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September 2007 arXiv papers — page 43

Showing 4,201–4,300 of 4,824 papers

  1. J. Thomas, R. P. Saglia, R. Bender, D. Thomas

    Dynamical models for 17 Coma early-type galaxies are presented. The galaxy sample consists of flattened, rotating as well as non-rotating early-types including cD and S0 galaxies with luminosities between M=-18.79 and M=-22.56. Kinematical long-slit observations cover at least the major and minor axis and extend to 1-4 effective radii. Axisymmetric Schwarzsc

  2. Martin R. Bridson, Michael Tweedale

    Let $G$ be the right-angled Artin group associated to the flag complex $Σ$ and let $π:G\to\Z$ be its canonical height function. We investigate the presentation theory of the groups $Γ_n=π^{-1}(n\Z)$ and construct an algorithm that, given $n$ and $Σ$, outputs a presentation of optimal deficiency on a minimal generating set, provided $Σ$ is triangle-free; the

  3. Nicolas Vuillerme, Olivier Chenu, Nicolas Pinsault, Anthony Fleury

    Maintaining an upright stance represents a complex task, which is achieved by integrating sensory information from the visual, vestibular and somatosensory systems. When one of these sensory inputs becomes unavailable and/or inaccurate and/or unreliable, postural control generally is degraded. One way to solve this problem is to supplement and/or substitute

  4. Marek Bucki, Claudio Lobos, Yohan Payan

    In this paper we present a methodology to address the problem of brain tissue deformation referred to as 'brain-shift'. This deformation occurs throughout a neurosurgery intervention and strongly alters the accuracy of the neuronavigation systems used to date in clinical routine which rely solely on pre-operative patient imaging to locate the surgica

  5. Daniel Kennefick

    The 1919 Eclipse Expedition to test the light-bending prediction of General Relativity remains one of the most famous physics experiments of the 20th century. However, in recent decades it has been increasingly often alleged that the data-analysis of the expedition's leaders was faulty and biased in favor of Einstein's theory. Arthur Stanley Eddingto

  6. M. J. Graf, J. Lago, A. Lascialfari, A. Amato

    We have studied the Ho3+ spin dynamics for LiY0.998Ho0.002F4 through the positive muon (mu+) transverse field depolarization rate lambda_TF as a function of temperature and magnetic field. We find sharp reductions in lambda_TF(H) at fields of 23, 46 and 69 mT, for which the Ho3+ ion system has field-induced (avoided) level crossings. The reduction scales wit

  7. Marek Bucki, Claudio Lobos, Yohan Payan

    In this paper we present a methodology to address the problem of brain tissue deformation referred to as 'brain-shift'. This deformation occurs throughout a neurosurgery intervention and strongly alters the accuracy of the neuronavigation systems used to date in clinical routine which rely solely on pre-operative patient imaging to locate the surgica

  8. Nicolas Vuillerme, Olivier Chenu, Nicolas Pinsault, Alexandre Moreau-Gaudry

    We introduce the innovative technologies, based on the concept of "sensory substitution", we are developing in the fields of biomedical engineering and human disability. Precisely, our goal is to design, develop and validate practical assistive biomedical and/or technical devices and/or rehabilitating procedures for persons with disabilities, using a

  9. Antoine Rennuit, Alain Micaelli, Claude Andriot, François Guillaume

    In the industry, numerous commercial packages provide tools to introduce, and analyse human behaviour in the product's environment (for maintenance, ergonomics...), thanks to Virtual Humans. We will focus on control. Thanks to algorithms newly introduced in recent research papers, we think we can provide an implementation, which even widens, and simplifi

  10. Joshua W. Shaevitz, Daniel A. Fletcher

    Intracellular pathogens such as Listeria monocytogenes and Rickettsia rickettsii move within a host cell by polymerizing a comet-tail of actin fibers that ultimately pushes the cell forward. This dense network of cross-linked actin polymers typically exhibits a striking curvature that causes bacteria to move in gently looping paths. Theoretically, tail curva

  11. Binhai Zhu

    We show that given $m$ proteins (or protein backbones, which are modeled as 3D polygonal chains each of length O(n)) the problem of protein local structure alignment under the discrete Fréchet distance is as hard as Independent Set. So the problem does not admit any approximation of factor $n^{1-ε}$. This is the strongest negative result regarding the protei

  12. Matthew J. Payne, Giuseppe Lodato

    Recent observations point to the presence of structured dust grains in the discs surrounding young brown dwarfs, thus implying that the first stages of planet formation take place also in the sub-stellar regime. Here, we investigate the potential for planet formation around brown dwarfs and very low mass stars according to the sequential core accretion model

