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June 2007 arXiv papers — page 19

Showing 1,801–1,900 of 4,521 papers

  1. M. Martinez-Canales, A. Bergara

    Recent reports of the melting curve of sodium at high pressure have shown that it has a very steep descent after a maximum of around 1000K at 31 GPa. This is not due to a phase transition. According to the Lindemann criterion, this behaviour should be apparent in the evolution of the Debye temperature with pressure. In this work, we have performed an "ab

  2. V. P. Goncalves, M. V. T. Machado

    In this contribution we study the photoproduction of quarkonium in coherent proton-proton and nucleus-nucleus interactions at the LHC. The integrated cross sections and rapidity distributions are estimated using the Color Glass Condensate (CGC) formalism, which takes into account the parton saturation effects at high energies. Nuclear shadowing effects are a

  3. Pablo Piantanida, Sajad Sadough, Pierre Duhamel

    The optimal decoder achieving the outage capacity under imperfect channel estimation is investigated. First, by searching into the family of nearest neighbor decoders, which can be easily implemented on most practical coded modulation systems, we derive a decoding metric that minimizes the average of the transmission error probability over all channel estima

  4. Anne-Laure Basdevant, Christina Goldschmidt

    We work in the context of the infinitely many alleles model. The allelic partition associated with a coalescent process started from n individuals is obtained by placing mutations along the skeleton of the coalescent tree; for each individual, we trace back to the most recent mutation affecting it and group together individuals whose most recent mutations ar

  5. Mans Henningson, Niclas Wyllard

    The low energy spectrum of (3+1)-dimensional N=4 supersymmetric Yang-Mills theory on a spatial three-torus contains a certain number of bound states, characterized by their discrete abelian magnetic and electric 't Hooft fluxes. At weak coupling, the wave-functions of these states are supported near points in the moduli space of flat connections where th

  6. Patricio S. Letelier

    Pairs potential-density in terms of elementary functions that represents flat rings structures are presented. We study structures representing one or several concentric flat rings. Also disks surrounded by concentric flat rings are exhibited. The stability of concentrically circular orbits of particles moving on a flat ring structure is analyzed for radial p

  7. Richard G. Edgar, Eric Blackman, Alice Quillen, Peggy Varniere

    We present computational results showing eccentricity growth in the inner portions of a protoplanetary disc. We attribute this to the evolving surface density of the disc. The planet creates a gap, which adjusts the balance between the 3:1 (eccentricity exciting) and 2:1 (eccentricity damping) resonances. The eccentricity of the inner disc can rise as high a

  8. Susan Kurien, Beth Wingate, Mark Taylor

    Rapidly rotating, stably stratified three-dimensional inviscid flows conserve both energy and potential enstrophy. We show that in such flows, the forward cascade of potential enstrophy imposes anisotropic constraints on the wavenumber distribution of kinetic and potential energy. The horizontal kinetic energy is suppressed in the large, nearly horizontal wa

  9. Jaromir Fiurasek, Ladislav Mista

    We investigate localization of entanglement of multimode Gaussian states into a pair of modes by local Gaussian measurements on the remaining modes and classical communication. We find that for pure states and for mixed symmetric states maximum entanglement between two modes can be localized by local homodyne detections, i.e. projections onto infinitely sque

  10. Lionel Bureau

    We perform drainage experiments of a linear alkane fluid (n-hexadecane) down to molecular thicknesses, and focus on the role played by the confinement rate. We show that molecular layering is strongly influenced by the velocity at which the confining walls are approached: under high enough shear rates, the confined medium behaves as a structureless liquid of

  11. Yang Huang, Jun She, Bo-Qiang Ma

    We use a new set of Collins functions to update a previous prediction on the azimuthal asymmetries of pion productions in semi-inclusive deep inelastic scattering (SIDIS) process on a transversely polarized nucleon target. We find that the calculated results can give a good explanation to the HERMES experiment with the new parametrization, and this can enric

  12. Pablo Piantanida, Pierre Duhamel

    In this paper, we examine the effects of imperfect channel estimation at the receiver and no channel knowledge at the transmitter on the capacity of the fading Costa's channel with channel state information non-causally known at the transmitter. We derive the optimal Dirty-paper coding (DPC) scheme and its corresponding achievable rates with the assumpti

