January 2006 arXiv papers — page 36
Showing 3,501–3,600 of 3,943 papers
G. G. Kirilin
Quantum corrections to the Schwarzschild metric generated by loop diagrams have been considered by Bjerrum-Bohr, Donoghue, and Holstein (BHD) [Phys. Rev. D68, 084005 (2003)], and Khriplovich and Kirilin (KK) [J. Exp. Theor. Phys. 98, 1063 (2004)]. Though the same field variables in a covariant gauge are used, the results obtained differ from one another. The
Adiabatic Expansion for Metric Perturbation and the condition to solve the Gauge Problem for Gravitational Radiation Reaction Problem
gr-qcYasushi Mino
We examine the adiabatic approximation in the study of a relativistic two-body problem with the gravitational radiation reaction. We recently pointed out that the usual metric perturbation scheme using a perturbation of the stress-energy tensor may not be appropriate for study of the dissipative dynamics of the bodies due to the radiation reaction. We recent
N-spheres in general relativity: regular black holes without apparent horizons, static wormholes with event horizons and gravastars with a tube-like core
gr-qcO. B. Zaslavskii
We consider a way to avoid black hole singularities by gluing a black hole exterior to an interior with a tube-like geometry consisting of a direct product of two-dimensional AdS, dS, or Rindler spacetime with a two-sphere of constant radius. As a result we obtain a spacetime with either "cosmological" or "acceleration" (event) horizons but w
Xiaowen Zhang, Li Shu, Ke Tang
In this paper we propose a multi-map orbit hopping chaotic stream cipher that utilizes the idea of spread spectrum mechanism for secure digital communications and fundamental chaos characteristics of mixing, unpredictable, and extremely sensitive to initial conditions. The design, key and subkeys, and detail implementation of the system are addressed. A vari
Ben Moszkowski
We present a hierarchical framework for analysing propositional linear-time temporal logic (PTL) to obtain standard results such as a small model property, decision procedures and axiomatic completeness. Both finite time and infinite time are considered and one consequent benefit of the framework is the ability to systematically reduce infinite-time reasonin
Bertrand Nouvel, Eric Remila
A discrete rotation algorithm can be apprehended as a parametric application $f\_α$ from $\ZZ[i]$ to $\ZZ[i]$, whose resulting permutation ``looks like'' the map induced by an Euclidean rotation. For this kind of algorithm, to be incremental means to compute successively all the intermediate rotate d copies of an image for angles in-between 0 and a d
R. D. Luttrell, S. Brown, J. Cao, J. L. Musfeldt
We measured the infrared vibrational properties of bulk and nanoparticle WS$_2$ in order to investigate the structure-property relations in these novel materials. In addition to the symmetry-breaking effects of local strain, nanoparticle curvature modifies the local charging environment of the bulk material. Performing a charge analysis on the \emph{xy}-pola
Andrew J. Heim, Niels Grønbech-Jensen, Timothy C. Germann, Edward M. Kober
The dependence of macroscopic detonation properties of a two-dimensional diatomic (AB) molecular system on the fundamental properties of the molecule were investigated. This includes examining the detonation velocity, reaction zone thickness, and critical width as a function of the exothermicity of the gas-phase reaction and the gas-phase dissociation energy
Alexander Punnoose, Alexander M. Finkel'stein
The D'yakonov-Perel' spin relaxation induced by the spin-orbit interaction is examined in disordered two-dimensional electron gas. It is shown that, because of the electron-electron interactions different spin relaxation rates can be obtained depending on the techniques used to extract them. It is demonstrated that the relaxation rate of a spin popul
J. -X. Lin, C. Reichhardt, Z. Nussinov, Leonid P. Pryadko
We simulate a model of repulsively interacting colloids on a commensurate two-dimensional triangular pinning substrate where the amount of heterogeneous motion that appears at melting can be controlled systematically by turning off a fraction of the pinning sites. We correlate the amount of heterogeneous motion with the average topological defect number, tim
Micromagnetic simulations of the magnetization precession induced by a spin polarized current in a point contact geometry
cond-mat.mes-hallD. V. Berkov, N. L. Gorn
This paper is devoted to numerical simulations of the magnetization dynamics driven by a spin-polarized current in extended ferromagnetic multilayers when a point-contact setup is used. We present (i) detailed analysis of methodological problems arising by such simulations and (ii) physical results obtained on a system similar to that studied in Rippard et a
Investigation of the charge transport through disordered organic molecular heterojunctions
cond-mat.otherH. Houili, E. Tutis, I. Batistic, L. Zuppiroli
We develop a new three-dimensional multiparticle Monte Carlo ({\it 3DmpMC}) approach in order to study the hopping charge transport in disordered organic molecular media. The approach is applied here to study the charge transport across an energetically disordered organic molecular heterojunction, known to strongly influence the characteristics of the multil
