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February 2009 arXiv papers — page 23

Showing 2,2012,300 of 4,929 papers

  1. NV Drenska, R Faccini, AD Polosa

    We investigate on exotic tetraquark hadrons of the kind [cs][cbar sbar] by computing their spectrum and decay modes within a constituent diquark-antidiquark model. We also compare these predictions with the present experimental knowledge.

  2. Guangyong Xu, G. D. Gu, M. Hucker, B. Fauque

    Much of what we know about the electronic states of high-temperature superconductors is due to photoemission and scanning tunneling spectroscopy studies of the compound Bi2212. The demonstration of well-defined quasiparticles in the superconducting state has encouraged many theorists to apply the conventional theory of metals, Fermi-liquid theory, to the cup

  3. R. Ciftci, A. K. Ciftci, S. Sultansoy

    Single resonant productions of the fourth standard model generation charged lepton via anomalous interactions at gamma e colliders based on future linear e^+ e^- colliders with 500 GeV and 1 TeV center of mass energies are studied. Signatures of $γe\to \ell_4\to eγ$ and $γe\to \ell_4\to eZ$ anomalous processes followed by the hadronic and leptonic decay of t

  4. Ryan J. Foley, Ryan Chornock, Alexei V. Filippenko, Mohan Ganeshalingam

    We present ultraviolet, optical, and near-infrared photometry as well as optical spectra of the peculiar supernova (SN) 2008ha. SN 2008ha had a very low peak luminosity, reaching only M_V = -14.2 mag, and low line velocities of only ~2000 km/s near maximum brightness, indicating a very small kinetic energy per unit mass of ejecta. Spectroscopically, SN 2008h

  5. Emily Levesque

    Red supergiants (RSGs) are a He-burning phase in the evolution of moderately massive stars (10-25 solar masses). For many years, the assumed physical properties of these stars placed them at odds with the predictions of evolutionary theory. We have recently determined new effective temperatures and luminosities for the RSG populations of galaxies with a fact

  6. Ali Pourmohammad, Seyed Mohammad Ahadi

    This paper has been withdrawn by the author ali pourmohammad.

  7. Carles Badenes, Jason Harris, Dennis Zaritsky, Jose Luis Prieto

    We use the star formation history map of the Large Magellanic Cloud to study the sites of the eight smallest (and presumably youngest) supernova remnants in the Cloud: SN 1987A, N158A, N49, and N63A (core collapse remnants), 0509-67.5, 0519-69.0, N103B, and DEM L71 (Type Ia remnants). The local star formation histories provide unique insights into the nature

  8. Ali Pourmohammad, Seyed Mohammad Ahadi

    This paper has been withdrawn by the author ali pourmohammad.

  9. Marcelo R. Ubriaco

    We propose entropy functions based on fractional calculus. We show that this new entropy has the same properties than the Shannon entropy except additivity, therefore making this entropy non-extensive. We show that this entropy function satisfies the Lesche and thermodynamic stability criteria.

  10. D. Hsieh, Y. Xia, L. Wray, D. Qian

    A topologically ordered material is characterized by a rare quantum organization of electrons that evades the conventional spontaneously broken symmetry based classification of condensed matter. Exotic spin transport phenomena such as the dissipationless quantum spin Hall effect have been speculated to originate from a novel topological order whose identific

  11. C. F. Berger, Z. Bern, L. J. Dixon, F. Febres Cordero

    We report on the first next-to-leading order QCD computation of W + 3-jet production in hadronic collisions including all partonic subprocesses. We compare the results with CDF data from the Tevatron, and find excellent agreement. The renormalization and factorization scale dependence is reduced substantially compared to leading-order calculations. The requi

  12. Tomoyuki Yamakami

    Pseudorandomness has played a central role in modern cryptography, finding theoretical and practical applications to various fields of computer science. A function that generates pseudorandom strings from shorter but truly random seeds is known as a pseudorandom generator. Our generators are designed to fool languages (or equivalently, Boolean-valued functio

  13. Edward Ott, Thomas M. Antonsen

    It is shown, under weak conditions, that the dynamical evolution of an important class of large systems of globally coupled, heterogeneous frequency, phase oscillators is, in an appropriate physical sense, time-asymptotically attracted toward a reduced manifold of system states. This manifold, which is invariant under the system evolution, was previously kno

  14. Henry Gillow-Wiles, Tevian Dray

    We show that any 3-component octonionic vector which is purely imaginary, but not quaternionic, is an eigenvector of a 6-parameter family of Hermitian octonionic matrices, with imaginary eigenvalue equal to the associator of its elements.

