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September 2009 arXiv papers — page 36

Showing 3,5013,600 of 5,691 papers

  1. Gui-Jun Ding

    We present a supersymmetric model of quark and lepton based on $S_4\times Z_3\times Z_4$ flavor symmetry. The $S_4$ symmetry is broken down to Klein four and $Z_3$ subgroups in the neutrino and the charged lepton sectors respectively. Tri-Bimaximal mixing and the charged lepton mass hierarchies are reproduced simultaneously at leading order. Moreover, a real

  2. Andrew Smerald, Nic Shannon

    We present a phenomenological, two-fluid approach to understanding the magnetic excitations in Fe pnictides, in which a paramagnetic fluid with gapless, incoherent particle-hole excitations coexists with an antiferromagnetic fluid with gapped, coherent spin wave excitations. We show that this two-fluid phenomenology provides an excellent quantitative descrip

  3. Tamas Geszti

    Closed expressions are derived for the quantum measurement statistics of pre-and postselected gaussian particle beams. The weakness of the pre-selection step is shown to compete with the non-orthogonality of post-selection in a transparent way. The approach is shown to be useful in analyzing post-selection-based signal amplification, allowing measurements to

  4. Christophe Texier, Christian Hagendorf

    The average density of states (DoS) of the one-dimensional Dirac Hamiltonian with a random mass on a finite interval [0,L] is derived. Our method relies on the eigenvalues distributions (extreme value statistics problem) which are explicitly obtained. The well-known Dyson singularity <rho(epsilon;L)>\sim-L/|epsilon|ln^3|ε| is recovered above the crossover en

  5. François Gay-Balmaz, Cesare Tronci

    We formulate Euler-Poincaré and Lagrange-Poincaré equations for systems with broken symmetry. We specialize the general theory to present explicit equations of motion for nematic systems, ranging from single nematic molecules to biaxial liquid crystals. The geometric construction applies to order parameter spaces consisting of either unsigned unit vectors (d

  6. R. Winkler, U. Zülicke

    We show that pseudo-spin 1/2 degrees of freedom can be categorized in two types according to their behavior under time reversal. One type exhibits the properties of ordinary spin whose three Cartesian components are all odd under time reversal. For the second type, only one of the components is odd while the other two are even. We discuss several physical ex

  7. A. Esteban-Pretel, R. Tomas, J. W. F. Valle

    We consider the effect of non-standard neutrino interactions (NSI, for short) on the propagation of neutrinos through the supernova (SN) envelope within a three-neutrino framework and taking into account the presence of a neutrino background. We find that for given NSI parameters, with strength generically denoted by $\varepsilon_{ij}$, neutrino evolution ex

  8. P. Petit, B. Dintrans, A. Morgenthaler, V. Van Grootel

    Aims. We investigate the long-term evolution of the large-scale photospheric magnetic field geometry of the solar-type star HD 190771. With fundamental parameters very close to those of the Sun except for a shorter rotation period of 8.8 d, HD 190771 provides us with a first insight into the specific impact of the rotation rate in the dynamo generation of ma

  9. R. Arnaldi, P. Cortese, E. Scomparin

    The observation of an anomalous jpsi suppression in nucleus-nucleus collisions is one of the most important results of the SPS heavy-ion program. An essential ingredient in this result is the determination, obtained by studying p-A collisions, of effects not related with the formation of a deconfined medium. These effects are extrapolated to A-A collisions,

  10. Dijana Jakelic, Adriano Moura

    We establish several results concerning tensor products, q-characters, and the block decomposition of the category of finite-dimensional representations of quantum affine algebras in the root of unity setting. In the generic case, a Weyl module is isomorphic to a tensor product of fundamental representations and this isomorphism was essential for establishin

  11. M. Trichas, M. Rowan-Robinson, A. Georgakakis, I. Valtchanov

    We present the largest spectroscopic follow-up performed in SWIRE ELAIS-N1. We were able to determine redshifts for 289 extragalactic sources. The values of spectroscopic redshifts of the latter have been compared with the estimated values from our photometric redshift code with very good agreement between the two for both galaxies and quasars. Six of the qu

  12. Luca Lepori, Gabor Zsolt Toth, Gesualdo Delfino

    The three-state Potts field theory in two dimensions with thermal and magnetic perturbations provides the simplest model of confinement allowing for both mesons and baryons, as well as for an extended phase with deconfined quarks. We study numerically the evolution of the mass spectrum of this model over its whole parameter range, obtaining a pattern of conf

