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December 2007 arXiv papers — page 36

Showing 3,5013,600 of 4,627 papers

  1. Bhaskar Dutta, Yukihiro Mimura, Rabindra Mohapatra

    Discovery of neutrino mass has put the spotlight on supersymmetric SO(10) as a natural candidate for grand unification of forces and matter. However, the suppression of proton decay is a major problem in any supersymmetric grand unified models. In this paper we show how to alleviate this problem by simple threshold effect which raises the colored Higgsino ma

  2. O. Vega, M. S. Clemens, A. Bressan, G. L. Granato

    We fit the near-infrared to radio spectral energy distributions of 30 luminous and ultra-luminous infrared galaxies with pure starburst models or models that include both starburst and AGN components to determine important physical parameters for this population of objects. In particular we constrain the optical depth towards the luminosity source, the star

  3. Jean-Christophe Leyder, Roland Walter, Michalis Lazos, Nicolas Masetti

    Context : A 1000-s flare from a new hard X-ray transient, IGR J08408-4503, was observed by INTEGRAL on May 15, 2006 during the real-time routine monitoring of IBIS/ISGRI images performed at the INTEGRAL Science Data Centre. The flare, detected during a single one-hour long pointing, peaked at 250 mCrab in the 20-40 keV energy range. Aims : Multi-wavelength o

  4. T. C. Rogers

    We outline the basic properties of a pertubative QCD factorization formalism that maintains exact over-all kinematics in both the initial and final states. Such a treatment requires the use of non-perturbative factors that depend on all components of parton four-momentum. These objects are referred to as parton correlation functions. We describe the complica

  5. Shiwei Zhang, D. M. Ceperley

    In 1962, Overhauser showed that within Hartree-Fock (HF) the electron gas is unstable to a spin density wave (SDW) instability. Determining the true HF ground state has remained a challenge. Using numerical calculations for finite systems and analytic techniques, we study the HF ground state of the 3D electron gas. At high density, we find broken spin symmet

  6. C. C. Cheung, L. Stawarz, A. Siemiginowska, D. E Harris

    We describe our efforts to understand large-scale (10's-100's kpc) relativistic jet systems through observations of the highest-redshift quasars. Results from a VLA survey search for radio jets in ~30 z>3.4 quasars are described along with new Chandra observations of 4 selected targets.

  7. Olivier Zendra, Eric Jul, Roland Ducournau, Etienne Gagnon

    ICOOOLPS'2007 was the second edition of the ECOOP-ICOOOLPS workshop. ICOOOLPS intends to bring researchers and practitioners both from academia and industry together, with a spirit of openness, to try and identify and begin to address the numerous and very varied issues of optimization. After a first successful edition, this second one put a stronger emp

  8. Thomas J. Bing, Edward F. Redish

    Symbolic calculators like Mathematica are becoming more commonplace among upper level physics students. The presence of such a powerful calculator can couple strongly to the type of mathematical reasoning students employ. It does not merely offer a convenient way to perform the computations students would have otherwise wanted to do by hand. This paper prese

  9. V. Kurbatov, M. Buescher, S. Dymov, D. Gusev

    The pp -> {pp}_s pi0 differential cross section has been measured with the ANKE spectrometer at COSY-Juelich for seven proton beam energies T_p between 0.5 and 1.97 GeV. By selecting proton pairs with an excitation energy of less than 3 MeV it is ensured that the final {pp}_s system is in the 1S0 state. In the measured region of theta_{pp}^{cm} < 18 deg, the

  10. A. Lobel

    We update the online SpectroWeb database of spectral standard reference stars with 1178 oscillator strength values of atomic absorption lines observed in the optical spectrum of the Sun and Procyon (Alpha CMi A). The updated line oscillator strengths are measured with best fits to the disk-integrated KPNO-FTS spectrum of the Sun observed between 4000 A and 6

  11. George Heald, Tom Oosterloo

    In recent years, it has become clear that large quantities of gas reside in the halos of many spiral galaxies. Whether the presence of this gas is ultimately a consequence of star formation activity in the disk, or accretion from outside of the galaxy, is not yet understood. We present new, deep HI observations of NGC 4395 as part of a continuing observation

  12. Audun Josang

    Belief fusion is the principle of combining separate beliefs or bodies of evidence originating from different sources. Depending on the situation to be modelled, different belief fusion methods can be applied. Cumulative and averaging belief fusion is defined for fusing opinions in subjective logic, and for fusing belief functions in general. The principle o

