May 2006 arXiv papers — page 28

Y. L. Zuev, I. Hetel, T. R. Lemberger

The preformed-pairs theory of pseudogap physics in high-$T_C$ superconductors predicts a nonanalytic $T$-dependence for the $ab$-plane superfluid fraction, $ρ_S$, at low temperatures in underdoped cuprates. We report high-precision measurements of $ρ_S(T)$ on severely underdoped YBa$_2$Cu$_3$O$_{6+x}$ and Y$_{0.8}$Ca$_{0.2}$Ba$_2$Cu$_3$O$_{6+x}$ films. At lo

Mitsuhiro Arikawa, Michael Karbach, Gerhard Muller, Klaus Wiele

The exact one-to-one mapping between (spinless) Jordan-Wigner lattice fermions and (spin-1/2) spinons is established for all eigenstates of the one-dimensional s = 1=2 XX model on a lattice with an even or odd number N of lattice sites and periodic boundary conditions. Exact product formulas for the transition rates derived via Bethe ansatz are used to calcu

N. T. Bagraev, N. G. Galkin, W. Gehlhoff, L. E. Klyachkin

We present the first findings of the spin transistor effect in the Rashba gate-controlled ring embedded in the p-type self-assembled silicon quantum well that is prepared on the n-type Si (100) surface. The coherence and phase sensitivity of the spin-dependent transport of holes are studied by varying the value of the external magnetic field and the bias vol

N. Regnault, C. C. Chang, Th. Jolicoeur, J. K. Jain

Ultracold neutral bosons in a rapidly rotating atomic trap have been predicted to exhibit fractional quantum Hall-like states. We describe how the composite fermion theory, used in the description of the fractional quantum Hall effect for electrons, can be applied to interacting bosons. Numerical evidence supporting the formation of composite fermions, each

Maria G. Fyta, Pantelis C. Kelires

Several interesting phenomena are observed when materials are put under pressure. The goal is to achieve modification and control over their mechanical and electronic (conduction) properties. Within this spirit, we have recently focused our attention into how carbon nanostructures respond to hydrostatic pressure. We performed Monte Carlo simulations with the

Xavier Illa, Eduard Vives

We have defined pinning fields as those random fields that keep some of the magnetic moments unreversed in the region of negative external applied field during the demagnetizing process. An analysis of the statistical properties of such pinning fields is presented within the context of the Gaussian Random Field Ising Model (RFIM). We show that the average of

Eduard Vives, Xavier Illa, Antoni Planes

A simple lattice model that allows hysteresis loops with exchange bias to be reproduced is presented. The model is based on the metastable Random Field Ising model, driven by an external field, with synchronous local relaxation dynamics. The key ingredient of the model is that a certain fraction $f$ of the exchange constants between neighbouring spins is enh

Antonio Iovanella, Benedetto Scoppola, Elisabetta Scoppola

In this paper we introduce a new algorithm to study some NP-complete problems. This algorithm is a Markov Chain Monte Carlo (MCMC) inspired by the cavity method developed in the study of spin glass. We will focus on the maximum clique problem and we will compare this new algorithm with several standard algorithms on some DIMACS benchmark graphs and on random

M. Daghofer, P. Horsch, G. Khaliullin

We present a numerical treatment of a spin-orbital polaron model for Na_xCoO_2 at small hole concentration (0.7 < x < 1). We demonstrate how the polarons account for the peculiar magnetic properties of this layered compound: They explain the large susceptibility; their internal degrees of freedom lead both to a negative Curie-Weiss temperature and yet to a f

M. Borromeo, S. Giusepponi, F. Marchesoni

The one dimensional motion of a massless Brownian particle on a symmetric periodic substrate can be rectified by re-injecting its driving noise through a realistic recycling procedure. If the recycled noise is multiplicatively coupled to the substrate, the ensuing feed-back system works like a passive Maxwell&#39;s daemon, capable of inducing a net current t

onattu D. Jayakumar, Iyyani K. Gopalakrishnan, Shailendra K. Kulshreshtha

We have developed a simple, surfactant assisted synthesis route for the preparation, in gram quantities, of Co and Li doped ZnO nanocrystalline samples showing robust room temperature ferromagnetism. Our studies show that RTF is intrinsic to Zn0.85Co0.05Li0.10O and not due to any segregated secondary phases. In addition, it has been shown that the defects pl

P. Fröbrich, P. J. Kuntz

This contribution describes the reorientation of the magnetization of thin ferromagnetic Heisenberg films as function of the temperature and/or an external field. Working in a rotating frame allows an exact treatment of the single-ion anisotropy when going to higher-order Green&#39;s functions. Terms due to the exchange interaction are treated by a generaliz