  13. Robin Girard

    This paper gives a theoretical analysis of high dimensional linear discrimination of Gaussian data. We study the excess risk of linear discriminant rules. We emphasis on the poor performances of standard procedures in the case when dimension p is larger than sample size n. The corresponding theoretical results are non asymptotic lower bounds. On the other ha

  14. Özlem Beyarslan, Ehud Hrushovski

    We study the automorphism group of the algebraic closure of a substructure A of a pseudo-finite field F. We show that the behavior of this group, even when A is large, depends essentially on the roots of unity in F. For almost all completions of the theory of pseudo-finite fields we show that algebraic closure agrees with definable closure, as soon as A cont

  15. Cristina Bertone, Paolo Lella, Margherita Roggero

    Let $p(t)$ be an admissible Hilbert polynomial in $\PP^n$ of degree $d$. The Hilbert scheme $\hilb^n_p(t)$ can be realized as a closed subscheme of a suitable Grassmannian $ \mathbb G$, hence it could be globally defined by homogeneous equations in the Plucker coordinates of $ \mathbb G$ and covered by open subsets given by the non-vanishing of a Plucker coo

  16. Pavel Chigansky, Yaacov Ritov

    This paper deals with convergence of the maximum a posterior probability path estimator in hidden Markov models. We show that when the state space of the hidden process is continuous, the optimal path may stabilize in a way which is essentially different from the previously considered finite-state setting.

  17. Nenad Vukmirovic, Vladimir M. Stojanovic, Mihajlo Vanevic

    We study graphene antidot lattices -- superlattices of perforations (antidots) in a graphene sheet -- using a model that accounts for the phonon-modulation of the $π$-electron hopping integrals. We calculate the phonon spectra of selected antidot lattices using two different semi-empirical methods. Based on the adopted model, we quantify the nature of charge

  18. Joachim Hilgert, Michael Schroeder

    There is a remarkable relation between two kinds of phase space distributions associated to eigenfunctions of the Laplacian of a compact hyperbolic manifold: It was observed in \cite{AZ} that for compact hyperbolic surfaces $X_Γ=Γ\backslash\mathbb{H}$ Wigner distributions $\int_{S^* X_Γ} a dW_{ir_j} = < \mathrm{Op}(a)ϕ_{ir_j},ϕ_{ir_j} >_{L^2(X_Γ)}$ and Patte

  19. Jason Kumar, Louis Leblond, Arvind Rajaraman

    We analyze multi-field inflationary systems which yield strongly scale dependent non-Gaussianity with a shape that is very close to the local shape. As in usual multi-field models, the non-Gaussianity arises from the non-linear transfer of scalar field fluctuations to curvature perturbations. Here we consider models in which higher order terms (loops) domina

  20. K. Gehrke, V. Moshnyaga, O. I. Lebedev, D. Kirilenko

    An interface modification of LCMO-BTO superlattices was found to massively influence magnetic and magnetotransport properties. Moreover it determines the crystal structure of the manganite layers, changing it from orthorhombic (Pnma) for the conventional superlattice (cSL), to rhombohedral (R-3c) for the modified one (mSL). While the cSL shows extremely nonl

  21. V. Capraro

    In this paper we give an algebraic characterization of the projections lattice of $M_n(\mathbb C)$ and we extend it to the case of $B(H)$, with $H$ separable Hilbert space.

  22. Gerson J. Ferreira, Henrique J. P. Freire, J. Carlos Egues

    The longitudinal resistivity $ρ_{xx}$ of two-dimensional electron gases formed in wells with two subbands displays ringlike structures when plotted in a density--magnetic-field diagram, due to the crossings of spin-split Landau levels (LLs) from distinct subbands. Using spin density functional theory and linear response, we investigate the shape and spin pol

  23. Ben Fairbairn

    Let G be a group. We say that G has spread r if for any set of distinct non-trivial elements {x1,...,xr}\subset G there exists an element y\in G with the property that <xi, y> = G for every 1 0<i<r+1. The group G has exact spread r if it has spread r but not r + 1. The case where G is a finite simple group is particularly interesting since it is known that i

  24. M. A. Cirone, G. De Chiara, G. M. Palma, A. Recati

    We examine the time evolution of cold atoms (impurities) interacting with an environment consisting of a degenerate bosonic quantum gas. The impurity atoms differ from the environment atoms, being of a different species. This allows one to superimpose two independent trapping potentials, each being effective only on one atomic kind, while transparent to the

  25. R. Louvot

    The large data sample being recorded with the Belle detector at the Y(5S) energy provides a unique opportunity to study the poorly-known Bs0 meson. Three analyses, using a sample of 23.6 /fb, are presented. We report the first observation of the three dominant exclusive Bs0 decays, Bs0 -> Ds*- pi+, Bs0 -> Ds- rho+ and Bs0 -> Ds*- rho+, the first observation

