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December 2007 arXiv papers — page 23

Showing 2,2012,300 of 4,627 papers

  1. CLAS Collaboration, P. E. Bosted, R. Fersch

    The (W,Q2)-dependence of the ratio of inclusive electron scattering cross sections for 15N/12C was determined in the kinematic range 0.8<W<2 GeV and 0.2<Q2<1 GeV2 using 2.285 GeV electrons and the CLAS detector at Jefferson Lab. The ratios exhibit only slight resonance structure, in agreement with a simple phenomenological model and an extrapolation of DIS r

  2. Tamara Broderick, Miroslav Dudik, Gasper Tkacik, Robert E. Schapire

    Recent work has shown that probabilistic models based on pairwise interactions-in the simplest case, the Ising model-provide surprisingly accurate descriptions of experiments on real biological networks ranging from neurons to genes. Finding these models requires us to solve an inverse problem: given experimentally measured expectation values, what are the p

  3. Sean Fitzpatrick

    Given an elliptic action of a compact Lie group $G$ on a co-oriented contact manifold $(M,E)$ one obtains two naturally associated objects: A $G$-transversally elliptic operator $\dirac$, and an equivariant differential form with generalised coefficients $\mathcal{J}(E,X)$ defined in terms of a choice of contact form on $M$. We explain how the form $\mathcal

  4. Vitaly Vanchurin

    We develop an analytical model to study the production spectrum of loops in the cosmic string network. In the scaling regime, we find two different scales corresponding to large (one order below horizon) and small (few orders below horizon) loops. The very small (tiny) loops at the gravitational back reaction scale are absent, and thus, our model has no ultr

  5. George Lowther

    In this paper we look at the properties of limits of a sequence of real valued time inhomogeneous diffusions. When convergence is only in the sense of finite-dimensional distributions then the limit does not have to be a diffusion. However, we show that as long as the drift terms satisfy a Lipschitz condition and the limit is continuous in probability, then

  6. Nikolay G. Moshchevitin

    For $α, β, δ\in [0,1], α+β= 1 $ we consider sets $$ {\rm BAD}^* (α, β;δ) = \left\{ξ= (ξ_1,ξ_2) \in [0,1]^2: ,\inf_{p\in \mathbb{N}} \max \{(p\log(p+1))^α||pξ_1||, (p\log (p+1))^β||pξ_2||\} \ge δ\right\}. $$ We prove that for different $(α_1,β_1), (α_2,β_2), α_1 +β_1 = α_2 +β_2 = 1 $ and $δ$ small enough $$ {\rm BAD}^* (α_1, β_1 ;δ) \bigcap {\rm BAD}^* (α_2,

  7. Henriette Elvang, Maria J. Rodriguez

    We present detailed physics analyses of two different 4+1-dimensional asymptotically flat vacuum black hole solutions with spin in two independent planes: the doubly spinning black ring and the bicycling black ring system (&#34;bi-rings&#34;). The latter is a new solution describing two concentric orthogonal rotating black rings which we construct using the

  8. Peter R. W. McNamara, Stephanie van Willigenburg

    There is considerable current interest in determining when the difference of two skew Schur functions is Schur positive. We consider the posets that result from ordering skew diagrams according to Schur positivity, before focussing on the convex subposets corresponding to ribbons. While the general solution for ribbon Schur functions seems out of reach at pr

  9. Damien Roy

    We provide an upper bound on the uniform exponent of approximation to a triple (xi, xi^2, xi^3) by rational numbers with the same denominator, valid for any transcendental real number xi. This upper bound refines a previous result of Davenport and Schmidt. As a consequence, we get a sharper lower bound on the exponent of approximation of such a number xi by

  10. Mark Heinz

    Precise determination of heavy flavor production cross-sections at LHC energies will be of primary importance. The produced heavy quarks are expected to be sensitive probes of parton energy loss in the medium formed in heavy-ion collisions. Through the measurement of charm and bottom suppression in Pb + Pb with respect to p + p, we hope to obtain insight int

  11. Rodion Neigovzen, C. Rodó, Gerardo Adesso, A. Sanpera

    We demonstrate that the Byzantine Agreement (detectable broadcast) is also solvable in the continuous-variable scenario with multipartite entangled Gaussian states and Gaussian operations (homodyne detection). Within this scheme we find that Byzantine Agreement requires a minimum amount of entanglement in the multipartite states used in order to achieve a so

  12. R. Marangell, R. Rimanyi

    Maps between manifolds $M^m\to N^{m+\ell}$ ($\ell>0$) have multiple points, and more generally, multisingularities. The closure of the set of points where the map has a particular multisingularity is called the multisingularity locus. There are universal relations among the cohomology classes represented by multisingularity loci, and the characteristic class

