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November 2008 arXiv papers — page 41

Showing 4,0014,100 of 4,899 papers

  1. Nikolaj Bjørner, Andreas Blass, Yuri Gurevich, Madan Musuvathi

    In connection with machine arithmetic, we are interested in systems of constraints of the form x + k \leq y + k'. Over integers, the satisfiability problem for such systems is polynomial time. The problem becomes NP complete if we restrict attention to the residues for a fixed modulus N.

  2. M. Eisterer, J. Emhofer, S. Sorta, M. Zehetmayer

    Current transport in polycrystalline magnesium diboride is highly non-uniform (percolative) due to the presence of secondary phases and also due to the intrinsic anisotropy of the material. The influence of secondary phases on the transport properties of MgB2 was investigated. Bulk samples were prepared from a mixture of MgB2 and MgO powders by the ex-situ t

  3. Christian Corda

    After a brief review of the work of de Paula, Miranda and Marinho on massive gravitational waves arising from a bimetric theory of gravity, in this paper it is shown that the presence of the mass generates a longi- tudinal component in a particular polarization of the wave. The effect of this polarization on test masses is performed using the geodesic deviat

  4. H. de Sandes, R. Rosenfeld

    Models of warped extra dimensions with custodial symmetry usually predict the existence of a light Kaluza-Klein fermion arising as a partner of the right-handed top quark, sometimes called light custodians which we will denote $\tilde{b}_R$. The production of these particles at the LHC can give rise to multi-W events which could be observed in same-sign dile

  5. J. A. Zurita Heras, R. Walter

    AX J1845.0-0433 is a transient high-mass X-ray binary discovered by ASCA. The source displays bright and short flares observed recently with INTEGRAL. The transient behaviour and the bright and short flares are studied in order to understand the accretion mechanisms and the nature of the source. Public INTEGRAL data and a pointed XMM-Newton observation are u

  6. M. Mohsenzadeh, S. Rouhani, M. V. Takook

    The power spectrum of scalar field and space-time metric perturbations produced in the process of inflation of universe, have been presented in this paper by an alternative approach to field quantization namely, Krein space quantization [1,2]. Auxiliary negative norm states, the modes of which do not interact with the physical world, have been utilized in th

  7. Thimo Rohlf, Stefan Bornholdt

    It has been proposed that adaptation in complex systems is optimized at the critical boundary between ordered and disordered dynamical regimes. Here, we review models of evolving dynamical networks that lead to self-organization of network topology based on a local coupling between a dynamical order parameter and rewiring of network connectivity, with conver

  8. P. Bianchi, M. Debbah, J. Najim

    Consider a $n \times n$ matrix from the Gaussian Unitary Ensemble (GUE). Given a finite collection of bounded disjoint real Borel sets $(Δ_{i,n},\ 1\leq i\leq p)$, properly rescaled, and eventually included in any neighbourhood of the support of Wigner's semi-circle law, we prove that the related counting measures $({\mathcal N}_n(Δ_{i,n}), 1\leq i\leq p

  9. V. Bosch-Ramon

    LS 5039 is an X-ray binary that presents non-thermal radio emission. The radiation at $\sim 5$ GHz is quite steady and optically thin, consisting on a dominant core plus an extended jet-like structure. There is a spectral turnover around 1 GHz, and evidence of variability at timescales of 1 yr at 234 MHz. We investigate the radio emitter properties using the

  10. Andreas Blass, Yuri Gurevich

    A natural liberalization of Datalog is used in the Distributed Knowledge Authorization Language (DKAL). We show that the expressive power of this liberal Datalog is that of existential fixed-point logic. The exposition is self-contained.

  11. Carsten Müller

    The creation of lepton pairs ($e^+e^-$ and $μ^+μ^-$) via multiphoton absorption in collisions of ultrarelativistic ion beams with ultrashort high-frequency laser pulses is considered. Both the free and the bound-free production channels are addressed, where in the latter case the negatively charged lepton is created in a bound atomic state. It is shown that

  12. S. E. Shaw, A. B. Hill, E. Kuulkers, S. Brandt

    The timing properties of the 4.45 s pulsar in the Be X-ray binary system GRO J1750-27 are examined using hard X-ray data from INTEGRAL and Swift during a Type II outburst observed during 2008. The orbital parameters of the system are measured and agree well with those found during the last known outburst of the system in 1995. Correcting the effects of the d