  13. R. M. Kiehn

    This article examines how the physical presence of field energy and particulate matter can be interpreted in terms of the topological properties of space-time. The theory is developed in terms of vector and matrix equations of exterior differential systems, which are not constrained by tensor diffeomorphic equivalences. The first postulate defines the field

  14. A. Richichi, O. Fors, E. Mason, M. Delbo

    The recent implementation of the high-speed burst mode at the ISAAC instrument on UT1, and its propagation to other ESO instruments, has opened the door to observational capabilities which hold the potential for a wealth of novel results. In the ELT era, when the accent will likely be on lengthy programs aimed at the best sensitivity and angular resolution,

  15. Grigoris Panotopoulos

    The statefinder parameters ($r,s$) in two dark energy models are studied. In the first, we discuss in four-dimensional General Relativity a two fluid model, in which dark energy and dark matter are allowed to interact with each other. In the second model, we consider the DGP brane model generalized by taking a possible energy exchange between the brane and t

  16. Eduardo Esteves

    A curve, that is, a connected, reduced, projective scheme of dimension 1 over an algebraically closed field, admits two types of compactifications of its (generalized) Jacobian: the moduli schemes of P-quasistable torsion-free, rank-1 sheaves and Seshadri&#39;s moduli schemes of S-equivalence classes of semistable torsion-free, rank-1 sheaves. Both are const

  17. HESS Collaboration, F. Aharonian

    The detection of gamma rays in the very-high-energy (VHE) energy range (100 GeV--100 TeV) provides a direct view of the parent population of ultra-relativistic particles found in astrophysical sources. For this reason, VHE gamma rays are useful for understanding the underlying astrophysical processes in non-thermal sources. We investigate unidentified VHE ga

  18. Jean-Philippe Chancelier

    Let $X$ be a real Banach space with a normalized duality mapping uniformly norm-to-weak$^\star$ continuous on bounded sets or a reflexive Banach space which admits a weakly continuous duality mapping $J_Φ$ with gauge $ϕ$. Let $f$ be an {\em $α$-contraction} and $\{T_n\}$ a sequence of nonexpansive mapping, we study the strong convergence of explicit iterativ

  19. Arnaud Le Ny

    These notes have been written to complete a mini-course &#34;Introduction to (generalized) Gibbs measures&#34; given at the universities UFMG (Universidade Federal de Minas Gerais, Belo Horizonte, Brasil) and UFRGS (Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil) during the first semester 2007. The main goal of the lectures was to describe G

  20. Nicolas Ruty, Annemie Van Hirtum, Xavier Pelorson, Avraham Hirschberg

    This paper deals with some of aspects of the influence of asymmetry on vocal folds vibrations. A theoretical model of vocal fold asymmetry is presented. The influence of asymmetry is quantitatively examined in terms of oscillation frequency and pressure threshold. The theoretical model is compared to &#34;in-vitro&#34; experiment on a deformable replica of v

  21. Aram Z. Mekjian

    Analytic expressions are given for the baryonic, electric and strangeness chemical potentials which explicitly show the importance of various terms. Simple scaling relations connecting these chemical potentials are found. Applications to particle ratios and to fluctuations and related thermal properties such as the isothermal compressibility kappaT are illus

  22. Leandro A. J. Marzulo, Felipe M. G. França, Vítor Santos Costa

    The WaveScalar is the first DataFlow Architecture that can efficiently provide the sequential memory semantics required by imperative languages. This work presents an alternative memory ordering mechanism for this architecture, the Transaction WaveCache. Our mechanism maintains the execution order of memory operations within blocks of code, called Waves, but

  23. Michael Galperin, Sergei Tretiak

    We propose a scheme for calculation of linear optical response of current-carrying molecular junctions for the case when electronic tunneling through the junction is much faster than characteristic time of external laser field. We discuss relationships between nonequilibrium Green function (NEGF) and time-dependent density functional theory (TDDFT) approache

  24. H. B. Lau, R. J. Stancliffe, C. A. Tout

    We use the Cambridge stellar evolution code STARS to model the evolution of 5-7 solar mass zero-metallicity stars. With enhanced resolution at the hydrogen and helium burning shell in the AGB phases, we are able to model the entire thermally pulsing asymptotic giant branch (TP-AGB) phase. The helium luminosities of the thermal pulses are significantly lower

  25. M. Pierleoni, A. Maselli, B. Ciardi

    In this paper we present CRASH_alpha, the first radiative transfer code for cosmological application that follows the parallel propagation of Ly_alpha and ionizing photons. CRASH_alpha is a version of the continuum radiative transfer code CRASH with a new algorithm to follow the propagation of Ly_alpha photons through a gas configuration whose ionization str

