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Dec 30, 2011
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Dec 30, 2011
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Michele Castellana; Aurelien Decelle; Elia Zarinelli

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We study the probability distribution of the pseudo-critical temperature in a mean-field and in a short-range spin-glass model: the Sherrington-Kirkpatrick (SK) and the Edwards-Anderson (EA) model. In both cases, we put in evidence the underlying connection between the fluctuations of the pseudo-critical point and and the Extreme Value Statistics of random variables. For the SK model, both with Gaussian and binary couplings, the distribution of the pseudo-critical temperature is found to be the...

Source: http://arxiv.org/abs/1107.1795v2

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Dec 30, 2011
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Dec 30, 2011
by
Alexander Sviridenko; Oleg Shcherbina

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Five ordering algorithms for the nonserial dynamic programming algorithm for solving sparse discrete optimization problems are compared in this paper. The benchmarking reveals that the ordering of the variables has a significant impact on the run-time of these algorithms. In addition, it is shown that different orderings are most effective for different classes of problems. Finally, it is shown that, amongst the algorithms considered here, heuristics based on maximum cardinality search and...

Source: http://arxiv.org/abs/1107.1893v2

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Dec 30, 2011
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Dec 30, 2011
by
Wausu Kim

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Let $\mathscr{O}_K$ be a 2-adic discrete valuation ring with perfect residue field $k$. We classify $p$-divisible groups and $p$-power order finite flat group schemes over $\mathscr{O}_K$ in terms of certain Frobenius module over $\mathfrak{S}:=W(k)[[u]]$. We also show the compatibility with crystalline Dieudonn\'e theory and associated Galois representations. Our approach differs from Lau's generalization of display theory, and we additionally obtain the the compatibility with associated...

Source: http://arxiv.org/abs/1007.1904v3

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Dec 30, 2011
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Dec 30, 2011
by
A. Yu. Okulov

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We consider the cold bosonic ensemble trapped by a helical interference pattern in the optical \textit{loop} scheme. This rotating helical potential is produced by the two slightly detuned counter propagating Laguerre-Gaussian laser beams with counter directed orbital angular momenta $\pm \ell\hbar $. The detuning $\delta \omega$ may occur due to rotational Doppler effect. The superfluid hydrodynamics is analysed for the large number of trapped atoms in Thomas-Fermi approximation. For the...

Source: http://arxiv.org/abs/1005.4213v15

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Dec 30, 2011
12/11

Dec 30, 2011
by
Alastair Kay

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We analyze the effect of typical, unknown perturbations on the 2D toric code when acting as a quantum memory, incorporating the effects of error correction on read-out. By transforming the system into a 1D transverse Ising model undergoing an instantaneous quench, and making extensive use of Lieb-Robinson bounds, we prove that for a large class of perturbations, the survival time of stored information grows at least logarithmically with the system size. A uniform magnetic field saturates this...

Source: http://arxiv.org/abs/1107.3940v3

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Dec 29, 2011
12/11

Dec 29, 2011
by
CDF Collaboration

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We present the first measurement of polarization and CP-violating asymmetries in $B_s^0$ decays into two light vector mesons, $B_s^0 \to \phi\phi$, and an improved determination of its branching ratio using 295 decays reconstructed in a data sample corresponding to 2.9 fb^-1 of integrated luminosity collected by the CDF experiment at the Fermilab Tevatron collider. The fraction of longitudinal polarization is determined to be $\fL = 0.348 \pm 0.041 ({\rm stat}) \pm 0.021 ({\rm syst})$, and the...

Source: http://arxiv.org/abs/1107.4999v2

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Dec 29, 2011
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Dec 29, 2011
by
David Goss

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The calculation, by L.\ Euler, of the values at positive even integers of the Riemann zeta function, in terms of powers of $\pi$ and rational numbers, was a watershed event in the history of number theory and classical analysis. Since then many important analogs involving $L$-values and periods have been obtained. In analysis in finite characteristic, a version of Euler's result was given by L.\ Carlitz \cite{ca2} in the 1930's which involved the period of a rank 1 Drinfeld module (the Carlitz...

Source: http://arxiv.org/abs/1107.5031v3

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Dec 29, 2011
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Dec 29, 2011
by
F. Buisseret; G. Lacroix

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A PNJL model is built, in which the Polyakov-loop potential is explicitly Z$_{N_c}$-symmetric in order to mimic a Yang-Mills theory with gauge group SU($N_c$). The physically expected large-$N_c$ and large-$T$ behaviours of the thermodynamic observables computed from the Polyakov-loop potential are used to constrain its free parameters. The effective potential is eventually U(1)-symmetric when $N_c$ is infinite. Light quark flavours are added by using a Nambu-Jona-Lasinio (NJL) model coupled to...

Source: http://arxiv.org/abs/1107.4672v2

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Dec 29, 2011
12/11

Dec 29, 2011
by
Marc Hoffmann; Axel Munk; Johannes Schmidt-Hieber

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We study nonparametric estimation of the diffusion coefficient from discrete data, when the observations are blurred by additional noise. Such issues have been developed over the last 10 years in several application fields and in particular in high frequency financial data modelling, however mainly from a parametric and semiparametric point of view. This paper addresses the nonparametric estimation of the path of the (possibly stochastic) diffusion coefficient in a relatively general setting....

Source: http://arxiv.org/abs/1007.4622v2

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Dec 28, 2011
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Dec 28, 2011
by
Uwe R. Fischer; Bo Xiong

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We investigate the collapse and revival of first-order coherence in deep optical lattices when long-range interactions are turned on, and find that the first few revival peaks are strongly attenuated already for moderate values of the nearest-neighbor interaction coupling. It is shown that the conventionally employed Gutzwiller wavefunction, with only onsite-number dependence of the variational amplitudes, leads to incorrect predictions for the collapse and revival oscillations. We provide a...

Source: http://arxiv.org/abs/1107.3077v2

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Dec 28, 2011
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Dec 28, 2011
by
Hyeong-Kwan Ju; Seunghyun Seo

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We enumerate the number of 0/1-matrices avoiding 2x2 submatrices satisfying certain conditions. We also provide corresponding exponential generating functions.

Source: http://arxiv.org/abs/1107.1299v3

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Dec 28, 2011
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Dec 28, 2011
by
J. Bouttier; E. Guitter

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We present an unexpected connection between two map enumeration problems. The first one consists in counting planar maps with a boundary of prescribed length. The second one consists in counting planar maps with two points at a prescribed distance. We show that, in the general class of maps with controlled face degrees, the solution for both problems is actually encoded into the same quantity, respectively via its power series expansion and its continued fraction expansion. We then use known...

