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August 2010 arXiv papers — page 37

Showing 3,6013,700 of 5,306 papers

  1. Ognian Kassabov, Adrijan Borisov

    Some curvature properties of Kahler manifolds of indefinite metrics are studied. Analogues of a Kulkarni's theorem are proved for such manifolds.

  2. D. Usachov, D. Haberer, A. Grüneis, H. Sachdev

    We demonstrate that freeing a single-atom thick layer of hexagonal boron nitride (hbn) from tight chemical bonding to a Ni(111) thin film grown on a W(110) substrate can be achieved by intercalation of Au atoms into the interface. This process has been systematically investigated using angle-resolved photoemission spectroscopy, X-ray photoemission and absorp

  3. D. Riquelme, M. A. Amo-Baladron, J. Martin-Pintado, R. Mauersberger

    Ams: We study the 12C/13C isotopic ratio in the disk of the central molecular zone and in the halo to trace gas accretion toward the Galactic center region in the Milky Way. Methods: Using the IRAM 30m telescope, we observe the J=1-0 rotational transition of HCO+, HCN, HNC and their 13C isotopic substitutions in order to measure the 12C/13C isotopic ratio. W

  4. C. P. Martin

    We propose a method for constructing Yukawa terms for noncommutative SO(10) and E6 GUTs, when these GUTs are formulated within the enveloping-algebra formalism. The most general noncommutative Yukawa term that we propose contains, at first order in thetamunu, the most general BRS invariant Yukawa contribution whose only dimensionful parameter is the noncommu

  5. R. Parimala, J. -P. Tignol, R. M. Weiss

    We prove: (1) The group of multipliers of similitudes of a 12-dimensional anisotropic quadratic form over a field K with trivial discriminant and split Clifford invariant is generated by norms from quadratic extensions E/K such that q_E is hyperbolic. (2) If G is the group of K-rational points of an absolutely simple algebraic group whose Tits index is E_{8,

  6. Bjoern Baeuchle, Marcus Bleicher

    Direct photon emission in heavy-ion collisions is calculated within a relativistic micro+macro hybrid model and compared to the microscopic transport model UrQMD. In the hybrid approach, the high-density part of the collision is calculated by an ideal 3+1-dimensional hydrodynamic calculation, while the early (pre-equilibrium-) and late (rescattering-) phase

  7. Sonny Ben-Shimon, Asaf Ferber, Dan Hefetz, Michael Krivelevich

    We study Maker-Breaker games played on the edge set of a random graph. Specifically, we consider the random graph process and analyze the first time in a typical random graph process that Maker starts having a winning strategy for his final graph to admit some property $\mP$. We focus on three natural properties for Maker's graph, namely being $k$-vertex

  8. Melsik K. Kyuregyan, Gohar M. Kyureghyan

    The paper studies constructions of irreducible polynomials over finite fields using polynomial composition method.

  9. Bjoern Baeuchle, Marcus Bleicher

    Direct photon spectra are calculated within a transport+hydrodynamics hybrid approach, in which the high-density part of the transport evolution has been replaced by a 3+1-dimensional hydrodynamic calculation. We study the effects of changing the parameters of the two interfaces between the transport- and hydrodynamic descriptions on the resulting direct pho

  10. Reza Torabi

    Based on quantum mechanical approach the polarization transport of photons which propagate in a medium with slow varying refractive index is studied. The photon polarizations are separated in opposite directions normal to the ray which is called "Spin Hall effect" of photons, and also the rotation of polarization plane, a manifestation of the Berry p

  11. Zbigniew Idziaszek, Tommaso Calarco, Peter Zoller

    We propose and analyze a scheme for sympathetic cooling of the translational motion of polar molecules in an optical lattice, interacting one by one with laser-cooled ions in a radio-frequency trap. The energy gap between the excitation spectra of the particles in their respective trapping potentials is bridged by means of a parametric resonance, provided by

  12. Fang Su, Ya-Dong Yang

    According to the heavy-quark flavour symmetry, the $B\to π, K$ transition form factors could be related to the corresponding ones of D-meson decays near the zero recoil point. With the recent precisely measured exclusive semileptonic decays $D \to π\ell ν$ and $D\to K \ell ν$, we perform a phenomenological study of $B \to π, K$ transition form factors based

  13. Mauricio Godoy Molina, Erlend Grong, Irina Markina, Fátima Silva Leite

    We present an intrinsic formulation of the kinematic problem of two $n-$dimensional manifolds rolling one on another without twisting or slipping. We determine the configuration space of the system, which is an $\frac{n(n+3)}2-$dimensional manifold. The conditions of no-twisting and no-slipping are decoded by means of a distribution of rank $n$. We compare t

