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January 2010 arXiv papers — page 17

Showing 1,6011,700 of 5,448 papers

  1. Stefano Profumo, Piero Ullio

    If dark matter particles pair annihilate into stable Standard Model particles, a population of energetic, non-thermal electrons and positrons is necessarily produced. The secondary radiation resulting from the energy losses of this non-standard population (including synchrotron and inverse Compton up-scattering of background radiation photons) in turn produc

  2. Luke Bornn, Raphael Gottardo, Arnaud Doucet

    In the literature surrounding Bayesian penalized regression, the two primary choices of prior distribution on the regression coefficients are zero-mean Gaussian and Laplace. While both have been compared numerically and theoretically, there remains little guidance on which to use in real-life situations. We propose two viable solutions to this problem in the

  3. Andrea Banfi, Gavin P. Salam, Giulia Zanderighi

    We present results for matched distributions of a range of dijet event shapes at hadron colliders, combining next-to-leading logarithmic (NLL) accuracy in the resummation exponent, next-to-next-to leading logarithmic (NNLL) accuracy in its expansion and next-to-leading order (NLO) accuracy in a pure alpha_s expansion. This is the first time that such a match

  4. Adrian L. Malec, Ruth Buning, Michael T. Murphy, Nikola Milutinovic

    Molecular transitions recently discovered at redshift z_abs=2.059 toward the bright background quasar J2123-0050 are analysed to limit cosmological variation in the proton-to-electron mass ratio, mu=m_p/m_e. Observed with the Keck telescope, the optical spectrum has the highest resolving power and largest number (86) of H_2 transitions in such analyses so fa

  5. Adrian L. Malec, Ruth Buning, Michael T. Murphy, Nikola Milutinovic

    Molecular transitions recently discovered at redshift z_abs=2.059 toward the bright background quasar J2123-0050 are analysed to limit cosmological variation in the proton-to-electron mass ratio, mu=m_p/m_e. Observed with the Keck telescope, the optical echelle spectrum has the highest resolving power and largest number (86) of H_2 transitions in such analys

  6. Yuk Tung Liu, Zachariah B. Etienne, Stuart L. Shapiro

    We propose a new radial coordinate to write the Kerr metric in puncture form. Unlike the quasi-radial coordinate introduced previously, the horizon radius remains finite in our radial coordinate in the extreme Kerr limit a/M -> 1. This significantly improves the accuracy of the evolution of black holes with spins close to the extreme Kerr limit. We are able

  7. Emmanuel Russ, Yannick Sire

    Let $G$ be a real connected Lie group with polynomial volume growth, endowed with its Haar measure $dx$. Given a $C^2$ positive function $M$ on $G$, we give a sufficient condition for an $L^2$ Poincaré inequality with respect to the measure $M(x)dx$ to hold on $G$. We then establish a non-local Poincaré inequality on $G$ with respect to $M(x)dx$.

  8. Stéphane Nonnenmacher

    These notes describe a new method to investigate the spectral properties if quantum scattering Hamiltonians, developed in collaboration with J. Sjöstrand and M.Zworski. This method consists in constructing a family of "quantized transfer operators" $\{M(z,h)\}$ associated with a classical Poincaré section near some fixed classical energy E. These ope

  9. Rick Ma, Samuel Cheng

    We consider Slepian-Wolf (SW) coding of multiple sources and extend the packing bound and the notion of perfect code from conventional channel coding to SW coding with more than two sources. We then introduce Hamming Codes for Multiple Sources (HCMSs) as a potential solution of perfect SW coding for arbitrary number of terminals. Moreover, we study the case

  10. Carlos T. Simpson

    This is the first draft of a book about higher categories approached by iterating Segal's method, as in Tamsamani's definition of $n$-nerve and Pelissier's thesis. If $M$ is a tractable left proper cartesian model category, we construct a tractable left proper cartesian model structure on the category of $M$-precategories. The procedure can then

  11. Nicolas Delorme, Julie Boiché, Michel Raspaud

    Sport sciences researchers talk about a relative age effect when they observe a biased distribution of elite athletes' birthdates, with an over-representation of those born at the beginning of the competitive year and an under-representation of those born at the end. Using the whole sample of the French male licensed soccer players (n = 1,831,524), our s

  12. N. Abu-Libdeh D. Venus

    Measurements of the ac magnetic susceptibility of perpendicularly magnetized Fe/2ML Ni/W(110) ultrathin films show a clear signature of the dynamics of domain growth and domain density changes in the striped domain pattern that this system supports. The susceptibility peak measured at different constant heating rates in the range 0.20 K/s < R < 0.70 K/s shif

