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Occupy Wall Street YouTube Archive
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12-6-11 9:53pm - #NationalGA FIRST EVER Inter-Occupy General Assembly OWS Occupy DCcc
Topics: ows, IMG, 0075, democcupy
Source: https://www.youtube.com/watch?v=QrAam22n__w&feature=youtube_gdata
NASA Education Gallery
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Center for Space Exploration Technology Research (cSETR) University Research Center Research assistants at the Center for Space Exploration Technology Research prior to a test near White Sands, New Mexico. The PAD Abort test was part of the Orion program served to validate the Orion crew exploration vehicle’s launch abort system.
Source: http://www.nasa.gov/offices/education/programs/national/urc/multimedia/imagegallery/UTEP_2.html
Al Jazeera Creative Commons Repository
by Al Jazeera English
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Taken at 2011-02-03T10:27:55-08:00
Source: http://www.flickr.com/photos/aljazeeraenglish/5416167082
Al Jazeera Creative Commons Repository
by Al Jazeera English
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Taken at 2011-02-13T02:00:27-08:00
Source: http://www.flickr.com/photos/aljazeeraenglish/5444340087
Al Jazeera Creative Commons Repository
by Al Jazeera English
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Taken at 2011-03-01T11:09:54-08:00
Source: http://www.flickr.com/photos/aljazeeraenglish/5490493620
Dryden Image Gallery
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Ron Strong, a SOFIA telescope technician at NASA's Ames Research Center, explains elements of the infrared telescope carried onboard the NASA 747SP Stratospheric Observatory for Infrared Astronomy to visitors of the NASA exhibit at the 2011 Albuquerque International Balloon Fiesta. October 3, 2011 NASA / Jay Levine
Source: http://www.nasa.gov/centers/dryden/multimedia/albuquerque_balloon_fiesta/Levine_5681.html
Exploration Multimedia Gallery
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JSC2011-E-217266 (20 Dec. 2011) A test article that mimics the Orion spacecraft is seen under parachutes Tuesday, Dec. 20, as NASA engineers conducted a drop test above Yuma, Ariz. The Orion team was examining how the spacecraft would land under only two parachutes, instead of the normal three.
Source: http://www.nasa.gov/exploration/systems/mpcv/gallery/parachute_testing/jsc2011e217266.html
NASA Deputy Administrator Lori Garver participates in a Jan. 30 press conference in Herzliya, Israel, as part of the Sixth Annual Ilan Ramon International Space Conference. Sitting at the head tables to answer questions from two dozen Israeli journalists are (left to right) Rona Ramon, Ilan Ramon’s widow, Brig. Gen. Asaf Agmon, who heads the Fisher institute for Air and Space Strategic Studies, Garver, ESA Director General Jean-Jacques Dordain, Israeli Minister of Science and Technology...
Source: http://www.nasa.gov/about/highlights/garver_israel_04.html
NASA Aeronautics Image Gallery
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Jenay Leach (left), a NASA Einstein Fellow, begins to lead students through the main ideas about the science of flight that they'll discover during "It's Not Rocket Science … or Is It?" week at an Alexandria, Va., school. Image credit: NASA/Maria Werries
Source: http://www.nasa.gov/topics/aeronautics/features/imagination_fascination2.html
NASA Education Gallery
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Students were able to visit NASA's Kennedy Space Center's Visitor Center.
Source: http://www.nasa.gov/offices/education/programs/national/nes2/home/visitor-center.html
Stennis Space Center Collection
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In celebration of Black History Month, the Stennis Diversity Council presented "Coffee with Ms. Victoria" on February 16, 20011. Ms. Victoria Webb, a spry 103-year-old native of Pass Christian, was guest speaker. Prograam attendees "eavesdropped" on a kitchen table conversation with Ms. Webb as she shared Black History through the eyes of a centenarian. Sharing coffee with Ms. Webb was close friend, Jeanell Barnes and program moderator, Valli Battle. The program was...
Source: http://www.nasa.gov/centers/stennis/about/organization/odeo/events/2011/bhm-program1.html
Al Jazeera Creative Commons Repository
by Al Jazeera English
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Taken at 2011-02-12T23:19:58-08:00
Source: http://www.flickr.com/photos/aljazeeraenglish/5444337307
NASA Aeronautics Image Gallery
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The tarmac at Joint Base Andrews is crowded with visitors and vehicles during the Joint Services Open House in May near Washington, D.C. Image credit: NASA/Maria Werries
Source: http://www.nasa.gov/topics/aeronautics/features/jsoh4.html
Wikimedia Foundation
by Wikimedia projects editors
web

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This is the full database dump of the Nāhuatl Wiktionary that is generated by the Wikimedia Foundation on October 12, 2011.
Topics: wiki, dumps, data dumps, nahwiktionary, Nāhuatl, Wiktionary
Wikimedia Foundation
by Wikimedia projects editors
web

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This is the full database dump of the Nauru Wikipedia that is generated by the Wikimedia Foundation on September 07, 2011.
Topics: wiki, dumps, data dumps, nawiki, Nauru, Wikipedia
Wikimedia Foundation
web

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This is the full database dump of the Mirandese Wikipedia that is generated by the Wikimedia Foundation on September 01, 2011.
Topics: wiki, dumps, data dumps, mwlwiki, Mirandese, Wikipedia
Wikimedia Foundation
web

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This is the full database dump of the Norwegian Nynorsk Wiktionary that is generated by the Wikimedia Foundation on October 14, 2011.
Topics: wiki, dumps, data dumps, nnwiktionary, Norwegian Nynorsk, Wiktionary
Wikimedia Foundation
by Wikimedia projects editors
web

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This is the full database dump of the Nepali Wikibooks that is generated by the Wikimedia Foundation on October 10, 2011.
