May 2009 arXiv papers — page 21

Sergiy Silich, Guillermo Tenorio-Tagle, Ana Torres Campos, Casiana Munoz-Tunon

Here we discuss the mechanical feedback that massive stellar clusters provide to the interstellar medium of their host galaxy. We apply an analytic theory developed in a previous study for M82-A1 to a sample of 10 clusters located in the central zone of the starburst galaxy M82, all surrounded by compact and dense HII regions. We claim that the only way that

Tanmoy Chakraborty, Zhiyi Huang, Sanjeev Khanna

We consider the Item Pricing problem for revenue maximization in the limited supply setting, where a single seller with $n$ items caters to $m$ buyers with unknown subadditive valuation functions who arrive in a sequence. The seller sets the prices on individual items. Each buyer buys a subset of yet unsold items that maximizes her utility. Our goal is to de

S. Meloni, A. Buscarino, L. Fortuna, M. Frasca

We address the problem of how the survival of cooperation in a social system depends on the motion of the individuals. Specifically, we study a model in which Prisoner's Dilemma players are allowed to move in a two-dimensional plane. Our results show that cooperation can survive in such a system provided that both the temptation to defect and the velocit

K. D. Murphy, T. Yaqoob

The central engines of both type 1 and type 2 AGNs are thought to harbor a toroidal structure that absorbs and reprocesses high-energy photons from the central X-ray source. If the reprocessor is Compton-thick, the calculation of emission-line and continuum spectra that are suitable for direct fitting to X-ray data is challenging because the reprocessed emis

Ounsi El Daif, Gael Nardin, Taofiq K. Paraiso, Augustin Baas

We study the emission properties of confined polariton states in shallow zero-dimensional traps under non-resonant excitation. We evidence several relaxation regimes. For slightly negative photon-exciton detuning, we observe a nonlinear increase of the emission intensity, characteristic of carrier-carrier scattering assisted relaxation under strong-coupling

Jadranka Sekaric

The increasing size of the data recorded by the CDF and DØ experiments at the Tevatron collider at $\sqrt{s}=$ 1.96 TeV makes the diboson physics program more accessible for probes of the electroweak gauge structure in the Standard Model. Here we summarize the most recent measurements of the diboson cross sections and limits on the trilinear gauge boson coup

Eugene Polulyakh

We prove the following theorem. Let $U$ be a pseudo-harmonic function on a surface $M^2$. For a real valued continuous function $V : M^2 \to {\mathbb R}$ to be a conjugate pseudo-harmonic function of $U$ on $M^2$ it is necessary and sufficient that $V$ is open on level sets of $U$.

Ivone F. M. Albuquerque, Spencer R. Klein

Neutrino telescopes with cubic kilometer volume have the potential to discover new particles. Among them are next to lightest supersymmetric (NLSPs) and next to lightest Kaluza-Klein (NLKPs) particles. Two NLSPs or NLKPs will transverse the detector simultaneously producing parallel charged tracks. The track separation inside the detector can be a few hundre

M. Massi

Here we report on the VLBI discovery of solar-like extended streamers anchored on the two weak-line T Tauri stars of the binary system V773 Tau A. Covering the interbinary distance the 20 stellar radii extended streamers enter in collision during each stellar rotation with consequent occurrence of magnetic reconnection. Thermal electrons confined in the stre

Italo J. Dejter

A binary extended 1-perfect code $\mathcal C$ folds over its kernel via the Steiner quadruple systems associated with its codewords. The resulting folding, proposed as a graph invariant for $\mathcal C$, distinguishes among the 361 nonlinear codes $\mathcal C$ of kernel dimension $κ$ obtained via Solov'eva-Phelps doubling construction, where $9\geqκ\geq

A. Amara, A. Refregier, S. Paulin-Henriksson

Cosmic shear measurements rely on our ability to measure and correct the Point Spread Function (PSF) of the observations. This PSF is measured using stars in the field, which give a noisy measure at random points in the field. Using Wiener filtering, we show how errors in this PSF correction process propagate into shear power spectrum errors. This allows us

Sarah L. Martell, Graeme H. Smith

We present a comparison of CN bandstrength variations in the high-metallicity globular clusters NGC 6356 and NGC 6528 with those measured in the old open clusters NGC 188, NCG 2158 and NGC 7789. Star-to-star abundance variations, of which CN differences are a readily observable sign, are commonplace in moderate-metallicity halo globular clusters but are unse