  13. S. N. Gninenko, N. V. Krasnikov, V. A. Matveev

    A class of extra dimensional models with a warped metric predict tunneling of a massive particle localized on our brane and escaping into additional dimensions. The experimental signature of this effect is the disappearance of the particle from our world, i.e. the particle $\to invisible$ decay. We point out that measurements of $Z\prime \to invisible$ decay

  14. Peter Talkner, Michele Campisi, Peter Hänggi

    The characteristic function for the joint measurement of the changes of two commuting observables upon an external forcing of a quantum system is derived. In particular, the statistics of the internal energy, the exchanged heat and the work of a quantum system that {\it weakly} couples to its environment is determined in terms of the energy changes of the sy

  15. M. Lombardo, J. Zeman, M. Sejnoha, G. Falsone

    The purpose of this study is to explore three numerical approaches to the elastic homogenization of disordered masonry structures with moderate meso/macro-lengthscale ratio. The methods investigated include a representative of perturbation methods, the Karhunen-Loève expansion technique coupled with Monte-Carlo simulations and a solver based on the Hashin-Sh

  16. Aurélie Bertaux, AGNès Braud, Florence Le Ber

    We have used Galois lattices for mining hydrobiological data. These data are about macrophytes, that are macroscopic plants living in water bodies. These plants are characterized by several biological traits, that own several modalities. Our aim is to cluster the plants according to their common traits and modalities and to find out the relations between tra

  17. Y. S. Kim

    One hundred years ago, in 1908, Hermann Minkowski completed his proof that Maxwell's equations are covariant under Lorentz transformations. During this process, he introduced a four-dimensional space called the Minkowskian space. In 1949, P. A. M. Dirac showed the Minkowskian space can be handled with the light-cone coordinate system with squeeze transfo

  18. P C Ingrey, K I Hopcraft, E Jakeman, O E French

    We report analytical calculations for the propagation of electromagnetic radiation through an inhomogeneous layer whose refractive index varies in one dimension situated between bulk right- and left-handed media. Significant field localization is generated in the layer that is caused by the coherent superposition of evanescent waves. The strength of the fiel

  19. S. Gardner

    A Faraday rotation experiment can set limits on the magnetic moment of a electrically-neutral, dark-matter particle, and the limits increase in stringency as the candidate-particle mass decreases. Consequently, if we assume the dark-matter particle to be a thermal relic, our most stringent constraints emerge at the keV mass scale. We discuss how such an expe

  20. Andreas Blass, Yuri Gurevich

    Existential fixed point logic (EFPL) is a natural fit for some applications, and the purpose of this talk is to attract attention to EFPL. The logic is also interesting in its own right as it has attractive properties. One of those properties is rather unusual: truth of formulas can be defined (given appropriate syntactic apparatus) in the logic. We mentione

  21. Guangbin Ren, Liang Liu

    Assume that $f$ is Dunkl polyharmonic in $\mathbb{R}^n$ (i.e. $(Δ_h)^p f=0$ for some integer $p$, where $Δ_h$ is the Dunkl Laplacian associated to a root system $R$ and to a multiplicity function $κ$, defined on $R$ and invariant with respect to the finite Coxeter group). Necessary and successful condition that $f$ is a polynomial of degree $\le s$ for $s\ge

  22. Alastair L Windus, Henrik Jeldtoft Jensen

    We re-examine a population model which exhibits a continuous absorbing phase transition which belongs to directed percolation in 1+1 dimensions and a first order transition in 2+1 dimensions and above. Studying the model on fractal lattices, we examine at what fractal dimension 1<d_f<2, the change in order occurs. As well as commenting on the order of the tr

  23. Nathanial P. Brown, Alin Ciuperca

    It is shown that if A is a stably finite C*-algebra and E is a countably generated Hilbert A-module, then E gives rise to a compact element of the Cuntz semigroup if and only if E is algebraically finitely generated and projective. It follows that if E and F are equivalent in the sense of Coward, Elliott and Ivanescu (CEI) and E is algebraically finitely gen

  24. Bernhard Rothenstein

    We show that alternative relativity theories that are essentially based on varied distant clock synchronization procedures can be recovered by using the standard Lorentz-Einstein transformations for the space-time coordinates of the same event. Through this approach we offer modest support for the Rizzi et al. stating that: &#34;Once correctly and explicitly

  25. Pei-Hong Gu, Utpal Sarkar

    In the conventional seesaw models of neutrino masses, leptogenesis occurs at a very high scale. Three approaches have been discussed in the literature to lower the scale of leptogenesis: mass degeneracy, hierarchy of couplings and three-body decays. We advocate yet another approach to a testable leptogenesis, whereby the decaying particles could go out of eq

  26. Alexandre C Tort

    Two problems from the Victorian Age, the subdivision of light and the determination of the leakage point in an undersea telegraphic cable are discussed and suggested as a concrete illustrations of the relationships between textbook physics and the real world. Ohm&#39;s law and simple algebra are the only tools we need to discuss them in the classroom.

