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September 2009 arXiv papers — page 13

Showing 1,2011,300 of 5,691 papers

  1. Eveline Legendre

    We provide an explicit resolution of the Abreu equation on convex labeled quadrilaterals. This confirms a conjecture of Donaldson in this particular case and implies a complete classification of the explicit toric Kähler-Einstein and toric Sasaki-Einstein metrics constructed in [6,22,14]. As a byproduct, we obtain a wealth of extremal toric (complex) orbi-su

  2. V. A. Avetisov, S. K. Nechaev

    We consider the dynamical system described by the area--preserving standard mapping. It is known for this system that $P(t)$, the normalized number of recurrences staying in some given domain of the phase space at time $t$ (so-clled "survival probability") has the power--law asymptotics, $P(t)\sim t^{-ν}$. We present new semi--phenomenological argume

  3. Hiraku Nozawa

    Let (M,F) be a closed manifold with a Riemannian foliation. We show that the secondary characteristic classes of the Molino's commuting sheaf of (M,F) vanish if (M,F) is developable and the fundamental group of M is of polynomial growth. By theorems of Álvarez López, our result implies that (M,F) is minimizable under the same conditions. As a corollary,

  4. Devavrat Shah, Tauhid Zaman

    We provide a systematic study of the problem of finding the source of a rumor in a network. We model rumor spreading in a network with a variant of the popular SIR model and then construct an estimator for the rumor source. This estimator is based upon a novel topological quantity which we term \textbf{rumor centrality}. We establish that this is an ML estim

  5. Rafael Ferraro

    Exterior calculus is a powerful tool to search for solutions to the electromagnetic field equations, whose strength can be better appreciated when applied to work out non-trivial configurations. Here we show how to exploit this machinery to obtain the electromagnetic TM and TE modes in hollow cylindrical waveguides. The proper use of exterior calculus and Lo

  6. Martin Hairer, Natesh S. Pillai

    We demonstrate that stochastic differential equations (SDEs) driven by fractional Brownian motion with Hurst parameter H > 1/2 have similar ergodic properties as SDEs driven by standard Brownian motion. The focus in this article is on hypoelliptic systems satisfying Hörmander's condition. We show that such systems satisfy a suitable version of the strong

  7. Elizabeth Gould, P. K. Aravind

    It is shown that the 33 complex rays in three dimensions used by Penrose to prove the Bell-Kochen-Specker theorem have the same orthogonality relations as the 33 real rays of Peres, and therefore provide an isomorphic proof of the theorem. It is further shown that the Peres and Penrose rays are just two members of a continuous three-parameter family of unita

  8. Simon Badger, E. W. Nigel Glover, Pierpaolo Mastrolia, Ciaran Williams

    We consider one-loop amplitudes of a Higgs boson coupled to gluons in the limit of a large top quark mass. We treat the Higgs as the real part of a complex field phi that couples to the self-dual field strengths and compute the one-loop corrections to the phi-NMHV amplitude, which contains one gluon of positive helicity whilst the remaining three have negati

  9. Chandra Chekuri, Jan Vondrak, Rico Zenklusen

    Motivated by several applications, we consider the problem of randomly rounding a fractional solution in a matroid (base) polytope to an integral one. We consider the pipage rounding technique and also present a new technique, randomized swap rounding. Our main technical results are concentration bounds for functions of random variables arising from these ro

  10. Marc Chemtob, Pierre Hosteins

    We search for supersymmetric standard model realizations with extra singlets and extra $ U(1)$ using the heterotic string compactification on the $ Z_{6-II}$ orbifold with two Wilson lines. We analyze the vacuum restabilization mechanism for three representative Pati-Salam string models obtained in the literature and present detailed results for the effectiv

  11. Yu Nakayama

    Scale invariant but non-conformal field theories are forbidden in (1+1) dimension, and so should be the corresponding holographic dual gravity theories. We conjecture that such scale invariant but non-conformal field configurations do not exist in the string/M-theory. We provide a proof of this conjecture in the classical supergravity limit under a certain g

  12. Valentino Tosatti, Ben Weinkove

    We generalize Yau's estimates for the complex Monge-Ampere equation on compact manifolds in the case when the background metric is no longer Kahler. We prove $C^{\infty}$ a priori estimates for a solution of the complex Monge-Ampere equation when the background metric is Hermitian (in complex dimension two) or balanced (in higher dimensions), giving an a

