September 2009 arXiv papers — page 52
Showing 5,101–5,200 of 5,691 papers
Ilka Brunner, Daniel Roggenkamp, Sebastiano Rossi
Perturbations of B-type defects in Landau-Ginzburg models are considered. In particular, the effect of perturbations of defects on their fusion is analyzed in the framework of matrix factorizations. As an application, it is discussed how fusion with perturbed defects induces perturbations on boundary conditions. It is shown that in some classes of models all
Bistability and oscillatory motion of natural nano-membranes appearing within monolayer graphene on silicon dioxide
cond-mat.mes-hallT. Mashoff, M. Pratzer, V. Geringer, T. J. Echtermeyer
The recently found material graphene is a truly two-dimensional crystal and exhibits, in addition, an extreme mechanical strength. This in combination with the high electron mobility favours graphene for electromechanical investigations down to the quantum limit. Here, we show that a monolayer of graphene on SiO2 provides natural, ultra-small membranes of di
J. R. Morris
A Kaluza-Klein model, with a matter source associated with Hawking radiation from an evaporating black hole, is used to obtain a simple form for the radion effective potential. The environmental effect generally causes a matter-induced shift of the radion vacuum, resulting in the formation of a radion cloud around the hole. There is an albedo due to the radi
H. Beuther, A. J. Walsh, S. N. Longmore
To better understand the physical properties of accretion disks in high-mass star formation, we present a study of a 12 high-mass accretion disk candidates observed at high spatial resolution with the Australia Telescope Compact Array (ATCA) in the NH3 (4,4) and (5,5) lines. Almost all sources were detected in NH3, directly associated with CH3OH Class II mas
Abundance Analysis of the Halo Giant HD122563 with Three-Dimensional Model Stellar Atmospheres
astro-ph.SRR. Collet, A. Nordlund, M. Asplund, W. Hayek
We present a preliminary local thermodynamic equilibrium (LTE) abundance analysis of the template halo red giant HD122563 based on a realistic, three-dimensional (3D), time-dependent, hydrodynamical model atmosphere of the very metal-poor star. We compare the results of the 3D analysis with the abundances derived by means of a standard LTE analysis based on
Laura Ingleby, Nuria Calvet, Edwin Bergin, Ashwin Yerasi
We analyze the far-ultraviolet (FUV) spectra of 33 classical T Tauri stars (CTTS), including 20 new spectra obtained with the Advanced Camera for Surveys Solar Blind Channel (ACS/SBC) on the Hubble Space Telescope. Of the sources, 28 are in the ~1 Myr old Taurus-Auriga complex or Orion Molecular Cloud, 4 in the 8-10 Myr old Orion OB1a complex and one, TW Hya
Valery B. Kokshenev
Despite the great success of the Huxley sliding filament model proposed half a century ago for actin-myosin linkages (cross-bridges), it fails to explain the force-velocity behavior of stretching skeletal muscles. Huxley's two-state kinetic equation for cross-bridge proportions is therefore reconsidered and a new solution to the problem of steady muscle
Joel W. Branch, Chris Giannella, Boleslaw Szymanski, Ran Wolff
To address the problem of unsupervised outlier detection in wireless sensor networks, we develop an approach that (1) is flexible with respect to the outlier definition, (2) computes the result in-network to reduce both bandwidth and energy usage,(3) only uses single hop communication thus permitting very simple node failure detection and message reliability
Shirin Sohrabi, Sheila A. McIlraith
In this paper, we address the problem of generating preferred plans by combining the procedural control knowledge specified by Hierarchical Task Networks (HTNs) with rich qualitative user preferences. The outcome of our work is a language for specifyin user preferences, tailored to HTN planning, together with a provably optimal preference-based planner, HTNP
Patrick Berghaus
Data from the IceCube detector in its 22-string configuration (IC22) were used to directly measure the atmospheric muon energy spectrum near the horizon. After passage through more than 10 km of ice, muon bundles from air showers are reduced to single muons, whose energy can be estimated from the total number of photons registered in the detector. The energy
Leonid Förster, Michał Karski, Jai-Min Choi, Andreas Steffen
We control the quantum mechanical motion of neutral atoms in an optical lattice by driving microwave transitions between spin states whose trapping potentials are spatially offset. Control of this offset with nanometer precision allows for adjustment of the coupling strength between different motional states, analogous to an adjustable effective Lamb-Dicke f
L. da Silva, C. A. O. Torres, R. de la Reza, G. R. Quast
Our study is a follow-up of the SACY project, an extended survey in the Southern Hemisphere targeted to search for young nearby associations. Nine associations have either been newly identified, or had their member list better defined. These associations, with ages between about 6 Myr and 70 Myr, form an excellent sample to study the Li depletion in the pre-
Maik Boltes, Herwig Zilken, Joerg Schumacher
We present a fluid dynamics video which illustrates the Lagrangian aspects of local heat transfer in turbulent Rayleigh-Benard convection. The data are obtained from a direct numerical simulation.
