March 2006 arXiv papers — page 20

Richard F. Lebed

It has long been known that nonstrange baryon-meson scattering in the 1/N_c expansion of QCD greatly simplifies when expressed in terms of t-channel exchanges: The leading-order amplitudes satisfy the selection rule I_t = J_t. We show that I_t = J_t, as well as Y_t = 0, also hold for the leading amplitudes when the baryon and/or meson contain strange quarks,

Yu. A. Simonov

The 3d gluodynamics which governs the large T quark gluon plasma is studied in the framework of the field correlator method. Field correlators and spacial string tension are derived through the gluelump Green's functions. The glueball spectrum is calculated both in C=-1 as well as in C=+1 sectors, and multigluon bound states in the form of "gluon rin

V. P. Efrosinin, A. N. Khotyantsev

With usage of obvious mechanisms of quark currents the amplitudes of leptonic decaies of pseudoscalar mesons are investigated. The estimation for a constant of leptonic decay of the D+ meson is obtained, f_D+ ~ 0.23 GeV.

J. Iliopoulos

In the framework of the Standard Model the mass of the physical Higgs boson is an arbitrary parameter. In this note we examine whether it is possible to determine the ratio of $m_H /M$, where $M$ denotes any other mass in the theory, such as the $W$ or the $Z$-boson mass. We show that no such relation can be stable under renormalisation.

Alejandro Rivero

We revisit Sakurai's remark on the regularities of lepton-pair widths for mesons, extending the panorama to radiative $X \to γγ$ and total decays. The regularities persist, and somehow surprisingly some of them seem to relate with Fermi's constant -or $Z^0$-.

S. Ceci, A. Svarc, B. Zauner

In spite of prolonged polemics, the agreement on the existence of N(1710) P11 resonance has not until now been reached, and the Particle Data Group declares it as a 3-star resonance only. We show that the proper inclusion of inelastic channels in the coupled-channel formalism indisputably demands the existence of N(1710) P11 state, and that it presumably sta

A. D. Martin, W. J. Stirling, R. S. Thorne

We generate fixed three- and four-light-flavour sets of partons using MRST2004 partons as input. We show that it is important to set n_f=3 in the strong coupling, as well as in the splitting and coefficient functions, in order to obtain a consistent set of fixed-flavour partons. We compare the description of data using partons in both variable- and fixed-fla

Tevatron Electroweak Working Group

We summarize the top-quark mass measurements from the CDF and D0 experiments at Fermilab. We combine published Run-I (1992- 1996) measurements with the most recent preliminary Run-II (2001- present) measurements using up to 750/pb of data. Taking correlated uncertainties properly into account the resulting preliminary world average mass of the top quark is M

H1 Collaboration

The diffractive photoproduction of rho mesons, e p \to e rho Y, with large momentum transfer squared at the proton vertex, |t|, is studied with the H1 detector at HERA using an integrated luminosity of 20.1 pb^{-1}. The photon-proton centre of mass energy spans the range 75 < W < 95 GeV, the photon virtuality is restricted to Q^2 < 0.01 GeV^2 and the mass M_

Roldao da Rocha, E. Capelas de Oliveira

Using conformal coordinates associated with conformal relativity -- associated with de Sitter spacetime homeomorphic projection into Minkowski spacetime -- we obtain a conformal Klein-Gordon partial differential equation, which is intimately related to the production of quasi-normal modes (QNMs) oscillations, in the context of electromagnetic and/or gravitat

Charles H. -T. Wang

The newly found conformal decomposition in canonical general relativity is applied to drastically simplify the recently formulated parameter-free construction of spin-gauge variables for gravity. The resulting framework preserves many of the main structures of the existing canonical framework for loop quantum gravity related to the spin network and Thiemann&

Nikita A. Sakhanenko, George F. Luger, Hanna E. Makaruk, David B. Holtkamp

Shock physics experiments are often complicated and expensive. As a result, researchers are unable to conduct as many experiments as they would like - leading to sparse data sets. In this paper, Support Vector Machines for regression are applied to velocimetry data sets for shock damaged and melted tin metal. Some success at interpolating between data sets i

Alin Suciu

The unification algorithm is at the core of the logic programming paradigm, the first unification algorithm being developed by Robinson [5]. More efficient algorithms were developed later [3] and I introduce here yet another efficient unification algorithm centered on a specific data structure, called the Unification Table.