  14. Tonghai Yang

    In this paper, we prove an explicit arithmetic intersection formula between arithmetic Hirzebruch-Zagier divisors and arithmetic CM cycles in a Hilbert modular surface over $\mathbb Z$. As applications, we obtain the first `non-abelian' Chowla-Selberg formula, which is a special case of Colmez's conjecture; an explicit arithmetic intersection formula

  15. Tonghai Yang

    In this paper, we obtain an explicit arithmetic intersection formula on a Hilbert modular surface between the diagonal embedding of the modular curve and a CM cycle associated to a non-biquadratic CM quartic field. This confirms a special case of the author's conjecture with J. Bruinier in \cite{BY}, and is a generalization of the beautiful factorization

  16. Kamaljit I. Lakhtaria, Dr. N. N. Jani

    Next generation networks (NGN) services are assumed to be a new revenue stream for both network operators and service providers. New services especially focused on a mobile telecommunications that would be used not only as a communication de vice but also as a personal gateway to order or consume a variety of services and products [1]. This type of advanced

  17. Dmitri I. Panyushev

    Let $g$ be a simple Lie algebra and $Ab(g)$ the set of Abelian ideals of a Borel subalgebra of $g$. In this note, an interesting connection between $Ab(g)$ and the subsets of the Dynkin diagram of $g$ is discussed. We notice that the number of abelian ideals with $k$ generators equals the number of subsets of the Dynkin diagram with $k$ connected components.

  18. Liselotte Jauffred, Marit Sletmoen, Fabian Czerwinski, Lene Oddershede

    Individual colloidal quantum dots can be optically trapped and manipulated by a single infrared laser beam operated at low laser powers. If the absorption spectrum and the emission wavelength of the trapping laser are appropriately chosen, the trapping laser light can act as a source for two-photon excitation of the trapped quantum dot. This eliminates the n

  19. Kamaljit I. Lakhtaria

    Managing network complexity, accommodating greater numbers of subscribers, improving coverage to support data services (e.g. email, video, and music downloads), keeping up to speed with fast-changing technology, and driving maximum value from existing networks - all while reducing CapEX and OpEX and ensuring Quality of Service (QoS) for the network and Quali

  20. I. Bagetakos, E. Brinks, F. Walter, W. J. G. de Blok

    We present an analysis of the properties of HI holes detected in 20 galaxies that are part of "The HI Nearby Galaxy Survey" (THINGS). We detected more than 1000 holes in total in the sampled galaxies. Where they can be measured, their sizes range from about 100 pc (our resolution limit) to about 2 kpc, their expansion velocities range from 4 to 36 km

  21. Oleksandr Tsyplyatyev, Jan von Delft, Daniel Loss

    We present an elementary derivation of the exact solution (Bethe-Ansatz equations) of the Dicke model, using only commutation relations and an informed Ansatz for the structure of its eigenstates.

  22. Jalaluddin Qureshi, Chuan Heng Foh, Jianfei Cai

    Retransmission based on packet acknowledgement (ACK/NAK) is a fundamental error control technique employed in IEEE 802.11-2007 unicast network. However the 802.11-2007 standard falls short of proposing a reliable MAC-level recovery protocol for multicast frames. In this paper we propose a latency and bandwidth efficient coding algorithm based on the principl

  23. Satoshi Yamashita, Tomoya Moriura, Yasuhiro Nakazawa, Hiroyuki Yoshida

    Thermodynamic investigations on volborthite (Cu3V2O7(OH)2 2H2O), which possesses a two-dimensional kagome structure of S-1/2 spins, are presented. The low-temperature heat capacities of volborthite and its Zn analogue compound were measured by the relaxation calorimetry technique between 0.8 and 45 K. The magnetic heat capacity of volborthite is characterize

  24. Koichi Yamawaki

    In contrast to the folklore that Technicolor (TC) is a "Higgsless theory", we shall discuss existence of a composite Higgs boson, Techni-Dilaton (TD), a pseudo-Nambu-Goldstone boson of the scale invariance in the Scale-invariant/Walking/Conformal TC (SWC TC) which generates a large anomalous dimension $γ_m \simeq 1$ in a wide region from the dynamica

  25. Ikuo S. Sogami

    Gauge field theory of a horizontal symmetry of the group G = SU(2) X U(1) is developed so as to generalize the standard model of particle physics. All fermion and scalar fields are assumed to belong to doublets and singlets of the group in high energy regime. Mass matrices with four texture zeros of Dirac and Majorana types are systematically derived. In add

  26. Ulrich Kraehmer, Elmar Wagner

    The fundamental Hochschild cohomology class of the standard Podles quantum sphere is expressed in terms of the spectral triple of Dabrowski and Sitarz by means of a residue formula.