  27. Pei-Hong Gu, M. Hirsch, Utpal Sarkar, J. W. F. Valle

    We suggest a hybrid seesaw model where relatively ``light&#39;&#39;right-handed neutrinos give no contribution to the neutrino mass matrix due to a special symmetry. This allows their Yukawa couplings to the standard model particles to be relatively strong, so that the standard model Higgs boson can decay dominantly to a left and a right-handed neutrino, lea

  28. Mikko Malinen

    In this paper two cryptographic methods are introduced. In the first method the presence of a certain size subgroup of persons can be checked for an action to take place. For this we use fragments of Raptor codes delivered to the group members. In the other method a selection of a subset of objects can be made secret. Also, it can be proven afterwards, what

  29. Shinji Kawano

    In this article we investigate the nature of the functions, including important double power terms which arise naturally in considering typical nonlinear Schroedinger equations.

  30. A. Kormanyos, I. Grace, C. J. Lambert

    We study Andreev reflection in a normal conductor-molecule-superconductor junction using a first principles approach. In particular, we focus on a family of molecules consisting of a molecular backbone and a weakly coupled side group. We show that the presence of the side group can lead to a Fano resonance in the Andreev reflection. We use a simple theoretic

  31. P. M. Robinson

    Moving from univariate to bivariate jointly dependent long-memory time series introduces a phase parameter $(γ)$, at the frequency of principal interest, zero; for short-memory series $γ=0$ automatically. The latter case has also been stressed under long memory, along with the ``fractional differencing&#39;&#39; case $γ=(δ_2-δ_1)π/2$, where $δ_1$, $δ_2$ are

  32. Man-Duen Choi, Nathaniel Johnston, David W. Kribs

    We show that the multiplicative domain of a completely positive map yields a new class of quantum error correcting codes. In the case of a unital quantum channel, these are precisely the codes that do not require a measurement as part of the recovery process, the so-called unitarily correctable codes. Whereas in the arbitrary, not necessarily unital case the

  33. Shinji Kawano

    In this article we find the equivalent conditions to assure the existence and uniqueness of positive solutions to semilinear elliptic equations wih double power nonlinearities. As a bonus, we give a simpler proof of our former result that the uniqueness condition comes from the existence condition.

  34. T. Abete, A. de Candia, E. Del Gado, A. Fierro

    We present a systematic study of dynamical heterogeneity in a model for permanent gels, upon approaching the gelation threshold. We find that the fluctuations of the self intermediate scattering function are increasing functions of time, reaching a plateau whose value, at large length scales, coincides with the mean cluster size and diverges at the percolati

  35. Song Yang, Ming Gong, Xubo Zou, Chuanfeng Li

    We discuss the configuration and acoustic phonon effect on the conditional phase gate using self assembled quantum dots. As an example, we discuss the simplest three dots conditional phase gate, and we found that the fidelity of conditional phase gate depends strongly on the configuration and temperature. Numerical simulation shows that line-configuration re

  36. Florence Le Ber, Christian Brassac

    This paper gives an introduction to this issue, and presents the framework and the main steps of the Rosa project. Four teams of researchers, agronomists, computer scientists, psychologists and linguists were involved during five years within this project that aimed at the development of a knowledge based system. The purpose of the Rosa system is the modelli

  37. Marie Doumic Jauffret

    We study the Schrödinger equation which comes from the paraxial approximation of the Helmholtz equation in the case where the direction of propagation is tilted with respect to the boundary of the domain. This model has been proposed in (Doumic, Golse, Sentis, CRAS, 2003). Our primary interest here is in the boundary conditions successively in a half-plane,

  38. Carolina Araujo

    In this paper we characterize smooth complex projective varieties that admit a quadric bundle structure on some dense open subset in terms of the geometry of certain families of rational curves.

  39. Shinji Kawano

    We consider semilinear elliptic equations with double power nonlineaities. The condition to assure the existence of positive solutions is well-known. In the present paper, we remark that the additional condition to assure uniqueness proposed by Ouyang and Shi is unnecessary.