R. Gerritsma, G. Kirchmair, F. Zähringer, E. Solano
The Dirac equation is a cornerstone in the history of physics, merging successfully quantum mechanics with special relativity, providing a natural description of the electron spin and predicting the existence of anti-matter. Furthermore, it is able to reproduce accurately the spectrum of the hydrogen atom and its realm, relativistic quantum mechanics, is con
Virial relations for ultracold trapped Fermi gases with finite range interactions through the BCS-BEC crossover
cond-mat.quant-gasL. E. C. Rosales-Zarate R. Jauregui
We study the virial relations for ultracold trapped two component Fermi gases in the case of short finite range interactions. Numerical verifications for such relations are reported through the BCS-BEC crossover. As an intermediate step, it is necessary to evaluate the partial derivatives of the many body energy with respect to the inverse of the scattering
Jiangbo Zhou, Lixin Tian, Xinghua Fan
In this paper, two types of traveling wave solutions to the osmosis K(2, 2) equation are investigated. They are characterized by two parameters. The expresssions for the soliton and periodic wave solutions are obtained.
Yu. Eltsev, S. Lee, K. Nakao, S. Tajima
We report on study of the vortex liquid in Pb-doped Bi-2223 single crystal using the in-plane resistivity measurements as a function of temperature and magnetic field up to 6T applied perpendicular to CuO planes. Below Tc at the upper part of superconducting transition we found Arrhenius-like resistivity behavior. With further temperature decrease close to r
D. Fabjan, S. Borgani, L. Tornatore, A. Saro
We present a study of the effect of AGN feedback on metal enrichment and thermal properties of the intracluster medium (ICM) in hydrodynamical simulations. The cosmological simulations are performed for a set of clusters using a version of the TreePM-SPH Gadget code that follows chemo-dynamical evolution by accounting for metal enrichment by different stella
Daniel Hampf, Martin Tluczykont, Dieter Horns
The proposed SCORE detector consists of a large array of light collecting modules designed to sample the Cherenkov light front of extensive air showers in order to detect high energy gamma-rays. A large spacing of the detector stations makes it possible to cover a huge area with a reasonable effort, thus achieving a good sensitivity up to energies of about a
Felix Brümmer
Minicharged particles (MCPs) arise naturally in extensions of the Standard Model with hidden sector gauge groups. Many such extensions also contain magnetic monopoles. For models containing both monopoles and MCPs, we clarify the role of the Dirac charge quantization condition in restricting the possible charges. We also show that monopoles of the hidden sec
E. Rovilos, V. Burwitz, G. Szokoly, G. Hasinger
We used the large binocular camera (LBC) mounted on the large binocular telescope (LBT) to observe the Lockman Hole in the U, B, and V bands. Our observations cover an area of 925 sq.arcmin. We reached depths of 26.7, 26.3, and 26.3 mag(AB) in the three bands, respectively, in terms of 50% source detection efficiency, making this survey the deepest U-band su
Fatemeh Dini, Reza Baghdadi, Reza Amrollahi, Sina Khorasani
This overview presents a tutorial introduction to the theory of magnetic plasma confinement in toroidal confinement systems with particular emphasis on axisymmetric equilibrium geometries, and tokamaks. The discussion covers three important aspects of plasma physics: Equilibrium, Stability, and Transport. The section on equilibrium will go through an introdu
Jiangbo Zhou, Lixin Tian, Xinghua Fan
In this paper, we employ the bifurcation theory of planar dynamical systems to investigate the traveling wave solutions of a 2-component of the Degasperis-Procesi equation. The expressions for smooth soliton, kink and antikink solutions are obtained.