Topics: wiki, dumps, data dumps, newikibooks, Nepali, Wikibooks
Wikimedia Foundation
web

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This is the full database dump of the молдовеняскэ Wikipedia that is generated by the Wikimedia Foundation on October 16, 2011.
Topics: wiki, dumps, data dumps, mowiki, молдовеняскэ, Wikipedia
Wikimedia Foundation
web

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This is the full database dump of the Marathi Wiktionary that is generated by the Wikimedia Foundation on September 02, 2011.
Topics: wiki, dumps, data dumps, mrwiktionary, Marathi, Wiktionary
Wikimedia Foundation
by Wikimedia projects editors
web

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This is the full database dump of the Dutch Wikinews that is generated by the Wikimedia Foundation on September 05, 2011.
Topics: wiki, dumps, data dumps, nlwikinews, Dutch, Wikinews
Arxiv.org
by Nikolaos Diamantis; Cormac O'Sullivan
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The Rankin-Cohen bracket of two Eisenstein series provides a kernel yielding products of the periods of Hecke eigenforms at critical values. Extending this idea leads to a new type of Eisenstein series built with a double sum. We develop the properties of these series and their non-holomorphic analogs and show their connection to values of L-functions outside the critical strip.
Source: http://arxiv.org/abs/1009.1067v3
Arxiv.org
by Tiberiu Harko; Zoltán Kovács; Francisco S. N. Lobo
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In the present work, we consider the possibility of observationally testing Ho\v{r}ava gravity by using the accretion disk properties around slowly rotating black holes of the Kehagias-Sfetsos solution in asymptotically flat spacetimes. The energy flux, temperature distribution, the emission spectrum as well as the energy conversion efficiency are obtained, and compared to the standard slowly rotating general relativistic Kerr solution. Comparing the mass accretion in a slowly rotating...
Source: http://arxiv.org/abs/1009.1958v2
Arxiv.org
by Godofredo Iommi; Mike Todd
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We extend the theory of transience to general dynamical systems with no Markov structure assumed. This is linked to the theory of phase transitions. We also provide examples of new kinds of transient behaviour.
Source: http://arxiv.org/abs/1009.2772v2
Arxiv.org
by J. A. de Azcarraga; J. M. Izquierdo
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We study the problem of the infinitesimal deformations of all real, simple, finite-dimensional Filippov (or n-Lie) algebras, considered as a class of n-Leibniz algebras characterized by having an n-bracket skewsymmetric in its n-1 first arguments. We prove that all n>3 simple finite-dimensional Filippov algebras are rigid as n-Leibniz algebras of this class. This rigidity also holds for the Leibniz deformations of the semisimple n=2 Filippov (i.e., Lie) algebras. The n=3 simple FAs, however,...
Source: http://arxiv.org/abs/1009.2709v2
Arxiv.org
by Franz X. Bronold; Rafael L. Heinisch; Johannes Marbach; Holger Fehske
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Plasma walls accumulate electrons more efficiently than ions leading to wall potentials which are negative with respect to the plasma potential. Theoretically, walls are usually treated as perfect absorber for electrons and ions implying perfect sticking of the particles to the wall and infinitely long desorption times for particles stuck to the wall. For electrons we question the perfect absorber model and calculate, specifically for a planar dielectric wall, the electron sticking coefficient...
Source: http://arxiv.org/abs/1009.2897v2
Arxiv.org
by D. J. Chappell; S. Giani; G. Tanner
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Standard methods for describing the intensity distribution of mechanical and acoustic wave fields in the high frequency asymptotic limit are often based on flow transport equations. Common techniques are statistical energy analysis, employed mostly in the context of vibro-acoustics, and ray tracing, a popular tool in architectural acoustics. Dynamical energy analysis makes it possible to interpolate between standard statistical energy analysis and full ray tracing, containing both of these...
Source: http://arxiv.org/abs/1009.3769v2
Arxiv.org
by Ashivni Shekhawat; Stefanos Papanikolaou; Stefano Zapperi; James P. Sethna
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Motivated by recent experiments on the finite temperature Mott transition in VO2 films, we propose a classical coarse-grained dielectric breakdown model where each degree of freedom represents a nanograin which transitions from insulator to metal with increasing temperature and voltage at random thresholds due to quenched disorder. We describe the properties of the resulting non-equilibrium metal-insulator transition and explain the universal characteristics of the resistance jump distribution....
Source: http://arxiv.org/abs/1009.4735v3
Arxiv.org
by James Owen Weatherall
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A theorem due to Bob Geroch and Pong Soo Jang ["Motion of a Body in General Relativity." Journal of Mathematical Physics 16(1), (1975)] provides the sense in which the geodesic principle has the status of a theorem in General Relativity (GR). Here we show that a similar theorem holds in the context of geometrized Newtonian gravitation (often called Newton-Cartan theory). It follows that in Newtonian gravitation, as in GR, inertial motion can be derived from other central principles of...
Source: http://arxiv.org/abs/1010.0379v3
Arxiv.org
by Ariel Balter; Alexandre Tartakovsky
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We describe a new, microscopic model for diffusion that captures diffusion induced fluctuations at scales where the concept of concentration gives way to discrete particles. We show that in the limit as the number of particles $N \to \infty$, our model is equivalent to the classical stochastic diffusion equation (SDE). We test our new model and the SDE against Langevin dynamics in numerical simulations, and show that our model successfully reproduces the correct ensemble statistics, while the...
Source: http://arxiv.org/abs/1010.0719v4
Arxiv.org
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Even tiny lepton flavor violation (LFV) due to some New Physics is able to alter the conditions inside a collapsing supernova core and probably to facilitate the explosion. LFV emerges naturally in a See-Saw type II model of neutrino mass generation. Experimentally LFV is constrained by rare lepton decay searches. In particular, strong bounds are imposed on the mu->eee branching ratio and on the mu-e conversion probability in muonic gold. Currently the mu->e gamma decay is under...