  26. Kazuharu Bamba, Chao-Qiang Geng, Shinji Tsujikawa

    We show that it is possible to obtain a picture of equilibrium thermodynamics on the apparent horizon in the expanding cosmological background for a wide class of modified gravity theories with the Lagrangian density $f(R, ϕ, X)$, where $R$ is the Ricci scalar and $X$ is the kinetic energy of a scalar field $ϕ$. This comes from a suitable definition of an en

  27. Joshua Robinson, Kathleen Trumbull, Randall Cavalero, Xiaojun Weng

    This paper has been withdrawn due to the adherance to the double submission policies of a refereed journal. Our apologies.

  28. A. Khodjamirian

    I discuss recent applications of QCD light-cone sum rules to various form factors of pseudoscalar mesons. In this approach both soft and hard contributions to the form factors are taken into account. Combining QCD calculation with the analyticity of the form factors, one enlarges the region of accessible momentum transfers.

  29. Shaohua Zhang

    In this note, we generalize an ancient Greek inequality about the sequence of primes to the cases of arithmetic progressions even multivariable polynomials with integral coefficients. We also refine Bouniakowsky&#39;s conjecture [16] and Conjecture 2 in [22]. Moreover, we give two remarks on conjectures in [22]

  30. Jose Natario

    We give an elementary derivation of the Montgomery phase formula for the motion of an Euler top, using only basic facts about the Euler equation and parallel transport on the 2-sphere (whose holonomy is seen to be responsible for the geometric phase). We also give an approximate geometric interpretation of the geometric phase for motions starting close to an

  31. Tommaso Giannantonio, Matteo Martinelli, Alessandra Silvestri, Alessandro Melchiorri

    We study the effects of modified theories of gravity on the cosmic microwave background (CMB) anisotropies power spectrum, and in particular on its large scales, where the integrated Sachs-Wolfe (ISW) effect is important. Starting with a general parametrisation, we then specialise to f(R) theories and theories with Yukawa-type interactions between dark matte

  32. Satoshi Maeda, Shinji Mukohyama, Tetsuya Shiromizu

    The origin of large-scale magnetic field in the universe is one of the greatest mysteries in modern cosmology. We present a new mechanism for generation of large-scale magnetic field, based on the power-counting renormalizable theory of gravitation recently proposed by Horava. Contrary to the usual case in general relativity, the U(1) gauge symmetry of a Max

  33. Hiromitsu Takeuchi, Naoya Suzuki, Kenichi Kasamatsu, Hiroki Saito

    We theoretically study the Kelvin-Helmholtz instability in phase-separated two-component Bose-Einstein condensates using the Gross-Pitaevskii and Bogoliubov-de Gennes models. A flat interface between the two condensates is shown to deform into sawtooth or Stokes-like waves, leading to the formation of singly quantized vortices on the peaks and troughs of the

  34. H. S. Cheon, Sin Kyu Kang, C. S. Kim

    An extended seesaw model proposed to achieve low scale leptogenesis can resolve the excess positron and electron fluxes observed from PAMELA, ATIC and/or Fermi-LAT, and simultaneously accommodate some of recent experimental results for dark matter (DM) signals. In this approach, in addition to SU(2)_L doublet and the (light) singlet Higgs fields, an extra ve

  35. S. Roushon

    Using a recent result of Bartels and Lueck (arXiv:0901.0442) we deduce that the Farrell-Jones Fibered Isomorphism conjecture in L-theory is true for any group which contains a finite index strongly poly-free normal subgroup, in particular, for the Artin full braid groups. As a consequence we explicitly compute the surgery groups of the Artin pure braid group

  36. Tim Roemer, Kirsten Schmitz

    We show that the algebraic invariants multiplicity and depth of a graded ideal in the polynomial ring are closely connected to the fan structure of its generic tropical variety in the constant coefficient case. Generically the multiplicity of the ideal is shown to correspond directly to a natural definition of multiplicity of cones of tropical varieties. Mor

  37. John Whitbeck, Vania Conan, Marcelo Dias de Amorim

    Connectivity patterns in intermittently-connected mobile networks (ICMN) can be modeled as edge-Markovian dynamic graphs. We propose a new model for epidemic propagation on such graphs and calculate a closed-form expression that links the best achievable delivery ratio to common ICMN parameters such as message size, maximum tolerated delay, and link lifetime