Luc Favre, Véronique Dupuis, Estela Bernstein, Patrice Mélinon

In this present work, we report a structural and magnetic study of mixed Co58Pt42 clusters. MgO, Nb and Si matrix can be used to embed clusters, avoiding any magnetic interactions between particles. Transmission Electron Microscopy (TEM) observations show that Co58Pt42 supported isolated clusters are about 2nm in diameter and crystallized in the A1 fcc chemi

Philippe Leininger, J. -P. Rueff, J. -M. Mariot, A. Yaresko

The electronic properties of Co in bulk Na0.7CoO2 and the superconducting hydrated compound Na0.35CoO2 - y H2O have been investigated by x-ray absorption spectroscopy (XAS) and resonant inelastic x-ray scattering (RIXS) using hard x-rays. The XAS spectra at the Co K-edge were measured in both compounds with two different polarization directions. The changes

M. Houzet, A. I. Buzdin

We analyze the enhancement of the superconducting critical temperature of superconducting/ferromagnetic bilayers due to the appearance of localized superconducting states in the vicinity of magnetic domain walls in the ferromagnet. We consider the case when the main mechanism of the superconductivity destruction via the proximity effect is the exchange field

J. S. Kim, K. -I. Goh, G. Salvi, E. Oh

Fractal scaling--a power-law behavior of the number of boxes needed to tile a given network with respect to the lateral size of the box--is studied. We introduce a new box-covering algorithm that is a modified version of the original algorithm introduced by Song et al. [Nature (London) 433, 392 (2005)]; this algorithm enables effective computation and easy i

M. Tasinkevych, S. Dietrich

Complete wetting of geometrically structured substrates by one-component fluids with long-ranged interactions is studied. We consider periodic arrays of rectangular or parabolic grooves and lattices of cylindrical or parabolic pits. We show that the midpoint interfacial heights within grooves and pits are related in the same way as for complete wedge and con

C. G. Yang, E. Ehrenfreund, Z. V. Vardeny

In a recent paper Segal et al. [1] attempted to explain the dynamics of spin 1/2 photoluminescence detected magnetic resonance (PLDMR) in films of a pi-conjugated polymer, namely a soluble de-rivative of poly(phenylene-vinylene) [MEH-PPV] using a model (dubbed TPQ), in which the PLDMR is due to spin dependent triplet-polaron interactions that reduce the pola

M. Koskinen, S. M. Reimann, J. -P. Nikkarila, M. Manninen

The exact diagonalization technique is used to study many-particle properties of interacting electrons with spin, confined in a two-dimensional harmonic potential. The single-particle basis is limited to the lowest Landau level. The results are analyzed as a function of the total angular momentum of the system. Only at angular momenta corresponding to the fi

Song-Ho Chong

We present theoretical investigation on the high-frequency collective dynamics in liquids and glasses at microscopic length scales and terahertz frequency region based on the mode-coupling theory for ideal liquid-glass transition. We focus on recently investigated issues from inelastic-X-ray-scattering and computer-simulation studies for dynamic structure fa

Chitoshi Yasuda, Daisuke Kinouchi, Kenn Kubo

We study the spin wave in the S=1/2 multiple-spin exchange model on a triangular lattice in a magnetic field within the linear spin-wave theory. We take only two-, three- and four-spin exchange interactions into account and restrict ourselves to the region where a coplanar three-sublattice state is the mean-field ground state. We found that the Y-shape groun

Takayuki Makino, A. Tsukazaki, A. Ohtomo, M. Kawasaki

We have grown nitrogen-doped ZnO films grown by two kinds of epitaxial methods on lattice-matched ScAlMgO$_4$ substrates. We measured the photoluminescence (PL) of the two kinds of ZnO:N layers in the donor-acceptor-pair transition region. The analysis of excitation-intensity dependence of the PL peak shift with a fluctuation model has proven that our observ

A. Zazunov, R. Egger, C. Mora, T. Martin

Nonequilibrium electronic transport through a molecular level weakly coupled to a single coherent phonon/vibration mode has been studied for superconducting leads. The Keldysh Green function formalism is used to compute the current for the entire bias voltage range. In the subgap regime, Multiple Andreev Reflection (MAR) processes accompanied by phonon emiss

Carsten Hutter, Alexander Shnirman, Yuriy Makhlin, Gerd Schön

We analyze the coupling of qubits mediated by a tunable and fast element beyond the adiabatic approximation. The nonadiabatic corrections are important and even dominant in parts of the relevant parameter range. As an example, we consider the tunable capacitive coupling between two charge qubits mediated by a gated Josephson junction, as suggested by Averin