  13. N. Belmechri, G. Abramovici, M. Heritier, S. Haddad

    We propose a theoretical model of quasi-one-dimensional superconductors, with attractive electron-electron interactions dominant in the singlet d-wave channel and sub-dominant in the p-wave channel. We discuss, in the mean field approximation, the effect of a magnetic field applied perpendicularly to the direction of the lowest conductivity. The lowest free

  14. Juergen Schmidhuber

    I postulate that human or other intelligent agents function or should function as follows. They store all sensory observations as they come - the data is holy. At any time, given some agent's current coding capabilities, part of the data is compressible by a short and hopefully fast program / description / explanation / world model. In the agent's su

  15. E. Sauvan

    We present a search for excited neutrinos and electrons using all data collected by the H1 experiment at HERA at a center-of-mass energy of 320 GeV with an integrated luminosity of up to 435 pb$^{-1}$. No evidence for excited neutrino or electron production is found. Mass dependent exclusion limits are determined for the ratio of the coupling to the composit

  16. Paul Baird, Radu Pantilie

    We prove that any (real or complex) analytic horizontally conformal submersion from a three-dimensional conformal manifold M to a two-dimensional conformal manifold N can be, locally, `extended' to a unique harmonic morphism from the heaven space of M to N.

  17. Daniil Ryabko, Juergen Schmidhuber

    Nonparametric rank tests for homogeneity and component independence are proposed, which are based on data compressors. For homogeneity testing the idea is to compress the binary string obtained by ordering the two joint samples and writing 0 if the element is from the first sample and 1 if it is from the second sample and breaking ties by randomization (exte

  18. Guido Cossu, Massimo D'Elia, Adriano Di Giacomo, Biagio Lucini

    The gauge group being centreless, $G_2$ gauge theory is a good laboratory for studying the role of the centre of the group for colour confinement in Yang-Mills gauge theories. In this paper, we investigate $G_2$ pure gauge theory at finite temperature on the lattice. By studying the finite size scaling of the plaquette, the Polyakov loop and their susceptibi

  19. Andreia Dionisio, Rui Menezes, Diana A. Mendes

    The investor is interested in the expected return and he is also concerned about the risk and the uncertainty assumed by the investment. One of the most popular concepts used to measure the risk and the uncertainty is the variance and/or the standard-deviation. In this paper we explore the following issues: Is the standard-deviation a good measure of risk an

  20. Ivan V. Losev

    Let G be a connected reductive group. To any irreducible G-variety one assigns the lattice generated by all weights of B-semiinvariant rational functions on X, where B$ is a Borel subgroup of G. This lattice is called the weight lattice of X. We establish algorithms for computing weight lattices for homogeneous spaces and affine homogeneous vector bundles. F

  21. M. Hauer, V. V. Begun, M. Gazdzicki, M. I. Gorenstein

    Multiplicity distributions of hadrons produced in central nucleus-nucleus collisions are studied within the hadron-resonance gas model in the large volume limit. In the canonical ensemble conservation of three charges (baryon number, electric charge, and strangeness) is enforced. In addition, in the micro-canonical ensemble energy conservation is included. A

  22. Y. He, S. Graser, P. J. Hirschfeld, H. -P. Cheng

    We present results of density functional theory (DFT) calculation of the structural supermodulation in BSCCO-2212 structure, and show that the supermodulation is indeed a spontaneous symmetry breaking of the nominal crystal symmetry, rather than a phenomenon driven by interstitial O dopants. The structure obtained is in excellent quantitative agreement with

  23. Timothy H. Boyer

    The long-standing controversy regarding the Aharonov-Bohm phase shift is reviewed. The shifts of both optical and particle interference patterns are summarized. It is pointed out that a line of electric dipoles and a line of magnetic dipoles (a long solenoid) both produce experimentally observed phase shifts similar to that produced by introducing a rectangu

  24. Lap-Ming Lin, N. Andersson, G. L. Comer

    We develop the formalism for determining the quasinormal modes of general relativistic multi-fluid compact stars in such a way that the impact of superfluid gap data can be assessed. Our results represent the first attempt to study true multi-layer dynamics, an important step towards considering realistic superfluid/superconducting compact stars. We combine

  25. Stefano Zibetti

    The presence of a diffuse stellar component in galaxy clusters has been established by a number of observational works in recent years. In this contribution I summarize our results (Zibetti et al. 2005) obtained by stacking SDSS images of 683 clusters, selected with the maxBCG algorithm at 0.2< z <0.3. Thanks to our large sample and the advantages of image s

