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April 2008 arXiv papers — page 18

Showing 1,7011,800 of 4,892 papers

  1. Emeric Falize, Claire Michaut, Serge Bouquet, Cécile Cavet

    In this paper we study specific classes of radiating shocks which are widely spread in astrophysical environments. We present more general solutions of their structure and proceed to the analytical determination of physical quantities.

  2. Chantal Enguehard, Jean-Didier Graton

    Observing electronic voting from an international point of view gives some perspective about its genesis and evolution. An analysis of the voting process through its cultural, ontological, legal and political dimensions explains the difficulty to normalize this process. It appears that international organizations are not capable to properly defend the fundam

  3. Hidehiko Shimada

    A new class of deformation of the matrix model of M-theory is considered. The deformation is analogous to the so-called $\b$-deformation of $D=3+1$, $\mN=4$ Super Yang-Mills theory, which preserves the conformal symmetry. It is shown that the deformed matrix model can be considered as a matrix model of M-theory on a certain curved background in eleven-dimens

  4. Dario Nunez, Jesus Zavala, Lukas Nellen, Roberto A. Sussman

    We derive an expression for the entropy of a dark matter halo described by a Navarro-Frenk-White model with a core. The comparison of this entropy with the one of dark matter at the freeze-out era allows us to constraint the parameter space in mSUGRA models. Moreover, joining these constraints with the ones obtained from the usual abundance criteria and dema

  5. Wenjun Liu, Quoc Anh Ngo

    In this paper we derive a new inequality of Ostrowski-Gruss type on time scales and thus unify corresponding continuous and discrete versions. We also apply our result to the quantum calculus case.

  6. Wenjun Liu, Quoc Anh Ngo

    In this paper we first generalize the Ostrowski inequality on time scales for k points and then unify corresponding continuous and discrete versions. We also point out some particular Ostrowski type inequalities on time scales as special cases.

  7. Adam Boocher, Bradley Froehle

    We provide a method for factoring all bounded ratios of the form $$\det A(I_1|I_1')\det A(I_2|I_2')/\det A(J_1|J_1')\det A(J_2|J_2')$$ where $A$ is a totally positive matrix, into a product of more elementary ratios each of which is bounded by 1, thus giving a new proof of Skandera's result. The approach we use generalizes the one employe

  8. Natasha Jonoska, Anne Taormina, Reidun Twarock

    Blueprints of polyhedral cages with icosahedral symmetry made of circular DNA molecules are provided. The basic rule is that every edge of the cage is met twice in opposite directions by the DNA strand, and vertex junctions are realised by a set of admissible junction types. As nanocontainers for cargo storage and delivery, the icosidodecahedral cages are of

  9. Karl D. Gordon, Charles W. Engelbracht, George H. Rieke, K. A. Misselt

    The aromatic features in M101 were studied spectroscopically and photometrically using observations from all three instruments on the Spitzer Space Telescope. The global SED of M101 shows strong aromatic feature (commonly called PAH feature) emission. The spatially resolved spectral and photometric measurements of the aromatic feature emission show strong va

  10. Norbert Grewe, Sebastian Schmitt, Torben Jabben, Frithjof B. Anders

    For the treatment of interacting electrons in crystal lattices approximations based on the picture of effective sites, coupled in a self-consistent fashion, have proven very useful. Particularly in the presence of strong local correlations, a local approach to the problem, combining a powerful method for the short ranged interactions with the lattice propaga

  11. Petrus H. Potgieter

    This paper is an overview of results that show the Brouwer fixed-point theorem (BFPT) to be essentially non-constructive and non-computable. The main results, the counter-examples of Orevkov and Baigger, imply that there is no procedure for finding the fixed point in general by giving an example of a computable function which does not fix any computable poin

  12. M. Rotondo, R. Ruffini, S. -S. Xue

    Based on the Thomas-Fermi approach, we describe and distinguish the electron distributions around extended nuclear cores: (i) in the case that cores are neutral for electrons bound by protons inside cores and proton and electron numbers are the same; (ii) in the case that super charged cores are bare, electrons (positrons) produced by vacuum polarization are

  13. Michitaka Miyauchi

    Let F_0 be a non-archimedean local field of odd residual characteristic and let G be the unramified unitary group U(2,2) defined over F_0. In this paper, we give a classification of the irreducible smooth representations of G of non-integral level using the Hecke algebraic method developed by Allen Moy for GSp(4).