  13. Fabio Bresolin, Grazyna Stasinska, Jose M. Vilchez, Josh D. Simon

    We have obtained deep optical spectrophotometry of 16 planetary nebulae in M33, mostly located in the central two kpc of the galaxy, with the Subaru and Keck telescopes. We have derived electron temperatures and chemical abundances from the detection of the [OIII]4363 line for the whole sample. We have found one object with an extreme nitrogen abundance, 12+

  14. D. Gryaznov, S. Rashkeev, E. A. Kotomin, E. Heifets

    UO2 and (U,Pu)O2 solid solutions (the so-called MOX) nowadays are used as commercial nuclear fuels in many countries. One of the safety issues during the storage of these fuels is related to their self-irradiation that produces and accumulates point defects and helium therein. We present density functional theory (DFT) calculations for UO2, PuO2 and MOX cont

  15. Alberto Lastra, Javier Sanz

    We give a characterization for two different concepts of quasi-analyticity in Carleman ultraholomorphic classes of functions of several variables in polysectors. Also, working with strongly regular sequences, we establish generalizations of Watson&#39;s Lemma under an additional condition related to the growth index of the sequence.

  16. J. McEwen, J. Day, A. Gonzalez, Z. Papp

    A method is presented that allows to solve the Faddeev integral equations of the semirelativistic constituent quark model. In such a model the quark-quark interaction is modeled by a infinitely rising confining potential and the kinetic energy is taken in a relativistic form. We solve the integral equations in Coulomb-Sturmian basis. This basis facilitate an

  17. Martin L. Perl, Holger Mueller

    The majority of astronomers and physicists accept the reality of dark energy but also believe it can only be studied indirectly through observation of the motions of galaxies. This paper opens the experimental question of whether it is possible to directly detect dark energy on earth using atom interferometry through a force hypothetically caused by a gradie

  18. M. Angeles Perez-Garcia

    Neutrino mean free paths in magnetized neutron matter are calculated using the Hartree-Fock approximation with effective Skyrme and Gogny forces in the framework of the Landau Fermi Liquid Theory. It is shown that describing nuclear interaction with Skyrme forces and for magnetic field strengths $log_{10} B(G) \gtrsim 17$, the neutrino mean free paths stay a

  19. Jiren Liu, Daniel Wang, Zhiyuan Li, John R. Peterson

    We present an X-ray spectroscopic study of the nuclear region of the M31 bulge, based on observations of the Xmm-Newton Reflection Grating Spectrometers. The obtained high-resolution grating spectra clearly show individual emission lines of highly-ionized iron and oxygen, which unambiguously confirm the presence of diffuse hot gas in the bulge, as indicated

  20. Alfredo Aranda, J. Lorenzo Díaz-Cruz, Jaime Hernández-Sánchez, Ernest Ma

    In the recently proposed dark left-right gauge model of particle interactions, the left-handed fermion doublet $(ν,e)_L$ is connected to its right-handed counterpart $(n,e)_R$ through a scalar bidoublet, but $ν_L$ couples to $n_R$ only through $ϕ_1^0$ which has no vacuum expectation value. The usual R parity, i.e. $R = (-)^{3B+L+2j}$, can be defined for this

  21. Pablo I. Hurtado, Pedro L. Garrido

    Most systems, when pushed out of equilibrium, respond by building up currents of locally-conserved observables. Understanding how microscopic dynamics determines the averages and fluctuations of these currents is one of the main open problems in nonequilibrium statistical physics. The additivity principle is a theoretical proposal that allows to compute the

  22. Alexander Kusenko, Michael Loewenstein

    In a recent preprint entitled &#34;Searching for dark matter in X-rays: how to check the dark matter origin of a spectral feature&#34; [arXiv:1001.0644v1], the authors have claimed that some archival X-ray data could be used to rule out dark matter in the form of 5-keV sterile neutrinos at the level of 20 sigma. Unfortunately, the limit was derived incorrect

  23. Simon P. Driver

    At the turn of the decade we arguably move from the era of precision cosmology to the era of galaxy formation. One approach to this problem will be via the construction of comprehensive galaxy samples. In this review I take the opportunity to highlight a number of challenges which must be overcome before we can use such data to construct a robust empirical b

  24. James G. Analytis, Jiun-Haw Chu, Yulin Chen, Felipe Corredor

    Shubnikov de Haas (SdH) oscillations and Angle Resolved PhotoEmission Spectroscopy (ARPES) are used to probe the Fermi surface of single crystals of Bi2Se3. We find that SdH and ARPES probes quantitatively agree on measurements of the effective mass and bulk band dispersion. In high carrier density samples, the two probes also agree in the exact position of