  26. A. Pipino, F. Matteucci, A. D&#39;Ercole

    We present a new class of hydrodynamical models for the formation of bulges (either massive elliptical galaxies or classical bulges in spirals) in which we implement detailed prescriptions for the chemical evolution of H, He, O and Fe. Our results hint toward an outside-in formation in the context of the supernovae-driven wind scenario. The build-up of the c

  27. Philip W Anderson

    I present a formalism for dealing directly with the effects of the Gutzwiller projection, which is implicit in the t-J model widely believed to underly the phenomenology of the high-Tc cuprates. I suggest that a true BCS condensation from a Fermi liquid state takes place, but in the unphysical space prior to projection. The theory which results upon projecti

  28. Sebastiano Cantalupo, Cristiano Porciani, Simon J. Lilly

    We present a new method to directly map the neutral-hydrogen distribution during the reionization epoch and to constrain the emission properties of the highest-redshift quasars (QSOs). As a tracer of HI, we propose to use the Ly-alpha radiation produced by quasar ionization fronts (I-fronts) that expand in the partially ionized intergalactic medium (IGM) bef

  29. Irene D&#39;Amico, Brendon W. Lovett, Timothy P. Spiller

    We show how multi-partite entanglement, such as of W-state form, can be created in branched spin chain systems. We also discuss the preservation of such entanglement, once created. The technique could be applied to actual spin chain systems, or to other physical systems such as strings of coupled quantum dots, molecules or atoms.

  30. Muhammad Shoaib

    We investigate the stability of few body symmetrical dynamical systems which include four and five body symmetrical dynamical systems. Research presented in this thesis includes the following original investigations: determination of some analytical solutions of the four body problem; stability analysis of the near symmetric coplanar CSFBP ; derivation of th

  31. Maria Grazia Bernardini, Carlo Luciano Bianco, Letizia Caito, Maria Giovanna Dainotti

    (Shortened) The Swift and HETE-2 discovery of an afterglow associated possibly with short GRBs opened the new problematic of their nature and classification. This has been further enhanced by the GRB060614 observation and by a re-analysis of the BATSE catalog leading to the identification of a new GRB class with &#34;an occasional softer extended emission la

  32. Lothar Heinrich, Hendrik Schmidt, Volker Schmidt

    We observe stationary random tessellations $X=\{Ξ_n\}_{n\ge1}$ in $\mathbb{R}^d$ through a convex sampling window $W$ that expands unboundedly and we determine the total $(k-1)$-volume of those $(k-1)$-dimensional manifold processes which are induced on the $k$-facets of $X$ ($1\le k\le d-1$) by their intersections with the $(d-1)$-facets of independent and

  33. A. Messad

    Using the Tc formula given by BCS, together with a shear modulus varying with the numbering of planes, we can demonstrate that Tc oscillates depending on the number of the cuprate planes. The maximum of Tc in these oscillations appears for three planes irrespective of the cuprate family. Comparison with experimental data shows good agreement and suggests tha

  34. Santiago Boza, Javier Soria

    For a general set transformation ${\cal R}$ between two measure spaces, we define the rearrangement of a measurable function by means of the Layer&#39;s cake formula. We study some functional properties of the Lorentz spaces defined in terms of ${\cal R}$, giving a unified approach to the classical rearrangement, Steiner&#39;s symmetrization, the multidimens

  35. Sorina Barza, Viktor Kolyada, Javier Soria

    We study the Lorentz spaces $L^{p,s}(R,μ)$ in the range $1<p<s\le \infty$, for which the standard functional $$ ||f||_{p,s}=(\int_0^\infty (t^{1/p}f^*(t))^s\frac{dt}{t})^{1/s} $$ is only a quasi-norm. We find the optimal constant in the triangle inequality for this quasi-norm, which leads us to consider the following decomposition norm: $$ ||f||_{(p,s)}=\inf

  36. N. M. R. Peres, Eduardo V. Castro

    We present an exact algebraic solution of a single graphene plane in transverse electric and perpendicular magnetic fields. The method presented gives both the eigen-values and the eigen-functions of the graphene plane. It is shown that the eigen-states of the problem can be casted in terms of coherent states, which appears in a natural way from the formalis

  37. Y. J. Liu, Bun&#39;ei Sato, G. Zhao, Kunio Noguchi

    We report the detection of a substellar companion orbiting the intermediate-mass giant star 11 Com (G8 III). Precise Doppler measurements of the star from Xinglong station and Okayama Astrophysical Observatory (OAO) revealed Keplerian velocity variations with an orbital period of 326.03 +/- 0.32 days, a semiamplitude of 302.8 +/- 2.6 m/s, and an eccentricity

  38. A. M. Lobos, A. A. Aligia

    We study the conductance through a ring described by the Hubbard model (such as an array of quantum dots), threaded by a magnetic flux and subject to Rashba spin-orbit coupling (SOC). We develop a formalism that is able to describe the interference effects as well as the Kondo effect when the number of electrons in the ring is odd. In the Kondo regime, the S

  39. Garcia de Andrade

    Geometry of Liquid crystals as detectors of HIV twisted helical filaments is presented.