  13. Martin Mann, Guido Tack, Sebastian Will

    We describe decomposition during search (DDS), an integration of And/Or tree search into propagation-based constraint solvers. The presented search algorithm dynamically decomposes sub-problems of a constraint satisfaction problem into independent partial problems, avoiding redundant work. The paper discusses how DDS interacts with key features that make pro

  14. Cristiano Germani, Arabella Schelpe

    We construct actions of higher spin fields interacting with gravity on AdS_5 backgrounds such that the Compton scattering amplitudes of the interaction are tree-level unitary. We then consider higher-spin fields in the Randall-Sundrum scenario. There, in the fermionic case, we construct a tree-level unitary action of higher spin fields interacting with brane

  15. Fathi Namouni, Massimiliano Guzzo, Elena Lega

    An accelerated logarithmic potential models the mean motion of stars in a flat rotation curve galaxy that sustains a wind system. For stars outside the galactic wind launching region, the asymmetric removal of linear momentum by the wind is seen as a perturbing acceleration superimposed onto the galactic potential. We study the integrability of stellar motio

  16. Jaeyoon Cho, Dimitris G. Angelakis, Sougato Bose

    We propose a scheme to generate two-photon, two-atom, or atom-photon entangledstates with a coupled system of two cavities. In our scheme, two cavity photonsare exchanged by the direct inter-cavity coupling, while atoms in the cavitiessimply play the role of generating and probing them. By virtue of the highefficiency of atomic state measurement, this method

  17. S. Ahmad, H. Honkanen, S. Liuti, S. K. Taneja

    Following a previous detailed study of unpolarized generalized parton distribution functions in the non-singlet sector, and at zero values of the skewness variable, $ζ$, we propose a physically motivated parametrization that is valid at $ζ\neq 0$. Our method makes use of information from the nucleon form factor data, from deep inelastuc scattering parton dis

  18. Ludovic Dan Lemle

    Consider the Schrödinger operator ${\cal A}=-\fracΔ{2}+V$ acting on space $C_0^\infty(D)$, where $D$ is an open domain in $\R^d$. The main purpose of this paper is to present the $L^\infty(D,dx)$-uniqueness for Schrödinger operators which is equivalent to the $L^1(D,dx)$-uniqueness of weak solutions of the heat diffusion equation associated to the operator $

  19. Paul McGuirk, Gary Shiu, Kathryn M. Zurek

    We study the effect of the infrared (IR) geometry on the phenomenology of warped extra dimensions with gauge and fermion fields in the bulk. We focus in particular on a "mass gap" metric which is AdS in the ultraviolet, but asymptotes to flat space in the IR, breaking conformal symmetry. These metrics can be dialed to approximate well the geometries arising

  20. Tudor Stanescu, Brandon Anderson, Victor Galitski

    We consider a many-body system of pseudo-spin-1/2 bosons with spin-orbit interactions, which couple the momentum and the internal pseudo-spin degree of freedom created by spatially varying laser fields. The corresponding single- particle spectrum is generally anisotropic and contains two degenerate minima at finite momenta. At low temperatures, the many-body

  21. T. Barreiro, B. de Carlos, E. J. Copeland, N. J. Nunes

    We study the effect of thermal corrections on the evolution of moduli in effective Supergravity models. This is motivated by previous results in the literature suggesting that these corrections could alter and, even, erase the presence of a minimum in the zero temperature potential, something that would have disastrous consequences in these particular models

  22. Matthew Fayers

    We prove a new `runner removal theorem&#39; for $q$-decomposition numbers of the level 1 Fock space of type $A^{(1)}_{e-1}$, generalising earlier theorems of James--Mathas and the author. By combining this with another theorem relating to the Mullineux map, we show that the problem of finding all $q$-decomposition numbers indexed by partitions of a given wei

  23. G. Susinder Rajan, B. Sundar Rajan

    In this paper, collocated and distributed space-time block codes (DSTBCs) which admit multi-group maximum likelihood (ML) decoding are studied. First the collocated case is considered and the problem of constructing space-time block codes (STBCs) which optimally tradeoff rate and ML decoding complexity is posed. Recently, sufficient conditions for multi-grou

  24. Tevatron New Phenomena, Higgs Working group

    We combine results from CDF and D0 searches for a standard model Higgs boson (H) in ppbar collisions at the Fermilab Tevatron at sqrt{s}=1.96 TeV. With 1.0-1.9 fb-1 of data collected at CDF, and 0.9-1.7 fb-1 at D0, the 95% C.L. upper limits on Higgs production are a factor of 6.2 (1.4) higher than the SM cross section for a Higgs mass of m_Higgs = 115 (160)

