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November 2008 arXiv papers — page 35

Showing 3,4013,500 of 4,899 papers

  1. Dan Pirjol, Carlos Schat

    We consider the implications of the most general two-body quark-quark interaction Hamiltonian for the spin-flavor structure of the negative parity L=1 excited baryons. Assuming the most general two-body quark interaction Hamiltonian, we derive two correlations among the masses and mixing angles of these states, which constrain the mixing angles, and can be u

  2. Irene Garcia-Selfa, Enrique Gonzalez-Jimenez, Jose M. Tornero

    We find a tight relationship between the torsion subgroup and the image of the mod 2 Galois representation associated to an elliptic curve defined over the rationals. This is shown using some characterizations for the squareness of the discriminant of the elliptic curve.

  3. Etera R. Livine

    In the context of spin foam models for quantum gravity, group field theories are a useful tool allowing on the one hand a non-perturbative formulation of the partition function and on the other hand admitting an interpretation as generalized matrix models. Focusing on 2d group field theories, we review their explicit relation to matrix models and show their

  4. Matías M. Reynoso, Gustavo E. Romero

    We investigate the effects of magnetic fields on neutrino production in microquasars. We calculate the steady particle distributions for the pions and muons generated in p-gamma and p-p interactions in the jet taking the effects of all energy losses into account. The obtained neutrino emission is significantly modified due to the synchrotron losses suffered

  5. P. Blake, R. Yang, S. V. Morozov, F. Schedin

    There is an increasing amount of literature concerning electronic properties of graphene close to the neutrality point. Many experiments continue using the two-probe geometry or invasive contacts or do not control samples' macroscopic homogeneity. We believe that it is helpful to point out some problems related to such measurements. By using experimental

  6. Chris Heunen

    We consider categorical logic on the category of Hilbert spaces. More generally, in fact, any pre-Hilbert category suffices. We characterise closed subobjects, and prove that they form orthomodular lattices. This shows that quantum logic is just an incarnation of categorical logic, enabling us to establish an existential quantifier for quantum logic, and con

  7. Yuji Sano

    The purpose of this paper is to calculate the support of the multiplier ideal sheaves derived from the Kähler-Ricci flow on certain toric Fano manifolds with large symmetry. The early idea of this paper has already been in Appendix of \cite{futaki-sano0711}.

  8. Ilia Musco, John C. Miller, Alexander G. Polnarev

    Following on after two previous papers discussing the formation of primordial black holes in the early universe, we present here results from an in-depth investigation of the extent to which primordial black hole formation in the radiative era can be considered as an example of the critical collapse phenomenon. We focus on initial supra-horizon-scale perturb

  9. Véronique Bruyère, Hadrien Mélot

    The Fibonacci index of a graph is the number of its stable sets. This parameter is widely studied and has applications in chemical graph theory. In this paper, we establish tight upper bounds for the Fibonacci index in terms of the stability number and the order of general graphs and connected graphs. Tur\'an graphs frequently appear in extremal graph theory

  10. Chris Heunen

    We axiomatically define (pre-)Hilbert categories. The axioms resemble those for monoidal Abelian categories with the addition of an involutive functor. We then prove embedding theorems: any locally small pre-Hilbert category whose monoidal unit is a simple generator embeds (weakly) monoidally into the category of pre-Hilbert spaces and adjointable maps, pres

  11. A. Moretti, C. Pagani, G. Cusumano, S. Campana

    We present a new measurement of the cosmic X-ray background (CXRB) in the 1.5-7 keV energy band, performed by exploiting the Swift X-ray telescope (XRT) data archive. We also present a CXRB spectral model in a wider energy band (1.5-200 keV), obtained by combining these data with the recently published Swift-BAT measurement. From the XRT archive we collect a

  12. Kaiichiro Ota, Masaki Nomura, Toshio Aoyagi

    We demonstrate that the phase response curve (PRC) can be reconstructed using a weighted spike-triggered average of an injected fluctuating input. The key idea is to choose the weight to be proportional to the magnitude of the fluctuation of the oscillatory period. Particularly, when a neuron exhibits random switching behavior between two bursting modes, two

  13. Jayeeta Chowdhury, Shreekantha Sil, S. N. Karmakar, Bibhas Bhattacharyya

    We have presented the role of the Coulomb interaction ($U$) and the magnetic field ($\vec{B}$) on the ground state properties of the quasi-one dimensional graphite ribbon structures at half-filling. Mean field Hartree-Fock Approximation is used to study the systems. To understand the boundary effects in graphite structures, we have compared the results of th