Claire Levelut, Rozenn Le Parc, Jacques Pelous
In order to clarify the origin of the dominant processes responsible for the acoustic attenuation of phonons, which is a much debatted topic, we present Bril louin scattering experiments in various silica glasses of different OH impurities content. A large temperature range, from 5 to 1500 K is investigated, up to the glass transition temperature. Comparison
Correlating supercooling limit and glass-like arrest of kinetics for disorder-broadened 1st order transitions: relevance to phase separation
cond-mat.str-elP. Chaddah, A. Banerjee, S. B. Roy
Coexisting ferromagnetic (FM) and antiferromagnetic (AFM) phases over a range of temperature (T) and magnetic field (H), have been reported in many materials. The 1st order FM-AFM transition is completed over a broad T (or H) range; this is ascribed to a landscape of free-energy density in systems with frozen disorder. Kinetic arrest, akin to glass transitio
Two-dimensional structure in a generic model of triangular proteins and protein trimers
cond-mat.softPhilip J. Camp, Peter D. Duncan
Motivated by the diversity and complexity of two-dimensional crystals formed by triangular proteins and protein trimers, we have investigated the structures and phase behavior of hard-disk trimers. In order to mimic specific binding interactions, each trimer possesses on `attractive' disk which can interact with similar disks on other trimers via an attr
Rudolf Podgornik, Ali Naji
We investigate the effect of quenched surface charge disorder on electrostatic interactions between two charged surfaces in the presence of dielectric inhomogeneities and added salt. We show that in the linear weak-coupling regime (i.e., by including mean-field and Gaussian-fluctuations contributions), the image-charge effects lead to a non-zero disorder-ind
Electrical Detection of Self-Assembled Polyelectrolyte Multilayers by a Thin Film Resistor
cond-mat.softPetra A. Neff, Ali Naji, Christof Ecker, Bert Nickel
The build up of polyelectrolyte multilayers (PEMs) was observed by a silicon-on-insulator (SOI) based thin film resistor. Differently charged polyelectrolytes adsorbing to the sensor surface result in defined potential shifts, which decrease with the number of layers deposited. We model the response of the device assuming electrostatic screening of polyelect
Is the entropy at the liquid-gas critical point of pure fluids proportional to a master dimensionless constant ?
cond-mat.stat-mechYves Garrabos
From a minimal set made of four scale factors defined at the liquid-gas critical point of a pure fluid, and one adjustable parameter which accounts for particle quantum effects, we demonstrate here a master singular behavior of the correlation length for the one-component fluid subclass, using an asymptotic scale dilatation of the physical fields. Such maste
Laurent Ponson, Daniel Bonamy, Elisabeth Bouchaud
The morphology of fracture surfaces encodes the various complex damage and fracture processes occurring at the microstructure scale that have lead to the failure of a given heterogeneous material. Understanding how to decipher this morphology is therefore of fundamental interest. This has been extensively investigated over these two last decades. It has been
Laurent Ponson, Daniel Bonamy, Harold Auradou, Guillaume Mourot
The scaling properties of post-mortem fracture surfaces of brittle (silica glass), ductile (aluminum alloy) and quasi-brittle (mortar and wood) materials have been investigated. These surfaces, studied far from the initiation, were shown to be self-affine. However, the Hurst exponent measured along the crack direction is found to be different from the one me
Oleg L. Berman, Yurii E. Lozovik, Sergey L. Eiderman, Rob D. Coalson
The band structure of a novel type of photonic crystal with superconducting constituent elements is calculated numerically via a plane wave expansion. The density of states and the dependence of the width of the photonic gap on the filling factor is analyzed for a two-dimensional photonic crystal consisting of an infinite array of parallel superconducting cy
C. H. Booth, M. D. Walter, M. Daniel, W. W. Lukens
Kondo coupling of f and conduction electrons is a common feature of f-electron intermetallics. Similar effects should occur in carbon ring systems(metallocenes). Evidence for Kondo coupling in Ce(C8H8)2 (cerocene) and the ytterbocene Cp*2Yb(bipy) is reported from magnetic susceptibility and L_III-edge x-ray absorption spectroscopy. These well-defined systems
H. Guclu, G. Korniss, M. A. Novotny, Z. Toroczkai
Motivated by a synchronization problem in distributed computing we studied a simple growth model on regular and small-world networks, embedded in one and two-dimensions. We find that the synchronization landscape (corresponding to the progress of the individual processors) exhibits Kardar-Parisi-Zhang-like kinetic roughening on regular networks with short-ra
Thomas Ramstad, Alex Hansen
We report numerical studies of the cluster development of two-phase flow in a steady-state environment of porous media. This is done by including biperiodic boundary conditions in a two-dimensional flow simulator. Initial transients of wetting and non-wetting phases that evolve before steady-state has occurred, undergo a cross-over where every initial patter
