Research archive

arXiv papers from May 2007

The most recent 100 records published that month. Open any paper for its original abstract, citation metadata, related research, and reading tools.

  1. Sergio D. Corti, Jorge A. Guccione, Juan J. Guccione

    We introduced a braided Sweedler cohomology, which is adequate to work with the H-braided cleft extensions studied in [J. A. Guccione and J. J. Guccione, Theory of braided Hopf crossed products, Journal of Algebra, Vol 261 (2003) 54-101]

  2. J. Angle, E. Aprile, F. Arneodo, L. Baudis

    The XENON10 experiment at the Gran Sasso National Laboratory uses a 15 kg xenon dual phase time projection chamber (XeTPC) to search for dark matter weakly interacting massive particles (WIMPs). The detector measures simultaneously the scintillation and the ionization produced by radiation in pure liquid xenon, to discriminate signal from background down to

  3. Ebrahim Samei

    Let $L^1_\om(G)$ be a Beurling algebra on a locally compact abelian group $G$. We look for general conditions on the weight which allows the vanishing of continuous derivations of $L^1_\om(G)$. This leads us to introducing vector-valued Beurling algebras and considering the translation of operators on them. This is then used to connect the augmentation ideal

  4. Aran Garcia-Bellido

    The results of the first analysis to show evidence for production of single top quarks are presented. Using 0.9 fb-1 of data collected with the D0 detector at the Fermilab Tevatron, the analysis is performed in the electron+jets and muon+jets decay modes, taking special care in modeling the large backgrounds, applying a new powerful b-quark tagging algorithm

  5. Gaston Giribet, Matias Leoni

    We review and study the duality between string theory formulated on a curved exact background (the two dimensional black hole) and string theory in flat space with a tachyon-like potential. We generalize previous results in this subject by discussing a twisted version of the Fateev-Zamolodchikov-Zamolodchikov conjecture. This duality is shown to hold at the

  6. Jiunn-Wei Chen, Donal O'Connell, Andre Walker-Loud

    Mixed action theories with chirally symmetric valence fermions exhibit very desirable features both at the level of the lattice calculations as well as in the construction and implementation of the low energy mixed action effective field theory. In this work we show that when such a mixed action effective field theory is projected onto the valence sector, bo

  7. George S. King, Frank T. Avignone, Christopher E. Cox, Todd W. Hossbach

    A p-type HPGe detector has been segmented by cutting, with a diamond saw, and etching six circumferential grooves through the Li-diffused dead layer. The degree of segmentation was tested with the 88 keV gamma rays from a well-collimated source of 109Cd. The fraction of events, recognized as occurring in more than one segment, and rejected from the energy in

  8. Markku Jaaskelainen, Jaeyoon Jeong, Christopher P. Search

    We study the photo-association of Bose-Einstein condensed atoms into molecules using an optical cavity field. The driven cavity field introduces a new dynamical degree of freedom into the photoassociation process, whose role in determining the stationary behavior has not previously been considered. The semiclassical stationary solutions for the atom and mole

  9. J. P. Roberts

    One of the key motivations for supersymmetry is that it provides a natural candidate for dark matter. For a long time the density of this candidate particle fell within cosmological bounds across much of the SUSY parameter space. However with the precision results of WMAP, it has become apparent that the majority of the SUSY parameter space no longer fits th

  10. Y. J. Wang, Kyoung-Su Im, K. Fezzaa

    we report an ultrafast synchrotron x-ray phase contrast imaging study of the primary breakup mechanism of a coaxial air-assisted water jet. We demonstrate that there exist great similarities in the phenomenology of primary breakup with that of the secondary breakup. Especially, a membrane-mediated breakup mechanism dominates the breakup process for a wide ra

  11. Inhwa Jung, Matthew Pelton, Richard Piner, Dmitriy A. Dikin

    A simple optical method is presented for identifying and measuring the effective optical properties of nanometer-thick, graphene-based materials, based on the use of substrates consisting of a thin dielectric layer on silicon. High contrast between the graphene-based materials and the substrate is obtained by choosing appropriate optical properties and thick

  12. Maor Rosenberg

    We show that Py-Calabi quasi-morphism on the group of Hamiltonian diffeomorphisms of surfaces of higher genus gives rise to a quasi-state.

