December 2008 arXiv papers — page 30

N. Andersson, K. Glampedakis, L. Samuelsson

We investigate the role of neutron star superfluidity for magnetar oscillations. Using a plane-wave analysis we estimate the effects of a neutron superfluid in the elastic crust region. We demonstrate that the superfluid imprint is likely to be more significant than the effects of the crustal magnetic field. We also consider the region immediately beneath th

ZEUS Collaboration

The semi-inclusive reaction e+ p -> e+ X p was studied with the ZEUS detector at HERA using an integrated luminosity of 12.8 pb-1. The final-state proton, which was detected with the ZEUS leading proton spectrometer, carried a large fraction of the incoming proton energy, xL>0.32, and its transverse momentum squared satisfied pT^2<0.5 GeV^2; the exchanged ph

Jeremy Shears, Ian Miller, Steve Brady

Our observations of the first reported outburst of SDSS J081321.91+452809.4 during 2008 April show that this cataclysmic variable is a dwarf nova. The outburst amplitude was at least 3.1 magnitudes and the outburst appears to have been rather short-lived at around 3 days with a rapid decline to quiescence of 0.73 mag/day.

Mohammad Nazari, Abolghasem Sayadiyan, SeyedMajid Valiollahzadeh

In this paper, we discuss the issues in automatic recognition of vowels in Persian language. The present work focuses on new statistical method of recognition of vowels as a basic unit of syllables. First we describe a vowel detection system then briefly discuss how the detected vowels can feed to recognition unit. According to pattern recognition, Support V

P. J. Rippon, G. M. Stallard

We show that for any transcendental meromorphic function $f$ there is a point $z$ in the Julia set of $f$ such that the iterates $f^n(z)$ escape, that is, tend to $\infty$, arbitrarily slowly. The proof uses new covering results for analytic functions. We also introduce several slow escaping sets, in each of which $f^n(z)$ tends to $\infty$ at a bounded rate

Ashraf Hossain, S. Chakrabarti, P. K. Biswas

Network coverage of wireless sensor network (WSN) means how well an area of interest is being monitored by the deployed network. It depends mainly on sensing model of nodes. In this paper, we present three types of sensing models viz. Boolean sensing model, shadow-fading sensing model and Elfes sensing model. We investigate the impact of sensing models on ne

Carsten Marr, Marc-Thorsten Huett

We present an intuitive formalism for implementing cellular automata on arbitrary topologies. By that means, we identify a symmetry operation in the class of elementary cellular automata. Moreover, we determine the subset of topologically sensitive elementary cellular automata and find that the overall number of complex patterns decreases under increasing ne

SeyyedMajid Valiollahzadeh, Mohammad Nazari, Massoud Babaie-Zadeh, Christian Jutten

Recently, great attention was intended toward overcomplete dictionaries and the sparse representations they can provide. In a wide variety of signal processing problems, sparsity serves a crucial property leading to high performance. Inpainting, the process of reconstructing lost or deteriorated parts of images or videos, is an interesting application which

Oliver Bar, Silvia Necco, Stefan Schaefer

We study the impact of explicit chiral symmetry breaking of Wilson fermions on mesonic correlators in the epsilon-regime using Wilson chiral perturbation theory (WChPT). We generalize the epsilon-expansion of continuum ChPT to nonzero lattice spacings for various quark mass regimes. It turns out that the corrections due to a nonzero lattice spacing are highl

P. L. Garrido, G. Gallavotti

Revisiting canonical integration of the classical pendulum around its unstable equilibrium, normal hyperbolic canonical coordinates are constructed

D. Dudal, S. P. Sorella, N. Vandersickel, H. Verschelde

This paper presents a complete algebraic proof of the renormalizability of the gauge invariant $d=4$ operator $F_{μν}^2(x)$ to all orders of perturbation theory in pure Yang-Mills gauge theory, whereby working in the Landau gauge. This renormalization is far from being trivial as mixing occurs with other $d=4$ gauge variant operators, which we identify expli

Nicolas Combe, Jean Roch Huntzinger, Joseph Morillo

We theoretically study the propagation of sound waves in GaAs/AlAs superlattices focussing on periodic modes in the vicinity of the band gaps. Based on analytical and numerical calculations, we show that these modes are the product of a quickly oscillating function times a slowly varying envelope function. We carefully study the phase of the envelope functio

Maarten Reyniers, Pieter Degroote, Dennis Bodewits, Jan Cuypers

Aims. Rotation periods of cometary nuclei are scarce, though important when studying the nature and origin of these objects. Our aim is to derive a rotation period for the nucleus of comet C/2004 Q2 (Machholz). Methods. C/2004 Q2 (Machholz) was monitored using the Merope CCD camera on the Mercator telescope at La Palma, Spain, in January 2005, during its clo