  40. I. F. Barna, P. Dombi

    Coherent control calculations are presented for a spherically symmetric box potential for non-resonant two photon transition probabilities. With the help of a genetic algorithm (GA) the population of the excited states are maximized and minimized. The external driving field is a superposition of three intensive extreme ultraviolet (XUV) linearly polarized la

  41. Kenichi Bannai, Shinichi Kobayashi

    In this paper, we give an overview of our previous paper concerning the investigation of the algebraic and $p$-adic properties of Eisenstein-Kronecker numbers using Mumford&#39;s theory of algebraic theta functions.

  42. A. J. Korn, F. Grundahl, O. Richard, P. S. Barklem

    We present a homogeneous photometric and spectroscopic analysis of 18 stars along the evolutionary sequence of the metal-poor globular cluster NGC 6397 ([Fe/H] = -2), from the main-sequence turnoff point to red giants below the bump. The spectroscopic stellar parameters, in particular stellar-parameter differences between groups of stars, are in good agreeme

  43. Brahim Boufoussi, Marco Dozzi, Raby Guerbaz

    We establish estimates for the local and uniform moduli of continuity of the local time of multifractional Brownian motion, $B^H=(B^{H(t)}(t),t\in\mathbb{R}^+)$. An analogue of Chung&#39;s law of the iterated logarithm is studied for $B^H$ and used to obtain the pointwise Hölder exponent of the local time. A kind of local asymptotic self-similarity is proved

  44. Gerhard Hensler, Simone Recchi, Danica Kroeger, Tim Freyer

    By a few but important examples as models of combined radiative and wind-driven HII regions and galactic winds we demonstrate the importance of refined small-to-medium scale studies of chemo-dynamical effects. These processes determine the internal dynamics and energetic of the ISM and affect its observational signatures, e.g. by abundance contributions, but

  45. Hiroyasu Tajima

    The origin of the cosmic rays has been a great mystery since they were discovered by Victor Hess in 1912. AGASA&#39;s observation of ultra-high-energy cosmic-rays (UHECR) possibly beyond the GZK (Greisen, Zatsepin and Kuzmin) cutoff stimulated the field in great deal. In addition, Kamiokande&#39;s detection of neutrinos from SN1987A and the H.E.S.S.&#39;s de

  46. V. A. McBride, M. J. Coe, A. J. Bird, A. J. Dean

    The first INTEGRAL observations of the Small Magellanic Cloud (carried out in 2003) are reported in which two sources are clearly detected. The first source, SMC X-1, shows a hard X-ray eclipse and measurements of its pulse period indicate a continuation of the long-term spin-up now covering ~30 years. The second source is likely to be a high mass X-ray bina

  47. Gerhard Hensler

    Here results of numerical radiation hydrodynamical simulations are presented which explore the energetic impact of massive stars on the interstellar medium. We study the evolution of the ambient gas around isolated massive stars in the mass range between 15 and 85 Msun in order to analyze the formation of structures and further the transfer and deposit of th

  48. Tae-il Hur, P. Ko, Xiao-Hong Wu

    We present the phenomenology of antisymmetric rank-2 tensor unparticle operator ${\cal O}_{\cal U,A}^{μν}$ with scaling dimension $d_{\cal U}$. We consider the physical effects of operator $O_{\cal U,A}^{μν}$ in $Z^0$ boson invisible decays $Z^0 \to {\cal U}$, $Z^0 \to b \bar{b}$ channel, the electroweak precision observable $S$ parameter, and the muon anoma

  49. Michael Wilczek, Oliver Kamps, Rudolf Friedrich

    We present a numerical investigation of two-dimensional decaying turbulence in the Lagrangian framework. Focusing on single particle statistics, we investigate Lagrangian trajectories in a freely evolving turbulent velocity field. The dynamical evolution of the tracer particles is strongly dominated by the emergence and evolution of coherent structures. For

  50. Xavier Bardina, Carles Rovira

    Bardina and Jolis [Stochastic process. Appl. 69 (1997) 83--109] prove an extension of Itô&#39;s formula for $F(X_t,t)$, where $F(x,t)$ has a locally square-integrable derivative in $x$ that satisfies a mild continuity condition in $t$ and $X$ is a one-dimensional diffusion process such that the law of $X_t$ has a density satisfying certain properties. This f