  13. M. J. Pflaum, H. B. Posthuma, X. Tang, H. -H. Tseng

    In this paper we study the Hochschild cohomology ring of convolution algebras associated to orbifolds, as well as their deformation quantizations. In the first case the ring structure is given in terms of a wedge product on twisted polyvectorfields on the inertia orbifold. After deformation quantization, the ring structure defines a product on the cohomology

  14. Marko A. Rodriguez, Johan Bollen

    Semantic network research has seen a resurgence from its early history in the cognitive sciences with the inception of the Semantic Web initiative. The Semantic Web effort has brought forth an array of technologies that support the encoding, storage, and querying of the semantic network data structure at the world stage. Currently, the popular conception of

  15. Eran Lebanon, P. Coleman

    We discuss how Anderson's ideas of nominal and real valence can be incorporated into the current discussion of heavy electron quantum criticality. In the heavy electron phase, the nominal valence of a screened magnetic ion differs from its real valence by one unit. We identify this discrepancy with the formation of a positively charged background we call the

  16. A. P. Balachandran, A. R. Queiroz, A. M. Marques, P. Teotonio-Sobrinho

    Quantum field theories (QFT's) on noncommutative spacetimes are currently under intensive study. Usually such theories have world sheet noncommutativity. In the present work, instead, we study QFT's with commutative world sheet and noncommutative target space. Such noncommutativity can be interpreted in terms of twisted statistics and is related to earlier w

  17. Heiko Bauke, David Sherrington

    In this contribution we introduce local attachment as an universal network-joining protocol for peer-to-peer networks, social networks, or other kinds of networks. Based on this protocol nodes in a finite-size network dynamically create power-law connectivity distributions. Nodes or peers maintain them in a self-organized statistical way by incorporating loc

  18. Louis H. Kauffman, Samuel J. Lomonaco,

    Let K be a 3-stranded knot (or link), and let L denote the number of crossings in K. Let $\epsilon_{1}$ and $\epsilon_{2}$ be two positive real numbers such that $\epsilon_{2}$ is less than or equal to 1. In this paper, we create two algorithms for computing the value of the Jones polynomial of K at all points $t=exp(i\phi)$ of the unit circle in the complex

  19. S. Koposov, J. T. A. de Jong, V. Belokurov, H. -W. Rix

    We report the discovery of two extremely low luminosity globular clusters in the Milky Way Halo. These objects were detected in the Sloan Digital Sky Survey Data Release 5 and confirmed with deeper imaging at the Calar Alto Observatory. The clusters, Koposov 1 and Koposov 2, are located at $\sim 40-50$ kpc and appear to have old stellar populations and lumin

  20. M. Dzero, P. Coleman

    We outline key elements of a theory that accounts for anomalous properties of the PuCoGa$_5$ and PuRhGa$_5$ compounds as a consequence of a two-body interference between two Kondo screening channels. Virtual valence fluctuations of the magnetic Pu configurations create two conduction channels of different symmetry. Using the symplectic large-N approach, we a

  21. E. A. Leicht, Gavin Clarkson, Kerby Shedden, M. E. J. Newman

    In this paper we examine a number of methods for probing and understanding the large-scale structure of networks that evolve over time. We focus in particular on citation networks, networks of references between documents such as papers, patents, or court cases. We describe three different methods of analysis, one based on an expectation-maximization algorit

  22. Daisuke Kawata, Renyue Cen, Luis C. Ho

    A significant fraction of nearby elliptical galaxies are known to have high density gas disks in their circumnuclear (CN) region (0.1 to a few kpc). Yet, ellipticals, especially luminous ones, show little signs of recent star formation (SF). To investigate the possible cause of the dearth of SF in these systems, we study the gravitational stability of CN gas

  23. Anna Urbanska

    In this paper we propose several strategies for the exact computation of the determinant of a rational matrix. First, we use the Chinese Remaindering Theorem and the rational reconstruction to recover the rational determinant from its modular images. Then we show a preconditioning for the determinant which allows us to skip the rational reconstruction proces

  24. Eric F. Bell, Daniel B. Zucker, Vasily Belokurov, Sanjib Sharma

    We have used data from the Sloan Digital Sky Survey (SDSS) Data Release 5 to explore the overall structure and substructure of the stellar halo of the Milky Way using about 4 million color-selected main sequence turn-off stars. We fit oblate and triaxial broken power-law models to the data, and found a `best-fit' oblateness of the stellar halo 0.5<c/a<0.8, a

  25. Takuro Abe, Yasuhide Numata

    We introduce a concept of multiplicity lattices of 2-multiarrangements, determine the combinatorics and geometry of that lattice, and give a criterion and method to construct a basis for derivation modules effectively.

