Research archive

arXiv papers from September 2009

The most recent 100 records published that month. Open any paper for its original abstract, citation metadata, related research, and reading tools.

  1. Alvaro Corral

    We explore in depth the validity of a recently proposed scaling law for earthquake interevent time distributions in the case of the Southern California, using the waveform cross-correlation catalog of Shearer et al. Two statistical tests are used: on the one hand, the standard two-sample Kolmogorov-Smirnov test is in agreement with the scaling of the distrib

  2. Albert Osso, Alvaro Corral, J. E. Llebot

    The influence of climate variability and global warming on the occurrence of tropical cyclones (TC) is a controversial issue. Existing historical databases on the subject are not fully reliable, but a more fundamental hindrance is the lack of basic understanding regarding the intrinsic nature of tropical cyclone genesis and evolution. It is known that tropic

  3. Harald W. Griesshammer, Deepshikha Shukla

    We present recent results on elastic deuteron Compton scattering calculations for polarised beans and targets up to next-to-leading order within Chiral Effective Field Theory in the Small Scale Expansion variant to implement a dynamical \Delta(1232) degree of freedom. A simple power-counting argument discloses that np-intermediate rescattering states must be

  4. N. T. Zinner

    We consider a fully polarized ultracold Fermi gas interacting through a p-wave Feshbach resonance. Using a two-channel model, we find the effective potential at the point where the p-wave scattering length goes to zero. Here the effective interaction provides attraction and one can therefore ask about the stability of the system. We calculate the energy dens

  5. Frank Pollmann, Joel E. Moore

    The entanglement spectrum of a pure state of a bipartite system is the full set of eigenvalues of the reduced density matrix obtained from tracing out one part. Such spectra are known in several cases to contain important information beyond that in the entanglement entropy. This paper studies the entanglement spectrum for a variety of critical and near-criti

  6. Bruno Bellomo, Rosario Lo Franco, Sabrina Maniscalco, Giuseppe Compagno

    We study the time behavior of entanglement between two noninteracting qubits each immersed in its own environment for two different non-Markovian conditions: a high-$Q$ cavity slightly off-resonant with the qubit transition frequency and a nonperfect photonic band-gap, respectively. We find that revivals and retardation of entanglement loss may occur by adju

  7. Avner Friedman, Bei Hu, Chuan Xue

    Chronic wounds represent a major public health problem affecting 6.5 million people in the United States. Ischemia represents a serious complicating factor in wound healing. In this paper we analyze a recently developed mathematical model of ischemic dermal wounds. The model consists of a coupled system of partial differential equations in the partially heal

  8. Edray Herber Goins

    We show that, for all odd natural numbers $N$, the $N$-torsion points on an elliptic curve may be placed in an $N \times N$ grid such that the sum of each column and each row is the point at infinity.

  9. Steven Gottlieb, L. Levkova, M. Di Pierro, A. El-Khadra

    We update results presented at Lattice 2005 on charmonium masses. New ensembles of gauge configurations with 2+1 flavors of improved staggered quarks have been analyzed. Statistics have been increased for other ensembles. New results are also available for P-wave mesons and for bottomonium on selected ensembles.

  10. Edray Herber Goins, Talitha M. Washington

    Differential Calculus is a staple of the college mathematics major's diet. Eventually one becomes tired of the same routine, and wishes for a more diverse meal. The college math major may seek to generalize applications of the derivative that involve functions of more than one variable, and thus enjoy a course on Multivariate Calculus. We serve this article

  11. Maud Galametz, Suzanne Madden, Frederic Galliano, Sacha Hony

    We present 870 micron images of four low metallicity galaxies (NGC1705, Haro11, Mrk1089 and UM311) observed with the Large APEX BOlometer CAmera (LABOCA). We model their spectral energy distributions combining the submm observations of LABOCA, 2MASS, IRAS, Spitzer photometric data and the IRS data for Haro11. We find that a significant mass of dust is reveal

  12. Bruno Grenet

    In 1931, G\"odel presented in K\"onigsberg his famous Incompleteness Theorem, stating that some true mathematical statements are unprovable. Yet, this result gives us no idea about those independent (that is, true and unprovable) statements, about their frequency, the reason they are unprovable, and so on. Calude and J\"urgensen proved in 2005 Chaitin's "heu

  13. Murray W. McCutcheon, Georg W. Rieger, Jeff F. Young, Dan Dalacu

    We demonstrate tunable frequency-converted light mediated by a chi-(2) nonlinear photonic crystal nanocavity. The wavelength-scale InP-based cavity supports two closely-spaced localized modes near 1550 nm which are resonantly excited by a 130 fs laser pulse. The cavity is simultaneously irradiated with a non-resonant probe beam, giving rise to rich second-or

