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May 2010 arXiv papers — page 22

Showing 2,1012,200 of 5,722 papers

  1. A. F. Kholtygin, S. N. Fabrika, N. A. Drake, V. D. Bychkov

    Based on an analysis of the catalog of magnetic fields, we have investigated the statistical properties of the mean magnetic fields for OB stars. We show that the mean effective magnetic field ${\cal B}$ of a star can be used as a statistically significant characteristic of its magnetic field. No correlation has been found between the mean magnetic field str

  2. Wolfgang Ring, Luca Rondi

    We numerically implement the variational approach for reconstruction in the inverse crack and cavity problems developed by one of the authors. The method is based on a suitably adapted free-discontinuity problem. Its main features are the use of phase-field functions to describe the defects to be reconstructed and the use of perimeter-like penalizations to r

  3. Norbert Hegyvári, Francois Hennecart, Alain Plagne

    Starting from a result of Stewart, Tijdeman and Ruzsa on iterated difference sequences, we introduce the notion of iterated compositions of linear operations. We prove a general result on the stability of such compositions (with bounded coefficients) on sets of integers having a positive upper density.

  4. M. A. Campisi, L. -X. Li, P. Jakobsson

    We study the luminosity function (LF), the comoving rate and the detection rate of Long Gamma-Ray Burst (LGRBs) to high redshift, using galaxy catalogues constructed by combining high-resolution N-body simulations with semi-analytic models of galaxy formation. We assume the collapsar model and different metallicity thresholds, and conclude that LGRBs are not

  5. C. Ferrari

    The existence of cosmic rays and weak magnetic fields in the intracluster volume has been well proven by deep radio observations of galaxy clusters. However a detailed physical characterization of the non-thermal component of large scale-structures, relevant for high-precision cosmology, is still missing. I will show the importance of combining numerical and

  6. Mario Collura, Dragi Karevski

    We analyze the coherent quantum evolution of a many-particle system after slowly sweeping a power-law confining potential. The amplitude of the confining potential is varied in time along a power-law ramp such that the many-particle system finally reaches or crosses a critical point. Under this protocol we derive general scaling laws for the density of excit

  7. Jaykrishna Singh, Eric R. Bittner

    We consider here the non-adiabatic energy transfer dynamics for a model bi-chromophore system consisting of a perylenediimide unit linked to a ladder-type poly-(para-phenylene) oligomer. Starting from a semi-empirical parameterization of a model electron/phonon Hamiltonian, we compute the golden-rule rate for energy transfer from the LPPP5 donor to the PDI a

  8. Erik Aurell, Charles Ollion, Yasser Roudi

    We study the performance and convergence properties of the Susceptibility Propagation (SusP) algorithm for solving the Inverse Ising problem. We first study how the temperature parameter (T) in a Sherrington-Kirkpatrick model generating the data influences the performance and convergence of the algorithm. We find that at the high temperature regime (T>4), th

  9. Yu Chen, Nicolas Regnault, Robson Ferreira

    We study theoretically the effect of a lateral electric field on the magneto-polaron states in a quantum cascade laser under a quantizing magnetic field. We show that this problem fits the original Fano model of a discrete state coupled to a continuum, present a detailed analysis of magneto-Stark polaron resonances, and finally discuss the strong consequence

  10. Sebastien Murphy

    As the intensity of neutrino beams produced at accelerators increases, important systematic errors due to poor knowledge of production cross sections for pions and kaons arise. Among other goals, the NA61/SHINE (SHINE=SPS Heavy Ion and Neutrino Experiment) detector at CERN SPS aims at precision hadro-production measurements to characterise the neutrino beam

  11. Eric R. Bittner, Donald J. Kouri

    In my talk I will present an overview of our recent work involving the use of supersymmetric quantum mechanics (SUSY-QM). I begin by discussing the mathematical underpinnings of SUSY-QM and then discuss how we have used this for developing novel theoretical and numerical approaches suitable for studying molecular systems. I will conclude by discussing our at

  12. C. Arnaboldi, C. Brofferio, A. Bryant, C. Bucci

    High purity TeO2 crystals are produced to be used for the search for the neutrinoless double beta decay of 130Te. Dedicated production lines for raw material synthesis, crystal growth and surface processing were built compliant with radio-purity constraints specific to rare event physics experiments. High sensitivity measurements of radio-isotope concentrati

  13. Kohei Hattori, Yuzuru Yoshii

    We present theoretical calculations for the differential distribution of stellar orbital eccentricity in a galaxy halo, assuming that the stars constitute a spherical, collisionless system in dynamical equilibrium with a dark matter halo. In order to define the eccentricity e of a halo star for given energy E and angular momentum L, we adopt two types of gra