  26. Yehuda Hoffman, Emilio Romano-Diaz, Isaac Shlosman, Clayton Heller

    The evolution of the phase-space density profile in dark matter (DM) halos is investigated by means of constrained simulations, designed to control the merging history of a given DM halo. Halos evolve through a series of quiescent phases of a slow accretion intermitted by violent events of major mergers. In the quiescent phases the density of the halo closel

  27. G. Cristiani, C. G. Giménez de Castro, M. L. Luoni, C. H. Mandrini

    We analyse the 30 October, 2004, X1.2/SF solar event that occurred in AR 10691 (N13 W18) at around 11:44 UT. Observations at 212 and 405 GHz of the Solar Submillimeter Telescope (SST), with high time resolution (5 ms), show an intense impulsive burst followed by a long-lasting thermal phase. EUV images from the Extreme Ultraviolet Imaging Telescope (SOHO/EIT

  28. Magdalena Anna Pelc

    The motion of particles, where the particles: electrons, ions in microtubules or migrated peoples can be described as the superposition of diffusion and ordered waves. In this paper it is shown that the master equation for transport processes can be formulated as the time delayed hyperbolic partial equation. The equation describes the processes with memory.

  29. Yi-Zhong Fan, Tsvi Piran

    We present self consistent calculations of Synchrotron self Compton (SSC) radiation that takes place within the afterglow blast wave and External inverse Compton (EIC) radiation that takes place when flare photons (produced by an internal process) pass through the blast wave. We show that if our current interpretations of the Swift XRT data are correct, ther

  30. Silvio R. Dahmen

    One of the less known facets of Ludwig Boltzmann was that of an advocate of Aviation, one of the most challenging technological problems of his times. Boltzmann followed closely the studies of pioneers like Otto Lilienthal in Berlin, and during a lecture on a prestigious conference he vehemently defended further investments in the area. In this article I dis

  31. Yang Bai, JiJi Fan, Zhenyu Han

    We construct a calculable model of electroweak symmetry breaking in which the Higgs doublet emerges from the meta-stable SUSY breaking sector as a pseudo Nambu-Goldstone boson. The Higgs boson mass is further protected by the little Higgs mechanism, and naturally suppressed by a two-loop factor from the SUSY breaking scale of 10 TeV. Gaugino and sfermion mas

  32. Xian Zhong Zheng, Herve Dole, Eric F. Bell, Emeric Le Floc'h

    We analyze the infrared (IR) spectral energy distributions (SEDs) for 10micron < lambda(rest) < 100micron for ~600 galaxies at z~0.7 in the extended Chandra Deep Field South by stacking their Spitzer 24, 70 and 160micron images. We place interesting constraints on the average IR SED shape in two bins: the brightest 25% of z~0.7 galaxies detected at 24micron,

  33. Sebastian Eggert, Olav F. Syljuasen, Fabrizio Anfuso, Markus Andres

    The study of impurities in antiferromagnets is of considerable interest in condensed matter physics. In this paper we address the elementary question of the effect of vacancies on the orientation of the surrounding magnetic moments in an antiferromagnet. In the presence of a magnetic field, alternating magnetic moments are induced, which can be described by

  34. A. V. Shytov, M. I. Katsnelson, L. S. Levitov

    Screening of charge impurities in graphene is analyzed using the exact solution for vacuum polarization obtained from the massless Dirac-Kepler problem. For the impurity charge below certain critical value no density perturbation is found away from the impurity, in agreement with the linear response theory result. For supercritical charge, however, the polar

  35. Valentino R. Cooper, Karen Johnston, Karin M. Rabe

    The effect of intermixing at the interface of short period PbTiO$_3$/SrTiO$_3$ superlattices is studied using first-principles density functional theory. The results indicate that interfacial intermixing significantly enhances the polarization within the superlattice. This enhancement is directly related to the off-centering of Pb and Sr cations and can be e

  36. Wang Yao, Di Xiao, Qian Niu

    Inversion symmetry breaking allows contrasted circular dichroism in different k-space regions, which takes the extreme form of optical selection rules for interband transitions at high symmetry points. In materials where band-edges occur at noncentral valleys, this enables valley dependent interplay of electrons with light of different circular polarizations

  37. W. Chen, H. Lu

    We demonstrate that the general (A)dS-Kerr-NUT solutions in D dimensions with ([D/2], [(D+1)/2]) signature admit [D/2] linearly-independent, mutually-orthogonal and affinely-parameterised null geodesic congruences. This enables us to write the metrics in a multi-Kerr-Schild form, where the mass and all of the NUT parameters enter the metrics linearly. In the

  38. Axel Krause, Enrico Pajer

    We investigate the embedding of brane anti-brane inflation into a concrete type IIB string theory compactification with all moduli fixed. Specifically, we are considering a D3-brane, whose position represents the inflaton $\phi$, in a warped conifold throat in the presence of supersymmetrically embedded D7-branes and an anti D3-brane localized at the tip of

  39. Ilya Kapovich, Paul Schupp

    We compare the random group model of Gromov and the model of generic groups of Arzhantseva and Ol'shanskii.

