April 2010 arXiv papers — page 7

Isabella Novik, Ed Swartz

We investigate the face numbers of simplicial complexes with Buchsbaum vertex links, especially pseudomanifolds with isolated singularities. This includes deriving Dehn-Sommerville relations for pseudomanifolds with isolated singularities and establishing lower bound theorems when the singularities are also homologically isolated. We give formulas for the Hi

C. A. Swenson, A. Maxham, P. W. A. Roming, P. Schady

GRB 090926A was detected by both the GBM and LAT instruments on-board the Fermi Gamma-Ray Space Telescope. Swift follow-up observations began ~13 hours after the initial trigger. The optical afterglow was detected for nearly 23 days post trigger, placing it in the long lived category. The afterglow is of particular interest due to its brightness at late time

Sergey Postnikov, Madappa Prakash, James Lattimer

Gravitational waves from the final stages of inspiralling binary neutron stars are expected to be one of the most important sources for ground-based gravitational wave detectors. The masses of the components are determinable from the orbital and chirp frequencies during the early part of the evolution during which tidal effects provide small correction; howe

H. Bender, C. Stehle, S. Slama, R. Kaiser

Scattering of light at a distribution of scatterers is an intrinsically cooperative process, which means that the scattering rate and the angular distribution of the scattered light are essentially governed by bulk properties of the distribution, such as its size, shape, and density, although local disorder and density fluctuations may have an important impa

D. De Tommasi, G. Puglisi, G. Saccomandi, G. Zurlo

We propose a model to analyze the insurgence of pull-in and wrinkling failures in electroactive thin films. We take in consideration both cases of voltage and charge control, and study the role of prestretch and size of activated regions, which are essential in the analysis of realistic applications of EAPs. Based on simple geometrical and material assumptio

Toshikaze Kariyado, Masao Ogata

Single impurity problem in iron-pnictide superconductors is investigated by solving Bogoliubov-de Gennes (BdG) equation in the five-orbital model, which enables us to distinguish s$_{+-}$ and s$_{++}$ superconducting states. We construct a five-orbital model suitable to BdG analysis. This model reproduces the results of random phase approximation in the unif

Ludwik Dabrowski, Gherardo Piacitelli

A complete classification of the regular representations of the relations [T,X_j] = (i/k)X_j, j=1,...,d, is given. The quantisation of RxR^d canonically (in the sense of Weyl) associated with the universal representation of the above relations is intrinsically "radial", this meaning that it only involves the time variable and the distance from the or

P. Neumann, R. Kolesov, B. Naydenov, J. Beck

Realization of devices based on quantum laws might lead to building processors that outperform their classical analogues and establishing unconditionally secure communication protocols. Solids do usually present a serious challenge to quantum coherence. However, owing to their spin-free lattice and low spin orbit coupling, carbon materials and particularly d

Christophe Vandekerckhove, Benjamin Sonday, Alexei Makeev, Dirk Roose

We present a simple technique for the computation of coarse-scale steady states of dynamical systems with time scale separation in the form of a "wrapper" around a fine-scale simulator. We discuss how this approach alleviates certain problems encountered by comparable existing approaches, and illustrate its use by computing coarse-scale steady states

Paul Bryans, Peter R Young, George A Doschek

We have used the Extreme Ultraviolet Imaging Spectrometer (EIS) on the Hinode spacecraft to observe large areas of outflow near an active region. These outflows are seen to persist for at least 6 days. The emission line profiles suggest that the outflow region is composed of multiple outflowing components, Doppler-shifted with respect to each other. We have

Shripad Garge

A linear algebraic group G defined over a field k is said to be excellent if for every field extension L of k the anisotropic kernel of the group (G \otimes_k L) is defined over k. We prove that groups of type G_2 and F_4 are excellent over any field k of characteristic other than 2 and 3.

Edward McCann, Mikito Koshino

Since the lattices of ABA-stacked graphene multilayers with an even number of layers, as well as that of monolayer graphene, satisfy spatial-inversion symmetry, their electronic bands must be spin degenerate in the presence of time-inversion symmetry. In intrinsic monolayer and bilayer graphene, when symmetry is not broken by external fields, the only spin-o

S. Barišić, O. S. Barišić

The large U_d theory, based on the Emery three band model extended with the Ox-Oy hopping t_pp, is constructed for the metallic state of high-Tc cuprates, using the mapping on the slave fermion theory. The time-dependent diagrammatic theory in terms of the Cu-O hopping t_pd starts from the locally gauge invariant state with vanishing occupation of the Cu sta

R. Trinchero

A simple integral that illustrates the concepts of regularization, subtraction, renormalization and renormalization group employed in perturbative quantum field theory(PQFT) is considered.