Local Luminous Infrared Galaxies: Spatially resolved mid-infrared observations with Spitzer/IRS
astro-ph.COAlmudena Alonso-Herrero, Miguel Pereira-Santaella, George H. Rieke, Luis Colina
Luminous Infrared (IR) Galaxies (LIRGs) are an important cosmological class of galaxies as they are the main contributors to the co-moving star formation rate density of the universe at z=1. In this paper we present a GTO Spitzer IRS program aimed to obtain spectral mapping of a sample of 14 local (d<76Mpc) LIRGs. The data cubes map, at least, the central 20
V. Tejedor, O. Bénichou, R. Voituriez
We present a general framework, applicable to a broad class of random walks on complex networks, which provides a rigorous lower bound for the mean first-passage time of a random walker to a target site averaged over its starting position, the so-called global mean first-passage time (GMFPT). This bound is simply expressed in terms of the equilibrium distrib
Martina Avellino
This thesis examines some of the more fundamental requirements of a successful quantum computation, namely the ability to transmit quantum information with maximum efficiency, and the creation of entanglement. I focus specifically on neutron entanglement, showing that the spins of two or more distinct neutrons can be measurably entangled by forward-scatterin
Nicolas Ressayre
Let $G$ be a complex connected reductive algebraic group and $G/B$ denote the flag variety of $G$. A $G$-homogeneous space $G/H$ is said to be {\it spherical} if $H$ acts on $G/B$ with finitely many orbits. A class of spherical homogeneous spaces containing the tori, the complete homogeneous spaces and the group $G$ (viewed as a $G\times G$-homogeneous space
B. Julia-Diaz, M. Mele-Messeguer, M. Guilleumas, A. Polls
The dynamics of an F=1 spinor condensate in a two-well potential is studied within the framework of the Gross-Pitaevskii equation. We derive two-mode equations relating the population imbalances, the phase differences among the condensates at each side of the barrier and the time evolution of the different Zeeman populations for the case of small population
Daniel A. Shaddock
The Laser Interferometer Space Antenna will detect gravitational waves with frequencies from 0.1 mHz to 1 Hz. This article provides a brief overview of LISA's science goals followed by a tutorial of the LISA measurement concept.
C. Burrage, J. Jaeckel, J. Redondo, A. Ringwald
Observations of the temperature anisotropies induced as light from the CMB passes through large scale structures in the late universe are a sensitive probe of the interactions of photons in such environments. In extensions of the Standard Model which give rise to mini-charged particles, photons propagating through transverse magnetic fields can be lost to pa
Nicolas Fournier
We prove the uniqueness of bounded solutions for the spatially homogeneous Fokker-Planck-Landau equation with a Coulomb potential. Since the local (in time) existence of such solutions has been proved by Arsen'ev-Peskov (1977), we deduce a local well-posedness result. The stability with respect to the initial condition is also checked.
Estimating the Gumbel scale parameter for local alignment of random sequences by importance sampling with stopping times
math.STYonil Park, Sergey Sheetlin, John L. Spouge
The gapped local alignment score of two random sequences follows a Gumbel distribution. If computers could estimate the parameters of the Gumbel distribution within one second, the use of arbitrary alignment scoring schemes could increase the sensitivity of searching biological sequence databases over the web. Accordingly, this article gives a novel equation
Self-assembly of liquid crystal block copolymer PEG-b-smectic polymer in pure state and in dilute aqueous solution
cond-mat.softB. Xu, R. Pinol, M. Nono-Djamen, S. Pensec
A series of amphiphilic LC block copolymers, in which the hydrophobic block is a smectic polymer poly(4-methoxyphenyl 4-(6-acryloyloxy-hexyloxy)-benzoate) (PA6ester1) and the hydrophilic block is polyethyleneglycol (PEG), were synthesized and characterized. The self-assembly of one of them in both the pure state and the dilute aqueous solution was investigat
M. De Becker, G. Rauw, N. Linder
The transition from early Of stars to WN type objects is poorly understood. O-type supergiants with emission lines (OIf+) are considered to be intermediate between these two classes. The scope of this paper is to investigate the spectral variability of three Of+ supergiants. We constituted spectral time series of unprecedented quality for our targets (~ 200
M. Martini, G. Chanfray, M. Ericson, J. Marteau
We present a model for neutrino-nucleus scattering in the energy region relevant for present and forthcoming neutrino-oscillation experiments. The model is based on the RPA treatment of the nuclear responses in the quasi-elastic and Delta-resonance region. It includes also in a phenomenological way nucleon knock-out. It aims at the description, within a sing
Ana Arribas-Gil
