December 2008 arXiv papers — page 28

Weiwei Lin, Hai Sang

It is found in the Pt/Co/Pt(111) sandwiches that perpendicular magnetic anisotropy weakens associated with the dramatic magnetization enhancement as the temperature decreases below a critical temperature, T_cri, which increases with the Pt overlayer thickness t_Pt. For the sandwich with enough thick Pt overlayer, it trends to an unusual state with weak perpe

D. Manreza Paret, A. Perez Martinez, A. Ulacia Rey, Roberto A. Sussman

We examine the dynamics of a self--gravitating magnetized neutron gas as a source of a Bianchi I spacetime described by the Kasner metric. The set of Einstein-Maxwell field equations can be expressed as a dynamical system in a 4-dimensional phase space. Numerical solutions of this system reveal the emergence of a point--like singularity as the final evolutio

Loïc Chaumont, Andreas Kyprianou, Juan Carlos Pardo, Víctor Rivero

For a positive self-similar Markov process, X, we construct a local time for the random set, $Θ$, of times where the process reaches its past supremum. Using this local time we describe an exit system for the excursions of X out of its past supremum. Next, we define and study the ladder process (R,H) associated to a positive self-similar Markov process X, na

Thomas Michael Keller

In his paper "Finite groups have many conjugacy classes" (J. London Math. Soc (2) 46 (1992), 239-249), L. Pyber proved the to date best general lower bounds for the number of conjugacy classes of a finite group in terms of the order of the group. In this paper we strengthen the main results in Pyber's paper.

Philip T. Gressman

In the combinatorial method proving of $L^p$-improving estimates for averages along curves pioneered by Christ (IMRN, 1998), it is desirable to estimate the average modulus (with respect to some uniform measure on a set) of a polynomial-like function from below using only the value of the function or its derivatives at some prescribed point. In this paper, i

Anna Cima, Armengol Gasull, Victor Manosa

Given two ellipses, one surrounding the other one, Poncelet introduced a map $P$ from the exterior one to itself by using the tangent lines to the interior ellipse. This procedure can be extended to any two smooth, nested and convex ovals and we call this type of maps Poncelet's maps. We recall what he proved around 1814 in the dynamical systems language

Octavio R. Salmon, Nuno Crokidakis, Fernando D. Nobre

A random-field Ising model that is capable of exhibiting a rich variety of multicritical phenomena, as well as a smearing of such behavior, is investigated. The model consists of an infinite-range-interaction Ising ferromagnet in the presence of a triple-Gaussian random magnetic field, which is defined as a superposition of three Gaussian distributions with

Shea Brown, Lawrence Rudnick, Damon Farnsworth

We present our attempts to detect magnetic fields in filamentary large-scale structure (LSS) by observing polarized synchrotron emission emitted by structure formation shocks. Little is known about the strength and order of magnetic fields beyond the largest clusters of galaxies, and synchrotron emission holds enormous promise as a means of probing magnetic

William Detmold, C. -J. David Lin, Matthew Wingate

Dynamical 2+1 flavour lattice QCD is used to calculate the splittings between the masses of mesons and baryons containing a single static heavy quark and domain-wall light and strange quarks. Our calculations are based on the dynamical domain-wall gauge field configurations generated by the RBC and UKQCD collaborations at a spatial volume of (2.7 fm)^3 and a

Sofia Wechsler

Hardy's thought-experiment is the strongest argument against the idea of continuous trajectories of particles from the source to the detector. This idea seems to result as an unavoidable conclusion from some simple experiments. In its original form, Hardy's thought-experiment was proposed for two independent particles, a positron and an electron. The

Massimo Tinto, George J. Dick, John D. Prestage, J. W. Armstrong

Recent advances in space-qualified atomic clocks (low-mass, low power-consumption, frequency stability comparable to that of ground-based clocks) can enable interplanetary spacecraft radio science experiments at unprecedented Doppler sensitivities. The addition of an on-board digital receiver would allow the up- and down-link Doppler frequencies to be measur

Kay Potzger, Shengqiang Zhou, Qingyu Xu, Artem Shalimov

We present superparamagnetic clusters of structurally highly disordered Co-Zn-O created by high fluence Co ion implantation into ZnO (0001) single crystals at low temperatures. This secondary phase cannot be detected by common x-ray diffraction but is observed by high-resolution transmission electron microscopy. In contrast to many other secondary phases in

