi Mizuseki

Absorption of hydrogen molecules on Nickel and Rhodium doped hexagonal boron nitride(BN) sheet is investigated by using the first principle method. The most stable site for the Ni atom was the on top side of nitrogen atom, while Rh atoms deservers a hollow site over the hexagonal BN sheet. The first hydrogen molecule was absorbed dissociatively over Rh atom,

Chao-Jun Feng

In this letter, we regard the $f(R)$ theory as an effective description for the acceleration of the universe and reconstruct the function $f(R)$ from the Ricci dark energy, which respects holographic principle of quantum gravity. By using different parameter $α$ in RDE, we show the behaviors of reconstructed $f(R)$ and find they are much different in the fut

Katrien Kolenberg, Elisabeth Guggenberger, Thebe Medupe, Patrick Lenz

We present our analysis of photometric data in the Johnson B and V filter of the southern Blazhko star SS For. In parallel, we analyzed the V observations obtained with the ASAS-3 photometry of the star gathered between 2000 and 2008. In the frequency spectra resulting from a Fourier analysis of our data, the triplet structure is detectable up to high order,

Ayumi Asai, Kazunari Shibata, Takako T. Ishii, Mitsuo Oka

We present a detailed examination of the features of the Active Region (AR) NOAA 10798. This AR generated coronal mass ejections (CMEs) that caused a large geomagnetic storm on 24 August 2005 with the minimum Dst index of -216 nT. We examined the evolution of the AR and the features on/near the solar surface and in the interplanetary space. The AR emerged in

L. Wray, D. Qian, D. Hsieh, Y. Xia

We present a systematic angle-resolved photoemission spectroscopic study of the high-Tc superconductor class (Sr/Ba){1-x}(K/Na)xFe2As2. By utilizing a photon-energy-modulation contrast and scattering geometry we report the Fermi surface and the momentum dependence of the superconducting gap, Delta(k). A prominent quasiparticle dispersion kink reflecting stro

Amanda I. Karakas, Hye Young Lee, Maria Lugaro, J. Goerres

The recent experimental evaluation of the 18F(a,p)21Ne reaction rate, when considering its associated uncertainties, presented significant differences compared to the theoretical Hauser-Feshbach rate. This was most apparent at the low temperatures relevant for He-shell burning in asymptotic giant branch (AGB) stars. Investigations into the effect on AGB nucl

Stefan Klumpp, Terence Hwa

Physiological changes which result in changes in bacterial gene expression are often accompanied by changes in the growth rate for fast adapting enteric bacteria. Since the availability of RNA polymerase (RNAP) in cells is dependent on the growth rate, transcriptional control involves not only the regulation of promoters, but also depends on the available (o

A. Savin, B. Sternin

Elliptic operators on stratified manifolds with any finite number of strata are considered. Under certain assumptions on the symbols of operators, we obtain index formulas, which express index as a sum of indices of elliptic operators on the strata.