  40. Matti Herranen, Kimmo Kainulainen, Pyry M. Rahkila

    We derive transport equations for fermions and bosons in spatially or temporally varying backgrounds with special symmetries, by use of the Schwinger-Keldysh formalism. In a noninteracting theory the coherence information is shown to be encoded in new singular shells for the 2-point function. Imposing this phase space structure to the interacting theory lead

  41. Alireza Saffarzadeh

    In this study, based on the self-energy method and the total energy calculation, the indirect exchange coupling between two semi-infinite ferromagnetic strips (FM electrodes) separated by metallic graphene nanoribbons (GNRs) is investigated. In order to form a FM/GNR/FM junction, a graphitic region of finite length is coupled to the FM electrodes along graph

  42. Lars Andersson, Robert Beig, Bernd Schmidt

    We prove that, given a stress-free, axially symmetric elastic body, there exists, for sufficiently small values of the gravitational constant and of the angular frequency, a unique stationary axisymmetric solution to the Einstein equations coupled to the equations of relativistic elasticity with the body performing rigid rotations around the symmetry axis at

  43. Christopher van Eldik

    Recent progress in pushing the sensitivity of the Imaging Atmospheric Cherenkov Technique into the 10 mCrab regime has enabled first sensitive observations of the innermost few 100 pc of the Milky Way in Very High Energy (VHE; >100 GeV) gamma rays. These observations are a valuable tool to understand the acceleration and propagation of energetic particles ne

  44. Satoki Matsushita, Daisuke Iono, Glen R. Petitpas, Richard C. -Y. Chou

    We have used the Submillimeter Array (SMA) to make the first interferometric observations (beam size ~1&#34;) of the 12CO J=6-5 line and 435 micron (690 GHz) continuum emission toward the central region of the nearby ULIRG Arp 220. These observations resolve the eastern and western nuclei from each other, in both the molecular line and dust continuum emissio

  45. S. Anderloni, F. Benatti, R. Floreanini, A. Trombettoni

    The standard experimental techniques usually adopted in the study of the behaviour of ultracold atoms in optical lattices involve extracting the atom density profile from absorption images of the atomic sample after trap release. Quantum mechanically this procedure is described by a generalized measure (POVM); interference patterns found in absorption images

  46. M. Faber, A. N. Ivanov, P. Kienle, E. L. Kryshen

    We discuss the proposal that the &#34;Darmstadt oscillations&#34; of the orbital K-shell electron capture decay (EC) rate of the H-like heavy ions are caused by quantum beats of two coherently excited, closely spaced mass-eigenstates of decaying H-like heavy ions. We show that such a mechanism to explain the time modulation of the EC-decay rates of the H-lik

  47. G. G. Kozlov, V. S. Zapasskii, V. V. Ovsyankin

    One-dimensional defect photonic crystal (Bragg waveguide) is studied from the viewpoint of the slow light problem. The calculations are presented showing that in the TiO$_2$/SiO$_2$-based Bragg waveguide one can obtain the group index of $\sim$ 1000 and spatial decay length of $\sim$ 3 mm for a nanosecond-scale pulse. Distortion of the pulse due to the group

  48. Helmut Jerjen

    The Stromlo Missing Satellites (SMS) program is a critical endeavor to investigate whether cold dark matter cosmology is flawed in its ability to describe the matter distribution on galaxy scales or proves itself once again as a powerful theory to make observational predictions. The project will deliver unprecedented results on Milky Way satellite numbers, t

  49. J. Meijer, C. Dominik, A. de Koter, C. P. Dullemond

    We present a parameter study of self-consistent models of protoplanetary disks around Herbig AeBe stars. We use the code developed by Dullemond and Dominik, which solves the 2D radiative transfer problem including an iteration for the vertical hydrostatic structure of the disk. This grid of models will be used for several studies on disk emission and mineral

  50. Thomas Boeck, Dmitry Krasnov, Andre Thess, Oleg Zikanov

    We predict a novel flow regime in liquid metals under the influence of a magnetic field. It is characterised by long periods of nearly steady, two-dimensional flow interrupted by violent three-dimensional bursts. Our prediction has been obtained from direct numerical simulations in a channel geometry at low magnetic Reynolds number and translates into physic

  51. J. Chenevez, M. Falanga, E. Kuulkers, S. Brandt

    X-ray bursts are thermonuclear explosions on the surface of accreting neutron stars in low mass X-ray binaries. As most of the known X-ray bursters are frequently observed by INTEGRAL, an international collaboration have been taking advantage of its instrumentation to specifically monitor the occurrence of exceptional burst events lasting more than ~10 minut