Source: http://arxiv.org/abs/1007.0419v3

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Dec 28, 2011
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Dec 28, 2011
by
M. Z. Sarikaya; H. Yaldiz

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In this paper, we establish some new inequalities of Hadamard's type for L-Lipschitzian mapping in two variables.

Source: http://arxiv.org/abs/1005.4138v2

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Dec 27, 2011
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Dec 27, 2011
by
P. Chowdhury; D. Home; A. S. Majumdar; S. V. Mousavi; M. R. Mozaffari; S. Sinha

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The weak equivalence principle of gravity is examined at the quantum level in two ways. First, the position detection probabilities of particles described by a non-Gaussian wave-packet projected upwards against gravity around the classical turning point and also around the point of initial projection are calculated. These probabilities exhibit mass-dependence at both these points, thereby reflecting the quantum violation of the weak equivalence principle. Secondly, the mean arrival time of...

Source: http://arxiv.org/abs/1107.5159v2

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Dec 26, 2011
12/11

Dec 26, 2011
by
D0 Collaboration

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We present a measurement of forward-backward asymmetry in top quark-antiquark production in proton-antiproton collisions in the final state containing a lepton and at least four jets. Using a dataset corresponding to an integrated luminosity of $5.4\,\mathrm {fb}^{-1}$, collected by the \DZ\ experiment at the Fermilab Tevatron Collider, we measure the \ttbar\ forward-backward asymmetry to be $(9.2 \pm 3.7)$% at the reconstruction level. When corrected for detector acceptance and resolution, the...

Source: http://arxiv.org/abs/1107.4995v2

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Dec 26, 2011
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Dec 26, 2011
by
Kazuto Takao

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For each integer k > 1, Johnson gave a 3-manifold with Heegaard splittings of genera 2k and 2k-1 such that any common stabilization of these two surfaces has genus at least 3k-1. We modify his argument to produce a 3-manifold with two Heegaard splitings of genus 2k such that any common stabilization of them has genus at least 3k.

Source: http://arxiv.org/abs/1005.1467v2

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Dec 25, 2011
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Dec 25, 2011
by
Luzi Bergamin; Pekka Alitalo; Sergei Tretyakov

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The concept of transformation optics is extended to nonlinear electrodynamics. It is shown that transformation optics favors implicit constitutive relations in terms of energy densities D.E and B.H rather than E^2 and H^2. The Kerr nonlinearity is studied in detail and the transformation optics based engineering of self-interaction effects is discussed. As a specific example we introduce transformation optics applied on a self-focusing field configuration.

Source: http://arxiv.org/abs/1107.0167v3

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Dec 24, 2011
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Dec 24, 2011
by
Evgeny Lakshtanov; Vera Roshchina

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The game of war is one of the most popular international children's card games. In the beginning of the game, the pack is split into two parts, then on each move the players reveal their top cards. The player having the highest card collects both and returns them to the bottom of his hand. The player left with no cards loses. Those who played this game in their childhood did not always have enough patience to wait until the end of the game. A player who has collected almost all the cards can...

Source: http://arxiv.org/abs/1007.1371v3

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42

Dec 24, 2011
12/11

Dec 24, 2011
by
J. B. Marston

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Planetary atmospheres, and models of them, are discussed from the viewpoint of condensed matter physics. Atmospheres are a form of condensed matter, and many interesting phenomena of condensed matter systems are realized by them. The essential physics of the general circulation is illustrated with idealized 2-layer and 1-layer models of the atmosphere. Equilibrium and non-equilibrium statistical mechanics are used to directly ascertain the statistics of these models.

Source: http://arxiv.org/abs/1107.5289v2

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Dec 24, 2011
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Dec 24, 2011
by
Luis P. Chimento; Martín G. Richarte

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We investigate a model of interacting dark matter and dark energy given by a modified holographic Ricci cutoff in a spatially flat Friedmann-Robertson-Walker (FRW) space-time. We consider a nonlinear interaction consisting of a significant rational function of the total energy density and its first derivative homogeneous of degree one and show that the effective one-fluid obeys the equation of state of a relaxed Chaplygin gas. So that, the universe is dominated by pressureless dark matter at...

Source: http://arxiv.org/abs/1107.4816v3

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Dec 24, 2011
12/11

Dec 24, 2011
by
Demian Levis; Leticia F. Cugliandolo

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We study the dynamics of 2d spin-ice following a quench from a fully disordered initial condition (equilibrium at infinite temperature) into its disordered, ferromagnetic and antiferromagnetic phases. We analyze the evolution of the density of topological defects and we show that these take finite density over very long periods of time in all kinds of quenches. We identify the leading mechanisms for the growth of domains in the ordered phases and we evaluate the (anisotropically) growing...

Source: http://arxiv.org/abs/1107.2528v2

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Dec 24, 2011
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Dec 24, 2011
by
M. Brodeur; T. Brunner; C. Champagne; S. Ettenauer; M. J. Smith; A. Lapierre; R. Ringle; V. L. Ryjkov; S. Bacca; P. Delheij; G. W. F. Drake; D. Lunney; A. Schwenk; J. Dilling

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The first direct mass-measurement of $^{6}$He has been performed with the TITAN Penning trap mass spectrometer at the ISAC facility. In addition, the mass of $^{8}$He was determined with improved precision over our previous measurement. The obtained masses are $m$($^{6}$He) = 6.018 885 883(57) u and $m$($^{8}$He) = 8.033 934 44(11) u. The $^{6}$He value shows a deviation from the literature of 4$\sigma$. With these new mass values and the previously measured atomic isotope shifts we obtain...

Source: http://arxiv.org/abs/1107.1684v4

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95

Dec 24, 2011
12/11

Dec 24, 2011
by
Amit Weinstein

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A sender wishes to broadcast a message of length $n$ over an alphabet to $r$ users, where each user $i$, $1 \leq i \leq r$ should be able to receive one of $m_i$ possible messages. The broadcast channel has noise for each of the users (possibly different noise for different users), who cannot distinguish between some pairs of letters. The vector $(m_1, m_2,...s, m_r)_{(n)}$ is said to be feasible if length $n$ encoding and decoding schemes exist enabling every user to decode his message. A rate...

Source: http://arxiv.org/abs/1005.1369v2

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186

Dec 24, 2011
12/11

Dec 24, 2011
by
David R. Law; Charles C. Steidel; Alice E. Shapley; Sarah R. Nagy; Naveen A. Reddy; Dawn K. Erb

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We present the results of a 42-orbit HST/WFC3 survey of the rest-frame optical morphologies of star forming galaxies with spectroscopic redshifts in the range z=1.5-3.6. The survey consists of 42 orbits of F160W imaging covering ~65 arcmin^2 distributed widely across the sky and reaching a depth of 27.9 AB for a 5 sigma detection within a 0.2 arcsec radius aperture. Focusing on an optically selected sample of 306 star forming galaxies with stellar masses in the range M* = 10^9 - 10^11 Msun, we...