  40. M. E. McBriarty, P. Kumar, G. R. Stewart, B. Andraka

    Specific heat, dc- and ac-magnetic susceptibility are reported for a large single crystal of PrOs$_4$Sb$_{12}$ and, after grinding, its powder. The room temperature effective paramagnetic moment of the crystal was consistent with the Pr$^{3+}$ ionic configuration and full occupancy of the Pr-sublattice. The crystal showed two distinct anomalies in the specif

  41. Pankaj Mehta, Natan Andrei

    Nonequilibrium steady-state currents, unlike their equilibrium counterparts, continuously dissipate energy into their physical surroundings leading to entropy production and time-reversal symmetry breaking. This letter discusses these issues in the context of quantum impurity models driven out of equilibrium by attaching the impurity to leads at different ch

  42. T. Adams

    Numerous searches for new phenomena have been carried out using data from proton-antiproton collisions at Fermilab's Tevatron. Final states with leptons give signatures which are relatively unique and generally have small backgrounds. We present many of the latest results from the CDF and D0 collaborations from 0.4-1.2 fb^-1 of data. Topics include supersymm

  43. Mikhail N. Smolyakov, Igor P. Volobuev

    We present a model describing a single brane with tension embedded into a five-dimensional space-time with compact extra dimension, which can be easily stabilized. We examine the linearized gravity in the model and obtain an expression for the four-dimensional Planck mass on the brane in terms of the model parameters. It is also shown that the scalar sector

  44. Julio G. Dix, Cesar A. Terrero-Escalante

    This article concerns the stability of a model for mass-spring systems with positive damping and negative stiness. It is well known that when the coefficients are frozen in time the system is unstable. Here we find conditions on the variable cofficients to prove stability. In particular, we disprove the believe that if the eigenvalues of the system change sl

  45. Chuanwei Zhang, Sumanta Tewari, S. Das Sarma

    We propose and analyze a probabilistic scheme to entangle two spatially separated topological qubits in a $p_{x}+ip_{y}$ superfluid using controlled collisions between atoms in movable dipole traps and unpaired atoms inside vortex cores in the superfluid. We discuss how to test the violation of Bell's inequality with the generated entanglement. A set of univ

  46. Steen H. Hansen, Rocco Piffaretti

    The Universe contains approximately 6 times more dark matter than normal baryonic matter, and a directly observed fundamental difference between dark matter and baryons would both be significant for our understanding of dark matter structures and provide us with information about the basic characteristics of the dark matter particle. We discuss one distincti

  47. H. Pierre Noyes

    Biology is considered here as an "emergent science" in the sense of Anderson and of Laughlin and Pines. It is demonstrated that a straightforward mathematical definition of "biological system" is useful in showing how biology differs in structure from the lower levels in Anderson's "More is Different" hierarchy. Using cells in a chemostat as a paradigmatic e

  48. Daniel Lemire, Owen Kaser

    Many applications use sequences of n consecutive symbols (n-grams). Hashing these n-grams can be a performance bottleneck. For more speed, recursive hash families compute hash values by updating previous values. We prove that recursive hash families cannot be more than pairwise independent. While hashing by irreducible polynomials is pairwise independent, ou

  49. D. R. Boito, B. El-Bennich, B. Loiseau, O. Leitner

    We describe the $\pi\pi$ $S$-wave in $D^+ \to\pi^+ \pi^- \pi^+$ decays using a unitary model for the $\pi\pi$ Final State Interactions (FSI). The three body decay is treated as a quasi two-body process where, at the weak vertex, the D meson decays into a resonance and a pion. The weak part of the decay amplitude is evaluated using the effective weak Hamilton