  14. Indranath Bhattacharyya

    Generation of neutrino mass in SO(4) model is proposed here. The algebraic structure of SO(4) is same as to that of $SU(2)_{L}\times SU(2)_{R}$. It is shown that the spontaneous symmetry breaking results three massive as well as three massless gauge bosons. The standard model theory according to which there exist three massive gauge bosons and a massless one

  15. Haruka Oguchi, Nobuhiko Taniguchi

    Motivated by recent experiments on electronic transport through a carbon nanotube, we investigate the role of the intra- and inter-orbital Coulomb interactions on the temperature evolution of the conductance. It is shown that small amount (~10%) of asymmetry between these Coulomb repulsions substantially deforms the conductance profile at finite temperature,

  16. Kazuyuki Muraoka, Kotaro Kohno, Tomoka Tosaki, Nario Kuno

    We present aperture synthesis high-resolution (~ 7" x 3") observations in CO(J=1-0) line, HCN(J=1-0) line, and 95 GHz continuum emission toward the central (~ 1.5 kpc) region of the nearby barred spiral galaxy M 83 with the Nobeyama Millimeter Array. Our high-resolution CO(J=1-0) mosaic map depicts the presence of molecular ridges along the leading s

  17. A. V. Minkevich, A. S. Garkun, V. I. Kudin

    Cosmological solutions for homogeneous isotropic models in the framework of the Poincaré gauge theory of gravity based on gravitational Lagrangian adopted in the paper by Kun-Feng Shie, James M. Nester and Hwei-Jang Yo (Phys. Rev. D \textbf{78}, 023522 (2008)) are discussed. Cosmological solutions for accelerating Universe obtained in referred paper are comp

  18. Jörg Pretz, Jean-Marc Le Goff

    This article discusses the determination of asymmetries. We consider a sample of events consisting of a peak of signal events on top of some background events. Both signal and background have an unknown asymmetry, e.g. a spin or forward-backward asymmetry. A method is proposed which determines signal and background asymmetries simultaneously using event weig

  19. J. E. Amaro, E. Hernández, J. Nieves, M. Valverde

    We have developed a model for neutrino-induced coherent pion production off nuclei in the energy regime of interest for present and forthcoming neutrino oscillation experiments. It is based on a microscopic model for pion production off the nucleon that, besides the dominant Delta pole contribution, takes into account the effect of background terms required

  20. Hua Zhang

    For $n\geq 2$, we establish the smooth effects for the solutions of the linear fourth order Shrödinger equation in anisotropic Lebesgue spaces with $\Box_k$-decomposition. Using these estimates, we study the Cauchy problem for the fourth order nonlinear Schrödinger equations with three order derivatives and obtain the global well posedness for this problem w

  21. Pokman Cheung

    This article is the first report of an ongoing project aimed at finding a geometric interpretation of the Witten genus and other tmf classes. Section 2 reviews the sheaves of chiral differential operators (CDOs) over a complex manifold, including their construction, obstructions and relation with the Witten genus. In section 3, the structure of each sheaf of

  22. S. Alekhin, S. Moch

    We study the perturbative QCD corrections to heavy-quark structure functions of charged-lepton deep-inelastic scattering and their impact on global fits of parton distributions. We include the logarithmically enhanced terms near threshold due to soft gluon resummation in the QCD corrections at next-to-next-to-leading order. We demonstrate that this approxima

  23. Kyle R. Stewart, James S. Bullock, Elizabeth J. Barton, Risa H. Wechsler

    We employ a high-resolution LCDM N-body simulation to present merger rate predictions for dark matter halos and investigate how common merger-related observables for galaxies--such as close pair counts, starburst counts, and the morphologically disturbed fraction--likely scale with luminosity, stellar mass, merger mass ratio, and redshift from z=0 to z=4. We

  24. Nadir Matringe

    Let $K/F$ be a quadratic extension of p-adic fields. The Bernstein-Zelevinsky's classification asserts that generic representations are parabolically induced from quasi-square-integrable representations. We show, following a method developed by Cogdell and Piatetski-Shapiro, that the equality of the Rankin-Selberg type Asai $L$-function of generic repres

  25. Inga Kuznetsova, Johann Rafelski

    We investigate the yield of $Λ(1520)$ resonance in heavy ion collisions within the framework of a kinetic master equation without the assumption of chemical equilibrium. We show that reactions such as $Λ(1520)+π\leftrightarrow Σ^*$ can favor $Σ^*$ production, thereby decreasing the $Λ(1520)$ yield. Within the same approach we thus find a yield enhancement fo