D. C. Lovelady, H. M. Harper, I. E. Brodsky, D. A. Rabson

The variety of magnetic phases observed in rare-earth heterostructures at low temperatures \cite{Jehan}, such as Ho/Y, may be elucidated by an ANNNI-like model Hamiltonian. In previous work modelling bulk Ho \cite{Seno}, such a Hamiltonian with a one-dimensional parameter space produced a single multiphase point. In contrast, the parameter space of the heter

Marjorie Creux, Adeline Crepieux, Thierry Martin

The measurement of finite frequency noise cross-correlations represents an experimental challenge in mesoscopic physics. Here we propose a generalisation of the resonant LC circuit setup of Lesovik and Loosen which allow to probe directly such cross-correlations by measuring the charge fluctuations on the plates of a capacitor. The measuring circuit collects

Hui Hu, Xia-Ji Liu, Peter D. Drummond

We present a theory for a superfluid Fermi gas near the BCS-BEC crossover, including pairing fluctuation contributions to the free energy similar to that considered by Nozieres and Schmitt-Rink for the normal phase. In the strong coupling limit, our theory is able to recover the Bogoliubov theory of a weakly interacting Bose gas with a molecular scattering l

Deng Xin-Fa, Ma Xin-Sheng, He Con-Gen, Luo Cheng-Hong

We have investigated the Holmberg effect of Main galaxy pairs of the SDSS Data Release 4 (SDSS4). It is found that except i-z color the color indices between the two components of Main galaxy pairs clearly have significantly larger correlation coefficients. Further analyses also show that the Holmberg Effect of galaxies not only depends on the color indices

Carlo Luciano Bianco, Remo Ruffini

We present the exact analytic expressions to compute, assuming the emitted Gamma-Ray Burst (GRB) radiation is not spherically symmetric but is confined into a narrow jet, the value of the detector arrival time at which we start to &#34;see&#34; the sides of the jet, both in the fully radiative and adiabatic regimes. We obtain this result using our exact anal

Matthew D. Duez, Yuk Tung Liu, Stuart L. Shapiro, Masaru Shibata

We study the effects of magnetic fields on the evolution of differentially rotating neutron stars, which can form in stellar core collapse or binary neutron star coalescence. Magnetic braking and the magnetorotational instability (MRI) both redistribute angular momentum; the outcome of the evolution depends on the star&#39;s mass and spin. Simulations are ca

Martin Durant, Marten H. van Kerkwijk

We have analyzed both archival and new infrared imaging observations of the field of the Anomalous X-ray Pulsar 1RXS J170849.0-400910, in search of the infrared counterpart. This field has been previously investigated, and one of the sources consistent with the position of the AXP suggested as the counterpart. We, however, find that this object is more likel

Desika Narayanan, Craig Kulesa, Alan Boss, Christopher K. Walker

In the era of high resolution submillimeter interferometers, it will soon be possible to observe the neutral circumstellar medium directly involved in gas giant planet (GGP) formation at physical scales previously unattainable. In order to explore possible signatures of gas giant planet formation via disk instabilities, we have combined a 3D, non-local therm

Barry Y. Welsh, Jonathan M. Wheatley, Mark Seibert, Stanley E. Browne

We present the preliminary results from implementing a new software tool that enables inspection of time-tagged photon data for the astronomical sources contained within individual GALEX ultraviolet images of the sky. We have inspected the photon data contained within 1802 GALEX images to reveal rapid, short-term (<500 sec) UV source variability in the form

Katherine L. Rhode

I present selected results from a wide-field CCD survey of the globular cluster systems of giant galaxies, including showing how measurements of the specific frequency of metal-poor globular clusters can constrain the redshift of their formation.

I. Navarro, K. Van Acoleyen

We consider modifications of General Relativity obtained by adding the logarithm of some curvature invariants to the Einstein-Hilbert action. These non-linear actions can explain the late-time acceleration of the universe giving an expansion history that differs from that of a pure cosmological constant. We show that they also modify the Newtonian potential

Nicholas D. Morgan, Christopher S. Kochanek, Emilio E. Falco, Xinyu Dai

We have measured the three time delays for the quadruple gravitational lens RX J1131-1231 using two seasons of monitoring data. The short delays between cusp images are A-B = 11.98 +1.52,-1.27 days and A-C = 9.61 +1.97,-1.57 days. The long A-D delay for the counter image is not as precisely determined because of the season gaps, but the data suggest a delay