  51. Andreas Christmann, Ingo Steinwart

    We investigate statistical properties for a broad class of modern kernel-based regression (KBR) methods. These kernel methods were developed during the last decade and are inspired by convex risk minimization in infinite-dimensional Hilbert spaces. One leading example is support vector regression. We first describe the relationship between the loss function

  52. Katharina Lürwer-Brüggemeier, Martin Ziegler

    The unit cost model is both convenient and largely realistic for describing integer decision algorithms over (+,*). Additional operations like division with remainder or bitwise conjunction, although equally supported by computing hardware, may lead to a considerable drop in complexity. We show a variety of concrete problems to benefit from such NON-arithmet

  53. W. Vieser, G. Hensler

    Shortened version: The fate of IS clouds embedded in a hot tenuous medium depends on whether the clouds suffer from evaporation or whether material condensates onto them. Analytical solutions for the rate of evaporative mass loss from an isolated spherical cloud embedded in a hot tenuous gas are deduced by Cowie & McKee (1977). In order to test the validity

  54. Aldéric Joulin

    In this paper, we present new Poisson-type deviation inequalities for continuous-time Markov chains whose Wasserstein curvature or $Γ$-curvature is bounded below. Although these two curvatures are equivalent for Brownian motion on Riemannian manifolds, they are not comparable in discrete settings and yield different deviation bounds. In the case of birth--de

  55. Ignacio Trujillo, Christopher J. Conselice, Kevin Bundy, M. C. Cooper

    Using the combined capabilities of the large near-infrared Palomar/DEEP-2 survey, and the superb resolution of the ACS HST camera, we explore the size evolution of 831 very massive galaxies (M*>10^{11}h_{70}^{-2}M_sun) since z~2. We split our sample according to their light concentration using the Sersic index n. At a given stellar mass, both low (n<2.5) and

  56. Raúl Gouet, F. Javier López, Gerardo Sanz

    Let $\{X_n,n\ge1\}$ be a sequence of independent and identically distributed random variables, taking non-negative integer values, and call $X_n$ a $δ$-record if $X_n>\max\{X_1,...,X_{n-1}\}+δ$, where $δ$ is an integer constant. We use martingale arguments to show that the counting process of $δ$-records among the first $n$ observations, suitably centered an

  57. Wilfred W. F. Frieswijk, Marco Spaans, Russell F. Shipman, David Teyssier

    In the inner parts of the Galaxy the Infrared Dark Clouds (IRDCs) are presently believed to be the progenitors of massive stars and star clusters. Many of them are predominantly devoid of active star formation and for now they represent the earliest observed stages of massive star formation. Their Outer Galaxy counterparts, if present, are not easily identif

  58. L. Samaj

    This is a short review about liquid-vapor and crystalline phase transitions in continuum and lattice Widom-Rowlinson models.

  59. S. V. Chernov, V. I. Dokuchaev

    We construct the classification scheme for all possible evolution scenarios and find the corresponding global geometries for dynamics of a thin spherical vacuum shell in the Schwarzschild-de Sitter metric. This configuration is suitable for the modelling of vacuum bubbles arising during cosmological phase transitions in the early Universe. The distinctive fi

  60. Lev Chuntonov, Leonid Rybak, Andrey Gandman, Zohar Amitay

    Coherent control of femtosecond two-photon absorption in the intermediate-field regime is analyzed in detail in the powerful frequency domain using an extended 4th-order perturbative description. The corresponding absorption is coherently induced by the weak-field non-resonant two-photon transitions as well as by four-photon transitions involving three absor

  61. Craig J. Hogan

    A theory is developed to describe the nonlocal effect of spacetime quantization on position measurements transverse to macroscopic separations. Spacetime quantum states close to a classical null trajectory are approximated by plane wavefunctions of Planck wavelength (l_P) reference beams; these are used to connect transverse position operators at macroscopic

  62. R. S. Priddey, R. J. Ivison, K. G. Isaak

    The most massive haloes at high redshift are expected, according to hierarchical cosmologies, to reside in the most biased density fields. If powerful active galactic nuclei (AGN) are expected to exist anywhere in the early Universe (z>5), it is within these massive haloes. The most luminous of these AGN, powered by supermassive black holes (SMBHs) ~10^9Msun