K. -W. Lee, W. E. Pickett
Comparison of periodic B dopants with a random alloy of substitional boron in diamond is carried out using several supercells and the coherent potential approximation (CPA) for the random alloy case. The main peak in the B local density of states is shifted to lower binding energy compared to the corresponding C peak in intrinsic diamond. In supercells, this
Microstructure and velocity of field-driven solid-on-solid interfaces moving under stochastic dynamics with local energy barriers
cond-mat.mtrl-sciG. M. Buendia, P. A. Rikvold, M. Kolesik
We study the microscopic structure and the stationary propagation velocity of (1+1)-dimensional solid-on-solid interfaces in an Ising lattice-gas model, which are driven far from equilibrium by an applied force, such as a magnetic field or a difference in (electro)chemical potential. We use an analytic nonlinear-response approximation [P.A. Rikvold and M. Ko
C. Yang, U. Tartaglino, B. N. J. Persson
The friction and adhesion between elastic bodies are strongly influenced by the roughness of the surfaces in contact. Here we develop a multiscale molecular dynamics approach to contact mechanics, which can be used also when the surfaces have roughness on many different length-scales, e.g., for self affine fractal surfaces. As an illustration we consider the
M. Houzet, V. Vinokur, F. Pistolesi
Critical current was recently measured near the transition from 0 to $π$-contact in superconductor/ferromagnet/superconductor Josephson junctions. Contrary to expectations, it does not vanish at the transition point. It shows instead a tiny, though finite, minimum. The observation of fractional Shapiro steps reenforces the idea that the vanishing of the main
Roberta M. Humphreys, Terry J. Jones, Elisha Polomski, Michael Koppelman
Variable A in M33 is a member of a rare class of highly luminous, evolved stars near the upper luminosity boundary that show sudden and dramatic shifts in apparent temperature due to the formation of optically thick winds in high mass loss episodes. Recent optical and infrared spectroscopy and imaging reveal that its ``eruption'' begun in $\sim$1950
C. M. Oliveira, H. Warren Moos, Pierre Chayer, Jeffrey W. Kruk
We use data obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE) to determine the interstellar abundances of DI, NI, OI, FeII, and H2 along the sigh tlines to WD1034+001, BD+393226, and TD132709. Our main focus is on determining the D/H, N/H, O/H, and D/O ratios along these sightlines, with log N(H) > 20.0, that probe gas well outside of the Local
Karl Glazebrook, Aprajita Verma, Brian Boyle, Sebastian Oliver
We present a deep photometric (B- and R-band) catalog and an associated spectroscopic redshift survey conducted in the vicinity of the Hubble Deep Field South. The spectroscopy yields 53 extragalactic redshifts in the range 0<z<1.4 substantially increasing the body of spectroscopic work in this field to over 200 objects. The targets are selected from deep AA
Pavel Denissenkov, Brian Chaboyer, Ke Li
Stellar models which incorporate simple diffusion or shear induced mixing are used to describe canonical extra mixing in low mass red giants of low and solar metallicity. These models are able to simultaneously explain the observed Li and CN abundance changes along upper red giant branch (RGB) in field low-metallicity stars and match photometry, rotation and
Are non-magnetic mechanisms such as temporal solar diameter variations conceivable for an irradiance variability?
astro-phJ. P. Rozelot, S. Lefebvre, S. Pireaux, A. Ajabshirizadeh
Irradiance variability has been monitored from space for more than two decades. Even if data are coming from different sources, it is well established that a temporal variability exists which can be set to as approximately 0.1%, in phase with the solar cycle. Today, one of the best explanation for such an irradiance variability is provided by the evolution o
A. Boselli, G. Gavazzi
The transformations taking place in late-type galaxies in the environment of rich clusters of galaxies at z=0 are reviewed. From the handful of late-type galaxies that inhabit local clusters, whether they were formed in-situ and survived as such, avoiding transformation or even destruction or if they are newcomers that recently infall from outside, we can le
G. Efstathiou
This paper generalises the hybrid power spectrum estimator developed in Efstathiou (2004a) to the estimation of polarization power spectra of the cosmic microwave background radiation. The hybrid power spectrum estimator is unbiased and we show that it is close to optimal at all multipoles, provided the pixel noise satisfies certain reasonable constraints. F
A Chandra/ACIS Study of 30 Doradus II. X-ray Point Sources in the Massive Star Cluster R136 and Beyond
astro-phL. K. Townsley, P. S. Broos, E. D. Feigelson, G. P. Garmire
We have studied the X-ray point source population of the 30 Doradus star-forming complex in the Large Magellanic Cloud using high-spatial-resolution X-ray images and spatially-resolved spectra obtained with the Advanced CCD Imaging Spectrometer (ACIS) aboard the Chandra X-ray Observatory. Here we describe the X-ray sources in a 17' x 17' field center
L. K. Townsley, P. S. Broos, E. D. Feigelson, B. R. Brandl