V. Suleimanov, J. Madej, J. J. Drake, T. Rauch

We re-examine the effects of Compton scattering on the emergent spectra of hot DA white dwarfs in the soft X-ray range. Earlier studies have implied that sensitive X-ray observations at wavelengths $λ< 50$ Åmight be capable of probing the flux deficits predicted by the redistribution of electron-scattered X-ray photons toward longer wavelengths. We adopt two

Ahmet Mecit Öztaş, Michael L. Smith

A model is presented allowing calculation of energy and matter distribution in the Universe after expansion from singularity without introduction of expansion energy. Beginning with Fick&#39;s law of diffusion, we solve the Bessel function for spherical systems during expansion, presuming isotropic matter distribution in the Hubble flow. This function can be

Daniel Angerhausen, Alfred Krabbe, Christof Iserlohe

We present first results of an exploratory study to use integral field spectroscopy to observe extrasolar planets. We focus on transiting &#34;Hot Jupiters&#34; and emphasize the importance of observing strategy and exact timing. We demonstrate how integral field spectroscopy compares with other spectroscopic techniques currently applied. We have tested our

E. M. Drobyshevski

The experiments of 2005 aimed at detection of low-velocity (~10-15 km s-1) daemons falling on to the Earth&#39;s surface from Near-Earth, Almost Circular Heliocentric Orbits (NEACHOs) have corroborated once more the existence of the March maximum in their flux by raising its confidence level to 99.99%. In addition, these experiments permitted us to identify

Jean-Philippe Uzan

Using a general classification of dark enegy models in four classes, we discuss the complementarity of cosmological observations to tackle down the physics beyond the acceleration of our universe. We discuss the tests distinguishing the four classes and then focus on the dynamics of the perturbations in the Newtonian regime. We also exhibit explicitely model

Hiroshi Nagai, Makoto Inoue, Keiichi Asada, Seiji Kameno

We present a study of the kinematic and spectral ages of the Gigahertz-Peaked Spectrum (GPS) source CTD~93. Measurements of the hot spot separation over 8.5 yr show evidence of an increase. The separation rate along the source axis is 0.34$\pm0.11c$ (H$_{0}$=72 km s$^{-1}$ Mpc$^{-1}$), which results in a kinematic age of 2200$\pm$700 yr. Assuming that two ho

W. J. Tango, J. Davis, M. J. Ireland, C. Aerts

The triple system HD158926 (lambda Sco) has been observed interferometrically with the Sydney University Stellar Interferometer and the elements of the wide orbit have been determined. These are significantly more accurate than the previous elements found spectroscopically. The inclination of the wide orbit is consistent with the inclination previously found

John W. Grula

How photosynthesis by Precambrian cyanobacteria oxygenated Earth&#39;s biosphere remains incompletely understood. Here it is argued that the oxic transition, which took place between approximately 2.3 and 0.5 Gyr ago, required a great proliferation of cyanobacteria, and this in turn depended on their ability to fix nitrogen via the nitrogenase enzyme system.

Dmitri A. Uzdensky, Russell M. Kulsrud

A quadrupole pattern of the out-of-plane component of the magnetic field inside a reconnection region is seen as an important signature of the Hall-magnetohydrodynamic (Hall-MHD) regime of reconnection. It has been first observed in numerical simulations and just recently confirmed in the MRX (Magnetic Reconnection Experiment) [M. Yamada, H. Ji, S. Hsu, T. C

Yufang Xi, Edmund M. Yeh

We present a unified analytical framework within which power control, rate allocation, routing, and congestion control for wireless networks can be optimized in a coherent and integrated manner. We consider a multi-commodity flow model with an interference-limited physical-layer scheme in which power control and routing variables are chosen to minimize the s

Ioan Bejenaru

We study the global well-posedness theory for the Schrödinger Maps equation. We work in $n+1$ dimensions, for $n \geq 3$, and prove a local well-posedness for small initial data in $\dot{B}^{\frac{n}{2}}_{2,1}$.