  25. Emanuela Dimastrogiovanni, Nicola Bartolo, Sabino Matarrese, Antonio Riotto

    We present a review of vector field models of inflation and, in particular, of the statistical anisotropy and non-Gaussianity predictions of models with SU(2) vector multiplets. Non-Abelian gauge groups introduce a richer amount of predictions compared to the Abelian ones, mostly because of the presence of vector fields self-interactions. Primordial vector f

  26. Florian Graessle, Tobias Kretz

    Pedestrian route choice is a complex, situation- and population-dependent issue. In this contribution an example is presented, where pedestrians can choose among two seemingly similar alternatives. The choice ratio is not even close to being balanced, but almost all pedestrians choose the same alternative. A number of possible causes for this are given.

  27. Jae-Joon Lee, Sangwook Park, John P. Hughes, Patrick O. Slane

    We study the outer-shock structure of the oxygen-rich supernova remnant G292.0+1.8, using a deep observation with the Chandra X-ray Observatory. We measure radial variations of the electron temperature and emission measure that we identify as the outer shock propagating into a medium with a radially decreasing density profile. The inferred ambient density st

  28. G. Fiorentino, R. Contreras Ramos, G. Clementini, M. Marconi

    Variable stars have been identified for the first time in the very metal-poor Blue Compact dwarf galaxy IZw18, using deep multi-band (F606W, F814W)time-series photometry obtained with the Advanced Camera for Surveys (ACS) on board the Hubble Space Telescope (HST). We detected 34 candidate variable stars in the galaxy. We classify three of them as Classical C

  29. Petros Wallden

    In order to construct a quantum theory of gravity, we may have to abandon certain assumptions we were making. In particular, the concept of spacetime as a continuum substratum is questioned. Causal Sets is an attempt to construct a quantum theory of gravity starting with a fundamentally discrete spacetime. In this contribution we review the whole approach, f

  30. Douglas R. Anderson

    In this study, we are concerned with introducing Weyl-Titchmarsh theory for a class of dynamic linear Hamiltonian nabla systems over a half-line on Sturmian time scales. After developing fundamental properties of solutions and regular spectral problems, we introduce the corresponding maximal and minimal operators for the system. Matrix disks are constructed

  31. O. A. T. Dias, V. S. Filho, J. P. B. C. de Melo

    We have applied the light-front formalism to calculate the electromagnetic form factors for the pion and the kaon from two models at low and high energies in order to explore the differences between such models. We have also compared the results for the ratio $F_{K}(Q^2)/F_π(Q^2)$ with the experimental data up to 10 [GeV/c]$^2$ and we have observed that the

  32. Paul D. Feldman, Stephan R. McCandliss, Jeffrey P. Morgenthaler, Carey M. Lisse

    GALEX observations of comet 9P/Tempel 1 using the near ultraviolet (NUV) objective grism were made before, during and after the Deep Impact event that occurred on 2005 July 4 at 05:52:03 UT when a 370 kg NASA spacecraft was maneuvered into the path of the comet. The NUV channel provides usable spectral information in a bandpass covering 2000 - 3400 A with a

  33. M. Vasta, M. J. Barlow, S. Viti, J. A. Yates

    Far-infrared [C ii] 158 micron, [O i] 145 micron and [O i] 63 micron fine structure emission line fluxes were measured from archival Infrared Space Observatory Long Wavelength Spectrometer spectra of 46 extragalactic sources, with 28 sources providing detections in all three lines. For 12 of the sources, the contribution to the [C ii] 158 micron line flux fr

  34. Hans Christian Öttinger

    We use guiding principles from nonequilibrium thermodynamics to develop an admissible set of 13 moment equations for rarefied gas flows. The main benefits of our thermodynamic approach are an explicit entropy expression fulfilling an $H$ theorem and a sound Hamiltonian formulation of the reversible free flight transport. To calculate the entropy and to find

  35. Nolan R. Walborn, Ian D. Howarth, Christopher J. Evans, Paul A. Crowther

    The Onfp class of rotationally broadened, hot spectra was defined some time ago in the Galaxy, where its membership to date numbers only eight. The principal defining characteristic is a broad, centrally reversed He II $λ$4686 emission profile; other emission and absorption lines are also rotationally broadened. Recent surveys in the Magellanic Clouds (MCs)

  36. Philipp A Hoehn, Susan M Scott

    We summarise the new conformal framework of an Anisotropic Future Endless Universe and an Anisotropic Future Singularity. Both new definitions are motivated by, but not restricted to quiescent cosmology and the Weyl curvature hypothesis, which previously only possessed a framework for a classical initial state of the universe, namely the Isotropic Singularit

  37. T. Aste, G. W Delaney, T. Di Matteo

    It has been recently pointed out that local volume fluctuations in granular packings follow remarkably well a shifted and rescaled Gamma distribution named the kGamma distribution [T. Aste, T. Di Matteo, Phys. Rev. E 77 (2008) 021309]. In this paper we confirm, extend and discuss this finding by supporting it with additional experimental and simulation data.