We present an X-ray tour of diffuse emission in the 30 Doradus star-forming complex in the Large Magellanic Cloud using high-spatial-resolution X-ray images and spatially-resolved spectra obtained with the Advanced CCD Imaging Spectrometer aboard the Chandra X-ray Observatory. The dominant X-ray feature of the 30 Doradus nebula is the intricate network of di
Gavin Ramsay, Mark Cropper, Pasi Hakala
The nature of the X-ray source RX J1914+24 has been the subject of much debate. It shows a prominent period of 569 sec in X-rays and the optical/infra-red: in most models this has been interpreted as the binary orbital period. We present our analysis of new XMM-Newton and Chandra data. We find a longer term trend in the XMM-Newton data and power at 556 and 5
Christian R. Kaiser
Flat radio spectra with large brightness temperatures at the core of AGN and X-ray binaries are usually interpreted as the partially self-absorbed bases of jet flows emitting synchrotron radiation. Here we extend previous models of jets propagating at large angles to our line of sight to self-consistently include the effects of energy losses of the relativis
Philip Massey
We present spectroscopy and discuss the photometric history of a previously obscure star in M31. The spectrum of the star is an extremely close match to that of P Cygni, one of the archetypes of Luminous Blue Variables (LBVs). The star has not shown much variability over the past 40 years ($<0.2$ mag), although small-scale (0.05 mag) variations over a year a
Optical Spectroscopy of X-Mega targets in the Carina Nebula - VI. FO 15: a new O-Type double-lined eclipsing binary
astro-phV. S. Niemela, N. I. Morrell, E. Fernandez Lajus, R. Barba
We report the discovery of a new O-type double-lined spectroscopic binary with a short orbital period of 1.4 days. We find the primary component of this binary, FO 15, to have an approximate spectral type O5.5Vz, i.e. a Zero-Age-Main-Sequence star. The secondary appears to be of spectral type O9.5V. We have performed a numerical model fit to the public ASAS
Fabrice Herpin, Alain Baudry, Clemens Thum, Dave Morris
We study the polarization of the SiO maser emission in a representative sample of evolved stars in order to derive an estimate of the strength of the magnetic field, and thus determine the influence of this magnetic field on evolved stars. We made simultaneous spectroscopic measurements of the 4 Stokes parameters, from which we derived the circular and linea
Philippe Salomé, Francoise Combes
Cold molecular gas has recently been found is several cooling flow clusters cores with single dish telescopes. High spatial resolution imaging of some of these clusters then revealed the peculiar morphology and dynamics of the CO emission lines, pointing out a perturbed very cold component in the cluster centers. We report here the observations of NGC 1275,
Edward C. D. Pope, Georgi Pavlovski, Christian R. Kaiser, Hans Fangohr
In recent years evidence has accumulated suggesting that the gas in galaxy clusters is heated by non-gravitational processes. Here we calculate the heating rates required to maintain a physically motived mass flow rate, in a sample of seven galaxy clusters. We employ the spectroscopic mass deposition rates as an observational input along with temperature and
Keiichi Wada, Eiichiro Kokubo, Junichiro Makino
In order to examine the ``giant impact hypothesis'' for the Moon formation, we run the first grid-based, high-resolution hydrodynamic simulations for an impact between proto-Earth and a proto-planet. The spatial resolution for the impact-generated disk is greatly improved from previous particle-based simulations. This allows us to explore fine struct
Jacco Vink
This paper discusses several aspects of current research on high energy emission from supernova remnants, covering the following main topics: 1) The recent evidence for magnetic field amplification near supernova remnant shocks, which makes that cosmic rays are more efficiently accelerated than previously thought. 2) The evidence that ions and electrons in s
K. Chiu, X. Fan, S. K. Leggett, D. A. Golimowski
We present near-infrared observations of 71 newly discovered L and T dwarfs, selected from imaging data of the Sloan Digital Sky Survey (SDSS) using the i-dropout technique. Sixty-five of these dwarfs have been classified spectroscopically according to the near-infrared L dwarf classification scheme of Geballe et al. and the unified T dwarf classification sc
J. C. Lair, M. D. Leising, P. A. Milne, G. G. Williams
The use of Type Ia supernovae as cosmological tools has reinforced the need to better understand these objects and their light curves. The light curves of Type Ia supernovae are powered by the nuclear decay of $^{56}Ni \to ^{56}Co \to ^{56}Fe$. The late time light curves can provide insight into the behavior of the decay products and their effect of the shap
Peter K. G. Williams, David Charbonneau, Curtis S. Cooper, Adam P. Showman
We present a method that employs the secondary eclipse light curves of transiting extrasolar planets to probe the spatial variation of their thermal emission. This technique permits an observer to resolve the surface of the planet without the need to spatially resolve its central star. We evaluate the feasibility of this technique for the HD 209458 system [.