  14. Leonardo T. Rolla, Vladas Sidoravicius, Donatas Surgailis, Maria E. Vares

    In this work we introduce the discrete-space broken line process (with discrete and continues parameter values) and derive some of its properties. We explore polygonal Markov fields techniques developed by Arak-Surgailis. The discrete version is presented first and a natural continuum generalization to a continuous object living on the discrete lattice is th

  15. Steven Klee

    It is verified that the number of vertices in a $d$-dimensional cubical pseudomanifold is at least $2^{d+1}$. Using Adin's cubical $h$-vector, the generalized lower bound conjecture is established for all cubical 4-spheres, as well as for some special classes cubical spheres in higher dimensions.

  16. Michael Goff

    Upper bounds on the topological Betti numbers of Vietoris-Rips complexes are established, and examples of such complexes with high Betti numbers are given.

  17. T. P. Doerr, Yi-Kuo Yu

    An exact, analytic solution for a simple electrostatic model applicable to biomolecular recognition is presented. In the model, a layer of high dielectric constant material (representative of the solvent, water) whose thickness may vary separates two regions of low dielectric constant material (representative of proteins, DNA, RNA, or similar materials), in

  18. H. B. Benaoum

    In this paper, we introduce the h-analogue of Fibonacci numbers for non-commutative h-plane. For h h'= 1 and h = 0, these are just the usual Fibonacci numbers as it should be. We also derive a collection of identities for these numbers. Furthermore, h-Binet's formula for the h-Fibonacci numbers is found and the generating function that generates these number

  19. Alexander Punnoose

    Renormalization group equations are derived for the case when both valley splitting and intervalley scattering are present in a two-valley system. A third scaling parameter is shown to be relevant when the two bands are split but otherwise distinct. The existence of this parameter changes the quantitative behavior at finite temperatures, but the qualitative

  20. Adel B. Badi

    We prove an index theorem for Toeplitz operators on irreducible tube--type domains and we extend our results to Toeplitz operators with matrix symbols. In order to prove our index theorem, we proved a result asserting that a non--vanishing function on the Shilov boundary of a tube--type bounded symmetric domain, not necessarily irreducible, is equal to a uni

  21. G. Mazzarella, L. Salasnich

    We study triaxial bright solitons made of attractive Bose-condensed atoms characterized by the absence of confinement in the longitudinal axial direction but trapped by an anisotropic harmonic potential in the transverse plane. By numerically solving the three-dimensional Gross-Pitaevskii equation we investigate the effect of the transverse trap anisotropy o

  22. E. A. Hoversten, C. Gronwall, D. E. Vanden Berk, T. S. Koch

    Deep Swift UV/Optical Telescope (UVOT) imaging of the Chandra Deep Field South is used to measure galaxy number counts in three near ultraviolet (NUV) filters (uvw2: 1928 A, uvm2: 2246 A, uvw1: 2600 A) and the u band (3645 A). UVOT observations cover the break in the slope of the NUV number counts with greater precision than the number counts by the Hubble S

  23. R Aros, D E Diaz

    We continue the study of a special entry in the AdS/CFT dictionary, namely a holographic formula relating the functional determinant of the scattering operator in an asymptotically locally anti-de Sitter (ALAdS) space to a relative functional determinant of the scalar Laplacian in the bulk. A heuristic derivation of the formula involves a one-loop quantum ef

  24. Peter M. Goldreich, Jonathan L. Mitchell

    A number of synchronous moons are thought to harbor water oceans beneath their outer ice shells. A subsurface ocean frictionally decouples the shell from the interior. This has led to proposals that a weak tidal or atmospheric torque might cause the shell to rotate differentially with respect to the synchronously rotating interior. As a result of centrifugal

  25. Lucas Platter

    The pionless effective field theory (EFT) is the appropriate low-energy EFT for short-range interactions that display a large scattering length. It has been successfully applied in atomic, nuclear and particle physics. We give an overview over recent calculations employing the pionless effective field theory and lay emphasis on applications in the three- and

  26. Michelangelo L. Mangano

    We review here the prospects of a long-term upgrade programme for the Large Hadron Collider (LHC), CERN laboratory's new proton-proton collider. The super-LHC, which is currently under evaluation and design, is expected to deliver of the order of ten times the statistics of the LHC. In addition to a non-technical summary of the principal physics arguments fo