  27. K. Nagashio, T. Nishimura, K. Kita, A. Toriumi

    The contact properties between metal and graphene were examined. The electrical measurement on a multiprobe device with different contact areas revealed that the current flow preferentially entered graphene at the edge of the contact metal. The analysis using the cross-bridge Kelvin structure (CBK) suggested that a transition from the edge conduction to area

  28. Yaser Miaji, Suhaidi Hassan

    In this paper we analytically propose an alternative approach to achieve better fairness in scheduling mechanisms which could provide better quality of service particularly for real time application. Our proposal oppose the allocation of the bandwidth which adopted by all previous scheduling mechanism. It rather adopt the opposition approach be proposing the

  29. Kyle Bradford, Yevgeniy Kovchegov

    We state and prove a generalized adiabatic theorem for Markov chains and provide examples and applications related to Glauber dynamics of Ising model over Z^d/nZ^d. The theorems derived in this paper describe a type of adiabatic dynamics for l^1(R_+^n) norm preserving, time inhomogeneous Markov transformations, while quantum adiabatic theorems deal with l^2(

  30. Naomasa Kitagawa, Takaaki Yokoyama, Shinsuke Imada, Hirohisa Hara

    In order to better understand the possibility of coronal heating by MHD waves, we analyze Fe xii 195.12Å data observed with EUV Imaging Spectrometer (EIS) onboard Hinode. We performed a Fourier analysis of EUV intensity and Doppler velocity time series data in the active region corona. Notable intensity and Doppler velocity oscillations were found for two mo

  31. Charalampos Markakis, Jocelyn S. Read, Masaru Shibata, Koji Uryu

    The properties of neutron star matter above nuclear density are not precisely known. Gravitational waves emitted from binary neutron stars during their late stages of inspiral and merger contain imprints of the neutron-star equation of state. Measuring departures from the point-particle limit of the late inspiral waveform allows one to measure properties of

  32. Huan Tran, N. E. Bonesteel

    A generalized version of the valence-bond Monte Carlo method is used to study ground state properties of the 1+1 dimensional quantum $Q$-state Potts models. For appropriate values of $Q$ these models can be used to describe interacting chains of non-Abelian anyons --- quasiparticle excitations of certain exotic fractional quantum Hall states.

  33. Vladimir Privman, Jian Zhou, Jan Halamek, Evgeny Katz

    We consider a realization of the XOR logic gate in a system involving two competing biocatalytic reactions, for which the logic-1 output is defined by these two processes causing a change in the optically detected signal. A model is developed for describing such systems in an approach suitable for evaluation of the analog noise amplification properties of th

  34. L. Monaco, P. Bonifacio, L. Sbordone, S. Villanova

    A discrepancy has emerged between the cosmic lithium abundance inferred by the WMAP satellite measurement coupled with the prediction of the standard big-bang nucleosynthesis theory, and the constant Li abundance measured in metal-poor halo dwarf stars (the so-called Spite plateau). Several models are being proposed to explain this discrepancy, involving eit

  35. George E. Simion, Gabriele F. Giuliani

    We show that a result equivalent to Overhauser's famous Hartree-Fock instability theorem can be established for the case of a two-dimensional electron gas in the presence of Rashba spin-obit coupling. In this case it is the spatially homogeneous paramagnetic chiral ground state that is shown to be differentially unstable with respect to a certain class o

  36. Mihoko M. Nojiri, Kazuki Sakurai

    Use of inclusive MT2 distribution for sparticle mass determination is discussed. We define new parameters MT2(min) and MT2mod(min), which are a kind of minimum of sub-systerm MT2 values. Their endpoints are less affected by initial state radiations. We demonstrate that both masses of squark and gluino can be extracted from the endpoints of the distributions

  37. Michael D. Seifert

    I discuss the possibility of topological defect solutions in field theories containing a tensor field which spontaneously breaks Lorentz symmetry. I find that for theories of a tensor with rank r <= 5 and for which the vacuum manifold consists of the tensors whose &#34;square&#34; is some constant value, only three types of tensor (vectors, antisymmetric two