  14. Yves Atchade, Nicolas Lartillot, Christian P. Robert

    This paper deals with some computational aspects in the Bayesian analysis of statistical models with intractable normalizing constants. In the presence of intractable normalizing constants in the likelihood function, traditional MCMC methods cannot be applied. We propose an approach to sample from such posterior distributions. The method can be thought as a

  15. J. C. Barba, V. I. Inozemtsev

    We describe a class of the singular solutions to the multicomponent analogs of the Lam{é} equation, arising as equations of motion of the elliptic Calogero--Moser systems of particles carrying spin 1/2. At special value of the coupling constant we propose the ansatz which allows one to get meromorphic solutions with two arbitrary parameters. They are quantiz

  16. Lode Wylleman

    The class of gravito-electric, algebraically general, rotating `silent' dust space-times is studied. The main invariant properties are deduced. The number $t_0$ of functionally independent zero-order Riemann invariants satisfies $1\leq t_0\leq 2$ and special attention is given to the subclass $t_0=1$. Whereas there are no $Λ$-term limits comprised in the

  17. J. T. Mendonça, B. Thidé, J. E. S. Bergman, S. M. Mohammadi

    We study theoretically the exchange of angular momentum between a photon beam and a plasma vortex, and demonstrate the possible excitation of photon angular momentum states in a plasma. This can be relevant to laboratory and space plasma diagnostics; radio astronomy self-calibration; and generating photon angular momentum beams. A static plasma perturbation

  18. D0 Collaboration, V. M. Abazov

    We present a measurement of the forward-backward charge asymmetry ($A_{FB}$) in $p\bar{p} \to Z/γ^{*}+X \to e^+e^-+X$ events at a center-of-mass energy of 1.96 TeV using 1.1 fb$^{-1}$ of data collected with the D0 detector at the Fermilab Tevatron collider. $A_{FB}$ is measured as a function of the invariant mass of the electron-positron pair, and found to b

  19. Markus Reineke

    A factorization formula for certain automorphisms of a Poisson algebra associated to a quiver is proved, which involves framed versions of moduli spaces of quiver representations. This factorization formula is related to wall-crossing formulas for Donaldson-Thomas type invariants of M. Kontsevich and Y. Soibelman.

  20. Stefano Catani, Tanju Gleisberg, Frank Krauss, German Rodrigo

    We derive a duality relation between one-loop integrals and phase-space integrals emerging from them through single cuts. The duality relation is realized by a modification of the customary +i0 prescription of the Feynman propagators. The new prescription regularizing the propagators, which we write in a Lorentz covariant form, compensates for the absence of

  21. S. Favorov, L. Golinskii

    Let $E$ be a closed set on the unit circle. We find a Blaschke-type condition, optimal in a sense of the order, on the Riesz measure of a subharmonic function $v$ in the unit disk with a certain growth at the direction of $E$. In particular case when $E$ is a finite set, and $v=\log|f|$ with an analytic function $f$, our result agrees with the recent one by

  22. Dimitra Atri, Adrian L. Melott, Brian C. Thomas

    A variety of events such as gamma-ray bursts and supernovae may expose the Earth to an increased flux of high-energy cosmic rays, with potentially important effects on the biosphere. Existing atmospheric chemistry software does not have the capability of incorporating the effects of substantial cosmic ray flux above 10 GeV . An atmospheric code, the NASA-God

  23. Ed Seidewitz

    Earlier work presented a spacetime path formalism for relativistic quantum mechanics arising naturally from the fundamental principles of the Born probability rule, superposition, and spacetime translation invariance. The resulting formalism can be seen as a foundation for a number of previous parameterized approaches to relativistic quantum mechanics in the

  24. Pai-Yi Hsiao

    We study salt-induced charge overcompensation and charge inversion of flexible polyelectrolytes via computer simulations and demonstrate the importance of ion excluded volume. Reentrant condensation takes place when the ion size is comparable to monomer size, and happens in a middle region of salt concentration. In a high-salt region, ions can overcharge a c

  25. Hisaki Hatanaka, Kwei-Chou Yang

    We present a detailed study of $B\to K_1(1270) γ$ and $B\to K_1(1400) γ$ decays. Using the light-cone sum rule technique, we calculate the $B\to K_{1A} (1^3P_1)$ and $B\to K_{1B} (1^1P_1)$ tensor form factors, $T_1^{K_{1A}}(0)$ and $T_1^{K_{1B}}(0)$, where the contributions are included up to the first order in $m_{K_1}/m_b$. We resolve the sign ambiguity of

  26. Donal F. Connon

    Gencev has recently reported a closed form summation for an infinite series involving the harmonic numbers and the central binomial numbers. This note indicates a possible approach to the proof involving the dilogarithm function.