Edward B. Jenkins

A study of gas-phase element abundances reported in the literature for 17 different elements sampled over 243 sight lines in the local part of our Galaxy reveals that the depletions into solid form (dust grains) are extremely well characterized by trends that employ only three kinds of parameters. One is an index that describes the overall level of depletion

J. Linder, T. Yokoyama, A. Sudbø

We study the spin-transfer torque and magnetoresistance of a ferromagnet$\mid$superconductor$\mid$ferromagnet spin-valve, allowing for an arbitrary magnetization misorientation and treating both s-wave and d-wave symmetries of the superconductor. We take fully into account Andreev reflection and also the spin-triplet correlations that are generated when the

G. Hagen, T. Papenbrock, D. J. Dean

The coupled-cluster wave function factorizes to a very good approximation into a product of an intrinsic wave function and a Gaussian for the center-of-mass coordinate. The width of the Gaussian is in general not identical to the oscillator length of the underlying single-particle basis. The quality of the separation can be verified by a simple procedure.

Patricia Hess

Let A denote the C*-algebra of bounded operators on L^2(RxS^1) generated by: (a) multiplications by smooth functions on S^1; (b) multiplications by continuous functions on the two point compactification of R; (c) multiplications by 2π-periodic continuous functions; (d) the operator L given by the inverse of the square root of the identity operator minus the

J. Sanjuan, A. Lobo, J. Ramos-Castro

Low-noise temperature measurements at frequencies in the milli-Hertz range are needed in the LISA and LISA PathFinder (LPF). The required temperature stability for LISA is around 10 uK/sqrt(Hz) at frequencies down to 0.1 mHz. In this paper we focus on the identification and reduction of a source of excess noise detected when measuring time-varying temperatur

William T. Reach, Jeremie Vaubaillon, Michael S. Kelley, Carey M. Lisse

During 2006 Mar - 2007 Jan, we used the IRAC and MIPS instruments on the Spitzer Space Telescope to study the infrared emission from the ensemble of fragments, meteoroids, and dust tails in the more than 3 degree wide 73P/Schwassmann-Wachmann 3 debris field. We also investigated contemporaneous ground based and HST observations. In 2006 May, 55 fragments wer

F. D. Colavecchia, G. Gasaneo, D. Mitnik

We study the double electronic emission by photon impact from He in the center of a spherical fullerene, which is modeled by a square-well shell. This system exhibits a manifold of avoided crossings as a function of the well depth, and present mirror colapses. However, this symmetry is broken in the triple differential cross section due to the delocalization

Alain-Yves Le Roux

By using the Hugoniot curve in detonics as a Riemann invariant of a velocity-pressure model, we get a conservative hyperbolic system similar to the Euler equations. The only differences are the larger value of the adiabatic constant (= 8.678 instead of 1.4 for gas dynamics) and the mass density replaced by a strain density depending on the pressure. The mode

Alan Carey, Matilde Marcolli, Adam Rennie

We continue an investigation initiated by Consani-Marcolli of the relation between the algebraic geometry of p-adic Mumford curves and the noncommutative geometry of graph C*-algebras associated to the action of the uniformizing p-adic Schottky group on the Bruhat-Tits tree. We reconstruct invariants of Mumford curves related to valuations of generators of t

Jose Manuel Gomez

In here we define the concept of fibered symmetric bimonoidal categories. These are roughly speaking fibered categories D->C whose fibers are symmetric monoidal categories parametrized by C and such that both D and C have a further structure of a symmetric monoidal category that satisfy certain coherences that we describe. Our goal is to show that we can cor

T. Ryabchikova, L. Fossati, D. Shulyak

The knowledge of accurate stellar parameters is a key stone in several fields of stellar astrophysics, such as asteroseismology and stellar evolution. Although the parameters can be derived both via spectroscopy and multicolor photometry, the obtained results are sometimes affected by systematic uncertainties. In this paper we present a self-consistent spect

Jose Manuel Gomez

In this note we show that there are no higher twistings for the Borel cohomology theory associated to G-equivariant K-theory over a point and for a compact Lie group G. Therefore, twistings over a point for this theory are classified by the group H^{1}(BG,Z/2)\x H^{3}(BG,Z)

P. F. Herskind, A. Dantan, M. Albert, J. P. Marler

We demonstrate a general technique to achieve a precise radial displacement of the nodal line of the radiofrequency (rf) field in a linear Paul trap. The technique relies on selective adjustment of the load capacitance of the trap electrodes, achieved through the addition of capacitors to the basic resonant rf-circuit used to drive the trap. Displacements of