  38. Jerome Buzzi, Lorenzo Zambotti

    G. Edelman, O. Sporns, and G. Tononi introduced in theoretical biology the neural complexity of a family of random variables. This functional is a special case of intricacy, i.e., an average of the mutual information of subsystems whose weights have good mathematical properties. Moreover, its maximum value grows at a definite speed with the size of the syste

  39. S. Ejiri, Y. Maezawa, N. Ukita, S. Aoki

    We study the equation of state at finite temperature and density in two-flavor QCD with the RG-improved gluon action and the clover-improved Wilson quark action on a $ 16^3 \times 4$ lattice. Along the lines of constant physics at $m_{\rm PS}/m_{\rm V} = 0.65$ and 0.80, we compute the second and forth derivatives of the grand canonical partition function wit

  40. Herve Guiol, Fabio P. Machado, Rinaldo B. Schinazi

    We propose a stochastic model for evolution. Births and deaths of species occur with constant probabilities. Each new species is associated with a fitness sampled from the uniform distribution on [0,1]. Every time there is a death event then the type that is killed is the one with the smallest fitness. We show that there is a sharp phase transition when the

  41. Vladan Pankovic

    In this work we suggest an original, realistic and simple, form of the experiment of interference of single photon at beam splitter. Here quantum entanglement (Schrodinger cat effect) between photon and photon trajectories detector (which includes two same simple two-level systems) is studied. It admits a consistent model of the detection or measurement proc

  42. Jerome Thiebaut, Simon Prunet, Christophe Pichon, Eric Thiébaut

    We investigate the problem of probing the local spatial structure of the magnetic field of the interstellar medium using multi-frequency polarized maps of the synchrotron emission at radio wavelengths. We focus in this paper on the three-dimensional reconstruction of the largest scales of the magnetic field, relying on the internal depolarization (due to dif

  43. S. R. Hudson, R. L. Dewar

    Two candidates for &#34;almost-invariant&#34; toroidal surfaces passing through magnetic islands, namely quadratic-flux-minimizing (QFMin) surfaces and ghost surfaces, use families of periodic pseudo-orbits (i.e. paths for which the action is not exactly extremal). QFMin pseudo-orbits, which are coordinate-dependent, are field lines obtained from a modified

  44. S. Grap, V. Meden

    We use Wilsons weak coupling ``momentum&#39;&#39; shell renormalization group method to show that two-particle interaction terms commonly neglected in bosonization of one-dimensional correlated electron systems with open boundaries are indeed irrelevant in the renormalization group sense. Our study provides a more solid ground for many investigations of Lutt

  45. Cédric Simenel, Philippe Chomaz

    We study the couplings between collective vibrations such as the isovector giant dipole and isoscalar giant quadrupole resonances in tin isotopes in the framework of the time-dependent Hartree-Fock theory with a Skyrme energy density functional. These couplings are a source of anharmonicity in the multiphonon spectrum. In particular, the residual interaction

  46. J. A. Bergstra, C. A. Middelburg

    Instruction sequences with direct and indirect jump instructions are as expressive as instruction sequences with direct jump instructions only. We show that, in the case where the number of instructions is not bounded, we are faced with increases of the maximal internal delays of instruction sequences on execution that are not bounded by a linear function if

  47. J. A. Bergstra, C. A. Middelburg

    An inversive meadow is a commutative ring with identity equipped with a multiplicative inverse operation made total by choosing 0 as its value at 0. Previously, inversive meadows were shortly called meadows. A divisive meadow is an inversive meadows with the multiplicative inverse operation replaced by a division operation. In the spirit of Peacock&#39;s ari

  48. The BES Collaboration, M. Ablikim

    We report the first observation of $\mPJpsi \to \mPeta\mPKst\mAPKst$ decay in a $\mPJpsi$ sample of 58 million events collected with the BESII detector. The branching fraction is determined to be $(1.15 \pm 0.13 \pm 0.22)\times 10^{-3}$. The selected signal event sample is further used to search for the $\mPY$ resonance through $\mPJpsi \to \mPeta \mPY, \mPY

  49. Fayyazuddin

    Using the unitarity, SU(2) and $C$-invariance of hadronic interactions, the bounds on final state phases are derived. It is shown that values obtained for the final state phases relevant for the direct CP-asymmetries $A_{CP}(B^{0}\to K^{+}π^{-},K^{0}π^{0})$ are compatiable with experimental values for these asymmetries. For the decays $B^{0}\to D^{(\ast)-}π^