  13. A. T. Raghavender, Damir Pajic, Kreso Zadro, Tomislav Milekovic

    Nanocrystalline Al-doped nickel ferrite powders have been synthesized by sol-gel auto-ignition method and the effect of non-magnetic aluminum content on the structural and magnetic properties has been studied. The X-ray diffraction (XRD) revealed that the powders obtained are single phase with inverse spinel structure. The calculated grain sizes from XRD dat

  14. Wojciech Roga, Mark Fannes, Karol Zyczkowski

    We introduce a composition of quantum states of a bipartite system which is based on the reshuffling of density matrices. This non-Abelian product is associative and stems from the composition of quantum maps acting on a simple quantum system. It induces a semi-group in the subset of states with maximally mixed partial traces. Subadditivity of the von Neuman

  15. Erwin Platen, Rien van de Weygaert, Bernard J. T. Jones

    On megaparsec scales the Universe is permeated by an intricate filigree of clusters, filaments, sheets and voids, the Cosmic Web. For the understanding of its dynamical and hierarchical history it is crucial to identify objectively its complex morphological components. One of the most characteristic aspects is that of the dominant underdense Voids, the produ

  16. Vincent Tisserand

    We present a review on the measurements of the CKM angle gamma (phi_3) as performed by the BABAR and Belle experiments at the asymmetric-energy e+e- B factories colliders PEP-II and KEKB.

  17. Peter Hegarty

    We refine previous results to provide examples, and in some cases precise classifications, of extremal subsets of {1,...,n} containing no solutions to a wide class of non-invariant, homogeneous linear equations in three variables, i.e.: equations of the form ax+by=cz with a+b \neq c.

  18. Eugenio Carretta, Angela Bragaglia, Raffaele Gratton

    In the framework of a project aiming at deriving in a homogeneous way the properties (age, distance, reddening and detailed chemical abundances) of a large sample of old open clusters, we present here the metal abundance and the abundance ratios of light (C, N, O, Na, Mg, Al, Si, Ca, Ti) and heavier (Cr, Mn, Ni, Ba, Eu) elements in the galactic open clusters

  19. M. Zgirski, K. Yu. Arutyunov

    The shape of experimentally observed R(T) transition of thin superconducting wires is analyzed. Broadening of the transition in quasi-1-dimensional superconducting channels is typically associated with phase slip mechanism provided by thermal or quantum fluctuations. It is shown that consideration of inevitable geometrical inhomogeneity and finite dimensions

  20. K. Yu. Arutyunov, T. T. Hongisto, D. Y. Vodolazov

    It is shown that in a structure consisting of a superconducting ring-shaped electrode overlapped by a normal metal contact through a thin oxide barrier, measurements of the tunnel current in magnetic field can probe persistent currents in the ring. The effect manifests itself as periodic oscillations of the tunnel current through the junction at a fixed bias

  21. A. Chigogidze, A. Nagorko

    We characterize maps between $n$-dimensional Nöbeling manifolds that can be approximated by homeomorphisms.

  22. Angela Bonaccorso

    This talk will review the status of art of nuclear and Coulomb breakup theories and their relation to optical models of elastic scattering of exotic projectiles. The effect of the final state interactions between the breakup particle and the core and target nuclei will be clarified and some typical numerical calculations for the relevant observables will be

  23. Nicolas Vuillerme, Nicolas Pinsault, Matthieu Boisgontier, Olivier Chenu

    The purpose of the present experiment was to investigate whether the sensory weighting of a plantar pressure-based, tongue-placed tactile biofeedback for controlling posture could be subject to inter-individual variability. To achieve this goal, 60 young healthy adults were asked to stand as immobile as possible with their eyes closed in two conditions of No

  24. E. Perfetto, J. Gonzalez

    We study the electronic instabilities in a 2D Hubbard model where one of the dimensions has a finite width, so that it can be considered as a large array of coupled chains. The finite transverse size of the system gives rise to a discrete string of Fermi points, with respective electron fields that, due to their mutual interaction, acquire anomalous scaling

  25. B. N. J. Persson

    I study the contact between a rigid solid with a randomly rough surface and an elastic block with a flat surface. I derive a relation between the (average) interfacial separation $u$ and the applied normal squeezing pressure $p$. I show that for non-adhesive inte raction and small applied pressure, p is proportional to exp (-u/u_0), in good agreement with re