  15. A. Morozov, Sh. Shakirov

    We show that partition functions of various matrix models can be obtained by acting on elementary functions with exponents of W-operators. A number of illustrations is given, including the Gaussian Hermitian matrix model, Hermitian model in external field and the Hurwitz-Kontsevitch model, for which we suggest an elegant matrix-model representation. In all t

  16. Caroline Champenois

    This tutorial introduces the dynamics of charged particles in a radiofrequency trap in a very general manner to point out the differences between the dynamics in a quadrupole and in a multipole trap. When dense samples are trapped, the dynamics is modified by the Coulomb repulsion between ions. To take into account this repulsion, we propose to use a method,

  17. Simone Mercuri

    A general argument provides the motivation to consider the Barbero--Immirzi parameter as a field. The specific form of the geometrical effective action allows to relate the value of the Barbero--Immirzi parameter to other quantum ambiguities through the analog of the Peccei--Quinn mechanism.

  18. Sergei Alexandrov

    We present some results on instanton corrections to the hypermultiplet moduli space in Calabi-Yau compactifications of Type II string theories. Previously, using twistor methods, only a class of D-instantons (D2-instantons wrapping A-cycles) was incorporated exactly and the rest was treated only linearly. We go beyond the linear approximation and give a set

  19. Weiqiang Wang, Lei Zhao

    The modular representation theory of the queer Lie superalgebra q(n) over characteristic p>2 is developed. We obtain a criterion for the irreducibility of baby Verma modules with semisimple p-characters and a criterion for the semisimplicity of the corresponding reduced enveloping algebras. A (2p)-power divisibility of dimensions of q(n)-modules with nilpote

  20. Nicolas Goze, Elisabeth Remm

    We define a ternary product and more generally a (2k+1)-ary product on the vector space T^p_q(E) of tensors of type (p, q) that is contravariant of order p, covariant of order q and total order (p+q). This product is totally associative up to a permutation s_k of order k (we call this property a s_k-totally associativity). When p=2 and q=1, we obtain a (2k+1

  21. Nima Mirbakhsh, Arman Didandeh

    Classification of some objects in classes of concepts is an essential and even breathtaking task in many applications. A solution is discussed here based on Multi-Agent systems. A kernel of some expert agents in several classes is to consult a central agent decide among the classification problem of a certain object. This kernel is moderated with the center

  22. John M. Losecco

    Muons produced via the $\pi \to \mu \nu_{\mu}$ decay are in a coherent superposition of energy states because the $\nu_{\mu}$ is not a mass eigenstate. This presents an opportunity to access neutrino mixing parameters via muon decay. The oscillation period is long compared to the muon lifetime which presents some experimental challenges.

  23. Jean-Francois Dufaux

    It has recently been shown that specific non-perturbative effects may lead to an explosive decay of flat direction condensates in supersymmetric theories. We confirm explicitly the efficiency of this process with lattice simulations: after few rotations of the condensates in their complex plane, most of their energy is quickly converted into inhomogeneous fl

  24. Sebastian Jaimungal, Alex Kreinin, Angelo Valov

    The first passage time problem for Brownian motions hitting a barrier has been extensively studied in the literature. In particular, many incarnations of integral equations which link the density of the hitting time to the equation for the barrier itself have appeared. Most interestingly, Peskir(2002b) demonstrates that a master integral equation can be used

  25. Rossella Bartolo, Anna Maria Candela, Erasmo Caponio

    In this paper we obtain an existence theorem for normal geodesics joining two given submanifolds in a globally hyperbolic stationary spacetime. The proof is based on both variational and geometric arguments involving the causal structure of the spacetime, the completeness of suitable Finsler metrics associated to it and some basic properties of a submersion.