Dhruv Mubayi

Let $F$ be a graph which contains an edge whose deletion reduces its chromatic number. We prove tight bounds on the number of copies of $F$ in a graph with a prescribed number of vertices and edges. Our results extend those of Simonovits, who proved that there is one copy of $F$, and of Rademacher, Erd\H os and Lovász-Simonovits, who proved similar counting

Thomas Wellens, Benoit Gremaud

We develop a diagrammatic theory for transport of waves in disordered media with weak nonlinearity. We first represent the solution of the nonlinear wave equation as a nonlinear Born series. From this, we construct nonlinear ladder and crossed diagrams for the average wave intensity. Then, we sum up the diagrammatic series completely, i.e. nonperturbatively

Melvyn B. Nathanson

This paper describes several classical constructions of thin bases of finite order in additive number theory, and, in particular, gives a complete presentation of a beautiful construction of J. W. S. Cassels of a class of polynomially asymptotic bases. Some open problems are also discussed.

Rachel D. Brown, Zellman Warhaft, Greg A. Voth

We measure acceleration statistics of neutrally buoyant spherical particles with diameter 0.4 < d/eta <27 in intense turbulence (400< R_lambda <815). High speed cameras image polystyrene tracer particles in a flow between counter-rotating disks. The measurements of acceleration variance, <a^2>, clearly resolve the transition from the tracer like behavior of

Benjamin Krueger, Massoud Najafi, Stellan Bohlens, Robert Froemter

The strength of the non-adiabatic spin torque is currently under strong debate, as its value differs by orders of magnitude as well in theoretical predictions as in measurements. Here, a measurement scheme is presented that allows to determine the strength of the non-adiabatic spin torque accurately and directly. Analytical and numerical calculations show th

T. N. Venkataramana B. Speh

We show that complementary series of SO(n,1) which are sufficiently close to a cohomological representation in the Fell topology, upon restriction to SO(n-1,1), contain discretely, complementary series for SO(n-1,1) which are also sufficiently close to cohomological representations. As a global application, we show that if the non-zero eigenvalues of the Lap

VERITAS Collaboration, V. A. Acciari, E. Aliu, T. Arlen

HESS J0632+057 is one of only two unidentified very-high-energy gamma-ray sources which appear to be point-like within experimental resolution. It is possibly associated with the massive Be star MWC 148 and has been suggested to resemble known TeV binary systems like LS I +61 303 or LS 5039. HESS J0632+057 was observed by VERITAS for 31 hours in 2006, 2008 a

P. J. Crockett, D. B. Jess, M. Mathioudakis, F. P. Keenan

Magnetic Bright Points (MBPs) in the internetwork are among the smallest objects in the solar photosphere and appear bright against the ambient environment. An algorithm is presented that can be used for the automated detection of the MBPs in the spatial and temporal domains. The algorithm works by mapping the lanes through intensity thresholding. A compass

A. Ambrosetti, F. Pederiva, E. Lipparini, S. Gandolfi

We introduce a variant to the Diffusion Monte Carlo algorithm that can be employed to study the effects of the Rashba interaction in a many electron systems. Because of the spin--orbit nature of Rashba interaction a standard algorithm cannot be applied and therefore a specific imaginary time spin dependent propagator has been developed and implemented follow

Luis A. Martinez-Vaquero, Gustavo Yepes, Yehuda Hoffman, Stefan Gottlöber

Using a suite of N-body simulations in different Cold Dark Matter (CDM) scenarios, with cosmological constant (\LCDM) and without (OCDM, SCDM), we study the Hubble flow (\sigh) in Local Volumes (LV) around Local Group (LG) like objects found in these simulations, and compare the numerical results with the most recent observations. We show that \LCDM and OCDM

C. Denker, J. Malindretos, B. Landgraf, A. Rizzi

Selective area growth of InN nanorods by plasma assisted molecular beam epitaxy is demonstrated. Molybdenum is found to be a suitable mask material at the low substrate temperature of 475 C needed for the growth of InN nanocolumns. The growth of arrays of single nanorods on a Si(111) substrate has been achieved with a thin molybdenum mask lithographically pa

Thomas L. Duvall,, Shravan M. Hanasoge

Measuring the depth variation of the meridional flows is important for understanding the solar cycle, at least according to a number of dynamo models. While attempting to extend the early observations of \citet{giles_thesis} of time-distance measurements of flow, we have stumbled upon some systematic errors that can affect these measurements: 1) the addition