  14. T. Felipe, E. Khomenko, M. Collados

    Three-dimensional numerical simulations of magnetoacoustic wave propagation are performed in a sunspot atmosphere with a computational domain covering from the photosphere to the chromosphere. The wave source, with properties resembling the solar spectrum, is located at different distances from the axis of the sunspot for each simulation. These results are c

  15. Arnaud Beauville, Christophe Ritzenthaler

    Let A be a principally polarized abelian threefold over a perfect field k, not isomorphic to a product over the algebraic closure of k. There exists a canonical extension k' of k, of degree 1 or 2, such that A becomes isomorphic to a Jacobian over k'. The aim of this note is to give a geometric construction of this extension.

  16. F. Vissani, G. Pagliaroli, F. Rossi-Torres

    We discuss the importance of observing supernova neutrinos. By analyzing the SN1987A observations of Kamiokande-II, IMB and Baksan, we show that they provide a 2.5σ support to the standard scenario for the explosion. We discuss in this context the use of neutrinos as trigger for the search of the gravity wave impulsive emission. We derive a bound on the neut

  17. Diego Rybski, Hernán D. Rozenfeld, Jürgen P. Kropp

    We propose a fluctuation analysis to quantify spatial correlations in complex networks. The approach considers the sequences of degrees along shortest paths in the networks and quantifies the fluctuations in analogy to time series. In this work, the Barabasi-Albert (BA) model, the Cayley tree at the percolation transition, a fractal network model, and exampl

  18. Rolando Gaitan Deveras

    A perturbative regime based on contorsion as a dynamical variable and metric as a (classical) fixed background, is performed in the context of a pure Yang-Mills formulation based on $GL(3,R)$ gauge group. In the massless case we show that the theory propagates three degrees of freedom and only one is a non-unitary mode. Next, we introduce quadratical terms d

  19. Martin Kalina, Jan Paseka, Zdenka Riečanová

    Special types of effect algebras $E$ called sharply dominating and S-dominating were introduced by S. Gudder in \cite{gudder1,gudder2}. We prove statements about connections between sharp orthocompleteness, sharp dominancy and completeness of $E$. Namely we prove that in every sharply orthocomplete S-dominating effect algebra $E$ the set of sharp elements an

  20. Birgit Hein, Gregor Tanner

    Quantum algorithms for searching one or more marked items on a d-dimensional lattice provide an extension of Grover's search algorithm including a spatial component. We demonstrate that these lattice search algorithms can be viewed in terms of the level dynamics near an avoided crossing of a one-parameter family of quantum random walks. We give approxima

  21. Guo Chuan Thiang

    We investigate the problem of finding the optimal convex decomposition of a bipartite quantum state into a separable part and a positive remainder, in which the weight of the separable part is maximal. This weight is naturally identified with the degree of separability of the state. In a recent work, the problem was solved for two-qubit states using semidefi

  22. A. Adare, S. Afanasiev, C. Aidala, N. N. Ajitanand

    The PHENIX experiment at the Relativistic Heavy Ion Collider has measured the invariant differential cross section for production of K^0_S , ω, ηprime, and ϕmesons in p + p collisions at = 200 GeV. Measurements ωand ϕproduction in different decay channels give consistent results. New results for the ϕare in agreement with previously published data and extend

  23. Giancarlo Rossi, Massimo Testa

    We provide an example of a 0-dimensional field theory where rooting does not work.

  24. Arabinda Haldar, Niraj K. Singh, K. G. Suresh, A. K. Nigam

    Magnetic field and time induced steps have been observed in the recently discovered ternary silicide R6Co1.67Si3. Huge relaxation steps are observed across different loops in the low temperature magnetization isotherms. Giant relaxation present in this system indicates the existence of incubation time to get the saturated moment at a certain field. Measureme

  25. Arabinda Haldar, K. G. Suresh, A. K. Nigam, A. A. Coelho

    Effects of Al, Mn and Sb dopings in CeFe2 and effect of applied pressure have been investigated. Al doping gives rise to the FM-AFM transition and a reduction in the magnetic moment and TC values, clearly indicating the growth of the AFM component. Mn and Sb dopings only cause a reduction in TC value. It is found that in general external pressure enhances th

  26. Patrick W. Dondl, Luca Mugnai, Matthias Röger

    We consider the problem of minimizing Euler's elastica energy for simple closed curves confined to the unit disk. We approximate a simple closed curve by the zero level set of a function with values +1 on the inside and -1 on the outside of the curve. The outer container now becomes just the domain of the phase field. Diffuse approximations of the elasti