  38. Le Zhang, Francesco Miniati, Guenter Sigl

    High energy electrons and positrons from annihilating dark matter can imprint unique angular anisotropies on the diffuse gamma-ray flux by inverse Compton scattering off the interstellar radiation field. We develop a numerical tool to compute gamma-ray emission from such electrons and positrons produced in the smooth host halo and in substructure halos with

  39. Graham D. Kribs, Takemichi Okui, Tuhin S. Roy

    We present a complete, viable model of gravity-mediated supersymmetry breaking that is safe from all flavor constraints. The central new idea is to employ a supersymmetry breaking sector without singlets, but with D-terms comparable to F-terms, causing supersymmetry breaking to be dominantly communicated through U(1)_R-symmetric operators. We construct a vis

  40. Chris S. Yung, Brian H. Moeckly

    Magnesium diboride (MgB2) thin films are a potential alternative to low-temperature superconductors (LTS) due to a higher critical temperature (Tc) of approximately 39 K. The reactive evaporation deposition technique also affords relatively simple growth of MgB2 films on flexible substrates compared to high-temperature superconductors (HTS). We have designed

  41. Heather Matheson, Samar Safi-Harb

    (Abridged) In 1999, Chandra revealed a 150&#34;-radius X-ray halo surrounding the 40&#34;-radius PWN G21.5-0.9. A 2005 imaging study showed that the halo is limb-brightened, and suggested this feature is a candidate for the long-sought SNR shell. We present a spectral analysis of G21.5-0.9, using the longest effective observation to date (578.6 ks with ACIS,

  42. Michael F. Bietenholz, Heather Matheson, Samar Safi-Harb, Crystal Brogan

    We report on sensitive new 1.4-GHz VLA radio observations of the pulsar wind nebula G21.5-0.9, powered by PSR J1833-1034, and its environs. Our observations were targeted at searching for the radio counterpart of the shell-like structure seen surrounding the pulsar wind nebula in X-rays. Some such radio emission might be expected as the ejecta from the <~ 10

  43. Netanel H. Lindner, Gil Refael, Victor Galitski

    Topological phase transitions between a conventional insulator and a state of matter with topological properties have been proposed and observed in mercury telluride - cadmium telluride quantum wells. We show that a topological state can be induced in such a device, initially in the trivial phase, by irradiation with microwave frequencies, without closing th

  44. Serena Bertone, Joop Schaye

    Rest-frame UV emission lines offer the possibility to directly image the gas around high-redshift galaxies with upcoming optical instruments. We use a suite of large, hydrodynamical simulations to predict the nature and detectability of emission lines from the intergalactic medium at 2<z<5. The brightest emission comes from HI Ly-alpha and the strongest meta

  45. S. Piano, R. Grein, C. J. Mellor, K. Vyborny

    We investigate the spin-polarization of the ferromagnetic semiconductor (Ga,Mn)As by point contact Andreev reflection spectroscopy. The conductance spectra are analyzed using a recent theoretical model that accounts for momentum- and spin-dependent scattering at the interface. This allows us to fit the data without resorting, as in the case of the standard s

  46. H. M. Antia, Sarbani Basu

    The minimum of solar cycle 24 is significantly different from most other minima in terms of its duration as well as its abnormally low levels of activity. Using available helioseismic data that cover epochs from the minimum of cycle 23 to now, we study the differences in the nature of the solar rotation between the minima of cycles 23 and 24. We find that th

  47. James M. Cline, Andrew R. Frey, Fang Chen

    We explore dark matter mechanisms that can simultaneously explain the galactic 511 keV gamma rays observed by INTEGRAL/SPI, the DAMA/LIBRA annual modulation, and the excess of low-recoil dark matter candidates observed by CoGeNT. It requires three nearly degenerate states of dark matter in the 4-7 GeV mass range, with splittings respectively of order an MeV

  48. Jessica Goodman, Masahiro Ibe, Arvind Rajaraman, William Shepherd

    We show that colliders can impose strong constraints on models of dark matter, in particular when the dark matter is light. We analyze models where the dark matter is a fermion or scalar interacting with quarks and/or gluons through an effective theory containing higher dimensional operators which represent heavier states that have been integrated out of the

  49. Vincent Corbin, Neil J. Cornish

    Pulsar timing is a promising technique for detecting low frequency sources of gravitational waves. Historically the focus has been on the detection of diffuse stochastic backgrounds, such as those formed from the superposition of weak signals from a population of binary black holes. More recently, attention has turned to members of the binary population that