  13. X. N. Zhang, K. -Y. Choi, P. Lemmens, T. Nakajima

    We report on Raman scattering measurements of the A-site ordered YBaMn2O6 in the wide temperature range of 10-650K. Upon cooling almost all phonon modes show pronounced temperature dependencies of frequency, linewidth, and scattering intensity. This suggests that the octahedra tilting, Mn-O bond angles and lengths vary with temperature in a concerted way. Th

  14. Oscar Garcia-Prada, Peter B. Gothen, Ignasi Mundet i Riera

    We develop a complete Hitchin-Kobayashi correspondence for twisted pairs on a compact Riemann surface X. The main novelty lies in a careful study of the the notion of polystability for pairs, required for having a bijective correspondence between solutions to the Hermite-Einstein equations, on one hand, and polystable pairs, on the other. Our results allow u

  15. Massimo Mannarelli, Cristina Manuel

    We consider the phonon contribution to the bulk viscosities $ζ_1, ζ_2$ and $ζ_3$ of a cold relativistic superfluid. We assume the low temperature $T$ regime and that the transport properties of the system are dominated by the phonons. We use kinetic theory in the relaxation time approximation and the low energy effective field theory of the corresponding sys

  16. Joel C. Miller

    Recent work by Erik Volz [arXiv:0705.2092] has shown how to calculate the growth and eventual decay of an SIR epidemic on a static random network, assuming infection and recovery each happen at constant rates. This calculation allows us to account for effects due to heterogeneity in degree that are neglected in the standard mass-action SIR equations. In this

  17. Tuomas P. Hytönen

    As a step in developing a non-commutative Calderon-Zygmund theory, J. Parcet (J. Funct. Anal., 2009) established a new pseudo-localisation principle for classical singular integrals, showing that Tf has small L^2 norm outside a set which only depends on f in L^2 but not on the arbitrary normalised Calderon-Zygmund operator T. Parcet also asked if a similar r

  18. Ling Bao, Axel Kleinschmidt, Bengt E. W. Nilsson, Daniel Persson

    The hypermultiplet moduli space in Type IIA string theory compactified on a rigid Calabi-Yau threefold X, corresponding to the "universal hypermultiplet", is described at tree-level by the symmetric space SU(2,1)/(SU(2) x U(1)). To determine the quantum corrections to this metric, we posit that a discrete subgroup of the continuous tree-level isometr

  19. Elham Kashefi, Damian Markham, Mehdi Mhalla, Simon Perdrix

    The entangled graph states have emerged as an elegant and powerful quantum resource, indeed almost all multiparty protocols can be written in terms of graph states including measurement based quantum computation (MBQC), error correction and secret sharing amongst others. In addition they are at the forefront in terms of implementations. As such they represen

  20. Qi Guo, Simon White, Cheng Li, Michael Boylan-Kolchin

    For any assumed stellar Initial Mass Function, the Sloan Digital Sky Survey (SDSS) gives a precise determination of the stellar mass function of galaxies for 10^8 M_sun < M_* < 10^12 M_sun. Within the concordance LCDM cosmology, the Millennium simulations give a precise halo mass function for all halos within which galaxies can form. Under the plausible hypo

  21. J. A. Morgan

    An approach to land surface temperature (LST) estimation that relies upon Bayesian inference has been tested against multiband infrared radiometric imagery from the Terra MODIS instrument. Bayesian LST estimators are shown to reproduce standard MODIS product LST values starting from a parsimoniously chosen (hence, uninformative) range of prior band emissivit

  22. R. Fiore, N. N. Nikolaev, V. R. Zoller

    The asymptotic freedom is known to split the leading-$\log$ BFKL pomeron into a series of isolated poles in the complex angular momentum plane. One of our earlier findings was that the subleading hard BFKL exchanges decouple from such experimentally important observables as small-$x$ charm, $F_2^c$, and the longitudinal, $F_L$, structure functions of the pro

  23. Maciej Borodzik

    We study deformations of plane curve singularities from an analytic point of view and obtain some new concrete results. We show some rather unexpected properties of Puiseux coefficients treated as functions on a suitably defined parameter space. The methods used in paper are very elementary.