Source: http://arxiv.org/abs/1107.3137v2

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123

Dec 23, 2011
12/11

Dec 23, 2011
by
D. B. Melrose; Rai Yuen

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Pulsar electrodynamics has been built up by taking ingredients from two models, the vacuum-dipole model, which ignores the magnetosphere but includes the inductive electric field due to the obliquely rotating magnetic dipole, and the corotating-magnetosphere model, which neglects the vacuum inductive electric field and assumes a corotating magnetosphere. We argue that the inductive field can be neglected only if it is screened by a current, ${\bi J}_{\rm sc}$, which we calculate for a rigidly...

Source: http://arxiv.org/abs/1107.0100v2

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Dec 23, 2011
12/11

Dec 23, 2011
by
Bao-Xi Sun; Hua-Xing Chen; E. Oset

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The rho-rho-N and rho-rho-Delta three-body systems have been studied within the framework of the fixed center approximation of Faddeev equation. The rho-rho interaction in isospin I=0, spin S=2 is strongly attractive, and so are the N-rho, Delta-rho interactions. This leads to bound states of both rho-rho-N and rho-rho-Delta. We find peaks of the modulus squared of the scattering matrix around 2227 MeV for rho-rho-N, and 2372 MeV for rho-rho-Delta. Yet, the strength of the peak for the...

Source: http://arxiv.org/abs/1107.0209v2

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6.0

Dec 23, 2011
12/11

Dec 23, 2011

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94

Dec 23, 2011
12/11

Dec 23, 2011
by
Matteo Casserini; Freddy Delbaen

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In this article, we study predictable projections of stochastic integrals with respect to the conformal Brownian motion, extending the connection between powers of the conformal Brownian motion and the corresponding Hermite polynomials. As a consequence of this result, we then investigate the relation between analytic functions and $L^p$-convergent series of Hermite polynomials. Finally, our results are applied to Widder's representation for a class of Brownian martingales, retrieving a...

Source: http://arxiv.org/abs/1107.5197v2

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37

Dec 22, 2011
12/11

Dec 22, 2011
by
John Atwell Moody

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Convergence of the Gauss resolution process for a complex singular foliation of dimension r is shown to be equivalent to finite type of a graded sheaf which is built using base (r+2) expansions of integers. As applications it is calculated which foliations coming from split semisimple representations of commutative Lie algebras can be resolved torically with respect to an eigenspace decomposition and it is shown that Gaussian resolutions stabilize for irreducible normal projective varieties...

Source: http://arxiv.org/abs/math/0406175v9

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37

Dec 22, 2011
12/11

Dec 22, 2011
by
Ning Ning Chung; Lock Yue Chew; Choy Heng Lai

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The extreme eigenvalues of adjacency matrices are important indicators on the influences of topological structures to collective dynamical behavior of complex networks. Recent findings on the ensemble averageability of the extreme eigenvalue further authenticate its sensibility in the study of network dynamics. Here we determine the ensemble average of the extreme eigenvalue and characterize the deviation across the ensemble through the discrete form of random scale-free network. Remarkably,...

Source: http://arxiv.org/abs/1107.2473v3

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136

Dec 22, 2011
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Dec 22, 2011
by
Xian Gao; Daniele A. Steer

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We set up cosmological perturbation theory and study the cosmological implications of the so-called ``generalized Galileon'' developed in \cite{Deffayet:2011gz,horndeski}. This is the most general scalar field theory whose Lagrangian contains derivatives up to second order while keeping second order equations of motion, and contains as sub-cases $k$-inflation, $G$-inflation and many other models. We calculate the power spectrum of the primordial curvature perturbation, finding a modification of...

Source: http://arxiv.org/abs/1107.2642v3

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Dec 22, 2011
12/11

Dec 22, 2011
by
Michael Falk; Martin Hofmann

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We investigate the sojourn time above a high threshold of a continuous stochastic process Y on [0,1]. It turns out that the limit, as the threshold increases, of the expected sojourn time given that it is positive, exists if the copula process corresponding to Y is in the functional domain of attraction of of an extreme value process. This limit coincides with the limit of the fragility index corresponding to finite (n-)dimensional distributions of Y as n and the threshold increase. If the...

Source: http://arxiv.org/abs/1107.5696v2

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123

Dec 22, 2011
12/11

Dec 22, 2011
by
Enrico Costa; Filippo Frontera

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In this paper we review the story of the BeppoSAX discovery of the Gamma Ray Burst afterglow and their cosmological distance, starting from their first detection with Vela satellites and from the efforts done before BeppoSAX. We also discuss the consequences of the BeppoSAX discovery, the issues left open by BeppoSAX, the progress done up to now and its perspectives.

Source: http://arxiv.org/abs/1107.1661v2

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Dec 22, 2011
12/11

Dec 22, 2011
by
Daniel Boer; Leonard Gamberg; Bernhard Musch; Alexei Prokudin

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The concept of weighted asymmetries is revisited for semi-inclusive deep inelastic scattering. We consider the cross section in Fourier space, conjugate to the outgoing hadron's transverse momentum, where convolutions of transverse momentum dependent parton distribution functions and fragmentation functions become simple products. Individual asymmetric terms in the cross section can be projected out by means of a generalized set of weights involving Bessel functions. Advantages of employing...

Source: http://arxiv.org/abs/1107.5294v2

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70

Dec 22, 2011
12/11

Dec 22, 2011
by
Ron Donagi; Tony Pantev

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We show that the Hitchin integrable system for a simple complex Lie group $G$ is dual to the Hitchin system for the Langlands dual group $\lan{G}$. In particular, the general fiber of the connected component $\Higgs_0$ of the Hitchin system for $G$ is an abelian variety which is dual to the corresponding fiber of the connected component of the Hitchin system for $\lan{G}$. The non-neutral connected components $\Higgs_{\alpha}$ form torsors over $\Higgs_0$. We show that their duals are gerbes...

Source: http://arxiv.org/abs/math/0604617v3

One in a series of podcasts from Shrink Rap Radio, All the psychology you need to know and just enough to make you dangerous"

Topics: psychology, psychotherapy, counseling, counselor, therapist, psychotherapist, intuition, dreams,...

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125

Dec 22, 2011
12/11

Dec 22, 2011
by
Half Moon

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Half Moon 12/22/11 - Thursday Martin's Downtown Bar & Grill, Roanoke, VA 01. Tuning/Intro > 02. Celebrate 03. Air Tight > Womb > 04. Susie D 05. Nov 12th > 06. The News > 07. White Christmas > 08. The News > 09. Room 2 10. Bright Green > 11. Neil Source: CA-14s(Omnis, ~XY90) > STC-9000 > DR-05(LineIn) > WAV(24bit/48khz) > Audacity1.3.11b(amplified to -.01db, dithered, resampled) > WAV(16bit/44.1khz) > CD Wave Editor(tracked) > FLAC8(TLH)...