Maurizio Gabbrielli, Maria Chiara Meo

Constraint Handling Rules (CHR) are a committed-choice declarative language which has been designed for writing constraint solvers. A CHR program consists of multi-headed guarded rules which allow one to rewrite constraints into simpler ones until a solved form is reached. CHR has received a considerable attention, both from the practical and from the theore

D. Yu. Gusakova, A. A. Golubov, M. Yu. Kupriyanov, A. Buzdin

We developed the self-consistent method for the calculation of the density of states $N(ε)$ in the SF bilayers. It based on the quasi-classical Usadel equations and takes into account the suppression of superconductivity in the S layer due to the proximity effect with the F metal, as well as existing mechanisms of the spin dependent electron scattering. We d

A. P. Horsfield, D. R. Bowler, H. Ness, C. G. Sanchez

In this review we consider those processes in condensed matter that involve the irreversible flow of energy between electrons and nuclei that follows from a system being taken out of equilibrium. We survey some of the more important experimental phenomena associated with these processes, followed by a number of theoretical techniques for studying them. The t

Svetlana L. Bravina, Nicholas V. Morozovsky, Galina I. Dovbeshko, Elena D. Obraztsova

By photothermomodulatoin method the comparative study of thermal diffusivity of absorbing coating for sensitive elements of pyroelectric detectors of radiation formed from metal dispersion layer blacks, dielectric paint blacks and carbon nanotubes paint blacks has been performed. Prospects of using carbon nanotubes based black absorbing coatings for pyroelec

Shmuel M. Rubinstein, Meni Shay, Gil Cohen, Jay Fineberg

We perform real-time measurements of the net contact area between two blocks of like material at the onset of frictional slip. We show that the process of interface detachment, which immediately precedes the inception of frictional sliding, is governed by three different types of detachment fronts. These crack-like detachment fronts differ by both their prop

Elmar Bittner, Wolfhard Janke

The Sherrington-Kirkpatrick spin-glass model is investigated by means of Monte Carlo simulations employing a combination of the multi-overlap algorithm with parallel tempering methods. We investigate the finite-size scaling behaviour of the free-energy barriers which are visible in the probability density of the Parisi overlap parameter. Assuming that the me

A. Ossipov, J. H. Bardarson, C. W. J. Beenakker, J. Tworzydlo

The shot noise in the electrical current through a ballistic chaotic quantum dot with N-channel point contacts is suppressed for N --> infinity, because of the transition from stochastic scattering of quantum wave packets to deterministic dynamics of classical trajectories. The dynamics of the electron spin remains quantum mechanical in this transition, and

Wouter Montfrooij, Eric Svensson, Rolf Verberg, Roelof Crevecoeur

We present neutron scattering results for the dynamic response by superfluid and normal-fluid 4He and the results of a simple perturbation-theory analysis which allows us to describe all aspects of the observed behavior by considering only density fluctuations. We show that the three key features that are characteristic of the dynamic reponse of superfluid 4

I. S. Beloborodov, K. B. Efetov, A. V. Lopatin, V. M. Vinokur

A granular metal is an array of metallic nano-particles imbedded into an insulating matrix. Tuning the intergranular coupling strength a granular system can be transformed into either a good metal or an insulator and, in case of superconducting particles, experience superconductor-insulator transition. The ease of adjusting electronic properties of granular

D. Ivaneyko, J. Ilnytskyi, B. Berche, Yu. Holovatch

We present the results of Monte Carlo simulations for the critical dynamics of the three-dimensional site-diluted quenched Ising model. Three different dynamics are considered, these correspond to the local update Metropolis scheme as well as to the Swendsen-Wang and Wolff cluster algorithms. The lattice sizes of L=10-96 are analysed by a finite-size-scaling

A. Grigoriev, J. Skoeldberg, G. Wendin, Z. Crljen

We study the variation of electron transmission through Au-S-benzene-S-Au junctions and related systems as a function of the structure of the Au:S contacts. For junctions with semi-infinite flat Au(111) electrodes, the highly coordinated in-hollow and bridge positions are connected with broad transmission peaks around the Fermi level, due to a broad range of

G. M. Buendia, E. Machado, P. A. Rikvold

We present a study of the dynamical behavior of a Ziff-Gulari-Barshad model with CO desorption and lateral diffusion. Depending on the values of the desorption and diffusion parameters, the system presents a discontinuous phase transition between low and high CO coverage phases. We calculate several points on the coexistence curve between these phases. Inclu

E. Heinsalu, M. Patriarca, I. Goychuk, G. Schmid

Anomalous transport in a tilted periodic potential is investigated numerically within the framework of the fractional Fokker-Planck dynamics via the underlying CTRW. An efficient numerical algorithm is developed which is applicable for an arbitrary potential. This algorithm is then applied to investigate the fractional current and the corresponding nonlinear