  24. Vladimir V. Kisil

    In the search for hypercomplex analytic functions on the half-plane, we review the construction of induced representations of the group G=SL(2,R). Firstly we note that G-action on the homogeneous space G/H, where H is any one-dimensional subgroup of SL(2,R), is a linear-fractional transformation on hypercomplex numbers. Thus we investigate various hypercompl

  25. Adam Wardlow

    A recent paper proposes a way of constructing infinite dimensional symmetries of the non-supersymmetric self-dual Yang-Mills action using isometries of the space-time. We review the Lagrangian formulation of N = 4 super Yang-Mills MHV rules and extend the approach taken for the non-supersymmetric case to construct infinite dimensional symmetries of self-dual

  26. Sergei Sakovich

    The Hunter-Saxton equation and the Gurevich-Zybin system are considered as two mutually non-equivalent representations of one and the same Whitham-type equation, and all their common solutions are obtained exactly.

  27. Julia Evans, Ross Duncan, Alex Lang, Prakash Panangaden

    Finding all the mutually unbiased bases in various dimensions is a problem of fundamental interest in quantum information theory and pure mathematics. The general problem formulated in finite-dimensional Hilbert spaces is open. In the categorical approach to quantum mechanics one can find examples of categories which behave ``like&#39;&#39; the category of f

  28. Preeti Parashar, Swapan Rana

    We calculate the analytic expression for geometric measure of entanglement for arbitrary superposition of two $N$-qubit canonical orthonormal Greenberger-Horne-Zeilinger ($GHZ$) states and the same for two $W$ states. In course of characterizing all kinds of nonclassical correlations, explicit formula for quantum discord (via relative entropy) for the former

  29. Osamu Fujino

    In this paper, we prove the cone theorem and the contraction theorem for pairs $(X, B)$, where $X$ is a normal variety and $B$ is an effective $\mathbb R$-divisor on $X$ such that $K_X+B$ is $\mathbb R$-Cartier.

  30. Nicolas Destainville

    We discuss a realistic scenario, accounting for the existence of sub-micrometric protein domains in cell membranes. At the biological level, such membrane domains have been shown to be specialized, in order to perform a determined biological task, in the sense that they gather one or a few protein species out of the hundreds of different ones that a cell mem

  31. Wolfgang Bertram, Michael Kinyon

    For all classical groups (and for their analogs in infinite dimension or over general base fields or rings) we construct certain contractions, called &#34;homotopes&#34;. The construction is geometric, using as ingredient involutions of associative geometries. We prove that, under suitable assumptions, the groups and their homotopes have a canonical semigrou

  32. Carlos Hernandez-Monteagudo

    In the context of the study of the ISW, we revisit the angular cross correlation of WMAP CMB data with the NVSS radio survey. We compute 2-point cross functions between the two surveys in real and in Fourier space, paying particular attention on the dependence of results on the flux of NVSS radio sources, the angular scales where correlations arise and the c

  33. Andreas Faltenbacher, Simon D. M. White

    Based on the Millennium Simulation we examine assembly bias for the halo properties: shape, triaxiality, concentration, spin, shape of the velocity ellipsoid and velocity anisotropy. For consistency we determine all these properties using the same set of particles, namely all gravitationally self-bound particles belonging to the most massive sub-structure of

  34. Iustin Coanda

    We are concerned with the problem of the stability of the syzygy bundles associated to base point free vector spaces of forms of the same degree d on the projective space of dimension n. We deduce directly, from Mark Green&#39;s vanishing theorem for Koszul cohomology, that any such bundle is stable if his rank is sufficiently high. With a similar argument,

  35. R. Daou, J. Chang, David LeBoeuf, Olivier Cyr-Choiniere

    The nature of the pseudogap phase is a central problem in the quest to understand high-Tc cuprate superconductors. A fundamental question is what symmetries are broken when that phase sets in below a temperature T*. There is evidence from both polarized neutron diffraction and polar Kerr effect measurements that time- reversal symmetry is broken, but at temp

  36. Konstantin T. Matchev, Filip Moortgat, Luc Pape, Myeonghun Park

    The inclusive same-sign dilepton channel is already recognized as a promising discovery signature for supersymmetry in the early days of the LHC. We point out that it can also be used for precision measurements of sparticle masses after the initial discovery. As an illustration, we consider the LM6 CMS study point in minimal supergravity, where the same-sign

  37. G. Tkachov, E. M. Hankiewicz

    The quantum spin Hall (QSH) state, observed in a zero magnetic field in HgTe quantum wells, respects the time-reversal symmetry and is distinct from quantum Hall (QH) states. We show that the QSH state persists in strong quantizing fields and is identified by counter-propagating (helical) edge channels with nonlinear dispersion inside the band gap. If the Fe

  38. Olof Gornerup, Magnus Boman

    A content-based network representation of web logs (blogs) using a basic word-overlap similarity measure is presented. Due to a strong signal in blog data the approach is sufficient for accurately classifying blogs. Using Swedish blog data we demonstrate that blogs that treat similar subjects are organized in clusters that, in turn, are hierarchically organi

  39. M. Viola, M. Maturi, M. Bartelmann

    We construct two linear filtering techniques based on weak gravitational lensing to constrain the inner slope $α$ of the density profile of dark-matter halos. Both methods combine all available information into an estimate of this single number. Under idealised assumptions, $α$ is constrained to ~15% if the halo concentration c is known, and to < 30% if not.