  50. Osvaldo Chandia

    The ghost for world-sheet reparametrization invariance is not a fundamental field in the pure spinor formalism. It is written as a combination of pure spinor variables which have conformal dimension two and such that it commutes with the BRST operator to give the world-sheet stress tensor. We show that the ghost variable defined in this way is nilpotent sinc

  51. C. P. Shen

    Using a sample of 102 million $\Upsilon(1S)$ events collected with the Belle detector, we report on the first search for charge-parity-even charmonium and charmonium-like states in $\Upsilon(1S)$ radiative decays. No significant $\chi_{cJ}$ or $\eta_c$ signal is observed and 90% C.L. limits on $\BR(\Upsilon(1S)\to \gamma \chi_{c0})<6.5 \times 10^{-4}$, $\BR(

  52. Alexander A. Tsirlin, Ioannis Rousochatzakis, Deepa Kasinathan, Oleg Janson

    We derive and investigate the microscopic model of the quantum magnet BiCu2PO6 using band structure calculations, magnetic susceptibility and high-field magnetization measurements, as well as ED and DMRG techniques. The resulting quasi-one-dimensional spin model is a two-leg AFM ladder with frustrating next-nearest-neighbor couplings along the legs. The indi

  53. A. Yazdani, P. Jeffrey

    In this work, water distribution systems are regarded as large sparse planar graphs with complex network characteristics and the relationship between important topological features of the network (i.e. structural robustness and loop redundancy) and system resilience, viewed as the antonym to structural vulnerability, are assessed. Deterministic techniques fr

  54. V. G. Bagrov, S. P. Gavrilov, D. M. Gitman, D. P. Meira Filho

    A new approach to constructing coherent states (CS) and semiclassical states (SS) in magnetic-solenoid field is proposed. The main idea is based on the fact that the AB solenoid breaks the translational symmetry in the xy-plane, this has a topological effect such that there appear two types of trajectories which embrace and do not embrace the solenoid. Due t

  55. Amir Bennatan, Shlomo Shamai, A. Robert Calderbank

    We provide a rigorous mathematical analysis of two communication strategies: soft decode-and-forward (soft-DF) for relay channels, and soft partial interference-cancelation (soft-IC) for interference channels. Both strategies involve soft estimation, which assists the decoding process. We consider LDPC codes, not because of their practical benefits, but beca

  56. Tetsuro Saito, Seiichiro Onari, Hiroshi Kontani

    We study the pairing mechanism in iron pnictide superconductors based on the five-orbital Hubbard-Holstein model. Due to Fe-ion oscillations, the s-wave superconducting (SC) state without sign reversal (s_{++}-wave state) is induced by orbital fluctuations by using realistic model parameters. The virtue of the present theory is that the famous empirical rela

  57. David S. Berman, Malcolm J. Perry

    We reformulate the Hamiltonian form of bosonic eleven dimensional supergravity in terms of an object that unifies the three-form and the metric. For the case of four spatial dimensions, the duality group is manifest and the metric and C-field are on an equal footing even though no dimensional reduction is required for our results to hold. One may also descri

  58. Sanjib Sabhapandit

    The statistics of records for a time series generated by a continuous time random walk is studied, and found to be independent of the details of the jump length distribution, as long as the latter is continuous and symmetric. However, the statistics depend crucially on the nature of the waiting time distribution. The probability of finding M records within a

  59. Jochen Brüning, Franz W. Kamber, Ken Richardson

    In this paper we prove a formula for the analytic index of a basic Dirac-type operator on a Riemannian foliation, solving a problem that has been open for many years. We also consider more general indices given by twisting the basic Dirac operator by a representation of the orthogonal group. The formula is a sum of integrals over blowups of the strata of the

  60. Hisham Sati

    Studying the M-branes leads us naturally to new structures that we call Membrane-, Membrane^c-, String^K(Z,3)- and Fivebrane^K(Z,4)-structures, which we show can also have twisted counterparts. We study some of their basic properties, highlight analogies with structures associated with lower levels of the Whitehead tower of the orthogonal group, and demonstr

  61. A. Bongiovanni, I. Oteo, J. Cepa, A. M. Perez Garcia

    Ly-alpha emitters (LAEs) are seen everywhere in the redshift domain from local to z~7. Far-infrared (FIR) counterparts of LAEs at different epochs could provide direct clues on dust content, extinction, and spectral energy distribution (SED) for these galaxies. We search for FIR counterparts of LAEs that are optically detected in the GOODS-North field at red

  62. Abhijit Majumder, Berndt Müller

    Finite temperature lattice simulations of quantum chromodynamics (QCD) are sensitive to the hadronic mass spectrum for temperatures below the &#34;critical&#34; temperature T_c ~ 160 MeV. We show that a recent precision determination of the QCD trace anomaly shows evidence for the existence of a large number of hadron states beyond those known from experimen

  63. Robert Treger

    We prove a conjecture of Shafarevich about universal coverings of projective manifolds provided the fundamental group is residually finite.