  26. Bernd Braunecker, D. E. Feldman, Feifei Li

    We demonstrate that spin current can be generated by an ac voltage in a one-channel quantum wire with strong repulsive electron interactions in the presence of a non-magnetic impurity and uniform static magnetic field. In a certain range of voltages, the spin current can exhibit a power dependence on the ac voltage bias with a negative exponent. The spin cur

  27. T. Bertram, A. Eckart, S. Fischer, J. Zuther

    This paper addresses the global molecular gas properties of a representative sample of galaxies hosting low-luminosity quasistellar objects. An abundant supply of gas is necessary to fuel both the active galactic nucleus and any circum-nuclear starburst activity of QSOs. We selected a sample of nearby low-luminosity QSO host galaxies that is free of infrared

  28. A. Vershik, A. Gorbulsky

    We study the notion of the scaled entropy of a filtration of $σ$-fields (= decreasing sequence of $σ$-fields) introduced by the first author ({V4}). We suggest a method for computing this entropy for the sequence of $σ$-fields of pasts of a Markov process determined by a random walk over the trajectories of a Bernoulli action of a commutative or nilpotent co

  29. D. D. Bhaktavatsala Rao

    An exactly solvable model for the decoherence of one and two-qubit states interacting with a spin-bath, in the presence of a time-dependent magnetic field is studied. The magnetic field is static along $\hat{z}$ direction and oscillatory in the transverse plane. The transition probability and Rabi oscillations between the spin-states of a single qubit is sho

  30. Antonio Di Crescenzo, Elvira Di Nardo, Luigi M. Ricciardi

    We consider the first-crossing-time problem through a constant boundary for a Wiener process perturbed by random jumps driven by a counting process. On the base of a sample-path analysis of the jump-diffusion process we obtain explicit lower bounds for the first-crossing-time density and for the first-crossing-time distribution function. In the case of the d

  31. P. Q. Hung

    The possibility of constructing a model in which right-handed neutrinos have electroweak-scale masses as well as being {\em non-sterile} was espoused in Ref. 1. In this talk, I will review the ideas and results of Ref. 1 and discuss its implications for colliders such as the Tevatron, LHC and ILC.

  32. J. Ziegler, J. H. Snoeijer, J. Eggers

    When a solid plate is withdrawn from a liquid bath, a receding contact line is formed where solid, liquid, and gas meet. Above a critical speed $U_{cr}$, a stationary contact line can no longer exist and the solid will eventually be covered completely by a liquid film. Here we show that the bifurcation diagram of this coating transition changes qualitatively

  33. A. Bérard, H. Mohrbach, J. Lages, P. Gosselin

    In 1990, Dyson published a proof due to Feynman of the Maxwell equations assuming only the commutation relations between position and velocity. With this minimal assumption, Feynman never supposed the existence of Hamiltonian or Lagrangian formalism. In the present communication, we review the study of a relativistic particle using ``Feynman brackets.'&#

  34. Grigoris Panotopoulos

    In the present work we discuss cosmic strings in natural inflation. Our analysis is based entirely on the CMB quadrupole temperature anisotropy and on the existing upper bound on the cosmic string tension. Our results show that the allowed range for both parameters of the inflationary model is very different from the range obtained recently if cosmic strings

  35. Robert Koenig, Ueli Maurer, Stefano Tessaro

    A quantum storage device differs radically from a conventional physical storage device. Its state can be set to any value in a certain (infinite) state space, but in general every possible read operation yields only partial information about the stored state. The purpose of this paper is to initiate the study of a combinatorial abstraction, called abstract s

  36. M. F. Bode, D. J. Harman, T. J. O'Brien, H. E. Bond

    We report Hubble Space Telescope imaging obtained 155 days after the 2006 outburst of RS Ophiuchi. We detect extended emission in both [O III] and [Ne V] lines. In both lines, the remnant has a double ring structure. The E-W orientation and total extent of these structures (580+-50 AU at d=1.6kpc) is consistent with that expected due to expansion of emitting

  37. Bau-Sen Du

    In this note, we present a few methods (Theorems 1, 2, and 3) from discrete dynamical systems theory of obtaining new functions Q(n) from the known ones so that the dividing formulas n|Q(n) hold.

