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August 2006 arXiv papers — page 9

Showing 801–900 of 4,247 papers

  1. Hajime Moriya

    We consider the univalence superselection rule. One would say perhaps ``There is no indication in nature to invalidate this rule. Fermions do not condensate!'' To explain our motivation, let us recall the correspondence of fermion systems and Pauli systems by the Jordan-Wigner transformation. For a finite lattice, fermion grading symmetry corresponds

  2. V. M. Shelkovich

    In this paper analysis of the concept of {\it associated homogeneous distributions} (generalized functions) is given, and some problems related to these distributions are solved. It is proved that (in the one-dimensional case) there exist {\it only} {\it associated homogeneous distributions} of order $k=1$. Next, we introduce a definition of {\it quasi assoc

  3. Olivier Garet, Régine Marchand

    Consider two epidemics whose expansions on $\mathbb{Z}^d$ are governed by two families of passage times that are distinct and stochastically comparable. We prove that when the weak infection survives, the space occupied by the strong one is almost impossible to detect: for instance, it could not be observed by a medium resolution satellite. We also recover t

  4. Shahar Mendelson, Alain Pajor, Nicole Tomczak-Jaegermann

    We present a simple solution to a question posed by Candes, Romberg and Tao on the uniform uncertainty principle for Bernoulli random matrices. More precisely, we show that a rectangular k*n random subgaussian matrix (with k < n) has the property that by arbitrarily extracting any m (with m < k) columns, the resulting submatrices are arbitrarily close to (mu

  5. Yannick Baraud, Lucien Birgé

    The purpose of this paper is to estimate the intensity of some random measure by a piecewise constant function on a finite partition of the underlying measurable space. Given a (possibly large) family of candidate partitions, we build a piecewise constant estimator (histogram) on each of them and then use the data to select one estimator in the family. Choos

  6. M. Cencelj, D. Repovš, A. Skopenkov

    For a given polyhedron $K\subset M$ the notation $R_M(K)$ denotes a regular neighborhood of $K$ in $M$. We study the following problem: find all pairs $(m,k)$ such that if $K$ is a compact $k$-polyhedron and $M$ a PL $m$-manifold, then $R_M(fK)\cong R_M(gK)$, for each two homotopic PL embeddings $f,g:K\to M$. We prove that $R_{S^{k+2}}(S^k)\not\cong S^k\time

  7. Adrien Dubouloz, Pierre-Marie Poloni

    L. Makar-Limanov computed the automorphisms groups of surfaces in $\mathbb{C}^{3}$ defined by the equations $x^{n}z-P(y)=0$, where $n\geq1$ and $P(y)$ is a nonzero polynomial. Similar results have been obtained by A. Crachiola for surfaces defined by the equations $x^{n}z-y^{2}-h(x)y=0$, where $n\geq2$ and $h(0)\neq0$, defined over an arbitrary base field. H

  8. Jyh-Haur Teh

    We embed the space of totally real $r$-cycles of a totally real projective variety into the space of complex $r$-cycles by complexification. We provide a proof of the holomorphic taffy argument in the proof of Lawson suspension theorem by using Chow forms and this proof gives us an analogous result for totally real cycle spaces. We use Sturm theorem to deriv

  9. Chengqing Li, Shujun Li, Der-Chyuan Lou, Dan Zhang

    Recently, a new domino signal encryption algorithm (DSEA) was proposed for digital signal transmission, especially for digital images and videos. This paper analyzes the security of DSEA, and points out the following weaknesses: 1) its security against the brute-force attack was overestimated; 2) it is not sufficiently secure against ciphertext-only attacks,

  10. Abram Falk, Mandar M. Deshmukh, Amy L. Prieto, Jeffrey J. Urban

    The stability of the superconducting dissipationless and resistive states in single-crystalline NbSe2 nanobelts is characterized by transport measurements in an external magnetic field (H). Current-driven electrical measurements show voltage steps, indicating the nucleation of phase-slip structures. Well below the critical temperature, the position of the vo

  11. Garry W. Angus, HongSheng Zhao

    A special purpose N-body simulation has been built to understand the tidal heating of the smallest dark matter substructures ($10^{-6}\msun$ and 0.01pc) from the grainy potential of the Milky Way due to individual stars in the disk and the bulge. To test the method we first run simulations of single encounters of microhalos with an isolated star, and compare

  12. Y. K. Jin, S. N. Zhang, J. F. Wu

    Hardness ratios are commonly used in X-ray photometry to indicate spectral properties roughly. It is usually defined as the ratio of counts in two different wavebands. This definition, however, is problematic when the counts are very limited. Here we instead define hardness ratio using the $λ$ parameter of Poisson processes, and develop an estimation method