Samir Datta, Raghav Kulkarni, Raghunath Tewari, N. V. Vinodchandran

We investigate the space complexity of certain perfect matching problems over bipartite graphs embedded on surfaces of constant genus (orientable or non-orientable). We show that the problems of deciding whether such graphs have (1) a perfect matching or not and (2) a unique perfect matching or not, are in the logspace complexity class \SPL. Since \SPL\ is c

Eduardo V. Castro, N. M. R. Peres, J. M. B. Lopes dos Santos, F. Guinea

Bilayer graphene -- two coupled single graphene layers stacked as in graphite -- provides the only known semiconductor with a gap that can be tuned externally through electric field effect. Here we use a tight binding approach to study how the gap changes with the applied electric field. Within a parallel plate capacitor model and taking into account screeni

Yuji Hirota

This paper is devoted to the study of Morita equivalence for twisted Poisson manifolds. We review some Morita invariants and prove that integrable twisted Poisson manifolds which are gauge equivalent are Morita equivalent. Moreover, we introduce the notion of weak Morita equivalence and show that if two twisted Poisson manifolds are weak Morita equivalent, t

Alexey L. Krugly

A model of a discrete pregeometry on a microscopic scale is introduced. This model is a finite network of finite elementary processes. The mathematical description is a d-graph that is a generalization of a graph. This is the particular case of a causal set. The aim of this study is to construct the particles as emergent structures. The particles in this mod

Lei Zhang, Jung Hoon Lee, Ardavan Oskooi, Amit Hochman

Fast surface integral equation (SIE) solvers seem to be ideal approaches for simulating 3-D nanophotonic devices, as these devices generate fields both in an interior channel and in the infinite exterior domain. However, many devices of interest, such as optical couplers, have channels that can not be terminated without generating reflections. Generating abs

N. L. Zaitsev, I. A. Nechaev, P. M. Echenique, E. V. Chulkov

We present a detailed study of a monolayer film of 3,4,9,10-perylene-tetracarboxylic acid dianhydride (PTCDA) on Ag(111) (the PTCDA/Ag(111) system). The study is done within density functional theory with the use of the periodic slab model. The slab is chosen to contain a PTCDA monolayer film on a silver thin film of different thicknesses (6, 9, and 12 layer

Christian P. Robert

"Evidence and Evolution: the Logic behind the Science" was published in 2008 by Elliott Sober. It examines the philosophical foundations of the statistical arguments used to evaluate hypotheses in evolutionary biology, based on simple examples and likelihood ratios. The difficulty with reading the book from a statistician's perspective is the rel

Jharana Rani Samal, Arun Kumar Pati, Anil Kumar

Linearity and unitarity are two fundamental tenets of quantum theory. Any consequence that follows from these must be respected in the quantum world. The no-cloning theorem and the no-deleting theorem are the consequences of the linearity and the unitarity. Together with the stronger no-cloning theorem they provide permanence to quantum information, thus, su

Andrea Kohlhase, Michael Kohlhase, Christoph Lange

We study the formalization of a collection of documents created for a Software Engineering project from an MKM perspective. We analyze how document and collection markup formats can cope with an open-ended, multi-dimensional space of primary and secondary classifications and relationships. We show that RDFa-based extensions of MKM formats, employing flexible

H. T. Cui, C. M. Wang, S. Z. Yuan

Multipartite entanglement, measured by the geometric entanglement(GE), is discussed for integer spin Valance-Bond-Solid (VBS) state respectively with periodic boundary condition(PBC) and open boundary condition(OBC) in this paper. The optimization in the definition of geometric entanglement can be reduced greatly by exploring the symmetry of VBS state, and t

Kenneth J. Falconer, Jonathan M. Fraser

Given a compact subset $F$ of $\mathbb{R}^2$, the visible part $V_θF$ of $F$ from direction $θ$ is the set of $x$ in $F$ such that the half-line from $x$ in direction $θ$ intersects $F$ only at $x$. It is suggested that if $\dim_H F \geq 1$ then $\dim_H V_θF = 1$ for almost all $θ$, where $\dim_H$ denotes Hausdorff dimension. We confirm this when $F$ is a se