  25. Kent Slinker

    In this paper I introduce a model which allows one to prove Goldbachs hypothesis. The model is produced by studying Goldbach partitions as displayed by an inverted mirror image of all the primes up to some even number equal to the last prime plus three. The bottom half of the model is then moved to the right in steps of two which exhibit the Goldbach partiti

  26. B. Holdom

    Nonperturbative and lattice methods indicate that Gribov copies modify the infrared behavior of gauge theories and cause a suppression of gluon propagation. We investigate whether this can be implemented in a modified perturbation theory. The minimal modification proceeds via a nonlocal generalization of the Fadeev-Popov ghost that automatically decouples fr

  27. A. E. Gutman, A. G. Kusraev, S. S. Kutateladze

    In 1977 Anthony Wickstead raised the question of the conditions for all band preserving linear operators to be order bounded in a vector lattice. This article overviews the main ideas and results on the Wickstead problem and its variations, focusing primarily on the case of band preserving operators in a universally complete vector lattice.

  28. Ali N. Khorramian, S. Atashbar Tehrani

    In this paper we use the experimental data to obtain the polarized parton distribution functions (PPDFs) in the LO and NLO approximations. The analysis is based on the Jacobi polynomials expansion of the polarized structure function (PSF). Our calculations for polarized parton distribution functions based on the Jacobi polynomials method are in good agreemen

  29. Jason H. Steffen, Octavio Valenzuela

    We present, using a novel technique, a study of the angular distribution of satellite galaxies around a sample of isolated, blue host galaxies selected from the sixth data release of the Sloan Digital Sky Survey. As a complement to previous studies we subdivide the sample of galaxies into bins of differing inclination and use the systematic differences that

  30. Changjian Fu, Pin Liu

    We show that a tilting module over the endomorphism algebra of a cluster-tilting object in a 2-Calabi-Yau triangulated category lifts to a cluster-tilting object in this 2-Calabi-Yau triangulated category. This generalizes a recent work of D. Smith for cluster categories.

  31. Yves Gallot, Pieter Moree

    Let $Φ_n(x)$ denote the $n$th cyclotomic polynomial. In 1968 Sister Marion Beiter conjectured that $a_n(k)$, the coefficient of $x^k$ in $Φ_n(x)$, satisfies $|a_n(k)|\le (p+1)/2$ in case $n=pqr$ with $p<q<r$ primes (in this case $Φ_n(x)$ is said to be ternary). Since then several results towards establishing her conjecture have been proved (for example $|a_n

  32. B. F. Kostenko, J. Pribish, M. Z. Yuriev

    Theory of computer calculations strongly depends on the nature of elements the computer is made of. Quantum interference allows to formulate the Shor factorization algorithm turned out to be more effective than any one written for classical computers. Similarly, quantum wave packet reduction allows to devise the Grover search algorithm which outperforms any

  33. J. S. Lee, M. Carena, J. Ellis, A. Pilaftsis

    We describe the Fortran code CPsuperH2.}, which contains several improvements and extensions of its predecessor CPsuperH. It implements improved calculations of the Higgs-boson pole masses, notably a full treatment of the 4 times 4 neutral Higgs propagator matrix including the Goldstone boson and a more complete treatment of threshold effects in self-energie

  34. R. Frederix, F. Maltoni

    We explore in detail the physics potential of a measurement of the ttbar invariant mass distribution. First, we assess the accuracy of the best available predictions for this observable and find that in the low invariant mass region, the shape is very well predicted and could be used to perform a top mass measurement. Second, we study the effects of a heavy

  35. Ansgar Reiners

    The bottom of the main sequence hosts objects with fundamentally different properties. At masses of about 0.3 M$_{\odot}$, stars become fully convective and at about 0.08 M$_{\odot}$ the hydrogen-burning main sequence ends; less massive objects are brown dwarfs. While stars and brown dwarfs experience very different evolutions, their inner structure has rela

  36. Bin Chen, Yi Wang, Wei Xue

    We calculate the contribution of the fluctuations with the thermal origin to the inflationary nonGaussianity. We find that even a small component of radiation can lead to a large nonGaussianity. We show that this thermal nonGaussianity always has positive $f_{\rm NL}$. We illustrate our result in the chain inflation model and the very weakly dissipative warm

  37. Robert L. Benedetto, Dragos Ghioca, Par Kurlberg, Thomas J. Tucker

    We prove a special case of a dynamical analogue of the classical Mordell-Lang conjecture. In particular, let $ϕ$ be a rational function with no superattracting periodic points other than exceptional points. If the coefficients of $ϕ$ are algebraic, we show that the orbit of a point outside the union of proper preperiodic subvarieties of $(\bP^1)^g$ has only