  13. Shoji Kato, Jun Fukue

    We have proposed in previous papers that the high-frequency pair QPOs observed in black-hole binaries with frequency ratio 3:2 are inertial-acoustic oscillations (nearly horizontal oscillations with no node in the vertical direction) or g-mode oscillations, which are resonantly excited on warped relativistic disks. The resonance occurs through horizontal mot

  14. Serguei Vorobiov

    The Pierre Auger Observatory aims to determine the nature and origin of the ultra-high energy cosmic rays (UHECR). The Auger hybrid detector combines fluorescence observations of extended air showers, initiated in the atmosphere by these most energetic particles, with measures of the shower front at the ground level by its large array of Cherenkov water tank

  15. Laird M. Close, Ben Zuckerman, Inseok Song, Travis Barman

    We imaged five objects near the star forming clouds of Ophiuchus with the Keck Laser Guide Star AO system. We resolved Allers et al. (2006)&#39;s #11 (Oph 16222-2405) and #16 (Oph 16233-2402) into binary systems. The #11 object is resolved into a 243 AU binary, the widest known for a very low mass (VLM) binary. The binary nature of #11 was discovered first b

  16. Thomas Marley, Mark W. Rogers, Hideto Sakurai

    Given a Noetherian local ring (R,m) it is shown that there exists an integer l such that R is Gorenstein if and only if some system of parameters contained in m^l generates an irreducible ideal. We obtain as a corollary that R is Gorenstein if and only if every power of the maximal ideal contains an irreducible parameter ideal.

  17. Giorgio Torrieri, Johann Rafelski

    We show that a measurement of the reaction energy dependence of relative hadron resonance yields in heavy ion collisions can be used to study the phase structure of the dense QCD matter created in these collisions, and investigate the origin of the trends observed in the excitation functions of certain soft hadronic observables. We show that presence of chem

  18. A. P. Bakulev, A. V. Pimikov

    We show that the minimal Gaussian model of nonlocal vacuum quark and quark-gluon condensates in QCD generates the non-transversity of vector current correlators. We suggest the improved Gaussian model of the nonperturbative QCD vacuum, which respects QCD equations of motion and minimizes the revealed gauge-invariance breakdown. We obtain the refined values o

  19. Vladimir Nikiforov

    Let f(n,m) be the maximum of the sum of the squares of degrees of a graph with n vertices and m edges. Summarizing earlier research, we present a concise, asymptotically sharp upper bound on f(n,m), better than the bound of de Caen for almost all n and m.

  20. Evgeny Sorkin

    The nonuniform black strings branch, which emerges from the critical Gregory-Laflamme string, is numerically constructed in dimensions 6 <= D <= 11 and extended into the strongly non-linear regime. All the solutions are more massive and less entropic than the marginal string. We find the asymptotic values of the mass, the entropy and other physical variables

  21. Friedrich Hegenbarth, Dušan Repovš

    Following Bryant, Ferry, Mio and Weinberger we construct generalized manifolds as limits of controlled sequences p_i: X_i --> X_{i-1} : i = 1,2,... of controlled Poincaré spaces. The basic ingredient is the epsilon-delta-surgery sequence recently proved by Pedersen, Quinn and Ranicki. Since one has to apply it not only in cases when the target is a manifold,

  22. E. V. Ferapontov, S. R. Svirshchevskii

    In this short note we discuss ordinary differential equations which linearize upon one (or more) differentiations. Although the subject is fairly elementary, equations of this type arise naturally in the context of integrable systems.

  23. Reinhold Oppermann, Manuel J. Schmidt, David Sherrington

    Numerical results up to 42nd order of replica symmetry breaking (RSB) are used to predict the singular structure of the SK spin glass at T=0. We confirm predominant single parameter scaling and derive corrections for the T=0 order function q(a), related to a Langevin equation with pseudotime 1/a. a=0 and a=\infty are shown to be two critical points for \inft

  24. M. Casals, S. R. Dolan, P. Kanti, E. Winstanley

    In this work, we have continued the study of the Hawking radiation on the brane from a higher-dimensional rotating black hole by investigating the emission of fermionic modes. A comprehensive analysis is performed that leads to the particle, power and angular momentum emission rates, and sheds light on their dependence on fundamental parameters of the theory

  25. J. G. Korner, Z. Merebashvili, M. Rogal

    We calculate the one-loop squared contributions to the next-to-next-to-leading order ${\cal O}(α^2α_s^2)$ radiative QCD corrections for the production of heavy quark pairs in the collisions of unpolarized on--shell photons. In particular, we present analytical results for the squared matrix elements that correspond to the product of the one--loop amplitudes.