  26. Jean-Marc Bardet, Imen Kammoun

    The aim of this paper is first the detection of multiple abrupt changes of the long-range dependence (respectively self-similarity, local fractality) parameters from a sample of a Gaussian stationary times series (respectively time series, continuous-time process having stationary increments). The estimator of the $m$ change instants (the number $m$ is suppo

  27. Denis Ullmo

    Experimental progresses in the miniaturisation of electronic devices have made routinely available in the laboratory small electronic systems, on the micron or sub-micron scale, which at low temperature are sufficiently well isolated from their environment to be considered as fully coherent. Some of their most important properties are dominated by the intera

  28. Keiya Shirahama, Keiichi Yamamoto, Yoshiyuki Shibayama

    We have examined superfluid properties of $^4$He confined to a nano-porous Gelsil glass that has nanopores 2.5 nm in diameter. The pressure-temperature phase diagram was determined by torsional oscillator, heat capacity and pressure studies. The superfluid transition temperature $T_{\mathrm c}$ approaches zero at 3.4 MPa, indicating a novel &#34;quantum&#34;

  29. Roman Taranets, Yuliya Namlyeyeva

    We investigate multidimensional model for incompressible non-Newtonian fluids. Using method of energy estimates we prove the property of finite speed of propagations of the solution support for this problem. We find sharp bounds of the propagations by $L^2$--norm and $L^1$--norm of initial data.

  30. A. P. Kobushkin, Ya. D. Krivenko-Emetov

    In the framework of Glauber-Sitenko model we calculate contribution of Coulomb interaction in cross-section of A(d,p) reaction at high energy and zero angle. It is demonstrated that such effect significantly increases the differential cross section only at peak, where the proton momentum $p$ is near half of the deuteron momentum $p_d$ in lab. frame, $p \sim

  31. Nazirah N. Jetha, Martin J. Hardcastle, Arif Babul, Ewan O&#39;Sullivan

    We discuss the effects of energy injection into the intra-group medium of the group of galaxies associated with NGC 741. The X-ray emission reveals a large bubble, which in the absence of a currently bright central radio source, may have been inflated by a previous cycle of nuclear activity . If the bubble is filled with a light, relativistic fluid we calcul

  32. A. V. Zasov, O. V. Abramova

    The thickness of isothermal gaseous layers and their midplane volume densities ρ_{gas}(R) were calculated for several spiral and LSB galaxies by solving the self-consistent equilibrium equations for gaseous discs embedded into a stellar one. The self-gravity of the gas and influence of dark halo on the disk thickness were taken into account. The resulting mi

  33. A. More, J. P. McKean, T. W. B. Muxlow, R. W. Porcas

    The gravitational lens system CLASS B2108+213 has two lensed images separated by 4.56 arcsec. Such a wide image separation suggests that the lens is either a massive galaxy, or is composed of a group of galaxies. To investigate the structure of the lensing potential we have carried out new high resolution imaging of the two lensed images at 1.7 GHz with the

  34. Bence Kocsis, Zoltan Haiman, Kristen Menou

    Electromagnetic (EM) counterparts to supermassive black hole binary mergers observed by LISA can be localized to within the field of view of astronomical instruments ~10 deg^2 hours to weeks prior to coalescence. The temporal coincidence of any prompt EM counterpart with a gravitationally-timed merger may offer the best chance of identifying a unique host ga

  35. Lars Hellström

    This paper gives a generic form of the diamond lemma, which includes support for additive and topological structures of the base set, and which does not require any further structure (e.g. an associative multiplication operation) to be present. This result is intended to be used as the core of diamond lemmas for particular algebraic structures, taking care o

  36. Gani Aldashev, Timoteo Carletti

    We study the dynamics of public opinion in a model in which agents change their opinions as a result of random binary encounters if the opinion difference is below their individual thresholds that evolve over time. We ground these thresholds in a simple individual cost-benefit analysis with linear benefits of diversity and quadratic communication costs. We c

  37. A. Mozeika, A. C. C. Coolen

    We study the stochastic dynamics of Ising spin models with random bonds, interacting on finitely connected Poissonnian random graphs. We use the dynamical replica method to derive closed dynamical equations for the joint spin-field probability distribution, and solve these within the replica symmetry ansatz. Although the theory is developed in a general sett

  38. M. Puech, F. Hammer, H. Flores, Y. Yang

    The Large Program IMAGES is near 2/3 of its completion. It provides us with kinematics (GIRAFFE deployable IFUs), gas chemistry (FORS2), detailed morphologies (HST/ACS) and IR photometry (Spitzer) for a set of 70 galaxies representative of intermediate mass galaxies (MJ<=-20.3 or 1.5e10 Mo) at z=0.4-0.75. We discover that, 6 Gyr ago, a significant fraction o

  39. Vladimir A. Mikhailets, Alexandr A. Murach

    The interpolation of couples of separable Hilbert spaces with a function parameter is studied. The main properties of the classic interpolation are proved. Some applications to the interpolation of isotropic Hörmander spaces over a closed manifold are given.