Claudia de Rham, Andrew J. Tolley

We propose a simple higher-derivative braneworld gravity model which contains a stable accelerating branch, in the absence of cosmological constant or potential, that can be used to describe the late time cosmic acceleration. This model has similar qualitative features to that of Dvali-Gabadadze-Porrati, such as the recovery of four-dimensional gravity at su

Richard J. Mathar

Long-baseline interferometry detects fringes created by superposition of two beams of light collected by two telescopes pointing into a common direction. The external path difference generated by pointing away from the zenith is commonly compensated by adding a variable optical path length (delay) through air for one beam such that the optical path differenc

Domingos Soares

A critical reading of Lubin & Sandage's 2001 paper on the Tolman effect for the reality of the expansion of the universe clearly reveals that Sandage is far from winning the dispute with Hubble on the issue. After all the years, Hubble's doubt about the reality of the expansion remains as valid as Sandage's certainty expressed in a series of papers in the la

Debora Sijacki, Volker Springel

Most hydrodynamical simulations of galaxy cluster formation carried out to date have tried to model the cosmic gas as an ideal, inviscid fluid, where only a small amount of (unwanted) numerical viscosity is present, arising from practical limitations of the numerical method employed, and with a strength that depends on numerical resolution. However, the phys

Andreas Karch, Andy O&#39;Bannon

We use the AdS/CFT correspondence to perform a numerical study of a phase transition in strongly-coupled large-Nc N = 4 Super-Yang-Mills theory on a 3-sphere coupled to a finite number Nf of massive N = 2 hypermultiplets in the fundamental representation of the gauge group. The gravity dual system is a number Nf of probe D7-branes embedded in AdS_5 x S^5. We

Weiya Zhang, Mark G. Kuzyk

Using a generalized Gaussian beam decomposition method we determine the propagation of a Laguerre-Gaussian beam that has passed through a thin nonlinear optical Kerr medium. The orbital angular momentum per photon of the beam is found to be conserved while the component beams change. As an illustration of applications, we propose and demonstrate a z-scan exp

Ivan Horvath

In this series of articles we describe a systematic approach to studying QCD vacuum structure using the methods of lattice gauge theory. Our framework incorporates four major components. (i) The recently established existence of space-time order at all scales (fundamental structure) observed directly in typical configurations of regularized path-integral ens

H. W. Diehl, Daniel Grüneberg, M. A. Shpot

Systems described by $n$-component $ϕ^4$ models in a $\infty^{d-1}\times L$ slab geometry of finite thickness $L$ are considered at and above their bulk critical temperature $T_{c,\infty}$. The renormalization-group improved perturbation theory commonly employed to investigate the fluctuation-induced forces (``thermodynamic Casimir effect&#39;&#39;) in $d=4-

A. Schwarz, I. Shapiro

We define a superspace over a ring $R$ as a functor on a subcategory of the category of supercommutative $R$-algebras. As an application the notion of a $p$-adic superspace is introduced and used to give a transparent construction of the Frobenius map on $p$-adic cohomology of a smooth projective variety over the ring of $p$-adic integers.

Kazuo Habiro, Jean-Baptiste Meilhan

The purpose of the paper is twofold. First, we give a short proof using the Kontsevich integral for the fact that the restriction of an invariant of degree 2n to (n+1)-component Brunnian links can be expressed as a quadratic form on the Milnor mu-bar link-homotopy invariants of length n+1. Second, we describe the structure of the Brunnian part of the degree

Roberto D&#39;Agosta, Na Sai, Massimiliano Di Ventra

The electron current density in nanoscale junctions is typically several orders of magnitude larger than the corresponding one in bulk electrodes. Consequently, the electron-electron scattering rate increases substantially in the junction. This leads to local electron heating of the underlying Fermi sea in analogy to the local ionic heating that is due to th

A. Schwarz, I. Shapiro

The notion of a $p$-adic superspace is introduced and used to give a transparent construction of the Frobenius map on $p$-adic cohomology of a smooth projective variety over $\zp$ (the ring of $p$-adic integers), as well as an alternative construction of the crystalline cohomology of a smooth projective variety over $\fp$ (finite field with $p$ elements).

Roger Bielawski

We study the hyperkaehler geometry of a regular semisimple adjoint orbit of SL(k,C) via the algebraic geometry of the corresponding reducible spectral curve.

Piotr Pragacz, Andrzej Weber

Combining the Kazarian approach to Thom polynomials via classifying spaces of singularities with the Fulton-Lazarsfeld theory of numerical positivity for ample vector bundles, we show that the coefficients of various Schur function expansions of the Thom polynomials of stable and unstable singularities are nonnegative.