  27. Jinsheng Wen, Guangyong Xu, Zhijun Xu, Zhi Wei Lin

    Inelastic neutron scattering and susceptibility measurements have been performed on the optimally-doped Fe-based superconductor FeTe(0.5)Se(0.5), which has a critical temperature, Tc of 14 K. The magnetic scattering at the stripe antiferromagnetic wave-vector Q = (0.5,0.5) exhibits a "resonance" at ~ 6 meV, where the scattering intensity increases abruptly w

  28. Anne Pellerin, Gerhardt R. Meurer, Kenji Bekki, Debra M. Elmegreen

    We studied the star cluster population properties in the nearby collisional ring galaxy NGC 922 using HST/WFPC2 photometry and population synthesis modeling. We found that 69% of the detected clusters are younger than 7 Myr, and that most of them are located in the ring or along the bar, consistent with the strong Halpha emission. The images also show a tida

  29. P. D. Gujrati

    Starting from the second law of thermodynamics applied to an isolated system consisting of the system surrounded by an extremely large medium, we formulate a general non-equilibrium thermodynamic description of the system when it is out of equilibrium. We then apply it to study the structural relaxation in glasses and establish the phenomenology behind the c

  30. E. T. Million, S. W. Allen, N. Werner, G. B. Taylor

    (abridged) We report results from a Chandra study of the central regions of the nearby, X-ray bright, Ophiuchus Cluster (z = 0.03), the second-brightest cluster in the sky. Our study reveals a dramatic, close-up view of the stripping and potential destruction of a cool core within a rich cluster. The X-ray emission from the Ophiuchus Cluster core exhibits a

  31. Eric Greenwood

    We investigate the effect on the Hawking radiation given off during the time of collapse of a Reisner-Nordstr\"om domain wall. Using the functional Schr\"odinger formalism we are able to probe the time-dependent regime, which is out of the reach of the standard approximations like the Bogolyubov method. We calculate the occupation number of particles for a s

  32. Mariusz P. Dabrowski, Tomasz Denkiewicz

    We discuss various types of exotic (non-standard) singularities in the Universe: a Big-Rip (BR or type I), a Sudden Future Singularity (SFS or type II), a Generalized Sudden Future Singularity, a Finite Scale Factor singularity (FSF or type III), a Big-Separation (BS or type IV) and a $w$-singularity. They are characterized by violation of all or some of the

  33. Anne Pellerin, Steven L. Finkelstein

    With the coming generation of instruments and telescopes capable of spectroscopy of high redshift galaxies, the spectral synthesis technique in the rest-frame UV and Far-UV range will become one of a few number of tools remaining to study their young stellar populations in detail. The rest-frame UV lines and continuum of high redshift galaxies, observed with

  34. G. Chartas, C. Saez, W. N. Brandt, M. Giustini

    We present results from multi-epoch spectral analysis of XMM-Newton and Chandra observations of the broad absorption line (BAL) quasar APM 08279+5255. Our analysis shows significant X-ray BALs in all epochs with rest-frame energies lying in the range of ~ 6.7-18 keV. The X-ray BALs and 0.2-10 keV continuum show significant variability on timescales as short

  35. Eric J. Murphy

    (Abridged) I present a predictive analysis for the behavior of the FIR--radio correlation as a function of redshift in light of the deep radio continuum surveys which may become possible using the SKA. To keep a fixed ratio between the FIR and predominantly non-thermal radio continuum emission of a normal star-forming galaxy requires a nearly constant ratio

  36. Vitor Cardoso, Oscar J. C. Dias, Jorge V. Rocha

    Plasma balls and rings emerge as fluid holographic duals of black holes and black rings in the hydrodynamic/gravity correspondence for the Scherk-Schwarz AdS system. Recently, plasma balls spinning above a critical rotation were found to be unstable against m-lobed perturbations. In the phase diagram of stationary solutions the threshold of the instability s

  37. A. M. Fischer, A. B. Dzyubenko, R. A. Roemer

    We study optically-induced collective excitations of graphene in the presence of a strong perpendicular magnetic field and a single impurity. We determine the energies and absorption strengths of these excitations, which become localised on the impurity. Two different types of impurity are considered i. the long-range Coulomb impurity, ii. a delta-function i

  38. Rebecca G. Martin, Christopher A. Tout, J. E. Pringle

    The low-mass X-ray binary microquasar GRO J1655-40 is observed to have a misalignment between the jets and the binary orbital plane. Since the current black hole spin axis is likely to be parallel to the jets, this implies a misalignment between the spin axis of the black hole and the binary orbital plane. It is likely the black holes formed with an asymmetr