  52. Yasser Roudi, Sheila Nirenberg, Peter Latham

    One of the most critical problems we face in the study of biological systems is building accurate statistical descriptions of them. This problem has been particularly challenging because biological systems typically contain large numbers of interacting elements, which precludes the use of standard brute force approaches. Recently, though, several groups have

  53. A. F. Ber, B. de Pagter, F. A. Sukochev

    In this paper we study derivations in subalgebras of $L_{0}^{wo}(ν;% \mathcal{L}(X)) $, the algebra of all weak operator measurable funtions $f:S\to \mathcal{L}(X) $, where $% \mathcal{L}(X) $ is the Banach algebra of all bounded linear operators on a Banach space $X$. It is shown, in particular, that all derivations on $L_{0}^{wo}(ν;\mathcal{L}(X)) $ are in

  54. T. A. Larsson

    In a companion paper we studied field theory in the presence of a physical observer with quantum dynamics. Here we describe the most striking consequence of this assumption: new gauge and diff anomalies arise. The relevant cocycles depend on the observer&#39;s spacetime trajectory and can hence not appear in QFT, where this quantity is never introduced. Diff

  55. T. A. Larsson

    Quantum Jet Theory (QJT) is a deformation of QFT where also the quantum dynamics of the observer is taken into account. This is achieved by introducing relative fields, labelled by locations measured by rods relative to the observer&#39;s position. In the Hamiltonian formalism, the observer&#39;s momentum is modified: p_i \to p_i - P_i, where P_i is the mome

  56. V. V. Grechnev, A. M. Uralov, V. A. Slemzin, I. M. Chertok

    We present a case study of the 13 July 2004 solar event, in which disturbances caused by eruption of a filament from an active region embraced a quarter of the visible solar surface. Remarkable are absorption phenomena observed in the SOHO/EIT 304 A channel; they were also visible in the EIT 195 A channel, in the H-alpha line, and even in total radio flux re

  57. M. E. Palistrant, I. D. Cebotari, V. A. Ursu

    The microscopic superconductivity theory in MgB2 systems in the magnetic fields directed parallel and perpendicular to the plane (ab) is built. The two energy bands of different dimensions overlapping on the Fermi surface (two-dimensional sigma- band and three-dimensional pi-band) are taken into account. The theory is built taking into account the weak dispe

  58. Ivan O. Kitov, Oleg I. Kitov, Svetlana A. Dolinskaya

    A linear and lagged relationship between inflation, unemployment and labor force change rate, p(t)=A0UE(t-t0)+A1dLF(t-t1)/LF(t-t1)+ A2, where A0, A1, and A2 are empirical country-specific coefficients, was found for developed economies. The relationship obtained for France is characterized by A0=-1, A1=4, A2=0.095, t0=4 years, and t1=4 years. For GDP deflato

  59. ZEUS Collaboration, S. Chekanov

    Beauty production in events containing two muons in the final state has been measured with the ZEUS detector at HERA using an integrated luminosity of 114 pb-1. A low transverse-momentum threshold for muon identification, in combination with the large rapidity coverage of the ZEUS muon system, gives access to almost the full phase space for beauty production

  60. Yuan Chao, Kai-Feng Chen, Shing-Kuo Chen, George W. S. Hou

    Heavy $t&#39; \to bW$ is currently being searched for at the Tevatron, but a broader spectrum should be explored at the LHC. For $m_{b&#39;} < m_{t&#39;}$, we discuss the two decay branches, $b&#39; \to tW^*$ and $t^*W$, below the $tW$ threshold, and how they merge with $b&#39; \to tW$ above threshold. We use a convolution method with five body final state,

  61. Ivan O. Kitov, Oleg I. Kitov, Svetlana A. Dolinskaya

    A linear and lagged relationship between inflation and labor force change rate, p(t)= A1dLF(t-t1)/LF(t-t1)+A2 was found for developed economies. For the USA, A1=4.0, A2=-0.03075, and t1=2 years. It provides a RMS forecasting error (RMFSE) of 0.8% at a two-year horizon for the period between 1965 and 2002 (the best among other inflation forecasting models). T

  62. Bernhard Irrgang

    This is an overview about a method of constructing ccc forcings: Suppose first that a continuous, commutative system of complete embeddings between countable forcings indexed along $ω_1$ is given. Then its direct limit satisfies ccc by a well-known theorem on finite support iterations. However, this limit has size at most $ω_1$. To get larger forcings, we do