  27. Hiroaki Ito, Saku Tsuneta, Daikou Shiota, Munetoshi Tokumaru

    Observations of the polar region of the Sun are critically important for understanding the solar dynamo and the acceleration of solar wind. We carried out precise magnetic observations on both the North polar region and the quiet Sun at the East limb with the Spectro-Polarimeter of the Solar Optical Telescope aboard Hinode to characterize the polar region wi

  28. Carlos Marques Afonso, Alfredo Barbosa Henriques, Paulo Vargas Moniz

    A simple inflationary model based on loop quantum cosmology is considered. Within this framework, we show that inflation does not necessarily erase the infor- mation prior to its onset, but that such information may leave its imprint in the energy-spectrum of the gravitational-waves generated at these earliest of times.

  29. V. N. Mantsevich, N. S. Maslova

    Spatial distribution of local tunneling conductivity was investigated for deep and shallow impurities on semiconductor surfaces. Non-equilibrium Coulomb interaction and interference effects were taken into account and analyzed theoretically with the help of Keldysh formalism. Two models were investigated: mean field self-consistent approach for shallow impur

  30. Pavel Cahyna, Eric Nardon

    General formula describing both the divertor strike point splitting and width of magnetic islands created by resonant magnetic perturbations (RMPs) in a poloidally diverted tokamak equilibrium is derived. Under the assumption that the RMP is produced by coils at the low-field side such as those used to control edge localized modes (ELMs) it is demonstrated t

  31. Arabinda Haldar, Niraj K. Singh, Ya. Mudryk, K. G. Suresh

    Using x-ray powder diffraction technique at various temperatures and applied magnetic fields, we have studied the magnetostructural properties of Ce(Fe0.95Si0.05)2. The x-ray diffraction data establish quantitative relationships between bulk magnetization and the evolution of structurally distinct phases with magnetic field and temperature, and confirm the d

  32. Belkacem Serrour, Alex Arenas, Sergio Gomez

    The study of the sub-structure of complex networks is of major importance to relate topology and functionality. Many efforts have been devoted to the analysis of the modular structure of networks using the quality function known as modularity. However, generally speaking, the relation between topological modules and functional groups is still unknown, and de

  33. Vincenzo Branchina, Dario Zappalà

    The vacuum fluctuations of all quantum fields filling the universe are supposed to leave enormous energy and pressure contributions which are incompatible with observations. It has been recently suggested that, when the effective nature of quantum field theories is properly taken into account, vacuum fluctuations behave as a relativistic gas rather than as a

  34. L. Fossati, C. A. Haswell, C. S. Froning, L. Hebb

    We present near-UV transmission spectroscopy of the highly irradiated transiting exoplanet WASP-12b, obtained with the Cosmic Origins Spectrograph on the Hubble Space Telescope. The spectra cover three distinct wavelength ranges: NUVA (2539-2580 Å), NUVB (2655-2696 Å), and NUVC (2770-2811 Å). Three independent methods all reveal enhanced transit depths attri

  35. M. C. March, G. D. Starkman, R. Trotta, P. M. Vaudrevange

    While Bayesian model selection is a useful tool to discriminate between competing cosmological models, it only gives a relative rather than an absolute measure of how good a model is. Bayesian doubt introduces an unknown benchmark model against which the known models are compared, thereby obtaining an absolute measure of model performance in a Bayesian frame

  36. Andreas Bernig

    The spaces of Sp(n)-, Sp(n)U(1)- and Sp(n)Sp(1)- invariant, translation invariant, continuous convex valuations on the quaternionic vector space H^n are studied. Combinatorial dimension formulas involving Young diagrams and Schur polynomials are proved.

  37. D. Alba, H. W. Crater, L. Lusanna

    The rest-frame instant form of the positive-energy part of the open Nambu string is developed. The string is described as a decoupled non-local canonical non-covariant Newton-Wigner center of mass plus a canonical basis of Wigner-covariant relative variables living in the Wigner 3-spaces. The center of mass carries a realization of the Poincare' algebra

  38. Kushal Shah

    Particle motion in a smoothly oscillating non-integrable billiard is known to result in unbounded energy growth. Though the asymptotic energy growth rate of an ensemble of particles in an oscillating chaotic billiard is known to be quadratic, there are no estimates available for smoothly oscillating pseudo-integrable billiards. The energy growth rate in such

  39. Ling Hei Yeung, Manwai Yuen

    In this paper, we study the Euler and Euler-Poisson equations in $R^{N}$, with multiple $γ$-law for pressure function: \begin{equation} P(ρ)=e^{s}\sum_{j=1}^{m}ρ^{γ_{j}}, \end{equation} where all $γ_{i+1}>γ_{i}\geq1$, is the constants. The analytical line solutions are constructed for the systems. It is novel to discover the analytical solutions to handle th