  63. J. Moser, A. Barreiro, A. Bachtold

    A simple yet highly reproducible method to suppress contamination of graphene at low temperature inside the cryostat is presented. The method consists of applying a current of several mA through the graphene device, which is here typically a few $μ$m wide. This ultra-high current density is shown to remove contamination adsorbed on the surface. This method i

  64. J. A. Green, A. M. S. Richards, W. H. T. Vlemmings, P. Diamond

    MERLIN observations of 6.668-GHz methanol and both 6.031- and 6.035-GHz hydroxyl (OH) emission from the massive star-formation region ON1 are presented. These are the first methanol observations made in full polarization using 5 antennas of MERLIN, giving high resolution and sensitivity to extended emission. Maser features are found to lie at the southern ed

  65. William G. Alway, Jonathan A. Jones

    We discuss the implementation of arbitrary precision composite pulses developed using the methods of Brown et al. [Phys. Rev. A 70 (2004) 052318]. We give explicit results for pulse sequences designed to tackle both the simple case of pulse length errors and for the more complex case of off-resonance errors. The results are developed in the context of NMR qu

  66. Andrey Gandman, Lev Chuntonov, Leonid Rybak, Zohar Amitay

    We study in detail coherent phase control of femtosecond resonance-mediated (2+1) three-photon absorption and its dependence on the spectral bandwidth of the excitation pulse. The regime is the weak-field regime of third perturbative order. The corresponding interference mechanism involves a group of three-photon excitation pathways that are on resonance wit

  67. G. K. Eleftherakis

    Two unital operator algebras A, B are called Delta-equivalent if there exists an equivalence functor between the categories A-mod and B-mod which &#34;extends&#34; to a *-functor implementing an equivalence between the categories A-dmod and B-dmod. Here A-mod denotes the category of normal representations of A and A-dmod denotes the category with the same ob

  68. Arnaud Begyn

    Cohen, Guyon, Perrin and Pontier have given assumptions under which the second-order quadratic variations of a Gaussian process converge almost surely to a deterministic limit. In this paper we present two new convergence results about these variations: the first is a deterministic asymptotic expansion; the second is a central limit theorem. Next we apply th

  69. A. Asensio Ramos, M. J. Martinez Gonzalez, J. A. Rubino-Martin

    [abridged] Inversion techniques are the most powerful methods to obtain information about the thermodynamical and magnetic properties of solar and stellar atmospheres. In the last years, we have witnessed the development of highly sophisticated inversion codes that are now widely applied to spectro-polarimetric observations. The majority of these inversion c

  70. F. T. Vasko, A. Hernandez-Cabrera, P. Aceituno

    We have considered the ballistic propagation of the 2D electron Wigner distribution, which is excited by an ultrashort optical pulse from a short-range impurity into the first quantized subband of a selectively-doped heterostructure with high mobility. Transient ionization of a deep local state into a continuum conduction c-band state is described. Since the

  71. I. V. Dinu, M. Tolea, A. Aldea

    We apply the Keldysh formalism in order to derive a current formula easy to use for a system with many sites, one of which is interacting. The main technical challenge is to deal with the lesser Green function. It turns out that, in the case of the left-right symmetry, the knowledge of the lesser Green function is not necessary and an exact current formula c

  72. Andreia Dionisio, A. Heitor Reis

    The maximum entropy principle can be used to assign utility values when only partial information is available about the decision maker&#39;s preferences. In order to obtain such utility values it is necessary to establish an analogy between probability and utility through the notion of a utility density function. According to some authors [Soofi (1990), Abba

  73. Satoshi Mayama, Motohide Tamura, Masahiko Hayashi, Yoichi Itoh

    We conducted sub-arcsecond near-infrared imaging observations of RNO91 with CIAO mounted on the SUBARU 8.2 m telescope. We present our JHK band data along with optical images, which when considered together reveal a complex circumstellar structure. We examined the colors of associated nebula and compared the geometry of the outflow/disk system suggested by o

  74. Zeev Vager

    In equilibrium, the number of conduction electrons in a solid substance depends on the conformation of the atoms in the substance. When a magnetic field is applied, it takes time for the system to come to a new equilibrium with a new conformation. During such times, current may flow. But, unless superconduction is involved, the new equilibrium contains no cu

  75. Giorgio Torrieri

    We explain how fluctuations of ratios can constrain and falsify the statistical model of particle production in heavy ion collisions, using $K/π$ fluctuations as an example. We define an observable capable of determining which statistical model, if any, governs freeze-out in ultrarelativistic heavy ion collisions. We calculate this observable for $K/π$ fluct