In this work we deal with parameter estimation in a latent variable model, namely the multiple-hidden i.i.d. model, which is derived from multiple alignment algorithms. We first provide a rigorous formalism for the homology structure of k sequences related by a star-shaped phylogenetic tree in the context of multiple alignment based on indel evolution models
Barbara Hammer, Alexander Hasenfuß, Fabrice Rossi
Median clustering extends popular neural data analysis methods such as the self-organizing map or neural gas to general data structures given by a dissimilarity matrix only. This offers flexible and robust global data inspection methods which are particularly suited for a variety of data as occurs in biomedical domains. In this chapter, we give an overview a
Marie Doumic Jauffret, Peter S. Kim, Benoît Perthame
We analyze the asymptotic behavior of a partial differential equation (PDE) model for hematopoiesis. This PDE model is derived from the original agent-based model formulated by (Roeder et al., Nat. Med., 2006), and it describes the progression of blood cell development from the stem cell to the terminally differentiated state. To conduct our analysis, we sta
Guo-Jie Gao, Jerzy Blawzdziewicz, Corey S. O'Hern
We enumerate and classify nearly all of the possible mechanically stable (MS) packings of bidipserse mixtures of frictionless disks in small sheared systems. We find that MS packings form continuous geometrical families, where each family is defined by its particular network of particle contacts. We also monitor the dynamics of MS packings along geometrical
Michel Verleysen, Fabrice Rossi, Damien François
The selection of features that are relevant for a prediction or classification problem is an important problem in many domains involving high-dimensional data. Selecting features helps fighting the curse of dimensionality, improving the performances of prediction or classification methods, and interpreting the application. In a nonlinear context, the mutual
I. V. Kostyakov, V. V. Kuratov
Gauge fields of semisimple groups of internal symmetries are massless and require the special techniques for guarantee their mass. Massive mechanisms usually contain transformations of shifts typical to nonsemisimple groups. We show that under the localization of nonsemisimple internal symmetry the gauge fields corresponding to translation generators are mas
Amr Rizk, Markus Fidler
Fractional Brownian motion (fBm) emerged as a useful model for self-similar and long-range dependent Internet traffic. Approximate performance measures are known from large deviations theory for single queuing systems with fBm through traffic. In this paper we derive end-to-end performance bounds for a through flow in a network of tandem queues under fBm cro
A. Franckowiak, C. Akerlof, D. F. Cowen, M. Kowalski
Three-quarters of the 1 cubic kilometer neutrino telescope IceCube is currently taking data. Current models predict high-energy neutrino emission from transient objects like supernovae (SNe) and gammaray bursts (GRBs). To increase the sensitivity to such transient objects we have set up an optical follow-up program that triggers optical observations on multi
Actin based propulsion: Intriguing interplay between material properties and growth processes
cond-mat.softKarin John, Denis Caillerie, Philippe Peyla, Mourad Ismail
Eukaryotic cells and intracellular pathogens such as bacteria or viruses utilize the actin polymerization machinery to propel themselves forward. Thereby, the onset of motion and choice of direction may be the result of a spontaneous symmetry-breaking or might be triggered by external signals and preexisting asymmetries, e.g. through a previous septation in
Lyderic Bocquet, Elisabeth Charlaix
Nanofluidics has emerged recently in the footsteps of microfluidics, following the quest of scale reduction inherent to nanotechnologies. By definition, nanofluidics explores transport phenomena of fluids at the nanometer scales. Why is the nanometer scale specific ? What fluid properties are probed at nanometric scales ? In other words, why 'nanofluidics' d
W. -R. Hamann, G. Graefener, L. M. Oskinova, A. Feldmeier
Analyzing the spectra from Wolf-Rayet stars requires adequate non-LTE modeling of their expanding atmosphere. The numerical schemes for solving the radiative transfer in the co-moving frame of reference have been developed by Mihalas and co-workers 30 years ago. The most elaborate codes can cope today with many hundred explicit non-LTE levels or super-levels
A Mechanism for the Oxygen and Iron Bimodal Radial Distribution Formation in the Disc of our Galaxy
astro-ph.GAI. A. Acharova, J. R. D. Lépine, Yu. N. Mishurov, B. M. Shustov
Recently it has been proposed that there are two types of SN Ia progenitors -- short-lived and long-lived. On the basis of this idea, we develope a theory of a unified mechanism for the formation of the bimodal radial distribution of iron and oxygen in the Galactic disc. The underlying cause for the formation of the fine structure of the radial abundance pat
V. S. Popov, M. A. Trusov
Generating functions and sum rules are discussed for transition probabilities between quantum oscillator eigenstates with time-dependent parameters.