  50. R. P. Chaudhury, F. Yen, C. R. dela Cruz, B. Lorenz

    MnWO4 has attracted attention because of its ferroelectric property induced by frustrated helical spin order. Strong spin-lattice interaction is necessary to explain ferroelectricity associated with this type of magnetic order.We have conducted thermal expansion measurements along the a, b, c axes revealing the existence of strong anisotropic lattice anomali

  51. Béla Csaba, András S. Pluhár

    We study the on-line minimum weighted bipartite matching problem in arbitrary metric spaces. Here, $n$ not necessary disjoint points of a metric space $M$ are given, and are to be matched on-line with $n$ points of $M$ revealed one by one. The cost of a matching is the sum of the distances of the matched points, and the goal is to find or approximate its min

  52. Arend Hintze, Christoph Adami

    Biological networks have evolved to be highly functional within uncertain environments while remaining extremely adaptable. One of the main contributors to the robustness and evolvability of biological networks is believed to be their modularity of function, with modules defined as sets of genes that are strongly interconnected but whose function is separabl

  53. A. B. Arbuzov, L. A. Glinka, V. N. Pervushin

    A version of the Standard Model is considered, where the electroweak symmetry breaking is provided by cosmological initial data given for the zeroth Fourier harmonic of the Higgs field $<\phi>$. The initial data symmetry breaking mechanism removes the Higgs field contribution to the vacuum energy density, possible creation of monopoles, and tachion behavior

  54. Anatoly E. Dementyev, David G. Cory, Chandrasekhar Ramanathan

    In a dynamic nuclear polarization experiment on a 40 mM solution of 4-amino-TEMPO in a 40:60 water/glycerol mixture, we have observed that the bulk dipolar reservoir is cooled to a spin temperature of 15.5 micro-K, following microwave irradiation for 800 s. This is significantly cooler than the 35 mK spin temperature of the Zeeman reservoir. Equilibration of

  55. B. Davids, A. Gruzinov, B. K. Jennings

    This paper suffers from conceptual difficulties and unjustified approximations that render its conclusions dubious.

  56. Atsushi Nishizawa, Seiji Kawamura, Masa-aki Sakagami

    There exists the standard quantum limit (SQL), derived from Heisenberg's uncertainty relation, in the sensitivity of laser interferometer gravitational-wave detectors. However, in the context of a full quantum-mechanical approach, SQL can be overcome using the correlation of shot noise and radiation-pressure noise. So far, signal recycling, which is one of t

  57. A. Mirizzi, D. Montanino, P. D. Serpico

    Neutrino oscillation experiments and direct bounds on absolute masses constrain neutrino mass differences to fall into the microwave energy range, for most of the allowed parameter space. As a consequence of these recent phenomenological advances, older constraints on radiative neutrino decays based on diffuse background radiations and assuming strongly hier

  58. Hael Collins, R. Holman

    This article examines how a breakdown of a locally Lorentz invariant, point-like description of nature at tiny space-time intervals would translate into a distinctive set of signals in the primordial power spectrum generated by inflation. We examine the leading irrelevant operators that are consistent with the spatial translations and rotations of a preferre

  59. Laur Jarv, Piret Kuusk, Margus Saal

    We consider the correspondence between the Jordan frame and the Einstein frame descriptions of scalar-tensor theory of gravitation. We argue that since the redefinition of the scalar field is not differentiable at the limit of general relativity the correspondence between the two frames is lost at this limit. To clarify the situation we analyse the dynamics

  60. A. M. Lionetto

    We study the effects of a non thermal neutralino production, due to the late decay in the early universe of a single modulus field, in the context of the deflected anomaly mediated scenario. In the regime in which the average number of neutralino produced in each modulus decaying process is $\bar{N}_{{\rm LSP}}\ll 1$ also models with a thermal relic density

  61. A. G. Gibb, M. G. Hoare

    We present high-resolution observations made with the Very Large Array (VLA) in its A configuration at frequencies between 5 and 43 GHz of a sample of five massive young stellar objects (YSOs): LkHa101, NGC2024-IRS2, S106-IR, W75N and S140-IRS1. The resolution varied from 0.04 arcsec (at 43 GHz) to 0.5 arcsec (at 5 GHz), corresponding to a linear resolution

  62. Tim Austin, Assaf Naor, Alain Valette

    We show that the cyclic lamplighter group $C_2 \bwr C_n$ embeds into Hilbert space with distortion ${\rm O}(\sqrt{\log n})$. This matches the lower bound proved by Lee, Naor and Peres in \cite{LeeNaoPer}, answering a question posed in that paper. Thus the Euclidean distortion of $C_2 \bwr C_n$ is $\Theta(\sqrt{\log n})$. Our embedding is constructed explicit