  76. Karl Gebhardt, Tod R. Lauer, Jason Pinkney, Ralf Bender

    The largest galaxies, and in particular central galaxies in clusters, offer unique insight into understanding the mechanism for the growth of nuclear black holes. We present Hubble Space Telescope kinematics for NGC1399, the central galaxy in Fornax. We find the best-fit model contains a black hole of 5.1 +-0.7 x 10^8 Msun (at a distance of 21.1 Mpc), a fact

  77. Guillaume Haiat, Etienne Barthel

    Surface roughness is known to easily suppress the adhesion of elastic surfaces. Here a simple model for the contact of \emph{viscoelastic} rough surfaces with significant levels of adhesion is presented. This approach is derived from our previous model [E. Barthel and G. Haiat {\em Langmuir}, 18 9362 2002] for the adhesive contact of viscoelastic spheres. Fo

  78. Giulio Biroli, Cristina Toninelli

    The Spiral Model (SM) corresponds to a new class of kinetically constrained models introduced in joint works with D.S. Fisher [8,9]. They provide the first example of finite dimensional models with an ideal glass-jamming transition. This is due to an underlying jamming percolation transition which has unconventional features: it is discontinuous (i.e. the pe

  79. Anirvan Dasgupta, Hemwati Nandan, Sayan Kar

    We investigate the kinematics of deformations in two and three dimensional media by explicitly solving (analytically) the evolution equations (Raychaudhuri equations) for the expansion, shear and rotation associated with the deformations. The analytical solutions allow us to study the dependence of the kinematical quantities on initial conditions. In particu

  80. Ing-Guey Jiang, Li-Chin Yeh, Yen-Chang Chang, Wen-Liang Hung

    In addition to fitting the data of 233 extra-solar planets with power laws, we construct a correlated mass-period distribution function of extrasolar planets, as the first time in this field. The algorithm to generate a pair of positively correlated beta-distributed random variables is introduced and used for the construction of correlated distribution funct

  81. V. A. Marchenko, A. V. Nikulov

    The phase transition from the Abrikosov state to the normal state with superconducting fluctuations observed below the second critical field and well-known as vortex lattice melting was one of the most popular problems in the nineties. This problem had became popular after the discovery of high-Tc superconductors because the fluctuation phenomena are much st

  82. David Ehrenreich, Guillaume Hébrard, Alain Lecavelier Des Etangs, David K Sing

    We present Spitzer Space Telescope observations of the extrasolar planet HD189733b primary transit, obtained simultaneously at 3.6 and 5.8 microns with the Infrared Array Camera. The system parameters, including planetary radius, stellar radius, and impact parameter are derived from fits to the transit light curves at both wavelengths. We measure two consist

  83. L. N. Bulaevskii, C. D. Batista, M. Mostovoy, D. Khomskii

    The standard view is that at low energies Mott insulators exhibit only magnetic properties while charge degrees of freedom are frozen out as the electrons become localized by a strong Coulomb repulsion. We demonstrate that this is in general not true: for certain spin textures {\it spontaneous circular electric currents} or {\it nonuniform charge distributio

  84. Marian Karlicky

    We study an acceleration of electrons and positrons in the relativistic magnetic field reconnection using a 2.5-D particle-in-cell electromagnetic relativistic code. We consider the model with two current sheets and periodic boundary conditions. The electrons and positrons are very effectively accelerated during the tearing and coalescence processes of the r

  85. Akira Onuki

    We present a general theory of thermoacoustic phenomena in supercritical fluids near the critical point in a one-dimensional cell. We take into account the effects of the heat conduction in the boundary walls and the bulk viscosity near the critical point. We introduce a coefficient $Z(ω)$ characterizing reflection of sound with frequency $ω$ at the boundary

  86. Kaori Nagashima, Takashi Sekii, Alexander G. Kosovichev, Hiromoto Shibahashi

    Exploiting high-resolution observations made by the Solar Optical Telescope onboard Hinode, we investigate the spatial distribution of power spectral density of oscillatory signal in and around NOAA active region 10935. The G-band data show that in the umbra the oscillatory power is suppressed in all frequency ranges. On the other hand, in Ca II H intensity

  87. Toshiyuki Hamanaka, Akira Onuki

    Using molecular dynamics simulation we examine dynamics in sheared polycrystal states in a binary mixture containing 10% larger particles in two dimensions. We find large stress fluctuations arising from sliding motions of the particles at the grain boundaries, which occur cooperatively to release the elastic energy stored. These dynamic processes are visual

  88. T. Li, U. Garg, Y. Liu, R. Marks

    The strength distributions of the giant monopole resonance (GMR) have been measured in the even-A Sn isotopes (A=112--124) with inelastic scattering of 400-MeV $α$ particles in the angular range $0^\circ$--$8.5^\circ$. We find that the experimentally-observed GMR energies of the Sn isotopes are lower than the values predicted by theoretical calculations that