Seyyed Majid Valiollahzadeh, Abolghasem Sayadiyan, Mohammad Nazari

Recently, Adaboost has been widely used to improve the accuracy of any given learning algorithm. In this paper we focus on designing an algorithm to employ combination of Adaboost with Support Vector Machine as weak component classifiers to be used in Face Detection Task. To obtain a set of effective SVM-weaklearner Classifier, this algorithm adaptively adju

Seyyed Majid Valiollahzadeh, Abolghasem Sayadiyan, Mohammad Nazari

Applications such as face recognition that deal with high-dimensional data need a mapping technique that introduces representation of low-dimensional features with enhanced discriminatory power and a proper classifier, able to classify those complex features. Most of traditional Linear Discriminant Analysis suffer from the disadvantage that their optimality

Joachim Hilgert

Robbin and Salamon showed that attractor-repellor networks and Lyapunov maps are equivalent concepts and illustrate this with the example of linear flows on projective spaces. In these examples the fixed points are linearly ordered with respect to the Smale order which makes the attractor-repellor network overly simple. In this paper we provide a class of ex

Ion Garate, K. Gilmore, M. D. Stiles, A. H. MacDonald

The motion of simple domain walls and of more complex magnetic textures in the presence of a transport current is described by the Landau-Lifshitz-Slonczewski (LLS) equations. Predictions of the LLS equations depend sensitively on the ratio between the dimensionless material parameter $β$ which characterizes non-adiabatic spin-transfer torques and the Gilber

Tatsuru Kikuchi

We extend a model of the Dirac gauginos, which originate from N=2 supersymmetry (SUSY) for the gauge sector, such that the N=2 SUSY is imposed also to the sfermion sector but only for the 3rd generation squarks and sleptons. In addition to the N=2 supersymmetry, our model is constructed based on the SU(3)c times SU(3)L times U(1)' gauge symmetry. By this

James M. Stone, Daniel Proga

We present two-dimensional hydrodynamic models of thermally driven winds from highly irradiated, close-in extra-solar planets. We adopt a very simple treatment of the radiative heating processes at the base of the wind, and instead focus on the differences between the properties of outflows in multidimensions in comparison to spherically symmetric models com

Jian Li

In this paper, we consider the Shapley network design game on undirected networks. In this game, we have an edge weighted undirected network $G(V,E)$ and $n$ selfish players where player $i$ wants to choose a path from source vertex $s_i$ to destination vertex $t_i$. The cost of each edge is equally split among players who pass it. The price of stability is

Driss Bennis, Najib Mahdou

This paper generalize the idea of the authors in J. Pure Appl. Algebra 210 (2007) 437--445. Namely, we define and study a particular case of Gorenstein projective modules. We investigate some change of rings results for this new kind of modules. Examples over not necessarily Noetherian rings are given.

A. Shahbaz, C. Müller, T. J. Buervenich, C. H. Keitel

Coherent nuclear excitation in strongly laser-driven muonic atoms is calculated. The nuclear transition is caused by the time-dependent Coulomb field of the oscillating charge density of the bound muon. A closed-form analytical expression for electric multipole transitions is derived and applied to various isotopes; the excitation probabilities are in genera

C. Englert, B. Jager, D. Zeppenfeld

We discuss the signatures of a representative Higgsless model with ideal fermion delocalization in vector-boson fusion processes, focusing on the gold- and silver-plated decay modes of the gauge bosons at the CERN-Large Hadron Collider. For this purpose, we have developed a fully-flexible parton-level Monte-Carlo program, which allows for the calculation of

Sergio Amat, Karine Dadourian, Jacques Liandrat

This paper is devoted to the presentation and the analysis of a new nonlinear subdivision scheme eliminating the Gibbs oscillations close to discontinuities. Its convergence, stability and order of approximation are analyzed. It is proved that this schemes converges towards limit functions of Hölder regularity index larger than 1.192. Numerical estimates pro

M. Mugrauer, R. Neuhaeuser

Aims: We present new results from our ongoing multiplicity study of exoplanet host stars, carried out with SofI/NTT. We provide the most recent list of confirmed binary and triple star systems that harbor exoplanets. Methods: We use direct imaging to identify wide stellar and substellar companions as co-moving objects to the observed exoplanet host stars, wh

Akin Tanatmis, Stefan Ruzika, Horst W. Hamacher, Mayur Punekar

Maximum Likelihood (ML) decoding is the optimal decoding algorithm for arbitrary linear block codes and can be written as an Integer Programming (IP) problem. Feldman et al. relaxed this IP problem and presented Linear Programming (LP) based decoding algorithm for linear block codes. In this paper, we propose a new IP formulation of the ML decoding problem a