  27. Zhi-Rong Lin, Guo-Ping Guo, Tao Tu, Fei-Yun Zhu

    We propose an efficient method to generate cluster states in spatially separated double quantum dots with a superconducting transmission line resonator (TLR). When the detuning between the double-dot qubits transition frequency and the frequency of the full wave mode in the TLR satisfies some conditions, an Ising-like operator between arbitrary two separated

  28. Zhen Shao, Haijun Zhou

    The mutual influence of dynamics and structure is a central issue in complex systems. In this paper we study by simulation slow evolution of network under the feedback of a local-majority-rule opinion process. If performance-enhancing local mutations have higher chances of getting integrated into its structure, the system can evolve into a highly heterogeneo

  29. Nguyen Van Chau

    A non-zero constant Jacobian polynomial maps $F=(P,Q)$ of $\mathbb{C}^2$ is invertible if $P$ and $Q$ are rational polynomials.

  30. Prashanth Alluvada

    Through purposeful introduction of malicious transactions (tracking transactions) into randomly select nodes of a (database) graph, soiled and clean segments are identified. Soiled and clean measures corresponding those segments are then computed. These measures are used to repose the problem of critical database elements detection as an optimization problem

  31. M. R. Buitelaar, V. Kashcheyevs, P. J. Leek, V. I. Talyanskii

    We investigate charge pumping in carbon nanotube quantum dots driven by the electric field of a surface acoustic wave. We find that at small driving amplitudes, the pumped current reverses polarity as the conductance is tuned through a Coulomb blockade peak using a gate electrode. We study the behavior as a function of wave amplitude, frequency and direction

  32. Andrew J. Hanson, Ji-Ping Sha

    We present an explicit algorithm for tessellating the algebraic surfaces (real 4-manifolds) F(n) embedded in CP3 defined by the equation z0^n + z1^n + z2^n + z3^n = 0 in the standard homogeneous coordinates [z0, z1, z2, z3], where n is any positive integer. Note that F(4) in particular is a K3 surface. Our tessellation contains a minimal number of vertices,

  33. A. Mezentsev

    Gradual transformation of the epidermal stem cells to corneocytes involves a chain of chronologically well-arranged events that mostly stimulated locally by their neighbors. Cell diversity that observed during the differentiation through the different epidermal cell layers included the consisted changes of cell shape, intercellular contacts and proliferation

  34. Francesco Giacosa

    The two-photon decay of a light scalar quarkonium is evaluated in a local and a nonlocal approaches. It is shown that the two-photon decay, driven by a triangle quark-loop diagram, is smaller than 1 keV for a mass below 0.7 GeV.

  35. Matthias an der Heiden, Michel Sortais, Michael Scheutzow, Martin Reisslein

    Packet-switching WDM ring networks with a hotspot transporting unicast, multicast, and broadcast traffic are important components of high-speed metropolitan area networks. For an arbitrary multicast fanout traffic model with uniform, hotspot destination, and hotspot source packet traffic, we analyze the maximum achievable long-run average packet throughput,

  36. J. T. Mendonça, B. Thidé

    It is shown that an electron-neutrino beam, propagating in a background plasma, can be decomposed into orbital momentum (OAM) states, similar to the OAM photon states. Coupling between different OAM neutrino states, in the presence of a plasma vortex, is considered. We show that plasma vorticity can be transfered to the neutrino beam, which is relevant to th

  37. Alex E. Bernardini

    The general and explicit relation between the phase time and the dwell time for quantum tunneling of a relativistically propagating particle is investigated and quantified. In analogy with previously obtained non-relativistic results, it is shown that the group delay can be described in terms of the dwell time and a self-interference delay. Lessons concernin

  38. Van Vu

    We discuss a structural approach to subset-sum problems in additive combinatorics. The core of this approach are Freiman-type structural theorems, many of which will be presented through the paper. These results have applications in various areas, such as number theory, combinatorics and mathematical physics.