Saulo Carneiro, Reza Tavakol

Standard cosmology poses a number of important questions. Apart from its singular origin, it possesses early and late accelerating phases required to account for observations. The vacuum energy has been considered as a possible way to resolve some of these questions. The vacuum energy density induced by free fields in an early de Sitter phase has earlier bee

Andreas Crivellin

I present results for the finite renormalization of the Cabibbo-Kobayashi-Maskawa (CKM) matrix induced by gluino--squark diagrams in the MSSM with non-minimal sources of flavour violation. Subsequently I derive bounds on the flavour--off--diagonal elements of the squark mass matrices by requiring that the radiative corrections to the CKM elements do not exce

M. Zaiser, P. Moretti, A. Konstantinidis, E. C. Aifantis

We investigate the roughening of shear cracks running along the interface between a thin film and a rigid substrate. We demonstrate that short-range correlated fluctuations of the interface strength lead to self-affine roughening of the crack front as the driving force (the applied shear stress/stress intensity factor) increases towards a critical value. We

Alain-Yves Le Roux

The sound propagation is usually described by a linear homogeneous wave equation, though the air flow in a duct is described by the gas dynamics equations, using a variable cross section, which corresponds to a non linear non homogneous system. The aim of this paper is to exhibit a common periodic solution to both models, with several free parameters such as

B. Berg, L. I. Plimak, A. Polkovnikov, M. K. Olsen

The applicability of the so-called truncated Wigner approximation (-W) is extended to multitime averages of Heisenberg field operators. This task splits naturally in two. Firstly, what class of multitime averages the -W approximates, and, secondly, how to proceed if the average in question does not belong to this class. To answer the first question we develo

I. R. Shein, A. L. Ivanovskii

The first-principles FLAPW-GGA calculations of the elastic properties of recently discovered superconducting LiFeAs are reported. The independent elastic constants (Cij), bulk modulus, compressibility, and shear modulus are evaluated and discussed. Additionally, numerical estimates of the elastic parameters of the polycrystalline LiFeAs ceramics are performe

Sylvain Schwartz, Gilles Feugnet, Maxence Rebut, Fabien Bretenaker

We report an experimental study of the 1064nm transition dipoles in neodymium doped yttrium aluminum garnet (Nd-YAG) by measuring the coupling constant between two orthogonal modes of a laser cavity for different cuts of the YAG gain crystal. We propose a theoretical model in which the transition dipoles, slightly elliptic, are oriented along the crystallogr

A. Pietarila, J. Hirzberger, V. Zakharov, S. K. Solanki

Context: Except for the Ca II resonance lines, fibrils are ubiquitously present in most high-resolution observations of chromospheric lines. Aims: We show that fibrils are also a prevailing feature in Ca II K, provided the spatial-resolution is sufficiently high. Methods: We present high spatial resolution observations of an active region in the Ca I} K line

Pierre Guillot

The cohomology ring of a finite group, with coefficients in a finite field, can be computed by a machine, as Carlson has showed. Here &#34;compute&#34; means to find a presentation in terms of generators and relations, and involves only the underlying (graded) ring. We propose a method to determine some of the extra structure: namely, Stiefel-Whitney classes

Alberto Accardi, Alessandro Bacchetta, Marc Schlegel

We review the study the Wandzura-Wilczek relation for the structure function g_2, with a particular attention on the connection with the framework of Transverse Momentum Dependent factorization. We emphasize that the relation is broken by two distinct twist-3 terms. In the light of these findings, we clarify what can be deduced from the available experimenta

Shlomo Gelaki, Deepak Naidu, Dmitri Nikshych

Let C be a fusion category faithfully graded by a finite group G and let D be the trivial component of this grading. The center Z(C) of C is shown to be canonically equivalent to a G-equivariantization of the relative center Z_D(C). We use this result to obtain a criterion for C to be group-theoretical and apply it to Tambara-Yamagami fusion categories. We a

I. Skillen, D. Pollacco, A. Collier Cameron, L. Hebb

We report the discovery of WASP-13b, a low-mass $ M_p = 0.46 ^{+ 0.06}_{- 0.05} M_J$ transiting exoplanet with an orbital period of $4.35298 \pm 0.00004$ days. The transit has a depth of 9 mmag, and although our follow-up photometry does not allow us to constrain the impact parameter well ($0 < b < 0.46$), with radius in the range $R_p \sim 1.06 - 1.21 R_J$

Alain-Yves Le Roux, Marie-Noëlle Le Roux

We propose to construct a temporary wave on the surface of the ocean, as a particular solution of the Saint-Venant equations with a source term involving the friction, whose shape is expected to mimic a rogue wave.