  39. Lia R. Corrales, Zoltán Haiman, Andrew MacFadyen

    Finding electromagnetic (EM) counterparts of future gravitational wave (GW) sources would bring rich scientific benefits. A promising possibility, in the case of the coalescence of a super-massive black hole binary (SMBHB), is that prompt emission from merger-induced disturbances in a supersonic circumbinary disk may be detectable. We follow the post-merger

  40. Salvatore M. Giampaolo, Fabrizio Illuminati

    We discuss the phenomenon of long-distance entanglement in the ground state of quantum spin models, its use in high-fidelity and robust quantum communication, and its realization in many-body systems of ultracold atoms in optical lattices and in arrays of coupled optical cavities. We investigate different patterns of site-dependent interaction couplings, sin

  41. Chiara Tonini, Claudia Maraston, Daniel Thomas, Julien Devriendt

    In a recent paper we presented the first semi-analytic model of galaxy formation in which the Thermally-Pulsing Asymptotic Giant Branch phase of stellar evolution has been fully implemented. Here we address the comparison with observations, and show how the TP-AGB recipe affects the performance of the model in reproducing the colours and near-IR luminosities

  42. Mikolas Janota, Joao Marques-Silva, Radu Grigore

    This short note reviews briefly three algorithms for finding the set of dispensable variables of a boolean formula. The presentation is light on proofs and heavy on intuitions.

  43. Bing An Li

    Decay $\Upsilon(1s)\to\gamma f_2(1270)$ is studied by an approach in which the tensor meson, $f_2(1270)$, is strongly coupled to gluons. Besides the strong suppression of the amplitude $\Upsilon(1s)\to\gamma gg, gg\to f_2$ by the mass of b-quark, d-wave dominance in $\Upsilon(1s)\to\gamma f_2(1270)$ is revealed from this approach, which provides a large enha

  44. Stephen R. Kane, Suvrath Mahadevan, Kaspar von Braun, Gregory Laughlin

    Transiting planet discoveries have yielded a plethora of information regarding the internal structure and atmospheres of extra-solar planets. These discoveries have been restricted to the low-periastron distance regime due to the bias inherent in the geometric transit probability. Monitoring known radial velocity planets at predicted transit times is a prove

  45. J. Xavier Prochaska, Gabor Worseck, John M. O'Meara

    We present a new method to directly measure the opacity from HI Lyman limit (LL) absorption k_LL along quasar sightlines by the intergalactic medium (IGM). The approach analyzes the average (``stacked'') spectrum of an ensemble of quasars at a common redshift to infer the mean free path (MFP) to ionizing radiation. We apply this technique to 1800 quasars at

  46. Alex Golovin, Kirill Sokolovsky, Natalia Virnina, Javier Lopez Santiago

    We report the discovery of three new variable stars in Indus: USNO-B1.0 0311-0760061, USNO-B1.0 0309-0771315, and USNO-B1.0 0315-0775167. Light curves of 3712 stars in a 87' x 58' field centered on the asynchronous polar CD Ind were obtained using a remotely controlled 150 mm telescope of Tzec Maun Observatory (Pingelly, Western Australia). The VaST software

  47. Lynda Cockins, Yoichi Miyahara, Steven D. Bennett, Aashish A. Clerk

    Strong confinement of charges in few electron systems such as in atoms, molecules and quantum dots leads to a spectrum of discrete energy levels that are often shared by several degenerate quantum states. Since the electronic structure is key to understanding their chemical properties, methods that probe these energy levels in situ are important. We show how

  48. Imke Schneider, Sebastian Eggert

    We derive a powerful yet simple method for analyzing the local density of states in gapless one dimensional fermionic systems, including extensions such as momentum dependent interaction parameters and hard-wall boundaries. We study the crossover of the local DOS from individual density waves to the well-known asymptotic powerlaws and identify characteristic

  49. Holger Baumgardt, Genevieve Parmentier, Mark Gieles, Enrico Vesperini

    We investigate the ratio between the half-mass radii r_h of Galactic globular clusters and their Jacobi radii r_J given by the potential of the Milky Way and show that clusters with galactocentric distances R_{GC}>8 kpc fall into two distinct groups: one group of compact, tidally-underfilling clusters with r_h/r_J<0.05 and another group of tidally filling cl