Colin Adams, Reiko Shinjo, Kokoro Tanaka

An increasing sequence of integers is said to be universal for knots and links if every knot and link has a projection to the sphere such that the number of edges of each complementary face of the projection comes from the given sequence. This paper is an investigation into which sequences, either finite or infinite, are universal. We also consider how to mi

Kai Grass, Christian Holm

We use a coarse-grained molecular dynamics model to study the electrophoretic behaviour of flexible polyelectrolyte chains. We first characterize the static properties of the model with respect to the chain length, the polyelectrolyte concentration, additional salt and the influence of an applied external field. Next we investigate the dynamic behaviour in t

Daniel M. Kaplan

Fermilab operates the world's most intense source of antiprotons. Recently various experiments have been proposed that can use those antiprotons either parasitically during Tevatron Collider running or after the Tevatron Collider finishes in about 2010. We discuss the physics goals and prospects of the proposed experiments.

Y. Safarov

The aim of the paper is to show that L. Friedlander's results on the relation between Dirichlet and Neumann counting functions (Arch. Ration. Mech. Anal. 116, 1991) remain valid in abstract setting.

Taekyun Kim

In this paper we consider Dedekind type DC sums and prove receprocity laws related to DC sums.

James Springham, Stephen Wiggins

We prove that a Lebesgue measure-preserving linked-twist map defined in the plane is metrically isomorphic to a Bernoulli shift (and thus strongly mixing). This is the first such result for an explicitly defined linked-twist map on a manifold other than the two-torus. Our work builds on that of Wojtkowski who established an ergodic partition for this example

G. Hector, E. Macías-Virgós, A. Sotelo-Armesto

We explicitly compute the diffeomorphism group of several types of linear foliations (with dense leaves) on the torus $T^n$, $n\geq 2$, namely codimension one foliations, flows, and the so-called non-quadratic foliations. We show in particular that non-quadratic foliations are rigid, in the sense that they do not admit transverse diffeomorphisms other than $

Vladislav V. Goldberg, Valentin V. Lychagin

We present a complete description of a class of linearizable planar geodesic webs which contain a parallelizable 3-subweb.

Yousra Chabchoub, Christine Fricker, Fabrice Guillemin, Philippe Robert

We show in this note that by deterministic packet sampling, the tail of the distribution of the original flow size can be obtained by rescaling that of the sampled flow size. To recover information on the flow size distribution lost through packet sampling, we propose some heuristics based on measurements from different backbone IP networks. These heuristic

Christine Fricker, Fabrice Guillemin, Philippe Robert

We study in this paper an $M/M/1$ queue whose server rate depends upon the state of an independent Ornstein-Uhlenbeck diffusion process $(X(t))$ so that its value at time $t$ is $μϕ(X(t))$, where $ϕ(x)$ is some bounded function and $μ>0$. We first establish the differential system for the conditional probability density functions of the couple $(L(t),X(t))$

Dragoljub A. Cucic

Paradoxes are a very frequent phenomenon in processes of thought which strive towards the intelectual and cognitive shifts. They occur in all areas of human spiritual activites. What we are interested here in, are the paradoxes in physics. We will try to give the answers to the questions such as: What are the reasons for developing the paradox in physics? Ca

M. I. Vysotsky

General formulas as well as leading asymptotics for corrections to Z- and W-boson parameters are derived. Experimental data fits in Standard Model and its extensions are discussed and results are presented.

Dragoljub A. Cucic

Thought experiment is an apparition in a modern Science, which is in last 100 Years took sweep. Work is based at the aspect of Physics, because and the writer is from Physics. Manners to study thought experiments are multiple, and this work is only one aspect in that complex of feasibility. About real character of thought experiment will be made conclusion w

V. F. Dmitriev

Using a simple phenomenological parametrization of the reaction amplitude we calculated $α$-particle spectrum in the reaction p+$^{11}$B$\to α+ ^8Be^*\to 3α$ at the resonance proton energy 675 KeV. The parametrization includes Breit-Wigner factor with an energy dependent width for intermediate $^8Be^*$ state and the Coulomb and the centrifugal factors in $α$