Orfeu Bertolami

We discuss the validity of general relativity at low-energy and relate the threshold below which the theory breaks down with the observed value of the cosmological constant. This suggests the existence of a mass scale of ${\cal O}(10^{-3}) eV$ and a putative violation of the equivalence principle at about $10^{-14}$ level.

Travis Gagie, Gonzalo Navarro, Yakov Nekrich

It is well-known that, given a probability distribution over $n$ characters, in the worst case it takes (Θ(n \log n)) bits to store a prefix code with minimum expected codeword length. However, in this paper we first show that, for any $0<ε<1/2$ with (1 / ε= \Oh{\polylog{n}}), it takes $\Oh{n \log \log (1 / ε)}$ bits to store a prefix code with expected code

Beat Röthlisberger, Jörg Lehmann, Daniel Loss

We present two ready-to-use numerical algorithms to evaluate convex-roof extensions of arbitrary pure-state entanglement monotones. Their implementation leaves the user merely with the task of calculating derivatives of the respective pure-state measure. We provide numerical tests of the algorithms and demonstrate their good convergence properties. We furthe

Rupert L. Frank, Enno Lenzmann

We establish uniqueness of ground states $u(x) \geq 0$ for the $L^2$-critical boson star equation $\sqrt{-Δ} u - (|x|^{-1} \ast |u|^2) u = -u$ in $\R^3$. The proof blends variational arguments with the harmonic extension to the halfspace $\R^4_+$. Apart from uniqueness, we also show radiality of ground states (up to translations) and the nondegeneracy of the

Ivo R. Seitenzahl, Casey A. Meakin, Don Q. Lamb, James W. Truran

We study the initiation of the detonation in the gravitationally confined detonation (GCD) model of Type Ia supernovae (SNe Ia). Initiation of the detonation occurs spontaneously in a region where the length scale of the temperature gradient extending from a flow (in which carbon burning is already occurring) into unburned fuel is commensurate to the range o

I. Ramirez, C. Allende Prieto, L. Koesterke, D. L. Lambert

We construct a 3D radiative-hydrodynamic model atmosphere of parameters Teff = 4820 K, log g = 4.5, and solar chemical composition. The theoretical line profiles computed with this model are asymmetric, with their bisectors having a characteristic C-shape and their core wavelengths shifted with respect to their laboratory values. The line bisectors span from

H. C. Walker, K. A. McEwen, P. Boulet, E. Colineau

We have made an extensive study of the magnetic and electrical properties of double-hexagonal closepacked NpPd3 and a range of U(1-x)Np(x)Pd3 compounds with x=0.01, 0.02, 0.05, and 0.50 using magnetization, magnetic susceptibility, electrical resistivity, and heat capacity measurements on polycrystalline samples, performed in the temperature range 2-300 K an

Bernard Host, Bryna Kra, Alejandro Maass

We characterize inverse limits of nilsystems in topological dynamics, via a structure theorem for topological dynamical systems that is an analog of the structure theorem for measure preserving systems. We provide two applications of the structure. The first is to nilsequences, which have played an important role in recent developments in ergodic theory and

T. Sidery, M. A. Alpar

We investigate dynamical coupling timescales of a neutron star&#39;s superfluid core, taking into account the interactions of quantized neutron vortices with quantized flux lines of the proton superconductor in addition to the previously considered scattering of the charged components against the spontaneous magnetization of the neutron vortex line. We compa

Éva Rácz, János Kertész, Zoltán Eisler

A wide range of natural and social phenomena result in observables whose distributions can be well approximated by a power-law decay. The well-known Hill estimator of the tail exponent provides results which are in many respects superior to other estimators in case the asymptotics of the distribution is indeed a pure power-law, however,systematic errors occu

Marc-Antoine Miville-Deschenes

With the increasing number of experiments dedicated to the observation of the Cosmic Microwave Background, interest on the detailed properties of the foreground Galactic emission has risen. In particular the focus is shifting towards polarized microwave emission with the goal of detecting signature from primordial gravitational waves and inflation. This revi

F. Bunea, M. H. Wegkamp, A. E. Ivanescu

This paper proposes and analyzes fully data driven methods for inference about the mean function of a stochastic process from a sample of independent trajectories of the process, observed at discrete time points and corrupted by additive random error. The proposed method uses thresholded least squares estimators relative to an approximating function basis. T