  50. Zhi-Wei Sun

    Let $p$ be an odd prime and let $a,m$ be integers with $a>0$ and $m \not\equiv0\pmod p$. In this paper we determine $\sum_{k=0}^{p^a-1}\binom{2k}{k+d}/m^k$ mod $p^2$ for $d=0,1$; for example, $$\sum_{k=0}^{p^a-1}\frac{\binom{2k}k}{m^k}\equiv\left(\frac{m^2-4m}{p^a}\right)+\left(\frac{m^2-4m}{p^{a-1}}\right)u_{p-(\frac{m^2-4m}{p})}\pmod{p^2},$$ where $(-)$ is

  51. Mu-Chun Chen, K. T. Mahanthappa, Felix Yu

    We propose a Randall-Sundrum model with a bulk family symmetry based on the double tetrahedral group, T', which generates the tri-bimaximal neutrino mixing pattern and a realistic CKM matrix. The T' symmetry forbids tree-level flavor-changing-neutral-currents in both the quark and lepton sectors, as different generations of fermions are unified into multiple

  52. Mu-Chun Chen, K. T. Mahanthappa

    We propose the complex group theoretical Clebsch-Gordon coefficients as a novel origin of CP violation. This is manifest in our model based on SU(5) combined with the double tetrahedral group, T'. Due to the presence of the doublet representations in $T^{\prime}$, there exist complex CG coefficients, leading to explicit CP violation in the model, while the Y

  53. Chul Kim, Thomas Mehen

    Several models of new physics, such as grand unified theories, Pati-Salam models, chiral color models, etc., predict the existence of an $SU(2)_L$ doublet of color-octet scalars (COS). In the Manohar-Wise model, the Yukawa couplings of the COS are assumed to be consistent with Minimal Flavor Violation ensuring constraints from flavor physics are satisfied ev

  54. D. M. Lindemann

    We present a search for the radiative leptonic decays B+ -> e+ nu gamma and B+ -> mu+ nu gamma using data collected by the BABAR detector at the PEP-II B factory. We fully reconstruct the hadronic decay of one of the B mesons in Upsilon(4S) -> B+B- and then search for evidence of the signal decay within the rest of the event. This method provides clean kinem

  55. Jesus Martin Romero, Mauricio Bellini

    Using some ideas of Modern Kaluza-Klein theory, we examine the evolution of entropy on a 4D Friedmann-Robertson-Walker (FRW) brane from a 5D vacuum state, which is defined on a 5D background Riemann-flat metric. We found that entropy production is sufficiently important during inflation: $S > 10^{90}$, for all the initial values of temperature $T_0 < T_{GU}$

  56. C. A. Bertulani, A. Gade

    The quest to comprehend how nuclear processes influence astrophysical phenomena is driving experimental and theoretical research programs worldwide. One of the main goals in nuclear astrophysics is to understand how energy is generated in stars, how elements are synthesized in stellar events and what the nature of neutron stars is. New experimental capabilit

  57. Yi Cai, David E. Kaplan, Markus A. Luty

    Particles with TeV mass and strong self-interactions generically have the right annihilation cross section to explain an observed excess of cosmic electrons and positrons if the end-product of the annihilation is charged leptons. We present an explicit model of strongly-coupled TeV-scale dark matter whose relic abundance related to the matter-antimatter asym

  58. Eleni Vardoulaki, Steve Rawlings, Gary J. Hill, Tom Mauch

    We present optical spectroscopy, near-infrared (mostly K-band) and radio (151-MHz and 1.4-GHz) imaging of the first complete region (TOOT00) of the TexOx-1000 (TOOT) redshift survey of radio sources. The 0.0015-sr (~ 5 deg^2) TOOT00 region is selected from pointed observations of the Cambridge Low-Frequency Survey Telescope at 151 MHz at a flux density limit

  59. S. Fournais, A. Kachmar

    We consider the two-dimensional Ginzburg-Landau functional with constant applied magnetic field. For applied magnetic fields close to the second critical field $H_{C_2}$ and large Ginzburg-Landau parameter, we provide leading order estimates on the energy of minimizing configurations. We obtain a fine threshold value of the applied magnetic field for which b

  60. D. Falie

    3D Time-of-Flight camera's images are affected by errors due to the diffuse (indirect) light and to the flare light. The presented method improves the 3D image reducing the distance's errors to dark surface objects. This is achieved by placing one or two contrast tags in the scene at different distances from the ToF camera. The white and black parts of the t

  61. W. E. A. Lorenz, R. O. Kuzian, S. -L. Drechsler, W. -D. Stein

    We present an inelastic neutron scattering investigation of Li2CuO2 detecting the long sought quasi-1D magnetic excitations with a large dispersion along the CuO2-chains studied up to 25 meV. The total dispersion is governed by a surprisingly large ferromagnetic (FM) nearest-neighbor exchange integral J1=-228 K. An anomalous quartic dispersion near the zone

  62. M. Eshaghi Gordji, M. Bavand Savadkouhi, Th. M. Rassias

    In this paper, we prove generalized Hyres--Ulam--Rassias stability of the mixed type additive, quadratic and cubic functional equation $$f(x+ky)+f(x-ky)=k^2f(x+y)+k^2f(x-y)+2(1-k^2)f(x)$$ for fixed integers $k$ with $k\neq0,\pm1$ in non-Archimedean spaces.