Beatriz Errea, Jorge Dukelsky, Gerardo Ortiz

We introduce an exactly solvable model for trapped three-color atom gases. Applications to a cigar-shaped trapped cold fermions reveal a complex structure of breached pairing phases. We find two competing superfluid phases at weak and intermediate couplings, each one with two color pair condensates, that can be distinguished from density profile measurements

E. Goldobin, K. Vogel, W. P. Schleich, D. Koelle

We consider a symmetric 0-pi Josephson junction of length $L$, which classically can be in one of two degenerate ground states up or down, corresponding to supercurrents circulating clockwise or counterclockwise around the 0-pi boundary. When the length $L$ of the junction becomes smaller than the Josephson penetration depth $\lambda_J$, the system can switc

Julian P. Velev, Chun-Gang Duan, J. D. Burton, Alexander Smogunov

Magnetic tunnel junctions (MTJs), composed of two ferromagnetic electrodes separated by a thin insulating barrier layer, are currently used in spintronic devices, such as magnetic sensors and magnetic random access memories. Recently, driven by demonstrations of ferroelectricity at the nanoscale, thin-film ferroelectric barriers were proposed to extend the f

Thomas Schwetz

The potential of future high statistics atmospheric neutrino experiments is considered, having in mind currently discussed huge detectors of various technologies (water Cerekov, magnetized iron, liquid Argon). I focus on the possibility to use atmospheric data to determine the octant of $θ_{23}$ and the neutrino mass hierarchy. The sensitivity to the $θ_{23}

R M L Evans, Manlio Tassieri, Dietmar Auhl, Thomas A Waigh

We remove the need for Laplace/inverse-Laplace transformations of experimental data, by presenting a direct and straightforward mathematical procedure for obtaining frequency-dependent storage and loss moduli ($G&#39;(ω)$ and $G&#34;(ω)$ respectively), from time-dependent experimental measurements. The procedure is applicable to ordinary rheological creep (s

Luigi Santocanale, Yde Venema

This paper exhibits a general and uniform method to prove completeness for certain modal fixpoint logics. Given a set Γof modal formulas of the form γ(x, p1, . . ., pn), where x occurs only positively in γ, the language L\sharp (Γ) is obtained by adding to the language of polymodal logic a connective \sharp\_γfor each γε. The term \sharp\_γ(\varphi1, . . .,

Noah Linden, Sandu Popescu, Anthony J. Short, Andreas Winter

The circumstances under which a system reaches thermal equilibrium, and how to derive this from basic dynamical laws, has been a major question from the very beginning of thermodynamics and statistical mechanics. Despite considerable progress, it remains an open problem. Motivated by this issue, we address the more general question of equilibration. We prove

J. Kalinowski, S. F. King, J. P. Roberts

We discuss the neutralino dark matter within classes of extended supersymmetric models, referred to as the USSM, containing one additional SM singlet Higgs plus an extra Z&#39;, together with their superpartners the singlino and bino&#39;.

Agnes Antal, Titusz Feher, Andras Janossy, Erzsebet Tatrai-Szekeres

The layered organic compounds, kappa-(BEDT-TTF)_2Cu[N(CN)_2X (X=Cl, Br) are metals at ambient temperatures. At low temperatures, the Cl compound is a weakly ferromagnetic Mott insulator while the isostructural Br compound is a superconductor. We find by conduction electron spin resonance (CESR) and antiferromagnetic resonance (AFMR) an extreme anisotropy of

Udo Schwingenschloegl, Raymond Fresard, Volker Eyert

We apply density functional theory and the augmented spherical wave method to analyze the electronic structure of V2O3 in the vicinity of an interface to Al2O3. The interface is modeled by a heterostructure setup of alternating vanadate and aluminate slabs. We focus on the possible modifications of the V2O3 electronic states in this geometry, induced by the

Petr Kulish, Vladimir Lyakhovsky

The recursion relations of branching coefficients $k_ξ^{(μ)}$ for a module $L_{\frak{g}\downarrow \frak{h}}^μ$ reduced to a Cartan subalgebra $\frak{h}$ are transformed in order to place the recursion shifts $γ\in Γ_{\frak{a}\subset \frak{h}}$ into the fundamental Weyl chamber. The new ensembles $FΨ$ (the &#34;folded fans&#34;) of shifts were constructed and