Source: http://arxiv.org/abs/1010.1694v2
Arxiv.org
by Sylvain Billiard; Viet Chi Tran
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Disentangling the processes leading populations to extinction is a major topic in ecology and conservation biology. The difficulty to find a mate in many species is one of these processes. Here, we investigate the impact of self-incompatibility in flowering plants, where several inter-compatible classes of individuals exist but individuals of the same class cannot mate. We model pollen limitation through different relationships between mate availability and fertilization success. After deriving...
Source: http://arxiv.org/abs/1010.2984v3
Arxiv.org
by Malte Vogl; Gernot Schaller; Tobias Brandes
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We theoretically study cooperative effects in the steady-state transmission of photons through a medium of $N$ radiators. Using methods from quantum transport, we find a cross-over in scaling from $N$ to $N^2$ in the current and even higher powers of $N$ in the higher cumulants of the photon counting statistics as a function of the tunable source occupation. The effect should be observable for atoms confined within a nano-cell with a pumped optical cavity as photon source.
Source: http://arxiv.org/abs/1010.4416v3
Arxiv.org
by R. N. Caldeira Costa; Marika Taylor
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Deformation of any d-dimensional conformal field theory by a constant null source for a vector operator of dimension (d + z -1) is exactly marginal with respect to anisotropic scale invariance, of dynamical exponent z. The holographic duals to such deformations are AdS plane waves, with z=2 being the Schrodinger geometry. In this paper we explore holography for such chiral scale-invariant models. The special case of z=0 can be realized with gravity coupled to a scalar, and is of particular...
Source: http://arxiv.org/abs/1010.4800v2
Arxiv.org
by Chenxu He; Peter Petersen; William Wylie
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In this paper we take the perspective introduced by Case-Shu-Wei of studying warped product Einstein metrics through the equation for the Ricci curvature of the base space. They call this equation on the base the $m$-Quasi Einstein equation, but we will also call it the $(\lambda,n+m)$-Einstein equation. In this paper we extend the work of Case-Shu-Wei and some earlier work of Kim-Kim to allow the base to have non-empty boundary. This is a natural case to consider since a manifold without...
Source: http://arxiv.org/abs/1010.5488v2
Arxiv.org
by Julio Guerrero; Francisco F. López-Ruiz; Victor Aldaya; Francisco Cossio
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Different families of states, which are solutions of the time-dependent free Schr\"odinger equation, are imported from the harmonic oscillator using the Quantum Arnold Transformation introduced in a previous paper. Among them, infinite series of states are given that are normalizable, expand the whole space of solutions, are spatially multi-localized and are eigenstates of a suitably defined number operator. Associated with these states new sets of coherent and squeezed states for the free...
Source: http://arxiv.org/abs/1010.5525v3
Arxiv.org
by Charlie Conroy; Abraham Loeb; David Spergel
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The conjecture that the ancient globular clusters (GCs) formed at the center of their own dark matter halos was first proposed by Peebles (1984), and has recently been revived to explain the puzzling abundance patterns observed within many GCs. In this paper we demonstrate that the outer stellar density profile of isolated GCs is very sensitive to the presence of an extended dark halo. The GCs NGC 2419, located at 90 kpc from the center of our Galaxy, and MGC1, located at ~200 kpc from the...
Source: http://arxiv.org/abs/1010.5783v2
Arxiv.org
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Relations among integrals of logarithms, polylogarithms and Euler sums are presented. A unifying element being the introduction of Nielsen's generalized polylogarithms.
Source: http://arxiv.org/abs/1010.6229v5
Arxiv.org
by Jaiseung Kim; Pavel Naselsky
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We have investigated the angular correlation in the recent CMB data. In addition to the known large-angle correlation anomaly, we find the lack of correlation at small angles with high statistical significance. We have investigated various non-cosmological contamination and additionally WMAP team's simulated data. However, we have not found a definite cause. In the angular power spectrum of WMAP data, there exist anomalous odd-parity preference at low multipoles. Noting the equivalence between...
Source: http://arxiv.org/abs/1011.0377v6
Arxiv.org
by Florian Beyer; Philippe G. LeFloch
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We introduce a new class of singular partial differential equations, referred to as the second-order hyperbolic Fuchsian systems, and we investigate the associated initial value problem when data are imposed on the singularity. First, we establish a general existence theory of solutions with asymptotic behavior prescribed on the singularity, which relies on a new approximation scheme, suitable also for numerical purposes. Second, this theory is applied to the (vacuum) Einstein equations for...
Source: http://arxiv.org/abs/1011.0270v2
Arxiv.org
by Navid C. Constantinou; Petros J. Ioannou
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Highly stratified shear layers are rendered unstable even at high stratifications by Holmboe instabilities when the density stratification is concentrated in a small region of the shear layer. These instabilities may cause mixing in highly stratified environments. However these instabilities occur in limited bands in the parameter space. We perform Generalized Stability analysis of the two dimensional perturbation dynamics of an inviscid Boussinesq stratified shear layer and show that Holmboe...
Source: http://arxiv.org/abs/1011.0409v3
Arxiv.org
by Ahmad Sheykhi; Seyed Hossein Hendi
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A possible source of black hole entropy could be the entanglement of quantum fields in and out the horizon. The entanglement entropy of the ground state obeys the area law. However, a correction term proportional to a fractional power of area results when the field is in a superposition of ground and excited states. Inspired by the power-law corrections to entropy and adopting the viewpoint that gravity emerges as an entropic force, we derive modified Newton's law of gravitation as well as the...