Any l-state approximate solutions of the Manning-Rosen potential by the Nikiforov-Uvarov method
quant-phSameer M. Ikhdair, Ramazan Sever
The Schrodinger equation for the Manning-Rosen potential with the centrifugal term is solved approximately to obtain bound states energies. Additionally, the corresponding wave functions are expressed by the Jacobi polynomials. The Nikiforov-Uvarov (NU) method is used in the calculations. To show the accuracy of our results, we calculate the eigenvalues nume
V. V. Gvaramadze, S. Fabrika, W. -R. Hamann, O. Sholukhova
We report the serendipitous discovery of a ring nebula around a candidate Wolf-Rayet (WR) star, HBHA 4202-22, in Cygnus using the Spitzer Space Telescope archival data. Our spectroscopic follow-up observations confirmed the WR nature of this star (we named it WR138a) and showed that it belongs to the WN8-9h subtype. We thereby add a new example to the known
C. Giusti, A. Meucci, F. D. Pacati, J. A. Caballero
Relativistic models developed for the exclusive and inclusive quasielastic (QE) electron scattering have been extended to charged-current (CC) and neutral-current (NC) neutrino-nucleus scattering. Different descriptions of final-state interactions (FSI) are compared. For the inclusive electron scattering the relativistic Green's function approach is compared
M. Alfaro, F. Marcellan, A. Pena, M. L. Rezola
Let $\{P_n \}_{n\ge0}$ be a sequence of monic orthogonal polynomials with respect to a quasi--definite linear functional $u$ and $\{Q_n \}_{n\ge0}$ a sequence of polynomials defined by $$Q_n(x)=P_n(x)+s_n P_{n-1}(x)+t_n P_{n-2}(x),\quad n\ge1,$$ with $t_n \not= 0$ for $n\ge2$. We obtain a new characterization of the orthogonality of the sequence $\{Q_n \}_{n
A. M. Melnik, A. K. Dambis
The proper motions of OB-associations computed using the old (Hipparcos 1997} and new (van Leeuwen 2007) reductions of the Hipparcos data are in a good agreement with each other. The Galactic rotation curve derived from an analysis of line-of-sight velocities and proper motions of OB-associations is almost flat in the 3-kpc neighborhood of the Sun. The angul
M. Alfaro, J. J. Moreno-Balcazar, A. Pena, M. L. Rezola
We consider a generalization of the classical Hermite polynomials by the addition of terms involving derivatives in the inner product. This type of generalization has been studied in the literature from the point of view of the algebraic properties. Thus, our aim is to study the asymptotics of this sequence of nonstandard orthogonal polynomials. In fact, we
P. Di Francesco, R. Kedem
We prove a conjecture of Kontsevich regarding the solutions of rank two recursion relations for non-commutative variables which, in the commutative case, reduce to rank two cluster algebras of affine type. The conjecture states that solutions are positive Laurent polynomials in the initial cluster variables. We prove this by use of a non-commutative version
Marcelo J. Moreira
This paper uses the invariance principle to solve the incidental parameter problem of [Econometrica 16 (1948) 1--32]. We seek group actions that preserve the structural parameter and yield a maximal invariant in the parameter space with fixed dimension. M-estimation from the likelihood of the maximal invariant statistic yields the maximum invariant likelihoo
S. Yu. Gavrilkin, O. M. Ivanenko, V. P. Martovitskii, K. V. Mitsen
We have measured the heat capacity of YBa2Cu3O6+d for 0.7<d<0.8 between 1.8 and 300K. It was found that doping dependences of specific heat jump and temperature of heat capacity jump contradict to the assumption of spatially homogeneous electronic density. The results suggest that the transition from 60K to 90K phase has a percolative nature and the structur
Notes on disentangling of spectra II. Intrinsic line-profile variability due to Cepheid pulsations
astro-ph.SRP. Hadrava, M. Slechta, P. Skoda
The determination of pulsation velocities from observed spectra of Cepheids is needed for the Baade-Wesselink calibration of these primary distance markers. The applicability of the Fourier-disentangling technique for the determination of pulsation velocities of Cepheids and other pulsating stars is studied. The KOREL-code was modified to enable fitting of f
Jiawei Liu, Bruce G. Lindsay
We introduce a semiparametric ``tubular neighborhood'' of a parametric model in the multinomial setting. It consists of all multinomial distributions lying in a distance-based neighborhood of the parametric model of interest. Fitting such a tubular model allows one to use a parametric model while treating it as an approximation to the true distributi
Amit Verma, Anirban Pathak
We have investigated the possibility of observing higher order antibunching (HOA) and higher order subpossonian photon statistics (HOSPS) in five wave mixing and third harmonic generation process. It had been shown that both processes satisfy the criteria of HOA and HOSPS. Further, some observations on the nature of interaction which produces HOA and HOSPS a
R. N. Karasev
In this paper a version of Knaster-Kuratowski-Mazurkiewicz theorem for products of simplices is formulated. Some corollaries for measure partition in the plane and cutting families of sets in the plane by lines are given.
K. V. Mitsen, O. M. Ivanenko
Here we consider the possibility that the Fermi arcs observed in ARPES experiments result from interaction of valence band electrons with negative-U centers (NUCs) which are formed under doping on the pairs of neighboring Cu cations in CuO2 plane. This interaction results in two-particle hybridization and vanishing of the gap over the part of Fermi contour.