  26. S. M. Nagiyev, E. I. Jafarov, R. M. Imanov

    An exact approach for the factorization of the relativistic linear singular oscillator is proposed. This model is expressed by the finite-difference Schrödinger-like equation. We have found finite-difference raising and lowering operators, which are with the Hamiltonian operator form the close Lie algebra of the $SU(1, 1)$ group.

  27. Luca Baiotti, Luciano Rezzolla

    A paradigm deeply rooted in modern numerical relativity calculations prescribes the removal of those regions of the computational domain where a physical singularity may develop. We here challenge this paradigm by performing three-dimensional simulations of the collapse of uniformly rotating stars to black holes without excision. We show that this choice, co

  28. Lan Zhou, Y. B. Gao, Z. Song, C. P. Sun

    We study the coherent control of microwave photons propagating in a superconducting waveguide consisting of coupled transmission line resonators, each of which is connected to a tunable charge qubit. While these coupled line resonators form an artificial photonic crystal with an engineered photonic band structure, the charge qubits collectively behave as spi

  29. Brian F. Gerke, Jeffrey A. Newman, S. M. Faber, Michael C. Cooper

    We explore the behavior of the blue galaxy fraction over the redshift range 0.75 <= z <= 1.3 in the DEEP2 Survey, both for field galaxies and for galaxies in groups. The primary aim is to determine the role that groups play in driving the evolution of galaxy colour at high z. The colour segregation observed between local group and field samples is already in

  30. Nicolás Andruskiewitsch, Gastón Andrés García

    We give a necessary and sufficient condition for two Hopf algebras presented as central extensions to be isomorphic, in a suitable setting. We then study the question of isomorphism between the Hopf algebras constructed in 0707.0070v1 as quantum subgroups of quantum groups at roots of 1. Finally, we apply the first general result to show the existence of inf

  31. Liu Lianshou, Shi Shusu, Du Jiaxin

    The inversion-asymmetry of the emission source in relativistic heavy ion collision under the Bertsch-Pratt convention is discussed and explicitly exhibited by a Monte Carlo model. The Gaussian source function popularly used in the HBT analysis of relativistic heavy ion collisions is invalid in this case. An inversion-asymmetric source function is suggested.

  32. M. A. de Ponte, S. S. Mizrahi, M. H. Y. Moussa

    We consider a network of interacting resonators and analyze the physical ingredients that enable the emergence of relaxation-free and decoherence-free subspaces. We investigate two different situations: i) when the whole network interacts with a common reservoir and ii) when each resonator, strongly coupled to each other, interacts with its own reservoir. Ou

  33. H. T. Cui, K. Li, X. X. Yi

    The relation between the geometric phase and quantum phase transition has been discussed in the Lipkin-Meshkov-Glick model. Our calculation shows the ability of geometric phase of the ground state to mark quantum phase transition in this model. The possibility of the geometric phase or its derivatives as the universal order parameter of characterizing quantu

  34. Paul O&#39;Hara

    In the history of quantum mechanics, much has been written about the double-slit experiment, and much debate as to its interpretation has ensued. Indeed, to explain the interference patterns for sub-atomic particles, explanations have been given not only in terms of the principle of complementarity and wave-particle duality but also in terms of quantum consc

  35. Pierre Sens, Nir gov

    During the aging of the red-blood cell, or under conditions of extreme echinocytosis, membrane is shed from the cell plasma membrane in the form of nano-vesicles. We propose that this process is the result of the self-adaptation of the membrane surface area to the elastic stress imposed by the spectrin cytoskeleton, via the local buckling of membrane under i

  36. Rubens de Melo Marinho

    A didatic approach of the Noether&#39;s theorem in classical mechanics is derived and used to obtain the laws of conservation.