Christoph Raeth, Roberto A. Monetti

The method of surrogates is widely used in the field of nonlinear data analysis for testing for weak nonlinearities. The two most commonly used algorithms for generating surrogates are the amplitude adjusted Fourier transform (AAFT) and the iterated amplitude adjusted Fourier transfom (IAAFT) algorithm. Both the AAFT and IAAFT algorithm conserve the amplitud

Monica Conti, Veronica Felli

We deal with strongly competing multispecies systems of Lotka-Volterra type with homogeneous Neumann boundary conditions in dumbbell-like domains. Under suitable non-degeneracy assumptions, we show that, as the competition rate grows indefinitely, the system reaches a state of coexistence of all the species in spatial segregation. Furthermore, the limit conf

Luca Angelani, Roberto Di Leonardo, Giancarlo Ruocco

Micromotors pushed by biological entities, like motile bacteria, constitute a fascinating way to convert chemical energy into mechanical work at the micrometer scale. Here we show, by using numerical simulations, that a properly designed asymmetric object can be spontaneously set into the desired motion when immersed in a chaotic bacterial bath. Our findings

The ICARUS Collaboration, A. Ankowski

We discuss the ICARUS T600 detector capabilities in electromagnetic shower reconstruction through the analysis of a sample of 212 events, coming from the 2001 Pavia surface test run, of hadronic interactions leading to the production of $π^{0}$ mesons. Methods of shower energy and shower direction measurements were developed and the invariant mass of the pho

C. -O. Gullström, A. Kupść, A. Rusetsky

A realistic estimate of the cusp effect in the eta->3pi0 decay is required for the forthcoming high precision experiments. The predictions for the size of this effect are given within the framework of nonrelativistic effective field theory.

N. Michel

As nuclear wave functions have to obey the Pauli principle, potentials issued from reaction theory or Hartree-Fock formalism using finite-range interactions contain a non-local part. Written in coordinate space representation, the Schrodinger equation becomes integro-differential, which is difficult to solve, contrary to the case of local potentials, where i

Gemma De las Cuevas, Wolfgang Dür, Maarten Van den Nest, Hans J. Briegel

We study mappings between distinct classical spin systems that leave the partition function invariant. As recently shown in [Phys. Rev. Lett. 100, 110501 (2008)], the partition function of the 2D square lattice Ising model in the presence of an inhomogeneous magnetic field, can specialize to the partition function of any Ising system on an arbitrary graph. I

S. Antoniou, S. Lambropoulou

In this paper we try to establish a connection between a three-dimensional Lotka--Volterra dynamical system and two-dimensional topological surgery. There are many physical phenomena exhibiting two-dimensional topological surgery through a `hole drilling&#39; process. By our connection, such phenomena may be modelled mathematically by the above dynamical sys

Eric Emtander, Fatemeh Mohammadi, Somayeh Moradi

We consider Stanley--Reisner rings $k[x_1,...,x_n]/I(\mc{H})$ where $I(\mc{H})$ is the edge ideal associated to some particular classes of hypergraphs. For instance, we consider hypergraphs that are natural generalizations of graphs that are lines and cycles, and for these we compute the Betti numbers. We also generalize upon some known results about chordal

P. Reig, J. M Torrejon, I. Negueruela, P. Blay

The source 4U 2206+54 is one of the most enigmatic high-mass X-ray binaries. In spite of intensive searches, X-ray pulsations have not been detected in the time range 0.001-1000 s. A cyclotron line at ~30 keV has been suggested by various authors but never detected with significance. The stellar wind of the optical companion is abnormally slow. The orbital p

F. Kh. Abdullaev, A. A. Abdumalikov, R. M. Galimzyanov

We study modulational instability of matter-waves in Bose-Einstein condensates (BEC) under strong temporal nonlinearity-management. Both BEC in an optical lattice and homogeneous BEC are considered in the framework of the Gross-Pitaevskii equation, averaged over rapid time modulations. For a BEC in an optical lattice, it is shown that the loop formed on a di

Sz. Csizmadia, E. Illes-Almar, T. Borkovits

BP Vulpeculae is a bright eclipsing binary system showing apsidal motion. It was found in an earlier study that it shows retrograde apsidal motion which contradicts theory. In this paper we present the first $BV$ light curve of the system and its light curve solution as well as seven new times of the minima from the years 1959-1963. This way we could expande

Gregory Soyez

From dedicated QCD studies to new physics background estimation, jets will be everywhere at the LHC. In these proceedings, we discuss two important recent series of improvements. In the first one, we introduce new algorithms and new implementations of previously existing algorithms, in order to cure limitations of their predecessors and to satisfy fundamenta