  26. Sharanya Sur, Axel Brandenburg

    The generation of mean magnetic fields is studied for a simple non-helical flow where a net cross helicity of either sign can emerge. This flow, which is also known as the Archontis flow, is a generalization of the Arnold--Beltrami--Childress flow, but with the cosine terms omitted. The presence of cross helicity leads to a mean-field dynamo effect that is k

  27. Pier Giovanni Bissiri, Stephen G. Walker

    We provide a reason for Bayesian updating, in the Bernoulli case, even when it is assumed that observations are independent and identically distributed with a fixed but unknown parameter $θ_0$. The motivation relies on the use of loss functions and asymptotics. Such a justification is important due to the recent interest and focus on Bayesian consistency whi

  28. Ling Hei Yeung, Manwai Yuen

    This article is the continued version of the analytical solutions for the pressureless Navier-Stokes equations with density-dependent viscosity in "M.W. Yuen, Analyitcal Solutions to the Navier-Stokes Equations, J. Math. Phys., 49 (2008) No. 11, 113102, 10pp". We are able to extend the similar solutions structure to the case with pressure under some

  29. Marie-Noëlle Célérier

    In the framework of the scale relativity theory, the chaotic behavior in time only of a number of macroscopic systems corresponds to motion in a space with geodesics of fractal dimension 2 and leads to its representation by a Schrödinger-like equation acting in the macroscopic domain. The fluid interpretation of such a Schrödinger equation yields Euler and N

  30. A. Hernando, D. Puigdomenech, D. Villuendas, C. Vesperinas

    We present a thermodynamic formulation for scale-invariant systems based on the principle of extreme information. We create an analogy between these systems and the well-known thermodynamics of gases and fluids, and study as a compelling case the non-interacting system -the scale-free ideal gas- presenting some empirical evidences of electoral results, city

  31. J. R. Kristiansen, G. La Vacca, L. P. L. Colombo, R. Mainini

    We consider cosmological models with dynamical dark energy (dDE) coupled to cold dark matter (CDM), while simultaneously allowing neutrinos to be massive. Using a MCMC approach, we compare these models with a wide range of cosmological data sets. We find a strong correlation between this coupling strength and the neutrino mass. This correlation persists when

  32. Erasmo Recami, Michel Zamboni-Rached

    In the FIRST PART we present simple introductions to gaussian and Bessel waves, and to the Localized Waves (LW), pulses or beams, showing the important properties of the latter, and their applications whenever a role is played by a wave-equation (electromagnetism, optics, acoustics, seismology, geophysics, gravitation, elementary particle physics,...). The F

  33. Osvaldo Chandia

    In this note we study the preservation of the classical pure spinor BRST constraints under super T-duality transformations. We also determine the invariance of the one-loop conformal invariance and of the local gauge and Lorentz anomalies under the super T-dualities.

  34. Shilpam Sharma, A. Bharathi, Sharat Chandra, Raghavendra Reddy

    The occurrence of bulk superconductivity at ~22 K is reported in polycrystalline samples of BaFe2-xRuxAs2 for nominal Ru content in the range of x=0.75 to 1.125. A systematic suppression of the spin density wave transition temperature (TSDW) precedes the appearance of superconductivity in the system. A phase diagram is proposed based on the measured TSDW and

  35. Massimo Boninsegni

    Extensive Monte Carlo simulations of bulk liquid para-hydrogen at a temperature T=16.5 K have been carried out using the continuous-space Worm Algorithm. Results for the momentum distribution, as well as for the kinetic energy per particle and the pair correlation function are reported. The static equilibrium thermodynamic properties of this system can be ge

  36. Sebastiano Bernuzzi, Luca Baiotti, Giovanni Corvino, Roberto De Pietri

    We compare different gravitational-wave extraction methods used in three-dimensional nonlinear simulations against linear simulations of perturbations of spherical spacetimes with matter. We present results from fully general-relativistic simulations of a system composed by an oscillating and non-rotating star emitting gravitational radiation. Results about

  37. Teodor Banica, Roland Vergnioux

    The half-liberated orthogonal group $O_n^*$ appears as intermediate quantum group between the orthogonal group $O_n$, and its free version $O_n^+$. We discuss here its basic algebraic properties, and we classify its irreducible representations. The classification of representations is done by using a certain twisting-type relation between $O_n^*$ and $U_n$,

  38. Vinicius Bordalo, Henri Plana, Eduardo Telles

    We present a study of the kinematic properties of the ionized gas in the dominant giant HII region of the well known HII galaxy: II Zw 40. High spatial and spectral resolution spectroscopy has been obtained using IFU mode on the GMOS instrument at Gemini-North telescope. We have used a set of kinematics diagnostic diagrams, such as the intensity vs. velocity

  39. Anna Trevisan, Massimo D'Isidoro, Olivier Talagrand

    A key a priori information used in 4DVar is the knowledge of the system's evolution equations. In this paper we propose a method for taking full advantage of the knowledge of the system's dynamical instabilities in order to improve the quality of the analysis. We present an algorithm, four-dimensional variational assimilation in the unstable subspace