G. Popping, I. Perez, A. Zurita

NGC 2903 is a nearby barred spiral with an active starburst in the center and Hii regions distributed along its bar. We aim to analyse the star formation properties in the bar region of NGC 2903 and study the links with the typical bar morphological features. A combination of space and ground-based data from the far-ultraviolet to the sub-millimeter spectral

I. Ya. Aref'eva, R. V. Gorbachev

Simple analytic solution to cubic Neveu-Schwarz String Field Theory including the $GSO(-)$ sector is presented. This solution is an analog of the Erler-Schnabl solution for bosonic case and one of the authors solution for the pure $GSO(+)$ case. Gauge transformations of the new solution to others known solutions for the $NS$ string tachyon condensation are c

R. D. Grouchy, R. J. Buta, H. Salo, E. Laurikainen

Nonbarred ringed galaxies are relatively normal galaxies showing bright rings of star formation in spite of lacking a strong bar. This morphology is interesting because it is generally accepted that a typical ring forms when material collects near a resonance, set up by the pattern speed of a bar or bar-like perturbation. Our goal in this paper is to examine

Hidetaka Kitayama

The purpose of this paper is to give an explicit dimension formula for the spaces of vector valued Siegel cusp forms of degree two with respect to a certain kind of arithmetic subgroups of the non-split Q-forms of Sp(2,R). We obtain our result by using Hashimoto and Ibukiyama's results in [HI80],[HI83] and Wakatsuki's formula in [Wak]. Our result is

Quansheng Ren, Kiran M. Kolwankar, Areejit Samal, Jürgen Jost

We study the dynamics of the structure of a formal neural network wherein the strengths of the synapses are governed by spike-timing-dependent plasticity (STDP). For properly chosen input signals, there exists a steady state with a residual network. We compare the motif profile of such a network with that of a real neural network of \emph{C. elegans} and ide

M. Sbragaglia, K. Sugiyama

We analyze a volumetric formulation of lattice Boltzmann for compressible thermal fluid flows. The velocity set is chosen with the desired accuracy, based on the Gauss-Hermite quadrature procedure, and tested against controlled problems in bounded and unbounded fluids. The method allows the simulation of thermohydrodyamical problems without the need to prese

R. Benzi, M. Bernaschi, M. Sbragaglia, S. Succi

We provide a clear evidence that a two species mesoscopic Lattice Boltzmann (LB) model with competing short-range attractive and mid-range repulsive interactions supports emergent Herschel-Bulkley (HB) rheology, i.e. a power-law dependence of the shear-stress as a function of the strain rate, beyond a given yield-stress threshold. This kinetic formulation su

Xin Wu, Yi Xie

Full general relativity requires that chaos indicators should be invariant in various spacetime coordinate systems for a given relativistic dynamical problem. On the basis of this point, we calculate the invariant Lyapunov exponents (LEs) for one of the spinning compact binaries in the conservative second post-Newtonian (2PN) Lagrangian formulation without t

Tim Ledwig, Vladimir Pascalutsa, Marc Vanderhaeghen

We deal with the problem of assigning electromagnetic moments to a quasi-stable particle (i.e., a particle with mass located at particle's decay threshold). In this case, an application of a small external electromagnetic field changes the energy in a non-analytic way, which makes it difficult to assign definitive moments. On the example of a spin-1/2 fi

Federico M. Pont, Omar Osenda, Pablo Serra

Resonance states of a two-electron quantum dot are studied using a variational expansion with both real basis-set functions and complex scaling methods. We present numerical evidence about the critical behavior of the density of states in the region where there are resonances. The critical behavior is signaled by a strong dependence of some features of the d

Aaron C Hurley, Ali Al-Radaideh, Bai Li, Uwe Aickelin

The radiofrequency (RF) transmit field is severely inhomogeneous at ultrahigh field due to both RF penetration and RF coil design issues. This particularly impairs image quality for sequences that use inversion pulses such as magnetization prepared rapid acquisition gradient echo and limits the use of quantitative arterial spin labeling sequences such as flo

Masoud Allahverdizadeh, Jutta Kunz, Francisco Navarro-Lerida

Employing higher order perturbation theory, we obtain charged rotating black holes in odd dimensions, where the Einstein-Maxwell Lagrangian may be supplemented with a Chern-Simons term. Starting from the Myers-Perry solutions, we use the electric charge as the perturbative parameter, and focus on extremal black holes with equal-magnitude angular momenta. For