  38. The DELPHI Collaboration, J. Abdallah

    Neutral triple-gauge-boson couplings ZZZ, ZZgam and Zgamgam have been studied with the DELPHI detector using data at energies between 183 and 208 GeV. Limits are derived on these couplings from an analysis of the reactions e+e- -> Zgam, using data from the final states gamma f fbar, with f = q or neutrino, from e+e- -> ZZ, using data from the four-fermion fi

  39. Michael S. Bessell

    It is difficult to accurately measure the effective gravity (log g) in late-type stars using broadband (eg. UBV or SDSS) or intermediate-band (uvby) photometric systems, especially when the stars can cover a range of metallicities and reddenings. However, simple spectroscopic observational and data reduction techniques can yield accurate values for log g thr

  40. I. Bierenbaum, J. Blümlein, S. Klein

    The $O(α_s^2)$ massive operator matrix elements for unpolarized and polarized heavy flavor production at asymptotic values $Q^2 >> m^2$ are calculated in Mellin space without applying the integration-by-parts method. We confirm previous results given in Refs. \cite{BU1,BU2}, however, obtain much more compact representations.

  41. Hao-Yi Wan, Ze-Long Yi, Tong-Jie Zhang, Jie Zhou

    In this work, we use observations of the Hubble parameter from the differential ages of passively evolving galaxies and the recent detection of the Baryon Acoustic Oscillations (BAO) at $z_1=0.35$ to constrain the Dvali-Gabadadze-Porrati (DGP) universe. For the case with a curvature term, we set a prior $h=0.73\pm0.03$ and the best-fit values suggest a spati

  42. N. V. Mitskievich, V. N. Efremov, A. M. Hernández Magdaleno

    A model of topological field theory is presented in which the vacuum coupling constants are topological invariants of the four-dimensional spacetime. Thus the coupling constants are theoretically computable, and they indicate the topological structure of our universe.

  43. Gautam Chinta, Joel B. Mohler

    Friedberg, Hoffstein and Lieman have constructed two related multiple Dirichlet series from quadratic and higher-order $L$-functions and Gauss sums. We compute these multiple Dirichlet series explicitly in the case of the rational function field. This is done by utilizing the functional equation of the $L$-functions and the functional equation relating the t

  44. Wojciech Krolikowski

    A two-parameter neutrino mass formula is described, giving a moderately hierarchical spectrum m_1 < m_2 < m_3 consistent with the experimental estimates of Delta m^2_{21} and Delta m^2_{32}. The formula follows from a three-parameter empirical neutrino mass formula through imposing a parameter constraint and leads to a very simple neutrino mass sum rule m_3

  45. M. Beneke, Y. Kiyo, A. A. Penin

    We compute the third-order correction to electromagnetic S-wave quarkonium production and annihilation rates due to the emission and absorption of an ultrasoft gluon. Our result completes the analysis of the non-relativistic quarkonium bound-state dynamics in the next-to-next-to-next-to-leading order. The impact of the ultrasoft correction on the Upsilon(1S)

  46. Cyrille Chavet, Philippe Coussy, Pascal Urard, Eric Martin

    This paper presents a solution to efficiently explore the design space of communication adapters. In most digital signal processing (DSP) applications, the overall architecture of the system is significantly affected by communication architecture, so the designers need specifically optimized adapters. By explicitly modeling these communications within an eff

  47. Marc Chardin

    We investigate the behavior of Castelnuovo-Mumford regularity with respect to some classical functors : Tor, the Frobenius functor in positive characteristic, taking a power or a product (on ideals). These generalizes and refines previous results on these issues by several authors. As an application we provide results on the regularity of an intersection of

  48. N. Y. Hwang, S. -R. Eric Yang

    We have investigated the polarization dependence of the emission spectra of p-shell multiexcitons of a quantum dot when the single particle level spacing is larger than the characteristic energy of the Coulomb interactions. We find that there are many degenerate multiexciton states. The emission intensities depend on the number of degenerate initial and fina

  49. Matteo Cacciari

    We introduce the concept of the area of a jet, and show how it can be used to perform the subtraction of even a large amount of diffuse noise from hard jets.

  50. Guohun Zhu

    The Hamiltonian cycle problem in digraph is mapped into a matching cover bipartite graph. Based on this mapping, it is proved that determining existence a Hamiltonian cycle in graph is $O(n^3)$.