Source: CA-14s(Omnis, ~XY90) > STC-9000 > DR-05(LineIn) > WAV(24bit/48khz)

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85

Dec 22, 2011
12/11

Dec 22, 2011
by
Charalampos Anastasiou; Stephan Buehler; Franz Herzog; Achilleas Lazopoulos

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We present a new program (iHixs) which computes the inclusive Higgs boson cross-section at hadron colliders. It incorporates QCD corrections through NNLO, real and virtual electroweak corrections, mixed QCD-electroweak corrections, quark-mass effects through NLO in QCD, and finite width effects for the Higgs boson and heavy quarks. iHixs can be used to obtain the most precise cross-section values in fixed order perturbation theory in the Standard Model. In addition, it allows for a consistent...

Source: http://arxiv.org/abs/1107.0683v3

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260

Dec 22, 2011
12/11

Dec 22, 2011
by
Wei Xu

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For large scale learning problems, it is desirable if we can obtain the optimal model parameters by going through the data in only one pass. Polyak and Juditsky (1992) showed that asymptotically the test performance of the simple average of the parameters obtained by stochastic gradient descent (SGD) is as good as that of the parameters which minimize the empirical cost. However, to our knowledge, despite its optimal asymptotic convergence rate, averaged SGD (ASGD) received little attention in...

Source: http://arxiv.org/abs/1107.2490v2

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99

Dec 22, 2011
12/11

Dec 22, 2011
by
Tony Gherghetta; Alex Pomarol

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We show that when supersymmetry is broken at the TeV scale by strong dynamics, the Higgs sector of the MSSM can be drastically modified. This arises from possible sizeable mixings of the Higgs with the resonances of the strong sector. In particular the mass of the lightest Higgs boson can be significantly above the MSSM bound (~130 GeV). Furthermore only one Higgs doublet is strictly necessary, because the Yukawa couplings can have a very different structure compared to the MSSM. Using the...

Source: http://arxiv.org/abs/1107.4697v2

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52

Dec 22, 2011
12/11

Dec 22, 2011
by
Michele Frigerio; Thomas Hambye; Eduard Masso

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Pseudo Nambu-Goldstone bosons (pNGBs) are naturally light spin-zero particles, which can be interesting dark matter (DM) candidates. We study the phenomenology of a pNGB theta associated with an approximate symmetry of the neutrino seesaw sector. A small coupling of theta to the Higgs boson is induced radiatively by the neutrino Yukawa couplings. By virtue of this Higgs portal interaction (i) the pNGB acquires a mass m_theta proportional to the electroweak scale, and (ii) the observed DM relic...

Source: http://arxiv.org/abs/1107.4564v2

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96

Dec 21, 2011
12/11

Dec 21, 2011
by
Nicolas Boulanger; E. D. Skvortsov

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Nonabelian Fradkin-Vasiliev cubic interactions for dual-graviton-like gauge fields with gravity and themselves are constructed in anti-de Sitter spacetime. The Young diagrams of gauge potentials have shapes of 'tall-hooks', i.e. two columns the second of height one. The underlying nonabelian algebra is a Clifford algebra with the anti-de Sitter signature. We also discuss the universal enveloping realization of higher-spin algebras, showing that there is a one-parameter family of algebras...

Source: http://arxiv.org/abs/1107.5028v3

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33

Dec 21, 2011
12/11

Dec 21, 2011
by
A. Seibert; S. Denisov; A. V. Ponomarev; P. Hänggi

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The Arnold diffusion constitutes a dynamical phenomenon which may occur in the phase space of a non-integrable Hamiltonian system whenever the number of the system degrees of freedom is $M \geq 3$. The diffusion is mediated by a web-like structure of resonance channels, which penetrates the phase space and allows the system to explore the whole energy shell. The Arnold diffusion is a slow process; consequently the mapping of the web presents a very time-consuming task. We demonstrate that the...

Source: http://arxiv.org/abs/1107.4107v2

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160

Dec 21, 2011
12/11

Dec 21, 2011
by
Anindya De

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This is a paper about private data analysis, in which a trusted curator holding a confidential database responds to real vector-valued queries. A common approach to ensuring privacy for the database elements is to add appropriately generated random noise to the answers, releasing only these {\em noisy} responses. In this paper, we investigate various lower bounds on the noise required to maintain different kind of privacy guarantees.

Source: http://arxiv.org/abs/1107.2183v2

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Dec 21, 2011
12/11

Dec 21, 2011
by
A. Chiuri; V. Rosati; G. Vallone; S. Pádua; H. Imai; S. Giacomini; C. Macchiavello; P. Mataloni

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We present the experimental realization of the optimal estimation protocol for a Pauli noisy channel. The method is based on the generation of 2-qubit Bell states and the introduction of quantum noise in a controlled way on one of the state subsystems. The efficiency of the optimal estimation, achieved by a Bell measurement, is shown to outperform quantum process tomography.

Source: http://arxiv.org/abs/1107.0888v2

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Dec 21, 2011
12/11

Dec 21, 2011
by
Akira R. Kinjo; Haruki Nakamura

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Most biological processes are described as a series of interactions between proteins and other molecules, and interactions are in turn described in terms of atomic structures. To annotate protein functions as sets of interaction states at atomic resolution, and thereby to better understand the relation between protein interactions and biological functions, we conducted exhaustive all-against-all atomic structure comparisons of all known binding sites for ligands including small molecules,...

Source: http://arxiv.org/abs/1107.3278v2

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Dec 21, 2011
12/11

Dec 21, 2011
by
D. T. O'Dea; C. N. Clark; C. R. Contaldi; C. J. MacTavish

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The upcoming generation of cosmic microwave background (CMB) experiments face a major challenge in detecting the weak cosmic B-mode signature predicted as a product of primordial gravitational waves. To achieve the required sensitivity these experiments must have impressive control of systematic effects and detailed understanding of the foreground emission that will influence the signal. In this paper, we present templates of the intensity and polarisation of emission from one of the main...

Source: http://arxiv.org/abs/1107.4612v2

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52

Dec 21, 2011
12/11

Dec 21, 2011
by
Fan Ding; Hansjörg Geiges

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We describe a necessary and sufficient condition for a principal circle bundle over an even-dimensional manifold to carry an invariant contact structure. As a corollary it is shown that all circle bundles over a given base manifold carry an invariant contact structure, only provided the trivial bundle does. In particular, all circle bundles over 4-manifolds admit invariant contact structures. We also discuss the Bourgeois construction of contact structures on odd-dimensional tori in this...