Gregory Schehr, Satya N. Majumdar

We consider a one dimensional Lévy bridge x_B of length n and index 0 < α< 2, i.e. a Lévy random walk constrained to start and end at the origin after n time steps, x_B(0) = x_B(n)=0. We compute the distribution P_B(A,n) of the area A = \sum_{m=1}^n x_B(m) under such a Lévy bridge and show that, for large n, it has the scaling form P_B(A,n) \sim n^{-1-1/α} F

J. Maíz Apellániz

CONTEXT. Massive stars have high-multiplicity fractions, and many of them have still undetected components, thus hampering the study of their properties. AIMS. I study a sample of massive stars with high angular resolution to better characterize their multiplicity. METHODS. I observed 138 fields that include at least one massive star with AstraLux, a lucky i

Matthew A. Bershady, Marc A. W. Verheijen, Kyle B. Westfall, David R. Andersen

We present a performance analysis of the DiskMass Survey. The survey uses collisionless tracers in the form of disk stars to measure the surface-density of spiral disks, to provide an absolute calibration of the stellar mass-to-light ratio, and to yield robust estimates of the dark-matter halo density profile in the inner regions of galaxies. We find a disk

R. Nath, V. O. Garlea, A. I. Goldman, D. C. Johnston

Polycrystalline samples of Sr2Mn2CuAs2O2, Sr2Mn3As2O2, and Sr2Zn2MnAs2O2 were synthesized. Their temperature- and applied magnetic field-dependent structural, transport, thermal, and magnetic properties were characterized by means of x-ray and neutron diffraction, electrical resistivity rho, heat capacity, magnetization and magnetic susceptibility measuremen

Benjamin Jourdain, Bernard Lapeyre, Piergiacomo Sabino

This paper investigates the use of multiple directions of stratification as a variance reduction technique for Monte Carlo simulations of path-dependent options driven by Gaussian vectors. The precision of the method depends on the choice of the directions of stratification and the allocation rule within each strata. Several choices have been proposed but, e

Franck Butelle, Florent Hivert, Micaela Mayero, Frédéric Toumazet

The main goal of our work is to formally prove the correctness of the key commands of the SCHUR software, an interactive program for calculating with characters of Lie groups and symmetric functions. The core of the computations relies on enumeration and manipulation of combinatorial structures. As a first &#34;proof of concept&#34;, we present a formal proo

Luca Moscadelli, Ye Xu, Xi Chen

We derive accurate proper motions of the CH3OH 12 GHz masers towards the W3(OH) UCHII region, employing seven epochs of VLBA observations spanning a time interval of about 10 yr. The achieved velocity accuracy is of the order of 0.1 km/s, adequate to precisely measure the relative velocities of most of the 12 GHz masers in W3(OH), with amplitude varying in t

Paul Broussous, Vincent Sécherre, Shaun Stevens

Let F be a locally compact nonarchimedean local field. In this article, we extend to any inner form of GL(n) over F the notion of endo-class introduced by Bushnell and Henniart for GL(n,F). We investigate the intertwining relations of simple characters of these groups, in particular their preservation properties under transfer. This allows us to associate to

Amparo Baíllo, Juan Antonio Cuesta-Albertos, Antonio Cuevas

In the framework of supervised classification (discrimination) for functional data, it is shown that the optimal classification rule can be explicitly obtained for a class of Gaussian processes with &#34;triangular&#34; covariance functions. This explicit knowledge has two practical consequences. First, the consistency of the well-known nearest neighbors cla

Nikolaos Tsakiris, Michail Maragakis, Kosmas Kosmidis, Panos Argyrakis

We study the percolation properties of the growing clusters model. In this model, a number of seeds placed on random locations on a lattice are allowed to grow with a constant velocity to form clusters. When two or more clusters eventually touch each other they immediately stop their growth. The model exhibits a discontinuous transition for very low values o

Jeffrey D. Blanchard, Coralia Cartis, Jared Tanner

Compressed Sensing (CS) seeks to recover an unknown vector with $N$ entries by making far fewer than $N$ measurements; it posits that the number of compressed sensing measurements should be comparable to the information content of the vector, not simply $N$. CS combines the important task of compression directly with the measurement task. Since its introduct