Benoit Fresse
The standard reduced bar complex B(A) of a differential graded algebra A inherits a natural commutative algebra structure if A is a commutative algebra. We address an extension of this construction in the context of E-infinity algebras. We prove that the bar complex of any E-infinity algebra can be equipped with the structure of an E-infinity algebra so that
Mathieu Dutour Sikiric, Achill Schuermann, Frank Vallentin
We consider Voronoi's reduction theory of positive definite quadratic forms which is based on Delone subdivision. We extend it to forms and Delone subdivisions having a prescribed symmetry group. Even more general, the theory is developed for forms which are restricted to a linear subspace in the space of quadratic forms. We apply the new theory to compl
Jakob Kellner, Saharon Shelah
For $f,g\inω\ho$ let $\mycfa_{f,g}$ be the minimal number of uniform $g$-splitting trees needed to cover the uniform $f$-splitting tree, i.e. for every branch $ν$ of the $f$-tree, one of the $g$-trees contains $ν$. $\myc_{f,g}$ is the dual notion: For every branch $ν$, one of the $g$-trees guesses $ν(m)$ infinitely often. It is consistent that $\myc_{f_ε,g_ε
Jacob Scheuer, Amnon Yariv
We present a comprehensive analysis of the Johnson (like) noise based classical key-distribution scheme presented by Kish [1]. We suggest two passive attack strategies that enable an adversary to gain complete knowledge of the exchanged key. The first approach exploits the transient response of the voltage difference on the transmission line after the resist
Pran Nath, Pavel Fileviez Perez
A broad overview of the current status of proton stability in unified models of particle interactions is given which includes non - supersymmetric unification, SUSY and SUGRA unified models, unification based on extra dimensions, and string-M-theory models. The extra dimensional unification includes 5D and 6D and universal extra dimensional (UED) models, and
The mobility of dual vortices in honeycomb, square, triangular, Kagome and dice lattices
cond-mat.str-elLonghua Jiang, Jinwu Ye
It was known that by a duality transformation, interaction bosons at filling factor $ f=p/q $ hopping on a lattice can be mapped to interacting vortices hopping on the dual lattice subject to a fluctuating{\em dual} " magnetic field" whose average strength through a dual plaquette is equal to the boson density $ f=p/q $.So the kinetic term of the vor
Murray W. McCutcheon, Jeff F. Young, Georg W. Rieger, Dan Dalacu
Polarization-resolved second-harmonic spectra are obtained from the resonant modes of a two-dimensional planar photonic crystal microcavity patterned in a free-standing InP slab. The photonic crystal microcavity is comprised of a single missing-hole defect in a hexagonal photonic crystal host formed with elliptically-shaped holes. The cavity supports two ort
Frederic Faure, Nicolas Roy
We study two simple real analytic uniformly hyperbolic dynamical systems: expanding maps on the circle S1 and hyperbolic maps on the torus T2. We show that the Ruelle-Pollicott resonances which describe time correlation functions of the chaotic dynamics can be obtained as the eigenvalues of a trace class operator in Hilbert space L2(S1) or L2(T2) respectivel
Anisse Kasraoui, Jiang Zeng
We construct an involution on set partitions which keeps track of the numbers of crossings, nestings and alignments of two edges. We derive then the symmetric distribution of the numbers of crossings and nestings in partitions, which generalizes Klazar's recent result in perfect matchings. By factorizing our involution through bijections between set partitio
Janet P. Simpson, Sean W. J. Colgan, Edwin F. Erickson, Michael G. Burton
We present 2micron polarization measurements of positions in the BN region of the Orion Molecular Cloud (OMC-1) made with NICMOS Camera 2 (0.2'' resolution) on HST. Our results are as follows: BN is sim 29% polarized by dichroic absorption and appears to be the illuminating source for most of the nebulosity to its north and up to sim 5'' to i
A. Faggionato
Given a doubly infinite sequence of positive numbers {c_k: k in Z} satisfying a LLN with limit A, we consider the nearest-neighbor simple exclusion process on Z where c_k is the probability rate of jumps between k and k+1. If A is infinite we require an additional minor technical condition. By extending a method developed by K. Nagy, we show that the diffusi
C. Nepali, G. Fai, D. Keane
Collisions of deformed uranium nuclei are studied in a Monte-Carlo Glauber model. For U+U at zero impact parameter (b=0) in the most favorable orientation (tip-to-tip), the transverse particle density (charged-particle rapidity density per weighted transverse area of the initial participant zone) increases by about 35% compared to Au+Au at b=0. To estimate t
Thomas G. Rizzo
We examine the mass loss rates and lifetimes of TeV-scale extra dimensional black holes (BH) in ADD-like models with Lovelock higher-curvature terms present in the action. In particular we focus on the predicted differences between the canonical and microcanonical ensemble statistical mechanics descriptions of the Hawking radiation that results in the decay
S. E. Bisschop, H. J. Fraser, K. I. Oberg, E. F. van Dishoeck