  40. C. Bogdanos

    We discuss a method of calculating the various scalar densities encountered in Lovelock theory which relies on diagrammatic, instead of algebraic manipulations. Taking advantage of the known symmetric and antisymmetric properties of the Riemann tensor which appears in the Lovelock densities, we map every quadratic or higher contraction into a corresponding p

  41. M. E. Tasgin, M. O. Oktel, L. You, O. E. Mustecaplioglu

    We discover an inherent mechanism for entanglement swap associated with sequential superradiance from an atomic Bose-Einstein condensate. Based on careful examinations with both analytical and numerical approaches, we conclude that as a result of the swap mechanism, Einstein-Podolsky-Rosen (EPR)-type quantum correlations can be detected among the scattered l

  42. Pasquale Dario Serpico, Dan Hooper

    In this article, we review the prospects for the Fermi satellite (formerly known as GLAST) to detect gamma rays from dark matter annihilations in the Central Region of the Milky Way, in particular on the light of the recent astrophysical observations and discoveries of Imaging Atmospheric Cherenkov Telescopes. While the existence of significant backgrounds i

  43. G. Grunberg, V. Ravindran

    We check against exact finite order three-loop results for the non-singlet F_2 and F_3 structure functions the validity of a class of momentum space ansaetze for threshold resummation at the next-to-leading order in 1-x, which generalize results previously obtained in the large-β_0 limit. We find that the ansaetze do not work exactly, pointing towards an obs

  44. Ralf Hofmann

    Based on SU(2) Yang-Mills thermodynamics we interprete Aracde2's and the results of earlier radio-surveys on low-frequency CMB line temperatures as a phase-boundary effect. We explain the excess at low frequencies by evanescent, nonthermal photon fields of the CMB whose intensity is nulled by that of Planck distributed calibrator photons. The CMB baseline te

  45. Jianhui Dai, Jian-Xin Zhu, Qimiao Si

    Some of the high Tc iron pnictides contain magnetic rare-earth elements, raising the question of how the existence and tunability of a d-electron antiferromagnetic order influences the heavy fermion behavior of the f-moments. With CeOFeP and CeOFeAs in mind as prototypes, we derive an extended Anderson lattice model appropriate for these quaternary systems.

  46. Marlos O. Ribas, Gilberto M. Kremer

    In this work the accelerated-decelerated transition in a primordial Universe is investigated by using the dynamics of fermion fields within the context of Einstein-Cartan theory, where apart from the curvature the space-time is also described by a torsion field. The model analyzed here has only a fermion field as the source of the gravitational field. The te

  47. Walter Bergweiler

    For 0 < c < 1/e the Julia set of f(z) = c exp(z) is an uncountable union of pairwise disjoint simple curves tending to infinity [Devaney and Krych 1984], the Hausdorff dimension of this set is two [McMullen 1987], but the set of curves without endpoints has Hausdorff dimension one [Karpinska 1999]. We show that these results have three-dimensional analogues

  48. Marcello Baldo, Camille Ducoin

    We study the possible collective plasma modes which can affect neutron-star thermodynamics and different elementary processes in the baryonic density range between nuclear saturation ($ρ_0$) and $3ρ_0$. In this region, the expected constituents of neutron-star matter are mainly neutrons, protons, electrons and muons ($npeμ$ matter), under the constraint of b

  49. Arik Yochelis, Moshe Sheintuch

    This paper has been withdrawn by the author(s), due to acceptance of the paper for publication in Physical Chemistry Chemical Physics.

  50. J. T. Mościcki, F. Brochu, J. Ebke, U. Egede

    In this paper, we present the computational task-management tool Ganga, which allows for the specification, submission, bookkeeping and post-processing of computational tasks on a wide set of distributed resources. Ganga has been developed to solve a problem increasingly common in scientific projects, which is that researchers must regularly switch between d

  51. Satoshi Nozawa, Yasuharu Kohyama

    Starting from a covariant formalism of the Sunyaev-Zeldovich effect for the thermal and non-thermal distributions, we derive the frequency redistribution function identical to Wright&#39;s method assuming the smallness of the photon energy (in the Thomson limit). We also derive the redistribution function in the covariant formalism in the Thomson limit. We s

