Skip to content

June 2007 arXiv papers — page 39

Showing 3,801–3,900 of 4,521 papers

  1. Jessica M. Conway, Hermann Riecke

    We study the excitation of spatial patterns by resonant, multi-frequency forcing in systems undergoing a Hopf bifurcation to spatially homogeneous oscillations. Using weakly nonlinear analysis we show that for small amplitudes only stripe or hexagon patterns are linearly stable, whereas square patterns and patterns involving more than three modes are unstabl

  2. Erin J. D. Jolley, Zdenka Kuncic

    We explore an accretion model for low luminosity AGN (LLAGN) that attributes the low radiative output to a low mass accretion rate rather than a low radiative efficiency. In this model, electrons are assumed to drain energy from the ions as a result of collisionless plasma microinstabilities. Consequently, the accreting gas collapses to form a geometrically

  3. Spyros Konitopoulos, George Savvidy

    In the recently proposed extension of the YM theory, non-Abelian tensor gauge field of the second rank is represented by a general tensor whose symmetric part describes the propagation of charged gauge boson of helicity two and its antisymmetric part - the helicity zero charged gauge boson. On the non-interacting level these polarizations are similar to the

  4. T. Sato, T. Ishiyama, T. Nikuni

    We study the vortex pinning effect in a Bose-Einstein Condensate in the presence of a rotating lattice potential by numerically solving the time-dependent Gross-Pitaevskii equation. We consider a triangular lattice potential created by blue-detuned laser beams. By rotating the lattice potential, we observe a transition from the Abrikosov vortex lattice to th

  5. Bin Cheng, Eitan Tadmor

    We study the stabilizing effect of rotational forcing in the nonlinear setting of two-dimensional shallow-water and more general models of compressible Euler equations. In [H. Liu and E. Tadmor, Phys. D 188 (2004), no. 3-4, 262-276] we have shown that the pressureless version of these equations admit global smooth solution for a large set of sub-critical ini

  6. Mohammad Hafezi, Anders S. Sorensen, Eugene Demler, Mikhail D. Lukin

    We analyze a recently proposed method to create fractional quantum Hall (FQH) states of atoms confined in optical lattices [A. Sørensen {\it et al.}, Phys. Rev. Lett. {\bf 94} 086803 (2005)]. Extending the previous work, we investigate conditions under which the FQH effect can be achieved for bosons on a lattice with an effective magnetic field and finite on

  7. Feng Dai, Yuan Xu

    For the weight function $\prod_{i=1}^{d+1}|x_i|^{2\k_i}$ on the unit sphere, sharp local estimates of the orthogonal projection operators are obtained and used to prove the convergence of the Cesàro $(C,δ)$ means in the weighted $L^p$ space for $δ$ below the critical index. Similar results are also proved for corresponding weight functions on the unit ball a

  8. Patrick Morrissey, Tim Conrow, Tom A. Barlow, Todd Small

    We describe the calibration status and data products pertaining to the GR2 and GR3 data releases of the Galaxy Evolution Explorer (GALEX). These releases have identical pipeline calibrations that are significantly improved over the GR1 data release. GALEX continues to survey the sky in the Far Ultraviolet (FUV, ~154 nm) and Near Ultraviolet (NUV, ~232 nm) ba

  9. A. A. Taskin, Yoichi Ando

    The magnetic properties of GdBaMn_{2}O_{5.0}, which exhibits charge ordering, are studied from 2 to 400 K using single crystals. In a small magnetic field applied along the easy axis, the magnetization M shows a temperature-induced reversal which is sometimes found in ferrimagnets. In a large magnetic field, on the other hand, a sharp change in the slope of

  10. Thomas Quella, Volker Schomerus

    Extending our earlier work on PSL(2|2), we explain how to reduce the solution of WZNW models on general type I supergroups to those defined on the bosonic subgroup. The new analysis covers in particular the supergroups GL(M|N) along with several close relatives such as PSL(N|N), certain Poincare supergroups and the series OSP(2|2N). This remarkable progress

  11. V. R. Shaginyan, K. G. Popov, V. A. Stephanovich

    The heavy-fermion metal CePd_{1-x}Rh_x evolves from ferromagnetism at x=0 to a non-magnetic state at some critical concentration x_c. Utilizing the quasiparticle picture and the concept of fermion condensation quantum phase transition (FCQPT), we address the question about non-Fermi liquid (NFL) behavior of ferromagnet CePd_{1-x}Rh_x and show that it coincid

  12. Lawrence P. Roberts

    Let L be a link in an thickened annulus. We specify the embedding of this annulus in the three sphere, and consider its complement thought of as the axis to L. In the right circumstances this axis lifts to a null-homologous knot in the double branched cover of the three sphere, branched over the embedded copy of L. This paper shows that the knot Floer homolo

  13. S. Casassus, L. -A. Nyman, C. Dickinson, T. J. Pearson

    This paper has been withdrawn by the author(s), as it is superseded by 0708.2385.