We present Temperature Programmed Desorption (TPD) experiments of CO and N2 ices in pure, layered and mixed morphologies at various ice "thicknesses" and abundance ratios as well as simultaneously taken Reflection Absorption Infrared Spectra (RAIRS) of CO. A kinetic model has been developed to constrain the binding energies of CO and N2 in both pure
Lattice relaxation, electronic screening, and spin and orbital phase diagram of LaTiO$_3$/SrTiO$_3$ superlattices
cond-mat.str-elSatoshi Okamoto, Andrew J. Millis, Nicola A. Spaldin
The effects of lattice relaxation in LaTiO$_3$/SrTiO$_3$ superlattices are investigated using a combination of LDA$+U$ density functional theory, and Hartree-Fock effective Hamiltonian calculations. We find noticeable ($\sim 0.1$--0.2 \AA) distortions of the TiO$_6$ octahedra in the near-La region. The resulting screening changes the Ti $d$-electron density
Eric Moulines, François Roueff, Murad S. Taqqu
We consider a time series $X=\{X_k, k\in\mathbb{Z}\}$ with memory parameter $d\in\mathbb{R}$. This time series is either stationary or can be made stationary after differencing a finite number of times. We study the "Local Whittle Wavelet Estimator" of the memory parameter $d$. This is a wavelet-based semiparametric pseudo-likelihood maximum method e
Maciej Dunajski
A class of time dependent solutions to $(3+1)$ Einstein--Maxwell-dilaton theory with attractive electric force is found from Einstein--Weyl structures in (2+1) dimensions corresponding to dispersionless Kadomtsev--Petviashvili and $SU(\infty)$ Toda equations. These solutions are obtained from time--like Kaluza--Klein reductions of $(3+2)$ solitons.
Max Little, Patrick E. McSharry, Irene M. Moroz, Stephen J. Roberts
This paper develops an improved surrogate data test to show experimental evidence, for all the simple vowels of US English, for both male and female speakers, that Gaussian linear prediction analysis, a ubiquitous technique in current speech technologies, cannot be used to extract all the dynamical structure of real speech time series. The test provides robu
D. Frettlöh, B. Sing
Computing modular coincidences can show whether a given substitution system, which is supported on a point lattice in R^d, consists of model sets or not. We prove the computatibility of this problem and determine an upper bound for the number of iterations needed. The main tool is a simple algorithm for computing modular coincidences, which is essentially a
Fermions in Ashtekar-Barbero Connections Formalism for Arbitrary Values of the Immirzi Parameter
gr-qcSimone Mercuri
The Ashtekar-Barbero-Immirzi formulation of General Relativity is extended to include spinor matter fields. Our formulation applies to generic values of the Immirzi parameter and reduces to the Ashtekar-Romano-Tate approach when the Immirzi parameter is taken equal to the imaginary unit. The dynamics of the gravity-fermions coupled system is described by the
Study on successive superconducting transitions in Ta$_{2}$S$_{2}$C from electrical resistivity and nonlinear AC magnetic susceptibility
cond-mat.supr-conMasatsugu Suzuki, Itsuko S. Suzuki, Takashi Noji, Yoji Koike
Ta$_{2}$S$_{2}$C compound undergoes superconducting transitions at $T_{cl} = 3.60 \pm 0.02$ K and $T_{cu} = 9.0 \pm 0.2$ K. The nature of successive superconducting transitions has been studied from electrical resistivity, linear and nonlinear AC magnetic susceptibilities. The resistivity $ρ$ at $H$ = 0 shows a local maximum near $T_{cu}$, a kink-like behavi
J. Mareš, E. Friedman, A. Gal
A comprehensive data base of K- atom level shifts and widths is re-analyzed in order to study the density dependence of the Kbar-nuclear optical potential. Significant departure from a t*rho form is found only for nuclear densities about and less than 20% of nuclear-matter density, and extrapolation to nuclear-matter density yields an attractive potential, a
Francesco Polizzi
A smooth algebraic surface $S$ is said to be \emph{isogenous to a product of unmixed type} if there exist two smooth curves $C, F$ and a finite group $G$, acting faithfully on both $C$ and $F$ and freely on their product, so that $S=(C \times F)/G$. In this paper we classify the surfaces of general type with $p_g=q=1$ which are isogenous to an unmixed produc
Yizhong Fan, Tsvi Piran
The discovery by Swift that a good fraction of Gamma Ray Bursts (GRBs) have a slowly decaying X-ray afterglow phase led to the suggestion that energy injection into the blast wave takes place several hundred seconds after the burst. This implies that right after the burst the kinetic energy of the blast wave was very low and in turn the efficiency of product
A. E. Mironov, I. A. Taimanov
We study the limiting case of the Krichever construction of orthogonal curvilinear coordinate systems when the spectral curve becomes singular. We show that the case when the curve is reducible and all its irreducible components are rational curves the construction procedure reduces to solving systems of linear equations and simple computations with elementa
Mark Kambites
We present an exposition of the theory of finite automata augmented with a multiply-only register storing an element of a given monoid or group. Included are a number of new results of a foundational nature. We illustrate our techniques with a group-theoretic interpretation and proof of a key theorem of Chomsky and Schutzenberger from formal language theory.