  38. David Chubelaschwili, Ulrich Pinkall

    Motivated by the problem of finding an explicit description of a developable narrow Moebius strip of minimal bending energy, which was first formulated by M. Sadowsky in 1930, we will develop the theory of elastic strips. Recently E.L. Starostin and G.H.M. van der Heijden found a numerical description for an elastic Moebius strip, but did not give an integra

  39. Thierry Bouche

    The idea of a World digital mathematics library (DML) has been around since the turn of the 21th century. We feel that it is time to make it a reality, starting in a modest way from successful bricks that have already been built, but with an ambitious goal in mind. After a brief historical overview of publishing mathematics, an estimate of the size and a cha

  40. Gary W Delaney, T. Di Matteo, Tomaso Aste

    We combine advanced image reconstruction techniques from computed X-ray micro tomography (XCT) with state-of-the-art discrete element method simulations (DEM) to study granular materials. This &#34;virtual-laboratory&#34; platform allows us to access quantities, such as frictional forces, which would be otherwise experimentally immeasurable.

  41. Mark Kaminski, Gert Smolka

    Propositional type theory, first studied by Henkin, is the restriction of simple type theory to a single base type that is interpreted as the set of the two truth values. We show that two constants (falsity and implication) suffice for denotational and deductive completeness. Denotational completeness means that every value of the full set-theoretic type hie

  42. Y. G. Semenov, J. M. Zavada, K. W. Kim

    The long standing problem of inexplicably short spin relaxation in carbon nanotubes (CNTs) is examined. The curvature-mediated spin-orbital interaction is shown to induce fluctuating electron spin precession causing efficient relaxation in a manner analogous to the Dyakonov-Perel mechanism. Our calculation estimates longitudinal (spin-flip) and transversal (

  43. Xiao Tang, Mu Zhu

    Inspired by a growing interest in analyzing network data, we study the problem of node classification on graphs, focusing on approaches based on kernel machines. Conventionally, kernel machines are linear classifiers in the implicit feature space. We argue that linear classification in the feature space of kernels commonly used for graphs is often not enough

  44. Amedeo Balbi

    What can we know about the universe? I outline a few of the fundamental limitations that are posed to our understanding of the cosmos, such as the existence of horizons, the fact that we occupy a specific place in space and time, the possible presence of dark components, the absence of a reliable physical framework to interpret the behaviour of the very earl

  45. F. Tavecchio

    Blazars, radio-loud active galactic nuclei with the relativistic jet closely aligned with the line of sight, dominate the extragalactic sky observed at gamma-ray energies, above 100 MeV. We discuss some of the emission properties of these sources, focusing in particular on the &#34;blazar sequence&#34; and the interpretative models of the high-energy emissio

  46. A. Paizis, R. Farinelli, L. I. Mainardi, L. Titarchuk

    Theoretical and observational support suggests that the spectral evolution of neutron-star LMXBs, including transient hard X-ray tails, may be explained by the interplay between thermal and bulk motion Comptonization. In this framework, we developed a new model for the X-ray spectral fitting XSPEC package which takes into account the effects of both thermal

  47. Luigi De Pascale, Severine Rigot

    We prove the existence of solutions to Monge transport problem between two compactly supported Borel probability measures in the Heisenberg group equipped with its Carnot-Caratheodory distance assuming that the initial measure is absolutely continuous with respect to the Haar measure of the group.

  48. A. Skopenkov

    This note is purely expository. We show how in the course of the Kolmogorov-Arnold solution of Hilbert&#39;s 13-th problem on superpositions there appeared the notion of a basic embedding. A subset K of R^2 is {\it basic} if for each continuous function f:K->R there exist continuous functions g,h:R->R such that f(x,y) = g(x) + h(y) for each point (x,y) in K.