  14. Yanqin Wu, Norman W. Murray, J. Michael Ramsahai

    Radial velocity surveys find Jupiter mass planets with semi-major axes a less than 0.1 AU around ~1% of solar-type stars; counting planets with $a$ as large as 5 AU, the fraction of stars having planets reaches ~ 10% {Marcy,Butler}. An examination of the distribution of semi-major axes shows that there is a clear excess of planets with orbital periods around

  15. P. P. Edmon, T. W. Jones, H. Kang

    We present results of time evolution of oblique MHD plane shocks including diffusive cosmic ray acceleration with backreaction on the plasma flows. The simulations include self-consistent effects of finite Alfven wave propagation and dissipation. From the computed cosmic ray particle phase space distributions we calculate expected leptonic and hadronic emiss

  16. Costas Kounnas, Herve Partouche

    In the framework of superstring compactifications with N=1 supersymmetry spontaneously broken, (by either geometrical fluxes, branes or else), we show the existence of new inflationary solutions. The time-trajectory of the scale factor of the metric a, the supersymmetry breaking scale m=m(Phi) and the temperature T are such that am and aT remain constant. Th

  17. Daniel Birmajer, Juan Gil, Michael Weiner

    We establish necessary and sufficient conditions for a quadratic polynomial to be irreducible in the ring $Z[[x]]$ of formal power series with integer coefficients. For $n,m\ge 1$ and $p$ prime, we show that $p^n+p^mβx+αx^2$ is reducible in $Z[[x]]$ if and only if it is reducible in $Z_p[x]$, the ring of polynomials over the $p$-adic integers.

  18. Stavros Garoufalidis

    Sequences that are defined by multisums of hypergeometric terms with compact support occur frequently in enumeration problems of combinatorics, algebraic geometry and perturbative quantum field theory. The standard recipe to study the asymptotic expansion of such sequences is to find a recurrence satisfied by them, convert it into a differential equation sat

  19. Alex Hayat, Meir Orenstein

    A novel concept of self-phasematched optical frequency conversion in dispersive dielectric microcavities is studied theoretically and experimentally. We develop a time-dependent model, incorporating the dispersion into the structure of the spatial cavity modes and translating the phasematching requirement into the optimization of a nonlinear cavity mode over

  20. Istvan Danko

    The CLEO-c experiment has been collecting data at the charm-threshold region. A selection of recent results on charmed meson and charmonia decays are presented.

  21. Ehud Fuchs, Michael Kroyter

    We find solutions of supersymmetric string field theory that correspond to the photon marginal deformation in the boundary conformal field theory. We revisit the bosonic string marginal deformation and generate a real solution for it. We find a map between the solutions of bosonic and supersymmetric string field theories and suggest a universal solution to s

  22. Aleksey Zinger

    We give an explicit formula for the difference between the standard and reduced genus-one Gromov-Witten invariants. Combined with previous work on geometric properties of the latter, this paper makes it possible to compute the standard genus-one GW-invariants of complete intersections. In particular, we obtain a closed formula for the genus-one GW-invariants

  23. M. M. Miller Bertolami, L. G. Althaus

    We present 1-D numerical simulations of the very late thermal pulse (VLTP) scenario for a wide range of remnant masses. We show that by taking into account the different possible remnant masses, the observed evolution of V4334 Sgr (a.k.a. Sakurai's Object) can be reproduced within the standard 1D-MLT stellar evolutionary models without the inclusion of a

  24. Laura Andrianopoli, Riccardo D'Auria, Emanuele Orazi, Mario Trigiante

    We show that the second order field equations characterizing extremal solutions for spherically symmetric, stationary black holes are in fact implied by a system of first order equations given in terms of a prepotential W. This confirms and generalizes the results in [14]. Moreover we prove that the squared prepotential function shares the same properties of

  25. Beniamino Cappelletti Montano, Luigia Di Terlizzi

    We regard a contact metric manifold whose Reeb vector field belongs to the $(κ,μ)$-nullity distribution as a bi-Legendrian manifold and we study its canonical bi-Legendrian structure. Then we characterize contact metric $(κ,μ)$-spaces in terms of a canonical connection which can be naturally defined on them.