  26. Congjun Wu, Daniel Arovas, Hsiang-Hsuan Hung

    We extend the Kitaev model defined for the Pauli-matrices to the Clifford algebra of $Γ$-matrices, taking the $4 \times 4$ representation as an example. On a decorated square lattice, the ground state spontaneously breaks time-reversal symmetry and exhibits a topological phase transition. The topologically non-trivial phase carries gapless chiral edge modes

  27. Shoichi Sasaki, Takeshi Yamazaki

    We present a quenched lattice calculation of all six form factors: vector [f_1(q^2)], weak magnetism [f_2(q^2)], induced scalar [f_3(q^2)], axial-vector [g_1(q^2)], weak electricity [g_2(q^2)] and induce pseudoscalar [g_3(q^2)] form factors in hyperon semileptonic decay Xi^0 -> Sigma^{+} l nu using domain wall fermions. The q^2 dependences of all form factor

  28. James Guillochon, Enrico Ramirez-Ruiz, Stephan Rosswog, Daniel Kasen

    We describe a three-dimensional simulation of a $1 M_{\odot}$ solar-type star approaching a $10^{6} M_{\odot}$ black hole on a parabolic orbit with a pericenter distance well within the tidal radius. While falling towards the black hole, the star is not only stretched along the orbital direction but even more severely compressed at right angles to the orbit.

  29. Marcius H. T. Extavour, Lindsay J. LeBlanc, Jason McKeever, Alma B. Bardon

    We review our recent and ongoing work with Fermi gases on an atom chip. After reviewing some statistical and thermodynamic properties of the ideal, non-interacting Fermi gas, and a brief description of our atom chip and its capabilities, we discuss our experimental approach to producing a potassium-40 degenerate Fermi gas (DFG) using sympathetic cooling by a

  30. Joel Foisy, Jared Federman, Kristin McNamara, Emily Stark

    Flapan--Naimi--Pommersheim showed that every spatial embedding of $K_{10}$, the complete graph on ten vertices, contains a non-split three-component link; that is, $K_{10}$ is intrinsically triple-linked in $\mathbb{R}^3$. The work of Bowlin--Foisy and Flapan--Foisy--Naimi--Pommersheim extended the list of known intrinsically triple-linked graphs in $\mathbb

  31. Kate Brand, John Moustakas, Lee Armus, Roberto J. Assef

    Observations with the Spitzer Space Telescope have revealed a population of red-sequence galaxies with a significant excess in their 24-micron emission compared to what is expected from an old stellar population. We identify 900 red galaxies with 0.15<z<0.3 from the AGN and Galaxy Evolution Survey (AGES) selected from the NOAO Deep Wide-Field Survey Bootes f

  32. Dario Benedetti

    We show that in general a spacetime having a quantum group symmetry has also a scale dependent fractal dimension which deviates from its classical value at short scales, a phenomenon that resembles what observed in some approaches to quantum gravity. In particular we analyze the cases of a quantum sphere and of $\k$-Minkowski, the latter being relevant in th

  33. L. A. Tracy, E. H. Hwang, K. Eng, G. A. Ten Eyck

    By analyzing the temperature ($T$) and density ($n$) dependence of the measured conductivity ($σ$) of 2D electrons in the low density ($\sim10^{11}$cm$^{-2}$) and temperature (0.02 - 10 K) regime of high-mobility (1.0 and 1.5 $\times 10^4$ cm$^2$/Vs) Si MOSFETs, we establish that the putative 2D metal-insulator transition is a density-inhomogeneity driven pe

  34. Igor V. Dolgachev

    We show that the plane Cremona group over a field of characteristic p > 0 does not contain elements of order of power of p larger than 2 and it does not contain elements of order p^2 unless p =2. Also we describe conjugacy classes of elements of order 4.

  35. Brent C. Melot, Katharine Page, Ram Seshadri, E. M. Stoudenmire

    The spinels CoB$_2$O$_4$ with magnetic Co$^{2+}$ ions on the diamond lattice A site can be frustrated because of competing near-neighbor ($J_1$) and next-near neighbor ($J_2$) interactions. Here we describe attempts to tune the relative strengths of these interactions by substitution on the non-magnetic B-site. The system we employ is CoAl$_{2-x}$Ga$_x$O$_4$

  36. Ghislain Fourier, Masato Okado, Anne Schilling

    For nonexceptional types, we prove a conjecture of Hatayama et al. about the prefectness of Kirillov-Reshetikhin crystals.