  39. Robi Peschanski

    String theory has been initially derived from motivations coming from strong interaction phenomenology,but its application faced deep conceptual and practical difficulties. The strong interactions found their theoretical foundation elsewhere, namely on QCD, the quantum gauge field theory of quarks and gluons. Recently, the Gauge/Gravity correspondence allowe

  40. Hirbod Assa

    In this work we study the Lebesgue property for convex risk measures on the space of bounded càdlàg random processes ($\mathcal{R}^\infty$). Lebesgue property has been defined for one period convex risk measures in \cite{Jo} and earlier had been studied in \cite{De} for coherent risk measures. We introduce and study the Lebesgue property for convex risk meas

  41. A. J. Duncan, I. V. Kazachkov, V. N. Remeslennikov

    In 1971 J. Stallings introduced a generalisation of amalgamated products of groups -- called a pregroup, which is a particular kind of a partial group. He defined the universal group U(P) of a pregroup P to be a universal object (in the sense of category theory) extending the partial operations on P to group operations on U(P). This turns out to be a versati

  42. C. F. Gallo, James Q. Feng

    Observations reveal that mature spiral galaxies consist of stars, gases and plasma approximately distributed in a thin disk of circular shape, usually with a central bulge. The rotation velocities quickly increase from the galactic center and then achieve a constant velocity from the core to the periphery. The basic dynamic behavior of a mature spiral galaxy

  43. Victor A. Gopar

    The density of the transmission eigenvalues of Pb nano-contacts has been estimated recently in mechanically controllable break-junction experiments. Motivated by these experimental analyses, here we study the evolution of the density of the transmission eigenvalues with the disorder strength and the number of channels supported by the ballistic constriction

  44. Roberto Contino

    I review the current experimental bounds and theoretical predictions for different kinds of heavy neutral vector bosons.

  45. Diego Conti

    We introduce the C++ library Wedge, based on GiNaC, for symbolic computations in differential geometry. We show how Wedge makes it possible to use the language C++ to perform such computations, and illustrate some advantages of this approach with explicit examples. In particular, we describe a short program to determine whether a given linear exterior differ

  46. Vitor Araujo, Marcelo Viana

    The theory of uniformly hyperbolic dynamical systems was initiated in the 1960's (though its roots stretch far back into the 19th century) by S. Smale, his students and collaborators, in the west, and D. Anosov, Ya. Sinai, V. Arnold, in the former Soviet Union. It came to encompass a detailed description of a large class of systems, often with very compl

  47. P. A. Maksym, Y. Nishi, D. G. Austing, T. Hatano

    An accurate model of a vertical pillar quantum dot is described. The full three dimensional structure of the device containing the dot is taken into account and this leads to an effective two dimensional model in which electrons move in the two lateral dimensions, the confinement is parabolic and the interaction potential is very different from the bare Coul

  48. Y. Murakami, J. Kono

    We have studied emission properties of high-density excitons in single-walled carbon nanotubes through nonlinear photoluminescence excitation spectroscopy. As the excitation intensity was increased, all emission peaks arising from different chiralities showed clear saturation in intensity. Each peak exhibited a saturation value that was independent of the ex

  49. I. Zivkovic, V. P. S. Awana, H. Berger

    We have performed an investigation of the nonlinear magnetic response in ruthenocuprates. A negative, diverging-like peak at the main magnetic transition T_N in RuSr2RECu2O8 (RE = Gd, Y) indicates a possible canted antiferromagnetic order. Another well defined feature above T_N points to a blocking of superparamagnetic particles through the T^(-3) dependence

  50. Zhongzhi Zhang, Shuigeng Zhou, Zou Tao, Guisheng Chen

    In contrast to the conventional wisdom that scale-free networks are prone to epidemic propagation, in the paper we present that disease spreading is inhibited in fractal scale-free networks. We first propose a novel network model and show that it simultaneously has the following rich topological properties: scale-free degree distribution, tunable clustering