  38. J. L. Jaramillo, J. A. Valiente Kroon, E. Gourgoulhon

    This article reviews some aspects in the current relationship between mathematical and numerical General Relativity. Focus is placed on the description of isolated systems, with a particular emphasis on recent developments in the study of black holes. Ideas concerning asymptotic flatness, the initial value problem, the constraint equations, evolution formali

  39. D. I. Dimitrov, A. Milchev, K. Binder

    When a very thin capillary is inserted into a liquid, the liquid is sucked into it: this imbibition process is controlled by a balance of capillary and drag forces, which are hard to quantify experimentally, in particularly considering flow on the nanoscale. By computer experiments using a generic coarse-grained model, it is shown that an analysis of imbibit

  40. Mahender Singh

    Let $X$ be a finitistic space with its rational cohomology isomorphic to that of the wedge sum $P^2(n)\vee S^{3n} $ or $S^{n} \vee S^{2n}\vee S^{3n}$. We study continuous $\mathbb{S}^1$ actions on $X$ and determine the possible fixed point sets up to rational cohomology depending on whether or not $X$ is totally non-homologous to zero in $X_{\mathbb{S}^1}$ i

  41. Makoto Sakurai

    Some time ago, the chiral algebra theory of Beilinson-Drinfeld was expected to play a central role in the convergence of divergence in mathematical physics of superstring theory for quantization of gauge theory and gravity. Naively, this algebra plays an important role in a holomorphic conformal field theory with a non-negative integer graded conformal dimen

  42. Michael Schmied, Robert Sims, Gerald Teschl

    We consider standard subordinacy theory for general Sturm--Liouville operators and give criteria when boundedness of solutions implies that no subordinate solutions exist. As applications, we prove a Weidmann-type result for general Sturm--Liouville operators and investigate the absolutely continuous spectrum of radially symmetric quantum trees.

  43. Patricio Gaete, Euro Spallucci

    Features of screening and confinement are studied for a non-Abelian gauge theory with a mixture of pseudoscalar and scalar coupling, in the case where a constant chromo-electric, or chromo-magnetic, strength expectation value is present. Our discussion is carried out using the gauge-invariant but path-dependent variables formalism. We explicitly show that th

  44. Jens Mueller, Steffen Wirth, Stephan von Molnar

    Arrays of Fe-nanoparticles grown by STM-assited CVD have been placed on top of a narrow stripe of Py. The magnetic coupling between the nanoparticles and the underlying Py film results in distinct negative jumps of the Py magnetoresistance. The switching of the magnetization orientation of individual particles is clearly reflected in the Py magnetoresistance

  45. Caroline Chaux, Laurent Duval, Amel Benazza-Benyahia, Jean-Christophe Pesquet

    The use of multicomponent images has become widespread with the improvement of multisensor systems having increased spatial and spectral resolutions. However, the observed images are often corrupted by an additive Gaussian noise. In this paper, we are interested in multichannel image denoising based on a multiscale representation of the images. A multivariat

  46. Jean-Francois Dayen, Ather Mahmood, Dmitry S. Golubev, Isabelle Roch-Jeune

    In this Letter, we present the patterning, exfoliation and micromanipulation of thin graphitic discs which are subsequently connected and patterned into sub-100nm wide ribbons with a resist-free process using Focused Ion Beam (FIB) lithography and deposition. The electronic transport properties of the double side-gated nanoribbons are then investigated down

  47. T. Delahaye, R. Lineros, F. Donato, N. Fornengo

    Indirect detection signals from dark matter annihilation are studied in the positron channel. We discuss in detail the positron propagation inside the galactic medium: we present novel solutions of the diffusion and propagation equations and we focus on the determination of the astrophysical uncertainties which affect the positron dark matter signal. We find

  48. Thomas Oikonomou

    We reconsider the Boltzmann-Gibbs statistical ensemble in thermodynamics using the multinomial coefficient approach. We show that an ensemble is defined by the determination of four statistical quantities, the element probabilities $p_i$, the configuration probabilities $P_j$, the entropy $S$ and the extremum constraints (EC). This distinction is of central

  49. Valerio Scarani

    The local and non-local contents of non-local probability distributions are studied using the approach of Elitzur, Popescu and Rohrlich [Phys. Lett. A \textbf{162}, 25 (1992)]. This work focuses on distributions that can be obtained by single-copy von Neumann measurements on bipartite quantum systems. For pure two-qubit states Psi(theta)=cos(theta)|00>+sin(t

  50. J. Messud, P. M. Dinh, P. -G. Reinhard, E. Suraud

    We discuss an extension of time-dependent density-functional theory by a self-interaction correction (SIC). A strictly variational formulation is given taking care of the necessary constraints. A manageable and transparent propagation scheme using two sets of wavefunctions is proposed and applied to laser excitation with subsequent ionization of a dimer mole

  51. Georg Hager, Thomas Zeiser, Gerhard Wellein

    Processor and system architectures that feature multiple memory controllers are prone to show bottlenecks and erratic performance numbers on codes with regular access patterns. Although such effects are well known in the form of cache thrashing and aliasing conflicts, they become more severe when memory access is involved. Using the new Sun UltraSPARC T2 pro

  52. Stephen L. Olsen

    The Belle experiment's recent results on CP violation in B meson decays are summarized.