A. Chuvilin, J. C. Meyer, G. Algara-Siller, U. Kaiser

We present an atomic-resolution observation and analysis of graphene constrictions and ribbons with sub-nanometer width. Graphene membranes are studied by imaging side spherical aberration-corrected transmission electron microscopy at 80 kV. Holes are formed in the honeycomb-like structure due to radiation damage. As the holes grow and two holes approach eac

F. Fabrizi, H. C. Walker, L. Paolasini, F. de Bergevin

Non-resonant X-ray magnetic scattering has been used to study the magnetic structure of multiferroic TbMnO3 in its ferroelectric phase. Circularly polarized X-rays were combined with a full polarization analysis of the scattered beam to reveal important new information on the magnetic structure of this canonical multiferroic. An applied electric field is sho

Mahmut Ozer, Matjaz Perc, Muhammet Uzuntarla

We investigate the regularity of spontaneous spiking activity on Newman-Watts small-world networks consisting of biophysically realistic Hodgkin-Huxley neurons with a tunable intensity of intrinsic noise and fraction of blocked voltage-gated sodium and potassium ion channels embedded in neuronal membranes. We show that there exists an optimal fraction of sho

Jose A. de Azcarraga, J. M Izquierdo

We show that two cohomological properties of semisimple Lie algebras also hold for Filippov (n-Lie) algebras, namely, that semisimple n-Lie algebras do not admit non-trivial central extensions and that they are rigid i.e., cannot be deformed in Gerstenhaber sense. This result is the analogue of Whitehead&#39;s Lemma for Filippov algebras. A few comments abou

Emiliano De Simone, Laurent Marin

We consider the trace map associated with the silver ratio Schrodinger operator as a diffeomorphism on the invariant surface associated with a given coupling constant and prove that the non-wandering set of this map is hyperbolic if the coupling is sufficiently large. As a consequence, for this values of the coupling constant, the local and global Hausdorff

Xavier Gérard Viennot

The purpose of this paper is twofold. First we answer to a question asked by Steingrimsson and Williams about certain permutation tableaux: we construct a bijection between binary trees and the so-called Catalan tableaux. These tableaux are certain Ferrers (or Young) diagrams filled with some 0&#39;s and 1&#39;s, satisfying a certain hook condition, and are

Raphael Laguionie, Matthieu Rauch, Jean-Yves Hascoët

The current language for CNC programming is G-code which dates from the beginning of the eighties with the norm ISO 6983. With the new technologies, G-code becomes obsolete. It presents drawbacks that create a rupture in the numerical chain at the manufacturing step. A new standard, STEP-NC, aims to overtake these lacks. A STEP-NC file includes all the infor

Julia K. Becker, Marek A. Abramowicz, Peter L. Biermann

In the mass range of 1e15 g up to 1e26 g, primordial black holes (PBHs) as a possible contribution to the dark matter are still unexplored. In this contribution, we investigate the possibility of an electromagnetic signal from PBH interactions with astrophysical objects in the Galaxy. We find that a signal from passages cannot be observed, since, depending o

J. V. Clausen, H. Bruntt, A. Claret, A. Larsen

The influence of stellar activity on the fundamental properties of stars around and below 1 Msun is not well understood. We aim to determine absolute dimensions and abundances for the solar-type detached eclipsing binary V636 Cen. The results are based on uvby light curves, uvby-beta standard photometry, radial velocity observations, and high-resolution spec

E. Paolini, M. F. Flanagan, M. Chiani, M. P. C. Fossorier

A class of doubly-generalized low-density parity-check (D-GLDPC) codes, where single parity-check (SPC) codes are used as variable nodes (VNs), is investigated. An expression for the growth rate of the weight distribution of any D-GLDPC ensemble with a uniform check node (CN) set is presented at first, together with an analytical technique for its efficient

Vladimir Dogiel, Kwong-Sang Cheng, Dmitrii Chernyshov, Aya Bamba

We analyze the 6.4 keV line and continuum emission from the molecular cloud Sgr B2 and the source HESS J1745-303, which is supposed to be a complex of molecular gas. From the HESS results it follows that Sgr A is a source of high energy protons, which penetrate into molecular clouds producing there a TeV gamma-ray flux. We present arguments that Sgr A may al

N. T. Quang, N. T. Thuy

In this paper, we have studied the axiomatics of {\it Ann-categories} and {\it categorical rings.} These are the categories with distributivity constraints whose axiomatics are similar with those of ring structures. The main result we have achieved is proving the independence of the axiomatics of Ann-category definition. And then we have proved that after ad