  51. K. Nagata, A. Hosaka, V. Dmitrasinovic

    We investigate the interactions and chiral properties of the four spin-$\thalf$-baryons : $N^-(D_{13})$, $N^+(P_{13})$, $Δ^+(P_{33})$ and $Δ^-(D_{33})$ together with the nucleon. We construct the $SU(2)_R \times SU(2)_L$ invariant interactions between the spin-$\half$ and -$\thalf$ baryons with the aid of a new, specially developed spin and isospin projectio

  52. Anton Mellit

    Higher Green functions are real-valued functions of two variables on the upper half plane which are bi-invariant under the action of a congruence subgroup, have logarithmic singularity along the diagonal, but instead of the usual equation $Δf=0$ we have equation $Δf = k(1-k) f$. Here $k$ is a positive integer. Properties of these functions are related to the

  53. C. N. Ragiadakos

    The dynamics of a four dimensional generally covariant modified SU(N) Yang-Mills action, which depends on the complex structure of spacetime and not its metric, is studied. A general solution of the complex structure integrability conditions is found in the context of the G{2,2) Grassmannian manifold, which admits a global SL(4,C) symmetry group. A convenien

  54. H. Leutwyler

    The first part of this report reviews recent developments at the interface between lattice work on QCD with light dynamical quarks, effective field theory and low energy precision experiments. Then I discuss how dispersion theory can be used to analyze the low energy structure of the $ππ$ scattering amplitude in a model independent manner. This leads to an e

  55. K. G. Sargsyan

    A generalization of the Yang-Lee and Fisher zeros on far-from-equilibrium systems coupled with two thermal baths is proposed. The Yang-Lee zeros were obtained for minimal models which exhibit complicated behavior in the context of the partition function zeros and provide an analitycal treatment. This type of models may be considered as a simplest one and ana

  56. Tao Han

    The LHC will be a top-quark factory. With 80 million pairs of top quarks and an additional 34 million single tops produced annually at the designed high luminosity, the properties of this particle will be studied to a great accuracy. The fact that the top quark is the heaviest elementary particle in the Standard Model with a mass right at the electroweak sca

  57. Y. Pomeau, M. Le Berre, P. Guyenne, S. Grilli

    Wave-breaking is studied analytically first and the results are compared with accurate numerical simulations of 3D wave-breaking. We focus on the time dependence of various quantities becoming singular at the onset of breaking. The power laws derived from general arguments and the singular behavior of solutions of nonlinear hyperbolic differential equations

  58. Andras Lorincz, Melinda Kiszlinger, Gabor Szirtes

    In this paper we explain the strikingly regular activity of the 'grid' cells in rodent dorsal medial entorhinal cortex (dMEC) and the spatially localized activity of the hippocampal place cells in CA3 and CA1 by assuming that the hippocampal region is constructed to support an internal dynamical model of the sensory information. The functioning of th

  59. I. S. Tupitsyn, A. Kitaev, N. V. Prokof'ev, P. C. E. Stamp

    We report a new type of multicritical point that arises from competition between the Higgs and confinement transitions in a Z_2 gauge system. The phase diagram of the 3d gauge Higgs model has been obtained by Monte-Carlo simulation on large (up to 60^3) lattices. We find the transition lines continue as 2nd-order until merging into a 1st-order line. These fi

  60. P. N. Timonin, G. Y. Chitov

    The one-dimensional kinetic contact process with parallel update is introduced and studied by Monte Carlo simulations. This process is proposed to describe the plant population replication and epidemic disease spreading among them. The phase diagram of the model features the line of the second order transitions between absorbing and active phases. The numeri

  61. Natalia Ptitsyna, Stephen P. Shipman, Stephanos Venakides

    We investigate Fano-type anomalous transmission of energy of plane waves across lossless slab scatterers with periodic structure in the presence of non-robust guided modes. Our approach is based on rigorous analytic perturbation of the scattering problem near a guided mode and applies to very general structures, continuous and discrete.

  62. Y. Pomeau, M. Le Berre

    The intensity of classical bright solitons propagating in linearly coupled identical fibers can be distributed either in a stable symmetric state at strong coupling or in a stable asymmetric state if the coupling is small enough. In the first case, if the initial state is not the equilibrium state, the intensity may switch periodically from fiber to fiber, w

  63. Zbigniew Palmowski, Martijn Pistorius

    We derive the exact asymptotics of $P(\sup_{u\leq t}X(u) > x)$ if $x$ and $t$ tend to infinity with $x/t$ constant, for a Lévy process $X$ that admits exponential moments. The proof is based on a renewal argument and a two-dimensional renewal theorem of Höglund (1990).