G. P. Kapoor, Srijanani Anurag Prasad
In the present paper, the stability of Coalescence Hidden variable Fractal Interpolation Surfaces(CHFIS) is established. The estimates on error in approximation of the data generating function by CHFIS are found when there is a perturbation in independent, dependent and hidden variables. It is proved that any small perturbation in any of the variables of gen
Reinhard Stock
A survey is given of recent QCD theory advances concerning the phase diagram, in particular the indications for a critical point and adjacent first order phase transition at high baryo-chemical potential, and the new ideas concerning a further phase at high $μ_{B}$, the quarkyonic matter phase. The latter state might finally explain the hadro-chemical equili
Fabio Gastaldello, David A. Buote, Pasquale Temi, Fabrizio Brighenti
We present AGN feedback in the interesting cases of two groups: AWM 4 and NGC 5044. AWM 4 is characterized by a combination of properties which seems to defy the paradigm for AGN heating in cluster cores: a flat inner temperature profile indicative of a past, major heating episode which completely erased the cool core, as testified by the high central coolin
Md. Rabiul Islam, Md. Fayzur Rahman
In this paper, a novel method of designing a codebook for noise robust speaker identification purpose utilizing Genetic Algorithm has been proposed. Wiener filter has been used to remove the background noises from the source speech utterances. Speech features have been extracted using standard speech parameterization method such as LPC, LPCC, RCC, MFCC, (del
Peter Z. G. Qian, Mingyao Ai, C. F. Jeff Wu
New types of designs called nested space-filling designs have been proposed for conducting multiple computer experiments with different levels of accuracy. In this article, we develop several approaches to constructing such designs. The development of these methods also leads to the introduction of several new discrete mathematics concepts, including nested
Simulation of the current dynamics in superconductors: Application to magnetometry measurements
cond-mat.supr-conM. Zehetmayer
A simple model for simulating the current dynamics and the magnetic properties of superconductors is presented. Short simulation times are achieved by solving the differential form of Maxwell's equations inside the sample, whereas integration is only required at the surface to meet the exact boundary conditions. The procedure reveals the time and positio
D. Lamago, M. Hoesch, M. Krisch, R. Heid
Interactions with electronic excitations can soften and/or broaden phonons. They are greatly amplified at wavevectors Q+- that connect parallel (nested) sheets of the Fermi surface. In such a case, called a Kohn anomaly, the phonon dispersion sharply dips and its linewidth has a maximum at Q+-. Here we present results of inelastic x-ray scattering measuremen
Jose Ignacio Iglesias Curto, Uwe Helmke
Decoding of convolutional codes poses a significant challenge for coding theory. Classical methods, based on e.g. Viterbi decoding, suffer from being computationally expensive and are restricted therefore to codes of small complexity. Based on analogies with model predictive optimal control, we propose a new iterative method for convolutional decoding that i
Electric fields in solar magnetic structures due to gradient driven instabilities: heating and acceleration of particles
astro-ph.SRJ. Vranjes, S. Poedts
The electrostatic instabilities driven by the gradients of the density, temperature and magnetic field, are discussed in their application to solar magnetic structures. Strongly growing modes are found for some typical plasma parameters. These instabilities i) imply the presence of electric fields that can accelerate the plasma particles in both perpendicula
Computational Complexities and Breaches in Authentication Frameworks of Broadband Wireless Access
cs.CRRaheel Maqsood Hashmi, Arooj Mubashara Siddiqui, Memoona Jabeen, Khurram S. Alimgeer
Secure access of communication networks has become an increasingly important area of consideration for the communication service providers of present day. Broadband Wireless Access (BWA) networks are proving to be an efficient and cost effective solution for the provisioning of high rate wireless traffic links in static and mobile domains. The secure access
Hegang H. Chen, Ching-Shui Cheng
It is known that all resolution IV regular $2^{n-m}$ designs of run size $N=2^{n-m}$ where $5N/16<n<N/2$ must be projections of the maximal even design with $N/2$ factors and, therefore, are even designs. This paper derives a general and explicit relationship between the wordlength pattern of any even $2^{n-m}$ design and that of its complement in the maxima
Frédéric Butin, Gadi S. Perets
Given $Γ$ a finite subgroup of $\mathbf{SL}_3\mathbb{C}$, we determine how an arbitrary finite dimensional irreducible representation of $\mathbf{SL}_3\mathbb{C}$ decomposes under the action of $Γ$. To the subgroup $Γ$ we attach a generalized Cartan matrix $C_Γ$. Then, inspired by B. Kostant, we decompose the Coxeter element of the Kac-Moody algebra attached
Andreas Schweizer
We present some results on two meromorphic functions from S to the Riemann sphere sharing a number of values where S is a Riemann surface of one of the following types: compact, compact minus finitely many points, the unit disk, a torus, the complex plane.