  40. Alexander Gluck, Helmuth Huffel, Sasa Ilijic

    We present a swarm model of Brownian particles with harmonic interactions, where the individuals undergo canonical active Brownian motion, i.e. each Brownian particle can convert internal energy to mechanical energy of motion. We assume the existence of a single global internal energy of the system. Numerical simulations show amorphous swarming behavior as w

  41. D. Mathur, F. A. Rajgara, A. R. Holkundkar, N. K. Gupta

    Intense 3-cycle pulses (10 fs) of 800 nm laser light are utilized to measure energy distributions of ions emitted following Coulomb explosion of Ar$_n$ clusters ($n$=400-900) upon their irradiation by peak intensitis of 5$\times$10$^{14}$ W cm$^{-2}$. The 3-cycle pulses do not afford the cluster sufficient time to undergo Coulomb-driven expansion, resulting

  42. P. Brogueira, J. Dias de Deus

    Based on the non-linear logistic equation we study, in a qualitative and semi-quantitative way, the evolution with energy and saturation of the elastic differential cross-section in $pp(\bar{p}p)$ collisions at high energy. Geometrical scaling occurs at the black disk limit, and scaling develops first for small values of the scaling variable $|t|σ_{tot.}$. O

  43. G. Cessateur, M. Kretzschmar, T. Dudok de Wit, P. Boumier

    Solar flares presumably have an impact on the deepest layers of the solar atmosphere and yet the observational evidence for such an impact is scarce. Using ten years of measurements of the Na D$_{1}$ and Na D$_2$ Fraunhofer lines, measured by GOLF onboard SOHO, we show that this photospheric line is indeed affected by flares. The effect of individual flares

  44. E. González-Alfonso, J. Fischer, K. Isaak, A. Rykala

    The Ultra Luminous InfraRed Galaxy Mrk 231 reveals up to seven rotational lines of water (H2O) in emission, including a very high-lying (E_{upper}=640 K) line detected at a 4sigma level, within the Herschel/SPIRE wavelength range, whereas PACS observations show one H2O line at 78 microns in absorption, as found for other H2O lines previously detected by ISO.

  45. Andrea Scagliarini, Luca Biferale, Mauro Sbragaglia, Kazuyasu Sugiyama

    We compute the continuum thermo-hydrodynamical limit of a new formulation of lattice kinetic equations for thermal compressible flows, recently proposed in [Sbragaglia et al., J. Fluid Mech. 628 299 (2009)]. We show that the hydrodynamical manifold is given by the correct compressible Fourier- Navier-Stokes equations for a perfect fluid. We validate the nume

  46. R. Songmuang, G. Katsaros, E. Monroy, P. Spathis

    We investigate electronic transport in n-i-n GaN nanowires with and without AlN double barriers. The nanowires are grown by catalyst-free, plasma-assisted molecular beam epitaxy enabling abrupt GaN/AlN interfaces as well as longitudinal n-type doping modulation. At low temperature, transport in n-i-n GaN nanowires is dominated by the Coulomb blockade effect.

  47. T. Bermudez, A. bonilla, F. Martínez-Giménez, A. Peris

    We study Li-Yorke chaos and distributional chaos for operators on Banach spaces. More precisely, we characterize Li-Yorke chaos in terms of the existence of irregular vectors. Sufficient "computable" criteria for distributional and Li-Yorke chaos are given, together with the existence of dense scrambled sets under some additional conditions. We also

  48. Amparo Fúster-Sabater

    A joint characterization of reachability (controllability) and observability (constructibility) for linear SISO nonuniformly sampled discrete systems is presented. The work generalizes to the nonuniform sampling the criterion known for the uniform sampling. Emphasis is on the nonuniform sampling sequence, which is believed to be an additional element for ana

  49. Wim de Boer, Karl-Heinz Hoffmann, Andreas Sabellek, Mike Schmanau

    An external magnetic field exerts a Lorentz force on drifting electric charges inside a silicon strip sensor and thus shifts the cluster position of the collected charge. The shift can be related to the Lorentz angle which is typically a few degrees for holes and a few tens of degrees for electrons in a 4 T magnetic field. The Lorentz angle depends upon magn

  50. Shu-Chiuan Chang

    We study the number of acyclic orientations on the generalized two-dimensional Sierpinski gasket $SG_{2,b}(n)$ at stage $n$ with $b$ equal to two and three, and determine the asymptotic behaviors. We also derive upper bounds for the asymptotic growth constants for $SG_{2,b}$ and $d$-dimensional Sierpinski gasket $SG_d$.