Source: http://arxiv.org/abs/1011.0676v3
Arxiv.org
by Sungtae Cho; Takenori Furumoto; Tetsuo Hyodo; Daisuke Jido; Che Ming Ko; Su Houng Lee; Marina Nielsen; Akira Ohnishi; Takayasu Sekihara; Shigehiro Yasui; Koichi Yazaki
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Identifying hadronic molecular states and/or hadrons with multi-quark components either with or without exotic quantum numbers is a long standing challenge in hadronic physics. We suggest that studying the production of these hadrons in relativistic heavy ion collisions offer a promising resolution to this problem as yields of exotic hadrons are expected to be strongly affected by their structures. Using the coalescence model for hadron production, we find that compared to the case of a...
Source: http://arxiv.org/abs/1011.0852v2
Arxiv.org
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We construct finite-dimensional approximations of solution spaces of divergence form operators with $L^\infty$-coefficients. Our method does not rely on concepts of ergodicity or scale-separation, but on the property that the solution space of these operators is compactly embedded in $H^1$ if source terms are in the unit ball of $L^2$ instead of the unit ball of $H^{-1}$. Approximation spaces are generated by solving elliptic PDEs on localized sub-domains with source terms corresponding to...
Source: http://arxiv.org/abs/1011.0986v2
Arxiv.org
by Toshio Oshima; Nobukazu Shimeno
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We characterize the image of the Poisson transform on any distinguished boundary of a Riemannian symmetric space of the noncompact type by a system of differential equations. The system corresponds to a generator system of a two sided ideals of an universal enveloping algebra, which are explicitly given by analogues of minimal polynomials of matrices.
Source: http://arxiv.org/abs/1011.1314v2
Arxiv.org
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We study a fingerprinting game in which the number of colluders and the collusion channel are unknown. The encoder embeds fingerprints into a host sequence and provides the decoder with the capability to trace back pirated copies to the colluders. Fingerprinting capacity has recently been derived as the limit value of a sequence of maximin games with mutual information as their payoff functions. However, these games generally do not admit saddle-point solutions and are very hard to solve...
Source: http://arxiv.org/abs/1011.1261v2
Arxiv.org
by C. Mazza; C. Weibel
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We introduce the notion of a Schur-finite element in a $\lambda$-ring.
Source: http://arxiv.org/abs/1011.1444v2
Arxiv.org
by Bruno Iannazzo; Federico Poloni
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The worst situation in computing the minimal nonnegative solution of a nonsymmetric algebraic Riccati equation associated with an M-matrix occurs when the corresponding linearizing matrix has two very small eigenvalues, one with positive and one with negative real part. When both these eigenvalues are exactly zero, the problem is called critical or null recurrent. While in this case the problem is ill-conditioned and the convergence of the algorithms based on matrix iterations is slow, there...
Source: http://arxiv.org/abs/1011.1363v2
Arxiv.org
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The quantum theory of optical coherence is applied to the scrutiny of the statistical properties of the relic inflaton quanta. After adapting the description of the quantized scalar and tensor modes of the geometry to the analysis of intensity correlations, the normalized degrees of first-order and second-order coherence are computed in the concordance paradigm and are shown to encode faithfully the statistical properties of the initial quantum state. The strongly bunched curvature phonons are...
Source: http://arxiv.org/abs/1011.1673v2
Arxiv.org
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The weak magnetic field induced reduction of the low-temperature superfluid density in cuprate superconductors is studied based on the kinetic energy driven superconducting mechanism. The electromagnetic response kernel is evaluated by considering both couplings of the electron charge and electron magnetic momentum with a weak magnetic field and employed to calculate the superfluid density, then the main features of the weak magnetic field induced reduction of the low-temperature superfluid...
Source: http://arxiv.org/abs/1011.1546v2
Arxiv.org
by JLQCD collaboration; K. Takeda; S. Aoki; S. Hashimoto; T. Kaneko; J. Noaki; T. Onogi
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Strange quark content of the nucleon is calculated in dynamical lattice QCD employing the overlap fermion formulation. For this quantity, exact chiral symmetry guaranteed by the Ginsparg-Wilson relation is crucial to avoid large contamination due to a possible operator mixing with $\bar{u}u+\bar{d}d$. Gauge configurations are generated with two dynamical flavors on a 16^3 x 32 lattice at a lattice spacing a \simeq 0.12fm. We directly calculate the relevant three-point function on the lattice...
Source: http://arxiv.org/abs/1011.1964v2
Arxiv.org
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We establish Manin's conjecture for a quartic del Pezzo surface split over Q and having a singularity of type A_3 and containing exactly four lines. It is the first example of split singular quartic del Pezzo surface whose universal torsor is not a hypersurface for which Manin's conjecture is proved.
Source: http://arxiv.org/abs/1011.2470v3
Arxiv.org
by Peter Kuchment; Leonid Kunyansky
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We propose and test stable algorithms for the reconstruction of the internal conductivity of a biological object using acousto-electric measurements. Namely, the conventional impedance tomography scheme is supplemented by scanning the object with acoustic waves that slightly perturb the conductivity and cause the change in the electric potential measured on the boundary of the object. These perturbations of the potential are then used as the data for the reconstruction of the conductivity. The...
Source: http://arxiv.org/abs/1011.3059v3
Arxiv.org
by M. C. Babiuc; B. Szilagyi; J. Winicour; Y. Zlochower
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We develop and calibrate a characteristic waveform extraction tool whose major improvements and corrections of prior versions allow satisfaction of the accuracy standards required for advanced LIGO data analysis. The extraction tool uses a characteristic evolution code to propagate numerical data on an inner worldtube supplied by a 3+1 Cauchy evolution to obtain the gravitational waveform at null infinity. With the new extraction tool, high accuracy and convergence of the numerical error can be...