  53. T. Ono, S. Doi, Y. Hori, I. Ichinose

    We study the three-dimensional (3D) compact U(1) lattice gauge theory coupled with $N$-flavor Higgs fields by means of the Monte Carlo simulations. This model is relevant to multi-component superconductors, antiferromagnetic spin systems in easy plane, inflational cosmology, etc. It is known that there is no phase transition in the N=1 model. For N=2, we fou

  54. Wei Huang, Zhaohui Wei

    We show how to explicitly construct an $O(nd)$ size and constant quantum depth circuit which encodes any given $n$-qubit stabilizer code with $d$ generators. Our construction is derived using the graphic description for stabilizer codes and the one-way quantum computation model. Our result demonstrates how to use cluster states as scalable resources for many

  55. Tsung-Wen Yeh

    In this paper, the twist-3 two parton corrections in charmless $B\to PP$ decays are shown to be factorizable under the QCD factorization approach. The factorizability of the twist-3 two parton corrections is constructed on the following findings. Under the energetic meson limit, the pseudoscalar distribution amplitude for a light pseudoscalar meson is allowe

  56. Alex Degtyarev

    We compute the fundamental group of the complement of each irreducible sextic of weight eight or nine (in a sense, the largest groups for irreducible sextics), as well as of 169 of their derivatives (both of and not of torus type). We also give a detailed geometric description of sextics of weight eight and nine and of their moduli spaces and compute their A

  57. Mitsutoshi Fujita

    Small perturbations of a black brane are interpreted as small deviations from thermodynamic equilibrium in a dual theory with the AdS/CFT correspondence. In this paper, we calculate hydrodynamics of the dual Yang-Mills theory in the gravity side using membrane paradigm. This method is different from the usual AdS/CFT correspondence and evaluate classical sol

  58. Yu Shi, Yue-Liang Wu

    Quantum teleportation using neutral pseudoscalar mesons shows novel connections between particle physics and quantum information. The projection basis, which is crucial in the teleportation process, is determined by the conservation laws of particle physics, and is different from the Bell basis, as in the usual case. Here we show that one can verify the tele

  59. B. Julia-Diaz, T. -S. H. Lee, A. Matsuyama, T. Sato

    The electromagnetic pion production reactions are investigated within the dynamical coupled-channels model developed in {\bf Physics Reports, 439, 193 (2007)}. The meson-baryon channels included in this study are $γN$, $πN$, $ηN$, and the $πΔ$, $ρN$ and $σN$ resonant components of the $ππN$ channel. With the hadronic parameters of the model determined in a r

  60. Gong-Bo Zhao, Dragan Huterer, Xinmin Zhang

    We use the recent type Ia supernova, cosmic microwave background and large-scale structure data to shed light on the temporal evolution of the dark energy equation of state $w(z)$ out to redshift one. We constrain the most flexible parametrization of dark energy to date, and include the dark energy perturbations consistently throughout. Interpreting our resu

  61. Alexis Diaz-Torres

    A self-contained Fortran-90 program based on a classical trajectory model with stochastic breakup is presented, which should be a powerful tool for quantifying complete and incomplete fusion, and breakup in reactions induced by weakly-bound two-body projectiles near the Coulomb barrier. The code calculates complete and incomplete fusion cross sections and th

  62. Salvatore Capozziello, Shinji Tsujikawa

    We study constraints on f(R) dark energy models from solar system experiments combined with experiments on the violation of equivalence principle. When the mass of an equivalent scalar field degree of freedom is heavy in a region with high density, a spherically symmetric body has a thin-shell so that an effective coupling of the fifth force is suppressed th

  63. Paras Naik, Liming Zhang, Norman Lowrey

    We present several recent analyses of Dalitz plots from the CLEO-c experiment, including published and preliminary analyses of D+ to pi- pi+ pi+, D+ to K- pi+ pi+, and D0 to K0_{S,L} pi+ pi- decays. More information on these analyses can be found in References [1-3]. New preliminary analyses we present include a search for CP asymmetry in D+ to K+ K- pi+ dec