A. Andrievskii, S. Gurbatov, A. Sobolevskii
We consider exact solutions to the problem of ballistic aggregation in a flow of adhesive particles, providing a model for large-scale structure formation in cosmology within the framework of the Zel'dovich approximation. Two different explicit variational constructions, suggested for this problem by (A. Shnirelman, 1986) and (E Weinan et al, 1996) in th
G. V. Vereshchagin, G. Yegorian
The formula for dark energy density derived by Gurzadyan and Xue provides a value of density parameter of dark energy in remarkable agreement with current cosmological datasets, unlike numerous phenomenological dark energy scenarios where the corresponding value is postulated. This formula suggests the possibility of variation of physical constants such as t
Dariusz Chruscinski, Andrzej Kossakowski
We propose a natural generalization of bipartite Werner and isotropic states to multipartite systems consisting of an arbitrary even number of d-dimensional subsystems (qudits). These generalized states are invariant under the action of local unitary operations. We study basic properties of multipartite invariant states: separability criteria and multi-PPT c
Pressure-Induced Zero-Gap Semiconducting State in Organic Conductor $α$-(BEDT-TTF)$_2$I$_3$ Salt
cond-mat.mtrl-sciShinya Katayama, Akito Kobayashi, Yoshikazu Suzumura
We show a zero-gap semiconducting (ZGS) state in the quasi-two-dimensional organic conductor $α$-(BEDT-TTF)$_2$I$_3$ salt, which emerges under uniaxial pressure along the a-axis (the stacking axis of the BEDT-TTF molecule). The ZGS state is the state in which a Dirac cone with the band spectrum of a linear dispersion exists around the Fermi point connecting
Zhi-Gang Wang, Shao-Long Wan, Wei-Min Yang
In this article, we calculate the scalar form-factor of the proton in the framework of the light-cone QCD sum rules approach with the three valence quark light-cone distribution amplitudes up to twist-6, and observe the scalar form-factor $σ(t=-Q^2)$ at intermediate and large momentum transfers $Q^2> 2GeV^2$ has significant contributions from the end-point (
T. Hyodo, Sourav Sarkar, A. Hosaka, E. Oset
We study the coupling of the Lambda(1520)= Lambda* resonance to the \bar K* vector meson and nucleon. This coupling is not directly measured from the resonance decay, but is expected to be important in hyperon production reactions, in particular for the exotic Theta+ production. We compute the coupling in two different schemes, one in the chiral unitary mode
Daichi Kimura, Yoshinori Hayakawa
We study a reinforcement learning for temporal coding with neural network consisting of stochastic spiking neurons. In neural networks, information can be coded by characteristics of the timing of each neuronal firing, including the order of firing or the relative phase differences of firing. We derive the learning rule for this network and show that the net
Dongho Chae
We prove that there exists no self-similar finite time blowing up solution to the 3D incompressible Euler equations. By similar method we also show nonexistence of self-similar blowing up solutions to the divergence-free transport equation in $\Bbb R^n$. This result has direct applications to the density dependent Euler equations, the Boussinesq system, and
Friedrich Wehrung
We construct a distributive algebraic lattice D that is not isomorphic to the congruence lattice of any lattice. This solves a long-standing open problem, traditionally attributed to R. P. Dilworth, from the forties. The lattice D has compact top element and aleph omega+1 compact elements. Our results extend to all algebras possessing a polynomially definabl
Friedrich Wehrung
We prove that for any distributive join-semilattice S, there are a meet-semilattice P with zero and a map f:PxP-->S such that f(x,z)<=f(x,y)vf(y,z) and x<=y implies that f(x,y)=0, for all x,y,z in P, together with the following conditions: (i) f(y,x)=0 implies that x=y, for all x<=y in P. (ii) For all x\leq y in P and all a,b in S, if f(y,x)=avb, then there
An-Cai Wu, Xin-Jian Xu, Zhi-Xi Wu, Ying-Hai Wang
We investigate the dynamics of random walks on weighted networks. Assuming that the edge's weight and the node's strength are used as local information by a random walker, we study two kinds of walks, weight-dependent walk and strength-dependent walk. Exact expressions for stationary distribution and average return time are derived and confirmed by c
F. Videbaek
The BRAHMS experiment at RHIC has measured the transverse single spin asymmetries in polarized pp induced pion production at RHIC. The results from the RHIC run-5 shows a significant asymmetry for pi+ and pi- at moderate xF. The trend of the data is in agreement with lower energy results while the absolute values are surprisingly large. The pT dependence is
PoNing Chen
We discuss the differential graded Lie algebra (DGLA) of Drinfeld modeled on the tensor algebra of the universal enveloping algebra of a Lie algebra g over any field K of characteristic zero. We explicitly analyze the first obstruction to the existence of the formality quasi-isomorphism for this DGLA. Our analysis implies the formality of the DGLA of Drinfel
Bing Zhang, Janusz Gil, Jaroslaw Dyks