  63. Marius Zimand

    The randomness rate of an infinite binary sequence is characterized by the sequence of ratios between the Kolmogorov complexity and the length of the initial segments of the sequence. It is known that there is no uniform effective procedure that transforms one input sequence into another sequence with higher randomness rate. By contrast, we display such a un

  64. James D. Lewis, Shuji Saito

    Let $X$ be a projective algebraic manifold and let $CH^r(X)$ be the Chow group of algebraic cycles of codimension $r$ on $X$, modulo rational equivalence. Working with a candidate Bloch-Beilinson filtration $\{F^{\nu}\}_{\nu\geq 0}$ on $CH^r(X)\otimes {\Bbb Q}$ due to the second author, we construct a space of arithmetic Hodge theoretic invariants $\nabla J^

  65. Zh. Hao, G. M. von Hippel, R. R. Horgan, Q. J. Mason

    The effects of unquenching on the perturbative improvement coefficients in the Symanzik action are computed within the framework of L\"uscher-Weisz on-shell improvement. We find that the effects of quark loops are surprisingly large, and their omission may well explain the scaling violations observed in some unquenched studies.

  66. Frederic P. Schuller, Mattias N. R. Wohlfarth

    We provide further crucial support for a refined, area metric structure of spacetime. Based on the solution of conceptual issues, such as the consistent coupling of fermions and the covariant identification of radiation fields on area metric backgrounds, we show that the radiation-dominated epoch of area metric cosmology is equivalent to that epoch in standa

  67. André LeClair, Matthias Neubert

    We study a model of N-component complex fermions with a kinetic term that is second order in derivatives. This symplectic fermion model has an Sp(2N) symmetry, which for any N contains an SO(3) subgroup that can be identified with rotational spin of spin-1/2 particles. Since the spin-1/2 representation is not promoted to a representation of the Lorentz group

  68. Tobias M. Raufer

    The MINOS long baseline experiment has been collecting neutrino beam data since March 2005 and has accumulated 3 x 10^{20} protons-on-target (POT) to date. MINOS uses Fermilab's NuMI neutrino beam which is measured by two steel-scintillator tracking calorimeters, one at Fermilab and the other 735 km downstream, in northern Minnesota. By observing the oscilla

  69. Tanju Gleisberg, Stefan Hoeche, Frank Krauss, Radoslaw Matyszkiewicz

    Some features of modern simulation tools for high-energy physics are reviewed.

  70. Peter F. Lichtenwalner, Donald A. Sofge

    An integrated and automated smart structures approach for structural health monitoring is presented, utilizing an array of piezoelectric transducers attached to or embedded within the structure for both actuation and sensing. The system actively interrogates the structure via broadband excitation of multiple actuators across a desired frequency range. The st

  71. Stefan Höche, Frank Krauss, Thomas Teubner

    A Markovian Monte Carlo algorithm for multi-parton production in the high-energy limit is proposed and the matching with unintegrated parton densities is discussed.

  72. Khin Maung Maung, John W. Norbury, Trina Coleman

    It is shown that a relativistic multiple scattering theory for hadron-nucleus scattering can be consistently formulated in four-dimensions in the context of meson exchange. We give a multiple scattering series for the optical potential and discuss the differences between the relativistic and non-relativistic versions. We develop the relativistic multiple sca

  73. Adam Falkowski, Stefan Pokorski, J. P. Roberts

    We study scattering of the electroweak gauge bosons in 5D warped models. Within two different models we determine the precise manner in which the Higgs boson and the vector resonances ensure the unitarity of longitudinal vector boson scattering. We identify three separate scales that determine the dynamics of the scattering process in all cases. For a quite

  74. Carlos Barcelo, Gil Jannes

    Many condensed matter systems are such that their collective excitations at low energies can be described by fields satisfying equations of motion formally indistinguishable from those of relativistic field theory. The finite speed of propagation of the disturbances in the effective fields (in the simplest models, the speed of sound) plays here the role of t

  75. Gennady V. Kovalev

    The volume capture in classical relativistic mechanics is considered as a scattering process for the high energy charged particles in a field with no central or mirror symmetry. The parameters of volume capture for potentials with smooth variable curvature are received and analyzed.