  26. F. Delduc, E. Ivanov

    Elaborating on previous work (hep-th/0605211, hep-th/0611247), we show how the linear and nonlinear chiral multiplets of N=4 supersymmetric mechanics with the off-shell content (2,4,2) can be obtained by gauging three distinct two-parameter isometries of the ``root'' (4,4,0) multiplet actions. In particular, two different gauge groups, one abelian an

  27. Brendan Z. Foster

    "Einstein-aether" theory is a generally covariant theory of gravity containing a dynamical preferred frame. This article continues an examination of effects on the motion of binary pulsar systems in this theory, by incorporating effects due to strong fields in the vicinity of neutron star pulsars. These effects are included through an effective appro

  28. A. Berciano, R. Umble

    Let p be an odd prime. When n>2, we show that each tensor factor of form E \otimes Γin H(Z,n;Z_p) is an A-infinity bialgebra with non-trivial structure. We give explicit formulas for the structure maps and the quadratic relations among them. Thus E \otimes Γis a naturally occurring example of an A-infinity bialgebra whose internal structure is well-understoo

  29. R. Monaco, M. Aaroe, J. Mygind, V. P. Koshelets

    Traditionally, since the discovery of the Josephson effect in 1962, the magnetic diffraction pattern of planar Josephson tunnel junctions has been recorded with the field applied in the plane of the junction. Here we discuss the static junction properties in a transverse magnetic field where demagnetization effects imposed by the junction geometry and config

  30. Micah Warren, Yu Yuan

    We derive a Liouville type result for special Lagrangian equations with certain "convexity" and restricted linear growth assumptions on the solutions.

  31. Ch. C. Moustakidis

    The knowledge of the nuclear symmetry energy of hot neutron-rich matter is important for understanding the dynamical evolution of massive stars and the supernova explosion mechanisms. In particular, the electron capture rate on nuclei and/or free protons in presupernova explosions is especially sensitive to the symmetry energy at finite temperature. In view

  32. C. R. Das, S. Digal, T. R. Govindarajan

    We study finite temperature phase transition of neutral scalar field on a fuzzy sphere using Monte Carlo simulations. We work with the zero mode in the temporal directions, while the effects of the higher modes are taken care by the temperature dependence of r. In the numerical calculations we use "pseudo-heatbath" method which reduces the auto-corre

  33. Mireille Bousquet-Mélou, Yann Ponty

    Let a and b be two positive integers. A culminating path is a path of Z^2 that starts from (0,0), consists of steps (1,a) and (1,-b), stays above the x-axis and ends at the highest ordinate it ever reaches. These paths were first encountered in bioinformatics, in the analysis of similarity search algorithms. They are also related to certain models of Lorentz

  34. Johan Alwall, Tilman Plehn, Dave Rainwater

    We demonstrate the possibility of studying weakly interacting new particles in weak boson fusion, using the example of supersymmetric same-sign charginos. This signal could establish the existence of Majorana neutralinos and give access to their electroweak couplings. It can be observed over (supersymmetric) QCD backgrounds provided the charginos are light a

  35. Dimitar P. Guelev

    The paper presents probabilistic extensions of interval temporal logic (ITL) and duration calculus (DC) with infinite intervals and complete Hilbert-style proof systems for them. The completeness results are a strong completeness theorem for the system of probabilistic ITL with respect to an abstract semantics and a relative completeness theorem for the syst

  36. Yves Décanini, Antoine Folacci

    We provide irreducible expressions for the metric variations of the gravitational action terms constructed from the 17 curvature invariants of order six in derivatives of the metric tensor i.e. from the geometrical terms appearing in the diagonal heat-kernel or Gilkey-DeWitt coefficient $a_3$. We then express, for a four dimensional spacetime, the approximat

  37. Huayi Chen

    We give an upper bound for the maximal slope of the tensor product of several non-zero Hermitian vector bundles on the spectrum of an algebraic integer ring. By Minkowski's theorem, we need to estimate the Arakelov degree of an arbitrary Hermitian line subbundle $\bar M$ of the tensor product. In the case where the generic fiber of $M$ is semistable in t