Marco Baumgartl

This thesis investigates correspondences between open and closed strings. This is done on the level of coupled open-closed moduli spaces and from a string field theoretic point of view. The construction of boundary string field theory on Wess-Zumino-Witten models leads to a conjecture on closed string backgrounds appearing as non-local operators in open stri

J. M. Oliveira

The Magellanic Clouds offer unique opportunities to study star formation both on the global scales of an interacting system of gas-rich galaxies, as well as on the scales of individual star-forming clouds. The interstellar media of the Small and Large Magellanic Clouds and their connecting bridge, span a range in (low) metallicities and gas density. This all

N. Lodieu, B. Burningham, N. C. Hambly, D. J. Pinfield

We present the discovery of two new late-T dwarfs identified in the UKIRT Infrared Deep Sky Survey (UKIDSS) Galactic Clusters Survey (GCS) Data Release 2 (DR2). These T dwarfs are nearby old T dwarfs along the line of sight to star-forming regions and open clusters targeted by the UKIDSS GCS. They are found towards the Alpha Per cluster and Orion complex, re

V. Petit, G. A. Wade, L. Drissen, T. Montmerle

In massive stars, magnetic fields are thought to confine the outflowing radiatively-driven wind, resulting in X-ray emission that is harder, more variable and more efficient than that produced by instability-generated shocks in non-magnetic winds. Although magnetic confinement of stellar winds has been shown to strongly modify the mass-loss and X-ray charact

Samuel Fiorini, Gianpaolo Oriolo, Laura Sanità, Dirk Oliver Theis

The symmetric Virtual Private Network Design (VPND) problem is concerned with buying capacity on links (edges) in a communication network such that certain traffic demands can be met. We investigate a natural generalization of VPND where the cost per unit of capacity may decrease if a larger amount of capacity is reserved (economies of scale principle). The

Carla Cacciari

The Gaia space project, planned for launch in 2011, is one of the ESA cornerstone missions, and will provide astrometric, photometric and spectroscopic data of very high quality for about one billion stars brighter than V=20. This will allow to reach an unprecedented level of information and knowledge on several of the most fundamental astrophysical issues,

Leonid V. Kovalev, Jani Onninen

We prove local and global invertibility of Sobolev solutions of certain differential inclusions which prevent the differential matrix from having negative eigenvalues. Our results are new even for quasiregular mappings in two dimensions.

Olfa Bejaoui

We investigate the equations of anisotropic axisymmetric incompressible viscous fluids in the exterior of a cylinder of $\R^3$, rotating around an inhomogeneous vector $B(t, r)$. We prove uniform local existence with respect to the Rossby number in suitable anisotropic Sobolev spaces. We also obtain the propagation of the isotropic Sobolev regularity.

Frédéric Hélein

In this text we expound recent results by Idrisse Khemar on the construction of various geometric completely integrable systems generalizing the structure of Hamiltonian stationary Lagrangian surfaces (HSLS) discovered by F. Hélein and P. Romon. We first explain that, for surfaces in a 4-dimensional Euclidean space, the HSLS are a particular case of a more g

I. Biscardi, G. Raimondo, M. Cantiello, E. Brocato

We measure F814W Surface Brightness Fluctuations (SBFs) for a sample of distant shell galaxies observed with the Advanced Camera for Survey (ACS) on board of HST. To evaluate the distance at galaxies, theoretical SBF magnitudes for the ACS@HST filters are computed for single burst stellar populations covering a wide range of ages (t=1.5-14 Gyr) and metallici

Oskar Hallatschek, Pascal Hersen, Sharad Ramanathan, David R. Nelson

Competition between random genetic drift and natural selection plays a central role in evolution: Whereas non-beneficial mutations often prevail in small populations by chance, mutations that sweep through large populations typically confer a selective advantage. Here, however, we observe chance effects during range expansions that dramatically alter the gen

Sebastian Scheffler

We investigate ultraviolet fixed points in the real-time evolution of non-Abelian gauge fields. Classical-statistical lattice simulations reveal equal-time correlation functions with a spectral index 3/2. Analytical understanding of this result is achieved by employing a 2PI- loop expansion for the quantum theory.