  51. S. Mieske, M. Hilker, A. Jordan, L. Infante

    Aim: To extend the investigations of ultra-compact dwarf galaxies (UCDs) beyond the well studied Fornax and Virgo clusters. Methods: We measured spectroscopic redshifts of about 400 compact object candidates with 19.2 < V < 22.4 mag in the central region of the Centaurus galaxy cluster (d=43Mpc), using VIMOS@VLT. The luminosity range of the candidates covers

  52. L. Chen, R. de Grijs, J. L. Zhao

    We derive the proper motions, membership probabilities, and velocity dispersions of stars in the regions of the young (about 2-4 Myr-old) open clusters NGC 2244 (the central cluster in the Monoceros R2 association) and NGC 6530 (the dominant cluster in the Sgr OB1 association) from photographic plate material obtained at Shanghai Astronomical Observatory, wi

  53. Andrea Banfi

    Three-jet event-shape distributions can be exploited to investigate the dependence of hadronisation effects on the colour and the geometry of the underlying hard event. We present here the first comparison of data in e+e- annihilation and state-of-the-art theoretical predictions, including resummation of large logarithms at next-to-leading logarithmic accura

  54. Pavel Kolesnikov

    In this note, we introduce a class of algebras that are in some sense related to conformal algebras. This class (called TC-algebras) includes Weyl algebras and some of their (associative and Lie) subalgebras. By a conformal algebra we generally mean what is known as $H$-pseudo-algebra over the polynomial Hopf algebra $H=\Bbbk[T_1,..., T_n]$. Some recent resu

  55. K. M. Tamizhmani, Basil Grammaticos, Alfred Ramani

    We examine whether the Painleve property is necessary for the integrability of partial differential equations (PDEs). We show that in analogy to what happens in the case of ordinary differential equations (ODEs) there exists a class of PDEs, integrable through linearisation, which do not possess the Painleve property. The same question is addressed in a disc

  56. Pavel Kolesnikov

    We distinguish a class of irreducible finite representations of conformal Lie (super)algebras. These representations (called universally defined) are the simplest ones from the computational point of view: a universally defined representation of a conformal Lie (super)algebra $L$ is completely determined by commutation relations of $L$ and by the requirement

  57. Richard P. Barber, David J. Popalisky, Rose Hacking, Kristina Chiapella

    In teaching the physical sciences, a significant challenge lies in the student&#39;s tendency to consider the scientific world and the &#34;real&#34; world as separate. For example, Newton&#39;s 1st Law of Motion states that an object in motion remains in motion in a straight line unless acted on by an external force. However, our experience tells us that mo

  58. Stephanie J. van Willigenburg

    We put forward a proof of Solomon&#39;s rule, in terms of matrices, for multiplication in the descent algebra of the symmetric group. Our proof exploits the graphs that we can obtain from all the subsets of the set of transpositions, $\{(i,i+1)\}_{i=1}^{n-1}$.

  59. Udo Baumgartner, Jacqui Ramagge, Bertrand Remy

    Let $G$ be an abstract Kac-Moody group over a finite field and $\bar{G}$ be the closure of the image of $G$ in the automorphism group of its positive building. We show that if the Dynkin diagram associated to $G$ is irreducible and neither of spherical nor of affine type, then the contraction groups of elements in $\bar{G}$ which are not topologically period

  60. Haining Li, Hong Wu, Chen Cao, Yinan Zhu

    We explore the correlation between morphological types and mid-infrared (MIR) properties of an optically flux-limited sample of 154 galaxies from the Forth Data Release (DR4) of Sloan Digital Sky Survey (SDSS), cross-correlated with Spitzer SWIRE (Spitzer Wide-Area InfraRed Extragalactic Survey) fields of ELAIS-N1, ELAIS-N2 and Lockman Hole. Aperture photome

  61. N. Bergeron, S. J. van Willigenburg

    Here we give a combinatorial interpretation of Solomon&#39;s rule for multiplication in the descent algebra of Weyl groups of type $D$, $ΣD_n$. From here we show that $ΣD_n$ is a homomorphic image of the descent algebra of the hyperoctahedral group, $ΣB_{n-2}$.

  62. F E Close

    Donald Rumsfeld, in attempting to excuse the inexcusable, once (in)famously said that ``there are things that we know we know; there are things that we know we don&#39;t know; and then there are things that we don&#39;t know that we don&#39;t know&#34;. Recent discoveries about hadrons with heavy flavours fall into those categories. It is of course the third

  63. Tapan K. Nayak

    The event-by-event analysis of high energy nuclear collisions aims at revealing the richness of the underlying event structures and provide unique measures of dynamical fluctuations associated with QGP phase transition. The major challenge in these studies is to separate the dynamical fluctuations from the many other sources which contribute to the measured

  64. M. D. Atkinson, S. J. van Willigenburg

    The descent algebra of the symmetric group, over a field of non-zero characteristic p, is studied. A homomorphism into the algebra of generalised p-modular characters of the symmetric group is defined. This is then used to determine the radical, and its nilpotency index. It also allows the irreducible representations of the descent algebra to be described.