  49. Douglas R. Anderson

    In this study, we are concerned with spectral problems of second-order vector dynamic equations with two-point boundary value conditions and mixed derivatives, where the matrix-valued coefficient of the leading term may be singular, and the domain is non-uniform but finite. A concept of self-adjointness of the boundary conditions is introduced. The self-adjo

  50. A. J. Barker, G. I. Ogilvie

    We study the fate of internal gravity waves, which are excited by tidal forcing by a short-period planet at the interface of convection and radiation zones, approaching the centre of a solar-type star. We study at what amplitude these wave are subject to instabilities. These instabilities lead to wave breaking whenever the amplitude exceeds a critical value.

  51. Jan Moser

    The elementary geometric properties of Jacob&#39;s ladders of the second order lead to a class of new asymptotic formulae for short and microscopic parts of the Hardy-Littlewood integral of $|ζ(1/2+it)|^4$. These formulae cannot be obtained by methods of Balasubramanian, Heath-Brown and Ivic.

  52. Axel Bredenstein, Ansgar Denner, Stefan Dittmaier, Stefano Pozzorini

    We present predictions for top anti-top bottom anti-bottom production at the LHC in next-to-leading order QCD. The precise description of this background process is a prerequisite to observe associated top anti-top Higgs production in the Higgs -> bottom anti-bottom decay channel and to directly measure the top-quark Yukawa coupling at the LHC. The leading-o

  53. P. Toledano, B. Mettout, W. Schranz, G. Krexner

    The ferroelectric order and magnetic field induced effects observed in the spiral phase of MnWO4 are described theoretically. It is demonstrated explicitly that the Dzyaloshinskii-Moriya antisymmetric interactions contribute to the correlation between spins and electric dipoles in the incommensurate and commensurate ferroelectric phases of magnetic multiferr

  54. Robert Bredereck

    The central problem in this work is to compute a ranking of a set of elements which is &#34;closest to&#34; a given set of input rankings of the elements. We define &#34;closest to&#34; in an established way as having the minimum sum of Kendall-Tau distances to each input ranking. Unfortunately, the resulting problem Kemeny consensus is NP-hard for instances

  55. Jiang-Hua Lu

    Let $G$ be a connected semisimple algebraic group over an algebraically closed field of characteristic zero, and let $þ$ be an automorphism of $G$. We give a characterization of $þ$-twisted spherical conjugacy classes in $G$ by a formula for their dimensions in terms of certain elements in the Weyl group of $G$, generalizing a result of N. Cantarini, G. Carn

  56. S. Nandi, A. Pirya, S. Pal, C. Konar

    We present low-frequency observations starting from ~150 MHz with the Giant Metrewave Radio Telescope (GMRT), and high-frequency observations with the Very Large Array (VLA) of two large radio galaxies 3C46 and 3C452. These observations were made with the objectives of estimating their spectral ages and examining any evidence of diffuse extended emission at

  57. J. W. Li, Y. G. Ma, G. L. Ma

    The particle spectra and Hanbury-Brown Twiss (HBT) radius of Au+Au collisions at RHIC energy are investigated by a hydrodynamical expanding source with both shear and bulk viscosities ($ζ$). With a large width of the ratio of $ζ$ to entropy density $s$, both the particle transverse momentum spectra and the ratio $R_{out}/R_{side}$ of HBT radii in the directi

  58. Victor Berezin

    The model is built in which the main global properties of classical and quasi-classical black holes become local. These are the event horizon, &#34;no-hair&#34;, temperature and entropy. Our construction is based on the features of a quantum collapse, discovered while studying some quantum black hole models. But it is purely classical, and this allows to use

  59. M. Czakon

    We briefly review the recent progress in the study of higher order corrections to hadron scattering processes involving top quark pairs in the final state. In particular, we discuss the Monte-Carlo simulation of the $pp \to t \bar{t} b \bar{b}$ process at the next-to-leading order with the help of the {\tt Helac-NLO} system, and the status of the soft-gluon

  60. Y. Fu, D. Q. Fang, Y. G. Ma, X. Z. Cai

    The fragment production cross sections for 140 MeV/nucleon $^{48,40}$Ca$+^{9}$Be reactions have been calculated by the Heavy Ion Phase Space Exploration (HIPSE) model. Isoscaling behavior is observed. The isoscaling parameters $α$ and $β$ for both heavy and light fragments from HIPSE model calculations are in good agreement with the experiment data. Studies

  61. Robert J. Papoular, Renaud Papoular

    Graphene, a single infinite, planar, sheet of graphite, has the same dielectric resonances as bulk graphite, but solid state theory indicates that its features are about half as wide. Based on this theory, the dielectric functions of mono- and multi-layer graphenes are deduced and compared with those of terrestrial graphite. The resonance width of an ordered