Alon E. Faraggi, Stefan Forste, Cristina Timirgaziu

We discuss heterotic strings on Z_2 x Z_2 orbifolds of non factorisable six-tori. Although the number of fixed tori is reduced as compared to the factorisable case, Wilson lines are still needed for the construction of three generation models. An essential new feature is the straightforward appearance of three generation models with one generation per twiste

A. V. Anisovich, A. V. Sarantsev

The cross sections for photo- and pion-induced production of baryon resonances and their partial decay widths to the two--body and multi--body final states are calculated in the framework of the operator expansion method. The approach is fully relativistic invariant, and it allows us to perform combined analyses of different reactions imposing directly the a

Ido Adam, Pietro Antonio Grassi, Luca Mazzucato, Yaron Oz

We construct non-critical pure spinor superstrings in two, four and six dimensions. We find explicitly the map between the RNS variables and the pure spinor ones in the linear dilaton background. The RNS variables map onto a patch of the pure spinor space and the holomorphic top form on the pure spinor space is an essential ingredient of the mapping. A basic

Eduardo J. Dubuc, Ross Street

We define the notion of 2-filtered 2-category and give an explicit construction of the bicolimit of a category valued 2-functor. A category considered as a trivial 2-category is 2-filtered if and only if it is a filtered category, and our construction yields a category equivalent to the category resulting from the usual construction of filtered colimits of c

Sheldon Stone

I discuss new results on absolute branching ratios of charm mesons into specific exclusive final states, Cabibbo suppressed decay rates, inclusive decays to $s\bar{s}$ mesons, limits on D^0 anti-D^0 mixing, CP violation and T violation. Preliminary results from CLEO-c now dominate the world average absolute branching fractions. For the most important normali

Wolfram Mobius, Richard A. Neher, Ulrich Gerland

Using a theoretical model for spontaneous partial DNA unwrapping from histones, we study the transient exposure of protein-binding DNA sites within nucleosomes. We focus on the functional dependence of the rates for site exposure and reburial on the site position, which is measurable experimentally and pertinent to gene regulation. We find the dependence to

A. Gallazzi, S. Charlot, J. Brinchmann, S. D. M. White

We exploit recent constraints on the ages and metallicities of early-type galaxies in the Sloan Digital Sky Survey (SDSS) to gain new insight into the physical origin of two fundamental relations obeyed by these galaxies: the colour-magnitude and the Mg2-sigmaV relations. Our sample consists of 26,003 galaxies selected from the SDSS DR2 on the basis of their

Sylvain Chaty, Nicolas Bessolaz

Aims: To gain a better understanding of high-energy Galactic sources, we observed the Galactic X-ray binary and black hole candidate XTE J1720-318 in the optical and near-infrared, just after the onset of its X-ray outburst in January, 2003. These observations were obtained with the ESO/NTT as the Target of Opportunity, in February and April 2003. Methods: W

C. R. Pontes, A. P. Baeta Scarpelli, Marcos Sampaio, M. C. Nemes

Implicit regularization (IR) has been shown as an useful momentum space tool for perturbative calculations in dimension specific theories, such as chiral gauge, topological and supersymmetric quantum field theoretical models at one loop level. In this paper, we aim at generalizing systematically IR to be applicable beyond one loop order. We use a scalar fiel

Emily Hackett-Jones, George Moutsopoulos

We investigate the quantum mechanics of the doubled torus system, introduced by Hull [1] to describe T-folds in a more geometric way. Classically, this system consists of a world-sheet Lagrangian together with some constraints, which reduce the number of degrees of freedom to the correct physical number. We consider this system from the point of view of cons

Wolfgang Schleifenbaum, Markus Leder, Hugo Reinhardt

The infrared behaviour of gluon and ghost propagators, ghost-gluon vertex and three-gluon vertex is investigated for both the covariant Landau and the non-covariant Coulomb gauge. Assuming infrared ghost dominance, we find a unique infrared exponent in the d=4 Landau gauge, while in the d=3+1 Coulomb gauge we find two different infrared exponents. We also sh

Michael Mayer, Ilya Molchanov

We prove a limit theorem for the the maximal interpoint distance (also called the diameter) for a sample of n i.i.d. points in the unit ball of dimension 2 or more. The exact form of the limit distribution and the required normalisation are derived using assumptions on the tail of the interpoint distance for two i.i.d. points. The results are specialised for

V. F. Mitrovic, M. Horvatic, C. Berthier, G. Knebel

We report $^{115}$In nuclear magnetic resonance (NMR) measurements of the heavy-fermion superconductor CeCoIn$_5$ in the vicinity of the superconducting critical field $H_{c2}$ for a magnetic field applied perpendicular to the $\hat c$-axis. A possible inhomogeneous superconducting state, Fulde-Ferrel-Larkin-Ovchinnikov (FFLO), is stabilized in this part of

Luis Alvarez-Gaume, Frank Meyer, Miguel A. Vazquez-Mozo

We study the possibility of obtaining noncommutative gravity dynamics from string theory in the Seiberg-Witten limit. We find that the resulting low-energy theory contains more interaction terms than those proposed in noncommutative deformations of gravity. The role of twisted diffeomorphisms in string theory is studied and it is found that they are not stan