Takumi Muto, Toshiki Maruyama, Toshitaka Tatsumi

Properties of multi-antikaonic nuclei (MKN), where several numbers of $K^-$ mesons are bound, are studied in the relativistic mean-field model, combined with chiral dynamics for kaonic part of the thermodynamic potential. The density profiles for nucleons and $K^-$ mesons, the single particle energy of the $K^-$ mesons, and binding energy of the MKN are obta

Dasika Ratna Deepthi, K. Eswaran

In this paper, we present a new kind of learning implementation to recognize the patterns using the concept of Mirroring Neural Network (MNN) which can extract information from distinct sensory input patterns and perform pattern recognition tasks. It is also capable of being used as an advanced associative memory wherein image data is associated with voice i

Sean A. Hayward, R. Di Criscienzo, M. Nadalini, L. Vanzo

A local Hawking temperature was recently derived for any future outer trapping horizon in spherical symmetry, using a Hamilton-Jacobi tunneling method, and is given by a dynamical surface gravity as defined geometrically. Descriptions are given of the operational meaning of the temperature, in terms of what observers measure, and its relation to the usual Ha

Pierre Kervella, Armando Domiciano De Souza, Samer Kanaan, Anthony Meilland

Context: As is the case of several other Be stars, Achernar is surrounded by an envelope, recently detected by near-IR interferometry. Aims: We search for the signature of circumstellar emission at distances of a few stellar radii from Achernar, in the thermal IR domain. Methods: We obtained interferometric observations on three VLTI baselines in the N band

Y. Yamato, M. Matsukawa, R. Suryanarayanan, S. Nimori

We report a significant decrease in the low-temperature resistance induced by the application of an electric current on the $ab$-plane in the paramagnetic insulating (PMI) state of (La$_{0.4}$Pr$_{0.6}$)$_{1.2}$Sr$_{1.8}$Mn$_{2}$O$_{7}$. A colossal electroresistance effect attaining -95% is observed at lower temperatures. A colossal magnetoresistive step app

Sophie Laplace, Marc Dalmau, Philippe Roose

One of the current challenges of Information Systems is to ensure semi-structured data transmission, such as multimedia data, in a distributed and pervasive environment. Information Sytems must then guarantee users a quality of service ensuring data accessibility whatever the hardware and network conditions may be. They must also guarantee information cohere

Desheng Kong, Siming Wang, Chinping Chen

The magnetization ground states (MGSs) for a nanosized Co hollow sphere, with the outer radius, R < 50 nm, have been studied numerically by micromagnetic simulation using object oriented micromagnetic framework (OOMMF). In addition to the originally known single domain and vortex-curling states, a three dimensional &#34;onion&#34; state with a corresponding

Sachiko Takeuchi, Kiyotaka Shimizu

We investigate Lambda(1405) as a resonance in a coupled channel baryon-meson scattering with a `bound state embedded in the continuum&#39;(BSEC). This BSEC is introduced by hand, as a state not originated from simple baryon-meson systems. We assume it comes from the three-quark state. There appears a resonance in the Sigma pi scattering below the N Kbar thre

Malcolm Anderson

A solution of the linearized Einstein and Nambu-Goto equations is constructed which describes the evaporation of a certain type of rotating cosmic string - the Allen-Casper-Ottewill loop - under the action of its own self-gravity. The solution evaporates self-similarly, and radiates away all its mass-energy and momentum in a finite time. Furthermore, the cor

Yahya Ould Hamidoune

A {\em Wakeford pairing} from $S$ onto $T$ is a bijection $ϕ: S \to T$ such that $xϕ(x)\notin T,$ for every $x\in S.$ The number of such pairings will be denoted by $μ(S,T)$. Let $A$ and $ B$ be finite subsets of a group $G$ with $1\notin B$ and $|A|=|B|.$ Also assume that the order of every element of $B$ is $\ge |B|$. Extending results due to Losonczy and

Fethi M Ramazanoglu

We provide an explicit analytical calculation that shows the asymptotic approach of the one dimensional Caldeira-Leggett model to thermal equilibrium in the high temperature and weak coupling limit. We investigate a free particle and a harmonic oscillator system, using both the Lindblad and the non-Lindblad type master equations for each case, and show that

Zhifang Zhang, Mulan Liu, Yeow Meng Chee, San Ling

Strongly multiplicative linear secret sharing schemes (LSSS) have been a powerful tool for constructing secure multiparty computation protocols. However, it remains open whether or not there exist efficient constructions of strongly multiplicative LSSS from general LSSS. In this paper, we propose the new concept of a 3-multiplicative LSSS, and establish its