  89. R. B. Zhang

    A Schroedinger type equation on the superspace R^{D|2n} is studied, which involves a potential inversely proportional to the negative of the osp(D|2n) invariant &#34;distance&#34; away from the origin. An osp(2,D+1|2n) dynamical supersymmetry for the system is explicitly constructed, and the bound states of the system are shown to form an irreducible highest

  90. Yeh-jong Pan, Chih-wen Weng

    Let $Γ$ denote a distance-regular graph with classical parameters $(D, b, α, β)$ and $D\geq 3$. Assume the intersection numbers $a_1=0$ and $a_2\not=0$. We show $Γ$ is 3-bounded in the sense of the article [D-bounded distance-regular graphs, European Journal of Combinatorics(1997)18, 211-229].

  91. I. N. Krivorotov, N. C. Emley, R. A. Buhrman, D. C. Ralph

    We describe time-domain measurements which provide new information about the large-angle nonlinear dynamics of nanomagnets excited by spin-transfer torque from a spin-polarized current. Sampling-oscilloscope measurements, which average over thousands of experimental time traces, show that the mean reversal time for spin-transfer-driven magnetic switching has

  92. Jianwei Mei, C. N. Pope

    We obtain new non-extremal rotating black hole solutions in maximal five-dimensional gauged supergravity. They are characterised by five parameters, associated with the mass, the two angular momenta, and two independently-specifiable charge parameters. Two of the three charges associated with the U(1)^3 Cartan subgroup of the SO(6) gauge group are equal, whi

  93. M. Upmanyu, H. L. Wang, H. Y. Liang, R. Mahajan

    Coupling between axial and torsional degrees of freedom often modifies the conformation and expression of natural and synthetic filamentous aggregates. Recent studies on chiral single-walled carbon nanotubes and B-DNA reveal a reversal in the sign of the twist-stretch coupling at large strains. The similarity in the response in these two distinct supramolecu

  94. Leonhard Euler

    Translated from the Latin original, &#34;Observationes generales circa series, quarum termini secundum sinus vel cosinus angulorum multiplorum progrediuntur&#34; (1777). E655 in the Enestrom index. Euler looks at the binomial expansion $(1+x)^n$ for $x=\cos ϕ+i\sinϕ$. He does $n=$ positive and negative integers, and $n={1/2}, -{1/2}$, and particular values o

  95. D. A. Garanin

    The phonon-bottleneck problem in the relaxation of two-level systems (spins) via direct phonon processes is considered numerically in the weak-excitation limit where the Schroedinger equation for the spin-phonon system simplifies. The solution for the relaxing spin excitation p(t), emitted phonons n_k(t), etc. is obtained in terms of the exact many-body eige

  96. P. Ao, D. Galas, L. Hood, X. -M. Zhu

    An endogenous molecular-cellular network for both normal and abnormal functions is assumed to exist. This endogenous network forms a nonlinear stochastic dynamical system, with many stable attractors in its functional landscape. Normal or abnormal robust states can be decided by this network in a manner similar to the neural network. In this context cancer i

  97. Yi-Fang Chang

    The present experimental tests have proved high precisely the validity of the Pauli exclusion principle (PEP) in usual cases. The future experiments should be combined widely with various theories of hidden and obvious violation of PEP. Author think that known experiments and theories seem to imply the violation at high energy. Some possible tests have been

  98. M. A. Requena-Torres, J. Martin-Pintado, S. Martin, M. R. Morris

    We present the first detection of complex aldehydes and isomers in three typical molecular clouds located within 200pc of the center of our Galaxy. We find very large abundances of these complex organic molecules (COMs) in the central molecular zone (CMZ), which we attribute to the ejection of COMs from grain mantles by shocks. The relative abundances of the

  99. S. Ramanan, S. K. Bogner, R. J. Furnstahl

    The nonperturbative nature of nucleon-nucleon interactions evolved to low momentum has recently been investigated in free space and at finite density using Weinberg eigenvalues as a diagnostic. This analysis is extended here to the in-medium eigenvalues near the Fermi surface to study pairing. For a fixed value of density and cutoff Lambda, the eigenvalues i

  100. A. Zaidi, L. Vandendorpe

    In this work, we consider a partially cooperative relay broadcast channel (PC-RBC) controlled by random parameters. We provide rate regions for two different situations: 1) when side information (SI) S^n on the random parameters is non-causally known at both the source and the relay and, 2) when side information S^n is non-causally known at the source only.