  37. I. Furno, T. P. Intrator, S. Abbate, T. Madziwa-Nussinov

    First experimental measurements are presented for the kink instability in a linear plasma column which is insulated from an axial boundary by finite sheath resistivity. Instability threshold below the classical Kruskal-Shafranov threshold, axially asymmetric mode structure and rotation are observed. These are accurately reproduced by a recent kink theory, wh

  38. Darren Tapp

    Let $f$ and $g$ be reduced homogeneous polynomials in separate sets of variables. We establish a simple formula that relates the eigenspace decomposition of the monodromy operator on the Milnor fiber cohomology of $fg$ to that of $f$ and $g$ separately. We use a relation between local systems and Milnor fiber cohomology that has been established by D. Cohen

  39. Takashi Taniguchi

    Let $k$ be a number field and $O$ the ring of integers. In the previous paper [T06] we study the Dirichlet series counting discriminants of cubic algebras of $O$ and derive some density theorems on distributions of the discriminants by using the theory of zeta functions of prehomogeneous vector spaces. In this paper we consider these objects under imposing f

  40. Takashi Taniguchi

    In this paper, we consider the structure of rational orbit of some prehomogeneous vector spaces originally motivated by Wright and Yukie. After we give a refinement of Wright-Yukie&#39;s construction, we apply it to the inner forms of the $D_5$ and $E_7$ types. Parameterizations of reducible algebras for the cubic cases are included.

  41. Aaron Bertram, Renzo Cavalieri, Gueorgui Todorov

    Hurwitz numbers count ramified covers of a Riemann surface with prescribed monodromy. As such, they are purely combinatorial objects. Tautological classes, on the other hand, are distinguished classes in the intersection ring of the moduli spaces of Riemann surfaces of a given genus, and are thus ``geometric.&#39;&#39; Localization computations in Gromov-Wit

  42. F. Vaccarino

    We show that the $n-$th symmetric product of an affine scheme $X=\mathrm{Spec} A$ over a characteristic zero field is isomorphic as a scheme to the quotient by the general linear group of the scheme parameterizing $n-$dimensional linear representations of $A$. As a consequence we give generators and relations of the related rings of invariants as well as the

  43. Friedrich Hegenbarth, Dušan Repovš

    The validity of Freedman&#39;s disk theorem is known to depend only on the fundamental group. It was conjectured that it fails for nonabelian free fundamental groups. If this were true then surgery theory would work in dimension four. Recently, Krushkal and Lee proved a surprising result that surgery theory works for a large special class of 4-manifolds with

  44. W Rossman, N Schmitt

    We give necessary and sufficient local conditions for the simultaneous unitarizability of a set of analytic matrix maps from an analytic 1-manifold into SL_n(C) under conjugation by a single analytic matrix map. We apply this result to the monodromy arising from an integrable partial differential equation to construct a family of k-noids, genus-zero constant

  45. Steven G. Krantz

    We develop a new technique for studying the boundary limiting behavior of a holomorphic function on a domain $Ω$ -- both in one and several complex variables. The approach involves two new localized maximal functions. As a result of this methodology, theorems of Calderón type about local boundary behavior on a set of positive measure may be proved in a new a

  46. Taekyun Kim

    The purpose of this paper is to construct q-Euler numbers and polynomials by using p-adic q-integral equations on Zp. Finally, we will give some interesting formulae related to these q-Euler numbers and polynomials.

  47. Steven G. Krantz

    We provide a simple method for obtain boundary asymptotics of the Poisson kernel on a domain in $\RR^N$.

  48. J. Schefer, D. Schaniel, V. Pomjakushin, U. Stuhr

    We report high-resolution neutron powder diffraction on Sr0.61Ba0.39Nb2O6, SBN61, in the temperature range 15-500 K. The results indicate that the low-temperature anomalies (T<100K) observed in the dielectric dispersion are due to small changes in the incommensurate modulation of the NbO6-octahedra, as no structural phase transition of the average structure

  49. W. A. Little, M. J. Holcomb, G. Ghiringhelli, L. Braicovich

    We have measured the near-normal reflectance of Tl2Ba2CaCu2O8 (Tl2212) for energies from 0.1 to 4.0 eV at room temperature and used a Kramers-Kronig analysis to find the complex, frequency dependent dielectric function, from which the optical conductivity was determined. Using Thermal-Difference-Reflectance (TDR) Spectroscopy the reflectance of the sample in

  50. Kazuo Hida

    Ground state properties of the S=1/2 frustrated Heisenberg chain with period 3 exchange modulation are investigated using the numerical diagonalization and DMRG method. It is known that this model has a magnetization plateau at 1/3 of the saturation magnetization M_s. On the other hand, the ground state is ferrimagnetic even in the absence of frustration if

  51. Yoshiyuki Miyamoto, Angel Rubio, David Tomanek

    Combining time-dependent density functional calculations for electrons with molecular dynamics simulations for ions, we investigate the dynamics of excited carriers in a (3,3) carbon nanotube at different temperatures. Following an hv=6.8 eV photoexcitation, the carrier decay is initially dominated by efficient electron-electron scattering. At room temperatu