  40. F. Frontera, G. Loffredo, A. Pisa, L. Milani

    We report the status of the HAXTEL project, devoted to perform a design study and the development of a Laue lens prototype. After a summary of the major results of the design study, the approach adopted to develop a Demonstration Model of a Laue lens is discussed, the set up described, and some results presented.

  41. Jakub Jȩdrak

    We consider a simple model of the dynamics of a single electron in a crystal lattice. Although this is a standard problem in condensed matter physics, alternative ways of evaluating a partition function for such a system lead to equalities, that may be interesting from the point of view of mathematical analysis, combinatorics and graph theory.

  42. Carlos Barcelo, Stefano Liberati, Sebastiano Sonego, Matt Visser

    While the outcome of gravitational collapse in classical general relativity is unquestionably a black hole, up to now no full and complete semiclassical description of black hole formation has been thoroughly investigated. Here we revisit the standard scenario for this process. By analyzing how semiclassical collapse proceeds we show that the very formation

  43. D. N. Basu, Tapan Mukhopadhyay

    Some useful kinematical relations for the absorption of a photon by a nucleus and its recoil are derived for the relativistic incident energies. These expressions provided for the relativistic kinematics of photoabsorption reactions, though simple, will be immensely useful for experimentalists as well as theoreticians.

  44. J. Carvalho, N. Castro, L. Chikovani, T. Djobava

    The ATLAS experiment sensitivity to top quark Flavour Changing Neutral Current (FCNC) decays was studied at LHC using ttbar events. While one of the top quarks is expected to follow the dominant Standard Model decay t->bW, the other decays through a FCNC channel, i.e. t-> Z u(c), t-> gamma u(c) or t-> g u(c). Different types of analyses, applied to each FCNC

  45. Ricard V. Sole

    Although the conscious state is considered an emergent property of the underlying brain activity and thus somehow resides on brain hardware, there is a non-univocal mapping between both. Given a neural hardware, multiple conscious patterns are consistent with it. Here we show, by means of a simple {\em gedankenexperiment} that this has an important logic con

  46. M. Dovciak, V. Karas, G. Matt, R. W. Goosmann

    We study light curves and spectra (equivalent widths of the iron line and some other spectral characteristics) which arise by reprocessing on the surface of an accretion disc, following its illumination by a primary off-axis source - an X-ray &#39;flare&#39;, assumed to be a point-like source just above the accretion disc. We consider all general relativity

  47. Haiyan Wu, Ming Yuan, Susan M. Kaech, M. Elizabeth Halloran

    CD8 T cells are specialized immune cells that play an important role in the regulation of antiviral immune response and the generation of protective immunity. In this paper we investigate the differentiation of memory CD8 T cells in the immune response using a short time course microarray experiment. Structurally, this experiment is similar to many in that i

  48. Daniel Wilczak, Piotr Zgliczynski

    The goal of this paper is to show how to produce a piece of rigorous bifurcation diagram of periodic orbits for an ODE. We study the Rossler system, one of the textbook examples of ODEs generating nontrivial dynamics, for the parameter range containing two period doubling bifurcations.

  49. M. Dovciak, V. Karas, G. Matt, R. W. Goosmann

    We study light curves and spectra (equivalent widths of the iron line and some other spectral characteristics) which arise by reflection on the surface of an accretion disc, following its illumination by a primary off-axis source - an X-ray &#39;flare&#39;, assumed to be a point-like source just above the accretion disc resulting in a spot with radius dr/r<1

  50. Christian Holm Christensen, Jens Jorgen Gaardhoje, Kristjan Gulbrandsen, Borge Svane Nielsen

    The ALICE Forward Multiplicity Detector (FMD) is a silicon strip detector with 51,200 strips arranged in 5 rings, covering the range $-3.4 < η< 5.1$. It is placed around the beam pipe at small angles to extend the charged particle acceptance of ALICE into the forward regions, not covered by the central barrel detectors.