  50. Michael E. Tobar, Eugene N. Ivanov, Paul L. Stanwix, Jean-Michel G. le Floch

    We report the first operation of a rotating odd-parity Lorentz Invariance test in electrodynamics using a microwave Mach-Zehnder interferometer with permeable material in one arm. The experiment sets a direct bound to $ κ_{tr}$ of $-0.3\pm 3\times10^{-7}$. Using new power recycled waveguide interferometer techniques (with the highest spectral resolution ever

  51. Pingzhi Yuan

    Let $G$ be a finite abelian group, and let $S$ be a sequence over $G$. Let $f(S)$ denote the number of elements in $G$ which can be expressed as the sum over a nonempty subsequence of $S$. In this paper, we determine all the sequences $S$ that contains no zero-sum subsequences and $f(S)\leq 2|S|-1$.

  52. Kazufumi Torii, Natsuko Kudo, Motosuji Fujishita, Tokuichi Kawase

    Fukui et al. (2006) discovered two molecular loops in the Galactic center and argued that the foot points of the molecular loops, two bright spots at both loops ends, represent the gas accumulated by the falling motion along the loops, subsequent to magnetic flotation by the Parker instability. We have carried out sensitive CO observations of the foot points

  53. Yun Soo Myung

    We investigate a close connection between generalized uncertainty principle (GUP) and deformed Ho\v{r}ava-Lifshitz (HL) gravity. The GUP commutation relations correspond to the UV-quantum theory, while the canonical commutation relations represent the IR-quantum theory. Inspired by this UV/IR quantum mechanics, we obtain the GUP-corrected graviton propagator

  54. V. Sreekanth Annapureddy, Venugopal V. Veeravalli

    Using Gaussian inputs and treating interference as noise at the receivers has recently been shown to be sum capacity achieving for the two-user single-input single-output (SISO) Gaussian interference channel in a low interference regime, where the interference levels are below certain thresholds. In this paper, such a low interference regime is characterized

  55. Pekka Koskela, Dachun Yang, Yuan Zhou

    In this paper, we establish the equivalence between the Hajłasz-Sobolev spaces or classical Triebel-Lizorkin spaces and a class of grand Triebel-Lizorkin spaces on Euclidean spaces and also on metric spaces that are both doubling and reverse doubling. In particular, when $p\in(n/(n+1),\infty)$, we give a new characterization of the Hajłasz-Sobolev spaces $\d

  56. Lisandro Hernández de la Peña, Gilles H. Peslherbe

    This paper has been withdrawn by the authors due to a copyright conflict with the Journal of Physical Chemistry B, to which it has been submitted.

  57. Matthew J. O&#39;Dowd, David Schiminovich, Benjamin D. Johnson, Marie A. Treyer

    We present the analysis of the Polycyclic Aromatic Hydrocarbon (PAH) spectra of a sample of 92 typical star forming galaxies at 0.03 < z < 0.2 observed with the Spitzer IRS. We compare the relative strengths of PAH emission features with SDSS optical diagnostics to probe the relationship between PAH grain properties and star formation and AGN activity. Short

  58. Ian W. Frank, Parag B. Deotare, Murray W. McCutcheon, Marko Loncar

    Wavelength-scale, high Q-factor photonic crystal cavities have emerged as a platform of choice for on-chip manipulation of optical signals, with applications ranging from low-power optical signal processing and cavity quantum electrodynamics, to biochemical sensing. Many of these applications, however, are limited by the fabrication tolerances and the inabil

  59. Sergi Elizalde, Yangyang Liu

    The allowed patterns of a map on a one-dimensional interval are those permutations that are realized by the relative order of the elements in its orbits. The set of allowed patterns is completely determined by the minimal patterns that are not allowed. These are called basic forbidden patterns. In this paper we study basic forbidden patterns of several funct

  60. Sergi Elizalde

    A permutation p is realized by the shift on N symbols if there is an infinite word on an N-letter alphabet whose successive left shifts by one position are lexicographically in the same relative order as p. The set of realized permutations is closed under consecutive pattern containment. Permutations that cannot be realized are called forbidden patterns. It

  61. M. S. Pierce, K. C. Chang, D. Hennessy, V. Komanicky

    We present coherent speckled x-ray diffraction patterns obtained from a monolayer of surface atoms. We measured both the specular anti-Bragg reflection and the off-specular hexagonal reconstruction peak for the Au (0 0 1) surface reconstruction. We observed fluctuations of the speckle patterns even when the integrated intensity appears static. By auto-correl

  62. Donald H. Eckhardt, José Luis G. Pestaña, Ephraim Fischbach

    The van Dam-Veltman-Zakharov (vDVZ) discontinuity requires that the mass $m$ of the graviton is exactly zero, otherwise measurements of the deflection of starlight by the Sun and the precession of Mercury&#39;s perihelion would conflict with their theoretical values. This theoretical discontinuity is open to question for numerous reasons. In this paper we sh

  63. Mario Ponce

    We present an example of a fibred quadratic polynomial admitting an attracting invariant 2-curve. By an unfolding construction we obtain an example of a fibred quadratic polynomial admitting two attracting invariant curves. This phenomena can not occur in the non-fibred setting.