  64. Christof Geiss, Bernard Leclerc, Jan Schröer

    We use the representation theory of preprojective algebras to construct and study certain cluster algebras related to semisimple algebraic groups.

  65. A. Morozov

    Review of remarkable progress in evaluating of NSR superstring measures, originated by E.D'Hoker and D.Phong. These recent results are presented in the old-fashioned form, which allows to highlight the options that have been overlooked in original considerations in late 1980's.

  66. Cécile Ané

    The asymptotic behavior of estimates and information criteria in linear models are studied in the context of hierarchically correlated sampling units. The work is motivated by biological data collected on species where autocorrelation is based on the species' genealogical tree. Hierarchical autocorrelation is also found in many other kinds of data, such as f

  67. Mihail Poplavskyi

    We give a proof of universality in the bulk of spectrum of unitary matrix models, assuming that the potential is globally $C^{2}$ and locally $C^{3}$ function. The proof is based on the determinant formulas for correlation functions in terms of polynomials orthogonal on the unit circle. We do not use asymptotics of orthogonal polynomials. We obtain the $sin$

  68. Peter M. Akhmetiev, Matija Cencelj, Dušan D. Repovš

    We prove that no $14$-connected (resp. $30$-connected) stably parallelizable manifold $N^{30}$ (resp. $N^{62}$) of dimension $30$ (resp. $62$) with the Arf-Kervaire invariant 1 can be smoothly embedded into $\mathbb{R}^{36}$ (resp. $\mathbb{R}^{83}$).

  69. Alex Buchel

    We present evidence for the universality of the shear viscosity of conformal gauge theory plasmas beyond infinite coupling. We comment of subtleties of computing the shear viscosity in effective models of gauge/gravity correspondence rather than in string theory.

  70. M. Martin-Benito, G. A. Mena Marugan, T. Pawlowski

    We analyze the loop quantization of the family of vacuum Bianchi I spacetimes, a gravitational system whose classical solutions describe homogeneous anisotropic cosmologies. We rigorously construct the operator that represents the Hamiltonian constraint, showing that the states of zero volume completely decouple from the rest of quantum states. This fact ens

  71. G. Susinder Rajan, B. Sundar Rajan

    For point to point multiple input multiple output systems, Dayal-Brehler-Varanasi have proved that training codes achieve the same diversity order as that of the underlying coherent space time block code (STBC) if a simple minimum mean squared error estimate of the channel formed using the training part is employed for coherent detection of the underlying ST

  72. S. A. Alavi

    Thermodynamics of quasianti-Hermitian quaternionic systems with constant number of particles in equilibrium is studied. A toy model is introduced and the physically relevant quantities are derived. The energy fluctuation which shows that for large N the relative r.m.s fluctuation in the values of E is quite negligible is derived. The negative temperature for

  73. Stephanie Deboeuf, Mokhtar Adda-Bedia, Arezki Boudaoud

    The packing of elastic sheets is investigated in a quasi two-dimensional experimental setup: a sheet is pulled through a rigid hole acting as a container, so that its configuration is mostly prescribed by the cross-section of the sheet in the plane of the hole. The characterisation of the packed configuration is made possible by using refined image analysis.

  74. Roman V. Baluev

    The full set of published radial velocity data (52 measurements from Keck + 58 ones from ELODIE + 17 ones from CORALIE) for the star HD37124 is analysed. Two families of dynamically stable high-eccentricity orbital solutions for the planetary system are found. In the first one, the outer planets c and d are trapped in the 2/1 mean-motion resonance. The secon

  75. Alexander Afriat, Ermenegildo Caccese

    We first see that the inertia of Newtonian mechanics is absolute and troublesome. General relativity can be viewed as Einstein's attempt to remedy, by making inertia relative, to matter---perhaps imperfectly though, as at least a couple of freedom degrees separate inertia from matter in his theory. We consider ways the relationist (for whom it is of cour

  76. Ester Livshits, Roi Baer

    It is known for quite some time that approximate density functional (ADF) theories fail disastrously when describing the dis-sociative symmetric radical cations R2+. Considering this dissociation limit, previous work has shown that Hartree-Fock (HF) theory favors the R+1--R0 charge distribution while DF approximations favor the R+0.5 -- R+0.5. Yet, general q