  51. P. Patie

    We first introduce and derive some basic properties of a two-parameters family of one-sided Levy processes. Their Laplace exponents are given in terms of the Pochhammer symbol. This family includes, in a limit case, the family of Brownian motion with drifts. Then, we proceed by computing the density of the law of the exponential functional associated to some

  52. Dariusz Chruscinski, Andrzej Kossakowski

    We present very simple method for constructing indecomposable entanglement witnesses out of a given pair -- an entanglement witness W and the corresponding state detected by W. This method may be used to produce new classes of atomic witnesses which are able to detect the `weakest&#39; quantum entanglement. Actually, it works perfectly in the multipartite ca

  53. L. E. Marcucci, L. Girlanda, A. Kievsky, S. Rosati

    The structure of A=3 low-energy scattering states is described using the hyperspherical harmonics method with realistic Hamiltonian models, consisting of two- and three-nucleon interactions. Both coordinate and momentum space two-nucleon potential models are considered.

  54. Art B. Owen

    Recently there has been much interest in data that, in statistical language, may be described as having a large crossed and severely unbalanced random effects structure. Such data sets arise for recommender engines and information retrieval problems. Many large bipartite weighted graphs have this structure too. We would like to assess the stability of algori

  55. Henrik Beuther

    This article presents recent work to constrain the physical and chemical properties in high-mass star formation based largely on interferometric high-spatial-resolution continuum and spectral line studies at (sub)mm wavelengths. After outlining the concepts, potential observational tests, a proposed evolutionary sequence and different possible definitions fo

  56. Giovanni Vladilo, Jason X. Prochaska, Arthur M. Wolfe

    We analyzed the spectroscopic and photometric database of the 5th data release of the Sloan Digital Sky Survey (SDSS) to search for evidence of the quasar reddening produced by dust embedded in intervening damped Ly alpha (DLA) systems. From a list of 5164 quasars in the interval of emission redshift 2.25 </= z_e </= 3.5 and SDSS spectra with signal-to-noise

  57. Ilya D. Feranchuk, Sergey I. Feranchuk

    The self-localized quasi-particle excitation of the electron-positron field (EPF) is found for the first time in the framework of a standard form of the quantum electrodynamics. This state is interpreted as the ``physical'' electron (positron) and it allows one to solve the following problems: i) to express the ``primary'' charge $e_0$ and the mass $m_0$ of

  58. Amy Berrington de González, D. R. Cox

    Several different types of statistical interaction are defined and distinguished, primarily on the basis of the nature of the factors defining the interaction. Illustrative examples, mostly epidemiological, are given. The emphasis is primarily on interpretation rather than on methods for detecting interactions.

  59. Richard G. Lyon, Sally Heap, Amy Lo, Webster Cash

    A multitude of coronagraphic techniques for the space-based direct detection and characterization of exo-solar terrestrial planets are actively being pursued by the astronomical community. Typical coronagraphs have internal shaped focal plane and/or pupil plane occulting masks which block and/or diffract starlight thereby increasing the planet&#39;s contrast

  60. J. Bellazzini, V. Benci, C. Bonanno, A. M. Micheletti

    In this paper we study existence and orbital stability for solitary waves of the nonlinear Klein-Gordon equation. The energy of these solutions travels as a localized packet, hence they are a particular type of solitons. In particular we are interested in sufficient conditions on the potential for the existence of solitons. Our proof is based on the study of

  61. I. Fachruddin, I. Abdulrahman

    Scattering of 2 particles of spin 0 and 1/2 is evaluated based on a basis constructed from the momentum and the helicity states (the momentum-helicity basis). This shortly called three-dimensional (3D) technique is a good alternative to the standard partial wave (PW) technique especially for higher energies, where PW calculations may become not feasible. Tak

  62. Gary Steigman

    Primordial nucleosynthesis provides a probe of the Universe during its early evolution. Given the progress exploring the constituents, structure, and recent evolution of the Universe, it is timely to review the status of Big Bang Nucleosynthesis (BBN) and to confront its predictions, along with the constraints which emerge from them, with those derived from

  63. Bruce S. Weir

    It is now widely accepted that forensic DNA profiles are rare, so it was a surprise to some people that different people represented in offender databases are being found to have the same profile. In the first place this is just an illustration of the birthday problem, but a deeper analysis must take into account dependencies among profiles caused by family

  64. Steven Duplij, Illia Shapoval

    Basic concepts of quantum theory of information, principles of quantum calculations and the possibility of creation on this basis unique on calculation power and functioning principle device, named quantum computer, are briefly reviewed. The main blocks of quantum logic, schemes of implementation of quantum calculations, as well as some known today effective

  65. Joao Marques-Silva, Jordi Planes

    Maximum Satisfiability (MaxSAT) is a well-known optimization pro- blem, with several practical applications. The most widely known MAXS AT algorithms are ineffective at solving hard problems instances from practical application domains. Recent work proposed using efficient Boolean Satisfiability (SAT) solvers for solving the MaxSAT problem, based on identify