B. I. Ermolaev, M. Greco, S. I. Troyan

Explicit expressions for the singlet g_1 at small x and small Q^2 are obtained with the total resummation of the leading logarithmic contributions. It is shown that g_1 practically does not depend on Q^2 in this kinematic region. In contrast, it would be interesting to investigate its dependence on the invariant energy 2pq because, being g_1 positive at smal

A. Maier, J. C. Niemeyer

In the context of explosion models for Type Ia Supernovae, we present one- and two-dimensional simulations of fully resolved detonation fronts in degenerate C+O White Dwarf matter including clumps of previously burned material. The ability of detonations to survive the passage through sheets of nuclear ashes is tested as a function of the width and compositi

Seonhee Lim, Anne Thomas

We develop an explicit covering theory for complexes of groups, parallel to that developed for graphs of groups by Bass. Given a covering of developable complexes of groups, we construct the induced monomorphism of fundamental groups and isometry of universal covers. We characterize faithful complexes of groups and prove a conjugacy theorem for groups acting

P. A. A. Lopes, R. R. de Carvalho, H. V. Capelato, R. R. Gal

We present a comparison of optical and X-ray properties of galaxy clusters in the northern sky. We determine the recovery rate of X-ray detected clusters in the optical as a function of richness, redshift and X-ray luminosity, showing that the missed clusters are typically low contrast systems when observed optically. We employ four different statistical tes

W. M. Stuckey, Michael Silberstein, Michael Cifone

The transition from the quantum realm to the classical realm is described in the context of the Relational Blockworld (RBW) interpretation of non-relativistic quantum mechanics. We first introduce RBW, discuss its philosophical implications and provide an example of its explanatory methodology via the so-called &#34;quantum liar experiment.&#34; We then prov

A. G. Oganesian

The pentaquark width is calculated in QCD sum rules. Result for $Γ_Θ$ show, that $Γ_Θ$ can vary in the region less than 1$MeV$. The main conclusion is, that if pentaquark is genuine states then sum rules really predict the narrow width of pentaquark $θ^+$, and the suppression of the width is both parametrical and numerical.

Vladimir V. Kornyak

The cellular automata with local permutation invariance are considered. We show that in the two-state case the set of such automata coincides with the generalized Game of Life family. We count the number of equivalence classes of the rules under consideration with respect to permutations of states. This reduced number of rules can be efficiently generated in

J. Fine, J. Ross

We show that positivity of the CM line associated to a family of polarised varieties is intimately related to the stability of its members. We prove that the CM line is nef on any curve which meets the stable locus, and that it is pseudoeffective (i.e. in the closure of the effective cone) as long as there is at least one stable fibre. We give examples showi

E. D. L. Wickham, A. Stroeer, A. Vecchio

The Laser Interferometer Space Antenna (LISA) will produce a data stream containing a vast number of overlapping sources: from strong signals generated by the coalescence of massive black hole binary systems to much weaker radiation form sub-stellar mass compact binaries and extreme-mass ratio inspirals. It has been argued that the observation of weak signal

Metod Saniga, Michel Planat, Maurice Kibler, Petr Pracna

A compact classification of the projective lines defined over (commutative) rings (with unity) of all orders up to thirty-one is given. There are altogether sixty-five different types of them. For each type we introduce the total number of points on the line, the number of points represented by coordinates with at least one entry being a unit, the cardinalit

F. Polci, M. -H. Schune, A. Stocchi

In this paper we present a feasibility study for measuring the combination of the Unitarity Triangle angle 2$β+γ$ with a time dependent Dalitz analysis in $B^0$ decays using $D^- K^0 π^+$ final states following the method proposed in [1]. For this study we build a model for this decay using the latest experimental information and we investigate the possibili

T. Z. Yan, Y. G. Ma, X. Z. Cai, J. G. Chen

Anisotropic flows ($v_2$ and $v_4$) of light nuclear clusters are studied by Isospin-Dependent Quantum Molecular Dynamics model for the system of $^{86}$Kr + $^{124}$Sn at intermediate energy and large impact parameters. Number-of-nucleon scaling of the elliptic flow ($v_2$) are demonstrated for the light fragments up to $A$ = 4, and the ratio of $v_4/v_2^2$

Masataka Ando, Kouji Ohta, Ikuru Iwata, Masayuki Akiyama

We report a deficiency of luminous Lyman break galaxies (LBGs) with a large rest-frame equivalent width (EW_rest) of Lyman-alpha emission at z~5-6. Combining our spectroscopic sample of LBGs at z~5 and those from the literature, we found that luminous LBGs at z~5-6 generally show weak Lyman-alpha emissions, while faint LBGs show a wide range of Lyman-alpha E