Source: http://arxiv.org/abs/1011.4223v3
Arxiv.org
by Vivek F. Farias; Srikanth Jagabathula; Devavrat Shah
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Choice models, which capture popular preferences over objects of interest, play a key role in making decisions whose eventual outcome is impacted by human choice behavior. In most scenarios, the choice model, which can effectively be viewed as a distribution over permutations, must be learned from observed data. The observed data, in turn, may frequently be viewed as (partial, noisy) information about marginals of this distribution over permutations. As such, the search for an appropriate...
Source: http://arxiv.org/abs/1011.4339v2
Arxiv.org
by J. Ricardo G. Mendonça; Mário J. de Oliveira
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We describe an approach to model biochemical reaction networks at the level of promotion-inhibition circuitry through a class of stochastic spin models that depart from the usual chemical kinetics setup and includes spatial and temporal density fluctuations in a most natural way. A particular but otherwise generally applicable choice for the microscopic transition rates of the models also makes them of independent interest. To illustrate the formalism, we investigate some stationary state...
Source: http://arxiv.org/abs/1011.4976v2
Arxiv.org
by Zhen-Hua Zhang; Xin-Heng Guo; Gang Lü
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We prove that in the limit $m_b, m_c\to\infty$ with $m_c/m_b$ fixed, factorization holds at order $\alpha_s$ for the decay $\Lambda_b^0\to\Lambda_c^+\pi^-$. This proof is done in the infinite-momentum frame in which the momenta of $\pi$, $\Lambda_c$, and $\Lambda_b$ go to infinity. Our result is renormalization scale and scheme independent at $\mathcal{O}(\alpha_s)$. This is the same as QCD factorization for $B \to D \pi$.
Source: http://arxiv.org/abs/1011.6522v2
Arxiv.org
by Peter Orbanz
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We characterize conjugate nonparametric Bayesian models as projective limits of conjugate, finite-dimensional Bayesian models. In particular, we identify a large class of nonparametric models representable as infinite-dimensional analogues of exponential family distributions and their canonical conjugate priors. This class contains most models studied in the literature, including Dirichlet processes and Gaussian process regression models. To derive these results, we introduce a representation...
Source: http://arxiv.org/abs/1012.0363v2
Arxiv.org
by David Bermudez; David J. Fernández C
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As it has been proven, the determination of general one-dimensional Schr\"odinger Hamiltonians having third-order differential ladder operators requires to solve the Painlev\'e IV equation. In this work, it will be shown that some specific subsets of the higher-order supersymmetric partners of the harmonic oscillator possess third-order differential ladder operators. This allows us to introduce a simple technique for generating solutions of the Painlev\'e IV equation. Finally, we classify...
Source: http://arxiv.org/abs/1012.0290v4
Arxiv.org
by Alexander F. Klinskikh; Anton V. Dolgikh; Peter A. Meleshenko; Sergey A. Sviridov
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The problem of electron scattering on the one-dimensional complexes is considered. We propose a novel theoretical approach to solution of the transport problem for a quantum graph. In the frame of the developed approach the solution of the transport problem is equivalent to the solution of a linear system of equations for the \emph{vertex amplitudes} $\mathbf{\Psi}$. All major properties, such as transmission and reflection amplitudes, wave function on the graph, probability current, are...
Source: http://arxiv.org/abs/1012.3634v2
Arxiv.org
by Alessandro Torrielli
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We review the study of Hopf algebras, classical and quantum R-matrices, infinite-dimensional Yangian symmetries and their representations in the context of integrability for the N=4 vs AdS5xS5 correspondence.
Source: http://arxiv.org/abs/1012.4005v5
Arxiv.org
by Takeshi Fukuyama; Hiroaki Sugiyama; Koji Tsumura
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The Zee model generates neutrino masses at the one-loop level by adding charged SU(2)_L-singlet and extra SU(2)_L-doublet scalars to the standard model of particle physics. As the origin of the nontrivial structure of the lepton flavor mixing, we introduce the softly broken A_4 symmetry to the Zee model. This model is compatible with the tribimaximal mixing which agrees well with neutrino oscillation measurements. Then, a sum rule m_1 e^{i alpha_12} + 2 m_2 + 3 m_3 e^{i alpha_32} = 0 is...
Source: http://arxiv.org/abs/1012.4886v3
Arxiv.org
by Christian Klein-Boesing; for the ALICE Collaboration
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Since the beginning of 2010 the LHC provides p+p collisions at the highest center of mass energies to date, allowing to study high $\pT$ particle production and jet properties in a new energy regime. For a clear interpretation and the quantification of the medium influence in heavy-ion collisions on high $\pT$ observables a detailed understanding of these elementary reactions is essential. We present first results on the observation of jet-like properties with the ALICE experiment and discuss...
Source: http://arxiv.org/abs/1101.0521v2
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In 1986 Lovasz, Spencer, and Vesztergombi proved a lower bound for the hereditary a discrepancy of a set system F in terms of determinants of square submatrices of the incidence matrix of F. As shown by an example of Hoffman, this bound can differ from herdisc(F) by a multiplicative factor of order almost log n, where n is the size of the ground set of F. We prove that it never differs by more than O((log n)3/2), assuming |F| bounded by a polynomial in n. We also prove that if such an F is the...
Source: http://arxiv.org/abs/1101.0767v2
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by Yukihiro Ota; Masahiko Machida; Tomio Koyama
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We present a dynamical theory for the phase differences along a stacked direction of intrinsic Josephson junctions (IJJ's) in layered multigap superconductors, motivated by the discovery of highly-anisotropic iron-based superconductors with thick perovskite-type blocking layers. The dynamical equations describing AC and DC intrinsic Josephson effects peculiar to multigap IJJ's are derived, and collective Leggett mode excitations in addition to the Josephson plasma established in single-gap...