  64. Michaela Kraus, Marcelo Borges Fernandes, Olivier Chesneau

    It is surprising to find dust around B type stars, as in the case of B[e] stars. These stars exhibit a dense, dusty environment witnessed by their infrared-excess and many emission lines from permitted and forbidden transitions. Given the large uncertainties on their distances, this spectral type gathers many different kind of sources that may harbor a simil

  65. A. Fuente, A. Castro-Carrizo, T. Alonso-Albi, M. T. Beltran

    We have carried out high-angular resolution (1.4&#34;) observations in the continuum at 3.1mm and in the N2H+ 1-0, CH3CN 5_k-4_k and 13CS 2-1 lines using the Plateau de Bure Interferometer (PdBI) towards the intermediate mass (IM) protostar IRAS21391+5802 (IC1396N). In addition, we have merged the PdBI images with previous BIMA (continuum data at 1.2mm and 3

  66. Ruy Tojeiro

    We give a complete description of all hypersurfaces of the product spaces $\Sf^n\times \R$ and $\Hy^n\times \R$ that have flat normal bundle when regarded as submanifolds with codimension two of the underlying flat spaces $\R^{n+2}\supset \Sf^n\times \R$ and $\Le^{n+2}\supset \Hy^n\times \R$. We prove that any such hypersurface in $\Sf^n\times \R$ (respectiv

  67. Joseph P. S. Kung

    We give a general multiplication-convolution identity for the multivariate and bivariate rank generating polynomial of a matroid. The bivariate rank generating polynomial is transformable to and from the Tutte polynomial by simple algebraic operations. Several identities, almost all already known in some form, are specializations of this identity. Combinator

  68. J. Shabani, T. Gokmen, Y. T. Chiu, M. Shayegan

    We report the observation of developing fractional quantum Hall states at Landau level filling factors $ν= 1/2$ and 1/4 in electron systems confined to wide GaAs quantum wells with significantly $asymmetric$ charge distributions. The very large electric subband separation and the highly asymmetric charge distribution at which we observe these quantum Hall st

  69. Fernando Manfio, Ruy Tojeiro

    We classify the hypersurfaces of $\Sf^n\times \R$ and $\Hy^n\times \R$ with constant sectional curvature and dimension $n\geq 3$.

  70. Justin R. Crepp, Suvrath Mahadevan, Jian Ge

    High-contrast imaging observations of large angular diameter stars enable complementary science questions to be addressed compared to the baseline goals of proposed missions like the Terrestrial Planet Finder-Coronagraph, New World&#39;s Observer, and others. Such targets however present a practical problem in that finite stellar size results in unwanted sta

  71. A. Finoguenov, J. L. Connelly, L. C. Parker, D. J. Wilman

    X-ray properties of galaxy groups can unlock some of the most challenging research topics in modern extragalactic astronomy: the growth of structure and its influence on galaxy formation. Only with the advent of the Chandra and XMM facilities have X-ray observations reached the depths required to address these questions in a satisfactory manner. Here we pres

  72. D. Saul Davis, Harvey B. Richer, R. Michael Rich, David R. Reitzel

    We present the spectra of 24 white dwarfs in the direction of the globular cluster Messier 4 obtained with the Keck/LRIS and Gemini/GMOS spectrographs. Determining the spectral types of the stars in this sample, we find 24 type DA and 0 type DB (i.e., atmospheres dominated by hydrogen and helium respectively). Assuming the ratio of DA/DB observed in the fiel

  73. Jason S. Kalirai, D. Saul Davis, Harvey B. Richer, P. Bergeron

    Globular star clusters are among the first stellar populations to have formed in the Milky Way, and thus only a small sliver of their initial spectrum of stellar types are still burning hydrogen on the main-sequence today. Almost all of the stars born with more mass than 0.8 M_sun have evolved to form the white dwarf cooling sequence of these systems, and th

  74. Bruno Nachtergaele, Benjamin Schlein, Robert Sims, Shannon Starr

    We construct a W^*-dynamical system describing the dynamics of a class of anharmonic quantum oscillator lattice systems in the thermodynamic limit. Our approach is based on recently proved Lieb-Robinson bounds for such systems on finite lattices.