Dr. G. Padmavathi, Mrs. D. Shanmugapriya
Wireless Sensor networks (WSN) is an emerging technology and have great potential to be employed in critical situations like battlefields and commercial applications such as building, traffic surveillance, habitat monitoring and smart homes and many more scenarios. One of the major challenges wireless sensor networks face today is security. While the deploym
Alexander E. Holroyd
Suppose that red and blue points occur as independent Poisson processes of equal intensity in R^d, and that the red points are matched to the blue points via straight edges in a translation-invariant way. We address several closely related properties of such matchings. We prove that there exist matchings that locally minimize total edge length in d=1 and d>=
P. Richard, K. Nakayama, T. Sato, M. Neupane
We performed an angle-resolved photoemission spectroscopy study of BaFe2As2, which is the parent compound of the so-called 122 phase of the iron-pnictide high-temperature superconductors. We reveal the existence of a Dirac cone in the electronic structure of this material below the spin-density-wave temperature, which is responsible for small spots of high p
Jalpa Bani, Syed S. Rizvi
Rijndael algorithm was unanimously chosen as the Advanced Encryption Standard (AES) by the panel of researchers at National Institute of Standards and Technology (NIST) in October 2000. Since then, Rijndael was destined to be used massively in various software as well as hardware entities for encrypting data. However, a few years back, Daniel Bernstein devis
Andri Mirzal, Masashi Furukawa
We present a new method to accelerate the HITS algorithm by exploiting hyperlink structure of the web graph. The proposed algorithm extends the idea of authority and hub scores from HITS by introducing two diagonal matrices which contain constants that act as weights to make authority pages more authoritative and hub pages more hubby. This method works becau
QoS Provisioning Using Hybrid FSO RF Based Hierarchical Model for Wireless Multimedia Sensor Networks
cs.NISaad Ahmad Khan, Sheheryar Ali Arshad
Our objective is to provide guaranteed packet delivery service in time constrained sensor networks. The wireless network is a highly variable environment, where available link bandwidth may vary with network load. Since multimedia applications require higher bandwidth so we use FSO links for their transmission. The main advantage of FSO links is that they of
Jeremiah Heller, Mircea Voineagu
We establish the analogue of the Friedlander-Mazur conjecture for Teh's reduced Lawson homology groups of real varieties, which says that the reduced Lawson homology of a real quasi-projective variety $X$ vanishes in homological degrees larger than the dimension of $X$ in all weights. As an application we obtain a vanishing of homotopy groups of the mod-
Virginia A. Kilborn, Duncan A. Forbes, David G. Barnes, Baerbel S. Koribalski
We investigate the neutral hydrogen (HI) content of sixteen groups for which we have multi-wavelength data including X-ray observations. Wide-field imaging of the groups was obtained with the 20-cm multibeam system on the 64-m Parkes telescope. We have detected ten previously uncatalogued HI sources, one of which has no visible optical counterpart. We examin
Derek W. Robinson, Adam Sikora
Let $H$ be the symmetric second-order differential operator on $L_2(\Ri)$ with domain $C_c^\infty(\Ri)$ and action $Hφ=-(c φ')'$ where $ c\in W^{1,2}_{\rm loc}(\Ri)$ is a real function which is strictly positive on $\Ri\backslash\{0\}$ but with $c(0)=0$. We give a complete characterization of the self-adjoint extensions and the submarkovian extension
Yields and elliptic flow of $d(\bar{d})$ and $^{3}He(\bar{^{3}He})$ in Au+Au collisions at $\sqrt{s_{_{NN}}} =$ 200 GeV
nucl-exThe STAR Collaboration
We present the $p_{T}$ spectra, elliptic flow ($v_2$) and coalescence parameters $B_{2}$ for $d$, $\bar{d}$ ($1<p_{T}<4$ GeV/c) and $B_{3}$ for $^{3}He$, $\bar{^{3}He}$ ($2<p_{T}<6$ GeV/c) produced at mid-rapidity in Au+Au col lisions at $\sqrt{s_{_{NN}}} = 200$ GeV. The results are measured in the STAR experiment at RHIC. The spectra of the light nuclei sho
J. A. ZuHone, M. Markevitch
Though feedback from central active galactic nuclei provides an attractive solution to the problem of overcooling in galaxy cluster cores, another possible source of heating may come from ``sloshing'' of the cluster core gas initiated by mergers. We present a set of simulations of galaxy cluster mergers with subclusters in order to determine the amou
Elshad Allahyarov, Philip L. Taylor, Hartmut Löwen
We have performed simulations to study how increasing humidity affects the structure of Nafion-like ionomers under conditions of low sulfonate concentration and low humidity. At the onset of membrane hydration, the clusters split into smaller parts. These subsequently swell, but then maintain constant the number of sulfonates per cluster. We find that the di
Radiative-Recoil Corrections to Hyperfine Splitting: Polarization Insertions in the Muon Factor
hep-phMichael I. Eides, Valery A. Shelyuto
We consider three-loop radiative-recoil corrections to hyperfine splitting in muonium due to insertions of one-loop polarization operator in the muon factor. The contribution produced by electron polarization insertions are enhanced by the large logarithm of the electron-muon mass ratio. We obtained all single-logarithmic and nonlogarithmic radiative-recoil
X. Q. Huang
In this study, a possible non-quasiparticle glue for superconductivity of both conventional and unconventional superconductors is explored in a pure electron picture. It is shown clearly that the moving electrons due to the electromagnetic interaction can self-organize into some quasi-one-dimensional real-space charge stripes, which can further form some the
Sangwoo Ha, Andrey A. Sukhorukov, Kokou B. Dossou, Lindsay C. Botten
We demonstrate that the spatial profiles of both propagating and evanescent Bloch-modes in a periodic structure can be extracted from a single measurement of electric field at the specified optical wavelength. We develop a systematic extraction procedure by extending the concepts of high-resolution spectral methods previously developed for temporal data seri
Zotin K. -H. Chu
We make remarks on Sofos {\it et al.}'s [{\it Phys. Rev. E} 79, 026305 (2009)] paper. The focus is about the monotonicity of the slip length of which it is different from previous similar numerical simulation. We also offer a possible explanation for this.