Source: http://arxiv.org/abs/1101.0886v2
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We study the reactions e+e- --> e+e- eta (eta') in the single-tag mode and measure the gamma gamma* --> eta (eta') transition form factors in the momentum transfer range from 4 to 40 GeV^2. The analysis is based on 469 fb-1 of integrated luminosity collected at PEP-II with the BABAR detector at e+e- center-of-mass energies near 10.6 GeV.
Source: http://arxiv.org/abs/1101.1142v2
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by R. J. Foley; K. Andersson; G. Bazin; T. de Haan; J. Ruel; P. A. R. Ade; K. A. Aird; R. Armstrong; M. L. N. Ashby; M. Bautz; B. A. Benson; L. E. Bleem; M. Bonamente; M. Brodwin; J. E. Carlstrom; C. L. Chang; A. Clocchiatti; T. M. Crawford; A. T. Crites; S. Desai; M. A. Dobbs; J. P. Dudley; G. G. Fazio; W. R. Forman; G. Garmire; E. M. George; M. D. Gladders; A. H. Gonzalez; N. W. Halverson; F. W. High; G. P. Holder; W. L. Holzapfel; S. Hoover; J. D. Hrubes; C. Jones; M. Joy; R. Keisler; L. Knox;...
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Using the South Pole Telescope (SPT), we have discovered the most massive known galaxy cluster at z > 1, SPT-CL J2106-5844. In addition to producing a strong Sunyaev-Zel'dovich effect signal, this system is a luminous X-ray source and its numerous constituent galaxies display spatial and color clustering, all indicating the presence of a massive galaxy cluster. VLT and Magellan spectroscopy of 18 member galaxies shows that the cluster is at z = 1.132^+0.002_-0.003. Chandra observations...
Source: http://arxiv.org/abs/1101.1286v1
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The Turan bound is a famous result in graph theory, which relates the independence number of an undirected graph to its edge density. Also the Caro-Wei inequality, which gives a more refined bound in terms of the vertex degree sequence of a graph, might be regarded today as a classical result. We show how these statements can be generalized to directed graphs, thus yielding a bound on directed feedback vertex number in terms of vertex outdegrees and in terms of average outdegree, respectively.
Source: http://arxiv.org/abs/1101.1291v2
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by Andrew Das Arulsamy; Zlatko Kregar; Kristina Elersic; Martina Modic; Uma Shankar Subramani
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Hydrogen produced from the photocatalytic splitting of water is one of the reliable alternatives to replace the polluting fossil and the radioactive nuclear fuels. Here, we provide unequivocal evidence for the existence of blue- and red-shifting O$-$H covalent bonds within a single water molecule adsorbed on MgO surface as a result of asymmetric displacement polarizabilities. The adsorbed H-O-H on MgO gives rise to one weaker H-O bond, while the other O-H covalent bond from the same adsorbed...
Source: http://arxiv.org/abs/1101.1259v2
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by K. Kayabol; J. L. Sanz; D. Herranz; E. E. Kuruoglu; E. Salerno
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We propose a Bayesian approach to joint source separation and restoration for astrophysical diffuse sources. We constitute a prior statistical model for the source images by using their gradient maps. We assume a t-distribution for the gradient maps in different directions, because it is able to fit both smooth and sparse data. A Monte Carlo technique, called Langevin sampler, is used to estimate the source images and all the model parameters are estimated by using deterministic techniques.
Source: http://arxiv.org/abs/1101.1397v1
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by Paolo Sibani; Simon Christiansen
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In recent experiments by Richardson et al. ((2010), PLoS ONE 5(3): e9621. doi:10.1371/ journal.pone.0009621) ant motion out of the nest is shown to be a non-stationary process intriguingly similar to the dynamics encountered in \emph{physical aging} of glassy systems. Specifically, exit events can be described as a Poisson process in logarithmic time, or, for short, a log-Poisson process. Nouvellet et al.(J. Theor. Biol. 266, 573. (2010)) criticized these conclusions and performed new...
Source: http://arxiv.org/abs/1101.1461v2
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by Jean Fromentin; Luis Paris
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We describe a new algorithm which for each braid returns a quasi-geodesic sigma-definite word representative, defined as a braid word in which the generator sigma_i with maximal index i appears either only positively or only negatively.
Source: http://arxiv.org/abs/1101.1400v1
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by Sergey Fedoruk; Evgeny Ivanov; Jerzy Lukierski
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We apply the nonlinear realizations method for constructing new Galilean conformal mechanics models. Our starting point is the Galilean conformal algebra which is a non-relativistic contraction of its relativistic counterpart. We calculate Maurer-Cartan one-forms, examine various choices of the relevant coset spaces and consider the geometric inverse Higgs-type constraints which reduce the number of the independent coset parameters and, in some cases, provide dynamical equations. New Galilean...
Source: http://arxiv.org/abs/1101.1658v2
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Causes of the unsatisfactory condition of the gravitational-wave experiments are discussed and a new outlook at the detection of gravitational waves of astrophysical origin is proposed. It is shown that there are strong grounds for identifying the so-called giant pulses in the pulsar NP 0532 radiation with gravimagnetic shock waves (GMSW) excited in the neutron star magnetosphere by sporadic gravitational radiation of this pulsar.
Source: http://arxiv.org/abs/1101.1641v1
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by Denys Dutykh; Theodoros Katsaounis; Dimitrios Mitsotakis
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Finite volume schemes are commonly used to construct approximate solutions to conservation laws. In this study we extend the framework of the finite volume methods to dispersive water wave models, in particular to Boussinesq type systems. We focus mainly on the application of the method to bidirectional nonlinear, dispersive wave propagation in one space dimension. Special emphasis is given to important nonlinear phenomena such as solitary waves interactions.