  66. Bongsoo Kim, Kyozi Kawasaki

    We develop a field theoretical treatment of a model of interacting Brownian particles. We pay particular attention to the requirement of the time reversal invariance and the fluctuation-dissipation relationship (FDR). The method used is a modified version of the auxiliary field method due originally to Andreanov, Biroli and Lefevre [J. Stat. Mech. P07008 (20

  67. R. Nirmala, Darshan C. Kundaliya, A. V. Morozkin, S. K. Malik

    Heat capacity of polycrystalline R2Ti3Ge4 (R = Gd, Tb and Er) compounds (Orthorhombic, Sm5Ge4-type, Space group Pnma) has been studied in the temperature range of 1.8 K to 300 K in various applied magnetic fields. The compounds with magnetic lanthanide elements show interesting low field magnetism intrigued by possible presence of competing antiferromagnetic

  68. B. Ziaja, H. Wabnitz, E. Weckert, T. Möller

    Non-equilibrium processes following the irradiation of atomic clusters with short pulses of vacuum ultraviolet radiation are modelled using kinetic Boltzmann equations. The dependence of the ionization dynamics on the cluster size is investigated. The predictions on: (i) the maximal and average ion charge created, (ii) ion charge state distribution, (iii) av

  69. Jungmin Choi, Kyounghee Kim

    The distribution of a time integral of geometric Brownian motion is not well understood. To price an Asian option and to obtain measures of its dependence on the parameters of time, strike price, and underlying market price, it is essential to have the distribution of time integral of geometric Brownian motion and it is also required to have a way to manipul

  70. L. Meier, G. Salis, E. Gini, I. Shorubalko

    We report on spatially resolved measurements of the spin-orbit effective magnetic field in a GaAs/InGaAs quantum-well. Biased gate electrodes lead to an electric-field distribution in which the quantum-well electrons move according to the local orientation and magnitude of the electric field. This motion induces Rashba and Dresselhaus effective magnetic fiel

  71. Diego Cordoba, Francisco Gancedo

    We consider the fluid interface problem given by two incompressible fluids with different densities evolving by Darcy&#39;s law. This scenario is known as the Muskat problem for fluids with the same viscosities, being in two dimensions mathematically analogous to the two-phase Hele-Shaw cell. We prove in the stable case (the denser fluid is below) a maximum

  72. Ibrar Hussain, Fazal M. Mahomed, Asghar Qadir

    Following the use of approximate symmetries for the Schwarzschild spacetime by A.H. Kara, F.M. Mahomed and A. Qadir (Nonlinear Dynam., to appear), we have investigated the exact and approximate symmetries of the system of geodesic equations for the Reissner-Nordstr\"om spacetime (RN). For this purpose we are forced to use second order approximate symmetries.

  73. Valerij Gurin

    A series of endofullerenes Ag@C60 with different symmetry are calculated at ab initio level. The lowest energy structure is completely asymmetrical one (C1), in which the endo-atom has noticeably off-centre position. The symmetrical structures are less stable. Silver atom in the Ag@C60 (C1) endofullerene has the low negative charge and high spin density.

  74. Shizeng Lin, Bo Zheng

    We report Monte Carlo simulations of critical dynamics far from equilibrium on a perfect and non-perfect surface in the 3d Ising model. For an ordered initial state, the dynamic relaxation of the surface magnetization, the line magnetization of the defect line, and the corresponding susceptibilities and appropriate cumulant is carefully examined at the ordin

  75. Yihong Hu, Daoli Zhu, Yang Li, Bing Su

    Inspired by studies on airline networks we propose a general model for weighted networks in which topological growth and weight dynamics are both determined by cost adversarial mechanism. Since transportation networks are designed and operated with objectives to reduce cost, the theory of cost in micro-economics plays a critical role in the evolution. We ass

  76. S. Ray, N. S. Pattabiraman, Krishichayan, A. Chakraborty

    High spin states in $^{103}$Ag were investigated with the Gammasphere array, using the $^{72}$Ge($^{35}$Cl,$2p2n$)$^{103}$Ag reaction at an incident beam energy of 135 MeV. A $ΔJ$=1 sequence with predominantly magnetic transitions and two nearly-degenerate $ΔJ=1$ doublet bands have been observed. The dipole band shows a decreasing trend in the $B(M1)$ streng