  52. Andrey V. Timofeev, Meri Helle, Matthias Meschke, Mikko Möttönen

    We demonstrate quantum limited electronic refrigeration of a metallic island in a low temperature micro-circuit. We show that matching the impedance of the circuit enables refrigeration at a distance, of about 50 um in our case, through superconducting leads with a cooling power determined by the quantum of thermal conductance. In a reference sample with a m

  53. M. Gonzales, Z. Kuznetsova, A. Nersessian, F. Toppan

    We propose to use the second Hopf map for the reduction (via SU(2) group action) of the eight-dimensional N=8 supersymmetric mechanics to five-dimensional supersymmetric systems specified by the presence of an SU(2) Yang monopole. For our purpose we develop the relevant Lagrangian reduction procedure. The reduced system is characterized by its invariance und

  54. Z. H. Zhang, H. R. A. Jones, D. J. Pinfield, R. S. Pokorny

    We selected brown dwarf candidates from the seventh Data Release of the Sloan Digital Sky Survey (SDSS DR7) with new photometric selectioncriteria based on a parameteriaztion of well-known L and T dwarfs. Then we confirmed their status with SDSS spectra. The candidates without SDSS spectra are cross matched in the Two Micron All Sky Survey (2MASS) and the Fo

  55. Lance Fortnow, Jack H. Lutz, Elvira Mayordomo

    This paper investigates the existence of inseparable disjoint pairs of NP languages and related strong hypotheses in computational complexity. Our main theorem says that, if NP does not have measure 0 in EXP, then there exist disjoint pairs of NP languages that are P-inseparable, in fact TIME(2^(n^k))-inseparable. We also relate these conditions to strong hy

  56. Vitorio A. De Lorenci

    The energy-momentum tensor coming from one-parameter effective Yang- Mills theory is here used to describe the matter-energy content of the homogeneous and isotropic Friedmann cosmology in its early stages. The behavior of all solutions is examined. Particularly, it is shown that only solutions corresponding to an open model allow the universe to evolve into

  57. M. Ben Shalom, C. W. Tai, Y. Lereah, M. Sachs

    The resistivity as a function of temperature, magnetic field and its orientation for atomically flat SrTiO3\LaAlO3 interfaces with carrier densities of ~3*10^13 cm^-2 is reported. At low magnetic fields superconductivity is observed below 130mK. The temperature dependence of the high field magnetoresistance and its strong anisotropy suggest possible magnetic

  58. A. G. Akeroyd, F. Mahmoudi

    The decays D(s)+- -> mu+- nu and D(s)+- -> tau+- nu have traditionally been used to measure the D(s)+- meson decay constant f_D(s). Recent measurements at CLEO-c and the B factories suggest a branching ratio for both decays somewhat higher than the Standard Model prediction using f_D(s) from unquenched lattice calculations. The charged Higgs boson (H+-) in t

  59. C. Pascual Garcia, F. Giazotto

    We report the successful fabrication of planar V/Cu/V mesoscopic Josephson weak-links of different size, and the analysis of their low-temperature behavior. The shorter junctions exhibit critical currents of several tens of microA at 350 mK, while Josephson coupling persists up to ~2.7 K. Good agreement is obtained by comparing the measured switching current

  60. A. M. Stephens, Z. W. E. Evans

    Estimates of the quantum accuracy threshold often tacitly assume that it is possible to interact arbitrary pairs of qubits in a quantum computer with a failure rate that is independent of the distance between them. None of the many physical systems that are candidates for quantum computing possess this property. Here we study the performance of a concatenate

  61. J. Danon, I. T. Vink, F. H. L. Koppens, K. C. Nowack

    We observe multiple stable states of nuclear polarization in a double quantum dot under conditions of electron spin resonance. The stable states can be understood within an elaborated theoretical rate equation model for the polarization in each of the dots, in the limit of strong driving. This model also captures unusual features of the data, such as fast sw

  62. Vladimir V. Gorin

    To simulate the influence of pendulum effect in hollow cathode configuration on a current-voltage characteristic it is proposed to consider a plane glow discharge in one-dimensional space configuration with two plane parallel cathodes and one plane anode in the middle. A pendulum effect could be switched on or off, with consideration for the anode to be tran

  63. Kai Zhao, Zhuxia Li, Xizhen Wu, Zhixiang Zhao

    Mass parameters for the relative and neck motions in fusion reactions of symmetric systems $^{90}$Zr+$^{90}$Zr, $^{110}$Pd+$^{110}$Pd, and $^{138}$Ba+$^{138}$Ba are studied by means of a microscopic transport model. The shape of the nuclear system is determined by an equi-density surface obtained from the density distribution of the system. The relative and