  40. Istvan Mezo

    The notion of generalized Bell numbers has appeared in several works but there is no systematic treatise on this topic. In this paper we fill this gap. We discuss the most important combinatorial, algebraic and analytic properties of these numbers which generalize the similar properties of the Bell numbers. Most of these results seem to be new. It turns out

  41. Vinesh Solanki, Dmitry Sustretov, Boris Zilber

    We carry out a model-theoretic analysis of the Heisenberg algebra. To this end, a geometric structure is associated to the Heisenberg algebra and is shown to be a Zariski geometry. Furthermore, this Zariski geometry is shown to be non-classical, in the sense that it is not interpretable in an algebraically closed field. On assuming self-adjointness of the po

  42. Renata jora, Joseph Schechter, M. Naeem Shahid

    We study the effects of the perturbation which violates the permutation symmetry of three Majorana neutrinos but preserves the well known (23) interchange symmetry. This is done in the presence of an arbitrary Majorana phase which serves to insure the degeneracy of the three neutrinos at the unperturbed level.

  43. Nils Bergvall, Erik Zackrisson, Brady Caldwell

    The faint stellar halos of galaxies contain key information about the oldest stars and the process of galaxy formation. A previous study of stacked SDSS images of disk galaxies has revealed a halo with an abnormally red r-i colour, seemingly inconsistent with our current understanding of stellar halos. Here, we investigate the statistical properties of the f

  44. Simon Brain, Giovanni Landi

    Using the theory of noncommutative geometry in a braided monoidal category, we improve upon a previous construction of noncommutative families of instantons of arbitrary charge on the deformed sphere S^4_θ. We formulate a notion of noncommutative parameter spaces for families of instantons and we explore what it means for such families to be gauge equivalent

  45. Haim Diamant, Oded Agam

    A qualitatively different manifestation of the Rayleigh instability is demonstrated, where, instead of the usual extended undulations and breakup of the liquid into many droplets, the instability is localized, leading to an isolated narrowing of the liquid filament. The localized instability, caused by a nonuniform curvature of the liquid domain, plays a key

  46. Kazuharu Bamba, Chao-Qiang Geng, Shin&#39;ichi Nojiri, Sergei D. Odintsov

    We explicitly show that the equations of motion for modified gravity theories of $F(R)$-gravity, the scalar-Gauss-Bonnet gravity, $F(\mathcal{G})$-gravity and the non-local gravity are equivalent to the Clausius relation in thermodynamics. In addition, we discuss the relation between the expression of the entropy and the contribution from the modified gravit

  47. Martin Hoferichter, Bastian Kubis, Ulf-G. Meißner

    We calculate isospin breaking in pion-nucleon scattering in the threshold region in the framework of covariant baryon chiral perturbation theory. All effects due to quark mass differences as well as real and virtual photons are consistently included. As an application, we discuss the energy dependence of the triangle relation that connects elastic scattering

  48. Nicholas D. Alikakos

    We rewrite the system Δu - W_u (u) = 0, for u: R^n to R^n, in the form div T = 0, where T is an appropriate stress-energy tensor, and derive certain a priori consequences on the solutions. In particular, we point out some differences between two paradigms: the phase-transition system, with target a finite set of points, and the Ginzburg-Landau system, with t

  49. D. A. Rodrigues, A. D. Armour

    We analyze the amplitude and phase noise of limit-cycle oscillations in a mechanical resonator coupled parametrically to an optical cavity driven above its resonant frequency. At a given temperature the limit-cycle oscillations have lower amplitude noise than states of the same average amplitude excited by a pure harmonic drive; for sufficiently low thermal

  50. Victor Yakhot

    A global approach to analysis of fully developed turbulent flows in pipes/channels and zero pressure gradient boundary layers is proposed. A new dynamic definition of the boundary layer thickness $δ(x)$, where $x$ is the distance to the plate origin, is proposed. The Coles - Fernholtz empirical correlation for skin friction $λ=\frac{2τ_{w}}{ρU_{0}^{2}}\propt