  64. Wolfgang Kreitmeier, Tamas Linder

    We consider optimal scalar quantization with $r$th power distortion and constrained Rényi entropy of order $α$. For sources with an absolutely continuous distribution the high rate asymptotics of the quantizer distortion has long been known for $α=0$ (fixed-rate quantization) and $\al pha=1$ (entropy-constrained quantization). For a large class of absolutely

  65. Frank Wilczek

    The BCS theory injected two powerful ideas into the collective consciousness of theoretical physics: pairing and spontaneous symmetry breaking. In the 50 years since the seminal work of Bardeen, Cooper, and Schrieffer, those ideas have found important use in areas quite remote from the stem application to metallic superconductivity. This is a brief and eclec

  66. Jasper Hasenkamp, Jörn Kersten

    Many extensions of the Standard Model predict super-weakly interacting particles, which typically have to decay before Big Bang Nucleosynthesis (BBN). The entropy produced in the decays may help to reconcile thermal leptogenesis and BBN in scenarios with gravitino dark matter, which is usually difficult due to late decays of the next-to-lightest supersymmetr

  67. Aneta Siemiginowska, D. J. Burke, Thomas L. Aldcroft, D. M. Worrall

    We present the first results from a new, deep (200ks) Chandra observation of the X-ray luminous galaxy cluster surrounding the powerful (L ~10^47 erg/s), high-redshift (z=1.067), compact-steep-spectrum radio-loud quasar 3C186. The diffuse X-ray emission from the cluster has a roughly ellipsoidal shape and extends out to radii of at least ~60 arcsec (~500 kpc

  68. S. Riordan, S. Abrahamyan, B. Craver, A. Kelleher

    The electric form factor of the neutron was determined from studies of the reaction He3(e,e&#39;n)pp in quasi-elastic kinematics in Hall A at Jefferson Lab. Longitudinally polarized electrons were scattered off a polarized target in which the nuclear polarization was oriented perpendicular to the momentum transfer. The scattered electrons were detected in a

  69. Lars Winther Christensen, David A. Jorgensen, Hamidreza Rahmati, Janet Striuli

    Let R be a commutative noetherian local ring that is not Gorenstein. It is known that the category of totally reflexive modules over R is representation infinite, provided that it contains a non-free module. The main goal of this paper is to understand how complex the category of totally reflexive modules can be in this situation. Local rings (R,m) with m^3=

  70. Sally Cockburn, Yonghyun Song

    A geometric graph is a simple graph G together with a straight line drawing of G in the plane with the vertices in general position. Two geometric realizations of a simple graph are geo-isomorphic if there is a vertex bijection between them that preserves vertex adjacencies and non-adjacencies, as well as edge crossings and non-crossings. A natural extension

  71. Yanwei Ma, Lei Wang, Yanpeng Qi, Zhaoshun Gao

    The development of the PIT fabrication process of iron pnictide superconducting wires and tapes has been carried out in order to enhance their transport properties. Silver was found to be the best sheath material, since no reaction layer was observed between the silver sheath and the superconducting core. The grain connectivity of iron pnictide wires and tap

  72. Rok Zitko, Oliver Bodensiek, Thomas Pruschke

    We study the magnetic anisotropy effects on the localized sub-gap excitations induced by quantum impurities coupled to a superconducting host. We establish the ground-state phase diagrams for single-channel and two-channel high-spin Kondo impurities; they unveil surprising complexity that results from the (multi-stage) Kondo screening in competition with the

  73. J. R. Fergusson, D. M. Regan, E. P. S. Shellard

    We present an efficient separable approach to the estimation and reconstruction of the bispectrum and the trispectrum from observational (or simulated) large scale structure data. This is developed from general CMB (poly-)spectra methods which exploit the fact that the bispectrum and trispectrum in the literature can be represented by a separable mode expans

  74. Ohad Perry, Ward Whitt

    In previous papers we developed a deterministic fluid approximation for an overloaded Markovian queueing system having two customer classes and two service pools, known in the call-center literature as the X model. The system uses the fixed-queue-ratio-with-thresholds (FQR-T) control, which we proposed in a recent paper as a way for one service system to hel