Georges Meynet, Raphael Hirschi, Sylvia Ekstrom, Andre Maeder

(abridged) The three most iron poor stars presently known ([Fe/H] equal to -5.96, -5.4 and -4.75) are carbon-rich, they are called C-Rich Ultra-Metal Poor Stars (CRUMPS). The origin of their peculiar surface abundances is not understood. We propose a synthetic view of the different models so far proposed to explain the peculiar abundances observed at the sur

M. D. Taylor

Building upon earlier work in which axioms were formulated for multivariate measures of concordance, we examine properties of such measures. In particular, we examine the relations between the measure of concordance of an $n$-copula and the measures of concordance of the copula&#39;s marginals.

Bogdan Ion

We show that in characteristic zero all irreducible symmetrically braided Hopf algebras are of PBW type. Consequently, we obtain conditions for a braided Hopf algebra to be of PBW type as module over a braided Hopf subalgebra containing the coradical.

L. F. Caram, C. F. Caiafa, A. N. Proto, M. Ausloos

The dynamic behavior of a multiagent system in which the agent size $s_{i}$ is variable it is studied along a Lotka-Volterra approach. The agent size has hereby for meaning the fraction of a given market that an agent is able to capture (market share). A Lotka-Volterra system of equations for prey-predator problems is considered, the competition factor being

Daniel Burgarth, Koji Maruyama, Franco Nori

A number of many-body problems can be formulated using Hamiltonians that are quadratic in the creation and annihilation operators. Here, we show how such quadratic Hamiltonians can be efficiently estimated indirectly, employing very few resources. We find that almost all properties of the Hamiltonian are determined by its surface, and that these properties c

Arseni Goussev, Roman Schubert, Holger Waalkens, Stephen Wiggins

We review recent results on quantum reactive scattering from a phase space perspective. The approach uses classical and quantum versions of normal form theory and the perspective of dynamical systems theory. Over the past ten years the classical normal form theory has provided a method for realizing the phase space structures that are responsible for determi

Aman D. Sood, Rajeev K. Puri

We aim to study the role of momentum-dependent interactions in transverse flow as well as in its disappearance. For the present study, central collisions involving mass between 24 and 394 are considered. We find that momentum-dependent interactions have different impact in lighter colliding nuclei compared to heavier colliding nuclei. In lighter nuclei, the

Naoki Kubota

There is a condition (T&#39;), such that it is the necessary condition that a random walk in random environment is ballistic. Under this condition, we show the law of the iterated logarithm for a random walk in random environment.

Fabio Caccioli, Matteo Marsili

We study a simple model of an asset market with informed and non-informed agents. In the absence of non-informed agents, the market becomes information efficient when the number of traders with different private information is large enough. Upon introducing non-informed agents, we find that the latter contribute significantly to the trading activity if and o

G. S. Denicol, T. Koide, D. H. Rischke

We re-derive the equations of motion of dissipative relativistic fluid dynamics from kinetic theory. In contrast to the derivation of Israel and Stewart, which considered the second moment of the Boltzmann equation to obtain equations of motion for the dissipative currents, we directly use the latter&#39;s definition. Although the equations of motion obtaine

Marek Cygan, Marcin Pilipczuk

In this paper we merge recent developments on exact algorithms for finding an ordering of vertices of a given graph that minimizes bandwidth (the BANDWIDTH problem) and for finding an embedding of a given graph into a line that minimizes distortion (the DISTORTION problem). For both problems we develop algorithms that work in O(9.363^n) time and polynomial s

Serge Galam

Public debates driven by incomplete scientific data where nobody can claim absolute certainty, due to current state of scientific knowledge, are studied. The cases of evolution theory, global warming and H1N1 pandemic influenza are investigated. The first two are of controversial impact while the third is more neutral and resolved. To adopt a cautious balanc

Vesa Julin

In this paper the existence of an absolute minimizer for a functional \[ F(u,Ω) = \underset{x \in Ω}{\text{ess sup}} \, f (x, u(x), Du(x)) \] is proved by using Perron&#39;s method. The function is assumed to be quasiconvex and uniformly coercive. This completes the result by Champion, De Pascale and Prinari.