  63. Katsuhisa Taguchi, Gen Tatara

    We study theoretically the anomalous Hall effect due to the vector spin chirality carried by the local spins in the $s$-$d$ model. We will show that the vector spin chirality indeed induces local Hall effect in the presence of the electron spin polarization, while the global Hall effect vanishes if electron transport is homogeneous. This anomalous Hall effec

  64. Ivan O. Kitov

    Growth rate of real GDP per capita is represented as a sum of two components -- a monotonically decreasing economic trend and fluctuations related to a specific age population change. The economic trend is modeled by an inverse function of real GDP per capita with a numerator potentially constant for the largest developed economies. Statistical analysis of 1

  65. Chiu Fai Wong

    I give a formula for the zeta function of a projective toric hypersurface over a finite field and estimate its Newton polygon. As an application this formula allows us to compute the exact number of rational points on the families of Calabi-Yau manifolds in Mirror Symmetry.

  66. K. Deguchi, S. Ogawara, T. Okutsu, M. Nagao

    Single-crystalline (Lu, Ca)Ba2Cu3O7-d (Lu(Ca)123) whiskers have been successfully grown using the Te-doping method. X-ray diffraction patterns of Lu(Ca)123 whiskers showed sharp (0 0 l) peaks corresponding to REBa2Cu3O7-d phase (RE = rare earth elements). Transport measurements showed that the superconducting transition occurred at 83 K in the obtained whisk

  67. Timothy Trudgian

    This paper extends the work done by Titchmarsh on Gram&#39;s Law (an attempt to locate the zeroes of the zeta-function on the critical line). Herewith it is shown that a positive proportion of Gram intervals violate Gram&#39;s Law; and also that a weaker notion of Gram&#39;s Law is valid over a positive proportion of intervals.

  68. Arnab Das

    Adiabatic quantum annealing is a paradigm of analog quantum computation, where a given computational job is converted to the task of finding the global minimum of some classical potential energy function and the search for the global potential minimum is performed by employing external kinetic quantum fluctuations and subsequent slow reduction (annealing) of

  69. Jahanfar Abouie, Saeed Mahdavifar

    We have studied the zero and low-temperature behavior of anisotropic alternating antiferromagnetic-ferromagnetic Heisenberg spin-1/2 chains in a transverse magnetic field. Using the analytical spinless fermion approach, the thermodynamic behavior of the model has been studied. We have introduced a new order parameter to distinguish the gapless Luttinger liqu

  70. F. Sorrentino, A. Alberti, G. Ferrari, V. V. Ivanov

    We report about the realization of a quantum device for force sensing at micrometric scale. We trap an ultracold $^{88}$Sr atomic cloud with a 1-D optical lattice, then we place the atomic sample close to a test surface using the same optical lattice as an elevator. We demonstrate precise positioning of the sample at the $μ$m scale. By observing the Bloch os

  71. Stanley J. Brodsky

    Initial- and final-state rescattering, neglected in the parton model, have a profound effect in QCD hard-scattering reactions, predicting single-spin asymmetries, diffractive deep inelastic scattering, diffractive hard hadronic reactions, the breakdown of the Lam Tung relation in Drell-Yan reactions, and nuclear shadowing and non-universal antishadowing--lea

  72. Shi-Jie Yang, Quan-Sheng Wu, Shiping Feng, Yu-Chuan Wen

    Spatiotemporal evolution of a confined Bose-Einstein condensate is studied by numerically integrating the time-dependent Gross-Pitaevskii equation. Self-interference between the successively expanding and reflecting nonlinear matter waves results in spiral atomic density profile, which subsequently degenerates into an embedding structure: The inner part pres

  73. B. D. Yabsley

    There have been great advances in charm physics at the B-factories in recent years, including the observation of D0-D0bar mixing and the discovery of many new hidden-charm states, some of them presumably exotic in structure. This talk reviews some of the recent Belle results, with emphasis on the hidden-charm sector. Evidence for two new charged states is pr

  74. Yuval Grossman, Yuhsin Tsai

    Models with composite singlet neutrinos can give small Majorana or Dirac masses to the active neutrinos. The mechanism is based on the fact that conserved chiral symmetries give massless neutrinos at the renormalizable level. Thus, they acquire very small masses due to non-renormalizable terms. We investigate such models in two aspects. First, we find UV com

  75. Akinobu Doté, Tetsuo Hyodo, Wolfram Weise

    The prototype of a Kbar nuclear cluster, K^-pp, has been investigated using effective KbarN potentials based on chiral SU(3) dynamics. Variational calculation shows a bound state solution with shallow binding energy B(K^-pp)=20 \pm 3 MeV and broad mesonic decay width Γ(KbarNN -> πY N)=40 - 70 MeV. The KbarN(I=0) pair in the K^-pp system exhibits a similar st