  52. G. W. Fernando, A. N. Kocharian, K. Palandage, Tun Wang

    Exact thermal studies of small (4-site, 5-site and 8-site) Hubbard clusters with local electron repulsion yield intriguing insight into phase separation, charge-spin separation, pseudogaps, condensation, in particular, pairing fluctuations away from half filling (near optimal doping). These exact calculations, carried out in canonical (i.e. for fixed electro

  53. Niraj Kumar, Goutam Tripathy

    We study front propagation in the reaction diffusion process $\{A\stackrelε\to2A, A\stackrel {ε_t}\to3A\}$ on a one dimensional (1d) lattice with hard core interaction between the particles. Using the leading particle picture, velocity of the front in the system is computed using different approximate methods, which is in good agreement with the simulation r

  54. T. Klimczuk, Q. Xu, E. Morosan, H. W. Zandbergen

    Mg10Ir19B16, a previously unreported compound in the Mg-Ir-B chemical system, is found to be superconducting at temperatures near 5 K. The fact that the compound exhibits a range of superconducting temperatures between 4 and 5 K suggests that a range of stoichiometries is allowed, though no structural evidence for this is observed. The compound has a large,

  55. D. L. Tucker, S. Kent, M. W. Richmond, J. Annis

    The photometric calibration of the Sloan Digital Sky Survey (SDSS) is a multi-step process which involves data from three different telescopes: the 1.0-m telescope at the US Naval Observatory (USNO), Flagstaff Station, Arizona (which was used to establish the SDSS standard star network); the SDSS 0.5-m Photometric Telescope (PT) at the Apache Point Observato

  56. J. E. Gizis, J. Harvin

    We present the first far-red spectra of the L subdwarf 2MASS J16262034+3925190 and the late M/early L subdwarf 2MASS J16403197+1231068. We confirm the ultracool subdwarf nature of these objects. 2M1626+3925 shows strong K I absorption, like an L4 dwarf, and is very similar to, but hotter than, the late L subdwarf 2MASS J05325346+8246465. It is unambiguously

  57. Vadim V. Bobylev, Maxim Yu. Khovritchev

    Based on the Ogorodnikov-Milne model, we analyze the proper motions of Tycho-2 and UCAC2 stars. We have established that the model component that describes the rotation of all stars under consideration around the Galactic y axis differs significantly from zero at various magnitudes. We interpret this rotation found using the most distant stars as a residual

  58. Brendon J. Brewer, Timothy R. Bedding, Hans Kjeldsen, Dennis Stello

    Stellar oscillations can provide a wealth of information about a star, which can be extracted from observed time series of the star&#39;s brightness or radial velocity. In this paper we address the question of how to extract as much information as possible from such a dataset. We have developed a Markov Chain Monte Carlo (MCMC) code that is able to infer the

  59. Zhe Chen, Jiang Zhang, YanPing Chen, WenYuan Cui

    The supernova yields of r-process elements are obtained as a function of the mass of their progenitor stars from the abundance patterns of extremely metal-poor stars on the left-side [Ba/Mg]-[Mg/H] boundary with a procedure proposed by Tsujimoto and Shigeyama. The ejected masses of r-process elements associated with stars of progenitor mass $M_{ms}\leq18M_{\

  60. Richard H. Cyburt, John Ellis, Brian D. Fields, Keith A. Olive

    If the gravitino is the lightest supersymmetric particle and the long-lived next-to-lightest sparticle (NSP) is the stau, the charged partner of the tau lepton, it may be metastable and form bound states with several nuclei. These bound states may affect the cosmological abundances of Li6 and Li7 by enhancing nuclear rates that would otherwise be strongly su

  61. John G. Hartnett

    Equations of motion, in cylindrical co-ordinates, for the observed rotation of gases within the gravitational potential of spiral galaxies have been derived from Carmeli&#39;s Cosmological General Relativity theory. A Tully-Fisher type relation results and rotation curves are reproduced without the need for non-baryonic halo dark matter. Two acceleration reg

  62. W. Chou

    This paper has been withdrawn by the author due to a crucial error in the force equation.

  63. Bjoern S. Schmekel, Richard V. E. Lovelace

    We investigate the effect of shear in the flow of charged particle equilibria that are unstable to the Coherent Synchrotron Radiation (CSR) instability. Shear may act to quench this instability because it acts to limit the size of the region with a fixed phase relation between emitters. The results are important for the understanding of astrophysical sources

  64. Thomas DeGrand, Zhaofeng Liu, Stefan Schaefer

    We compute the condensate in QCD with two flavors of dynamical fermions using numerical simulation. The simulations use overlap fermions, and the condensate is extracted by fitting the distribution of low lying eigenvalues of the Dirac operator in sectors of fixed topological charge to the predictions of Random Matrix Theory.