Kourosh Nozari, Siamak Akhshabi

Following our previous work in noncommutative braneworld inflation (arXiv:0911.4418), in this paper we use the smeared, coherent state picture of noncommutativity to study evolution of perturbations in a noncommutative braneworld scenario. We show that in this setup, the early stage of the universe evolution has a phantom evolution with imaginary effective s

Pekka Lahti, Juha-Pekka Pellonpää, Jussi Schultz

We consider the quantum optical eight-port homodyne detection scheme in the case that each of the associated photon detectors is assigned with a different quantum efficiency. We give a mathematically rigorous and strictly quantum mechanical proof of the fact that the measured observable (positive operator measure) in the high-amplitude limit is a smearing of

David A. Towers

Relationships between certain properties of maximal subalgebras of a Lie algebra $L$ and the structure of $L$ itself have been studied by a number of authors. Amongst the maximal subalgebras, however, some exert a greater influence on particular results than others. Here we study properties of those maximal subalgebras that contain Engel subalgebras, and of

Gonzalo A. Alvarez, Dieter Suter

The loss of coherence in quantum mechanical superposition states limits the time for which quantum information remains useful. Similarly, it limits the distance over which quantum information can be transmitted, resembling Anderson localization, where disorder causes quantum mechanical states to become localized. Here, we investigate in a nuclear spin-based

Krzysztof Sadlej, Eligiusz Wajnryb, Maria L. Ekiel-Jeżewska

Evolution of a suspension drop entrained by Poiseuille flow is studied numerically at a low Reynolds number. A suspension drop is modelled by a cloud of many non-touching particles, initially randomly distributed inside a spherical volume of a viscous fluid which is identical to the host fluid outside the drop. Evolution of particle positions and velocities

J. X. Zheng-Johansson

It is by the long established fact in experiment and theory that electromagnetic waves, here as one component of an IED particle, passing a double slit will undergo self inference each, producing at a detector plane fringed intensities. The wave generating point charge of a zero rest mass, as the other component of the particle, is maintained a constant ener

Atanas Marinov Atanassov

The situational analysis lies in the basis of space and ground-based experiment planning. It is connected with the use of complex computation models of environment and with verification of the restricting conditions, due to the character of the conducted experiments and the solved scientific tasks. The present work proposes a formulation of the situational a

César Domínguez, Julio Rubio

Computational content encoded into constructive type theory proofs can be used to make computing experiments over concrete data structures. In this paper, we explore this possibility when working in Coq with chain complexes of infinite type (that is to say, generated by infinite sets) as a part of the formalization of a hierarchy of homological algebra struc

David Mateo, Martí Pi, Manuel Barranco

We have studied the evolution of an excited electron bubble in superfluid 4He for several tens of picoseconds combining the dynamics of the liquid with an adiabatic evolution for the electron. The path followed by the excited bubble in its decay to the ground state is shown to strongly depend on pressure. While for pressures below 1 bar the 1P excited electr

C. Adloff, Y. Karyotakis, J. Repond, J. Yu

A prototype silicon-tungsten electromagnetic calorimeter for an ILC detector was tested in 2007 at the CERN SPS test beam. Data were collected with electron and hadron beams in the energy range 8 to 80 GeV. The analysis described here focuses on the interactions of pions in the calorimeter. One of the main objectives of the CALICE program is to validate the

Biruniy Fayzullaev

It is shown that Einstein gravitational equations and canonical equations following from the Dirac-Schwinger Hamiltonian in the Faddeev variables coincide. For proving of this at first, the Einstein equations has been rewritten in canonical variables, and after this, the time derivative of the generalized momenta of the gravitational field in Faddeev form ha

Patrick B Warren

A neutral ecology model is simulated on an island chain, in which neighbouring islands can exchange individuals but only the first island is able to receive immigrants from a metacommunity. It is found by several measures that biodiversity decreases along the chain, being highest for the first island. Subtle changes in taxon abundance distributions can be de

C B Prior, M A Berger

We discuss the appropriate techniques for modelling the geometry of open ended elastic polymer molecules. The molecule is assumed to have fixed endpoints on a boundary surface. In particular we discuss the concept of the winding number, a directional measure of the linking of two curves, which can be shown to be invariant to the set of continuous deformation

F. L. Forgerini, W. Figueiredo

We present some results of Monte Carlo simulations for the deposition of particles of different sizes on a two-dimensional substrate. The particles are linear, height one, and can be deposited randomly only in the two, $x$ and $y$ directions of the substrate, and occupy an integer number of cells of the lattice. We show there are three different regimes for

Elvira Di Nardo

A very simple closed-form formula for Sheppard&#39;s corrections is recovered by means of the classical umbral calculus. By means of this symbolic method, a more general closed-form formula for discrete parent distributions is provided and the generalization to the multivariate case turns to be straightforward. All these new formulae are particularly suited

Craig McNeile

I review how the determination of quark masses from lattice QCD can be used to study textures in quark mass matrices. This type of theory relates quark masses to CKM matrix elements. I demonstrate how the recent precision results from the HPQCD and MILC collaborations for quark masses can be used to test some of these ideas.