Louis Leung

In 2002 Haviv gave a way of assigning Lie tensors to directed trivalent graphs. Weight systems on oriented chord idagrams modulo 6T can then be constructed from such tensors. In this paper we give explicit combinatorial formulas of weight systems using Manin triples constrcted from classical Lie algebras. We then compose these oriented weight systems with th

W. James Stirling

Parton distribution functions (pdfs) are an important ingredient for LHC phenomenology. Recent progress in determining pdfs from global analyses is reviewed, and some of the most important outstanding issues are highlighted. Particular attention is paid to the precision with which predictions for LHC `standard-candle&#39; cross sections can be made, and also

T. Nakamura, Y. Fukuda, A. Yogo, M. Tampo

Coulomb implosion mechanism of the negatively charged ion acceleration in laser plasmas is proposed. When a cluster target is irradiated by an intense laser pulse and the Coulomb explosion of positively charged ions occurs, the negative ions are accelerated inward. The maximum energy of negative ions is several times lower than that of positive ions. The the

Andre Ahlbrecht, Lachezar S. Georgiev, Reinhard F. Werner

We give a general proof for the existence and realizability of Clifford gates in the Ising topological quantum computer. We show that all quantum gates that can be implemented by braiding of Ising anyons are Clifford gates. We find that the braiding gates for two qubits exhaust the entire two-qubit Clifford group. Analyzing the structure of the Clifford grou

Dmitri V. Gal'tsov, Nikolai G. Scherbluk

Recently we suggested a solution generating technique for five-dimensional supergravity with three Abelian vector fields based on the hidden SO(4,4) symmetry of the three-dimensionally reduced theory. This technique generalizes the $G_{2(2)}$ generating technique developed earlier for minimal 5D supergravity (A. Bouchareb, G. Cl\'ement, C-M. Chen, D. V. Gal'

Lachezar S. Georgiev

We show that the braid-group extension of the monodromy-based topological quantum computation scheme of Das Sarma et al. can be understood in terms of the universal R matrix for the Ising model giving similar results to those obtained by direct analytic continuation of multi-anyon Pfaffian wave functions. It is necessary, however, to take into account the pr

Molin Liu, Jianbo Lu, Yuanxing Gui

Based on the 4D momentum, the influence of quintessence on the gravitational frequency shift and the deflection of light are examined in modified Schwarzschild space. We find that the frequency of photon depends on the state parameter of quintessence $w_q$: the frequency increases for $-1<w_q<-1/3$ and decreases for $-1/3<w_q<0$. Meanwhile, we adopt an integ

David Arroyo, Gonzalo Alvarez, José María Amigó

The work described in this paper can be interpreted as an application of the order patterns of symbolic dynamics when dealing with unimodal maps. Specifically, it is shown how Gray codes can be used to estimate the probability distribution functions (PDFs) of the order patterns of parametric unimodal maps. Furthermore, these PDFs depend on the value of the p

Z. D. Zhang

This is a Response to a recent Comment [F.Y. Wu et al., Phil. Mag. 88, 3093 (2008), arXiv:0811.3876] on the conjectured solution of the three-dimensional (3D) Ising model [Z.D. Zhang, Phil. Mag. 87, 5309 (2007), arXiv:0705.1045]. Several points are made: 1) Conjecture 1, regarding the additional rotation, is understood as performing a transformation for smoo

Jean-Baptiste Le Bouquin, Roberto Abuter, Pierre Haguenauer, Bertrand Bauvir

At the Very Large Telescope Interferometer, the purpose of the fringe-tracker FINITO is to stabilize the optical path differences between the beams, allowing longer integration times on the scientific instruments AMBER and MIDI. Our goal is to demonstrate the potential of FINITO for providing H-band interferometric visibilities, simultaneously and in additio

Valmir C. Barbosa, Raul Donangelo, Sergio R. Souza

Natural selection and random drift are competing phenomena for explaining the evolution of populations. Combining a highly fit mutant with a population structure that improves the odds that the mutant spreads through the whole population tips the balance in favor of natural selection. The probability that the spread occurs, known as the fixation probability,

Luciano Rezzolla

Over the last few years enormous progress has been made in the numerical description of the inspiral and merger of binary black holes. A particular effort has gone into the modelling of the physical properties of the final black hole, namely its spin and recoil velocity, as these quantities have direct impact in astrophysics, cosmology and, of course, genera

Gesualdo Scutari, Daniel P. Palomar, Sergio Barbarossa

This paper considers the non-cooperative maximization of mutual information in the vector Gaussian interference channel in a fully distributed fashion via game theory. This problem has been widely studied in a number of works during the past decade for frequency-selective channels, and recently for the more general MIMO case, for which the state-of-the art r