  37. Andrea Nerozzi, Oliver Elbracht

    We present a new expression for the Weyl scalar Psi_4 that can be used in numerical relativity to extract the gravitational wave content of a spacetime. The formula relies upon the identification of transverse tetrads, namely the ones in which Psi_1=Psi_3=0. It is well known that tetrads with this property always exist in a general Petrov type I spacetime. A

  38. T. Emig, N. Graham, R. L. Jaffe, M. Kardar

    The Casimir interaction between two objects, or between an object and a plane, depends on their relative orientations. We make these angular dependences explicit by considering prolate or oblate spheroids. The variation with orientation is calculated exactly at asymptotically large distances for the electromagnetic field, and at arbitrary separations for a s

  39. Jen-Tsung Hsiang, L. H. Ford

    We discuss the various manifestations of quantum decoherence in the forms of dephasing, entanglement with the environment, and revelation of &#34;which-path&#34; information. As a specific example, we consider an electron interference experiment. The coupling of the coherent electrons to the quantized electromagnetic field illustrates all of these versions o

  40. F. Calura, M. Dessauges-Zavadsky, J. X. Prochaska, F. Matteucci

    Long-duration Gamma Ray Bursts (GRBs) are linked to the collapse of massive stars and their hosts are exclusively identified as active, star forming galaxies. Four long GRBs observed at high spectral resolution at redshift 1.5 <z < 4 allowed the determination of the elemental abundances for a set of different chemical elements. In this paper, for the first t

  41. G. Mennessier

    We estimate the I=0 scalar meson $σ/f_0(600)$ $γγ$ widths, from $ππ$ and $γγ$ scattering data below 700 MeV using an improved analytic K-matrix model.

  42. W. D. Wise, Kamalesh Chatterjee, M. C. Boyer, Takeshi Kondo

    Particle-wave duality suggests we think of electrons as waves stretched across a sample, with wavevector k proportional to their momentum. Their arrangement in &#34;k-space,&#34; and in particular the shape of the Fermi surface, where the highest energy electrons of the system reside, determine many material properties. Here we use a novel extension of Fouri

  43. Niayesh Afshordi, Roya Mohayaee, Edmund Bertschinger

    Most of the mass content of dark matter haloes is expected to be in the form of tidal debris. The density of debris is not constant, but rather can grow due to formation of caustics at the apocenters and pericenters of the orbit, or decay as a result of phase mixing. In the phase space, the debris assemble in a hierarchy which is truncated by the primordial

  44. Amelia M. Stutz, Tyler L. Bourke, George H. Rieke, John H. Bieging

    We present Spitzer infrared observations of the starless core L429. The IR images of this core show an absorption feature, caused by the dense core material, at wavelengths <= 70 micron. The core has a steep density profile, and reaches A_V > 35 mag near the center. We show that L429 is either collapsing or in a near-collapse state.

  45. P. P. Avelino, R. Menezes, L. Sousa

    We study the evolution of maximally symmetric $p$-branes with a $S_{p-i}\otimes \mathbbm{R}^i$ topology in flat expanding or collapsing homogeneous and isotropic universes with $N+1$ dimensions (with $N \ge 3$, $p < N$, $0 \le i < p$). We find the corresponding equations of motion and compute new analytical solutions for the trajectories in phase space. For

  46. C. Firmani, J. I. Cabrera, V. Avila-Reese, G. Ghisellini

    For a sample of long GRBs with known redshift, we study the distribution of the evolutionary tracks on the rest-frame luminosity-peak energy Liso-Ep&#39; diagram. We are interested in exploring the extension of the `Yonetoku&#39; correlation to any phase of the prompt light curve, and in verifying how the high-signal prompt duration time, Tf, in the rest fra

  47. Kurtis A. Williams, Michael Bolte, Detlev Koester

    We present a photometric and spectroscopic study of the white dwarf population of the populous, intermediate-age open cluster M35 (NGC 2168); this study expands upon our previous study of the white dwarfs in this cluster. We spectroscopically confirm 14 white dwarfs in the field of the cluster: 12 DAs, 1 hot DQ, and 1 DB star. For each DA, we determine the w

  48. J. Gerssen, D. J. Wilman, L. Christensen, R. G. Bower

    We have used the VIMOS IFU to map the properties of the Seyfert 1.9 galaxy LEDA 135736. These maps reveal a number of interesting features including: an Extended Narrow Line Region detectable out to 9 kpc, an area of intense star formation located at a projected distance of 12 kpc from the centre, an elliptical companion galaxy, and kinematic features, align

  49. Takuya Yoshioka, Akihisa Koga, Norio Kawakami

    We investigate the quantum phase transitions in the half-filled Hubbard model on the triangular lattice by means of the path-integral renormalization group (PIRG) method with a new iteration scheme proposed recently. It is found that as the Hubbard interaction $U$ increases, the paramagnetic metallic state undergoes a first-order phase transition to a nonmag