Eiji Mitsuda, Akira Tomimatsu

Stability of self-similar solutions for gravitational collapse is an important problem to be investigated from the perspectives of their nature as an attractor, critical phenomena and instability of a naked singularity. In this paper we study spherically symmetric non-self-similar perturbations of matter and metrics in spherically symmetric self-similar back

M. Ablikim, BES Collaboration

Using 14 million $ψ(2S)$ events collected with the Beijing Spectrometer (BESII) at the Beijing Electron-Positron Collider, the branching fractions of $ψ(2S)$ decays to $p \bar{n} π^-$ and $\bar{p} n π^+$ and the branching fractions of the main background channels $ψ(2S) \to p \bar{n} π^-π^0$, $ψ(2S) \to γχ_{c0} \to γp \bar{n} π^-$, $ψ(2S) \to γχ_{c2} \to γp

Volodymyr Krasnoholovets, Jean-Louis Tane

Although its practical efficiency is unquestionable, the thermodynamic tool presents a slight inconsistency from the theoretical point of view. After exposing arguments, which explain this opinion, a suggestion is put forward to solve the problem. It consists of linking the mass-energy relation d m = m c^{2} to the laws of thermodynamics. This combination re

Kevork Abazajian, Savvas M. Koushiappas

We present a comprehensive analysis of constraints on the sterile neutrino as a dark matter candidate. The minimal production scenario with a standard thermal history and negligible cosmological lepton number is in conflict with conservative radiative decay constraints from the cosmic X-ray background in combination with stringent small-scale structure limit

M. M. Sheikh-Jabbari

In this letter we show that the noncommutative spaces, and in particular fuzzy spheres, are natural candidates which explicitly exhibit the holography, by noting that the smallest physically accessible volume is much larger that the expected Planckian size. Moreover, we show that fuzzy spheres provide us with a new approach, &#39;&#39;an $N$-tropic&#39;&#39;

Zhi-Yong Wang, Cai-Dong Xiong, Ole Keller

In near-field optics and optical tunneling theory, photon wave mechanics, i.e., the first quantized theory of the photon, allows us to address the spatial field localization problem in a flexible manner which links smoothly to classical electromagnetics. In this letter, photon wave mechanics is developed in a rigorous and unified way, based on which field qu

Zhi-Yong Wang, Cai-Dong Xiong

Traditionally, the theory related to the spatial angular momentum has been studied completely, while the investigation in the generator of Lorentz boost is inadequate. In this paper we show that the generator of Lorentz boost has a nontrivial physical significance, it endows a charged system with an electric moment, and has an important significance for the

S. Rebic, C. Ottaviani, G. Di Giuseppe, D. Vitali

We analyze in detail the proposal for a two-qubit gate for travelling single-photon qubits recently presented by C. Ottaviani \emph{et al}. [Phys. Rev. A \textbf{73}, 010301(R) (2006)]. The scheme is based on an ensemble of five-level atoms coupled to two quantum and two classical light fields. The two quantum fields undergo cross-phase modulation induced by

G. Letawe, P. Magain, F. Courbin, P. Jablonka

We present the analysis of a sample of 20 bright low-redshift quasars (M_B<-23 and z < 0.35) observed spectroscopically with the VLT. The FORS1 spectra, obtained in Multi Object Spectroscopy (MOS) mode, allow to observe simultaneously the quasars and several reference stars used to spatially deconvolve the data. Applying the MCS deconvolution method, we are

Yves Brihaye, Eugen Radu

We present arguments for the existence of self-dual Yang-Mills instantons for several spherically symmetric backgrounds with Euclidean signature. The time-independent Yang-Mills field has finite action and a vanishing energy momentum tensor and does not disturb the geometry. We conjecture the existence of similar solutions for any nonextremal SO(3)-spherical

Helene Perrin, Yves Colombe, Brigitte Mercier, Vincent Lorent

We present experimental results showing the diffuse reflection of a Bose-Einstein condensate from a rough mirror, consisting of a dielectric substrate supporting a blue-detuned evanescent wave. The scattering is anisotropic, more pronounced in the direction of the surface propagation of the evanescent wave. These results agree very well with theoretical pred

Kourosh Nozari, Behnaz Fazlpour

We investigate the effects of space noncommutativity and the generalized uncertainty principle on the thermodynamics of a radiating Schwarzschild black hole. We show that evaporation process is in such a way that black hole reaches to a maximum temperature before its final stage of evolution and then cools down to a nonsingular remnant with zero temperature