  65. Katsuyoshi Ohara, Nobuki Takayama

    We introduce A-hypergeometric differential-difference equation and prove that its holonomic rank is equal to the normalized volume of A with giving a set of convergent series solutions.

  66. U. Al Khawaja

    We derive exact solitonic solutions of the one-dimensional time-dependent Gross-Pitaevskii equation with time-dependent strengths of the harmonic external potential and the interatomic interaction. The time-dependence of the external potential and interatomic interaction are given in terms of a general function of time. For an oscillating strength of the ext

  67. U. Al Khawaja

    We derive classes of exact solitonic solutions of the time-dependent Gross-Pitaevskii equation with repulsive and attractive interatomic interactions. The solutions correspond to a string of bright solitons with phase difference between adjacent solitons equal to $π$. While the relative phase, width, and distance between adjacent solitons turn out to be a co

  68. Garcia de Andrade

    The topological mapping between a torus of big radius and a sphere is applied to the Riemannian geometry of a stretched and twisted very thick magnetic flux tube, to obtain spherical dynamos solving the magnetohydrodynamics (MHD) self-induction equation for the magnetic flux tubes undergoing differential (non-uniform) rotation along the tube magnetic axis. C

  69. N. Tsoneva, H. Lenske

    The evolution of the PDR strength with the neutron excess is investigated in Sn isotopic and N=82 isotonic chains with regard to its possible connection with the neutron skin thickness. For this purpose a recently proposed method incorporating both HFB and multi-phonon QPM theory is applied. Analysis of the corresponding neutron and proton dipole transition

  70. Yukio Nemoto, Masakiyo Kitazawa, Teiji Kunihiro

    We investigate the quark spectrum near but above the critical temperature of the chiral transition, taking into account the precursory soft modes. It is found that there appear novel excitation spectra of quasi-quarks and quasi-antiquarks with a three-peak structure. By a detailed analysis on the formation of the three-peak structure using Yukawa models, it

  71. Takahiro Kudoh, Shantanu Basu, Youichi Ogata, Takashi Yabe

    We employ the first fully three-dimensional simulation to study the role of magnetic fields and ion-neutral friction in regulating gravitationally-driven fragmentation of molecular clouds. The cores in an initially subcritical cloud develop gradually over an ambipolar diffusion time while the cores in an initially supercritical cloud develop in a dynamical t

  72. H. F. Arellano, Eric Bauge

    By examining the structure in momentum and coordinate space of a two-body interaction spherically symmetric in its local coordinate, we demonstrate that it can be disentangled into two distinctive contributions. One of them is a medium-independent and momentum-conserving term, whereas the other is functionally --and exclusively-- proportional to the radial d

  73. R. Foot

    A mirror sector of particles and forces provides a simple explanation of the inferred dark matter of the Universe. The status of this theory is reviewed - with emphasis on how the theory explains the impressive DAMA/NaI annual modulation signal, whilst also being consistent with the null results of the other direct detection experiments.

  74. H. F. Arellano, M. Girod

    Microscopic optical model potential results for reaction cross sections of proton elastic scattering are presented. The applications cover the 10-1000 MeV energy range and consider both stable and unstable nuclei. The study is based on in-medium g-matrix full-folding optical model approach with the appropriate relativistic kinematic corrections needed for th

  75. R. Mathieu, J. P. He, Y. Kaneko, H. Yoshino

    The ac-susceptibility of the electron doped single-layered manganite La$_{1.1}$Sr$_{0.9}$MnO$_4$ is analyzed in detail. A quasi two-dimensional (2$D$) antiferromagnetic (AFM) order with Ising anisotropy is stabilized below $T_N$ $\sim$ 80K. We show that below $T_N$, a rare 2$D$ spin-glass (SG) correlation develops with the same Ising anisotropy as the AFM st

  76. Alfio Bonanno, Vadim Urpin

    We study the stability of a compressible magnetic plane Couette flow and show that compressibility profoundly alters the stability properties if the magnetic field has a component perpendicular to the direction of flow. The necessary condition of a newly found instability can be satisfied in a wide variety of flows in laboratory and astrophysical conditions.