  50. Stuart Margolis, Benjamin Steinberg

    We develop the homology theory of the algebra of a regular semigroup, which is a particularly nice case of a quasi-hereditary algebra in good characteristic. Directedness is characterized for these algebras, generalizing the case of semisimple algebras studied by Munn and Ponizovksy. We then apply homological methods to compute (modulo group theory) the quiv

  51. Ivan G. Avramidi, Guglielmo Fucci

    In a previous work we showed that massive test particles exhibit a non-geodesic acceleration in a modified theory of gravity obtained by a non-commutative deformation of General Relativity (so-called Matrix Gravity). We propose that this non-geodesic acceleration might be the origin of the anomalous acceleration experienced by the Pioneer 10 and Pioneer 11 s

  52. Martin Bojowald, Golam Mortuza Hossain, Mikhail Kagan, S. Shankaranarayanan

    A consistent implementation of quantum gravity is expected to change the familiar notions of space, time and the propagation of matter in drastic ways. This will have consequences on very small scales, but also gives rise to correction terms in evolution equations of modes relevant for observations. In particular, the evolution of inhomogeneities in the very

  53. Salah A. Aly, Andreas Klappenecker

    Subsystem codes protect quantum information by encoding it in a tensor factor of a subspace of the physical state space. Subsystem codes generalize all major quantum error protection schemes, and therefore are especially versatile. This paper introduces numerous constructions of subsystem codes. It is shown how one can derive subsystem codes from classical c

  54. P-L. Buono, M. Helmer, J. S. W. Lamb

    Let $G$ be a finite group acting on vector spaces $V$ and $W$ and consider a smooth $G$-equivariant mapping $f:V\to W$. This paper addresses the question of the zero set near a zero $x$ of $f$ with isotropy subgroup $G$. It is known from results of Bierstone and Field on $G$-transversality theory that the zero set in a neighborhood of $x$ is a stratified set

  55. J. H. Bauer

    Some results from a recent work of Reiss [Phys. Rev. Lett. 101, 043002 (2008); 101, 159901(E) (2008).] are generalized for the case of elliptical polarization of a laser field. We also discuss the tunneling limit of strong-field photoionization.

  56. H. W. W. Spoon, L. Armus, J. A. Marshall, J. Bernard-Salas

    We report the first mid-IR detection of highly disturbed ionized gas in the ultraluminous infrared galaxy IRAS F00183-7111. The gas, traced by the 12.81um [NeII] and 15.56um [NeIII] lines, spans a velocity range of-3500 to 3000 km/s with respect to systemic velocity. Optical and near-IR spectroscopic studies show no evidence for similarly high velocity gas c

  57. J. L. Hinz, G. H. Rieke, F. Yusef-Zadeh, J. Hewitt

    We present a 1.5deg x 8deg (220pc x 1195pc) Multiband Imaging Photometer for Spitzer 24um image of the Galactic Center and an accompanying point source list. This image is the highest spatial resolution (6&#34; ~ 0.25pc) and sensitivity map ever taken across the GC at this wavelength, showing the emission by warm dust in unprecedented detail. Over 120,000 po

  58. Alejandro Ibarra, David Tran

    Astrophysical and cosmological observations do not require the dark matter particles to be absolutely stable. If they are indeed unstable, their decay into positrons might occur at a sufficiently large rate to allow the indirect detection of dark matter through an anomalous contribution to the cosmic positron flux. In this paper we discuss the implications o

  59. M. J. Disney, J. D. Romano, D. A. Garcia-Appadoo, A. A. West

    Galaxies are complex systems the evolution of which apparently results from the interplay of dynamics, star formation, chemical enrichment, and feedback from supernova explosions and supermassive black holes. The hierarchical theory of galaxy formation holds that galaxies are assembled from smaller pieces, through numerous mergers of cold dark matter. The pr

  60. Sivan Leviyang

    We examine genetic statistics used in the study of structured populations. In a 1999 paper, Wakeley observed that the coalescent process associated with the finite island model can be decomposed into a scattering phase and a collecting phase. In this paper, we introduce a class of population structure models, which we refer to as G/KC models, that obey such

  61. Jonathan Needleman

    In this paper we give a complete invariant of the action of GL_n(F)\times GL_m(F) acting on the Euclidean building B[GL_n(F)], where F is a non-archimedian field. We then use this invariant to give a natural metric on the resulting quotient space. In the special case of the torus acting on B[GL_2(F)] this gives a method of calculating of any vertex to any fi

  62. Igor Rochev

    We prove a result on linear forms related to Peres-Schlag&#39;s theorem on badly approximable numbers with respect to lacunary sequences.