  64. Valentin Blickle, Jakob Mehl, Clemens Bechinger

    We study the relaxation of a single colloidal sphere which is periodically driven between two nonequilibrium steady states. Experimentally, this is achieved by driving the particle along a toroidal trap imposed by scanned optical tweezers. We find that the relaxation time after which the probability distributions have been relaxed is identical to that obtain

  65. Markus Kuba

    In this note we consider ternary trees naturally embedded in the plane in a deterministic way such that the root has position zero, or in other words label zero, and the children of a node with position $j$ have positions $j-1$, $j$, and $j+1$, for all $j\in\Z$. We derive the generating function of ternary trees where all nodes have labels which are less or

  66. C. Lehner, M. Ohtani, J. J. M. Verbaarschot, T. Wettig

    We study the effect of topology for a random matrix model of QCD at nonzero imaginary chemical potential or nonzero temperature. Non-universal fluctuations of Dirac eigenvalues lead to normalization factors that contribute to the $\theta$-dependence of the partition function. These normalization factors have to be canceled in order to reproduce the $\theta$-

  67. Tobias Fritz

    This note gives generators and relations for the strict monoidal category of probabilistic maps on finite cardinals (i.e., stochastic matrices).

  68. Adam Bzdak

    The forward-backward multiplicity correlation strength is calculated for arbitrary nucleus-nucleus collision in the framework of the wounded nucleon model. Discussion of our results in the context of the recent STAR data in Au+Au collisions at sqrt{s}=200 GeV is presented. It is suggested that the observed (i) growth of the correlation coefficient with centr

  69. Chuan-Hung Chen

    Inspired by the recent observation of the $D^0-\bar D^0$ mixing, we explore the effects of colored scalars on the $\Delta C=2$ process in diquark models. As an illustration, we investigate the diquarks with the quantum numbers of (6, 1, 1/3) and (6, 1, 4/3) under $SU(3)_C\times SU(2)_L\times U(1)_Y$ gauge symmetries, which contribute to the process at one-lo

  70. El Houcein El Abdalaoui

    It is shown that there exists an $α$-rigid transformation with $α$ less or equal to $\frac12$ whose spectrum has Lebesgue component. This answers the question raised by Klemes and Reinhold in \cite{Klemes-Reinhold}. We exhibit also a large class of $α$-rigid transformations with singular spectrum.

  71. Pravabati Chingangbam, Qing-Guo Huang

    We study the axion-type curvaton model, with emphasis on the large field regime where analytic results are very difficult to obtain. We evaluate the tensor-scalar ratio $r$ using WMAP normalization and the non-linearity parameters $f_{NL}$ and $g_{NL}$ by solving the equations numerically using the $δN$ formalism. We compare them with results for the curvato

  72. S. K. Samaddar, J. N. De

    The nuclear thermodynamic observables like the temperature, volume and the specific heat as obtained from isotopic ratios in hot disassembled nuclear matter are examined in the light of the S-matrix approach to the nuclear equation of state. The values of the observables, as extracted without inclusion of scattering effects are found to be modified appreciab

  73. Hongbo Cheng

    The Casimir effect for parallel plates within the frame of five-dimensional Randall-Sundrum model with two branes is reexamined. We argue that the nature of Casimir force is repulsive if the distance between the plates is not extremely tiny, which is not consistent with the experimental phenomena. We also point out that the estimation of the separation betwe

  74. James R. Bogan

    We suggest discovery targets for the Higgs boson, dark matter, and quantum gravity mass scales, motivated by the Dirac equation for the electron in deSitter space, and a sixth-order constraint between the electron QED parameters and the cosmological constant. We go on to show that this constraint can be viewed as a structural parameter of the electron, and l

  75. R. N. C. Pfeifer, T. A. Nieminen, N. R. Heckenberg, H. Rubinsztein-Dunlop

    There exist two popular energy-momentum tensors for an electromagnetic wave in a dielectric medium. The Abraham expression is robust to experimental verification but more mathematically demanding, while the Minkowski expression is the foundation of a number of simplifications commonly found within the literature, including the relative refractive index trans

  76. L. L. Kiss, J. D. Monnier, T. R. Bedding, P. Tuthill

    We have obtained H-band interferometric observations of three galactic red supergiant stars using the MIRC instrument on the CHARA array. The targets include AZ Cyg, a field RSG and two members of the Per OB1 association, RS Per and T Per. We find evidence of departures from circular symmetry in all cases, which can be modelled with the presence of hotspots.