  77. R. Bertacco, S. Brivio, M. Cantoni, A. Cattoni

    We report about La0.67Sr0.33MnO3 single crystal manganite thin films in interaction with a gold capping layer. With respect to uncoated manganite layers of the same thickness, Au-capped 4 nm-thick manganite films reveal a dramatic reduction (about 185 K) of the Curie temperature TC and a lower saturation low-temperature magnetization M0. A sizeable TC reduct

  78. Ivan Cheltsov

    We study global log canonical thresholds of cubic surfaces with canonical singularities, and we prove the existence of a Kahler-Einstein metric on two singular cubic surfaces.

  79. Robert L. Singleton

    This is the first of two lectures on a new powerful technique employed by Brown, Preston, and Singleton (BPS) to calculate transport quantities in a plasma. This exposition will be self-contained and intended for those who are not specialists in quantum field theory, where the technique of dimensional continuation exploited by BPS first arose. The method is

  80. Omer Friedland, Sasha Sodin

    We demonstrate a simple analytic argument that may be used to bound the Levy concentration function of a sum of independent random variables. The main application is a version of a recent inequality due to Rudelson and Vershynin, and its multidimensional generalisation.

  81. Myron Bander, Jonathan L. Feng, Arvind Rajaraman, Yuri Shirman

    Unparticles from hidden conformal sectors provide qualitatively new possibilities for physics beyond the standard model. In the theoretical framework of minimal models, we clarify the relation between energy scales entering various phenomenological analyses. We show that these relations always counteract the effective field theory intuition that higher dimen

  82. Y. Onose, N. P. Ong, C. Petrovic

    The thermal Hall conductivity $κ_{xy}$ and Hall conductivity $σ_{xy}$ in CeCoIn$_5$ are used to determine the Lorenz number ${\cal L}_H$ at low temperature $T$. This enables the separation of the observed thermal conductivity into its electronic and non-electronic parts. We uncover evidence for a charge-neutral, field-dependent thermal conductivity, which we

  83. Alexei Borodin, Christopher D. Sinclair

    We give a closed form for the correlation functions of ensembles of asymmetric real matrices in terms of the Pfaffian of an antisymmetric matrix formed from a $2 \times 2$ matrix kernel associated to the ensemble. We also derive closed forms for the matrix kernel and correlation functions for Ginibre&#39;s real ensemble.

  84. Hiroshi de Sandes, Rogerio Rosenfeld

    In this letter we study the process of gluon fusion into a pair of Higgs bosons in a model with one universal extra dimension. We find that the contributions from the extra top quark Kaluza-Klein excitations lead to a Higgs pair production cross section at the LHC that can be significantly altered compared to the Standard Model value for small values of the

  85. Brandon Buckley, Georg H. Hoffstaetter

    One of the main concerns in the design of low emittance linear accelerators (linacs) is the preservation of beam emittance. Here we discuss one possible source of emittance dilution, the coupler kick, due to transverse electromagnetic fields in the accelerating cavities of the linac caused by the power coupler geometry. In addition to emittance growth, the c

  86. Suk Bum Chung, Hendrik Bluhm, Eun-Ah Kim

    We consider the stability conditions for half-quantum vortices in quasi two dimensional $p_x+ip_y$ superconductor (such as ${\rm Sr_2 RuO_4}$ is believed to be) through energetics calculations. Although the predicted exotic nature of these excitations have recently attracted much attention but they have not been observed yet. We pay particular attention to t

  87. Vincenzo Chilla

    This paper is concerned with the subduction problem of type A quantum Iwahori-Hecke algebras $\mathbb{C} \mathbf{H}(\mathfrak{S}_f,q^2)$ with a real deformation parameter $q$, i.e. the problem of decomposing irreducible representations of such algebras as direct sum of irreducible representations of the subalgebras $\mathbb{C}\mathbf{H}(\mathfrak{S}_{f_1}, q

  88. P. A. Oesch, M. Stiavelli, C. M. Carollo, L. E. Bergeron

    We present the UDF05 project, a HST Large Program of deep ACS (F606W, F775W, F850LP) and NICMOS (F110W, F160W) imaging of three fields, two of which coincide with the NICP1-4 NICMOS parallel observations of the Hubble Ultra Deep Field (HUDF). In this first paper we use the ACS data for the NICP12 field, as well as the original HUDF ACS data, to measure the U