  63. Colin Wilmott, Peter Wild

    The qubit SWAP gate has been shown to be an integral component of quantum circuitry design. It permutes the states of two qubits and allows for the storage quantum information, teleportation of atomic or ionic states, and is a fundamental element in the circuit implementation of Shor&#39;s algorithm. We consider the problem of generalising the SWAP gate beyo

  64. C. Royon

    In this short report, we discuss the Jet Physics results and perspectives at HERA, Tevatron and LHC.

  65. S. Felsner, K. Knauer

    A D-polyhedron is a polyhedron $P$ such that if $x,y$ are in $P$ then so are their componentwise max and min. In other words, the point set of a D-polyhedron forms a distributive lattice with the dominance order. We provide a full characterization of the bounding hyperplanes of D-polyhedra. Aside from being a nice combination of geometric and order theoretic

  66. Ulf Gran, George Papadopoulos

    We outline the solution of the Killing spinor equations of the heterotic supergravity. In addition, we describe the classification of all half supersymmetric solutions.

  67. Alireza Rahmati, Mir Abbas Jalali

    We use the weighted integral form of spherical Bessel functions, and introduce a new analytical set of complete and biorthogonal potential--density basis functions. The potential and density functions of the new set have finite central values and they fall off, respectively, similar to $r^{-(1+l)}$ and $r^{-(4+l)}$ at large radii where $l$ is the latitudinal

  68. Bernhard U. Musch, Philipp Hägler, Andreas Schäfer, Dru B. Renner

    Transverse momentum dependent parton distribution functions (TMDPDFs) encode information about the intrinsic motion of quarks inside the nucleon. They are important non-perturbative ingredients in our understanding of, e.g., azimuthal asymmetries and other qualitative features in semi-inclusive deep inelastic scattering experiments. We present first calculat

  69. Daniel W. Weedman, James R. Houck

    The mid-infrared spectroscopic analysis of a flux-limited sample of galaxies with fv(24um) > 10 mJy is presented. Sources observed are taken from the Spitzer First Look Survey (FLS) catalog and from the NOAO Deep Wide-Field Survey region in Bootes (NDWFS). The spectroscopic sample includes 60 of the 100 sources in these combined catalogs having fv(24um) > 10

  70. M. Eckart, R. Walser, W. P. Schleich, S. Zöllner

    We examine ground state correlations for repulsive, quasi one-dimensional bosons in a harmonic trap. In particular, we focus on the few particle limit N=2,3,4,..., where exact numerical solutions of the many particle Schroedinger equation are available employing the Multi-Configuration Time-dependent Hartree method. Our numerical results for the inhomogeneou

  71. D. Pogosyan, C. Pichon, C. Gay, S. Prunet

    The local theory of the critical lines of 2D and 3D Gaussian fields that underline the cosmic structures is presented. In the context of cosmological matter distribution the subset of critical lines of the 3D density field serves to delineate the skeleton of the observed filamentary structure at large scales. A stiff approximation used to quantitatively desc

  72. B. Alles, A. Papa

    The Haldane conjecture, when applied to the Heisenberg O(3) model with a θterm in two dimensions, states that the correlation length ξdiverges when θapproaches π. To verify this conjecture we have numerically simulated the model at imaginary θand then analytically continued the results to real θ. We have obtained that the value where the model should become

  73. Milovan Suvakov, Bosiljka Tadic

    Using numerical modeling we study emergence of structure and structure-related nonlinear conduction properties in the self-assembled nanoparticle films. Particularly, we show how different nanoparticle networks emerge within assembly processes with molecular bio-recognition binding. We then simulate the charge transport under voltage bias via single-electron

  74. Ina Voigt

    It is well known that all cells of the Voronoi diagram of a Delaunay set are polytopes. For a finite point set, all these cells are still polyhedra. So the question arises, if this observation holds for all discrete point sets: Are always all Voronoi cells of an arbitrary, infinite discrete point set polyhedral? In this paper, an answer to this question will

  75. John Murray

    Let B be a real 2-block of a finite group G. Then B has a real defect class. Let g be an element of such a class. A defect couple of B is (D,E), where E is a Sylow 2-subgroup of the extended centralizer C^*(g) of g, and D is the intersection of E with the centralizer C(g). It is known that (D,E) is uniquely determined up to G-conjugacy. We show that (D,E) de

  76. Hans Vernaeve

    We define the algebra of Colombeau generalized functions on a subset A of the space of d-dimensional generalized points. If the domain A is open, such generalized functions can be identified with pointwise maps from A into the ring of Colombeau generalized numbers. We study analyticity in these algebras, if the domain is an open subset of the complex general