  77. Adam J. Burgasser, Josh Bloom, Kelle Cruz, Michael Cushing

    This White Paper to the National Academy of Sciences Astro2010 Decadal Review Committee highlights cross-disciplinary science opportunities over the next decade with cold brown dwarfs, sources defined here as having photospheric temperatures less than ~1000 K.

  78. Michael Hill, Tyler Lawson

    We compute the homotopy groups of spectra associated by a theorem of Lurie to the Shimura curves of discriminants 6, 10, and 14, beginning with a computation of integral rings of automorphic forms on these curves. As an application, we find that a generalized truncated Brown-Peterson spectrum BP<2> is an E_\infty ring spectrum at the prime 3.

  79. Kaustubh Agashe

    We propose new mechanisms for ameliorating the constraints on the Kaluza-Klein (KK) mass scale from charged lepton flavor violation in the framework of the Standard Model (SM) fields propagating in a warped extra dimension, especially in models accounting for neutrino data. These mechanisms utilize the extended five-dimensional (5D) electroweak gauge symmetr

  80. Satoru Odake, Ryu Sasaki

    In one-dimensional quantum mechanics, or the Sturm-Liouville theory, Crum&#39;s theorem describes the relationship between the original and the associated Hamiltonian systems, which are iso-spectral except for the lowest energy state. Its counterpart in `discrete&#39; quantum mechanics is formulated algebraically, elucidating the basic structure of the discr

  81. Gregory Arone, Kathryn Lesh

    We explore connections between our earlier work, in which we constructed spectra that interpolate between bu and HZ, and earlier work of Kuhn and Priddy on the Whitehead conjecture and of Rognes on the stable rank filtration in algebraic K-theory. We construct a &#34;chain complex of spectra&#34; that is a bu-analogue of an auxiliary complex used by Kuhn-Pri

  82. Evan N. Kirby, Puragra Guhathakurta, James S. Bullock, Anna Frebel

    The hierarchical theory of galaxy formation rests on the idea that smaller galactic structures merge to form the galaxies that we see today. The past decade has provided remarkable observational support for this scenario, driven in part by advances in spectroscopic instrumentation. Multi-object spectroscopy enabled the discovery of kinematically cold substru

  83. Adam S. Sikora

    We study properties of irreducible and completely reducible representations of finitely generated groups Gamma into reductive algebraic groups G in in the context of the geometric invariant theory of the G-action on Hom(Gamma,G) by conjugation. In particular, we study properties of character varieties, X_G(Gamma)=Hom(Gamma,G)//G. We describe the tangent spac

  84. Feng Qi, Bai-Ni Guo

    In this paper, by a concise and elementary approach, we sharpen and generalize Shafer&#39;s inequality for the arc sine function, and some known results are extended and generalized.

  85. Fionn Murtagh, Michael Spagat, Jorge A. Restrepo

    We first pursue the study of how hierarchy provides a well-adapted tool for the analysis of change. Then, using a time sequence-constrained hierarchical clustering, we develop the practical aspects of a new approach to wavelet regression. This provides a new way to link hierarchical relationships in a multivariate time series data set with external signals.

  86. Dax Enshan Koh

    There has been spectacular progress in the field of quantum information in recent decades. The development of this field highlights the importance of the role of entanglement in quantum computing, quantum teleportation and quantum cryptography. These notes serve to provide a gentle introduction to the entanglement of bipartite states. In these notes, we intr

  87. Parviz Ghavamian, John C. Raymond, William P. Blair, Knox S. Long

    We present mid-infrared (5-40 micron) spectra of shocked ejecta in the Galactic oxygen-rich supernova remnant G292.0+1.8, acquired with the IRS spectrograph on board the Spitzer Space Telescope. The observations targeted two positions within the brightest oxygen-rich feature in G292.0+1.8. Emission lines of [Ne II] 12.8, [Ne III] 15.5, 36.0, [Ne V] 24.3 and

  88. E. M. Hankiewicz, G. Vignale

    In this review, we describe in detail two important spin-transport phenomena: the extrinsic spin-Hall effect (coming from spin-orbit interactions between electrons and impurities) and the spin-Coulomb drag. The interplay of these two phenomena is analyzed. In particular, we discuss the influence of scattering between electrons with opposite spins on the spin