  77. M. D. Stewart, Aijun Yin, J. M. Xu, J. M. Valles

    We have observed multiple magnetic field driven superconductor to insulator transitions (SIT) in amorphous Bi films perforated with a nano-honeycomb (NHC) array of holes. The period of the magneto-resistance, H=H_M=h/2eS where S is the area of a unit cell of holes, indicates the field driven transitions are boson dominated. The field-dependent resistance fol

  78. L. D. Paniak, P. M. Charland

    We propose a new starting point for comparing dose distributions in therapeutic radiation physics using a Jacobian-based measure. The measure is normalization independent, free of tunable parameters, bounded and converges to a unique value when comparing unrelated dose distributions. We present a preliminary demonstration of the sensitivity and general chara

  79. I. D. Shkredov

    In the paper we are studying some properties of subsets Q of sums of dissociated sets. The exact upper bound for the number of solutions of the following equation (1) q_1 + ... + q_p = q_{p+1} + ... + q_{2p}, q_i \in Q in groups F_2^n is found. Using our approach, we easily prove a recent result of J. Bourgain on sets of large exponential sums and obtain a t

  80. Zejun Hu, Haizhong Li, Luc Vrancken

    There exists a well known construction which allows to associate with two hyperbolic affine spheres $f_i: M_i^{n_i} \to \mathbb R^{n_i+1}$ a new hyperbolic affine sphere immersion of $I \times M_1 \times M_2$ into $\mathbb R^{n_1+n_2+3}$. In this paper we deal with the inverse problem: how to determine from properties of the difference tensor whether a given

  81. Xue-juan Yang, Fang-jun Lu, Li Chen

    We present high spatial resolution X-ray spectroscopy of supernova remnant Cassiopeia A with the {\sl Chandra} observations. The X-ray emitting region of this remnant was divided into 38 $\times$ 34 pixels with a scale of 10$\arcsec$ $\times$ 10$\arcsec$ each. Spectra of 960 pixels were created and fitted with an absorbed two component non-equilibrium ioniza

  82. Kun Lü, Jing-Dong Bao

    Anomalous transport of a particle subjected to non-Ohmic damping of the power $δ$ in a tilted periodic potential is investigated via Monte Carlo simulation of generalized Langevin equation. It is found that the system exhibits two relative motion modes: the locking state and the running state. Under the surrounding of sub-Ohmic damping ($0<δ<1$), the particl

  83. Jonathan A. Hillman

    We consider the homotopy types of $PD_4$-complexes $X$ with fundamental group $π$ such that $c.d.π=2$ and $π$ has one end. Let $β=β_2(π;F_2)$ and $w=w_1(X)$. Our main result is that (modulo two technical conditions on $(π,w)$) there are at most $2^β$ orbits of $k$-invariants determining &#34;strongly minimal&#34; complexes (i.e., those with homotopy intersec

  84. Motomichi Tashiro

    The spin-exchange effect in spin-polarized electron collisions with unpolarized open-shell molecules, O$_2$, B$_2$, S$_2$ and Si$_2$, has been studied by the R-matrix method with the fixed-bond approximation. All of these molecules have ${}^3 Σ_{g}^{-}$ symmetry in their ground states. Usual integrated cross sections with unpolarized electrons has also been

  85. C. E. Senkbeil, S. P. Ellingsen, J. E. J. Lovell, J. -P. Macquart

    We present observations of a rare, rapid, high amplitude Extreme Scattering Event toward the compact BL-Lac AO 0235+164 at 6.65 GHz. The ESE cloud is compact; we estimate its diameter between 0.09 and 0.9 AU, and is at a distance of less than 3.6 kpc. Limits on the angular extent of the ESE cloud imply a minimum cloud electron density of ~ 4 x 10^3 cm^-3. Ba

  86. Graeme W. Milton, Pierre Seppecher

    We give a complete characterization of the possible response matrices at a fixed frequency of n-terminal electrical networks of inductors, capacitors, resistors and grounds, and of n-terminal discrete linear elastodynamic networks of springs and point masses, both in the three-dimensional case and in the two-dimensional case. Specifically we construct networ

  87. Zhendong Wang, Sumit Mazumdar, Alok Shukla

    We develop a theory of the electronic structure and photophysics of interacting chains of $π$-conjugated polymers to understand the differences between solutions and films. While photoexcitation generates only the exciton in solutions, the optical exciton as well as weakly allowed excimers are generated in films. Photoinduced absorption in films is primarily

  88. Kaushik Mitra, C. J. Lobb, C. A. R. Sá de Melo

    We study decoherence effects in a dc SQUID phase qubit caused by an isolation circuit with a resonant frequency. The coupling between the SQUID phase qubit and its environment is modeled via the Caldeira-Leggett formulation of quantum dissipation/coherence, where the spectral density of the environment is related to the admittance of the isolation circuit. W