H. Wang, M. Hofheinz, J. Wenner, M. Ansmann
The quality factor and energy decay time of superconducting resonators have been measured as a function of material, geometry, and magnetic field. Once the dissipation of trapped magnetic vortices is minimized, we identify surface two-level states (TLS) as an important decay mechanism. A wide gap between the center conductor and the ground plane, as well as
Peter Berg, Justin Findlay
A molten carbonate fuel cell (MCFC) is an electro-chemical energy conversion technology that runs on natural gas and employs a molten salt electrolyte. In order to keep the electrolyte in this state, the cell must be kept at a temperature above 500 C, eliminating the need for precious metals as the catalyst. There has been only a limited amount of research o
Adam L. Kraus, Lynne A. Hillenbrand
Multiple star systems are commonly assumed to form coevally; they thus provide the anchor for most calibrations of stellar evolutionary models. In this paper we study the binary population of the Taurus-Auriga association, using the component positions in an HR diagram in order to quantify the frequency and degree of coevality in young binary systems. After
Jon Woolf
The space of stability conditions on a triangulated category is naturally partitioned into subsets $U(A)$ of stability conditions with a given heart $A$. If $A$ has finite length and $n$ simple objects then $U(A)$ has a simple geometry, depending only on $n$. Furthermore, Bridgeland has shown that if $B$ is obtained from $A$ by a simple tilt, i.e.\ by tiltin
John C. Baez, John Huerta
Supersymmetry is deeply related to division algebras. Nonabelian Yang-Mills fields minimally coupled to massless spinors are supersymmetric if and only if the dimension of spacetime is 3, 4, 6 or 10. The same is true for the Green-Schwarz superstring. In both cases, supersymmetry relies on the vanishing of a certain trilinear expression involving a spinor fi
Inga Kuznetsova
We study particle production and its density evolution and equilibration in hot dense medium. One type of hot dense medium, which we study, is hadronic gas produced at quark gluon plasma hadronization in heavy ions collisions in SPS, RHIC and LHC experiments. We study hadron production at non-equilibrium quark gluon plasma hadronization and their evolution i
Gauge propagator and physical consistency of the CPT-even part of the Standard Model Extension
hep-thRodolfo Casana, Manoel M. Ferreira, Adalto R. Gomes, Paulo R. D. Pinheiro
In this work, we explicitly evaluate the gauge propagator of the Maxwell theory supplemented by the CPT-even term of the SME. First, we specialize our evaluation for the parity-odd sector of the tensor $W_{\mu \nu \rho \sigma}$,\ using a parametrization that retains only the three nonbirefringent coefficients. From the poles of the propagator, it is shown th
D. Korotkin, V. Shramchenko
In this paper we study the Fuchsian Riemann-Hilbert (inverse monodromy) problem corresponding to Frobenius structures on Hurwitz spaces. We find a solution to this Riemann-Hilbert problem in terms of integrals of certain meromorphic differentials over a basis of an appropriate relative homology space, study the corresponding monodromy group and compute the m
Variational ansatz for the nonlinear Landau-Zener problem for cold atom association
cond-mat.quant-gasA. Ishkhanyan, B. Joulakian, K. -A. Suominen
We present a rigorous analysis of the Landau-Zener linear-in-time term crossing problem for quadratic-nonlinear systems relevant to the coherent association of ultracold atoms in degenerate quantum gases. Our treatment is based on an exact third-order nonlinear differential equation for the molecular state probability. Applying a variational two-term ansatz,