  76. M. Spaans, R. Meijerink

    Based on its strong CO+ emission it is argued that the M 82 star-burst galaxy is exposed to a combination of FUV and X-ray radiation. The latter is likely to be the result of the star-burst superwind, which leads to diffuse thermal emission at ~0.7 keV, and a compact hard, 2-10 keV, source (but not an AGN). Although a photon-dominated region (FUV) component

  77. J. Niset, N. J. Cerf

    The entanglement content of superpositions of quantum states is investigated based on a measure called {\it concurrence}. Given a bipartite pure state in arbitrary dimension written as the quantum superposition of two other such states, we find simple inequalities relating the concurrence of the state to that of its components. We derive an exact expression

  78. Peter Pflug, Viet-Anh Nguyen

    Let $D$ and $G$ be copies of the open unit disc in $\C,$ let $A$ (resp. $B$) be a measurable subset of $\partial D$ (resp. $\partial G$), let $W$ be the 2-fold cross $\big((D\cup A)\times B\big)\cup \big(A\times(B\cup G)\big),$ and let $M$ be a relatively closed subset of $W.$ Suppose in addition that $A$ and $B$ are of positive one-dimensional Lebesgue meas

  79. A. J. T. Poelarends, F. Herwig, N. Langer, A. Heger

    We study the late evolution of solar metallicity stars in the transition region between white dwarf formation and core collapse. This includes the super-asymptotic giant branch (super-AGB, SAGB) stars, which have massive enough cores to ignite carbon burning and form an oxygen-neon (ONe) core. The most massive SAGB stars have cores that may grow to the Chand

  80. Fernando Peruani, Luis G. Morelli

    We study general aspects of active motion with fluctuations in the speed and the direction of motion in two dimensions. We consider the case in which fluctuations in the speed are not correlated to fluctuations in the direction of motion, and assume that both processes can be described by independent characteristic time-scales. We show the occurrence of a co

  81. Manjari Bagchi, Jishnu Dey, Mira Dey, Taparati Gangopadhyay

    High energy density ($\eps$) and temperature (T) links general relativity and hydrodynamics leading to a lower bound for the ratio of shear viscosity ($\eta$) and entropy density ($s$). We get the interesting result that the bound is saturated in the simple model for quark matter that we use for strange stars at the surface for $T \sim 80 MeV$. At this $T$ w

  82. D. Clarke, G. -W. Chern, O. A. Tretiakov, O. Tchernyshyov

    In this report we demonstrate a simple model for the motion of a vortex domain wall in a ferromagnetic strip of submicron width under the influence of an external magnetic field. The model exhibits three distinct dynamical regimes. In a viscous regime at low fields the wall moves rigidly with a velocity proportional to the field. Above a critical field the m

  83. Donald Marolf, Simon F. Ross

    For scalar fields in AdS with masses slightly above the Breitenlohner-Freedman bound, appropriate non-local boundary conditions can define a unitary theory. Such boundary conditions correspond to non-local deformations of the dual CFT, and generate a non-local renormalization-group flow. Nevertheless, a bulk analysis suggests that certain such flows lead to

  84. Nils Hasselmann, Andreas Sinner, Peter Kopietz

    We discuss the order parameter correlation function in the vicinity of continuous phase transitions using a two-parameter scaling form G(k) = k_c^{-2} g(k\xi,k/k_c), where k is the wave-vector, \xi is the correlation length, and the interaction-dependent non-universal momentum scale k_c remains finite at the critical fixed point. The correlation function des

  85. Rohta Takahashi

    Equations of fully general relativistic radiation hydrodynamics in Kerr space-time are derived. While the interactions between matter and radiation are introduced in the comoving frame, the derivatives used when describing the global evolutions of both the matter and the radiation are given in the Boyer-Lindquist frame (BLF) which is a frame fixed to the coo

  86. Leonhard Euler

    This is a translation from the Latin original, "De valoribus integralium a termino variabilis x=0 usque ad x=infinity extensorum" (1781). This is E675 in the Enestrom index. Euler wants to find the location of the end point of a clothoid, a type of spiral. He proves some general results about the gamma function.

  87. Andrew Bartholomew, Roger Fenn, Naoko Kamada, Seiichi Kamada

    This paper extends the construction of invariants for virtual knots to virtual long knots and introduces two new invariant modules of virtual long knots. Several interesting features are described that distinguish virtual long knots from their classical counterparts with respect to their symmetries and the concatenation product.