  38. E. Mukhin, V. Tarasov, A. Varchenko

    We show that the algebra of commuting Hamiltonians of the homogeneous XXX Heisenberg model has simple spectrum on the subspace of singular vectors of the tensor product of two-dimensional $gl_2$-modules. As a byproduct we show that there exist exactly $\binom {n}{l}-\binom{n}{l-1}$ two-dimensional vector subspaces $V \subset \C[u]$ with a basis $f,g\in V$ su

  39. Tibor Antal, Ioana Bena, Michel Droz, Kirsten Martens

    Liesegang patterns emerge from precipitation processes and may be used to build bulk structures at submicron lengthscales. Thus they have significant potential for technological applications provided adequate methods of control can be devised. Here we describe a simple, physically realizable pattern-control based on the notion of driven precipitation, meanin

  40. Min Yan, Zhichao Ruan, Min Qiu

    It was proposed that perfect invisibility cloaks can be constructed for hiding objects from electromagnetic illumination (Pendry et al., Science 312, p. 1780). The cylindrical cloaks experimentally demonstrated (Schurig et al., Science 314, p. 997) and proposed (Cai et al., Nat. Photon. 1, p. 224) have however simplified material parameters in order to facil

  41. Bo Zhang, Carsten Henkel

    We compute the local spectrum of the magnetic field near a metallic microstructure at finite temperature. Our main focus is on deviations from a plane-layered geometry for which we review the main properties. Arbitrary geometries are handled with the help of numerical calculations based on surface integral equations. The magnetic noise shows a significant po

  42. Ye Wang, Prakash Ishwar

    The reconstruction of a deterministic data field from binary-quantized noisy observations of sensors which are randomly deployed over the field domain is studied. The study focuses on the extremes of lack of deterministic control in the sensor deployment, lack of knowledge of the noise distribution, and lack of sensing precision and reliability. Such adverse

  43. Mukund Rangamani, Simon F. Ross

    Analysing closed string tachyon condensation will improve our understanding of spacetime in string theory. We study the string spectrum on a BTZ black hole spacetime supported by NS-NS flux, which provides a calculable example where we would expect to find a quasi-localised tachyon. We find that there is a winding tachyon when the black hole horizon is small

  44. Riccardo Barbieri

    Elementary particle physics is the quadrant of nature whose laws can be written in a few lines with absolute precision and the greatest empirical adequacy. If this is the case, as I believe it is, it must be possible and is probably useful to introduce the students and the interested readers to the entire subject in a compact way. This is the main aim of the

  45. Dusa McDuff

    The main result of this note is that every closed Hamiltonian S^1 manifold is uniruled, i.e. it has a nonzero Gromov--Witten invariant one of whose constraints is a point. The proof uses the Seidel representation of π_1 of the Hamiltonian group in the small quantum homology of M as well as the blow up technique recently introduced by Hu, Li and Ruan. It appl

  46. Maxim Krikun

    We enumerate rooted triangulations of a sphere with multiple holes by the total number of edges and the length of each boundary component. The proof relies on a combinatorial identity due to W.T. Tutte.

  47. Nicolas Jacon, Cédric Lecouvey

    We study the crystal graphs of irreducible $U_{v}(\hat{sl}}_{e})$-modules of higher level l. Generalizing works of the first author, we obtain a simple description of the bijections between the classes of multipartitions which naturally label these graphs: the Uglov multipartitions. This is achieved by expliciting an embedding of the $U_{v}(\hat{sl}}_{e})$-c

  48. Yoshiharu Tanaka, Misao Sasaki

    We formulate nonlinear perturbations of a scalar field dominated universe on super-horizon scales. We consider the case of a single scalar field. We take the gradient expansion approach. We adopt the uniform Hubble slicing and derive the general solution valid to $O(ε^2)$, where $ε$ is the expansion parameter associated with a spatial derivative, which inclu

  49. Merab Gogberashvili, Pavle Midodashvili, Douglas Singleton

    We examine the behavior of fermions in the presence of an internal compact 2-manifold which in one of the spherical angles exhibits a conical character with an obtuse angle. The extra manifold can be pictured as an apple-like surface i.e. a sphere with an extra "wedge" insert. Such a surface has conical singularities at north and south poles. It is s

  50. Joaquim Gomis, Diederik Roest

    Recently a correspondence between non-propagating degrees of freedom in maximal supergravity and the very extended algebra E_11 has been found. We perform a similar analysis for a supergravity theory with eight supercharges and very extended G_2. In particular, in the context of d=5 minimal supergravity, we study whether supersymmetry can be realised on high