B. Shapiro, M. Tater

The classical Heun equation has the form {Q(z) d^2/dz^2 +P(z) d/dz +V(z)}S(z)=0 where Q(z) is a cubic, P(z) at most quadratic and V(z) linear polynomials resp. In the second half of the 19-th century E.Heine and T.STieltjes initiated the study of the set of all V(z) such that the above equation has a polynomial solution S(z) of a given degree n. The main goa

Delphine Féral, Sandrine Péché

We consider large complex random sample covariance matrices obtained from &#34;spiked populations&#34;, that is when the true covariance matrix is diagonal with all but finitely many eigenvalues equal to one. We investigate the limiting behavior of the largest eigenvalues when the population and the sample sizes both become large. Under some conditions on mo

Ying Chen

This work presents a new phenomenological description of QCD vacuum where the color background field is depicted by a constant parallel vector with amplitude proportional to $σ\sim 0.28 GeV^2$. The familiar Regge relation can be derived directly in a classic meaning. A new mass formula of hadrons are conjectured to give a very consistent description of hadro

Gregory Geneste

Using Molecular Dynamics simulations based on the effective hamiltonian developed by Zhong, Vanderbilt and Rabe [Phys. Rev. Lett. {\bf 73}, 1861 (1994)] (and fitted on first-principles calculations only), the technique of the thermodynamic integration is applied to barium titanate. It allows to compute the difference of free energy between macroscopic states

Zhi-Qing Zhang, Zhen-Jun Xiao

Based on the assumption of two-quark structure of the scalar meson $f_0(980)$, we calculate the branching ratios and CP-violating asymmetries for the four $B \to f_0(980)π$ and $B \to f_0(980)\etapp$ decays by employing the perturbative QCD (pQCD) factorization approach. The leading order pQCD predictions for branching ratios are, $Br(B^-\to f_0(980) π^-)\si

Pierre Mozer, Jocelyne Troccaz, Dan Stoianovici

PURPOSE OF REVIEW: Robot-assisted laparoscopic surgery in urology has gained immense popularity with the daVinci system, but a lot of research teams are working on new robots. The purpose of this study is to review current urologic robots and present future development directions. RECENT FINDINGS: Future systems are expected to advance in two directions: imp

Jing Liu, Rui Zhou, Zhen-Jun Xiao

By employing the perturbative QCD(pQCD) factorization approach, we calculated the partial next-to-leading order (NLO) contributions to $B_s \to P P$ decays ($P= π, K, \etap $), coming from the QCD vertex corrections, the quark-loops and the chromo-magnetic penguins. we found numerically that (a) for three measured decays $\bar{B}_s \to K^+ π^-, K^+K^-$ and $

Tobias Abenius

Counting and classifying blood cells is an important diagnostic tool in medicine. Support Vector Machines are increasingly popular and efficient and could replace artificial neural network systems. Here a method to classify blood cells is proposed using SVM. A set of statistics on images are implemented in C++. The MPEG-7 descriptors Scalable Color Descripto

Ming Li, Shao-Ming Fei, Zhi-Xi Wang

We study the normal form of multipartite density matrices. It is shown that the correlation matrix (CM) separability criterion can be improved from the normal form we obtained under filtering transformations. Based on CM criterion the entanglement witness is further constructed in terms of local orthogonal observables for both bipartite and multipartite syst

Yan Wang, Frederick A. Jenet, Teviet Creighton, Richard H. Price

If a pulsar orbits a supermassive black hole, the timing of pulses that pass close to the hole will show a variety of strong field effects. To compute the intensity and timing of pulses that have passed close to a nonrotating black hole we introduce here a simple formalism based on two &#34;universal functions,&#34; one for the bending of photon trajectories

Ilham Chakir, Maurice Pouzet

We characterize well-founded algebraic lattices by means of forbidden subsemilattices of the join-semilattice made of their compact elements. More specifically, we show that an algebraic lattice $L$ is well-founded if and only if $K(L)$, the join-semilattice of compact elements of $L$, is well-founded and contains neither $[ω]^{<ω}$, nor $\underlineΩ(ω^*)$ a

V. U. Nazarov, G. Vignale, Y. -C. Chang

The dynamical exchange-correlation kernel $f_{xc}$ of a non-uniform electron gas is an essential input for the time-dependent density functional theory of electronic systems. The long-wavelength behavior of this kernel is known to be of the form $f_{xc}= α/q^2$ where $q$ is the wave vector and $α$ is a frequency-dependent coefficient. We show that in the lim

R. K. Ulrich, L. Bertello, J. E. Boyden, L. Webster

This study based on longitudinal Zeeman effect magnetograms and spectral line scans investigates the dependence of solar surface magnetic fields on the spectral line used and the way the line is sampled in order to estimate the magnetic flux emerging above the solar atmosphere and penetrating to the corona from magnetograms of the Mt. Wilson 150-foot tower s