  76. Dimitris M. Christodoulou, Demosthenes Kazanas

    Five planets are presently believed to orbit the primary star of 55 Cnc, but there exists a large 5 AU gap in their distribution between the two outermost planets. This gap has attracted considerable interest because it may contain one or more lower--mass planets whose existence is not contradicted by long-term orbit stability analyses, in fact it is expecte

  77. Thibaud Normand, Eric Lauga

    In a variety of biological situations, swimming cells have to move through complex fluids. Similarly, mucociliary clearance involves the transport of polymeric fluids by beating cilia. Here, we consider the extent to which complex fluids could be exploited for force generation on small scales. We consider a prototypical reciprocal motion (i.e. identical unde

  78. Igor V. Gorelov

    The recent results on a number of searches performed at Tevatron for new phenomena beyond Standard Model are presented. The topics include the experimental tests of SUSY with mSUGRA and GMSB breaking scenarios. The latest analyses on large extra dimensions, new massive bosons are covered as well. The results are based on experimental data samples collected a

  79. Simone Piccinin, Catherine Stampfl, Matthias Scheffler

    Recent experiments on model catalysts have shown that Ag-Cu alloys have improved selectivity with respect to pure silver for ethylene epoxidation. In this paper we review our first-principles investigations on the (111) surface of this alloy and present new findings on other low index surfaces. We find that, for every surface orientation, the presence of oxy

  80. A. Kormilitzin, E. Levin

    In this talk we give a brief description of a QCD motivated model for both hard and soft interactions at high energies. In this model the long distance behaviour of the scattering amplitude is determined by the dipole scattering amplitude in the saturation domain. All phenomenological parameters for dipole-proton interaction were fitted from the deep inelast

  81. James S. Bullock, Kyle R. Stewart, Chris W. Purcell

    Disk galaxies are common in our universe and this is a source of concern for hierarchical formation models like LCDM. Here we investigate this issue as motivated by raw merger statistics derived for galaxy-size dark matter halos from LCDM simulations. Our analysis shows that a majority (~70%) of galaxy halos with M = 10^12 M_sun at z=0 should have accreted a

  82. Nagalakshmi A Rao, B A Kagali

    In the present paper, we work out the eigenfunctions of spinless particles bound in a one-dimensional linear finite range, attractive potential well, treating it as a time-like component of a four-vector. We show that the one-dimensional stationary Klein-Gordon equation is reduced to a standard differential equation, whose solutions, consistent with the boun

  83. Evgeny A. Shapiro, Valery Milner, Moshe Shapiro

    We develop a method for executing robust and selective transfer of populations between a single level and pre-selected superpositions of energy eigenstates. Viewed in the frequency domain, our method amounts to executing a series of simultaneous adiabatic passages into each component of the target superposition state. Viewed in {the} time domain, the method

  84. A. Das

    In the arena of the discrete phase space and continuous time, the theory of S-marix is formulated. In the special case of Quantum-Electrodynamics (QED), the Feynman rules are precisely developed. These rules in the fourmomentum turn out to be identical to the usual QED, except for the vertex function. The new vertex function is given by an infinite series wh

  85. A. Das

    The Klein-Gordon equation, the Maxwell equation, and the Dirac equation are presented as partial difference equations in the eight-dimensional covariant discrete phase space. These equations are also furnished as difference-differential equations in the arena of discrete phase space and continuous time. The scalar field and electromagnetic fields are quantiz

  86. A. Das

    The classical relativistic wave equations are presented as partial difference equations in the arena of covariant discrete phase space. These equations are also expressed as difference-differential equations in discrete phase space and continuous time. The relativistic invariance and covariance of the equations in both versions are established. The partial d

  87. John D. Beasley

    This special issue on Peg Solitaire has been put together by John Beasley as guest editor, and reports work by John Harris, Alain Maye, Jean-Charles Meyrignac, George Bell, and others. Topics include: short solutions on the 6 x 6 board and the 37-hole &#34;French&#34; board, solving generalized cross boards and long-arm boards. Five new problems are given fo

  88. Huan Wang, Ka-Di Zhu

    We demonstrate that voltage-controlled negative index can be obtained in self-organized InAs quantum dot systems. As the bias voltage changes, the refractive index can be adjusted and controlled continuously from -7 to 7. Simultaneously, the absorption of light in the system will be very small. The single-negative index materials and the double-negative inde