  89. Piet W. Brouwer, Joern N. Kupferschmidt

    In disordered metals, electron-electron interactions are the origin of a small correction to the conductivity, the &#34;Altshuler-Aronov correction&#34;. Here we investigate the Altshuler-Aronov correction of a conductor in which the electron motion is ballistic and chaotic. We consider the case of a double quantum dot, which is the simplest example of a bal

  90. Jelte T. A. de Jong, Konrad H. Kuijken, Philippe Heraudeau

    Context: Difference imaging has proven to be a powerful technique for detecting and monitoring the variability of unresolved stellar sources in M 31. Using this technique in surveys of galaxies outside the Local Group could have many interesting applications. Aims: The goal of this paper is to test difference imaging photometry on Centaurus A, the nearest gi

  91. Alessandro Bettini

    Underground laboratories provide the low radioactive background environment necessary to explore the highest energy scales that cannot be reached with accelerators, by searching for extremely rare phenomena. I have requested to the Directors of the Laboratories a standard set of questions on the principal characteristics of their laboratory and collected the

  92. Ilarion V. Melnikov, Savdeep Sethi

    We compute correlators of chiral operators in (0,2) supersymmetric Landau-Ginzburg theories. The class of theories and the correlators we study are relevant for extending and testing mirror symmetry away from the (2,2) locus. More generally, these methods provide alpha&#39;-exact results about certain superpotential couplings in compactifications of the hete

  93. Michael Efroimsky

    In geophysics and seismology, it is a common knowledge that the quality factors Q of the mantle and crust materials scale as the tidal frequency to a positive fractional power (Karato 2007, Efroimsky and Lainey 2007). In astronomy, there exists an equally common belief that such rheological models introduce discontinuities into the equations and thus are unr

  94. Jorge Noronha, Giorgio Torrieri, Miklos Gyulassy

    The near zone energy-momentum tensor of a supersonic heavy quark jet moving through a strongly-coupled $\mathcal{N}=4$ SYM plasma is analyzed in terms of first-order Navier-Stokes hydrodynamics. It is shown that the hydrodynamical description of the near quark region worsens with increasing quark velocities. For realistic quark velocities, $v=0.99$, the non-

  95. A. Pawlis, M. Panfilova, D. J. As, K. Lischka

    Excitons bound to flourine atoms in ZnSe have the potential for several quantum optical applications. Examples include optically accessible quantum memories for quantum information processing and lasing without inversion. These applications require the bound-exciton transitions to be coupled to cavities with high cooperativity factors, which results in the e

  96. K. Belczynski, R. O&#39;Shaughnessy, V. Kalogera, F. Rasio

    Mergers of double neutron stars are considered the most likely progenitors for short gamma-ray bursts. Indeed such a merger can produce a black hole with a transient accreting torus of nuclear matter (Lee & Ramirez-Ruiz 2007, Oechslin & Janka 2006), and the conversion of a fraction of the torus mass-energy to radiation can power a gamma-ray burst (Nakar 2006

  97. Alexander Belyaev, Shahida Dar, Ilia Gogoladze, Azar Mustafayev

    We estimate the bounds on Higgs and sparticle masses and discuss their correlations in the constrained minimal supersymmetric standard model (CMSSM). In our analysis we have applied the present constraints from collider and low energy experiments, as well as the experimental bound on cold dark matter from WMAP. For a given lightest Higgs boson mass, which is

  98. Sen Zhou, Ziqiang Wang

    We show that finite angular momentum pairing chiral superconductors on the triangular lattice have point zeroes in the complex gap function. A topological quantum phase transition takes place through a nodal superconducting state at a specific carrier density $x_c$ where the normal state Fermi surface crosses the isolated zeros. For spin singlet pairing, we

  99. Mark T. Lusk, L. D. Carr

    We present a new way of nano-engineering graphene using defect domains. These regions have ring structures that depart from the usual honeycomb lattice, though each carbon atom still has three nearest neighbors. A set of stable domain structures is identified using density functional theory (DFT), including blisters, ridges, ribbons, and metacrystals. All su

  100. C. R. Cowley, S. Hubrig

    The magnetic, chemically peculiar A-star HR 710 (HD 15144, ADS 1849A, AB Cet) has a close companion in a nearly circular orbit. Its 3-day period is unusually short for such stars. The system emits moderately hard x-rays, which likely come from a white dwarf secondary (ADS 1849Ab). The Sr II spectrum is very strong, and the resonance lines show similar core-n