Winfried Zimdahl

Interactions between dark matter and dark energy with a given equation of state are known to modify the cosmic dynamics. On the other hand, the strength of these interactions is subject to strong observational constraints. Here we discuss a model in which the transition from decelerated to accelerated expansion of the Universe arises as a pure interaction ph

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

Like high Tc cuprates, the newly discovered iron based superconductors lie in close proximity to a magnetically ordered parent phase. However, while the magnetic order in parent cuprates is known to derive from a spin-spin local superexchange interaction, a plethora of experiments including neutron scattering have so far been unable to conclusively resolve w

Muhammad Mostafa Monowar, Md. Obaidur Rahman, Al-Sakib Khan Pathan, Choong Seon Hong

Heterogeneous applications could be assimilated within the same wireless sensor network with the aid of modern motes that have multiple sensor boards on a single radio board. Different types of data generated from such types of motes might have different transmission characteristics in terms of priority, transmission rate, required bandwidth, tolerable packe

Dirk Englund, Hatice Altug, Jelena Vuckovic

We measure the lasing dynamics of single and coupled photonic crystal nanocavity array lasers fabricated in the indium gallium arsenide phosphide material system. Under short optical excitation, single cavity lasers produce pulses as fast as 11 ps (FWHM), while coupled cavity lasers show significantly longer lasing duration which is not explained by a simple

Misty C. Bentz, Bradley M. Peterson, Richard W. Pogge, Marianne Vestergaard

We investigate the relationship between black hole mass and bulge luminosity for AGNs with reverberation-based black hole mass measurements and bulge luminosities from two-dimensional decompositions of Hubble Space Telescope host galaxy images. We find that the slope of the relationship for AGNs is 0.76-0.85 with an uncertainty of ~0.1, somewhat shallower th

Misty C. Bentz, Bradley M. Peterson, Hagai Netzer, Richard W. Pogge

We present high-resolution HST images of all 35 AGNs with optical reverberation-mapping results, which we have modeled to create a nucleus-free image of each AGN host galaxy. From the nucleus-free images, we determine the host-galaxy contribution to ground-based spectroscopic luminosity measurements at 5100A. After correcting the luminosities of the AGNs for

Jimmy Tseng

For any real number \t, the set of all real numbers x for which there exists a constant c(x) > 0 such that \inf_{p \in \ZZ} |\t q - x - p| \geq c(x)/|q| for all q in \ZZ {0} is an 1/8-winning set.

Michael H. Freedman

I would claim that we do not have a suitably general definition of what a topological phase is, or more importantly, any robust understanding of how to enter one even in the world of mathematical models. The latter is, of course, the more important issue and the main subject of this note. But a good definition can sharpen our thinking and a poor definition c

Constantinos Daskalakis

We present a novel polynomial time approximation scheme for two-strategy anonymous games, in which the players&#39; utility functions, although potentially different, do not differentiate among the identities of the other players. Our algorithm computes an $eps$-approximate Nash equilibrium of an $n$-player 2-strategy anonymous game in time $poly(n) (1/eps)^

Éamonn D. Murray, David Vanderbilt

Recent work suggested that head-to-head and tail-to-tail domain walls could be induced to form in ferroelectric superlattices by introducing compensating &#34;delta doping&#34; layers via chemical substitution in specified atomic planes [Phys. Rev. B 73, 020103(R), 2006]. Here we investigate a variation of this approach in which superlattices are formed of a

M. Poggio, H. J. Mamin, C. L. Degen, M. H. Sherwood

We demonstrate nuclear double resonance for nanometer-scale volumes of spins where random fluctuations rather than Boltzmann polarization dominate. When the Hartmann-Hahn condition is met in a cross-polarization experiment, flip-flops occur between two species of spins and their fluctuations become coupled. We use magnetic resonance force microscopy to measu

Meijiao Guan

In this paper we prove the existence and local uniqueness of stationary states for the nonlinear Dirac equation \[ i \sum_{j=0}^{3} \ga^j \pd_j ψ- mψ+ F(\barψψ)ψ=0 \] where $ m >0$ and $ F(s) = |s|^θ$ for $ 1\leq θ< 2.$ More precisely we show that there exists $\e_0 > 0$ such that for $ω\in(m - \e_0, m), $ there exists a solution $ ψ(t,x) = e^{-iωt}ϕ_ω(x), x

K. J. H. Law, P. G. Kevrekidis, V. Koukouloyannis, I. Kourakis

We consider a prototypical dynamical lattice model, namely, the discrete nonlinear Schroedinger equation on nonsquare lattice geometries. We present a systematic classification of the solutions that arise in principal six-lattice-site and three-lattice-site contours in the form of both discrete multipole solitons and discrete vortices. Additionally to identi

Jin-ichi Itoh, Joseph O&#39;Rourke, Costin Vîlcu

We extend the notion of a star unfolding to be based on a simple quasigeodesic loop Q rather than on a point. This gives a new general method to unfold the surface of any convex polyhedron P to a simple, planar polygon: shortest paths from all vertices of P to Q are cut, and all but one segment of Q is cut.