Keith Hamilton, Peter Richardson, Jon Tully

A modified version of the CKKW matrix element merging algorithm is presented, suitable for use in an angular-ordered parton shower, using truncated showers and forced splittings. The algorithm is implemented in the Herwig++ Monte Carlo event generator for the benchmark process e+e- -> hadrons. Results are presented at parton and hadron levels, demonstrating

V. Dogiel, D. Breitschwerdt

We give a review of cosmic ray propagation models. It is shown that the development of the theory of cosmic ray origin leads inevitably to the conclusion that cosmic ray propagation in the Galaxy is determined by effective particle scattering, which is described by spatial diffusion. The Galactic Disk is surrounded by an extended halo, in which cosmic rays a

Katarina Borg Gyllenback

Very little has been explored about the narrative as a process when constructing entertainment for interactive media. Simultaneously, the interest in narrative vehicles increases while certain occupations, seeing the narrative as a structure, obscure the examination of the process of selecting, arranging and rendering story material. To correct this deficien

V. I. Yukalov, V. S. Bagnato

The problem of resonant generation of nonground-state condensates is addressed aiming at resolving the seeming paradox that arises when one resorts to the adiabatic representation. In this picture, the eigenvalues and eigenfunctions of a time-dependent Gross-Pitaevskii Hamiltonian are also functions of time. Since the level energies vary in time, no definite

Motohiko Ezawa

The trigonal zigzag nanodisk with size $N$ has $N$ localized spins. We investigate its thermodynamical properties with and without external leads. Leads are made of zigzag graphene nanoribbons or ordinary metallic wires. There exists a quasi-phase transition between the quasi-ferromagnet and quasi-paramagnet states, as signaled by a sharp peak in the specifi

Gideon Alexander, John Barley, Yuri Batygin, Steven Berridge

Full exploitation of the physics potential of a future International Linear Collider will require the use of polarized electron and positron beams. Experiment E166 at the Stanford Linear Accelerator Center (SLAC) has demonstrated a scheme in which an electron beam passes through a helical undulator to generate photons (whose first-harmonic spectrum extended

Wonmin Son, Vlatko Vedral

We compare the critical behavior of the ground state and the thermal state of the XX model. We analyze the full energy spectrum and the eigenstates to reconstruct the ground state and the thermally excited state. With the solutions, we discuss about several physical properties of the states, which are related to quantum phase transition, in various limits, a

Fridolin Okkels, Martin Dufva, Henrik Bruus

To ensure homogeneous conditions within the complete area of perfused microfluidic bio-reactors, we develop a general design of a continuously feed bio-reactor with uniform perfusion flow. This is achieved by introducing a specific type of perfusion inlet to the reaction area. The geometry of these inlets are found using the methods of topology optimization

A. Alapini, S. Aigrain

The detrending algorithms which are widely used to reduce the impact of stellar variability on space-based transit surveys are ill-suited for estimating the parameters of confirmed planets, as they unavoidably alter the transit signal. We present a post-detection detrending algorithm, which filters out signal on other timescales than the period of the transi

Błażej Ruszczycki, Zhenyuan Zhao, Neil F. Johnson

We analyze the synchronous firings of the salamander ganglion cells from the perspective of the complex network viewpoint where the network&#39;s links reflect the correlated behavior of firings. We study the time-aggregated properties of the resulting network focusing on its topological features. The behavior of pairwise correlations has been inspected in o

M. Joyce, B. Marcos, F. Sylos Labini

Purely self-gravitating systems of point particles have been extensively studied in astrophysics and cosmology, mainly through numerical simulations, but understanding of their dynamics still remains extremely limited. We describe here results of a detailed study of a simple class of cold quasi-uniform initial conditions, for both finite open systems and inf

Vlatko Vedral

We show that if the ground state entanglement exceeds the total entropy of a given system, then this system is in an entangled state. This is a universal entanglement witness that applies to any physical system and yields a temperature below which we are certain to find some entanglement. Our witness is then applied to generic bosonic and fermionic many body

Anand D. Joshi, Nandita Srivastava, Shibu K. Mathew

A new algorithm is developed that automatically detects filaments on the solar disc in H-alpha images. Preprocessing of H-alpha images include corrections for limb darkening and foreshortening. Further, by applying suitable intensity and size thresholds, filaments are extracted, while other solar features e.g. sunspots and plages are removed. Filaments attri

M. S. Westmoquette, K. M. Exter, L. Christensen, M. Maier

In this article we present the integral field spectroscopy (IFS) wiki site, http://ifs.wikidot.com; what the wiki is, our motivation for creating it, and a short introduction to IFS. The IFS wiki is designed to be a central repository of information, tips, codes, tools, references, etc., regarding the whole subject of IFS, which is accessible and editable by