  89. Erhai Zhao, Arun Paramekanti

    Building on work by Florens and Georges, we formulate and study a self-consistent slave rotor mean field theory for strongly correlated systems. This approach views the electron, in the strong correlation regime, as a composite of a neutral spinon and a charged rotor field. We solve the coupled spinon-rotor model self-consistently using a cluster mean field

  90. Paul Hunt, Subir Sarkar

    Detailed analyses of the WMAP data indicate possible oscillatory features in the primordial curvature perturbation, which moreover appears to be suppressed beyond the present Hubble radius. Such deviations from the usual inflationary expectation of an approximately Harrison-Zeldovich spectrum are expected in the supergravity-based &#39;multiple inflation&#39

  91. Volker Bromm, Abraham Loeb

    Current observations are about to open up a direct window into the final frontier of cosmology: the first billion years in cosmic history when the first stars and galaxies formed. Even before the launch of the James Webb Space Telescope, it might be possible to utilize Gamma-ray Bursts (GRBs) as unique probes of cosmic star formation and the state of the int

  92. Yao Cheng, Bing Xia

    We report experimental observations of the long-lived rhodium Mossbauer emissions by the time- and energy-resolved spectroscopy. The extraordinary observations manifest the open-up of photonic band gap in analogy to the superconducting gap of remarkable symmetry breakings at transition point. These observations are of potential importance for detecting gravi

  93. Michal Spalinski

    The inflationary flow equations are a frequently used method of surveying the space of inflationary models. In these applications the infinite hierarchy of differential equations is truncated in a way which has been shown to be equivalent to restricting the set of models considered to those characterized by polynomial inflaton potentials. This paper explores

  94. Zuoqin Wang

    The &#34;twisted Mellin transform&#34; is a slightly modified version of the usual classical Mellin transform on $L^2(\mathbb R)$. In this short note we investigate some of its basic properties. From the point of views of combinatorics one of its most important interesting properties is that it intertwines the differential operator, $df/dx$, with its finite

  95. Huayi Chen

    We propose a generalization of Quillen&#39;s exact category -- arithmetic exact category and we discuss conditions on such categories under which one can establish the notion of Harder-Narasimhan filtrations and Harder-Narsimhan polygons. Furthermore, we show the functoriality of Harder-Narasimhan filtrations (indexed by $\mathbb R$), which can not be stated

  96. Terence Tao

    By using a multiscale analysis, we establish quantitative versions of the Besicovitch projection theorem (almost every projection of a purely unrectifiable set in the plane of finite length has measure zero) and a standard companion result, namely that any planar set with at least two projections of measure zero is purely unrectifiable. We illustrate these r

  97. Andrew S. Raich, Emil J. Straube

    Let $Ω\subset\C^n$ be a bounded smooth pseudoconvex domain. We show that compactness of the complex Green operator $G_{q}$ on $(0,q)$-forms on $bΩ$ implies compactness of the $\bar{\partial}$-Neumann operator $N_{q}$ on $Ω$. We prove that if $1 \leq q \leq n-2$ and $bΩ$ satisfies $(P_q)$ and $(P_{n-q-1})$, then $G_{q}$ is a compact operator (and so is $G_{n-

  98. Vern I. Paulsen, Mrinal Raghupathi

    Anderson&#39;s paving conjectures are known to be equivalent to the Kadison-Singer problem. We prove some new equivalences of Anderson&#39;s conjectures that require the paving of smaller sets of matrices. We prove that if the strictly upper triangular operatorss are pavable, then every 0 diagonal operator is pavable. This result follows from a new paving co

  99. Wolfgang P. Angerer

    We introduce a Mellin transform of functions which live on all of $\bR$ and discuss its applications to the limiting theory of Bellman-Harris processes, and specifically Luria-Delbrück processes. More precisely, we calculate the life-time distribution of particles in a Bellman-Harris process from their first-generation offspring and limiting distributions, a

  100. X. Aslanoglou, N. Bakirci, S. Cerci, A. Cyz

    We present results of the performance of the second prototype of the CASTOR quartz-tungsten sampling calorimeter, to be installed in the very forward region of the CMS experiment at the LHC. The energy linearity and resolution, as well as the spatial resolution of the prototype to electromagnetic and hadronic showers are studied with E=20-200 GeV electrons,