  51. Paul Krapivsky, Kirone Mallick

    We investigate a model of chaperone-assisted polymer translocation through a nanopore in a membrane. Translocation is driven by irreversible random sequential absorption of chaperone proteins that bind to the polymer on one side of the membrane. The proteins are larger than the pore and hence the backward motion of the polymer is inhibited. This mechanism re

  52. Tung Ten Yong

    This article presents a discussion of the notion of quantum ontological excess baggage, first proposed by Hardy. It is argued here that this idea does not have the significance as suggested in his paper. It is shown here that if this concept is properly analyzed, it fails to pose any threat to the ontic approaches of quantum theory in general.

  53. Akos Pinter, Volker Ziegler

    We show that essentially the Fibonacci sequence is the unique binary recurrence which contains infinitely many three-term arithmetic progressions. A criterion for general linear recurrences having infinitely many three-term arithmetic progressions is also given.

  54. E. M. Ovsiyuk, V. V. Kisel, V. M. Red'kov

    There are constructed exact solutions of the quantum-mechanical Dirac equation for a spin S=1/2 particle in the space of constant positive curvature, spherical Riemann space, in presence of an external magnetic field, analogue of the homogeneous magnetic field in the Minkowski space. A generalized formula for energy levels, describing quantization of the mot

  55. Neri Merhav

    Threshold effects in the estimation of parameters of non-linearly modulated, continuous-time, wide-band waveforms, are examined from a statistical physics perspective. These threshold effects are shown to be analogous to phase transitions of certain disordered physical systems in thermal equilibrium. The main message, in this work, is in demonstrating that t

  56. S. C. Schuler, A. L. Plunkett, J. R. King, M. H. Pinsonneault

    We have derived Fe abundances of 16 solar-type Pleiades dwarfs by means of an equivalent width analysis of Fe I and Fe II lines in high-resolution spectra obtained with the Hobby - Eberly Telescope and High Resolution Spectrograph. Abundances derived from Fe II lines are larger than those derived from Fe I lines (herein referred to as over-ionization) for st

  57. Fredrick Michael

    Recently we have described materials interface transport coupling rigorously utilizing NEGF nonequilibrium Green's functions, and have discussed the Hamiltonian terms that from Green's theorem and boundary conditions can be rewritten as Self Energy. We derive the application of our theory to the high $Tc$ Superconducting materials interfaces that are

  58. C. Arasa, S. Andersson, H. M. Cuppen, E. F. van Dishoweck

    The ultraviolet (UV) photodissociation of amorphous water ice at different ice temperatures is investigated using molecular dynamics (MD) simulations and analytical potentials. Previous MD calculations of UV photodissociation of amorphous and crystalline water ice at 10 K [S. Andersson et al., J. Chem. Phys. 124, 064715 (2006)] revealed -for both types of ic

  59. Ran Li, Shi Li, Ji-Rong Ren

    The method of anomaly cancellation to derive Hawking radiation initiated by Robinson and Wilczek is applied to 2+1 dimensional stationary black holes. Using the dimensional reduction technique, we find that the near-horizon physics for the fermionic field in the background of the general 2+1 dimensional stationary black hole can be approximated by an infinit

  60. Michael Dine, Fuminobu Takahashi, Tsutomu T. Yanagida

    Discrete R symmetries are interesting from a variety of points of view. They raise the specter, however, of domain walls, which may be cosmologically problematic. In this note, we describe some of the issues. In many schemes for supersymmetry breaking, as we explain, satisfying familiar constraints such as suppression of gravitino production, insures that th

  61. Philippe Laurencot, Christian Stinner

    The large time behaviour of nonnegative solutions to a quasilinear degenerate diffusion equation with a source term depending solely on the gradient is investigated. After a suitable rescaling of time, convergence to a unique profile is shown for global solutions. The proof relies on the half-relaxed limits technique within the theory of viscosity solutions

  62. Pierre Carpentier, Jean-Philippe Chancelier, Guy Cohen, Michel De Lara

    For a sequence of dynamic optimization problems, we aim at discussing a notion of consistency over time. This notion can be informally introduced as follows. At the very first time step $t_0$, the decision maker formulates an optimization problem that yields optimal decision rules for all the forthcoming time step $t_0, t_1, ..., T$; at the next time step $t

  63. Kale Ruta, K. S. Dwarakanath

    We present a multi-wavelength analysis of the merging rich cluster of galaxies Abell 2256. We have observed A2256 at 150 MHz using the Giant Metrewave Radio Telescope and successfully detected the diffuse radio halo and the relic emission over an extent $\sim1.2$ Mpc$^2$. Using this 150 MHz image and the images made using archival observations from the VLA (