  64. Jonathan Barrett, Matthew Leifer

    We prove a de Finetti theorem for exchangeable sequences of states on test spaces, where a test space is a generalization of the sample space of classical probability theory and the Hilbert space of quantum theory. The standard classical and quantum de Finetti theorems are obtained as special cases. By working in a test space framework, the common features t

  65. Richard Lieu

    Concordance cosmology points to a Universe of zero mean curvature, due to the inflation mechanism which occurred soon after the Big Bang, while along a relatively small number of lower redshift light paths where lensing events are observed, space is positively curved. How do we know that global geometry and topology are robust rather than in a state of chaos

  66. Yang Liu, Jon Sauer, Robert Dutton

    A numerical study within the framework of the Poisson-Nernst-Planck equations is conducted to investigate electrostatic screening of charged bio-molecules within synthetic pores having diameters of at least 10 Debye lengths. We show that with external biases, the bio-molecule charge is only partially screened due to the presence of electrodiffusion current f

  67. Graeme Smith, John A. Smolin

    We study extensions of a quantum channel whose one-way capacities are described by a single-letter formula. This provides a simple technique for generating powerful upper bounds on the capacities of a general quantum channel. We apply this technique to two qubit channels of particular interest--the depolarizing channel and the channel with independent phase

  68. Zhenning Kong, Edmund M. Yeh

    Previous studies of connectivity in wireless networks have focused on undirected geometric graphs. More sophisticated models such as Signal-to-Interference-and-Noise-Ratio (SINR) model, however, usually leads to directed graphs. In this paper, we study percolation processes in wireless networks modelled by directed SINR graphs. We first investigate interfere

  69. Jeff Andrews, Nihar Jindal, Martin Haenggi, Randy Berry

    The subject of this paper is the long-standing open problem of developing a general capacity theory for wireless networks, particularly a theory capable of describing the fundamental performance limits of mobile ad hoc networks (MANETs). A MANET is a peer-to-peer network with no pre-existing infrastructure. MANETs are the most general wireless networks, with

  70. Shiliang Li, Zahra Yamani, Hye Jung Kang, Kouji Segawa

    We use inelastic neutron scattering to study the temperature dependence of the spin excitations of a detwinned superconducting YBa$_2$Cu$_3$O$_{6.45}$ ($T_c=48$ K). In contrast to earlier work on YBa$_2$Cu$_3$O$_{6.5}$ ($T_c=58$ K), where the prominent features in the magnetic spectra consist of a sharp collective magnetic excitation termed ``resonance&#39;&

  71. K. Hamaguchi, S. Shirai, T. T. Yanagida

    In supersymmetric (SUSY) models with the gravitino being the lightest SUSY particle (LSP), the SUSY breaking scale (i.e., the gravitino mass) could be determined by measuring the lifetime of the next-to-lightest SUSY particle (NLSP). However, for an ultralight gravitino of mass of O(1) eV, which is favored cosmologically, the determination of the SUSY breaki

  72. Mukremin Kilic, Piotr M. Kowalski, Fergal Mullally, William T. Reach

    We present the first mid-infrared spectra of two cool white dwarfs obtained with the Spitzer Space Telescope. We also present 3.5-8 micron photometry for 19 cool white dwarfs with 5000K < Teff < 9000K. We perform a detailed model atmosphere analysis of these white dwarfs by fitting their UBVRIJHK and Spitzer photometry with state-of-the-art model atmospheres

  73. Joshua D. Simon, Erik Rosolowsky

    We present initial results from the M33 Metallicity Project. Out of the thousands of cataloged HII regions in M33, only ~30 have electron-temperature based abundances in the literature. We have obtained Keck spectroscopy of a sample of ~200 HII regions in M33, with 61 detections of the [O III] 4363 A line that can be used for determining electron temperature

  74. Elizabeth Stanway, Malcolm Bremer, Matthew Lehnert

    A large population of z>5 Lyman break galaxies has been identified in recent years. However, the high redshift galaxies selected by different surveys are subject to a variety of selection effects - some overt, others more subtle. We present an analysis of sample completeness and contamination issues in high redshift surveys, focusing on surveys at z=5 and us

  75. S. D. Ellis, J. Huston, K. Hatakeyama, P. Loch

    In this article, we review some of the complexities of jet algorithms and of the resultant comparisons of data to theory. We review the extensive experience with jet measurements at the Tevatron, the extrapolation of this acquired wisdom to the LHC and the differences between the Tevatron and LHC environments. We also describe a framework (SpartyJet) for the