Growing evidence suggests that some radio pulsars only act sporadically. These "part-time'' pulsars include long-term nulls, quasi-periodic radio flares in PSR B1931+24, as well as the so-called Rotating RAdio Transients (RRATs). Based on the assumption that these objects are isolated neutron stars similar to conventional radio pulsars, we discus
Efficient solvability of Hamiltonians and limits on the power of some quantum computational models
quant-phRolando Somma, Howard Barnum, Gerardo Ortiz, Emanuel Knill
We consider quantum computational models defined via a Lie-algebraic theory. In these models, specified initial states are acted on by Lie-algebraic quantum gates and the expectation values of Lie algebra elements are measured at the end. We show that these models can be efficiently simulated on a classical computer in time polynomial in the dimension of the
S. A. Haine, M. K. Olsen, J. J. Hope
We introduce a scheme for creating continuous variable entanglement between an atomic beam and an optical field, by using squeezed light to outcouple atoms from a BEC via a Raman transition. We model the full multimode dynamics of the atom laser beam and the squeezed optical field, and show that with appropriate two-photon detuning and two-photon Rabi freque
Preparation of nondegenerate coherent superpositions in a three-state ladder system assisted by Stark Shifts
quant-phN. Sangouard, L. P. Yatsenko, B. W. Shore, T. Halfmann
We propose a technique to prepare coherent superpositions of two nondegenerate quantum states in a three-state ladder system, driven by two simultaneous fields near resonance with an intermediate state. The technique, of potential application to enhancement of nonlinear processes, uses adiabatic passage assisted by dynamic Stark shifts induced by a third las
Y. D. Wang, H. T. Quan, Yu-xi Liu, C. P. Sun
Cavity quantum electrodynamic (QED) is studied for two strongly-coupled charge qubits interacting with a single-mode quantized field, which is provided by a on-chip transmission line resonator. We analyze the dressed state structure of this superconducting circuit QED system and the selection rules of electromagnetic-induced transitions between any two of th
Decoherence and localization in tunneling process under influence of one external degree of freedom
quant-phQuanlin Jie, Bambi Hu, Guangjong Dong
We investigate numerically the tunneling effect under influence of another particle in a double well system. Such influence from only one degree of freedom makes decoherence and quantum-classical transition, i.e., suppression of the tunneling effect. The decoherence happens even for cases that the influence is from a particle of very small mass, and it has v
Quanlin Jie, Dunhuan Liu
We reformulate the Lanczos algorithm for quantum wave function propagation in terms of variational principle. By including some basis states of previous time steps into the variational subspace, the resultant accuracy increases by several orders. Numerical errors of the alternative method accumulate much slower than that of the original Lanczos method. There
S. A. Moiseev, B. S. Ham
A dynamic quantum control of three-color lights in an optically dense medium is presented. We discuss how effectively to stop traveling three-color light pulses in the medium by using three control laser fields at near resonant transitions satisfying electromagnetically induced transparency. This opens a door to the quantum coherent control of multiple trave
N. Khaneja, C. Kehlet, S. J. Glaser, N. C. Nielsen
The efficiency of dipole-dipole coupling driven coherence transfer experiments in solid-state NMR spectroscopy of powder samples is limited by dispersion of the orientation of the internuclear vectors relative to the external magnetic field. Here we introduce general design principles and resulting pulse sequences that approach full polarization transfer eff
Daniel R. Terno
I discuss the role that relativistic considerations play in quantum information processing. First I describe how the causality requirements limit possible multi-partite measurements. Then the Lorentz transformations of quantum states are introduced, and their implications on physical qubits are described. This is used to describe relativistic effects in comm
Simulation Studies of Delta-ray Backgrounds in a Compton-Scatter Transition Radiation Detector
physics.ins-detJohn F. Krizmanic, Michael L. Cherry, Robert E. Streitmatter
In order to evaluate the response to cosmic-ray nuclei of a Compton-Scatter Transition Radiation Detector in the proposed ACCESS space-based mission, a hybrid Monte Carlo simulation using GEANT3 and an external transition radiation (TR) generator routine was constructed. This simulation was employed to study the effects of delta-ray production induced by hig
Calculation of Bit Error Ratio for Optically Pre-Amplified DPSK Receivers Using Optical Mach-Zehnder Interferometer Demodulation and Balanced Detection
physics.opticsXiupu Zhang, Zhenqian Qu, Lei Wang
This paper presents an analysis of how to calculate bit error ratio (BER) with physical explanation for optically pre-amplified DPSK receivers using optical Mach-Zehnder interferometer (MZI) demodulation and balanced detection. It is shown that BER calculation method for this kind of receivers is different from the conventional calculation method used widely