Tsuyoshi Kato, Satoshi Tsujimoto

We introduce some analytic relations on the set of partial differential equations of two variables. It relies on a new comparison method to give rough asymptotic estimates for solutions which obey different partial differential equations. It uses a kind of scale transform called tropical geometry which connects automata with real rational dynamics. Two diffe

Alexandru Constantinescu, Matteo Varbaro

The algebra of basic covers of a graph G, denoted by \A(G), was introduced by Juergen Herzog as a suitable quotient of the vertex cover algebra. In this paper we show that if the graph is bipartite then \A(G) is a homogeneous algebra with straightening laws and thus is Koszul. Furthermore, we compute the Krull dimension of \A(G) in terms of the combinatorics

Bruno Zambon, Roberto Franzosi

The classical model that describes the motion of an atom in a magnetic trap is solved in order to investigate the relationship between the failure of the usual adiabatic approximation assumption and the physical parameters of the trap. This allows to evaluate the effect that reversing of the bias field rotation produces on the vertical position of the atomic

Steven D. Bass

The proton spin puzzle has challenged our understanding of QCD for the last 20 years. We survey new developments in theory and experiment. The proton spin puzzle seems to be telling us about the interplay of valence quarks with chiral dynamics and the complex vacuum structure of QCD.

Henning Vahlbruch, Alexander Khalaidovski, Nico Lastzka, Christian Graef

The next upgrade of the GEO600 gravitational wave detector is scheduled for 2010 and will, in particular, involve the implementation of squeezed light. The required non-classical light source is assembled on a 1.5m^2 breadboard and includes a full coherent control system and a diagnostic balanced homodyne detector. Here, we present the first experimental cha

Facundo A. Gómez, Amina Helmi, Anthony G. A. Brown, Yang-Shyang Li

We model the formation of the Galactic stellar halo via the accretion of satellite galaxies onto a time-dependent semi-cosmological galactic potential. Our goal is to characterize the substructure left by these accretion events in a close manner to what may be possible with the {\it Gaia} mission. We have created a synthetic {\it Gaia} Solar Neighbourhood ca

Vladimir Vatutin

For multitype branching processes with immigration evolving in a random environment and producing a final product we find the tail distribution of the size of the final product accumulated in the system for a life period. Using this result we investigate the tail distribution of the busy periods of the branching type polling systems with random service disci

D. V. Vlasov, L. A. Apresyan, V. I. Krystob, T. V. Vlasova

The near threshold &#34;soft breakdown&#34; measurements of PVC films conductivity are investigated. In a wide range of external electric field strength for various rather thick (>20 mkm) PVC films the resistance shows strong nonlinearity and seems to enter high conductive state close to the breakdown threshold. For our &#34;thick&#34; films boundary conditi

M. G. Richer, J. A. López, Ma. -T. García-Díaz, D. M. Clark

We study the line widths in the [\ion{O}{3}]$λ$5007 and H$α$ lines for two groups of planetary nebulae in the Milky Way bulge based upon spectroscopy obtained at the Observatorio Astronómico Nacional in the Sierra San Pedro Mártir (OAN-SPM) using the Manchester Echelle Spectrograph. The first sample includes objects early in their evolution, having high H$β$

Masaru Shibata, Hirotaka Yoshino

Numerical-relativity simulation is performed for rapidly spinning black holes (BHs) in a higher-dimensional spacetime of special symmetries for the dimensionality $6 \leq d \leq 8$. We find that higher-dimensional BHs, spinning rapidly enough, are dynamically unstable against nonaxisymmetric bar-mode deformation and spontaneously emit gravitational waves, ir

Laurent Labonté, Philippe Roy, Dominique Pagnoux, Frédéric Louradour

The chromatic dispersion curve of the fundamental mode in small core microstructured fibres (SCMF) is both calculated using a Finite Element Method (FEM) and measured with a low coherence interferometric method. The great sensitivity of the chromatic dispersion to variations of the geometrical parameters of SCMFs (the pitch and the diameter) is pointed out.