  65. Hisham Sati

    The reduction of the E8 gauge theory to ten dimensions leads to a loop group, which in relation to twisted K-theory has a Dixmier-Douady class identified with the Neveu-Schwarz H-field. We give an interpretation of the degree two part of the eta-form by comparing the adiabatic limit of the eta invariant with the one loop term in type IIA. More generally, sta

  66. Pavel Gumenuk

    Let f_n be a sequence of analytic functions in a domain U with a common attracting fixed point z_0. Suppose that f_n converges to f_0 uniformly on each compact subset of U and that z_0 is a Siegel point of f_0. We establish a sufficient condition for the immediate basins of attraction $\mathcal A^*(z_0,f_n,U)$ to form a sequence that converges to the Siegel

  67. A. Duggleby, K. S. Ball, M. R. Paul

    The dynamical behavior of propagating structures, determined from a Karhunen-Lo`eve decomposition, in turbulent pipe flow undergoing reverse transition to laminar flow is investigated. The turbulent flow data is generated by a direct numerical simulation started at a fully turbulent Reynolds number of Re_τ=150, which is slowly decreased until Re_τ=95. At thi

  68. A. Duggleby, K. S. Ball, M. R. Paul

    The results of a comparative analysis based upon a Karhunen-Loève expansion of turbulent pipe flow and drag reduced turbulent pipe flow by spanwise wall oscillation are presented. The turbulent flow is generated by a direct numerical simulation at a Reynolds number $Re_τ= 150$. The spanwise wall oscillation is imposed as a velocity boundary condition with an

  69. Serban T. Belinschi, Alexandru Nica

    On the space of (non-commutative) distributions of k-tuples of selfadjoint elements in a $C^*$-probability space $D_c(k)$, one has an operation $\freeplus$ of free additive convolution, and one can consider the subspace $D_c^{inf-div}$ of distributions which are infinitely divisible with respect to this operation. The linearizing transform for free additive

  70. A. Duggleby, K. S. Ball, M. R. Paul, P. F. Fischer

    The results of an analysis of turbulent pipe flow based on a Karhunen-Lo`eve decomposition are presented. The turbulent flow is generated by a direct numerical simulation of the Navier-Stokes equations using a spectral element algorithm at a Reynolds number Re_τ=150. This simulation yields a set of basis functions that captures 90% of the energy after 2,453

  71. V. O. Garlea, A. Zheludev, T. Masuda, L. -P. regnault

    The weakly coupled quasi-one-dimensional spin ladder compound (CH$_3$)$_2$CHNH$_3$CuCl$_3$ is studied by neutron scattering in magnetic fields exceeding the critical field of Bose-Einstein condensation of magnons. Commensurate long-range order and the associated Goldstone mode are detected and found to be similar to those in a reference 3D quantum magnet. Ho

  72. G. Ghisellini, G. Ghirlanda, F. Tavecchio

    We study the optical-UV/X-ray spectral energy distribution of GRB 060218 during the prompt phase and during what seems to be the afterglow phase. The results are puzzling, since if the opt-UV and the X-ray emission belong to a single backbody (BB), then its luminosity is too large, and this BB cannot be interpreted as the signature of the shock breakout of t

  73. U. Brandes, D. Delling, M. Gaertler, R. Goerke

    Several algorithms have been proposed to compute partitions of networks into communities that score high on a graph clustering index called modularity. While publications on these algorithms typically contain experimental evaluations to emphasize the plausibility of results, none of these algorithms has been shown to actually compute optimal partitions. We h

  74. Joseph D. Masters

    We show that if $M$ is a fibered, orientable 3-manifold, and if $π_1 M$ has 1-relator presentation, then the presentation is induced by a Heegaard splitting of $M$. A corollary is that, for these manifolds, the rank of $π_1 M$ is equal to the &#34;restricted&#34; Heegaard genus of $M$. We also explore the analogy between 1-relator groups and Haken 3-manifold

  75. Luis Caffarelli, Luis Silvestre

    The operator square root of the Laplacian $(-\lap)^{1/2}$ can be obtained from the harmonic extension problem to the upper half space as the operator that maps the Dirichlet boundary condition to the Neumann condition. In this paper we obtain similar characterizations for general fractional powers of the Laplacian and other integro-differential operators. Fr