  75. Salvador A. Sartarelli, Leszek Szybisz

    The adsorption of Ar on substrates of Li is investigated within the framework of a density functional theory which includes an effective pair potential recently proposed. This approach yields good results for the surface tension of the liquid-vapor interface over the entire range of temperatures, T, from the triple point, T_t, to the critical point, T_c. The

  76. Tony Wong

    The timescale for star formation, a measure of how quickly neutral gas is being converted to stars, is considerably longer than typical dynamical timescales associated with a galactic disk. For purposes of modeling galaxy evolution, however, it would be extremely attractive if the star formation timescale were proportional to an easily derived dynamical time

  77. S. R. Doty

    Let G be a semisimple, simply-connected algebraic group over an algebraically closed field of characteristic p > 0. We observe that the tensor product of the Steinberg module with a minuscule module is always indecomposable tilting. Although quite easy to prove, this fact does not seem to have been observed before. It has the following consequence: If p >= 2

  78. Jian Zhou, Feng Yuan, Zuo-Tang Liang

    We study the spin-dependent quark distributions at large transverse momentum. We derive their transverse momentum behaviors in the collinear factorization approach in this region. We further calculate the angular distribution of the Drell-Yan lepton pair production with polarized beams and present the results in terms of the collinear twist-three quark-gluon

  79. J. A. Petrus, P. Bohlouli-Zanjani, J. D. D. Martin

    An oscillating electric field at 1.356 GHz was used to promote the resonant energy transfer process: $43d_{5/2}+43d_{5/2} \to 45p_{3/2}+41f$ between translationally cold $^{85}$Rb Rydberg atoms. The ac Stark shifts due to this dressing field created degeneracies between the initial and final two-atom states of this process. The ac field strength was scanned

  80. T. Toeroek, G. Aulanier, B. Schmieder, K. K. Reeves

    We address the formation of 3D nullpoint topologies in the solar corona by combining Hinode/XRT observations of a small dynamic limb event, which occurred beside a non-erupting prominence cavity, with a 3D zero-beta MHD simulation. To this end, we model the boundary-driven kinematic emergence of a compact, intense, and uniformly twisted flux tube into a pote

  81. Samer Israwi

    We consider here the $1D $ Green-Naghdi equations that are commonly used in coastal oceanography to describe the propagation of large amplitude surface waves. We show that the solution of the Green-Naghdi equations can be constructed by a standard Picard iterative scheme so that there is no loss of regularity of the solution with respect to the initial condi

  82. Aicha Bareche, Ahmed Bouziad

    Let $f: X\times K\to \mathbb R$ be a separately continuous function and $\mathcal C$ a countable collection of subsets of $K$. Following a result of Calbrix and Troallic, there is a residual set of points $x\in X$ such that $f$ is jointly continuous at each point of $\{x\}\times Q$, where $Q$ is the set of $y\in K$ for which the collection $\mathcal C$ inclu

  83. Christopher C. Stark, Marc J. Kuchner

    We present a new &#34;collisional grooming&#34; algorithm that enables us to model images of debris disks where the collision time is less than the Poynting Robertson time for the dominant grain size. Our algorithm uses the output of a collisionless disk simulation to iteratively solve the mass flux equation for the density distribution of a collisional disk

  84. R. T. W. Martin

    Recent results have shown that any closed operator $A$ commuting with the backwards shift $S^*$ restricted to $K ^2_u := H^2 \ominus u H^2$, where $u$ is an inner function, can be realized as a Nevanlinna function of $S^*_u := S^* |_{K^2_u}$, $A = φ(S^*_u)$, where $φ$ belongs to a certain class of Nevanlinna functions which depend on $u$. In this paper this

  85. C. Beck, W. Rammacher

    We investigate the linear correlation coefficient between the intensities at different wavelengths in photospheric and chromospheric spectral lines. Waves that propagate vertically through the stratified solar atmosphere affect different wavelengths at different times. This leads to a characteristic pattern of (non-)coherence of the intensity at various wave

  86. Martin Gorbahn

    We discuss the theory prediction of epsilon_K and the rare K -> pi nu nu-bar decays and review the structure and current status of higher-order contributions to these flavour changing processes in the standard model in some detail. This includes the next-to-next-to-leading order QCD calculation to the charm quark contribution to K+ -> pi+ nu nu-bar and to th