  64. L. Tan, Y. Q. Zhang, Z. H. Zhu, L. W. Liu

    The entanglement, purity and energy of two isolated two-level atoms which are initially prepared in Bell state and each interacts with a thermal cavity field are investigated by considering the atomic motion and the field-mode structure. We achieve the analytical solutions of the atomic qubits by using the algebraic dynamical approach and the influences of t

  65. A. F. Lanza, A. S. Bonomo, C. Moutou, I. Pagano

    The CoRoT satellite has recently discovered the transits of a telluric planet across the disc of a late-type magnetically active star dubbed CoRoT-7, while a second planet has been detected after filtering out the radial velocity (hereafter RV) variations due to stellar activity. We investigate the magnetic activity of CoRoT-7 and use the results for a bette

  66. Markus Brede

    In this paper we consider spatial networks that realize a balance between an infrastructure cost (the cost of wire needed to connect the network in space) and communication efficiency, measured by average shortest pathlength. A global optimization procedure yields network topologies in which this balance is optimized. These are compared with network topologi

  67. T. Aaltonen

    We report on a search for direct scalar bottom quark (sbottom) pair production in $p \bar{p}$ collisions at $\sqrt{s}=1.96$~TeV, in events with large missing transverse energy and two jets of hadrons in the final state, where at least one of the jets is required to be identified as originating from a $b$ quark. The study uses a CDF Run~II data sample corresp

  68. Hajime Tanaka, Rie Tanaka

    Suzuki (1998) showed that an imprimitive Q-polynomial association scheme with first multiplicity at least three is either Q-bipartite, Q-antipodal, or with four or six classes. The exceptional case with four classes has recently been ruled out by Cerzo and Suzuki (2009). In this paper, we show the nonexistence of the last case with six classes. Hence Suzuki&

  69. Adrian A. Budini

    In this paper, we develop a quantum-jump approach for describing the photon-emission process of single fluorophore systems coupled to complex classically fluctuating reservoirs. The formalism relies on an open quantum system approach where the dynamic of the system and the reservoir fluctuations are described through a density matrix whose evolution is defin

  70. R. Sych, V. M. Nakariakov, M. Karlicky, S. Anfinogentov

    A phenomenological relationship between oscillations in a sunspot and quasi-periodic pulsations in flaring energy releases at an active region above the sunspot, is established. The analysis of the microwave emission recorded by the Nobeyama Radioheliograph at 17 GHz shows a gradual increase in the power of the 3-min oscillation train in the sunspot associat

  71. W. Zhu, Q. W. Shi, X. R. Wang, X. P. Wang

    An accurate simulation of Green's function and self-energy function of non-interacting electrons in disordered graphenes are performed. Fundamental physical quantities such as the elastic relaxation time τe, the phase velocity vp, and the group velocity vg are evaluated. New features around the Dirac point are revealed, showing hints that multi-scatterin

  72. R. A. Sych, V. M. Nakariakov, S. Anfinogentov, L. Ofman

    A web-based, interactive system for the remote processing of imaging data sets (i.e., EUV, X-ray and microwave) and the automated interactive detection of wave and oscillatory phenomena in the solar atmosphere is presented.The system targets localised, but spatially resolved, phenomena, such as kink, sausage, and longitudinal propagating and standing waves.

  73. T. Sai Chaitanya, Rajiv kumar, V. Sai Krishna, B Shankar Anandh

    In an earlier work (Shankar kumar Jha, A Vyas, O S K S Sastri, Rajkumar Jain & K S Umesh, 'Determination of wavelength of laser light using Modified Newton's rings setup', Physics Education, vol. 22, no.3, 195-202(2005)) reported by our group, a version of Newton's rings experiment called Modified Newton's rings was proposed. The present

  74. John Lee Grenfell, Heike Rauer, Franck Selsis, Lisa Kaltenegger

    After Earth's origin, our host star, the Sun, was shining 20 to 25 percent less brightly than today. Without greenhouse-like conditions to warm the atmosphere, our early planet would have been an ice ball and life may never have evolved. But life did evolve, which indicates that greenhouse gases must have been present on early Earth to warm the planet. E

  75. John Lee Grenfell, Joachim W. Stock, A. Beate C. Patzer, Stefanie Gebauer

    We propose a mechanism for the oxidation of gaseous CO into CO2 occurring on the surface mineral hematite (Fe2O3(s)) in hot, CO2-rich planetary atmospheres, such as Venus. This mechanism is likely to constitute an important source of tropospheric CO2 on Venus and could at least partly address the CO2 stability problem in Venus' stratosphere, since our re

  76. Andrew Berget

    In this note we give a transparent proof of a result of da Cruz and Dias da Silva on the equality of symmetrized decomposable tensors. This will be done by explaining that their result follows from the fact that the coordinate ring of a flag variety is a unique factorization domain.