  75. Jessica Baker, Arshad Kudrolli

    Motivated by the relation between particle shape and packing, we measure the volume fraction $ϕ$ occupied by the Platonic solids which are a class of polyhedron with congruent sides, vertices and dihedral angles. Tetrahedron, cube, octahedron, dodecahedron, and icosahedron shaped plastic dice were fluidized or mechanically vibrated to find stable random loos

  76. Florian Wolfgramm, Alessandro Cere, Federica A. Beduini, Ana Predojevic

    We demonstrate a light-shot-noise-limited magnetometer based on the Faraday effect in a hot unpolarized ensemble of rubidium atoms. By using off-resonant, polarization-squeezed probe light, we improve the sensitivity of the magnetometer by 3.2 dB. The technique could improve the sensitivity of the most advanced magnetometers and quantum nondemolition measure

  77. Lorenzo Iorio

    We analytically work out the cumulative, i.e. averaged over one orbital revolution, time variations of the radial velocity v_r of a typical S star orbiting the Supermassive Black Hole (SBH) hosted by the Galactic Center (GC) in Sgr A* caused by several dynamical effects. They are the general relativistic gravitoelectromagnetic (GEM) fields of the SBH, its qu

  78. R. Rosenfelder

    Several path integral representations for the $T$-matrix in nonrelativistic potential scattering are given which produce the complete Born series when expanded to all orders and the eikonal approximation if the quantum fluctuations are suppressed. They are obtained with the help of &#34;phantom&#34; degrees of freedom which take away explicit phases that div

  79. Elizaveta Levina, Roman Vershynin

    A classical approach to accurately estimating the covariance matrix Σof a p-variate normal distribution is to draw a sample of size n > p and form a sample covariance matrix. However, many modern applications operate with much smaller sample sizes, thus calling for estimation guarantees in the regime n << p. We show that a sample of size n = O(m log^6 p) is

  80. Daniel Lemire

    Iterated hash functions process strings recursively, one character at a time. At each iteration, they compute a new hash value from the preceding hash value and the next character. We prove that iterated hashing can be pairwise independent, but never 3-wise independent. We show that it can be almost universal over strings much longer than the number of hash

  81. Andriy Kostyuk, Andrei Korol, Andrey Solov&#39;yov, Walter Greiner

    A new Monte Carlo code for the simulation of the channeling of ultrarelativistic charged projectiles in single crystals is presented. A detailed description of the underlying physical model and the computation algorithm is given. First results obtained with the code for the channeling of 855 MeV electrons in Silicon crystal are presented. The dechanneling le

  82. Harinder Pal, M. S. Santhanam

    We study the classical and quantum dynamics of periodically kicked particles placed initially within an open double-barrier structure. This system does not obey the Kolmogorov-Arnold-Moser (KAM) theorem and displays chaotic dynamics. The phase space features induced by non-KAM nature of the system leads to dynamical features such as the non-equilibrium stead

  83. Valery Rubakov, Andrey Vlasov

    We give an account, at non-expert and quantitative level, of physics behind the CMB temperature anisotropy and polarization and their peculiar features. We discuss, in particular, how cosmological parameters are determined from the CMB measurements and their combinations with other observations. We emphasize that CMB is the major source of information on the

  84. Sven Herrmann, Vincent Moulton

    A k-dissimilarity map on a finite set X is a function D : X \choose k \rightarrow R assigning a real value to each subset of X with cardinality k, k \geq 2. Such functions, also sometimes known as k-way dissimilarities, k-way distances, or k-semimetrics, are of interest in many areas of mathematics, computer science and classification theory, especially 2-di

  85. Laurent Bakri

    We give an upper bound for the $(n-1)$-dimensional Hausdorff measure of the critical set of eigenfunctions of the Laplacian on compact analytic Riemannian manifolds. This is the analog of H. Donnely and C. Fefferman result on nodal set of eigenfunctions.