Milos Milosavljevic, Sean M. Couch, Volker Bromm

We present the first results from two-dimensional simulations of radiatively-efficient accretion of metal-free gas onto intermediate-mass black holes. We fix the shape of the spectral energy distribution of the radiation produced near the event horizon and study the structure of the irradiated low-angular-momentum accretion flow over three orders of magnitud

Greg Salvesen, John C. Raymond, Richard J. Edgar

Upper limits on the shock speeds in supernova remnants can be combined with post-shock temperatures to obtain upper limits on the ratio of cosmic ray to gas pressure (P_CR / P_G) behind the shocks. We constrain shock speeds from proper motions and distance estimates, and we derive temperatures from X-ray spectra. The shock waves are observed as faint H-alpha

Konstantin Goulianos

Results on diffraction from the Fermilab Tevatron collider obtained by the CDF II Collaboration using data from proton-antiproton collisions at a c.m.s. energy of 1.96 TeV are reviewed and compared with theoretical expectations. Implications for predictions of exclusive Higgs boson production rates at the Large Hadron Collider are discussed.

O. Wessely, B. Skubic, L. Nordstrom

The current driven magnetisation dynamics of a helical spin-density wave is investigated. Expressions for calculating the spin-transfer torque of real systems from first principles density functional theory are presented. These expressions are used for calculating the spin-transfer torque for the spin spirals of Er and fcc Fe at two different lattice volumes

Jin-Qiang Zhong, Denis Funfschilling, Guenter Ahlers

We report measurements of turbulent heat-transport in samples of ethane (C$_2$H$_6$) heated from below while the applied temperature difference $ΔT$ straddled the liquid-vapor co-existance curve $T_ϕ(P)$. When the sample top temperature $T_t$ decreased below $T_ϕ$, droplet condensation occurred and the latent heat of vaporization $H$ provided an additional h

Enrique Gaztanaga, Anna Cabre

In a series of papers we have recently studied the clustering of LRG galaxies in the latest spectroscopic SDSS data release, which has 75000 LRG galaxies sampling 1.1 Gpc^3/h^3 to z=0.47. Here we focus on detecting a local maxima shaped as a circular ring in the bidimensional galaxy correlation function ξ(pi,sigma), separated in perpendicular σand line-of-si

P. G. Grinevich, K. V. Kaipa

The most basic characteristic of x-quasiperiodic solutions u(x,t) of the sine-Gordon equation u_{tt}-u_{xx}+\sin u=0 is the topological charge density denoted $\bar n$. The real finite-gap solutions u(x,t) are expressed in terms of the Riemann theta-functions of a non-singular hyperelliptic curve $Γ$ and a positive generic divisor D of degree g on $Γ$, where

Tal Poznansky

The reduced C*-algebra of a countable linear group G is shown to be simple if and only if G has no nontrivial normal amenable subgroups. Moreover, these conditions are shown to be equivalent to the uniqueness of tracial state on the aforementioned C*-algebra.

M. D. Shaw, J. F. Schneiderman, J. Bueno, B. S. Palmer

We characterize a pair of Cooper-pair boxes coupled with a fixed capacitor using spectroscopy and measurements of the ground-state quantum capacitance. We use the extracted parameters to estimate the concurrence, or degree of entanglement between the two qubits. We also present a thorough demonstration of a multiplexed quantum capacitance measurement techniq

Shen Jun, Wu Junde

Let $E$ be an effect algebra and $E_S$ be the set of all sharp elements of $E$. $E$ is said to be sharply dominating if for each $a\in E$ there exists a smallest element $\widehat{a}\in E_s$ such that $a\leq \widehat{a}$. In 2002, Professors Gudder and Greechie proved that each $σ$-sequential effect algebra is sharply dominating. In 2005, Professor Gudder pr

G. G. Howes, S. C. Cowley, W. Dorland, G. W. Hammett

Howes et al. Reply to Comment on "Kinetic Simulations of Magnetized Turbulence in Astrophysical Plasmas" arXiv:0711.4355

Luca Fabbri, M. B. Paranjape

We consider plane-fronted, monochromatic gravitational waves on a Minkowski background, in a conformally invariant theory of general relativity. By this we mean waves of the form: $g_{μν}=η_{μν}+ε_{μν}F(k\cdotx)$, where $ε_{μν}$ is a constant polarization tensor, and $k_μ$ is a lightlike vector. We also assume the coordinate gauge condition $|g|-1/4\partial_