  62. Raphael Cerf, Francesco Manzo

    We analyze the relaxation time of a ferromagnetic d dimensional growth model on the lattice. The model is characterized by d param- eters which represent the activation energies of a site, depending on the number of occupied nearest neighbours. This model is a natural generalisation of the model studied by Dehghanpour and Schonmann [DS97a], where the activat

  63. S. Moch, U. Langenfeld, P. Uwer

    We discuss the direct determination of the running top-quark mass from measurements of the total cross section of hadronic top-quark pair-production. The theory predictions in the MSbar scheme are very stable under scale variations and show rapid apparent convergence of the perturbative expansion. These features are explained by studying the underlying parto

  64. Bintao Cao, Li Luo

    The character formula of any finite dimensional irreducible module for Lie superalgebra $\mathfrak{osp}(3|2m)$ is obtained in terms of characters of generalized Verma modules.

  65. Suman Majumder, Subir K. Das

    We quantify the effect of system size in the kinetics of domain growth in Ising model with 50:50 composition in two spatial dimensions. Our estimate of the exponent, $α=0.334\pm0.004$, for the power law growth of linear domain size, from Monte Carlo simulation using small systems of linear dimensions L=16, 32, 64, and 128, is in excellent agreement with the

  66. Andrea Lucchini, Attila Maroti

    We describe all possible ways how a ring can be expressed as the union of three of its proper subrings. This is an analogue for rings of a 1926 theorem of Scorza about groups. We then determine the minimal number of proper subrings of the simple matrix ring $M_{n}(q)$ whose union is $M_{n}(q)$.

  67. J. -F. Mercure

    Highly correlated electron materials are systems in which many new states of matter can emerge. A particular situation which favours the formation of exotic phases of the electron liquid in complex materials is that where a quantum critical point (QCP) is present the phase diagram. Neighbouring regions in parameter space reveal unusual physical properties, d

  68. Elsen Veli Veliev, Gulsah Kaya

    In the present work, we assume D_{s0}(2317) meson as the c\bar{s} state and study its parameters at finite temperature using QCD sum rules. It is calculated the annihilation and scattering parts of spectral function in the lowest order of perturbation theory. Taking into account perturbative two-loop order α_{s} corrections and nonperturbative corrections up

  69. N. A. Gromov

    The quantum analogs of the N-dimensional Cayley-Klein spaces with different combinations of quantum and Cayley-Klein structures are described for non-minimal multipliers, which include the first and the second powers of contraction parameters in the transformation of deformation parameter. The noncommutative analogs of (N-1)-dimensional constant curvature sp

  70. Guenter Last, Mathew D. Penrose

    We consider a Poisson process $η$ on a measurable space $(\BY,\mathcal{Y})$ equipped with a partial ordering, assumed to be strict almost everwhwere with respect to the intensity measure $λ$ of $η$. We give a Clark-Ocone type formula providing an explicit representation of square integrable martingales (defined with respect to the natural filtration associat

  71. Caleb J. O&#39;Loan

    A quantum channel is a mapping which sends density matrices to density matrices. The estimation of quantum channels is of great importance to the field of quantum information. In this thesis two topics related to estimation of quantum channels are investigated. The first of these is the upper bound of Sarovar and Milburn (2006) on the Fisher information obta

  72. Andreas Nyffeler

    We review recent developments concerning the hadronic light-by-light scattering contribution to the anomalous magnetic moment of the muon. We first discuss why fully off-shell hadronic form factors should be used for the evaluation of this contribution to the g-2. We then reevaluate the numerically dominant pion-exchange contribution in the framework of larg

  73. M. B. N. Kouwenhoven, S. P. Goodwin, Richard J. Parker, M. B. Davies

    Over the past few decades, numerous wide (>1000 au) binaries in the Galactic field and halo have been discovered. Their existence cannot be explained by the process of star formation or by dynamical interactions in the field, and their origin has long been a mystery. We explain the origin of these wide binaries by formation during the dissolution phase of yo

  74. Giancarlo Ferrera

    We present a fully-exclusive next-to-next-to-leading order (NNLO) QCD calculation for vector boson production in hadron-hadron collisions. The calculation is implemented in a parton level Monte Carlo program, which includes the gamma-Z interference, finite-width effects, the leptonic decay of the vector bosons and the corresponding spin correlations. The cod

  75. David Colver

    Various techniques for developing spreadsheet models greatly improve the chance that the end result will not contain basic mechanical errors. However, for every discipline in which a given technique is useful, there is likely to be another in which the same technique works badly. As a result, the author urges that EuSpRIG does not succumb to internal or exte

  76. V. O. Nesterenko, J. Kvasil, P. Vesely, W. Kleinig

    Despite a great success of the Skyrme mean-field approach in exploration of nuclear dynamics, it seems to fail in description of the spin-flip M1 giant resonance. The results for different Skyrme parameterizations are contradictory and poorly agree with experiment. In particular, there is no parameterization which simultaneously describes the one-peak gross

  77. Hans-Thomas Elze

    A new kind of duality between the deep structures of spacetime and matter is proposed here, considering two partial orders which incorporate causality, extensity, and discreteness. This may have surprising consequences for the emergence of quantum mechanics, which are discussed.