  77. Anthony M. J. Davis, Eric Lauga

    A fluid droplet located on a super-hydrophobic surface makes contact with the surface only at small isolated regions, and is mostly in contact with the surrounding air. As a result, a fluid in motion near such a surface experiences very low friction, and super-hydrophobic surfaces display strong drag-reduction in the laminar regime. Here we consider theoreti

  78. Phuong Vo, Megan Nunez

    Biofilms are matrix-enclosed microbial communities that grow at interfaces. They exhibit significant phenotypic changes that render them resistant to many antibacterial agents that can kill their free-swimming counterparts. Biofilms in the environment can consist of either a single or multiple microbial species. Previous investigations in this group demonstr

  79. Kazunari Shima, Motomu Tsuda

    The mysterious relation between the large scale structure of the universe and the tiny (Planck) scale structure of the particle physics, e.g. the observed mysterious relation between the (dark) energy density (and the dark matter) of the universe and the origin of the tiny neutrino mass (and the SUSY breaking mass scale) of the particle physics may be explai

  80. Xi Chen, Seyoung Kim, Qihang Lin, Jaime G. Carbonell

    We consider the problem of learning a structured multi-task regression, where the output consists of multiple responses that are related by a graph and the correlated response variables are dependent on the common inputs in a sparse but synergistic manner. Previous methods such as l1/l2-regularized multi-task regression assume that all of the output variable

  81. Wensheng Cao

    In the paper (Osaka J. Math. {\bf 46}: 403-409, 2009), Yang conjectured that a non-elementary subgroup $G$ of $SL(2, \bc)$ containing elliptic elements is discrete if for each elliptic element $g\in G$ the group $< f, g >$ is discrete, where $f\in SL(2,\bc)$ is a test map which is loxodromic or elliptic. The purpose of this paper is to give an affirmative an

  82. Kensuke Inaba, Makoto Yamashita

    We study the finite temperature properties of two-component fermionic atoms trapped in a two-dimensional optical lattice. We apply the self-energy functional approach to the two-dimensional Hubbard model with a harmonic trapping potential, and systematically investigate the thermodynamic properties of this system. We find that entropy and grand potential pro

  83. J. K. Dong, S. Y. Zhou, T. Y. Guan, H. Zhang

    Reply to comment by T. Terashima et al. on &#34;Quantum criticality and nodal superconductivity in the FeAs-based superconductor KFe$_2$As$_2$&#34;

  84. Ricardo Rodriguez, Rainer J. Fries, Enrique Ramirez

    High momentum jets and hadrons can be used as probes for the quark gluon plasma (QGP) formed in nuclear collisions at high energies. We investigate the influence of fluctuations in the fireball on jet quenching observables by comparing propagation of light quarks and gluons through averaged, smooth QGP fireballs with event-by-event jet quenching using realis

  85. Erhan Bayraktar, Song Yao

    In this paper, we analyze a real-valued reflected backward stochastic differential equation (RBSDE) with an unbounded obstacle and an unbounded terminal condition when its generator $f$ has quadratic growth in the $z$-variable. In particular, we obtain existence, comparison, and stability results, and consider the optimal stopping for quadratic $g$-evaluatio

  86. Lingyan Guo

    We prove the existence of an $m$-cluster tilting object in a generalized $m$-cluster category which is $(m+1)$-Calabi-Yau and Hom-finite, arising from an $(m+2)$-Calabi-Yau dg algebra. This is a generalization of the result for the ${m = 1}$ case in Amiot&#39;s Ph.~D.~thesis. Our results apply in particular to higher cluster categories associated to suitable

  87. Bitan Roy, Igor F. Herbut

    A spatially non-uniform superconducting phase is proposed as the electronic variational ground state for the attractive interactions between nearest neighbors on graphene&#39;s honeycomb lattice, close to and right at the filling one half. The state spontaneously breaks the translational invariance of the lattice into the Kekule pattern of bond order paramet

  88. Laura Anderson, Emanuele Delucchi

    We explore a combinatorial theory of linear dependency in complex space, &#34;complex matroids&#34;, with foundations analogous to those for oriented matroids. We give multiple equivalent axiomatizations of complex matroids, showing that this theory captures properties of linear dependency, orthogonality, and determinants over C in much the same way that ori