Mario A. Acero, Julien Lesgourgues

Although the MiniBooNE experiment has severely restricted the possible existence of light sterile neutrinos, a few anomalies persist in oscillation data, and the possibility of extra light species contributing as a subdominant hot (or warm) component is still interesting. In many models, this species would be in thermal equilibrium in the early universe and

Sergei Dubovsky, Leonardo Senatore, Giovanni Villadoro

We calculate the probability distribution for the volume of the Universe after slow-roll inflation both in the eternal and in the non-eternal regime. Far from the eternal regime the probability distribution for the number of e-foldings, defined as one third of the logarithm of the volume, is sharply peaked around the number of e-foldings of the classical inf

Roberto Venegeroles

Hamiltonian mixed systems with unbounded phase space are typically characterized by two asymptotic algebraic laws: decay of recurrence time statistics ($γ$) and superdiffusion ($β$). We conjecture the universal exponents $γ=β=3/2$ for trapping of trajectories to regular islands based on our analytical results for a wide class of area-preserving maps. For Ham

Lorenzo Fatibene, Raymond G. McLenaghan, Giovanni Rastelli, Shane N. Smith

It is shown that the second order symmetry operators for the Dirac equation on a general two-dimensional spin manifold may be expressed in terms of Killing vectors and valence two Killing tensors. The role of these operators in the theory of separation of variables for the Dirac equation is studied.

Germán A. Racca, José W. S. Vilas-Boas, Ramiro de la Reza

We used near-infrared 2MASS data to construct visual extinction maps of a sample of Southern Bok globules utilizing the NICE method. We derived radial extinction profiles of dense cores identified in the globules and analyzed their stability against gravitational collapse with isothermal Bonnor-Ebert spheres. The frequency distribution of the stability param

Dusko Pavlovic

In categorical quantum mechanics, classical structures characterize the classical interfaces of quantum resources on one hand, while on the other hand giving rise to some quantum phenomena. In the standard Hilbert space model of quantum theories, classical structures over a space correspond to its orthonormal bases. In the present paper, we show that classic

Zachariah B. Etienne, Yuk Tung Liu, Stuart L. Shapiro, Thomas W. Baumgarte

Black hole-neutron star (BHNS) binary mergers are candidate engines for generating both short-hard gamma-ray bursts (SGRBs) and detectable gravitational waves. Using our most recent conformal thin-sandwich BHNS initial data and our fully general relativistic hydrodynamics code, which is now AMR-capable, we are able to efficiently and accurately simulate thes

MiniBooNE Collaboration

The MiniBooNE Collaboration observes unexplained electron-like events in the reconstructed neutrino energy range from 200 to 475 MeV. With $6.46 \times 10^{20}$ protons on target, 544 electron-like events are observed in this energy range, compared to an expectation of $415.2 \pm 43.4$ events, corresponding to an excess of $128.8 \pm 20.4 \pm 38.3$ events. T

Pasha Zusmanovich

The Euler-Poincaré characteristic of a finite-dimensional Lie algebra vanishes. If we want to extend this result to Lie superalgebras, we should deal with infinite sums. We observe that a suitable method of summation, which goes back to Euler, allows to do that, to a certain degree. The mathematics behind it is simple, we just glue the pieces of elementary h

Paul S. Wesson

Massive particles on timelike paths in spacetime can be viewed as moving on null paths in a higher-dimensional manifold. This and other consequences follow from the use of Campbell&#39;s theorem to embed 4D general relativity in non-compactified 5D Kaluza-Klein theory. We now show that it is possible in principle to obtain the standard rule for quantization

Rick Durrett, Daniel Remenik

We investigate an interacting particle system inspired by the gypsy moth, whose populations grow until they become sufficiently dense so that an epidemic reduces them to a low level. We consider this process on a random 3-regular graph and on the $d$-dimensional lattice and torus, with $d\geq2$. On the finite graphs with global dispersal or with a dispersal