  88. Thierry Emonet, Philippe Cluzel

    Bacterial chemotaxis in Escherichia coli is a canonical system for the study of signal transduction. A remarkable feature of this system is the coexistence of precise adaptation in population with large fluctuating cellular behavior in single cells (Korobkova et al. 2004, Nature, 428, 574). Using a stochastic model, we found that the large behavioral variabi

  89. H. D. Zeh

    The concept of time as used in various applications and interpretations of quantum theory is briefly reviewed.

  90. O. A. Tretiakov, D. Clarke, Gia-Wei Chern, Ya. B. Bazaliy

    We express dynamics of domain walls in ferromagnetic nanowires in terms of collective coordinates generalizing Thiele's steady-state results. For weak external perturbations the dynamics is dominated by a few soft modes. The general approach is illustrated on the example of a vortex wall relevant to recent experiments with flat nanowires. A two-mode approxim

  91. M. W. Haverkort, A. Tanaka, L. H. Tjeng, G. A. Sawatzky

    In a recent publication Larson \textit{et al.} reported remarkably clear $d$-$d$ excitations for NiO and CoO measured with x-ray energies well below the transition metal $K$ edge. In this letter we demonstrate that we can obtain an accurate quantitative description based on a local many body approach. We find that the magnitude of $\vec{q}$ can be tuned for

  92. Carlo Nipoti, Pasquale Londrillo, Luca Ciotti

    We present the results of N-body simulations of dissipationless galaxy merging in Modified Newtonian Dynamics (MOND). For comparison, we also studied Newtonian merging between galaxies embedded in dark matter halos, with internal dynamics equivalent to the MOND systems. We found that the merging timescales are significantly longer in MOND than in Newtonian g

  93. Paul G. Evans, Eric D. Isaacs, Gabriel Aeppli, Zhonghou Cai

    Magnetic x-ray diffraction combined with x-ray focusing optics is used to image individual antiferromagnetic spin density wave domains in a chromium single crystal at the micron scale. The cross section for non-resonant magnetic x-ray scattering depends on the antiferromagnetic modulation vector and spin polarization direction and allows these quantities to

  94. Diego Calzolari, Giovanni Paternostro, Patrick L. Harrington, Carlo Piermarocchi

    Selective control in a population is the ability to control a member of the population while leaving the other members relatively unaffected. The concept of selective control is developed using cell death or apoptosis in heterogeneous cell populations as an example. Apoptosis signaling in heterogeneous cells is described by an ensemble of gene networks with

  95. Declan A. Diver, Luis F. A. Teodoro

    This letter concentrates on the non-equilibrium evolution of magnetic field structures at the onset of recombination, when the charged particle current densities decay as neutrals are formed. We consider the effect that a decaying magnetic flux has on the acceleration of particles via the transient induced electric field. Since the residual charged-particle

  96. L. Pezze', A. Smerzi

    We show that the phase sensitivity $\Delta \theta$ of a Mach-Zehnder interferometer fed by a coherent state in one input port and squeezed-vacuum in the other one is i) independent from the true value of the phase shift and ii) can reach the Heisenberg limit $\Delta \theta \sim 1/N_T$, where $N_T$ is the average number of particles of the input states. We al

  97. Auguste Ndoutoume-Ndong, Danielle Rojas-Rousse

    Ni\'eb\'e is a food leguminous plant cultivated in tropical Africa for its seeds rich in proteins. The main problem setted by its production is the conservation of harvests. In the fields as in the stocks, the seeds are destroyed by pests (bruchids). These bruchids are always associated with several entomophagous species of hymenoptera. Four entomophagous sp

  98. Vishnu Jejjala, Michael Kavic, Djordje Minic

    Following our recent work on the cosmological constant problem, in this letter we make a specific proposal regarding the fine structure (i.e., the spectrum) of dark energy. The proposal is motivated by a deep analogy between the blackbody radiation problem, which led to the development of quantum theory, and the cosmological constant problem, which we have r

  99. Feng-Li Lin, Toshihiro Matsuo, Dan Tomino

    Motivated by the possibility of formulating a strings/black hole correspondence in AdS space, we extract the Hagedorn behavior of thermal AdS_3 bosonic string from 1-loop partition function of SL(2,R) WZW model. We find that the Hagedorn temperature is monotonically increasing as the AdS radius shrinks, reaches a maximum of order of string scale set by the u

  100. M. N. Chernodub, I. E. Kozlov

    We calculate the topological susceptibility of the Yang-Mills vacuum using the field correlator method. Our estimate for the SU(3) gauge group, \chi^{1/4} = 196(7) MeV, is in a very good agreement with the results of recent numerical simulations of the Yang-Mills theory on the lattice.