  51. Johannes Kofler, Caslav Brukner

    Why do we not experience a violation of macroscopic realism in every-day life? Normally, no violation can be seen either because of decoherence or the restriction of coarse-grained measurements, transforming the time evolution of any quantum state into a classical time evolution of a statistical mixture. We find the sufficient condition for these classical e

  52. Micha Berkooz, Zohar Komargodski, Dori Reichmann

    We study the thermal physics of AdS(3) and the BTZ black hole when embedded in String theory. The exact calculation of the Hagedorn temperature in TAdS(3) is reinterpreted as the appearance of a winding tachyon both in AdS(3) and BTZ. We construct a dual framework for analyzing the phases of the system. In this dual framework, tachyon condensation and geomet

  53. Antoine Ducros

    In this paper, we first study the local rings of a Berkovich analytic space from the point of view of commutative algebra. We show that those rings are excellent ; we introduce the notion of a an analytically separable extension of non-archimedean complete fields (it includes the case of the finite separable extensions, and also the case of any complete exte

  54. Oleg S. Ugolnikov, Igor A. Maslov

    The work contains the description of two narrow IR-bands observational data of total lunar eclipse of March, 3, 2007, one- and two-dimensional procedures of radiative transfer equation solution. The results of the procedure are the extinction values for atmospheric aerosol and water vapor at different altitudes in the troposphere along the Earth's termin

  55. M. Baldo, P. Schuck, X. Vinas

    A non-relativisitic nuclear density functional theory is constructed, not as usual, from an effective density dependent nucleon-nucleon force but directly introducing in the functional results from microscopic nuclear and neutron matter Bruckner G-matrix calculations at various densities. A purely phenomenological finite range part to account for surface pro

  56. Herintsitohaina Ratsimbarison

    This paper aims to give a probabilistic construction of interactions which may be relevant for building physical theories such as interacting quantum field theories. We start with the path integral definition of partition function in quantum field theory which recall us the probabilistic nature of this physical theory. From a Gaussian law considered as free

  57. Eugen Paal, Jyri Virkepu

    It is explained how the time evolution of the operadic variables may be introduced. As an example, an operadic Lax representation of the harmonic oscillator is considered.

  58. Alexander Viznyuk, Yuri Shtanov

    We investigate the braneworld model with induced gravity to clarify the role of the cross-over length scale \ell in the possible explanation of the dark-matter phenomenon in astrophysics and in cosmology. Observations of the 21 cm line from neutral hydrogen clouds in spiral galaxies reveal that the rotational velocities remain nearly constant at a value v_c

  59. Michal Chodorowski, Jean-Baptiste Coiffard, Maciej Bilicki, Stephane Colombi

    A comparison of the 2MASS flux dipole to the CMB dipole can serve as a method to constrain a combination of the cosmological parameter Omega_m and the luminosity bias of the 2MASS survey. For this constraint to be as tight as possible, it is necessary to maximize the correlation between the two dipoles. This can be achieved by optimizing the survey window th

  60. Yahya Ould Hamidoune

    Let $G$ be a group and let $X$ be a finite subset. The isoperimetric method investigates the objective function $|(XB)\setminus X|$, defined on the subsets $X$ with $|X|\ge k$ and $|G\setminus (XB)|\ge k$. A subset with minimal where this objective function attains its minimal value is called a $k$--fragment. In this paper we present all the basic facts abou

  61. Ivan V. Losev

    A Hamiltonian action of a complex torus on a symplectic complex manifold is said to be {\it multiplicity free} if a general orbit is a lagrangian submanifold. To any multiplicity free Hamiltonian action of a complex torus $T\cong (\C^\times)^n$ on a Stein manifold $X$ we assign a certain 5-tuple consisting of a Stein manifold $Y$, an étale map $Y\to \t^*$, a

  62. J. I. Vestgarden, D. V. Shantsev, Y. M. Galperin, T. H. Johansen

    The flux penetration near a semicircular indentation at the edge of a thin superconducting strip placed in a transverse magnetic field is investigated. The flux front distortion due to the indentation is calculated numerically by solving the Maxwell equations with a highly nonlinear $E(j)$ law. We find that the excess penetration, $Δ$, can be significantly (