  51. Nils Carqueville, Ingo Runkel

    We investigate tensor products of matrix factorisations. This is most naturally done by formulating matrix factorisations in terms of bimodules instead of modules. If the underlying ring is C[x_1,...,x_N] we show that bimodule matrix factorisations form a monoidal category. This monoidal category has a physical interpretation in terms of defect lines in a tw

  52. Ofer Yuli, Itay Asulin, Gad Koren, Oded Millo

    Using scanning tunneling spectroscopy we have investigated the spatial evolution of the anomalous c-axis zero bias conductance peak, discovered in a previous study by our group, in epitaxial La$_{1.88}$Sr$_{0.12}$CuO$_4$ thin films. We found an anisotropic spatial dependence of the corresponding low-energy density of states which complies with the predicted

  53. Chee Kwan Gan, David J. Srolovitz

    We use density functional theory to determine the equilibrium shape of graphene flakes, through the calculation of the edge orientation dependence of the edge energy and edge stress of graphene nanoribbons. The edge energy is a nearly linear function of edge orientation angle; increasing from the armchair orientation to the zigzag orientation. Reconstruction

  54. Takeshi Chiba

    We derive the equation of state of tracker fields, which are typical examples of freezing quintessence (quintessence with the equation of state approaching toward -1), taking into account of the late-time departure from the tracker solution due to the nonzero density parameter of dark energy $\Omp$. We calculate the equation of state as a function of $\Omp$

  55. Rohit verma, Gulsheen Ahuja, Manmohan Gupta

    In the context of Fritzsch-like texture 4 zero Hermitian quark mass matrices, we have attempted to find an `exact' formula for sin2\beta wherein the dependence of \beta on the quark masses and the elements of the quark mass matrices is visible in a simple and clear manner. This has been achieved keeping in mind the strong hierarchy of the quark masses and as

  56. Gábor Hetyei

    We show how Viennot&#39;s combinatorial theory of orthogonal polynomials may be used to generalize some recent results of Sukumar and Hodges on the matrix entries in powers of certain operators in a representation of su(1,1). Our results link these calculations to finding the moments and inverse polynomial coefficients of certain Laguerre polynomials and Mei

  57. Gady Kozma, Asaf Nachmias

    In this note we study the geometry of the largest component C_1 of critical percolation on a finite graph G which satisfies the finite triangle condition, defined by Borgs et al. There it is shown that this component is of size n^{2/3}, and here we show that its diameter is n^{1/3} and that the simple random walk takes n steps to mix on it. Our results apply

  58. A. Buica, J. Llibre, O. Makarenkov

    By a nondegenerate $k$-parameterized family $K$ of periodic solutions we understand the situation when the geometric multiplicity of the multiplier +1 of the linearized on $K$ system equals to $k.$ Bifurcation of asymptotically stable periodic solutions from $K$ is well studied in the literature and different conditions have been proposeddepending on whether

  59. Joseph E. Bonin

    A lattice path matroid is a transversal matroid for which some collection of incomparable intervals in some linear order on the ground set is a presentation. We characterize the minor-closed class of lattice path matroids by its excluded minors.

  60. Alice Medvedev, Ramin Takloo-Bighash

    We carry out some of Galois&#39;s work in the setting of an arbitrary first-order theory T. We replace the ambient algebraically closed field by a large model M of T, replace fields by definably closed subsets of M, assume that T codes finite sets, and obtain the fundamental duality of Galois theory matching subgroups of the Galois group of L over F with int

  61. David J. Aldous

    We review old and new uses of exchangeability, emphasizing the general theme of exchangeable representations of complex random structures. Illustrations of this theme include processes of stochastic coalescence and fragmentation; continuum random trees; second-order limits of distances in random graphs; isometry classes of metric spaces with probability meas

  62. Zhibin Du, Bo Zhou

    We determine the minimum sum--connectivity index of bicyclic graphs with $n$ vertices and matching number $m$, where $2\le m\le \lfloor\frac{n}{2}\rfloor$, the minimum and the second minimum, as well as the maximum and the second maximum sum--connectivity indices of bicyclic graphs with $n\ge 5$ vertices. The extremal graphs are characterized.