  89. Z. H. Zhang, R. S. Pokorny, H. R. A. Jones, D. J. Pinfield

    Aims. We try to identify ultra-cool dwarfs from the seventh Data Release of the Sloan Digital Sky Survey (SDSS DR7) with SDSS i-z and r-z colors. We also obtain proper motion data from SDSS, 2MASS, and UKIDSS and improve spectral typing from SDSS and 2MASS photometric colors. Methods. We selected ultra-cool dwarf candidates from the SDSS DR7 with new photome

  90. Guido Altarelli

    I present a concise review of where we stand in particle physics today. First, I will discuss the status of the Standard Model, its open problems and the expected answers from the LHC. Then I will briefly review the avenues for New Physics that can be revealed by the LHC.

  91. Dru B. Renner, Xu Feng

    We calculate the vacuum polarization tensor for pion masses from 480 MeV to 270 MeV using dynamical twisted mass fermions at a lattice spacing of 0.086 fm. We analyze the form of the polarization tensor on the lattice using the symmetries of twisted QCD and we study both finite size effects and lattice artifacts at a pion mass of 310 MeV. Results for the low

  92. Chandra Chekuri, Nitish Korula

    Given an undirected graph G=(V,E) and subset of terminals T \subseteq V, the element-connectivity of two terminals u,v \in T is the maximum number of u-v paths that are pairwise disjoint in both edges and non-terminals V \setminus T (the paths need not be disjoint in terminals). Element-connectivity is more general than edge-connectivity and less general tha

  93. R. C. Reis, J. M. Miller, A. C. Fabian

    We report on the detection of a thermal-disk component from the stellar-mass black hole binary XTE J1118+480 in the canonical low/hard state. The presence of a thermal component with a temperature of approximately 0.21keV in the Chandra spectra of XTE J1118+480 is found at more than the 14 sigma confidence level. Based on this evidence we argue that the accr

  94. Isaac Shlosman

    We review some general properties of assembling galactic dark matter (DM) halos which have a direct effect on the baryon dynamics. Specifically, we focus on the mutual dynamical feedback between baryons and DM which influence disk formation and evolution, by comparing models with and without baryons evolved from identical initial conditions. Baryons are foun

  95. K. Mattsson, Mark H. Carpenter

    Block-to-block interface interpolation operators are constructed for several common high-order finite difference discretizations. In contrast to conventional interpolation operators, these new interpolation operators maintain the strict stability, accuracy and conservation of the base scheme even when nonconforming grids or dissimilar operators are used in a

  96. M. A. Despósito, A. D. Viñales

    A theoretical framework for analyzing stochastic data from single-particle tracking in complex or viscoelastic materials and under the influence of a trapping potential is presented. Starting from a generalized Langevin equation we found explicit expressions for the two-time dynamics of the tracer particle. The mean square displacement and the velocity autoc

  97. Kilian Raschel

    Nearest neighbor random walks in the quarter plane that are absorbed when reaching the boundary are studied. The cases of positive and zero drift are considered. Absorption probabilities at a given time and at a given site are made explicit. The following asymptotics for these random walks starting from a given point $(n_0,m_0)$ are computed : that of probab

  98. M. D. Lehnert, N. P. H. Nesvadba, L. Le Tiran, P. Di Matteo

    We analyze the physical conditions in the interstellar gas of 11 actively star-forming galaxies at z~2, based on integral-field spectroscopy from the ESO-VLT and HST/NICMOS imaging. We concentrate on the high H-alpha surface brightnesses, large line widths, line ratios and the clumpy nature of these galaxies. We show that photoionization calculations and emi

  99. Gary Bernstein, Dragan Huterer

    We study the sensitivity of weak lensing surveys to the effects of catastrophic redshift errors - cases where the true redshift is misestimated by a significant amount. To compute the biases in cosmological parameters, we adopt an efficient linearized analysis where the redshift errors are directly related to shifts in the weak lensing convergence power spec

  100. Ria Johnson, Trevor J. Ponman, Alexis Finoguenov

    (abridged) We present a statistical analysis of 28 nearby galaxy groups from the Two-Dimensional XMM-Newton Group Survey (2dXGS). We focus on entropy and the role of feedback, dividing the sample into cool core (CC) and non cool core (NCC) systems, the first time the latter have been studied in detail in the group regime. The coolest groups have steeper entr