R. L. C. Starling, E. Rol, A. J. van der Horst, S. -C. Yoon

We follow the bright, highly energetic afterglow of Swift-discovered GRB 080721 at z=2.591 out to 36 days or 3e6 s since the trigger in the optical and X-ray bands. We do not detect a break in the late-time light curve inferring a limit on the opening angle of theta_j >= 7.3 deg and setting tight constraints on the total energy budget of the burst of E_gamma

Kenji Toma, Takanori Sakamoto, Bing Zhang, Joanne E. Hill

The emission mechanism and the origin and structure of magnetic fields in gamma-ray burst (GRB) jets are among the most important open questions concerning the nature of the central engine of GRBs. In spite of extensive observational efforts, these questions remain to be answered and are difficult or even impossible to infer with the spectral and lightcurve

M. E. Putman, J. E. G. Peek, A. Muratov, O. Y. Gnedin

The disruption of the M33 galaxy is evident from its extended gaseous structure. We present new data from the Galactic Arecibo L-Band Feed Array HI (GALFA-HI) Survey that show the full extent and detailed spatial and kinematic structure of M33&#39;s neutral hydrogen. Over 18% of the HI mass of M33 (M_HI(tot) =1.4 x 10^9 Msun) is found beyond the star forming

T. Heinemann, J. C. B. Papaloizou

We present fully three-dimensional local MRI simulations with the object of studying the excitation of non-axisymmetric spiral density waves that are observed to always be present in such simulations. They are potentially important for affecting protoplanetary migration through the action of associated stochastic gravitational forces and producing residual t

M. Razavi, I. Söllner, E. Bocquillon, C. Couteau

Any characterization of a single-photon source is not complete without specifying its second-order degree of coherence, i.e., its $g^{(2)}$ function. An accurate measurement of such coherence functions commonly requires high-precision single-photon detectors, in whose absence, only time-averaged measurements are possible. It is not clear, however, how the re

Krzysztof Belczynski, Daniel E. Holz, Chris L. Fryer, Edo Berger

GRB 080913 and GRB 090423 are the most distant gamma-ray bursts (GRBs) known to-date, with spectroscopically determined redshifts of z=6.7 and z=8.1, respectively. The detection of bursts at this early epoch of the Universe significantly constrains the nature of GRBs and their progenitors. We perform population synthesis studies of the formation and evolutio

H. Hafermann, G. Li, A. N. Rubtsov, M. I. Katsnelson

We present a novel approach to long-range correlations beyond dynamical mean-field theory through a ladder approximation to dual fermions. The new technique is applied to the two-dimensional Hubbard model. We demonstrate that the transformed perturbation series for the nonlocal dual fermions has superior convergence properties over standard diagrammatic tech

L. Qian, M. A. Abramowicz, P. C. Fragile, J. Horak

We construct a new family of analytic models of black hole accretion disks in dynamical equilibria. Our construction is based on assuming distributions of angular momentum and entropy. For a particular choice of the distribution of angular momentum, we calculate the shapes of equipressure surfaces. The equipressure surfaces we find are similar to those in th

Yu-Hin Au, Aaron Robertson, Jeffrey Shallit

Pirillo and Varricchio, and independently, Halbeisen and Hungerbuhler considered the following problem, open since 1994: Does there exist an infinite word w over a finite subset of Z such that w contains no two consecutive blocks of the same length and sum? We consider some variations on this problem in the light of van der Waerden&#39;s theorem on arithmeti

V. Petit, A. W. Fullerton, S. Bagnulo, G. A. Wade

Oe stars are a subset of the O-type stars that exhibit emission lines from a circumstellar disk. The recent detection of magnetic fields in some O-type stars suggests a possible explanation for the stability of disk-like structures around Oe stars. According to this hypothesis, the wind of the star is channeled by a dipolar magnetic field producing a disc in

Niayesh Afshordi, Ghazal Geshnizjani, Justin Khoury

We present a case that current observations may already indicate new gravitational physics on cosmological scales. The excess of power seen in the Lyman-alpha forest and small-scale CMB experiments, the anomalously large bulk flows seen both in peculiar velocity surveys and in kinetic SZ, and the higher ISW cross-correlation all indicate that structure may b

Augustin Banyaga, Peter Spaeth

We prove that for regular contact forms there exists a bijective correspondence between the $C^0$ limits of sequences of smooth strictly contact isotopies and the limits with respect to the contact distance of their corresponding Hamiltonians.