  63. E. Kogan

    A mixture of light and heavy atoms is considered. We study the kinetics of the light atoms, scattered by the heavy ones, the latter undergoing slow diffusive motion. In three-dimensional space we claim the existence of a crossover region (in energy), which separates the states of the light atoms with fast diffusion and the states with slow diffusion; the lat

  64. Morten Brun, Gunnar Carlsson, Bjorn Ian Dundas

    We introduce the notion of "covering homology" of a commutative ring spectrum with respect to certain families of coverings of topological spaces. The construction of covering homology is extracted from Bokstedt, Hsiang and Madsen's topological cyclic homology. In fact covering homology with respect to the family of orientation preserving isogeni

  65. Douglas M. Gingrich

    Black holes could be produced at the Large Hadron Collider in TeV-scale gravity scenarios. We discuss missing energy mechanisms in black hole production and decay in large extra-dimensional models. In particular, we examine how graviton emission into the bulk could give the black hole enough recoil to leave the brane. Such a perturbation would cause an abrup

  66. Matt Visser

    This chapter provides a brief introduction to the Kerr spacetime and rotating black holes, touching on the most common coordinate representations of the spacetime metric and the key features of the geometry -- the presence of horizons and ergospheres. The coverage is by no means complete, and serves chiefly to orient oneself when reading subsequent chapters.

  67. Frederic Robert, Juncheng Wei

    We consider asymptotic behavior of the following fourth order equation \[ Δ^2 u= ρ\frac{e^{u}}{\int_\Om e^{u} dx} {in} \Om, u= \partial_νu=0 {on} \partial Ω\] where $\Om$ is a smooth oriented bounded domain in $\R^4$. Assuming that $0<ρ\leq C$, we completely characterize the asymptotic behavior of the unbounded solutions.

  68. Remco van der Hofstad, Mark Holmes

    We derive a perturbation expansion for general self-interacting random walks, where steps are made on the basis of the history of the path. Examples of models where this expansion applies are reinforced random walk, excited random walk, the true (weakly) self-avoiding walk, loop-erased random walk, and annealed random walk in random environment. In this pape

  69. Paul C. Clark, Simon C. O. Glover, Ralf S. Klessen

    We report results from numerical simulations of star formation in the early universe that focus on gas at very high densities and very low metallicities. We argue that the gas in the central regions of protogalactic halos will fragment as long as it carries sufficient angular momentum. Rotation leads to the build-up of massive disk-like structures which frag

  70. S. Capponi, G. Roux, P. Lecheminant, P. Azaria

    We study a simple model of N-component fermions with contact interactions which describes fermionic atoms with N=2F+1 hyperfine states loaded into a one-dimensional optical lattice. We show by means of analytical and numerical approaches that, for attractive interaction, a quasi-long-range molecular superfluid phase emerges at low density. In such a phase, t

  71. Fabio Musso, Matteo Petrera

    This paper has been withdrawn. The authors realized that the obtained results were not new.

  72. B. Bagchi

    We consider the specific models of Zhu-Kroemer and BenDaniel-Duke in a sech$^{2}$-mass background and point out interesting correspondences with the stationary 1-soliton and 2-soliton solutions of the KdV equation in a supersymmetric framework.

  73. Shintaro Ishiwata, Wataru Kobayashi, Ichiro Terasaki, Kenichi Kato

    Synchrotron X-ray diffraction patterns were measured and analyzed for a polycrystalline sample of the room-temperature ferromagnet Sr3.12Er0.88Co4O10.5 from 300 to 650 K, from which two structural phase transitions were found to occur successively. The higher-temperature transition at 509 K is driven by ordering of the oxygen vacancies, which is closely rela

  74. Vasudevan Srinivas, Wilberd van der Kallen

    Let G be GL_N or SL_N as reductive linear algebraic group over a field k of positive characteristic p. We prove several results that were previously established only when N < 6 or p > 2^N. Let G act rationally on a finitely generated commutative k-algebra A. Assume that A as a G-module has a good filtration or a Schur filtration. Let M be a noetherian A-modu

  75. G. W. Gibbons, S. N. Solodukhin

    In a previous paper we obtained formulae for the volume of a causal diamond or Alexandrov open set $I^+(p) \cap I^-(q)$ whose duration $τ(p,q) $ is short compared with the curvature scale. In the present paper we obtain asymptotic formulae valid when the point $q$ recedes to the future boundary ${\cal I}^+$ of an asymptotically de-Sitter spacetime. The volum