  77. Tad Hogg

    Nanotechnology-based microscopic robots could provide accurate in vivo measurement of chemicals in the bloodstream for detailed biological research and as an aid to medical treatment. Quantitative performance estimates of such devices require models of how chemicals in the blood diffuse to the devices. This paper models microscopic robots and red blood cells

  78. Wen-Po Liu, Zhi-Qiang Shen

    We present a modified stratified jet model to interpret the observed spectral energy distributions of knots in 3C 273 jet. Based on the hypothesis of the single index of the particle energy spectrum at injection and identical emission processes among all the knots, the observed difference of spectral shape among different 3C273 knots can be understood as a m

  79. M. Dan, S. Rosswog, M. Brüggen

    We present a numerical study of the mass transfer dynamics prior to the gravitational wave-driven merger of a double white dwarf system. Recently, there has been some discussion about the dynamics of these last stages, different methods seemed to provide qualitatively different results. While earlier SPH simulations indicated a very quick disruption of the b

  80. Pietro De Poi, Emilia Mezzetti, José Carlos Sierra

    A well-known conjecture asserts that smooth threefolds $X\subset\{\mathbb P}^5$ are quadratically normal with the only exception of the Palatini scroll. As a corollary of a more general statement we obtain the following result, which is related to the previous conjecture: If $X\subset\{\mathbb P}^5$ is not quadratically normal, then its triple curve is reduc

  81. Hua-Xing Chen, Atsushi Hosaka, Shi-Lin Zhu

    We study the light scalar mesons in the QCD sum rule. We construct both the diquark-antidiquark currents $(qq)(\bar q \bar q)$ and the meson-meson currents $(\bar qq)(\bar qq)$. We find that there are five independent currents for both cases, and derive the relations between them. For the meson-meson currents, five independent currents are formed by products

  82. Sudhakar Sahoo, Pabitra Pal Choudhury

    This paper proposes several algorithms and their Cellular Automata Machine (CAM) for drawing the State Transition Diagram (STD) of an arbitrary Cellular Automata (CA) Rule (any neighborhood, uniform/ hybrid and null/ periodic boundary) and length of the CA n. It also discusses the novelty, hardware cost and the complexities of these algorithms.

  83. Vlasios Vasileiou

    Milagro is a water-Cherenkov detector that observes the extended air showers produced by cosmic gamma rays of energies E>100GeV. The effective area of Milagro peaks at energies E~10TeV, however it is still large even down to a few hundred GeV (~10m^2 at 100GeV). The wide field of view (~2sr) and high duty cycle (>90%) of Milagro make it ideal for continuousl

  84. A. S. Rodrigues, P. G. Kevrekidis, R. Carretero-González, D. J. Frantzeskakis

    We study the flow of a spinor (F=1) Bose-Einstein condensate in the presence of an obstacle. We consider the cases of ferromagnetic and polar spin-dependent interactions and find that the system demonstrates two speeds of sound that are identified analytically. Numerical simulations reveal the nucleation of macroscopic nonlinear structures, such as dark soli

  85. Rikiya Yoshida, Takanori Wakita, Hiroyuki Okazaki, Yoshikazu Mizuguchi

    We have performed soft x-ray and ultrahigh-resolution laser-excited photoemission measurements on tetragonal FeSe, which was recently identified as a superconductor. Energy dependent study of valence band is compared to band structure calculations and yields a reasonable assignment of partial densities of states. However, the sharp peak near the Fermi level

  86. Guy Pelletier, Martin Lemoine, A. Marcowith

    After a successful development of theoretical and numerical works on Fermi acceleration at relativistic shocks, some difficulties recently raised with the scattering issue, a crucial aspect of the process. Most pioneering works were developed assuming the scattering off magnetic fluctuations as given. Even in that case, when a mean field is considered, its o

  87. R. Nuriyev

    Analysis of asset liability management (ALM) strategies especially for long term horizon is a crucial issue for banks, funds and insurance companies. Modern economic models, investment strategies and optimization criteria make ALM studies computationally very intensive task. It attracts attention to multiprocessor system and especially to the cheapest one: m

  88. Kostyantyn Ilyenko

    For osp(1|2;C) graded Lie algebra, which proper Lie subalgebra is su(2), we consider the Baker-Campbell-Hausdorff formula and formulate a reality condition for the Grassmann-odd transformation parameters that multiply the pair of odd generators of the graded Lie algebra. Utilization of su(2)-spinors clarifies the nature of Grassmann-odd transformation parame