Source: http://arxiv.org/abs/1107.4948v2

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77

Dec 21, 2011
12/11

Dec 21, 2011
by
A. Stabile; G. Scelza

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We investigate the radial behavior of galactic rotation curves by a Fourth Order Gravity adding also the Dark Matter component. The Fourth Order Gravity is a Lagrangian containing the Ricci scalar, the Ricci and Riemann tensor, but the rotation curves are depending only on two free parameters. A systematic analysis of rotation curves, in the Newtonian Limit of theory, induced by all galactic sub-structures of ordinary matter is shown. This analysis is presented for Fourth Order Gravity with and...

Source: http://arxiv.org/abs/1107.5351v2

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99

Dec 20, 2011
12/11

Dec 20, 2011
by
Remigiusz Augusiak; Gniewomir Sarbicki; Maciej Lewenstein

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One of the unsolved problems in the characterization of the optimal entanglement witnesses is the existence of optimal witnesses acting on bipartite Hilbert spaces H_{m,n}=C^m\otimes C^n such that the product vectors obeying =0 do not span H_{m,n}. So far, the only known examples of such witnesses were found among indecomposable witnesses, one of them being the witness corresponding to the Choi map. However, it remains an open question whether decomposable witnesses exist without the property...

Source: http://arxiv.org/abs/1107.0505v3

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57

Dec 20, 2011
12/11

Dec 20, 2011
by
E. M. Bittar; C. Adriano; T. M. Garitezi; P. F. S. Rosa; L. Mendonça-Ferreira; F. Garcia; G. de M. Azevedo; P. G. Pagliuso; E. Granado

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The Fe K X-ray absorption near edge structure (XANES) of BaFe2-xCoxAs2 superconductors was investigated. No appreciable alteration in shape or energy position of this edge was observed with Co substitution. This result provides experimental support to previous ab initio calculations in which the extra Co electron is concentrated at the substitute site and do not change the electronic occupation of the Fe ions. Superconductivity may emerge due to bonding modifications induced by the substitute...

Source: http://arxiv.org/abs/1107.0962v3

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42

Dec 20, 2011
12/11

Dec 20, 2011
by
David W. Lyons; Scott N. Walck

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We classify, up to local unitary equivalence, local unitary stabilizer Lie algebras for symmetric mixed states into six classes. These include the stabilizer types of the Werner states, the GHZ state and its generalizations, and Dicke states. For all but the zero algebra, we classify entanglement types (local unitary equivalence classes) of symmetric mixed states that have those stabilizers. We make use of the identification of symmetric density matrices with polynomials in three variables with...

Source: http://arxiv.org/abs/1107.1372v2

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206

Dec 20, 2011
12/11

Dec 20, 2011
by
Stefan Kebekus

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This survey discusses hyperbolicity properties of moduli stacks and generalisations of the Shafarevich Hyperbolicity Conjecture to higher dimensions. It concentrates on methods and results that relate moduli theory with recent progress in higher dimensional birational geometry.

Source: http://arxiv.org/abs/1107.4239v2

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103

Dec 20, 2011
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Dec 20, 2011
by
Amit Ghosh; Alejandro Perez

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We present a statistical mechanical calculation of the thermodynamical properties of (non rotating) isolated horizons. The introduction of Planck scale allows for the definition of an universal horizon temperature (independent of the mass of the black hole) and a well-defined notion of energy (as measured by suitable local observers) proportional to the horizon area in Planck units. The microcanonical and canonical ensembles associated with the system are introduced. Black hole entropy and...

Source: http://arxiv.org/abs/1107.1320v3

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64

Dec 20, 2011
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Dec 20, 2011
by
Marija Dimitrijevic; Larisa Jonke

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Kappa-Minkowski space-time is an example of noncommutative space-time with potentially interesting phenomenological consequences. However, the construction of field theories on this space, although operationally well-defined, is plagued with ambiguities. A part of ambiguities can be resolved by clarifying the geometrical picture of gauge transformations on the kappa-Minkowski space-time. To this end we use the twist approach to construct the noncommutative U(1) gauge theory coupled to fermions....

Source: http://arxiv.org/abs/1107.3475v2

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Dec 20, 2011
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Dec 20, 2011
by
S. Meuren; A. Di Piazza

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The quantum state of an electron in a strong laser field is altered if the interaction of the electron with its own electromagnetic field is taken into account. Starting from the Schwinger-Dirac equation, we determine the states of an electron in a plane-wave field with inclusion, at leading order, of its electromagnetic self-interaction. On the one hand, the electron states show a pure "quantum" contribution to the electron quasi-momentum, conceptually different from the conventional...

Source: http://arxiv.org/abs/1107.4531v2

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53

Dec 20, 2011
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Dec 20, 2011
by
Markus J. Aschwanden

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{\sl Ground Level Enhancement (GLE)} events represent the largest class of {\sl solar energetic particle (SEP)} events that require acceleration processes to produce $\gapprox 1$ GeV ions in order to produce showers of secondary particles in the Earth's atmosphere with sufficient intensity to be detected by ground-level neutron monitors, above the background of cosmics rays. Although the association of GLE events with both solar flares and coronal mass ejections (CMEs) is undisputed, the...

Source: http://arxiv.org/abs/1005.0029v5

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102

Dec 19, 2011
12/11

Dec 19, 2011
by
Ilja Dorsner; Jure Drobnak; Svjetlana Fajfer; Jernej F. Kamenik; Nejc Kosnik

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A colored weak singlet scalar state with hypercharge 4/3 is one of the possible candidates for the explanation of the unexpectedly large forward-backward asymmetry in t tbar production as measured by the CDF and D0 experiments. We investigate the role of this state in a plethora of flavor changing neutral current processes and precision observables of down-quarks and charged leptons. Our analysis includes tree- and loop-level mediated observables in the K and B systems, the charged lepton...

Source: http://arxiv.org/abs/1107.5393v3

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47

Dec 19, 2011
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Dec 19, 2011
by
N. Lo Gullo; Th. Busch; G. M. Palma; M. Paternostro

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We propose a scheme to probe quantum coherence in the state of a nano-cantilever based on its magnetic coupling (mediated by a magnetic tip) with a spinor Bose Einstein condensate (BEC). By mapping the BEC into a rotor, its coupling with the cantilever results in a gyroscopic motion whose properties depend on the state of the cantilever: the dynamics of one of the components of the rotor angular momentum turns out to be strictly related to the presence of quantum coherence in the state of the...

Source: http://arxiv.org/abs/1107.0750v2

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Dec 19, 2011
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Dec 19, 2011
by
Marcelo Ponce; Joshua A. Faber; James C. Lombardi Jr

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Numerical calculations of merging black hole binaries indicate that asymmetric emission of gravitational radiation can kick the merged black hole at up to thousands of km/s, and a number of systems have been observed recently whose properties are consistent with an active galactic nucleus containing a supermassive black hole moving with substantial velocity with respect to its broader accretion disk. We study here the effect of an impulsive kick delivered to a black hole on the dynamical...