  76. Mauro Antezza, Franco Dalfovo, Lev P. Pitaevskii, Sandro Stringari

    We investigate the behavior of dark solitons in a superfluid Fermi gas along the BCS-BEC crossover by solving the Bogoliubov - de Gennes equations and looking for real and odd solutions for the order parameter. We show that in the resonance unitary region, where the scattering length is large, the density profile of the soliton has a deep minimum, differentl

  77. Martin Lustig, Yoav Moriah

    We define &#34;fat&#34; train tracks and use them to give a combinatorial criterion for the Hempel distance of Heegaard splittings for closed orientable 3-manifolds. We apply this criterion to 3-manifolds obtained from surgery on knots in the three sphere.

  78. K. V. Lukyanov, E. V. Zemlyanaya, I. N. Kuchtina, V. K. Lukyanov

    In the density distribution of a deformed target-nucleus, the spherical $λ= 0$ and the deformed $λ= 2$ parts were considered. On this basis, the corresponding potential parts $U_0$ and $U^{(2)}_{int}$ of a double -folding microscopic nucleus-nucleus optical potential are obtained. Then, for these potentials and by using the coupled-channel technique (ECIS),

  79. I. M. Dremin

    The coherent hadron production analogous to Cherenkov radiation of photons gives rise to the ring-like events. Being projected on the ring diameter they produce the two-bump structure recently observed for the away-side jets at RHIC. The position of the peaks and their height determine such properties of the hadronic medium as its nuclear refractive index, t

  80. Christoph A. Stephan

    We will present an extension of the standard model of particle physics in its almost-commutative formulation. This extension is guided by the minimal approach to almost-commutative geometries employed in [13], although the model presented here is not minimal itself. The corresponding almost-commutative geometry leads to a Yang-Mills-Higgs model which consist

  81. Vicente Muñoz

    Let $X$ be a smooth projective curve of genus $g\geq 2$ over the complex numbers. A holomorphic triple $(E_1,E_2,ϕ)$ on $X$ consists of two holomorphic vector bundles $E_1$ and $E_2$ over $X$ and a holomorphic map $ϕ:E_2 \to E_1$. There is a concept of stability for triples which depends on a real parameter $σ$. In this paper, we determine the Hodge polynomi

  82. Feng-Wen An

    In this paper we will first introduce the notion of affine structures on a ringed space and then obtain several properties. Affine structures on a ringed space, arising mainly from complex analytical spaces of algebraic schemes over number fields, behave like differential structures on a smooth manifold. As one does for differential manifolds, we will use ps

  83. Yoo Chung

    Resources in a distributed system can be identified using identifiers based on random numbers. When using a distributed hash table to resolve such identifiers to network locations, the straightforward approach is to store the network location directly in the hash table entry associated with an identifier. When a mobile host contains a large number of resourc

  84. Jayeeta Chowdhury, S. N. Karmakar, Bibhas Bhattacharyya

    We have studied a one dimensional Hubbard superlattice with different Coulomb correlations at alternating sites for a half-filled band. Mean field calculations based on the Hartree-Fock approximation together with a real space renormalization group technique were used to study the ground state of the system. The phase diagrams obtained in these approaches ag

  85. Zihua Weng

    Based on the concept of curved spacetime in Einsteinian General Relativity, the field theories and their quantum theories in the curved octonion spaces etc are discussed. The research results discover the close relationships of the curved spacetimes with the field theories and quantum theories. In the field theories of curved spacetimes, the curvatures have

  86. Yi-Fu Cai, Yi Wang

    We investigate the condition for eternal inflation to take place in the noncommutative spacetime. We find that the possibility for eternal inflation&#39;s happening is greatly suppressed in this case. If eternal inflation cannot happen in the low energy region where the noncommutativity is very weak (the UV region), it will never happen during the whole infl

  87. Jean-Luc Marichal

    We define the concept of weighted lattice polynomial functions as lattice polynomial functions constructed from both variables and parameters. We provide equivalent forms of these functions in an arbitrary bounded distributive lattice. We also show that these functions include the class of discrete Sugeno integrals and that they are characterized by a median

  88. Sara C. Beck, Jean L. Turner, Jenna Kloosterman

    The infrared spectra of starburst galaxies are dominated by the low-excitation lines of [NeII] and [SIII], and the stellar populations deduced from these spectra appear to lack stars larger than about 35 Msun. The only exceptions to this result until now were low metallicity dwarf galaxies. We report our analysis of the mid-infrared spectra obtained with IRS

  89. Shin-ichi Kato, Keiji Takano

    The notion of relative cuspidality for distinguished representations attached to $p$-adic symmetric spaces is introduced. A characterization of relative cuspidality in terms of Jacquet modules is given and a generalization of Jacquet&#39;s subrepresentation theorem to the relative case (symmetric space case) is established.