  86. Kenichi Shimizu

    Let $F, G: \mathcal{I} \to \mathcal{C}$ be strong monoidal functors from a skeletally small monoidal category $\mathcal{I}$ to a tensor category $\mathcal{C}$ over an algebraically closed field $k$. The set $Nat(F, G)$ of natural transformations $F \to G$ is naturally a vector space over $k$. We show that the set $Nat_\otimes(F, G)$ of monoidal natural trans

  87. Tian-Hai Zeng

    The interaction between two parts in a compound quantum system may be reconsidered more completely than before and some new understandings and conclusions different from current quantum mechanics are obtained, including the conservation law in the evolution in an isolated quantum system, new understandings of duality of particle and wave and the superpositio

  88. Lijing Shao, Yunhua Zhang, Bo-Qiang Ma

    A new and simple statistical approach is performed to calculate the parton distribution functions (PDFs) of the nucleon in terms of light-front kinematic variables. Analytic expressions of x-dependent PDFs are obtained in the whole x region. And thereafter, we treat the temperature T as a parameter of the atomic number A to explain the nuclear EMC effect in

  89. Jacob Scheuer, Andrey A. Sukhorukov, Yuri S. Kivshar

    We propose and analyze an on-chip all-optical dynamical tuning scheme for coupled nonlinear resonators employing a single control beam injected in parallel with a signal beam. We show that nonlinear Kerr response can be used to dynamically switch the spectral properties between "dark-state" and electromagnetically-induced transparency configurations. Such sc

  90. M. Tamburini, F. Pegoraro, A. Di Piazza, C. H. Keitel

    Radiation reaction (RR) effects on the acceleration of a thin plasma foil by a superintense laser pulse in the radiation pressure dominated regime are investigated theoretically. A simple suitable approximation of the Landau-Lifshitz equation for the RR force and a novel leapfrog pusher for its inclusion in particle-in-cell simulations are provided. Simulati

  91. C. Di Franco, D. Ballester

    Bellman&#39;s optimality principle has been of enormous importance in the development of whole branches of applied mathematics, computer science, optimal control theory, economics, decision making, and classical physics. Examples are numerous: dynamic programming, Markov chains, stochastic dynamics, calculus of variations, and the brachistochrone problem. He

  92. Michel Rumin

    Let $A$ be a self-adjoint operator acting over a space $X$ endowed with a partition. We give lower bounds on the energy of a mixed state $\rho$ from its distribution in the partition and the spectral density of $A$. These bounds improve with the refinement of the partition, and generalize inequalities by Li-Yau and Lieb--Thirring for the Laplacian in $\R^n$.

  93. Alex V Berka

    Space is a circuit oriented, spatial programming language designed to exploit the massive parallelism available in a novel formal model of computation called the Synchronic A-Ram, and physically related FPGA and reconfigurable architectures. Space expresses variable grained MIMD parallelism, is modular, strictly typed, and deterministic. Barring operations a

  94. A. I. Ahmadov, R. M. Burjaliyev

    In this article, we investigate the next-to-leading order contribution of the higher-twist Feynman diagrams to the large-$p_T$ inclusive pion production cross section in proton-proton collisions and present the general formulae for the higher-twist differential cross sections in the case of the running coupling and frozen coupling approaches. We compared the

  95. D. N. Aristov

    We consider the Y-junction, connecting three quantum wires, in the scattering states formalism. In the absence of fermionic interaction we analyze the restrictions on the values of conductance matrix, imposed by the unitarity of scattering S-matrix. Using the combination of numerical and analytical results, we describe the four-dimensional body of values of

  96. Ninan Sajeeth Philip

    A learning algorithm based on primary school teaching and learning is presented. The methodology is to continuously evaluate a student and to give them training on the examples for which they repeatedly fail, until, they can correctly answer all types of questions. This incremental learning procedure produces better learning curves by demanding the student t

  97. Y. -H. Chen, S. Varma, T. M. Antonsen, H. M. Milchberg

    We present direct time- and space- resolved measurements of the electron density of femtosecond laser pulse-induced plasma filaments. The dominant nonlinearity responsible for extended atmospheric filaments is shown to be field-induced rotation of air molecules.

  98. Jin Hu, Zheng Chang, Gengkai Hu

    By idealizing a general mapping as a series of local affine ones, we derive approximately transformed material parameters necessary to control solid elastic waves within classical elasticity theory. The transformed elastic moduli are symmetric, and can be used with Navier&#39;s equation to manipulate elastic waves. It is shown numerically that the method can

  99. Avik Dutt, Sayan Kar

    Quantum mechanical tunneling across smooth double barrier potentials modeled using Gaussian functions, is analyzed numerically and by using the WKB approximation. The transmission probability, resonances as a function of incident particle energy, and their dependence on the barrier parameters are obtained for various cases. We also discuss the tunneling time

  100. Andrew C. Thomas

    I examine the consequences of modelling contagious influence in a social network with incomplete edge information, namely in the situation where each individual may name a limited number of friends, so that extra outbound ties are censored. In particular, I consider a prototypical time series configuration where a property of the &#34;ego&#34; is affected in