  76. Matthias Christandl, Artur Ekert, Michal Horodecki, Pawel Horodecki

    Assume that two distant parties, Alice and Bob, as well as an adversary, Eve, have access to (quantum) systems prepared jointly according to a tripartite state. In addition, Alice and Bob can use local operations and authenticated public classical communication. Their goal is to establish a key which is unknown to Eve. We initiate the study of this scenario

  77. Cristina Balderrama, Wilfredo Urbina

    In this paper we consider an alternative orthogonal decomposition of the space $L^2$ associated to the $d$-dimensional Jacobi measure and obtain an analogous result to P.A. Meyer&#39;s Multipliers Theorem for d-dimensional Jacobi expansions. Then we define and study the Fractional Integral, the Fractional Derivative and the Bessel potentials induced by the J

  78. Harry J. Lipkin

    A new experimental analysis of $B\to Kπ$ decays provides finite experimental values for the contributions from interference terms between the dominant penguin amplitude and the color-favored and color-suppressed tree amplitudes. These results can explain the puzzling failure to see CP violation in $B^\pm\to Kπ$ decays. Tree-penguin interference contributions

  79. Michael C. Mackey, Marta Tyran-Kaminska

    We establish a new functional central limit theorem result for non-invertible measure preserving maps that are not necessarily ergodic, using the Perron-Frobenius operator. We apply the result to asymptotically periodic transformations and give an extensive specific example of asymptotically periodic transformations by using the tent map.

  80. Noam Soker

    I derive the condition for narrow jets with varying axis, e.g., precessing jets, to inflate more or less spherical (fat) bubbles in planetary nebulae and clusters of galaxies. This work follows a previous work dealing with wide jets, i.e., having a wide opening angle. The expressions derive here are qualitatively and quantitatively similar to the conditions

  81. J. Fransson

    Weakly coupled quantum dots in the Pauli spin blockade regime are considered with respect to spin-dependent transport. By attaching one half-metallic and one non-magnetic lead, the Pauli spin blockade if formed by a pure triplet state with spin moment $S_z=1$ or -1. Furthermore, additional spin blockade regimes emerge because of full occupation in states wit

  82. Bhaskar Dutta, Jason Kumar

    We introduce a novel mechanism for baryogenesis, in which mixed anomalies between the hidden sector and $U(1)_{baryon}$ drive the baryon asymmetry. We demonstrate that this mechanism occurs quite naturally in intersecting-brane constructions of the Standard Model, and show that it solves some of the theoretical difficulties faced in matching baryogenesis to

  83. A. Barroso, P. M. Ferreira, R. Santos, Joao P. Silva

    We show that the vacuum structure of a generic multi-Higgs-doublet model shares several important features with the vacuum structure of the two and three Higgs-doublet model. In particular, one can still define the usual charge breaking, spontaneous CP breaking and normal (charge and CP preserving) stationary points. We analyse the possibility of charge or s

  84. Sezgin Aygun, Ismail Tarhan, Husnu Baysal, Melis Aygun

    This paper has been removed by arXiv administrators because it plagiarizes gr-qc/0603075, 0706.3245, gr-qc/0403097, gr-qc/0404108, gr-qc/0303034, hep-th/0206052, and others. This paper has excessive overlap with the following papers also written by the authors or their collaborators: 0704.0525 and others.

  85. Kazuyuki Furuuchi

    This is an introductory lecture note aiming at providing an overview of the AdS-CFT correspondence at weak &#39;t Hooft coupling at finite temperature. The first aim of this note is to describe the equivalence of three interesting thermodynamical phenomena in theoretical physics, namely, Hawking-Page transition to black hole geometry, deconfinement transitio

  86. Yoichi Chizaki, Shigeaki Yahikozawa

    We canonically quantize closed string theory in the pp-wave background with a non-zero flux of the three-form field strength by using the covariant BRST operator formalism. In this canonical quantization, we completely construct new covariant free-mode representations, for which it is particularly important to take account of the commutation relations of the

  87. Stephen D. H. Hsu

    Topology change -- the creation of a disconnected baby universe -- due to black hole collapse may resolve the information loss paradox. Evolution from an early time Cauchy surface to a final surface which includes a slice of the disconnected region can be unitary and consistent with conventional quantum mechanics. We discuss the issue of cluster decompositio

  88. Martin Forde

    This paper has been withdrawn

  89. Jai Grover, Jan B Gutowski, Wafic Sabra

    We examine supersymmetric solutions of N=2, D=5 gauged supergravity coupled to an arbitrary number of abelian vector multiplets using the spinorial geometry method. By making use of methods developed in hep-th/0606049 to analyse preons in type IIB supergravity, we show that there are no solutions preserving exactly 3/4 of the supersymmetry.