  90. Jianguo Cao, Bo Dai, Jiaqiang Mei

    In this paper, we study open complete metric spaces with non-negative curvature. Among other things, we establish an extension of Perelman&#39;s soul theorem for possibly singular spaces: &#34;Let X be a complete, non-compact, finite dimensional Alexandrov space with non-negative curvature. Suppose that X has no boundary and has positive curvature on a non-e

  91. Bernd Sturmfels, Josephine Yu

    The software TrIm offers implementations of tropical implicitization and tropical elimination, as developed by Tevelev and the authors. Given a polynomial map with generic coefficients, TrIm computes the tropical variety of the image. When the image is a hypersurface, the output is the Newton polytope of the defining polynomial. TrIm can thus be used to comp

  92. A. Stoykov, Y. Musienko, A. Kuznetsov, S. Reucroft

    The limited number of active pixels in a Geiger-mode Avalanche Photodiode (G-APD) results not only in a non-linearity but also in an additional fluctuation of its response. Both these effects are taken into account to calculate the amplitude resolution of an ideal G-APD, which is shown to be finite. As one of the consequences, the energy resolution of a scin

  93. Martin P. W. Zerner

    In this note we present a simplified proof of the zero-one law by Merkl and Zerner (2001) for directional transience of random walks in i.i.d. random environments (RWRE) on the square lattice. Also, we indicate how to construct a two-dimensional counterexample in a non-uniformly elliptic and stationary environment which has better ergodic properties than the

  94. Lawrence P. Roberts

    A companion paper to &#34;On knot Floer homology in branched double covers&#34; applied to braided branched loci. We reprove the main result of that paper concerning alternating branched loci when projected to an annulus, without using Khovanov homology. This provides two advantages: 1) the results hold for integer coefficients and 2) the spin^c structures a

  95. Sascha Husa, Jose A. Gonzalez, Mark Hannam, Bernd Bruegmann

    We describe a modification of a fourth-order accurate ``moving puncture&#39;&#39; evolution code, where by replacing spatial fourth-order accurate differencing operators in the bulk of the grid by a specific choice of sixth-order accurate stencils we gain significant improvements in accuracy. We illustrate the performance of the modified algorithm with an eq

  96. S. M. Shapiro, G. Xu, B. L. Winn, D. L. Schlagel

    Ti50 Pd50-xCrx is a high temperature shape memory alloy with a martensitic transformation temperature strongly dependent on the Cr composition. Prior to the transformation a premartensitic phase is present with an incommensurate modulated cubic lattice with wave vector of q0=(0.22, 0.22, 0). The temperature dependence of the diffuse scattering in the cubic p

  97. B. Habib, J. Shabani, E. P. De Poortere, M. Shayegan

    We report low-temperature resistance measurements in a modulation-doped, (311)A GaAs two-dimensional hole system as a function of applied in-plane strain. The data reveal a strong but anisotropic piezoresistance whose magnitude depends on the density as well as the direction along which the resistance is measured. At a density of $1.6\times10^{11}$ cm$^{-2}$

  98. A. V. Andreev

    The magnetoconductance of p-n junctions formed in clean single wall carbon nanotubes is studied in the noninteracting electron approximation and perturbatively in electron-electron interaction, in the geometry where a magnetic field is along the tube axis. For long junctions the low temperature magnetoconductance is anomalously large: the relative change in

  99. Jennifer L. Donovan, J. E. Hibbard, J. H. van Gorkom

    The focus of current research in galaxy evolution has increasingly turned to understanding the effect that mergers have on the evolution of systems on the red sequence. For those interactions purported to occur dissipationlessly (so called &#34;dry mergers&#34;), it would appear that the role of gas is minimal. However, if these mergers are not completely dr

  100. A. G. Angel, B. Schmittmann, R. K. P. Zia

    A generalized zero-range process with a limited number of long-range interactions is studied as an example of a transport process in which particles at a T-junction make a choice of which branch to take based on traffic levels on each branch. The system is analysed with a self-consistent mean-field approximation which allows phase diagrams to be constructed.