  89. Nikolay Bobev, Arnab Kundu, Krzysztof Pilch, Nicholas P. Warner

    We consider supersymmetric holographic flows that involve background gauge fields dual to chemical potentials in the boundary field theory. We use a consistent truncation of gauged N=8 supergravity in five dimensions and we give a complete analysis of the supersymmetry conditions for a large family of flows. We examine how the well-known supersymmetric flow

  90. C. P. Burgess, R. Holman, L. Leblond, S. Shandera

    Massless interacting scalar fields in de Sitter space have long been known to experience large fluctuations over length scales larger than Hubble distances. A similar situation arises in condensed matter physics in the vicinity of a critical point, and in this better-understood situation these large fluctuations indicate the failure in this regime of mean-fi

  91. V. V. Bavula

    The algebra $\mS_n$ of one-sided inverses of a polynomial algebra $P_n$ in $n$ variables is obtained from $P_n$ by adding commuting, {\em left} (but not two-sided) inverses of the canonical generators of the algebra $P_n$. The algebra $\mS_n$ is a noncommutative, non-Noetherian algebra of classical Krull dimension $2n$ and of global dimension $n$ which is no

  92. Daniel Green, Zohar Komargodski, Nathan Seiberg, Yuji Tachikawa

    We study the problem of finding exactly marginal deformations of N=1 superconformal field theories in four dimensions. We find that the only way a marginal chiral operator can become not exactly marginal is for it to combine with a conserved current multiplet. Additionally, we find that the space of exactly marginal deformations, also called the &#34;conform

  93. Ulrich Schneider, Lucia Hackermüller, Jens Philipp Ronzheimer, Sebastian Will

    Transport properties are among the defining characteristics of many important phases in condensed matter physics. In the presence of strong correlations they are difficult to predict even for model systems like the Hubbard model. In real materials they are in general obscured by additional complications including impurities, lattice defects or multi-band eff

  94. I. Soszynski, A. Udalski, M. K. Szymanski, M. Kubiak

    The eighth part of the OGLE-III Catalog of Variable Stars (OIII-CVS) contains type II Cepheids in the Small Magellanic Cloud (SMC). The sample consists of 43 objects, including 17 BL Her, 17 W Vir and 9 RV Tau stars (first examples ever found in the SMC). Seven stars have been classified as peculiar W Vir stars - a recently identified subclass of type II Cep

  95. K. Rapedius, C. Elsen, D. Witthaut, S. Wimberger

    We study the tunneling decay of a Bose-Einstein condensate out of tilted optical lattices within the mean-field approximation. We introduce a novel method to calculate also excited resonance eigenstates of the Gross-Pitaevskii equation, based on a grid relaxation procedure with complex absorbing potentials. This algorithm works efficiently in a wide range of

  96. Chiu Man Ho, Djordje Minic, Y. Jack Ng

    We provide a holographic dual description of Milgrom&#39;s scaling associated with galactic rotation curves. Our argument is based on the recent entropic reinterpretation of Newton&#39;s laws of motion. We propose a duality between cold dark matter and modified Newtonian dynamics (MOND). We introduce the concept of MONDian dark matter, and discuss some of it

  97. D. Hunt, G. Korniss, B. K. Szymanski

    We study the effects of nonzero time delays in stochastic synchronization problems with linear couplings in an arbitrary network. Using the known exact threshold value from the theory of differential equations with delays, we provide the synchronizability threshold for an arbitrary network. Further, by constructing the scaling theory of the underlying fluctu

  98. D. Altamirano, Y. Cavecchi, A. Patruno, A. Watts

    We report on the discovery and the timing analysis of the first eclipsing accretion-powered millisecond X-ray pulsar (AMXP): SWIFT J1749.4-2807. The neutron star rotates at a frequency of ~517.9 Hz and is in a binary system with an orbital period of 8.8 hrs and a projected semi-major axis of ~1.90 lt-s. Assuming a neutron star between 0.8 and 2.2 M_o and usi

  99. David Hasler, Ira Herbst

    We consider the ground state of an atom in the framework of non-relativistic qed. We show that the ground state as well as the ground state energy are analytic functions of the coupling constant which couples to the vector potential, under the assumption that the atomic Hamiltonian has a non-degenerate ground state. Moreover, we show that the corresponding e

  100. Andreas Eberlein, Walter Metzner

    We analyze general properties of the effective Nambu two-particle vertex and its renormalization group flow in a spin-singlet superconductor. In a fully spin-rotation invariant form the Nambu vertex can be expressed by only three distinct components. Solving exactly the flow of a mean-field model with reduced BCS and forward scattering interactions, we gain