Cenalo Vaz

The existence of a thermodynamic description of horizons indicates that spacetime has a microstructure. While the &#34;fundamental&#34; degrees of freedom remain elusive, quantizing Einstein&#39;s gravity provides some clues about their properties. A quantum AdS black hole possesses an equispaced mass spectrum, independent of Newton&#39;s constant, $G$, when

K. J. Falconer, A. Samuel

We show how multifractal properties of a measure supported by a fractal F contained in [0,1] may be expressed in terms of complementary intervals of F and thus in terms of spectral triples and the Dixmier trace of certain operators. For self-similar measures this leads to a noncommutative integral over $F$ equivalent to integration with respect to an auxilar

D. Moroni-Klementowicz, M. Brando, C. Albrecht, W. J. Duncan

We present a systematic study of transport and thermodynamic properties of the Laves phase system Nb$_{1-y}$Fe$_{2+y}$. Our measurements confirm that Fe-rich samples, as well as those rich in Nb (for $\mid y\mid\geq 0.02$), show bulk ferromagnetism at low temperature. For stoichiometric NbFe$_2$, on the other hand, magnetization, magnetic susceptibility and

Anwar Al Hamra, Nikitas Liogkas, Arnaud Legout, Chadi Barakat

Swarming peer-to-peer systems play an increasingly instrumental role in Internet content distribution. It is therefore important to better understand how these systems behave in practice. Recent research efforts have looked at various protocol parameters and have measured how they affect system performance and robustness. However, the importance of the strat

K. Pachucki, V. A. Yerokhin

In order to explain discrepancies between theoretical predictions and experimental data for the helium fine structure, we check and recalculate all theoretical contributions up to orders mα^7 and m^2/Mα^6. The previous result for the mα^7 correction is improved by a much more accurate calculation of relativistic corrections to the Bethe logarithm. The theore

I. Serban, F. K. Wilhelm

We provide insight into the qubit measurement process involving a switching type of detector. We study the switching-induced decoherence during escape events. We present a simple method to obtain analytical results for the qubit dephasing and bit-flip errors, which can be easily adapted to various systems. Within this frame we investigate potential of switch

Javier Rico, Robert Wagner

MAGIC is a single-dish Cherenkov telescope located on La Palma (Spain), hence with an optimal view on the Northern sky. Sensitive in the 30 GeV-30 TeV energy band, it is nowadays the only ground-based instrument being able to measure high-energy gamma-rays below 100 GeV. We review the most recent experimental results obtained using MAGIC.

Xianshi Lin, Xuguang Huang

In this paper, tooth-shaped and multiple-teeth-shaped plasmonic filters in the metal-insulator-metal (MIM) waveguides are demonstrated numerically. By introducing a three-port waveguide splitter, a modified model based on the multiple-beam-interference and the scattering matrix is given. The ransmittance spectrum as a function of teeth width, depth, period a

V. I. Anisimov, E. Z. Kurmaev, A. Moewes, I. A. Izyumov

LDA+DMFT (Local Density Approximation combined with Dynamical Mean-Field Theory) computation scheme has been used to calculate spectral properties of LaFeAsO -- the parent compound of the new high-T_c iron oxypnictides. The average Coulomb repulsion U=3-4 eV and Hund&#39;s exchange J=0.8 eV parameters for iron 3d electrons were calculated using the first pri

Anand D. Joshi, Shibu K. Mathew, Nandita Srivastava, Sara F. Martin

A new instrument with a dual-beam H-alpha Doppler system is being developed at the Udaipur Solar Observatory (USO) in order to improve the quality and quantity of data on quiet, activated and erupting filaments and prominences on the Sun, especially those associated with geo-effective coronal mass ejections. These data can be potentially used to construct th

S. J. Dilworth, E. Odell, Th. Schlumprecht, A. Zsak

We consider the $X$-Greedy Algorithm and the Dual Greedy Algorithm in a finite-dimensional Banach space with a strictly monotone basis as the dictionary. We show that when the dictionary is an initial segment of the Haar basis in $L_p[0,1]$ ($1 < p < \infty$) then the algorithms terminate after finitely many iterations and that the number of iterations is bo

Jing-Min Hou

We investigate the spectrum and eigenstates of ultracold fermionic atoms in the bilayer honeycomb optical lattice. In the low energy approximation, the dispersion relation has parabolic form and the quasiparticles are chiral. In the presence of the effective magnetic field, which is created for the system with optical means, the energy spectrum shows an unco