  89. Nicole F. Bell

    We review the prospects for probing new physics with neutrino astrophysics. High energy neutrinos provide an important means of accessing physics beyond the electroweak scale. Neutrinos have a number of advantages over conventional astronomy and, in particular, carry information encoded in their flavor degree of freedom which could reveal a variety of exotic

  90. E. Ramirez Barreto, Y. A. Coutinho, J. Sá Borges

    The production of $W^+ W^-$ pair in hadron colliders was calculated up to loop corrections by some authors in the Electroweak standard model (SM) framework. This production was also calculated, at the tree level, in some extensions of the SM such as the vector singlet, the fermion mirror fermion and the vector doublet models by considering the contributions

  91. D. Batcheldor, G. Schneider, D. C. Hines, G. D. Schmidt

    The ability of NICMOS to perform high accuracy polarimetry is currently hampered by an uncalibrated residual instrumental polarization at a level of 1.2-1.5%. To better quantify and characterize this residual we obtained observations of three polarimetric standard stars at three separate space-craft roll angles. Combined with archival data, these observation

  92. A. Lazarian

    We discuss a long-standing problem of how turbulence can be studied using observations of Doppler broadened emission and absorption lines. The focus of the present review is on two new techniques, the Velocity-Channel Analysis (VCA), which makes use of the channel maps, and the Velocity Coordinate Spectrum (VCS), which utilizes the fluctuations measured alon

  93. Jang Young Bang, Micheal S Berger

    The properties of quantum mechanics with a discrete phase space are studied. The minimum uncertainty states are found, and these states become the Gaussian wave packets in the continuum limit. With a suitably chosen Hamiltonian that gives free particle motion in the continuum limit, it is found that full or approximate periodic time evolution can result. Thi

  94. Mark Colarusso

    In recent work Bertram Kostant and Nolan Wallach ([KW1], [KW2]) have defined an interesting action of a simply connected Lie group $A$ isomorphic to \mathbb{C}^{n\choose 2} on gl(n) using a completely integrable system derived from Gelfand-Zeitlin theory. In this paper we show that an analogous action of \mathbb{C}^{d} exists on the complex orthogonal Lie al

  95. A. Chrupnov, A. Lazarian

    Turbulent motions induce Doppler shifts of observable emission and absorption lines motivating studies of turbulence using precision spectroscopy. We provide the numerical testing of the two most promising techniques, Velocity Channel Analysis (VCA) and Velocity Coordinate Spectrum (VCS). We obtain an expression for the shot noise that the discretization of

  96. Jie Lou, Anders W. Sandvik

    We discuss ground-state projector simulations of a modified two-dimensional S=1/2 Heisenberg model in the valence bonds basis. Tuning matrix elements corresponding to the diagonal and off-diagonal terms in the quantum dimer model, we show that there is a quantum phase transition from the antiferromagnet into a columnar valence-bond-solid (VBS). There are no

  97. Paolo Creminelli, Guido D&#39;Amico, Jorge Noreña, Filippo Vernizzi

    We study generic single-field dark energy models, by a parametrization of the most general theory of their perturbations around a given background, including higher derivative terms. In appropriate limits this approach reproduces standard quintessence, k-essence and ghost condensation. We find no general pathology associated to an equation of state w_Q < -1

  98. D. H. Zhao, Y. P. Jing, H. J. Mo, G. Boerner

    A large amount of observations have constrained cosmological parameters and the initial density fluctuation spectrum to a very high accuracy. However, cosmological parameters change with time and the power index of the power spectrum varies with mass scale dramatically in the so-called concordance Lambda CDM cosmology. Thus, any successful model for its stru

  99. E. T. Million, S. W. Allen

    We report the discovery of spatially-extended, non-thermal-like emission components in Chandra X-ray spectra for five of a sample of seven massive, merging galaxy clusters with powerful radio halos. The emission components can be fitted by power-law models with mean photon indices in the range 1.5 < Gamma < 2.0. A control sample of regular, dynamically relax

  100. J. I. Thorpe, S. T. McWilliams, B. J. Kelly, R. P. Fahey

    Recent advances in numerical relativity provide a detailed description of the waveforms of coalescing massive black hole binaries (MBHBs), expected to be the strongest detectable LISA sources. We present a preliminary study of LISA&#39;s sensitivity to MBHB parameters using a hybrid numerical/analytic waveform for equal-mass, non-spinning holes. The Syntheti