  76. M. Iori, A. Sergi

    Cosmic ray studies, in particular UHECR, can be in general supported by a directional, easy deployable, simple and robust detector. The design of this detector is based on the time of flight between two parallel tiles of scintillator, to distinguish particle passing through in opposite directions; by fine time resolution and pretty adjustable acceptance it i

  77. Jeremy Kahn, Mikhail Lyubich

    In this paper we prove {\it a priori bounds} for infinitely renormalizable quadratic polynomials satisfying a ``molecule condition&#39;&#39;. Roughly speaking, this condition ensures that the renormalization combinatorics stay away from the satellite types. These {\it a priori bounds} imply local connectivity of the corresponding Julia sets and the Mandelbro

  78. M. Schumann, M. Kreuz, M. Deissenroth, F. Glueck

    The proton asymmetry parameter C in neutron decay describes the correlation between neutron spin and proton momentum. In this Letter, the first measurement of this quantity is presented. The result C=-0.2377(26) agrees with the Standard Model expectation. The coefficient C provides an additional parameter for new and improved Standard Model tests. From a dif

  79. Claudio Chamon, Chang-Yu Hou, Roman Jackiw, Christopher Mudry

    Fermion-number fractionalization without breaking of time-reversal symmetry was recently demonstrated for a field theory in $(2+1)$-dimensional space and time that describes the couplings between massive Dirac fermions, a complex-valued Higgs field carrying an axial gauge charge of 2, and a U(1) axial gauge field. Charge fractionalization occurs whenever the

  80. David Branch, David J. Jeffery, Jerod Parrent, E. Baron

    A comparative study of optical spectra of Type Ia supernovae (SNe Ia) obtained near 1 week, 3 weeks, and 3 months after maximum light is presented. Most members of the four groups that were defined on the basis of maximum light spectra in Paper II (core normal, broad line, cool, and shallow silicon) develop highly homogeneous postmaximum spectra, although th

  81. Vijay Balasubramanian, Bartlomiej Czech, Yang-Hui He, Klaus Larjo

    We analyze the structure of heavy multitrace BPS operators in N = 1 superconformal quiver gauge theories that arise on the worldvolume of D3-branes on an affine toric cone. We exhibit a geometric procedure for counting heavy mesonic operators with given U(1) charges. We show that for any fixed linear combination of the U(1) charges, the entropy is maximized

  82. Ilwoo Cho, Palle E. T. Jorgensen

    In this paper, we characterize the C*-Algebra generated by partial isometries.

  83. Richard A. Hepworth

    This paper begins the study of Morse theory for orbifolds, or more precisely for differentiable Deligne-Mumford stacks. The main result is an analogue of the Morse inequalities that relates the orbifold Betti numbers of an almost-complex orbifold to the critical points of a Morse function on the orbifold. We also show that a generic function on an orbifold i

  84. L. Gyorfi, G. Morvai, S. Yakowitz

    This study concerns problems of time-series forecasting under the weakest of assumptions. Related results are surveyed and are points of departure for the developments here, some of which are new and others are new derivations of previous findings. The contributions in this study are all negative, showing that various plausible prediction problems are unsolv

  85. P. Dimopoulos, G. Herdoiza, F. Palombi, M. Papinutto

    Using Schroedinger Functional methods, we compute the non-perturbative renormalisation and renormalisation group running of several four-fermion operators, in the framework of lattice simulations with two dynamical Wilson quarks. Two classes of operators have been targeted: (i) those with left-left current structure and four propagating quark fields; (ii) al

  86. Aurelian Isar

    In the framework of the Lindblad theory for open quantum systems we determine the degree of quantum decoherence and classical correlations of a harmonic oscillator interacting with a thermal bath. The transition from quantum to classical behaviour of the considered system is analyzed and it is shown that the classicality takes place during a finite interval

  87. Marianela Carubelli, Orlando V. Billoni, Santiago Pighin, Sergio A. Cannas

    We show results from Monte Carlo simulations of a two dimensional Heisenberg model for ultrathin films with perpendicular anisotropy. A complete phase diagram is obtained as a function of anisotropy and temperature, spanning a wide range of behavior. We discuss our results in relation with experimental findings in different ultrathin films. We observe and ch

  88. F. Paletou, M. Lafon, P. Maeght, F. Grimaud

    BASS 2000 is the French solar database for ground-based instruments. We describe hereafter our organization, our tasks and the products we can deliver to the international community. Our prospects cover data mining into the THeMIS archive, a participation to the EST endeavour and the creation and curation of the ESPaDOnS/NARVAL stellar spectra database.