  89. Donna C. Arnold, Kevin S. Knight, Finlay D. Morrison, Philip Lightfoot

    A detailed investigation using variable temperature powder neutron diffraction demonstrates that BiFeO3 undergoes a phase transition from the ferroelectric alpha phase (rhombohedral, R3c) to a paraelectric beta phase (orthorhombic, Pbnm) between 820 oC and 830 oC. Co-existence of both phases over a finite temperature interval, together with abrupt changes in

  90. S Lo, A V Korol, A V Solov&#39;yov

    The present work is a generalisation of the dynamical screening factor presented in [1] to consider an atom located at an arbitrary position within the fullerene. A more elaborated investigation into the case where the atom is located at the centre is performed and compared with quantum mechanical calculations for dynamical screening factor of Ar@C$_{60}$ [2

  91. A. A. Nucita, S. Carpano, F. De Paolis, G. Ingrosso

    The binaries known as cataclysmic variables are particular binary systems in which the primary star (a white dwarf) accretes material from a secondary via Roche-lobe mechanism. Usually, these objects have orbital period of a few hours so that a detailed temporal analysis can be performed. Here, we present Chandra ${\it XMM}$-Newton observations of a dwarf no

  92. Antonella Perucca

    Let G be the product of an abelian variety and a torus defined over a number field K. Let R be a point in G(K) and let L be a finitely generated subgroup of G(K). Suppose that for all but finitely many primes p of K the point (R mod p) belongs to (L mod p). Does it follow that R belongs to L? We answer this question affirmatively in three cases: if L is cycl

  93. Jeroen Homan, David L. Kaplan, Maureen van den Berg, Andrew J. Young

    We report the discovery of a near-infrared (nIR) counterpart to the persistent neutron-star low-mass X-ray binary 4U 1705-440, at a location consistent with its recently determined Chandra X-ray position. The nIR source is highly variable, with K_s-band magnitudes varying between 15.2 and 17.3 and additional J- and H-band observations revealing color variati

  94. Claus Zahlten, Andres Hernandez, Michael G. Schmidt

    The dynamics of weakly coupled, non-abelian gauge fields at high temperature is non-perturbative if the characteristic momentum scale is of order |k|~ g^2 T. Such a situation is typical for the processes of electroweak baryon number violation in the early Universe. Bodeker has derived an effective theory that describes the dynamics of the soft field modes by

  95. Philippe Biane

    We give a geometric description of the motion of eigenvalues of a Brownian motion with values in some matrix spaces. In the second part we consider a paper by Polya where he introduced a function close to the Riemann zeta function, which satisfies Riemann hypothesis. We show that each of these two functions can be related to Brownian motion on a symmetric sp

  96. G. F. Chen, Z. G. Chen, J. Dong, W. Z. Hu

    We report on a comprehensive study of the transport, specific heat, magnetic susceptibility and optical spectroscopy on single crystal of Fe$_{1.05}$Te. We confirm that Fe$_{1.05}$Te undergoes a first-order phase transition near 65 K. However, its physical properties are considerably different from other parent compounds of FeAs-based systems, presumably att

  97. N. W. Evans, J. An, M. G. Walker

    We consider the problem of determining the structure of the dark halo of nearby dwarf spheroidal galaxies (dSphs) from the spherical Jeans equations. Whether the dark halos are cusped or cored at the centre is an important strategic problem in modern astronomy. The observational data comprise the line-of-sight velocity dispersion of a luminous tracer populat

  98. N. Olivi-Tran, A. Ferchichi, S. Calas, P. Etienne

    We computed by a modified tight binding approximation, the total electronic energy of three different hybrid polymers: $H-SiO_2$, $CH_3-SiO_2$ and $C_6H_5-SiO_2$. We made the hypothesis that the structures of these polymers are amorphous. Computational results regarding the total electronic energy and experimental data \cite{ferchichi} on the toughness of th

  99. Boris L. Altshuler

    Spectra of Kaluza-Klein gauge fields are calculated at the background of the magnetic fluxbrane throat-like solution of the Type IIA supergravity equations. Magnetic flux plays the role of Higgs scalar generating the electroweak scale mass of non-abelian KK gauge field. The same &#34;flux-Higgs&#34; mechanism gives the scale of the &#34;second mass hierarchy

  100. Benoit Stroh

    We construct the minimal compactification of some modular Siegel varieties at their bad reduction places. These varieties parametrize principally polarized abelian schemes endowed with a parahoric level structure at a prime number $p$, and with an auxiliary level structure ; such varieties have bad reduction at $p$. We also sketch the arithmetic theory of th