  63. Angelo Alvino, Roberta Volpicelli, Bruno Volzone

    In this paper we study some improvements of the classical Hardy inequality. We add to the right hand side of the inequality a term which depends on some Lorentz norms of $u$ or of its gradient and we find the best values of the constants for remaining terms. In both cases we show that the problem of finding the optimal value of the constant can be reduced to

  64. B. Bahr, B. Dittrich

    We discuss the fate of diffeomorphism symmetry in discrete gravity. Diffeomorphism symmetry is typically broken by the discretization. This has repercussions for the observable content and the canonical formulation of the theory. It might however be possible to construct discrete actions, so--called perfect actions, with exact symmetries and we will review f

  65. Jan Draisma, Eyal Kushilevitz, Enav Weinreb

    Consider the "Number in Hand" multiparty communication complexity model, where k players holding inputs x_1,...,x_k in {0,1}^n communicate to compute the value f(x_1,...,x_k) of a function f known to all of them. The main lower bound technique for the communication complexity of such problems is that of partition arguments: partition the k players into two d

  66. E. R. P. Novais, A. P. Guimarães

    Magnetic disks or dots of soft magnetic material of sub-micron dimensions may have as the lowest energy magnetic configuration a single-domain structure, with magnetization either perpendicular of parallel to the plane, or else may form magnetic vortices. The properties of these vortices may be used to encode data bits, in magnetic memory applications. In th

  67. E. V. Ferapontov, K. R. Khusnutdinova, C. Klein

    We investigate $(d+1)$-dimensional quasilinear systems which are integrable by the method of hydrodynamic reductions. In the case $d\geq 3$ we formulate a conjecture that any such system with an irreducible dispersion relation must be linearly degenerate. We prove this conjecture in the 2-component case, providing a complete classification of multi-dimension

  68. Masoud Kamgarpour, Teruji Thomas

    We sharpen the orbit method for finite groups of small nilpotence class by associating representations to functionals on the corresponding Lie rings. This amounts to describing compatible intertwiners between representations parameterized by an additional choice of polarization. Our construction is motivated by the theory of the linearized Weil representatio

  69. Alberto Annovi

    At the Fermilab Tevatron, the CDF detector is used to study diboson production in $p\bar{p}$ collisions at $\sqrt{s}$ = 1.96 TeV. We report recent diboson production measurements, limits on anomalous triple gauge couplings and latest results from semi-leptonic diboson searches.

  70. Daniel M. Kane, Samuel A. Kutin

    We consider quantum interpolation of polynomials. We imagine a quantum computer with black-box access to input/output pairs (x_i, f(x_i)), where f is a degree-d polynomial, and we wish to compute f(0). We give asymptotically tight quantum lower bounds for this problem, even in the case where 0 is among the possible values of x_i.

  71. B. Béri

    We show that time-reversal invariant superconductors in d=2 (d=3) dimensions can support topologically stable Fermi points (lines), characterized by an integer topological charge. Combining this with the momentum space symmetries present, we prove analogs of the fermion doubling theorem: for d=2 lattice models admitting a spin X electron-hole structure, the

  72. Volker Braun

    A three-generation SU(5) GUT, that is 3x(10+5bar) and a single 5-5bar pair, is constructed by compactification of the E_8 heterotic string. The base manifold is the Z_5 x Z_5-quotient of the quintic, and the vector bundle is the quotient of a positive monad. The group action on the monad and its bundle-valued cohomology is discussed in detail, including topo

  73. Kory Stiffler

    A brief historical synopsis of the connection between gauge theories and string theory is given. Meson configurations known as k-strings are examined from string theory via the gauge/gravity correspondence. Backgrounds dual to k-strings in both 2+1 and 3+1 are discussed. The energy of k-strings to lowest order consists of a tension term, proportional to the

  74. Albert Villanova del Moral

    Searches at the LHC of lepton flavour violation (LFV) in slepton decays can indirectly test both type-I and II seesaw mechanisms. Assuming universal flavour-blind boundary conditions, LFV in the neutrino sector is related to LFV in the slepton sector by means of the renormalization group equations. Ratios of LFV slepton decay rates result to be a very effect