  63. Chris T. K. Ng, Howard Huang

    A simple line network model is proposed to study the downlink cellular network. Without base station cooperation, the system is interference-limited. The interference limitation is overcome when the base stations are allowed to jointly encode the user signals, but the capacity-achieving dirty paper coding scheme can be too complex for practical implementatio

  64. Yaming Yu

    We investigate stochastic comparisons between exponential family distributions and their mixtures with respect to the usual stochastic order, the hazard rate order, the reversed hazard rate order, and the likelihood ratio order. A general theorem based on the notion of relative log-concavity is shown to unify various specific results for the Poisson, binomia

  65. Amos Fiat, Amiram Wingarten

    We study the envy free pricing problem faced by a seller who wishes to maximize revenue by setting prices for bundles of items. If there is an unlimited supply of items and agents are single minded then we show that finding the revenue maximizing envy free allocation/pricing can be solved in polynomial time by reducing it to an instance of weighted independe

  66. Denis A. Areshkin, Branislav K. Nikolic

    The recent fabrication of graphene nanoribbon (GNR) field-effect transistors poses a challenge for first-principles modeling of carbon nanoelectronics due to many thousand atoms present in the device. The state of the art quantum transport algorithms, based on the nonequilibrium Green function formalism combined with the density functional theory (NEGF-DFT),

  67. Alexander Dranishnikov

    We prove that $$ \cat X\le cd(π_1(X))+\bigg\lceil\frac{\dim X-1}{2}\bigg\rceil$$ for every CW complex $X$ where $cd(π_1(X))$ denotes the cohomological dimension of the fundamental group of $X$.

  68. Shengfeng Cheng, Binquan Luan, Mark O. Robbins

    Molecular dynamics simulations are used to study contact between a rigid, nonadhesive, spherical tip with radius of order 30nm and a flat elastic substrate covered with a fluid monolayer of adsorbed chain molecules. Previous studies of bare surfaces showed that the atomic scale deviations from a sphere that are present on any tip constructed from discrete at

  69. Ashfaque H. Bokhari, Ahmad Y. Dweik, F. D. Zaman, A. H. Kara

    In a recent work [1, 2] Sjoberg remarked that generalization of the double reduction theory to partial differential equations of higher dimensions is still an open problem. In this note we have attempted to provide this generalization to find invariant solution for a non linear system of qth order partial differential equations with n independent and m depen

  70. Ziqin Feng, Paul Gartside

    A family $\bfam$ of continuous real-valued functions on a space $X$ is said to be {\sl basic} if every $f \in C(X)$ can be represented $f = \sum_{i=1}^n g_i \circ ϕ_i$ for some $ϕ_i \in \bfam$ and $g_i \in C(\R)$ ($i=1, ..., n$). Define $\basic (X) = \min \{|\bfam| : \bfam$ is a basic family for $X\}$. If $X$ is separable metrizable $X$ then either $X$ is lo

  71. Mahouton Norbert Hounkonnou, Dine Ousmane Samary

    This paper addresses the computation of Noether currrents for the renormalizable Grosse-Wulkenhaar (GW) $ϕ^{\star 4}$ model subjected to a dynamical noncomutativity realized through a twisted Moyal product. The noncommutative (NC) energy-momentum tensor (EMT), angular momentum tensor (AMT) and the dilatation current (DC) are explicitly derived. The breaking

  72. Ziqin Feng, Paul Gartside

    Every continuous function of two or more real variables can be written as the superposition of continuous functions of one real variable along with addition.

  73. Luis Salas, Irene Cruz-Gonzalez

    We applied the extinction-disk-principal vectors approach to near infrared photometric data of the Taurus-Auriga region and Orion Nebula young stellar clusters. By assuming that the cluster age is represented by the median value of the age distribution we are able to derive the distribution of stellar masses. We showed that the resulting initial mass functio

  74. Gautam Chinta, Paul E. Gunnells

    We formulate a conjecture for the local parts of Weyl group multiple Dirichlet series attached to root systems of type D. Our conjecture is analogous to the description of the local parts of type A series given by Brubaker, Bump, Friedberg, and Hoffstein in terms of Gelfand--Tsetlin patterns. Our conjecture is given in terms of patterns for irreducible repre

  75. G. K. Skinner, G. H. Freeman

    Models in which the number of goals scored by a team in a soccer match follow a Poisson distribution, or a closely related one, have been widely discussed. We here consider a soccer match as an experiment to assess which of two teams is superior and examine the probability that the outcome of the experiment (match) truly represents the relative abilities of