  78. M. Podgorski, M. Ribordy

    The GZK neutrino flux characterization would give insights into cosmological source evolution, source spectra and composition at injection from the partial recovery of the degraded information carried by the ultra high energy cosmic rays. The flux is expected to be at levels necessitating a much larger instrumented volume ($>$100 km$^3$) than those currently

  79. Basavaraj S. Devaramani, Ramaswamy Y. S., Babu A. Manjasetty, Gopalakrishna T. R. Nair

    Nanotechnology has already made indelible dents in the fields of communication, computation, electronics, photonics, gas sensors, diagnostic technologies, catalysis, drug delivery systems and imaging. In particular, ZnO nanostructures have attracted a lot of research interest due to their unique structure- and size-dependent electrical, optical, and mechanic

  80. S. McEndoo, S. Croke, J. Brophy, Th. Busch

    Adiabatic techniques using multi-level systems have recently been generalised from the optical case to settings in atom optics, solid state and even classical electrodynamics. The most well known example of these is the so called STIRAP process, which allows transfer of a particle between different states with large fidelity. Here we generalise and examine t

  81. Tanja Branz, Thomas Gutsche, Valery E. Lyubovitskij

    In the present article we report on evidence for hadronic molecule structures in the charmonium sector. In particular we discuss the Y(3940) and the recently observed Y(4140) as heavy hadron molecule states with quantum numbers $J^{PC} = 0^{++}$ or $2^{++}$. The Y(3940) state is considered to be a superposition of $D^{\ast +}D^{\ast -}$ and $D^{\ast 0} \over

  82. N. Bartolo, S. Matarrese, A. Riotto

    We review in a pedagogical way the present status of the impact of non-Gaussianity (NG) on the Cosmic Microwave Background (CMB) anisotropies. We first show how to set the initial conditions at second-order for the (gauge invariant) CMB anisotropies when some primordial NG is present. However, there are many sources of NG in CMB anisotropies, beyond the prim

  83. U. D. Jentschura

    We consider the general scenario of an excited level |i> of a quantum system that can decay via two channels: (i) via a single-quantum jump to an intermediate, resonant level |bar m>, followed by a second single-quantum jump to a final level |f>, and (ii) via a two-quantum transition to a final level |f>. Cascade processes |i> -> |bar m> -> | f> and two-quan

  84. Graeme Watt

    The parton distribution functions (PDFs) are a non-negotiable input to almost all theory predictions at hadron colliders. In this talk, I introduce PDF determination by global analysis and discuss selected topics concerning recent relevant data from HERA and the Tevatron, before giving some prospects for the LHC. The combination of H1 and ZEUS cross sections

  85. A. S. Sheremet, O. S. Mishina, E. Giacobino, D. V. Kupriyanov

    We consider the coherent stimulated Raman process developing in an optically dense and disordered atomic medium in application to the quantum memory scheme. Our theoretical model predicts that the hyperfine interaction in the excited state of alkali atoms can positively affect on the quantum memory efficiency. Based on the concept of the coherent information

  86. P. Delplace, G. Montambaux

    The spectrum of tight binding electrons on a square lattice with half a magnetic flux quantum per unit cell exhibits two Dirac points at the band center. We show that, in the presence of an additional uniaxial staggered potential, this pair of Dirac points may merge into a single one, with a topological transition towards a gapped phase. At the transition, t

  87. L. Jin, Z. Song

    We explore an alternative way of finding the link between a PT non-Hermitian Hamiltonian and a Hermitian one. Based on the analysis of the scattering problem for an imaginary potential and its time reversal process, it is shown that any real-energy eigenstate of a PT tight-binding lattice with on-site imaginary potentials shares the same wave function with a

  88. B. Ruzicka, L. Zulian, E. Zaccarelli, R. Angelini

    Using experiments, theory and simulations, we show that the arrested state observed in a colloidal clay at intermediate concentrations is stabilized by the screened Coulomb repulsion (Wigner glass). Dilution experiments allow us to distinguish this high-concentration disconnected state, which melts upon addition of water, from a low-concentration gel state,

  89. T. Marrodan Undagoitia, F. von Feilitzsch, L. Oberauer, W. Potzel

    Emission spectra of several organic liquid-scintillator mixtures which are relevant for the proposed LENA detector have been measured by exciting the medium with electrons of ~10keV. The results are compared with spectra resulting from ultraviolet light excitation. Good agreement between spectra measured by both methods has been found.