  89. Camil Muscalu, Terence Tao, Christoph Thiele

    In this article we prove that the $n$-linear operator whose symbol is the characteristic function of the simplex $Δ_n = ξ_1 < ... < ξ_n$ is bounded from $L^2 \times ... \times L^2$ into $L^{2/n}$, generalizing in this way our previous work on the &#34;bi-est&#34; operator (which corresponds to the case $n=3$) as well as Lacey-Thiele theorem on the bi-linear

  90. M. Gomez-Bock, M. Mondragón, M. Mühlleitner, M. Spira

    We present an introduction to the basic concepts of electroweak symmetry breaking and Higgs physics within the Standard Model and its supersymmetric extensions. A brief overview will also be given on alternative mechanisms of electroweak symmetry breaking. In addition to the theoretical basis, the present experimental status of Higgs physics and prospects at

  91. Simonetta Liuti, Saeed Ahmad, Gary R. Goldstein, Leonard Gamberg

    Exclusive $π^o$ electroproduction and related processes are suggested to investigate the chiral odd transversity distributions of quarks in the transversely polarized nucleon, $h_1(x)$, and its first moment, the tensor charge. The connection between a description based on partonic degrees of freedom, given in terms of generalized parton distributions, and Re

  92. Renato Pakter, Yan Levin, Felipe B. Rizzato

    The effect of conducting pipes on the equilibrium of intense nonaxisymmetric continuous beams of charged particles is investigated. For a cylindrical pipe and an elliptical beam, we obtain an exact closed form analytical expression for the electrostatic potential. Using a variational principle, we then explore the distortions that equilibrium beams suffer du

  93. Mariusz Krawiec

    We propose a new approximation scheme within equation of motion approach (EOM) to spin polarized transport through a quantum dot coupled to ferromagnetic leads. It has some advantages over a widely used in the literature standard EOM technique, in particular when we are interested in spin polarized quantities. Namely, it gives the values of the dot spin pola

  94. Nicolas Hadacek, Alexandre Nossov, Laurent Ranno, Pierre Strobel

    We report on the magnetic and transport studies of hafnium oxide thin films grown by pulsed-laser deposition on sapphire substrates under different oxygen pressures, ranging from 10-7 to 10-1 mbar. Some physical properties of these thin films appear to depend on the oxygen pressure during growth: the film grown at low oxygen pressure (P ~= 10-7 mbar) has a m

  95. V. F. Gopka, O. M. Ulyanov, S. M. Andrievsky

    We have proposed the new explanation of some magnetic chemically peculiar (MCP) stars anomalies, which is based on assumption that such stars can be the close binary systems with a secondary component being neutron star. Within this hypothesis one can naturally explain the main anomalous features of MCP stars: first of all, an existence of the short-lived ra

  96. Pierre-Vincent Koseleff, Daniel Pecker

    For every odd integer $N$ we give an explicit construction of a polynomial curve $\cC(t) = (x(t), y (t))$, where $°x = 3$, $°y = N + 1 + 2\pent N4$ that has exactly $N$ crossing points $\cC(t_i)= \cC(s_i)$ whose parameters satisfy $s_1 < ... < s_{N} < t_1 < ... < t_{N}$. Our proof makes use of the theory of Stieltjes series and Padé approximants. This allows

  97. Ludovic Dan Lemle, Liming Wu

    The main purpose is to generalize a theorem of Arendt about uniqueness of $C_0$-semigroups from Banach space setting to the general locally convex vector spaces, more precisely, we show that cores are the only domains of uniqueness for $C_0$-semigroups on locally convex spaces. As an application, we find a necessary and sufficient condition for that the mass

  98. E. Moroni, M. Caselle, F. Fogolari

    Specific binding of proteins to DNA is one of the most common ways in which gene expression is controlled. Although general rules for the DNA-protein recognition can be derived, the ambiguous and complex nature of this mechanism precludes a simple recognition code, therefore the prediction of DNA target sequences is not straightforward. DNA-protein interacti

  99. Trueman MacHenry, Kieh Wong

    Linear recursions of degree $k$ are determined by evaluating the sequence of Generalized Fibonacci Polynomials, $\{F_{k,n}(t_1,...,t_k)\}$ (isobaric reflects of the complete symmetric polynomials) at the integer vectors $(t_1,...,t_k)$. If $F_{k,n}(t_1,...,t_k) = f_n$, then $$f_n - \sum_{j=1}^k t_j f_{n-j} = 0,$$ and $\{f_n\}$ is a linear recursion of degree

  100. J. A. McLaughlin, A. W. Hood

    At this time there does not exist a robust set of rules connecting low and high $β$ waves across the $β\approx 1$ layer. The work here contributes specifically to what happens when a low $β$ fast wave crosses the $β\approx 1$ layer and transforms into high $β$ fast and slow waves. The nature of fast and slow magnetoacoustic waves is investigated in a finite