  77. Anthony P. Metcalfe, Neil O'Connell, Jon Warren

    When two Markov operators commute, it suggests that we can couple two copies of one of the corresponding processes. We explicitly construct a number of couplings of this type for a commuting family of Markov processes on the set of conjugacy classes of the unitary group, using a dynamical rule inspired by the RSK algorithm. Our motivation for doing this is t

  78. K. Omukai, R. Schneider, Z. Haiman

    Primordial gas in protogalactic dark matter (DM) halos with virial temperatures Tvir > 10^4 K begins to cool and condense via atomic hydrogen. Provided this gas is irradiated by a strong ultraviolet (UV) flux and remains free of H2 and other molecules, it has been proposed that the halo with Tvir ~10^4 K may avoid fragmentation, and lead to the rapid formati

  79. Miguel A. Herrada, Alfonso M. Ganan-Calvo, Antonio Ojeda-Monge, Benjamin Bluth

    The liquid cone-jet mode can be produced upon stimulation by a co-flowing gas sheath. Most applications deal with the jet breakup, leading to either of two droplet generation regimes: jetting and dripping. The cone-jet flow pattern is explored by direct axisymmetric VOF numerical simulation; its evolution is studied as the liquid flow-rate is increased aroun

  80. Hui Lin, Cheng Hao, Xiao Wang, Qiang Yuan

    In this paper, we use a set of observational $H(z)$ data (OHD) to constrain the $Λ$CDM cosmology. This data set can be derived from the differential ages of the passively evolving galaxies. Meanwhile, the $\mathcal {A}$-parameter, which describes the Baryonic Acoustic Oscillation (BAO) peak, and the newly measured value of the Cosmic Microwave Background (CM

  81. So-Young Baek, Yong Wook Cheong, Yoon-Ho Kim

    We propose and demonstrate a linear optical device which deterministically performs optimal quantum measurement or minimum disturbance measurement on a single-photon polarization qubit with the help of an ancillary path qubit introduced to the same photon. We show theoretically and experimentally that this device satisfies the minimum disturbance measurement

  82. Francisco Gilabert, Jean-Noël Roux, Antonio Castellanos

    The quasistatic behavior of a simple 2D model of a cohesive powder under isotropic loads is investigated by Discrete Element simulations. The loose packing states, as studied in a previous paper, undergo important structural changes under growing confining pressure P, while solid fraction Φirreversibly increases by large amounts. The system state goes throug

  83. Yasuhiro Abe

    We consider (2+1)-dimensional Yang-Mills theory on $S^1 \times S^1 \times {\bf R}$ in the framework of a Hamiltonian approach developed by Karabali, Kim and Nair. The deconfining limit in the theory can be discussed in terms of one of the $S^1$ radii of the torus ($S^1 \times S^1$), while the other radius goes to infinity. We find that the limit agrees with

  84. Yoshiko Kanada-En'yo, Daisuke Jido

    A $\bar{K}\bar{K}N$ system with $I=1/2$ and $J^P=1/2^+$ is investigated with non-relativistic three-body calculations by using effective $\bar{K}N$ and $\bar K \bar K$ interactions. The present investigation suggests that a weakly bound state for the $\bar{K}\bar{K}N$ system can be formed below the two-body threshold of $\bar{K}$ and quasibound $\bar{K}N$ wi

  85. A. Stern

    We construct perturbative static solutions to the classical field equations of noncommutative U(1) gauge theory for the three cases: a) space-time noncommutativity, b) space-space noncommutativity and c) both a) and b). The solutions tend to the Coulumb solution at spatial infinity and are valid for intermediate values of the radial coordinate $r$. They yiel

  86. Chia-Chun Lu, Guey-Lin Lin

    Motivated by recent Pierre Auger result on the correlation of the highest-energy cosmic rays with the nearby active galactic nuclei, we explore possible ultrahigh energy cosmic ray (UHECR) source distributions and their effects on GZK horizons. Effects on GZK horizons by local over-density of UHECR sources are examined carefully with constraints on the degre

  87. Taras Radul, Dušan Repovš

    We investigate some topological properties of a normal functor $H$ introduced earlier by Radul which is a certain functorial compactification of the Hartman-Mycielski construction $HM$. We show that $H$ is open and find the condition when $HX$ is an absolute retract homeomorphic to the Tychonov cube.