  90. Feng Yuan, Andrzej A. Zdziarski, Yongquan Xue, Xue-Bing Wu

    We study hard states of the black-hole binary XTE J1550--564 during its 2000 outburst. In order to explain those states at their highest luminosities, $L\sim 10%$ of the Eddington luminosity, $L_{\rm E}$, we propose a specific hot accretion flow model. We point out that the highest values of the hard-state $L$ are substantially above the $L$ an advection-dom

  91. KTeV collaboration, E. Abouzaid

    Using the published KTeV sample of 2 million KL-> pi e nu decays and a new form factor expansion with a rigorous bound on higher order terms, we present a new determination of the KL->pi e nu form factor and phase space integral. Compared to the previous KTeV result, the uncertainty in the new form factor expansion is negligible and results in an overall unc

  92. Osvaldo Pessoa, Olival Freire, Alexis De Greiff

    In 1966, the Brazilian physicist Klaus Tausk circulated a preprint from the International Centre for Theoretical Physics, in Trieste, criticizing the theory put forward by Daneri, Loinger & Prosperi on the measurement problem in quantum mechanics. This led to a heated controversy, which reflected two opposing camps within the orthodox interpretation of quant

  93. Bo Zhang, Jalal Fadili, Jean Luc Starck, Seth W. Digel

    Methods based on hypothesis tests (HTs) in the Haar domain are widely used to denoise Poisson count data. Facing large datasets or real-time applications, Haar-based denoisers have to use the decimated transform to meet limited-memory or computation-time constraints. Unfortunately, for regular underlying intensities, decimation yields discontinuous estimates

  94. A. Mildenberger, F. Evers

    The wavefunction statistics at the Anderson transition in a 2d disordered electron gas with spin-orbit coupling is studied numerically. In addition to highly accurate exponents ($α_0{=}2.172\pm 0.002, τ_2{=}1.642\pm 0.004$), we report three qualitative results: (i) the anomalous dimensions are invariant under $q\to (1-q)$ which is in agreement with a recent

  95. A. Widom, L. Larsen

    The process of radiation induced electron capture by protons or deuterons producing new ultra low momentum neutrons and neutrinos may be theoretically described within the standard field theoretical model of electroweak interactions. For protons or deuterons in the neighborhoods of surfaces of condensed matter metallic hydride cathodes, such conversions are

  96. G. Molchan

    Let x(s), s in R^d be a Gaussian self-similar random process of index H. We consider the problem of log-asymptotics for the probability p(T) that x(s), x(0)=0 does not exceed a fixed level in a star-shaped expanding domain TxG as T>>1. We solve the problem of the existence of the limit, theta:=lim (-log p(T))/(log T)^D, T>>1, for the fractional Brownian shee

  97. Matthias R Gaberdiel, Ingo Runkel

    The boundary theory for the c=-2 triplet model is investigated in detail. In particular, we show that there are four different boundary conditions that preserve the triplet algebra, and check the consistency of the corresponding boundary operators by constructing their OPE coefficients explicitly. We also compute the correlation functions of two bulk fields

  98. Satoshi Murai, Pooja Singla

    Let $K$ be a field, $S$ a polynomial ring and $E$ an exterior algebra over $K$, both in a finite set of variables. We study rigidity properties of the graded Betti numbers of graded ideals in $S$ and $E$ when passing to their generic initial ideals. First, we prove that if the graded Betti numbers $β_{ii+k}^S(S/I)=β_{ii+k}^S(S/\Gin(I))$ for some $i>1$ and $k

  99. Arseni Goussev, Klaus Richter

    We investigate the sensitivity of the time evolution of semiclassical wave packets in two-dimensional chaotic billiards with respect to local perturbations of their boundaries. For this purpose, we address, analytically and numerically, the time decay of the Loschmidt echo (LE). We find the LE to decay exponentially in time, with the rate equal to the classi

  100. Alexei Borodin, Patrik L. Ferrari, Michael Prähofer, Tomohiro Sasamoto

    We consider the joint distributions of particle positions for the continuous time totally asymmetric simple exclusion process (TASEP). They are expressed as Fredholm determinants with a kernel defining a signed determinantal point process. We then consider certain periodic initial conditions and determine the kernel in the scaling limit. This result has been