Source: http://arxiv.org/abs/1107.1711v2

Original Pinettes Brass Band - the first and only all female brass band - performing VIC's 'Wobble Baby' at the Maison on Frenchmen Street Source: https://www.youtube.com/watch?v=VuY4_nd5pt0 Uploader: BigRedCotton Upload date: 20111219

Topics: Youtube, video, Music, Original Pinettes Brass Band, New Orleans, Frenchmen Street, V.I.C., Wobble...

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90

Dec 19, 2011
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Dec 19, 2011
by
Pedro J. Catuogno; Fabiano B. da Silva; Paulo Ruffino

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We show that given a $G$-structure $P$ on a differentiable manifold $M$, if the group $G(M)$ of automorphisms of $P$ is big enough, then there exists the quotient of an stochastic flows $phi_t$ by $G(M)$, in the sense that $\phi_t = \xi_t \circ \rho_t$ where $\xi_t \in G(M)$, the remainder $\rho_t$ has derivative which is vertical but transversal to the fibre of $P$. This geometrical context generalizes previous results where $M$ is a Riemannian manifold and $\phi_t$ is decomposed with an...

Source: http://arxiv.org/abs/1007.1257v3

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99

Dec 19, 2011
12/11

Dec 19, 2011
by
Radouane Gannouji; M. Sami

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We derive field equations of Gauss-Bonnet gravity in 4 dimensions after dimensional reduction of the action and demonstrate that in this scenario Vainshtein mechanism operates in the flat spherically symmetric background. We show that inside this Vainshtein sphere the fifth force is negligibly small compared to the gravitational force. We also investigate stability of the spherically symmetric solution, clarify the vocabulary used in the literature about the hyperbolicity of the equation and...

Source: http://arxiv.org/abs/1107.1892v2

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45

Dec 19, 2011
12/11

Dec 19, 2011
by
Vyacheslav I. Dokuchaev; Yury N. Eroshenko

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We calculate analytically a back reaction of the stationary spherical accretion flow near the event horizon and near the inner Cauchy horizon of the charged black hole. It is shown that corresponding back-reaction corrections to the black hole metric depend only on the fluid accretion rate and diverge in the case of an extremely charged black hole. In result, the test fluid approximation for stationary accretion is violated for extreme black holes. This behavior of the accreting black hole is...

Source: http://arxiv.org/abs/1107.3322v2

Original Pinettes Brass Band - the first and only all female brass band - performing Rebirth Melody at the Maison on Frenchmen Street Source: https://www.youtube.com/watch?v=864wa4f78T0 Uploader: BigRedCotton Upload date: 20111219

Topics: Youtube, video, Music, Original Pinettes Brass Band, New Orleans, Frenchmen Street, debcotton,...

The Original Pinettes Brass Band - the first and only all female brass band - performing their original 'Get A Life'. Source: https://www.youtube.com/watch?v=WDmEvEF9IKc Uploader: BigRedCotton Upload date: 20111219

Topics: Youtube, video, Music, Pinettes Brass Band, New Orleans, Frenchmen Street, Jazz henry, Christie...

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61

Dec 19, 2011
12/11

Dec 19, 2011
by
E. Bossy; R. Carminati

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Radiation by elementary sources is a basic problem in wave physics. We show that the time-domain energy flux radiated from electromagnetic and acoustic subwalength sources exhibits remarkable features. In particular, a subtle trade-off between source emission and absorption underlies the mechanism of radiation. This behavior should be observed for any kind of classical waves, thus having broad potential implications. We discuss the implication for subwavelength focusing by time reversal with...

Source: http://arxiv.org/abs/1107.4237v5

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116

Dec 19, 2011
12/11

Dec 19, 2011
by
Carlo Marinelli; Stefano d'Addona; Svetlozar T. Rachev

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For purposes of Value-at-Risk estimation, we consider several multivariate families of heavy-tailed distributions, which can be seen as multidimensional versions of Paretian stable and Student's t distributions allowing different marginals to have different tail thickness. After a discussion of relevant estimation and simulation issues, we conduct a backtesting study on a set of portfolios containing derivative instruments, using historical US stock price data.

Source: http://arxiv.org/abs/1005.2862v3

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82

Dec 19, 2011
12/11

Dec 19, 2011
by
Takehito Yokoyama

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We investigate transverse Josephson current in superconductor/normal metal/superconductor junctions where the normal metal has Rashba type spin-orbit coupling. It is shown that trans- verse current arises from the spin-orbit coupling in the normal metal. This effect is specific to superconducting current and the transverse current vanishes in the normal state. In addition, this transverse Josephson effect is purely stationary and applied magnetic field is unnecessary to realize this effect, in...

Source: http://arxiv.org/abs/1107.4202v3

Original Pinettes Brass Band - the first and only all female brass band - performing 'I'm Missing You' by Lebrado Source: https://www.youtube.com/watch?v=S4FrasHbpr4 Uploader: BigRedCotton Upload date: 20111219

Topics: Youtube, video, Music, Original Pinettes Brass Band, New Orleans, Frenchmen Street, debcotton,...

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101

Dec 19, 2011
12/11

Dec 19, 2011
by
Paul Fulda; Keiko Kokeyama; Simon Chelkowski; Andreas Freise

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The compatibility of higher-order Laguerre-Gauss (LG) modes with interferometric technologies commonly used in gravitational wave detectors is investigated. In this paper we present the first experimental results concerning the performance of the LG33 mode in optical resonators. We show that the Pound-Drever-Hall error signal for a LG33 mode in a linear optical resonator is identical to that of the more commonly used LG00 mode, and demonstrate the feedback control of the resonator with a LG33...

Source: http://arxiv.org/abs/1005.2990v3

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154

Dec 18, 2011
12/11

Dec 18, 2011
by
Wai Ling Yee

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This paper provides a unifying and simplifying approach to Bruhat order in which the usual Bruhat order, parabolic Bruhat order, and Bruhat order for symmetric pairs are shown to have combinatorially analogous and relatively simple descriptions. Such analogies are valuable as they permit the study of PGB and KGB by reducing to BGB rather than by introducing additional machinery. A concise definition for reduced expressions and a simple proof of the exchange condition for PGB are provided as...

Source: http://arxiv.org/abs/1107.0518v3

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89

Dec 18, 2011
12/11

Dec 18, 2011
by
Mohammed Larbi Labbi

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This is a paper based on a talk given at the conference on Conformal Geometry which held at Roscoff in France in the 2008 summer. We study some aspects of the equation arising from the problem of the existence on a given closed Riemannian manifold of dimension at leat 4, of a conformal metric with constant $h_4$ curvature. We establish a simple formula relating the second Gauss-Bonnet curvature $h_4$ to the $\sigma_2$ curvature and we study some positivity properties of these two quadratic...