  90. Roman Schubert, Holger Waalkens, Arseni Goussev, Stephen Wiggins

    Transition State Theory forms the basis of computing reaction rates in chemical and other systems. Recently it has been shown how transition state theory can rigorously be realized in phase space using an explicit algorithm. The quantization has been demonstrated to lead to an efficient procedure to compute cumulative reaction probabilities and the associate

  91. Sameer M. Ikhdair, Ramazan Sever

    We study the effect of spatially dependent mass function over the solution of the Dirac equation with the Coulomb potential in the (3+1)-dimensions for any arbitrary spin-orbit $κ$ state$.$ In the framework of the spin and pseudospin symmetry concept, the analytic bound state energy eigenvalues and the corresponding upper and lower two-component spinors of t

  92. Bayram Akarsu

    It has been more than a century since first Lorentz and later Einstein explored relativistic events and still important consequences of that remains unclear to everybody. The present study extensively focus on Lorentz (Length) contraction phenomenon and takes a different approaches to explain how the shrinking of the body appears if exists. We utilized two p

  93. R. S. Farr, M. J. Izzard

    We consider two spherical, roughened crystals with approximately isotropic surface free energy which are brought into contact and begin to sinter. We argue that the geometry immediately post-contact is two dimensional and Cartesian and can be approximated by the evolution of a slot-shaped cavity. On this basis, we construct travelling wave solutions for the

  94. Song Wang, Zhou Fan, Jun Ma, Richard de Grijs

    We present photometry of 104 M31 globular clusters (GCs) and GC candidates in 15 intermediate-band filters of the Beijing-Arizona-Taiwan-Connecticut (BATC) photometric system. The GCs and GC candidates were selected from the Revised Bologna Catalog (v.3.5). We obtain the cluster ages by comparing the photometric data with up-to-date theoretical synthesis mod

  95. Anatoly V. Latyshev, Alexander Yushkanov

    Dielectric permeability of the degenerate electronic gas for the collisional plasmas is found. The kinetic equation of Wigner -- Vlasov -- Boltzmann with integral of collisions in relaxation form in coordinate space is used. We will notice that dielectric permeability with using of the relaxation equation in the momentum space has been received by Mermin.

  96. V. G. Klochkova, V. E. Panchuk, N. S. Tavolganskaya

    Repeated observations with high spectral resolution acquired in 1998-2008 are used to study the temporal behavior of the spectral line profiles and velocity field in the atmosphere and circumstellar envelope of the post-AGB star V448Lac. Asymmetry of the profiles of the strongest absorption lines with low-level excitation potentials less 1eV and time variati

  97. Yoshiyuki Kabashima, Hisanao Takahashi, Osamu Watanabe

    A methodology to analyze the properties of the first (largest) eigenvalue and its eigenvector is developed for large symmetric random sparse matrices utilizing the cavity method of statistical mechanics. Under a tree approximation, which is plausible for infinitely large systems, in conjunction with the introduction of a Lagrange multiplier for constraining

  98. H. C. Kästli

    The CMS pixel detector has been designed for a peak luminosity of 10^34cm-2s-1 and a total dose corresponding to 2 years of LHC operation at a radius of 4 cm from the interaction region. Parts of the pixel detector will have to be replaced until 2015. The detector performance will be degraded for two reasons: radiation damage of the innermost layers and the

  99. H. A. Padmini, A. Keshav Bharadwaj, T. R. Gopalakrishnan Nair

    Development of Curriculum and delivery materials has undergone changes over a period of time, in undergraduate engineering degree system in Indian universities. However, there exists a gap between industry expectations in IT field and skills and knowledge that the graduating engineers possess and this continues to grow. A similar situation has been seen in t

  100. Pierre Hily-Blant, Malcolm Walmsley, G. Pineau Des forêts, David Flower

    We investigated the chemistry of nitrogen--containing species, principally isotopomers of CN, HCN, and HNC, in a sample of pre-protostellar cores. We used the IRAM 30 m telescope to measure the emission in rotational and hyperfine transitions of CN, HCN, 13CN, H13CN, HN13C, and HC15N, in L 1544, L 183, Oph D, L 1517B, L 310. The observations were made along