Mikhail Zaslavskiy, Francis Bach, Jean-Philippe Vert

Graphs provide an efficient tool for object representation in various computer vision applications. Once graph-based representations are constructed, an important question is how to compare graphs. This problem is often formulated as a graph matching problem where one seeks a mapping between vertices of two graphs which optimally aligns their structure. In t

Stéphane Nonnenmacher

These notes present a recent approach to study the high-frequency eigenstates of the Laplacian on compact Riemannian manifolds of negative sectional curvature. The main result is a lower bound on the Kolmogorov-Sinai entropy of the semiclassical measures associated with sequences of eigenstates, showing that high-frequency eigenstates cannot be too localized

Hisao Yoshihara

For each linearly normal elliptic curve $C$ in $\mathbb P^3$, we determine Galois lines and their arrangement. The results are as follows: the curve $C$ has just six $V_4$-lines and in case $j(C)=1$, it has eight $Z_4$-lines in addition. The $V_4$-lines form the edges of a tetrahedron, in case $j(C)=1$, for each vertex of the tetrahedron, there exist just tw

Chung-Hou Chung, Tsung-Han Lee

We study the interference between the Fano and Kondo effects in a side-coupled double-quantum- dot system where one of the quantum dots couples to conduction electron bath while the other dot only side-couples to the first dot via antiferromagnetic (AF) spin exchange coupling. We apply both the perturbative renormalization group (RG) and numerical renormaliz

Xiao-Jie Xu, Xiang-Dong Li

The binding energy parameter $λ$ plays an important role in common envelope (CE) evolution. Previous works have already pointed out that $λ$ varies throughout the stellar evolution, though it has been adopted as a constant in most of the population synthesis calculations. We have systematically calculated the binding energy parameter $λ$ for both Population

Jianqing Fan, Yingying Li, Ke Yu

Portfolio allocation with gross-exposure constraint is an effective method to increase the efficiency and stability of selected portfolios among a vast pool of assets, as demonstrated in Fan et al (2008). The required high-dimensional volatility matrix can be estimated by using high frequency financial data. This enables us to better adapt to the local volat

Konstantin Borovkov, Serguei Novak

It is well known that, under broad assumptions, the time-scaled point process of exceedances of a high level by a stationary sequence converges to a compound Poisson process as the level grows. The purpose of this note is to demonstrate that, for any given distribution G on the natural numbers, there exists a stationary sequence for which the compounding law

Felipe Rincón

The spinor variety is cut out by the quadratic Wick relations among the principal Pfaffians of an n x n skew-symmetric matrix. Its points correspond to n-dimensional isotropic subspaces of a 2n-dimensional vector space. In this paper we tropicalize this picture, and we develop a combinatorial theory of tropical Wick vectors and tropical linear spaces that ar

Robert Calderbank, Sina Jafarpour

We construct two families of deterministic sensing matrices where the columns are obtained by exponentiating codewords in the quaternary Delsarte-Goethals code $DG(m,r)$. This method of construction results in sensing matrices with low coherence and spectral norm. The first family, which we call Delsarte-Goethals frames, are $2^m$ - dimensional tight frames

Jong-Guk Bak, Andreas Seeger

We prove an endpoint version of the Stein-Tomas restriction theorem, for a general class of measures, and with a strengthened Lorentz space estimate. A similar improvement is obtained for Stein&#39;s estimate on oscillatory integrals of Carleson-Sjölin-Hörmander type and some spectral projection operators on compact manifolds, and for classes of oscillatory

Johanna Karouby, Robert Brandenberger

It was recently realized that matter modeled by the scalar field sector of the Lee-Wick Standard Model yields, in the context of a homogeneous and isotropic cosmological background, a bouncing cosmology. However, bouncing cosmologies induced by pressure-less matter are in general unstable to the addition of relativistic matter (i.e. radiation). Here we study

The CDF Collaboration, T. Aaltonen

Using data from 2.9/fb of integrated luminosity collected with the CDF II detector at the Tevatron, we search for resonances decaying into a pair of on-shell gauge bosons, WW or WZ, where one W decays into an electron and a neutrino, and the other boson decays into two jets. We observed no statistically significant excess above the expected standard model ba