Qi S. Zhang

We establish certain Gaussian type upper bound for the heat kernel of the conjugate heat equation associated with 3 dimensional ancient $κ$ solutions to the Ricci flow. As an application, using the $W$ entropy associated with the heat kernel, we give a different and shorter proof of Perelman&#39;s classification of backward limits of these ancient solutions.

A. C. Lehum

The dynamical breaking of gauge symmetry in the supersymmetric quantum electrodynamics in three-dimensional spacetime is studied at two-loop approximation. At this level, the effective superpotential is evaluated in a supersymmetric phase. At one-loop order, we observe a generation of the Chern-Simons term due to a parity violating term present in the classi

Annamaria Montanari, Daniele Morbidelli

We prove a ball-box theorem for nonsmooth Hormander vector fields of step s.

B. Venhlovska, B. Novosyadlyj

The power spectrum of number density perturbations of free electrons is obtained for the epoch of cosmological recombination of hydrogen. It is shown that amplitude of the electron perturbations power spectrum of scales larger than acoustic horizon exceeds by factor of 17 the amplitude of baryon matter density ones (atoms and ions of hydrogen and helium). In

Alain Bruguières, Alexis Virelizier

The center Z(C) of an autonomous category C is monadic over C (if certain coends exist in C). The notion of Hopf monad naturally arises if one tries to reconstruct the structure of Z(C) in terms of its monad Z: we show that Z is a quasitriangular Hopf monad on C and Z(C) is isomorphic to the braided category Z-C of Z-modules. More generally, let T be a Hopf

Anthony C. L Ashton, A. S. Fokas

The classical equations of irrotational water waves have recently been reformulated as a system of two equations, one of which is an explicit non-local equation for the wave height and for the velocity potential evaluated on the free surface. Here, in the two dimensional case, (a) we generalise the relevant formulation to the case of constant vorticity, as w

Miguel-Angel Sanchis-Lozano

Most signatures of new physics have been studied on the transverse plane with respect to the beam direction at the LHC where background is much reduced. In this paper we propose the analysis of inclusive longitudinal (pseudo)rapidity correlations among final-state (charged) particles in order to search for (un)particles belonging to a Hidden Sector beyond th

Alexandre F. Roch

We extend a linear version of the liquidity risk model of Cetin et al. (2004) to allow for price impacts. We show that the impact of a market order on prices depends on the size of the transaction and the level of liquidity. We obtain a simple characterization of self-financing trading strategies and a sufficient condition for no arbitrage. We consider a sto

Robert W. Johnson

The continuous wavelet transform may be enhanced by deconvolution with the wavelet response function. After correcting for the cone-of-influence, the power spectral density of the solar magnetic record as given by the derectified yearly sunspot number is calculated, revealing a spectrum of odd harmonics of the fundamental Hale cycle, and the integrated insta

Ignat Fialkovsky, Yuriy Pis&#39;mak, Vladimir Markov

We comment on a recent publication [1] by Fosco, Lombardo and Mazzitelli on Casimir energies for material slabs (`finite width mirrors&#39;) and report a discrepancy between results obtained there for a single mirror and some previous calculations. We provide a simple consistency check which proves that the method used in [1] is not reliable when applied to

S. Kimura, A. Anzalone, A. Bonasera

The paper by Belyaev et al. [Phys. Rev. E {\bf 72}, 026406 (2005)] reported the first experimental observation of alpha particles produced in the thermonuclear reaction $^{11}$B($p,α$)$^{8}$Be induced by laser-irradiation on a $^{11}$B polyethylene (CH$_2$) composite target. The laser used in the experiment is characterized by a picosecond pulse duration and

Roman Vershynin

We study the spectral norm of matrices M that can be factored as M=BA, where A is a random matrix with independent mean zero entries, and B is a fixed matrix. Under the (4+epsilon)-th moment assumption on the entries of A, we show that the spectral norm of such an m by n matrix M is bounded by \sqrt{m} + \sqrt{n}, which is sharp. In other words, in regard to

R. Ishizeki, M. Kruczenski, A. Tirziu, A. A. Tseytlin

We study a class of classical solutions for closed strings moving in AdS_3 x S^1 part of AdS_5 x S^5 with energy E and spin S in AdS_3 and angular momentum J and winding m in S^1. They have rigid shape with n spikes in AdS_3. We find that when J or m are non-zero, the spikes do not end in cusps. We consider in detail a special large n limit in which S ~ n^2,