Source: http://arxiv.org/abs/1101.1728v1
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The accurate determination of cluster total mass is crucial for their use as probes of cosmology. Recently, the Sunyaev--Zel'dovich effect (SZE) has been exploited in surveys to find galaxy clusters, but X-ray or lensing follow up observations, or empirically-determined scaling relations between SZE flux and total mass, have been required to estimate their masses. Here we demonstrate a new method of mass determination from SZE observations, applicable in the absence of X-ray or lensing data....
Source: http://arxiv.org/abs/1101.2176v4
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by Artem Badasyan; Shushanik A. Tonoyan; Yevgeni Sh. Mamasakhlisov; Achille Giacometti; Albert S. Benight; Vladimir F. Morozov
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The problem of the helix-coil transition of biopolymers in explicit solvents, like water, with the ability for hydrogen bonding with solvent is addressed analytically using a suitably modified version of the Generalized Model of Polypeptide Chains. Besides the regular helix-coil transition, an additional coil-helix or reentrant transition is also found at lower temperatures. The reentrant transition arises due to competition between polymer-polymer and polymer-water hydrogen bonds. The balance...
Source: http://arxiv.org/abs/1101.2861v2
It is shown that in the experiments dedicated for producing of polarized beams of antiprotons during their passage through a polarized gas target placed in a storage ring it is possible to measure not only spin-dependent total cross-sections of antiproton scattering by the proton (deuteron), but also the spin-dependent real part of the coherent zero-angle scattering amplitude in the process of production of a polarized beam of antiprotons.
Source: http://arxiv.org/abs/1101.3146v1
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The stability of the orbital motion of two long cylindrical magnets interacting exclusively with magnetic forces is described. To carry out analytical studies a model of magnetically interacting symmetric tops [1] is used. The model was previously developed within the quasi-stationary approach for an electromagnetic field based on the general expression of the energy of interacting magnetic bodies [2]. A special role in the investigation of the stability of orbital motions is played by the...
Source: http://arxiv.org/abs/1101.3237v1
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by Guanfeng Liang; Nitin Vaidya
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In this paper, we present an efficient deterministic algorithm for consensus in presence of Byzantine failures. Our algorithm achieves consensus on an $L$-bit value with communication complexity $O(nL + n^4 L^{0.5} + n^6)$ bits, in a network consisting of $n$ processors with up to $t$ Byzantine failures, such that $t
Source: http://arxiv.org/abs/1101.3520v1
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by Claire Amiot
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Cluster categories have been introduced by Buan, Marsh, Reineke, Reiten and Todorov in order to categorify Fomin-Zelevinsky cluster algebras. This survey motivates and outlines the construction of a generalization of cluster categories, and explains different applications of these new categories in representation theory.
Source: http://arxiv.org/abs/1101.3675v2
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by Gerard Ben Arous; Alan Hammond
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As a model of trapping by biased motion in random structure, we study the time taken for a biased random walk to return to the root of a subcritical Galton-Watson tree. We do so for trees in which these biases are randomly chosen, independently for distinct edges, according to a law that satisfies a logarithmic non-lattice condition. The mean return time of the walk is in essence given by the total conductance of the tree. We determine the asymptotic decay of this total conductance, finding it...
Source: http://arxiv.org/abs/1101.4041v1
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by Kimmo Kainulainen; Valerio Marra
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The halo model (HM) describes the inhomogeneous universe as a collection of halos. The full nonlinear power spectrum of the universe is well approximated by the HM, whose prediction can be easily computed without lengthy numerical simulations. This makes the HM a useful tool in cosmology. Here we explore the lensing properties of the HM by use of the stochastic gravitational lensing (sGL) method. We obtain for the case of point sources exact and simple integral expressions for the expected...
Source: http://arxiv.org/abs/1101.4143v3
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The anomaly of the top quark forward-backward asymmetry $A^t_{FB}$ observed at the Tevatron can be explained by the t-channel exchange of a neutral gauge boson (Z') which has sizable flavor changing coupling for top and up quarks. This gauge boson can also induce the top quark flavor-changing neutral-current (FCNC) decays and the like-sign top pair production at the LHC. In this work we focus on two models which predict such a Z', namely the left-right model and the U(1)_X model, to investigate...
Source: http://arxiv.org/abs/1101.4456v3
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by Roberto Bondesan; Jesper Lykke Jacobsen; Hubert Saleur
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The sigma models on projective superspaces CP^{N+M-1|N} with topological angle theta=pi mod 2pi flow to non-unitary, logarithmic conformal field theories in the low-energy limit. In this paper, we determine the exact spectrum of these theories for all open boundary conditions preserving the full global symmetry of the model, generalizing recent work on the particular case M=0 [C. Candu et al, JHEP02(2010)015]. In the sigma model setting, these boundary conditions are associated with complex...
Source: http://arxiv.org/abs/1101.4361v2
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by Thomas B. Bahder
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Numerous quantum mechanical schemes have been proposed that are intended to improve the sensitivity to rotation provided by the classical Sagnac effect in gyroscopes. A general metric is needed that can compare the performance of the new quantum systems with the classical systems. The fidelity (Shannon mutual information between the measurement and the rotation rate) is proposed as a metric that is capable of this comparison. A theoretical upper bound is derived for the fidelity of an ideal...
Source: http://arxiv.org/abs/1101.4634v1
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It is pointed out that the unmagnetized inhomogeneous plasmas can support a low frequency electromagnetic ion wave as a normal mode like Alfven wave of magnetized plasmas. But this is a coupled mode produced by the mixing of longitudinal and transverse components of perturbed electric field due to density inhomogeneity. The ion acoustic wave does not remain electrostatic in non-uniform plasmas. On the other hand, a low frequency electrostatic wave can also exist in the pure electron plasmas....