  76. S. Paardekooper, C. Baruteau, A. Crida, W. Kley

    We study the torque on low-mass planets embedded in protoplanetary discs in the two-dimensional approximation, incorporating non-isothermal effects. We couple linear estimates of the Lindblad (or wave) torque to a simple, but non-linear, model of adiabatic corotation torques (or horseshoe drag), resulting in a simple formula that governs Type I migration in

  77. Yaakov Malinovsky, Yosef Rinott

    Prediction of a vector of ordered parameters or part of it arises naturally in the context of Small Area Estimation (SAE). For example, one may want to estimate the parameters associated with the top ten areas, the best or worst area, or a certain percentile. We use a simple SAE model to show that estimation of ordered parameters by the corresponding ordered

  78. Matthew R. Buckley, Lisa Randall, Brian Shuve

    Because the TeV-scale to be probed at the Large Hadron Collider should shed light on the naturalness, hierarchy, and dark matter problems, most searches to date have focused on new physics signatures motivated by possible solutions to these puzzles. In this paper, we consider some candidates for new states that although not well-motivated from this standpoin

  79. Arne Rau, Gijs H. A. Roelofs, Paul J. Groot, Tom R. Marsh

    We present three new candidate AM CVn binaries, plus one confirmed new system, from a spectroscopic survey of color-selected objects from the Sloan Digital Sky Survey. All four systems were found from their helium emission lines in low-resolution spectra taken on the Hale telescope at Palomar, and the Nordic Optical Telescope and the William Herschel Telesco

  80. Jeff Cooke

    The spectral properties of Lyman break galaxies (LBGs) offer a means to isolate pure samples displaying either dominant Ly-alpha in absorption or Ly-alpha in emission using broadband information alone. We present criteria developed using a large z ~ 3 LBG spectroscopic sample from the literature that enables large numbers of each spectral type to be gathered

  81. Guillermo Torres, Claud H. Sandberg Lacy, Antonio Claret

    We report extensive spectroscopic and differential V-band photometric observations of the 18.4-day detached double-lined eclipsing binary LV Her (F9V), which has the highest eccentricity (e = 0.613) among the systems with well-measured properties. We determine the absolute masses and radii of the components to be M1 = 1.193 +/- 0.010 M(Sun), M2 = 1.1698 +/-

  82. Eric L. Nielsen, Laird M. Close

    We expand on the results of Nielsen et al. (2008), using the null result for giant extrasolar planets around the 118 target stars from the VLT NACO H and Ks band planet search (Masciadri et al. 2005), the VLT and MMT Simultaneous Differential Imaging (SDI) survey (Biller et al. 2007), and the Gemini Deep Planet Survey (Lafreniere et al. 2007) to set constrai

  83. P. Athron, S. F. King, R. Luo, D. J. Miller

    We argue that in the two-loop approximation gauge coupling unification in the exceptional supersymmetric standard model can be achieved for any phenomenologically reasonable value of strong gauge coupling at the electroweak scale consistent with the experimentally measured central value.

  84. V. S. Buslaev, S. B. Levin, P. Neittaanmäki, T. Ojala

    Basing on analogy between the three-body scattering problem and the diffraction problem of the plane wave (for the case of the short range pair potentials) by the system of six half transparent screens, we presented a new approach to the few-body scattering problem. The numerical results have been obtained for the case of the short range nonnegative pair pot

  85. Alexander P. Bakulev

    Using the results on the electromagnetic pion Form Factor (FF) obtained in the $O(α_s)$ QCD sum rules with non-local condensates \cite{BPS09} we determine the effective continuum threshold for the local duality approach. Then we apply it to construct the $O(α_s^2)$ estimation of the pion FF in the framework of the fractional analytic perturbation theory.

  86. P. D. Diago, J. Gutierrez-Soto, M. Auvergne, J. Fabregat

    The presence of pulsations in late-type Be stars is still a matter of controversy. It constitutes an important issue to establish the relationship between non-radial pulsations and the mass-loss mechanism in Be stars. To contribute to this discussion, we analyse the photometric time series of the B8IVe star HD 50209 observed by the CoRoT mission in the seism

  87. M. Ciafaloni, D. Colferai

    Starting from the semiclassical reduced-action approach to transplanckian scattering by Amati, Veneziano and one of us and from our previous quantum extension of that model, we investigate the S-matrix expression for inelastic processes by extending to this case the tunneling features previously found in the region of classical gravitational collapse. The re

  88. J. Agostinho Moreira, A. Almeida, W. S. Ferreira, M. R. Chaves

    Eu1-xYxMnO3 exhibits, unlike other magnetoelectric systems, very distinctive features. Its magnetoelectric properties is driven by the magnetic spin of the Mn3+ ion, but they can be drastically changed by varying the content of Y3+, which it does not carry any magnetic moment. Though the x = 0.40 composition has been studied extensively, some basic questions