  88. Rui Dilao

    In 1665, Christiaan Huygens reported the observation of the synchronization of two pendulum clocks hanged on the wall of his workshop. After synchronization, the clocks swung exactly in the same frequency and $180^{o}$ out of phase -- anti-phase synchronization. Here, we propose and analyze a new interaction mechanism between oscillators leading to exact ant

  89. Andrei Galiautdinov, John M. Martinis

    We introduce a suit of simple entangling protocols for generating tripartite GHZ and W states in systems with anisotropic exchange interaction g(XX+YY)+g&#39;ZZ. An interesting example is provided by macroscopic entanglement in Josephson phase qubits with capacitive (g&#39;=0) and inductive (0<|g&#39;/g|<0.1) couplings.

  90. C. Chryssomalakos, H. Hernandez, D. Gelbwaser-Klimovsky, E. Okon

    We show that quantum particles constrained to move along curves undergoing cyclic deformations acquire, in general, geometric phases. We treat explicitly an example, involving particular deformations of a circle, and ponder on potential applications.

  91. Ray Cavalcante, Todor D. Todorov

    We present a simple yet rigorous theory of integration that is based on two axioms rather than on a construction involving Riemann sums. With several examples we demonstrate how to set up integrals in applications of calculus without using Riemann sums. In our axiomatic approach even the proof of the existence of the definite integral (which does use Riemann

  92. Christian Schmid, Nikolai Kiesel, Wiesław Laskowski, Witlef Wieczorek

    The variety of multi-partite entangled states enables numerous applications in novel quantum information tasks. In order to compare the suitability of different states from a theoretical point of view classifications have been introduced. Accordingly, here we derive criteria and demonstrate how to experimentally discriminate an observed state against the one

  93. Yujiro Kawamata

    The purpose of this note is to review an algebraic proof of the finite generation theorem due to Birkar-Cascini-Hacon-McKernan whose method is based on the Minimal Model Program. A survey article for Current Development in Mathematics 2007.

  94. Yujiro Kawamata

    A survey article for AMS Summer Institute at Seattle in 2005.

  95. A. Ramazani-Moghaddam-Arani, Amir-Ahmadi, A. D. Bacher, C. D. Bailey

    Observables in elastic proton-deuteron scattering are sensitive probes of the nucleon-nucleon interaction and three-nucleon force effects. The present experimental data base for this reaction is large, but contains a large discrepancy between data sets for the differential cross section taken at 135 MeV/nucleon by two experimental research groups. This paper

  96. Bohui Chen, An-Min Li, Qi Zhang, Guosong Zhao

    In this paper, we study the symplectic geometry of singular conifolds of the finite group quotient $$ W_r=\{(x,y,z,t)|xy-z^{2r}+t^2=0 \}/μ_r(a,-a,1,0), r\geq 1, $$ which we call orbi-conifolds. The related orbifold symplectic conifold transition and orbifold symplectic flops are constructed. Let $X$ and $Y$ be two symplectic orbifolds connected by such a flo

  97. Bohui Chen, An-Min Li, Guosong Zhao

    We prove that the orbifold quantum ring is preserved under singular symplectic flops. Hence we verify Ruan&#39;s conjecture for this case.

  98. G. Valyavin, G. A. Wade, S. Bagnulo, T. Szeifert

    We present and interpret new spectropolarimetric observations of the magnetic white dwarf WD 1953-011. Circular polarization and intensity spectra of the H$α$ spectral line demonstrate the presence of two-component magnetic field in the photosphere of this star. The geometry consists of a weak, large scale component, and a strong, localized component. Analyz

  99. David Langlois, Sebastien Renaux-Petel, Daniele A. Steer, Takahiro Tanaka

    We study Dirac-Born-Infeld (DBI) inflation models with multiple scalar fields. We show that the adiabatic and entropy modes propagate with a common effective sound speed and are thus amplified at the sound horizon crossing. In the small sound speed limit, we find that the amplitude of the entropy modes is much higher than that of the adiabatic modes. We show

  100. Donal F. Connon

    This short note deals with some applications of the Beta function