Benedikt Bollig

Visibly pushdown automata are input-driven pushdown automata that recognize some non-regular context-free languages while preserving the nice closure and decidability properties of finite automata. Visibly pushdown automata with multiple stacks have been considered recently by La Torre, Madhusudan, and Parlato, who exploit the concept of visibility further t

Nasser Demir, Steffen A. Bass

Ultrarelativistic heavy-ion collisions at the Relativistic Heavy-Ion Collider (RHIC) are thought to have produced a state of matter called the Quark-Gluon-Plasma, characterized by a very small shear viscosity to entropy density ratio $η/s$, near the lower bound predicted for that quantity by Anti-deSitter space/Conformal Field Theory (AdS/CFT) methods. As th

M. G. Ryskin, A. D. Martin, V. A. Khoze

We emphasize the sizeable effects of absorption on high-energy `soft&#39; processes, and, hence, the necessity to include multi-Pomeron-Pomeron interactions in the usual multi-channel eikonal description. We present a model which includes a complete set of the multi-Pomeron vertices and which accounts for the diffusion in both, the impact parameter and ln(k_

Manuela Capello, Didier Poilblanc

Scanning tunneling microscopy (STM) by providing images of the effects of individual zinc-impurities in cuprate superconductors with unprecedented atomic-resolution offers a stringent test to models of correlated fermions for high-temperature superconductors. Using a t-J model supplemented by Variational Monte Carlo many-body techniques, the spatial dependen

Haitan Xu, Xin Wan

In a topological quantum computer, braids of non-Abelian anyons in a (2+1)-dimensional space-time form quantum gates, whose fault tolerance relies on the topological, rather than geometric, properties of the braids. Here we propose to create and exploit redundant geometric degrees of freedom to improve the theoretical accuracy of topological single- and two-

M. G. Ryskin, A. D. Martin, V. A. Khoze

We calculate the probability that the rapidity gaps in diffractive processes survive both eikonal and enhanced rescattering. We present arguments that enhanced rescattering, which violates soft-hard factorization, is not very strong. Accounting for NLO effects, there is no reason to expect that the black disc regime is reached at the LHC. We discuss the pred

Adam Pantanowitz, Tshilidzi Marwala

This paper presents an impact assessment for the imputation of missing data. The data set used is HIV Seroprevalence data from an antenatal clinic study survey performed in 2001. Data imputation is performed through five methods: Random Forests, Autoassociative Neural Networks with Genetic Algorithms, Autoassociative Neuro-Fuzzy configurations, and two Rando

Giulia Gualdi, Irene Marzoli, Paolo Tombesi

We propose to use ferromagnetic systems for entanglement generation and distribution together with perfect state transfer between distant parties in a qubit chain. The scheme relies on an effective 2-qubit dynamics, realized by leaving two empty sites in a uniformly filled chain. This allows long-range interacting qubit chains to serve as quantum channels fo

Marco Pizzi, Armando Paolino

We describe the equation of motion of two charged spherical shells with tangential pressure in the field of a central Reissner-Nordstrom (RN) source. We solve the problem of determining the motion of the two shells \textsl{after} the intersection by solving the related Einstein-Maxwell equations and by requiring a physical continuity condition on the shells

Fernando Marchesano, Paul McGuirk, Gary Shiu

We analyze the wavefunctions for open strings in warped compactifications, and compute the warped Kahler potential for the light modes of a probe D-brane. This analysis not only applies to the dynamics of D-branes in warped backgrounds, but also allows to deduce warping corrections to the closed string Kahler metrics via their couplings to open strings. We c

Koichi Hamaguchi, Satoshi Shirai, T. T. Yanagida

The anomalies observed in recent cosmic ray experiments seem to strongly constrain the nature of the dark matter. In this letter, we investigate a possibility of the fermionic dark matter with a minimal extension of the standard model. We found that the dark matter decays caused by the dimension six operators can naturally explain the anomalies.

András Bálint

For parameters $p\in[0,1]$ and $q>0$ such that the Fortuin--Kasteleyn (FK) random-cluster measure $Φ_{p,q}^{\mathbb{Z}^d}$ for $\mathbb{Z}^d$ with parameters $p$ and $q$ is unique, the $q$-divide and color [$\operatorname {DaC}(q)$] model on $\mathbb{Z}^d$ is defined as follows. First, we draw a bond configuration with distribution $Φ_{p,q}^{\mathbb{Z}^d}$.