  89. A. Hoffman, J. D. Wright

    We study the weak interaction between a pair of well-separated coherent structures in possibly non-local lattice differential equations. In particular we prove that if a lattice differential equation in one space dimension has asymptotically stable (in the sense of Chow, Mallet-Paret and Shen) traveling wave solutions whose profiles approach limiting equilib

  90. R. L. Silva, A. R. Pereira, W. A. Moura-Melo

    We consider a nanodisk possessing two coupled materials with different ferromagnetic exchange constant. The common border line of the two media passes at the disk center dividing the system exactly in two similar half-disks. The vortex core motion crossing the interface is investigated with a simple description based on a two-dimensional model which mimics a

  91. José I. Orlicki

    Delving into present trends and anticipating future malware trends, a hybrid, SQL on the server-side, JavaScript on the client-side, self-replicating worm based on two-stage quines was designed and implemented on an ad-hoc scenario instantiating a very common software pattern. The proof of concept code combines techniques seen in the wild, in the form of SQL

  92. R. L. Silva, A. R. Pereira, W. A. Moura-Melo, R. C. Silva

    We investigate the influence of artificial defects (small holes) inserted into magnetic nanodisks on the vortex core dynamics. One and two holes (antidots) are considered. In general, the core falls into the hole but, in particular, we would like to remark an interesting phenomenon not yet observed, which is the vortex core switching induced by the vortex-ho

  93. L. Zhang, Q. -R. Yuan, X. Zhou, Z. -J. Jiang

    An optical photometric observation with the Beijing-Arizona-Taiwan-Connecticut (BATC) multicolor system is carried out for A98 (z=0.104), a galaxy cluster with two large enhancements in X-ray surface brightness. The spectral energy distributions (SEDs) covering 15 intermediate bands are obtained for all sources detected down to V ~ 20 mag in a field of $58&#

  94. Sahand Jamal Rahi, Saad Zaheer

    We investigate a stable Casimir force configuration consisting of an object contained inside a spherical or spheroidal cavity filled with a dielectric medium. The spring constant for displacements from the center of the cavity and the dependence of the energy on the relative orientations of the inner object and the cavity walls are computed. We find that the

  95. William Cherry

    Lecture 1 discusses non-Archimedean analogs of classical complex function theory based on the Schnirelman integral. Lecture 2 discusses valuation (Newton) polygons and their consequences and presents a non-Archimedean analog of the Poisson-Jensen formula. Lecture 3 introduces non-Archimedean value distribution theory. Lecture 4 presents an introduction to Be

  96. Ivan H. Deutsch, Poul S. Jessen

    Quantum control and measurement are two sides of the same coin. To affect a dynamical map, well-designed time-dependent control fields must be applied to the system of interest. To read out the quantum state, information about the system must be transferred to a probe field. We study a particular example of this dual action in the context of quantum control

  97. Matt Mountain, Roeland van der Marel, Remi Soummer, Anton Koekemoer

    Ground-based adaptive optics (AO) in the infrared has made exceptional advances in approaching space-like image quality at higher collecting area. Optical-wavelength applications are now also growing in scope. We therefore provide here a comparison of the pros and cons of observational capabilities from the ground and from space at optical wavelengths. With

  98. Joseph D. Masters, Xingru Zhang

    We show that every hyperbolic link complement contains closed quasi-Fuchsian surfaces. As a consequence, we obtain the result that on a hyperbolic link complement, if we remove from each cusp of the manifold a certain finite set of slopes, then all remaining Dehn fillings on the link complement yield manifolds with closed immersed incompressible surfaces.

  99. W. Barreto, L. Castillo, E. Barrios

    We study the evolution of a perfect--fluid sphere coupled to a scalar radiation field. By ensuring a Ricci invariant regularity as a conformally flat spacetime at the central world line we find that the fluid coupled to the scalar field satisfies the equation of state $ρ_c+3p_c=$ constant at the center of the sphere, where the energy $ρ_c$ density and the pr

  100. Stanislav Smirnov

    We study scaling limits and conformal invariance of critical site percolation on triangular lattice. We show that some percolation-related quantities are harmonic conformal invariants, and calculate their values in the scaling limit. As a particular case we obtain conformal invariance of the crossing probabilities and Cardy&#39;s formula. Then we prove exist