Source: http://arxiv.org/abs/1102.3497v1
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A two-component dark matter model is studied adopting the degenerate scenario in the R-parity conserving NMSSM. The gravitino LSP and the neutralino NLSP are extremely degenerate in mass, avoiding the BBN bounds and obtaining a high reheating temperature for thermal leptogenesis to work. In this model both gravitino (absolutely stable) and neutralino (quasi-stable) contribute to dark matter, and direct detection searches for neutralino are discussed. Points that survive all the constraints...
Source: http://arxiv.org/abs/1103.0140v1
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by Radu Ionicioiu; Daniel R. Terno
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Gedanken experiments are important conceptual tools in the quest to reconcile our classical intuition with quantum mechanics and nowadays are routinely performed in the laboratory. An important open question is the quantum behaviour of the controlling devices in such experiments. We propose a framework to analyse quantum-controlled experiments and illustrate the implications by discussing a quantum version of Wheeler's delayed-choice experiment. The introduction of a quantum-controlled device...
Source: http://arxiv.org/abs/1103.0117v2
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by Norio Konno; Iwao Sato
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We present an explicit formula for the characteristic polynomial of the transition matrix of the discrete-time quantum walk on a graph via the second weighted zeta function. As applications, we obtain new proofs for the results on spectra of the transition matrix and its positive support.
Source: http://arxiv.org/abs/1103.0079v2
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by Igor Travenec; Ladislav Samaj
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This article concerns the Weyl series of spectral functions associated with the Dirichlet Laplacian in a $d$-dimensional domain with a smooth boundary. In the case of the heat kernel, Berry and Howls predicted the asymptotic form of the Weyl series characterized by a set of parameters. Here, we concentrate on another spectral function, the (normalized) heat content. We show on several exactly solvable examples that, for even $d$, the same asymptotic formula is valid with different values of the...
Source: http://arxiv.org/abs/1103.0158v1
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by David G. Turner; Daniel J. Majaess; David J. Lane; J. Rosvick; Arne Henden; David Balam
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The Galactic calibration of the period-luminosity (PL) relation for classical Cepheids is examined using trigonometric, open cluster, and pulsation parallaxes, which help establish independent versions of the relationship. The calibration is important for the continued use of classical Cepheids in constraining cosmological models (by refining estimates for H_0), for defining zero-points for the SNe Ia and population II (Type II Cepheids/RR Lyrae variables) distance scales, for clarifying...
Source: http://arxiv.org/abs/1103.0275v1
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Time-resolved electron transport in nano-devices is described by means of a time-nonlocal quantum master equation for the reduced density operator. Our formulation allows for arbitrary time dependences of any device or contact parameter. The quantum master equation and the related expression for the electron current through the device are derived in fourth order of the coupling to the contacts. It is shown that a consistent sum up to infinite orders induces level broadening in the device. To...
Source: http://arxiv.org/abs/1103.0185v1
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We obtain global $W^{2,p}$ estimates for the Monge-Ampere equation under natural assumptions on the domain and boundary data.
Source: http://arxiv.org/abs/1103.0456v1
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by Duc-Phong Le; Chao-Liang Liu
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In 1986 Victor Miller described an algorithm for computing the Weil pairing in his unpublished manuscript. This algorithm has then become the core of all pairing-based cryptosystems. Many improvements of the algorithm have been presented. Most of them involve a choice of elliptic curves of a \emph{special} forms to exploit a possible twist during Tate pairing computation. Other improvements involve a reduction of the number of iterations in the Miller's algorithm. For the generic case, Blake,...
Source: http://arxiv.org/abs/1103.0337v1
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by Kazuyuki Fujii; Tatsuo Suzuki
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In this paper we treat the Jaynes-Cummings model with dissipation and give an approximate solution to the master equation for the density operator {\bf under the general setting} by making use of the Zassenhaus expansion.
Source: http://arxiv.org/abs/1103.0329v1
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I would like to consider the Beginning of space-time in this paper. First of all, we do consideration historical thought. A lot of philosophers have considered the relation between this real phenomenal world and the basic world in which the phenomenal world is grounded. We will glimpse thought historical details about such respect. Afterwards, we interpret the representation of space-time on Quantum theory and Relativistic theory. In this case, we will take recent results of time operator...
Source: http://arxiv.org/abs/1103.0806v1
We investigate which bipartite quantum states admit a symmetric extension and apply the results in the analysis of noise thresholds in quantum key distribution protocols with two-way postprocessing. We find that states that admit a symmetric extension can be decomposed into a convex combination of states that admit a_pure_ symmetric extension. For a state to have a pure symmetric extension, its nonzero eigenvalues must be equal to the nonzero eigenvalues of one of the subsystems. While this...
Source: http://arxiv.org/abs/1103.0766v1
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by Seán Dineen; Jorge Mujica
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We show that both $(\mathcal{H}(c_{0}),\tau_{\omega})$ and $(\mathcal{H}_{b}(c_{0}),\tau_{b})$ have a monomial Schauder basis.
Source: http://arxiv.org/abs/1103.0932v1
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by Tommaso Caneva; Tommaso Calarco; Simone Montangero
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In this work we describe in detail the "Chopped RAndom Basis" (CRAB) optimal control technique recently introduced to optimize t-DMRG simulations [arXiv:1003.3750]. Here we study the efficiency of this control technique in optimizing different quantum processes and we show that in the considered cases we obtain results equivalent to those obtained via different optimal control methods while using less resources. We propose the CRAB optimization as a general and versatile optimal...
Source: http://arxiv.org/abs/1103.0855v2