Source: http://arxiv.org/abs/0807.2058v2

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73

Dec 18, 2011
12/11

Dec 18, 2011
by
Vijayaraghavan Thirumalai; Pascal Frossard

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This paper addresses the problem of correlation estimation in sets of compressed images. We consider a framework where images are represented under the form of linear measurements due to low complexity sensing or security requirements. We assume that the images are correlated through the displacement of visual objects due to motion or viewpoint change and the correlation is effectively represented by optical flow or motion field models. The correlation is estimated in the compressed domain by...

Source: http://arxiv.org/abs/1107.4667v2

wait until spring, bandini

Topics: Occupy, Montreal, ows, 99&

Source: http://www.flickr.com/photos/ricardoaraujoara/6535132493/

17 December 2011

Topics: occupy, wall, street, ows, new, york, city

Source: http://www.flickr.com/photos/smallhaystack/6534398033/

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41

Dec 17, 2011
12/11

Dec 17, 2011
by
A. Zitrin; P. Rosati; M. Nonino; C. Grillo; M. Postman; D. Coe; S. Seitz; T. Eichner; T. Broadhurst; S. Jouvel; I. Balestra; A. Mercurio; M. Scodeggio; N. Benítez; L. Bradley; H. Ford; O. Host; Y. Jimenez-Teja; A. Koekemoer; W. Zheng; M. Bartelmann; R. Bouwens; O. Czoske; M. Donahue; O. Graur; G. Graves; L. Infante; S. Jha; D. Kelson; O. Lahav; R. Lazkoz; D. Lemze; M. Lombardi; D. Maoz; C. McCully; E. Medezinski; P. Melchior; M. Meneghetti; J. Merten; A. Molino; L. A. Moustakas; S. Ogaz; B....

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We present a strong-lensing analysis of the galaxy cluster MACS J1206.2-0847 ($z$=0.44) using UV, Optical, and IR, HST/ACS/WFC3 data taken as part of the CLASH multi-cycle treasury program, with VLT/VIMOS spectroscopy for some of the multiply-lensed arcs. The CLASH observations, combined with our mass-model, allow us to identify 47 new multiply-lensed images of 12 distant sources. These images, along with the previously known arc, span the redshift range $1\la z\la5.5$, and thus enable us to...

Source: http://arxiv.org/abs/1107.2649v3

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138

Dec 17, 2011
12/11

Dec 17, 2011
by
Nathanael L. Ackerman; Cameron E. Freer; Daniel M. Roy

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As inductive inference and machine learning methods in computer science see continued success, researchers are aiming to describe even more complex probabilistic models and inference algorithms. What are the limits of mechanizing probabilistic inference? We investigate the computability of conditional probability, a fundamental notion in probability theory and a cornerstone of Bayesian statistics, and show that there are computable joint distributions with noncomputable conditional...

Source: http://arxiv.org/abs/1005.3014v2

17 December 2011

Topics: occupy, wall, street, ows, new, york, city

Source: http://www.flickr.com/photos/smallhaystack/6534397223/

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51

Dec 17, 2011
12/11

Dec 17, 2011
by
Frank Loray; Jorge Vitorio Pereira; Frederic Touzet

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This paper is devoted to describe the structure of singular codimension one foliations with numerically trivial canonical bundle on projective manifolds. To achieve this goal we study the reduction modulo $p$ of foliations, establish a criterium for uniruledness of projective manifolds, and investigate the deformation of free morphisms along foliations. This paper also contains new information about the structure of codimension one foliations on $\P^n$ of degree smaller than or equal to $2n-3$.

Source: http://arxiv.org/abs/1107.1538v3

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90

Dec 17, 2011
12/11

Dec 17, 2011
by
R. Fiore; V. R. Zoller

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We discuss heavy quark contributions to the neutrino-nucleon total cross section at very high energies, well above the real top production threshold. The top-bottom weak current is found to generate strong left-right asymmetry of neutrino-nucleon interactions. We separate contributions of different helicity states and make use of the $\bkappa$-factorization to derive simple and practically useful formulas for the left-handed ($F_L$) and right-handed ($F_R$) components of the conventional...

Source: http://arxiv.org/abs/1107.4456v2

17 December 2011

Topics: occupy, wall, street, ows, new, york, city

Source: http://www.flickr.com/photos/smallhaystack/6534392783/

17 December 2011

Topics: occupy, wall, street, ows, new, york, city

Source: http://www.flickr.com/photos/smallhaystack/6534394011/

17 December 2011

Topics: occupy, wall, street, ows, new, york, city

Source: http://www.flickr.com/photos/smallhaystack/6534393249/

17 December 2011

Topics: occupy, wall, street, ows, new, york, city

Source: http://www.flickr.com/photos/smallhaystack/6534395019/

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93

Dec 16, 2011
12/11

Dec 16, 2011
by
Sirichai Chongchitnan; Joseph Silk

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What is the size of the most massive object one expects to find in a survey of a given volume? In this paper, we present a solution to this problem using Extreme-Value Statistics, taking into account primordial non-Gaussianity and its effects on the abundance and the clustering of rare objects. We calculate the probability density function (pdf) of extreme-mass clusters in a survey volume, and show how primordial non-Gaussianity shifts the peak of this pdf. We also study the sensitivity of the...

Source: http://arxiv.org/abs/1107.5617v2

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129

Dec 16, 2011
12/11

Dec 16, 2011
by
Pierre-Henri Chavanis

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We develop a kinetic theory of systems with long-range interactions taking collective effects and spatial inhomogeneity into account. Starting from the Klimontovich equation and using a quasilinear approximation, we derive a Lenard-Balescu-type kinetic equation written in angle-action variables. We confirm the result obtained by Heyvaerts [Mon. Not. R. Astron. Soc. {\bf 407}, 355 (2010)] who started from the Liouville equation and used the BBGKY hierarchy truncated at the level of the two-body...

Source: http://arxiv.org/abs/1107.1475v2

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58

Dec 16, 2011
12/11

Dec 16, 2011
by
Yong-Jun Zhang; Bin Zhang

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We study the proton and the Roper resonance together with the meson cloud model, by constructing a Hamiltonian matrix and solving the eigenvalue equation. The proton sea quark flavour asymmetry and some properties of the Roper resonance are thus reproduced in one scheme.

Source: http://arxiv.org/abs/1005.4550v2

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55

Dec 16, 2011
12/11

Dec 16, 2011
by
Jordi Fortuny; Bernat Corominas-Murtra

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We investigate both the locus of ambiguity in the architecture of language and the origin of ambiguity in natural communication. We 1) locate ambiguity at the externalization branch of language, 2) provide a rigorous, general definition of ambiguity through the concept of logical irreversibility, quantifying the amount of ambiguity within the framework of Shannon's information theory, and 3) provide a proof of concept that the constraints acting over a natural code force ambiguity to emerge....