  75. A. Couture, R. Reifarth

    We simulated the response of a 4p calorimetric g-detector array to decays of radioactive isotopes on the s-process path. The GEANT 3.21 simulation package was used. The main table contains estimates on the maximum sample size and required neutron flux based on the latest available neutron capture cross section at 30 keV. The results are intended to be used t

  76. Brendan Lucier

    We study the design of mechanisms in combinatorial auction domains. We focus on settings where the auction is repeated, motivated by auctions for licenses or advertising space. We consider models of agent behaviour in which they either apply common learning techniques to minimize the regret of their bidding strategies, or apply short-sighted best-response st

  77. Jan Draisma, Ron Shaw

    We prove that an alternating e-form on a vector space over a quasi-algebraically closed field always has a singular (e-1)-dimensional subspace, provided that the dimension of the space is strictly greater than e. Here an (e-1)-dimensional subspace is called singular if pairing it with the e-form yields zero. By the theorem of Chevalley and Warning our result

  78. M. Eshaghi Gordji, S. Abbaszadeh, Th. M. Rassias

    In this paper, we generalize the Mazur--Ulam theorem in the fuzzy real n-normed strictly convex spaces.

  79. David Maxwell

    We investigate the possibility that the conformal and conformal thin sandwich (CTS) methods can be used to parameterize the set of solutions of the vacuum Einstein constraint equations. To this end we develop a model problem obtained by taking the quotient of certain symmetric data on conformally flat tori. Specializing the model problem to a three-parameter

  80. Christian P. Robert, Kerrie L. Mengersen, Carla Chen

    The new perspectives on ABC and Bayesian model criticisms presented in Ratmann et al.(2009) are challenging standard approaches to Bayesian model choice. We discuss here some issues arising from the authors' approach, including prior influence, model assessment and criticism, and the meaning of error in ABC.

  81. Kostas Skenderis, Marika Taylor, Balt C. van Rees

    The AdS/CFT correspondence provides a new perspective on recurrent questions in General Relativity such as the allowed boundary conditions at infinity and the definition of gravitational conserved charges. Here we review the main insights obtained in this direction over the last decade and apply the new techniques to Topologically Massive Gravity. We show th

  82. Günther Hörmann

    We set-up and solve the Cauchy problem for Schr\"odinger-type differential operators with generalized functions as coefficients, in particular, allowing for distributional coefficients in the principal part. Equations involving such kind of operators appeared in models of deep earth seismology. We prove existence and uniqueness of Colombeau generalized solut

  83. Bruce Gilligan, Karl Oeljeklaus

    We give a precise characterization when a compact homogeneous CR-solvmanifold is CR-embeddable in a Kahler manifold. Equivalently this gives a non-Kahler criterion for complex manifolds containing CR-solvmanifolds not satisfying these conditions. This paper is the natural continuation of [OR] and [GOR].

  84. Vladislav V. Kravchenko, Sébastien Tremblay

    In [8] it was shown that the transplant operator transforms solutions of one Vekua equation into solutions of another Vekua equation, related to the first via a Schr\"odinger equation. In this paper we demonstrate a fundamental property of this operator: it transforms formal powers of the first Vekua equation into formal powers of the same order for the seco

  85. Alexander A. Davydov, Massimo Giulietti, Stefano Marcugini, Fernanda Pambianco

    We propose geometrical methods for constructing square 01-matrices with the same number n of units in every row and column, and such that any two rows of the matrix contain at most one unit in common. These matrices are equivalent to n-regular bipartite graphs without 4-cycles, and therefore can be used for the construction of efficient bipartite-graph codes

  86. Henry Towsner

    The Furstenberg-Zimmer structure theorem for $\mathbb{Z}^d$ actions says that every measure-preserving system can be decomposed into a tower of primitive extensions. Furstenberg and Katznelson used this analysis to prove the multidimensional Szemer\'edi's theorem, and Bergelson and Liebman further generalized to a polynomial Szemer\'edi's theorem. Beleznay a

  87. Mario Bessa, Maria Carvalho

    We show that for any positive forward density subset N \subset Z, there exists an integer m>0, such that, for all n>m, N contains almost perfect n-scaled reproductions of any previously chosen finite set of integers.