  87. R. T. W. Martin

    Recently it has been shown that any regular simple symmetric operator with deficiency indices (1,1) is unitarily equivalent to the operator of multiplication in a reproducing kernel Hilbert space of functions on the real line with the Kramer sampling property. This work has been motivated, in part, by potential applications to signal processing and mathemati

  88. Bruno Bellomo, Giuseppe Compagno, Hiromichi Nakazato, Kazuya Yuasa

    The dynamics of a system, consisting of a particle initially in a Gaussian state interacting with a field mode, under the action of repeated measurements performed on the particle, is examined. It is shown that regardless of its initial state the field is distilled into a squeezed state. The dependence on the physical parameters of the dynamics is investigat

  89. Anatol N. Kirillov, Vladimir E. Korepin

    A generalized model of Heisenberg quantum antiferromagnet on an arbitrary graph is constructed so that the VBS is the unique ground state. The norm of the base state and equal time multi point correlation functions are computed in terms of generalized hyper geometric functions. For the one-dimensional periodic Heisenberg model we present a method of computin

  90. R. W. Robinett

    We examine the Stark effect (the second-order shift in the energy spectrum due to an external constant force) for two 1-dimensional model quantum mechanical systems described by linear potentials, the so-called quantum bouncer (defined by V(z) = Fz for z>0 and V(z) infinite for z<0) and the symmetric linear potential (given by V(z) = F|z|). We show how strai

  91. Henrique de A. Gomes

    For Riem(M) the space of Riemannian metrics over a compact 3-manifold without boundary $M$, we study topological properties of the dense open subspace Riem&#39;(M) of metrics which possess no Killing vectors. Given the stratification of Riem(M), we work under the condition that, in a sense defined in the text, the connected components of each stratum do not

  92. S. N. Vergeles

    The partition function (quantum transition amplitude) of the gauge system with gauge group $Z_2$ coupled with Majorana fermions is calculated on the regular 3D cubic lattice.

  93. Stan Gudder

    This article begins with a review of quantum measure spaces. Quantum forms and indefinite inner-product spaces are then discussed. The main part of the paper introduces a quantum integral and derives some of its properties. The quantum integral&#39;s form for simple functions is characterized and it is shown that the quantum integral generalizes the Lebesgue

  94. P. Butera, M. Pernici

    The bivariate high-temperature expansion of the spin-spin correlation-function of the three-dimensional classical XY (planar rotator) model, with spatially-anisotropic nearest-neighbor couplings, is extended from the 10th through the 21st order. The computation is carried out for the simple-cubic lattice, in the absence of magnetic field, in the case in whic

  95. James Carlson, Mark Green, Phillip Griffiths

    This paper is a survey of the subject of variations of Hodge structure (VHS) considered as exterior differential systems (EDS). We review developments over the last twenty-six years, with an emphasis on some key examples. In the penultimate section we present some new results on the characteristic cohomology of a homogeneous Pfaffian system. In the last sect

  96. E. Strambini, L. Chirolli, V. Giovannetti, F. Taddei

    We show that an Aharonov-Bohm (AB) ring with asymmetric electron injection can act as a coherent detector of electron dephasing. The presence of a dephasing source in one of the two arms of a moderately-to-highly asymmetric ring changes the response of the system from total reflection to complete transmission while preserving the coherence of the electrons p

  97. Kirill Tuchin

    We derive the total cross section for scattering of a photon on an ultra-short laser pulse at high energies. We take into account all multi-photon interactions. We argue that the nonlinear effects due to these interactions become important at very high intensities of the laser pulse. We demonstrate however, that these intensities are significantly lower than

  98. Dominique Tschopp, Suhas Diggavi

    This paper addresses the problem of finding the nearest neighbor (or one of the R-nearest neighbors) of a query object q in a database of n objects. In contrast with most existing approaches, we can only access the ``hidden&#39;&#39; space in which the objects live through a similarity oracle. The oracle, given two reference objects and a query object, retur

  99. Mark G. Whitney, Nemanja Isailovic, Yatish Patel, John Kubiatowicz

    We optimize the area and latency of Shor&#39;s factoring while simultaneously improving fault tolerance through: (1) balancing the use of ancilla generators, (2) aggressive optimization of error correction, and (3) tuning the core adder circuits. Our custom CAD flow produces detailed layouts of the physical components and utilizes simulation to analyze circu

  100. Santiago J. Barro Torres, Carlos J. Escudero Cascon

    Structure pathology detection is an important security task in building construction, which is performed by an operator by looking manually for damages on the materials. This activity could be dangerous if the structure is hidden or difficult to reach. On the other hand, embedded devices and wireless sensor networks (WSN) are becoming popular and cheap, enab