Source: http://arxiv.org/abs/1107.0193v2

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115

Dec 16, 2011
12/11

Dec 16, 2011
by
Maryvonne Chalony; Anders Kastberg; Bruce Klappauf; David Wilkowski

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Doppler cooling on a narrow transition is limited by the noise of single scattering events. It shows novel features, which are in sharp contrast with cooling on a broad transition, such as a non-Gaussian momentum distribution, and divergence of its mean square value close to the resonance. We have observed those features using 1D cooling on an intercombination transition in strontium, and compared the measurements with theoretical predictions and Monte Carlo simulations. We also find that for a...

Source: http://arxiv.org/abs/1107.2313v2

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Dec 16, 2011
12/11

Dec 16, 2011
by
C. Trallero-Giner; V. Lopez-Richard; Y. Núñez-Fernández; Maurice Oliva; Ming-Chiang Chung

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Based on a unified theoretical treatment of the 1D Bogoliubov-de Genes equations, the superfluidity phenomenon of the Bose-Einstein condensates (BEC) loaded into trapped optical lattice is studied. Within the perturbation regime, an all-analytical framework is presented enabling a straightforward phenomenological mapping of the collective excitation and oscillation character of a trapped BEC where the available experimental configurations also fit.

Source: http://arxiv.org/abs/1107.4899v2

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91

Dec 16, 2011
12/11

Dec 16, 2011
by
Takuya Morozumi; Hiroyuki Takata; Kotaro Tamai

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We study a Dirac neutrino mass model of Davidson and Logan. In the model, the smallness of the neutrino mass is originated from the small vacuum expectation value of the second Higgs of two Higgs doublets. We study the one loop effective potential of the Higgs sector and examine how the small vacuum expectation is stable under the radiative correction. By deriving formulae of the radiative correction, we numerically study how large the one loop correction is and show how it depends on the...

Source: http://arxiv.org/abs/1107.1026v3

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56

Dec 16, 2011
12/11

Dec 16, 2011
by
Kazimierz Łakomy; Rejish Nath; Luis Santos

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Inter-site interactions play a crucial role in polar gases in optical lattices even in the absence of hopping. We show that due to these long-range interactions a destabilized stack of quasi-one dimensional Bose-Einstein condensates develops a correlated modulational instability in the non-overlapping sites. Interestingly, this density pattern may evolve spontaneously into soliton filaments or a crystal of solitons that can be so created for the first time in ultra-cold gases. These...

Source: http://arxiv.org/abs/1107.3132v2

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74

Dec 16, 2011
12/11

Dec 16, 2011
by
F. R. Klinkhamer

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A possible gluon-condensate-induced modified-gravity model with f(R) \propto |R|^{1/2} has been suggested previously. Here, a simplified version is presented using the constant flat-spacetime equilibrium value of the QCD gluon condensate and a single pressureless matter component (cold dark matter, CDM). The resulting dynamical equations of a spatially-flat and homogeneous Robertson-Walker universe are solved numerically. This simple empirical model allows, in fact, for a careful treatment of...

Source: http://arxiv.org/abs/1005.2885v7

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98

Dec 16, 2011
12/11

Dec 16, 2011
by
Michael Bate; Benjamin Martin; Gerhard Roehrle

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The aim of this paper is to describe an approach to a a strengthened form of J. Tits' Centre Conjecture for spherical buildings. This is accomplished by generalizing a fundamental result of G. R. Kempf from Geometric Invariant Theory and interpreting this generalization in the context of spherical buildings. We are able to recapture the conjecture entirely in terms of our generalization of Kempf's notion of a state. We demonstrate the utility of this approach by proving the Centre Conjecture in...

Source: http://arxiv.org/abs/1005.3212v3

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Dec 16, 2011
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Dec 16, 2011
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Ivan Nourdin

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In 2005, Nualart and Peccati showed that, surprisingly, the convergence in distribution of a normalized sequence of multiple Wiener-It\^o integrals towards a standard Gaussian law is equivalent to convergence of just the fourth moment to 3. Recently, this result has been extended to a sequence of multiple Wigner integrals, in the context of free Brownian motion. The goal of the present paper is to offer an elementary, unifying proof of these two results. The only advanced, needed tool is the...

Source: http://arxiv.org/abs/1107.3252v2

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Dec 15, 2011
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Dec 15, 2011
by
Dariusz Dereniowski

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It is proven that the connected pathwidth of any graph $G$ is at most $2\cdot\pw(G)+1$, where $\pw(G)$ is the pathwidth of $G$. The method is constructive, i.e. it yields an efficient algorithm that for a given path decomposition of width $k$ computes a connected path decomposition of width at most $2k+1$. The running time of the algorithm is $O(dk^2)$, where $d$ is the number of `bags' in the input path decomposition. The motivation for studying connected path decompositions comes from the...

Source: http://arxiv.org/abs/1007.1269v2

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Dec 15, 2011
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Dec 15, 2011
by
Margarida Melo; Filippo Viviani

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We compute the Picard groups of the universal Picard stack over the stack of smooth curves and of its compactification over the stack of stable curves. Along the way, we prove some results concerning the gerbe structure of the universal Picard stack over its rigidification by the natural action of the multiplicative group and relate this with the existence of generalized Poincar\'e line bundles. We also compare our results with Kouvidakis-Fontanari computations of the Picard group of the...

Source: http://arxiv.org/abs/1007.4519v3

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Dec 15, 2011
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Dec 15, 2011
by
Nick Evans; Keun-Young Kim; Maria Magou

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We explore the role of a holographic Wilsonian cut-off in simple probe brane models with chiral symmetry breaking/restoration phase transitions. The Wilsonian cut-off allows us to define supergravity solutions for off-shell configurations and hence to define a potential for the chiral condensate. We pay particular attention to the need for configurations whose action we are comparing to have the same IR and UV boundary conditions. We exhibit new first and second order phase transitions with...

Source: http://arxiv.org/abs/1107.5318v3

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Dec 15, 2011
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Dec 15, 2011
by
Feng Luo; Keith A. Olive; Jean-Philippe Uzan

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We consider the effect of the coupled variations of fundamental constants on the nucleon magnetic moment. The nucleon g-factor enters into the interpretation of the measurements of variations in the fine-structure constant, alpha, in both the laboratory (through atomic clock measurements) and in astrophysical systems (e.g. through measurements of the 21 cm transitions). A null result can be translated into a limit on the variation of a set of fundamental constants, that is usually reduced to...

Source: http://arxiv.org/abs/1107.4154v2