  88. Elizabeth Jenista, Ashley Stokes, Rosa Branca, Warren Warren

    A recent quantum computing paper (G. S. Uhrig, Phys Rev Lett 98 100504 (2007)) analytically derived optimal pulse spacings for a multiple spin echo sequence designed to remove decoherence in a two level system coupled to a bath. The spacings in what has been called a UDD sequence differ dramatically from the conventional, equal pulse spacing of a Carr-Purcel

  89. Julian Rincon, D. J. Garcia, K. Hallberg

    A distributed-memory parallelization strategy for the density matrix renormalization group is proposed for cases where correlation functions are required. This new strategy has substantial improvements with respect to previous works. A scalability analysis shows an overall serial fraction of 9.4% and an efficiency of around 60% considering up to eight nodes.

  90. Ts. Enkhbat

    It is well known that the supersymmetric finite threshold effects can induce substantial corrections to the Standard Model fermion masses. This opens an alternative possibility to correct the problematic mass ratios of the lighter generations within the minimal SU(5) GUT. We show that with large soft A--terms, one can achieve simple unification for lighter g

  91. Francisco S. N. Lobo, Miguel A. Oliveira

    In this work, we construct traversable wormhole geometries in the context of f(R) modified theories of gravity. We impose that the matter threading the wormhole satisfies the energy conditions, so that it is the effective stress-energy tensor containing higher order curvature derivatives that is responsible for the null energy condition violation. Thus, the

  92. Y. O. Hamidoune

    Let $\Gamma =(V,E)$ be a reflexive relation with a transitive automorphisms group. Let $v\in V$ and let $F$ be a finite subset of $V$ with $v\in F.$ We prove that the size of $\Gamma (F)$ (the image of $F$) is at least $$ |F|+ |\Gamma (v)|-|\Gamma ^- (v)\cap F|.$$ Let $A,B$ be finite subsets of a group $G.$ Applied to Cayley graphs, our result reduces to fol

  93. Chris Kottke

    We prove an index theorem for families of pseudodifferential operators generalizing those studied by C. Callias, N. Anghel and others. Specifically, we consider operators on a manifold with boundary equipped with an asymptotically conic (scattering) metric, which have the form D + i \Phi, where D is elliptic pseudodifferential with Hermitian symbols, and \Ph

  94. E. Ostrovsky L. Sirota

    In this article we obtain the non - asymptotical low estimations for bilinear Riesz's functional through the Lebesgue spaces norms by means of building of some examples.

  95. G. J. Conduit, B. D. Simons

    We present a microscopic model of the quantum paraelectric-ferroelectric phase transition with a focus on the influence of coupled fluctuating phonon modes. These may drive the continuous phase transition first order through a metaelectric transition and furthermore stimulate the emergence of a textured phase that preempts the transition. We discuss two furt

  96. Harald O. Jeschke, Hem C. Kandpal, Ingo Opahle, Yu-Zhong Zhang

    We present a detailed study of the derivation of the Hubbard model parameters for $\kappa$-(ET)$_2$Cu$_2$(CN)$_3$ in the framework of {\it ab initio} Density Functional Theory. We show that calculations with different (i) wavefunction basis, (ii) exchange correlation functionals and (iii) tight-binding models provide a reliable benchmark for the parameter va

  97. Chantal Valeriani, Philip J. Camp, Jos W. Zwanikken, René van Roij

    The problem of successfully simulating ionic fluids at low temperature and low density states is well known in the simulation literature: using conventional methods, the system is not able to equilibrate rapidly due to the presence of strongly associated cation-anion pairs. In this manuscript we present a numerical method for speeding up computer simulations

  98. Dipti Banerjee

    We have studied the formation of Hall-qubit (LLL state) in Quantum Hall effect due to the Aharonov-Bhom oscillation of quasiparticles.The spin echo method plays the key role in the topological entanglement of qubits. The proper ratio of fluxes for maximally entangling qubits has also been pointed out. The generation of higher Quantum Hall state may be possib

  99. Nathan Killoran, Devon N. Biggerstaff, Rainer Kaltenbaek, Kevin J. Resch

    Remote state preparation (RSP) is the act of preparing a quantum state at a remote location without actually transmitting the state itself. Using at most two classical bits and a single shared maximally entangled state, one can in theory remotely prepare any qubit state with certainty and with perfect fidelity. However, in any experimental implementation the

  100. Tamal K. Dey, Jian Sun, Yusu Wang

    Inference of topological and geometric attributes of a hidden manifold from its point data is a fundamental problem arising in many scientific studies and engineering applications. In this paper we present an algorithm to compute a set of loops from a point data that presumably sample a smooth manifold $M\subset \mathbb{R}^d$. These loops approximate a {\em