Dong-Hee Kim, Hawoong Jeong

We study the structure of the load-based spanning tree (LST) that carries the maximum weight of the Erdos-Renyi (ER) random network. The weight of an edge is given by the edge-betweenness centrality, the effective number of shortest paths through the edge. We find that the LSTs present very inhomogeneous structures in contrast to the homogeneous structures o

P. Barthold, F. Hohls, N. Maire, K. Pierz

We have investigated the noise properties of the tunneling current through vertically coupled self-assembled InAs quantum dots. We observe super-Poissonian shot noise at low temperatures. For increased temperature this effect is suppressed. The super-Poissonian noise is explained by capacitive coupling between different stacks of quantum dots.

J. Schaefer, D. Schrupp, M. Preisinger, R. Claessen

The low-energy electronic properties of one-dimensional nanowires formed by Pt atoms on Ge(001) are studied with scanning tunneling microscopy down to the millivolt-regime. The chain structure exhibits various dimerized elements at high tunneling bias, indicative of a substrate bonding origin rather than a charge density wave. Unexpectedly, this dimerization

P. Capuzzi, P. Vignolo, F. Federici, M. P. Tosi

The work by T. K. Ghosh and K. Machida [cond-mat/0510160 and Phys. Rev. A 73, 013613 (2006)] on the sound velocity in a cylindrically confined Fermi superfluid obeying a power-law equation of state is shown to make use of an improper projection of the sound wave equation. This inaccuracy fully accounts for the difference between their results and those previ

Johannes Rödel

High-strain piezoelectric materials are often ceramics with a complicated constitution. In particular, PZT is used with compositions near to a so-called morphotropic phase boundary, where not only different variants of the same phase (domains), but different phases may coexist. Micro-mechanical models for ferroelectric ceramics would be much more realistic,

C. Dziurzik, G. I. Japaridze, A. Schadschneider, I. Titvinidze

In this paper we study the ground state phase diagram of a one-dimensional t-J-U model away from half-filling. In the large-bandwidth limit and for ferromagnetic exchange with easy-plane anisotropy a phase with gapless charge and massive spin excitations, characterized by the coexistence of triplet superconducting and spin density wave instabilities is reali

Alexander Shick, Ladislav Havela, Jindrich Kolorenc, Vaclav Drchal

The {\em around-mean-field} LSDA+U correlated band theory is applied to investigate the electronic and magnetic structure of $fcc$-Pu-Am alloys. Despite a lattice expansion caused by the Am atoms, neither tendency to 5$f$ localization nor formation of local magnetic moments on Pu atoms in Pu-Am alloys are found. The $5f$-manifolds in the alloys are calculate

Alexey S. Kalabukhov, Robert Gunnarsson, Johan Borjesson, Eva Olsson

Strontium titanate, SrTiO3, a widely used substrate material for electronic oxide thin film devices, has provided many interesting features. In a combination with a similar oxide material, LaAlO3, it has recently received great interest. It was suggested that two-dimensional electron gas is formed at the interface between SrTiO3 and LaAlO3, resulting in high

M. Sbragaglia, K. Sugiyama

We investigate the influence of boundary slip velocity in Newtonian fluids at finite Reynolds numbers. Numerical simulations with Lattice Boltzmann method (LBM) and Finite Differences method (FDM) are performed to quantify the effect of heterogeneous boundary conditions on the integral and local properties of the flow. Non linear effects are induced by the n

U. Staub, V. Scagnoli, A. M. Mulders, M. Janousch

Temperature dependences of a magnetic and an orbital Bragg reflection at the Mn L2 and L3 edges of La0.5Sr1.5MnO4 have been collected. The temperature evolution of the orbital reflection depend strongly on the x-ray energy and reflects the different order parameteres for orbitals and Jahn-Teller distortions. The gradual increase of the orbital order paramete

V. Scagnoli, U. Staub, A. M. Mulders, M. Janousch

Soft x-ray resonant scattering at the Ni L2,3 edges is used to test models of magnetic and orbital-ordering below the metal-insulator transition in NdNiO3. The large branching ratio of the L3 to L2 intensities of the (1/2,0,1/2) reflection and the observed azimuthal angle and polarization dependence originates from a non collinear magnetic structure. The abs

H. Ness, A. J. Fisher

We describe how to treat the interaction of travelling electrons with localised vibrational modes in nanojunctions. We present a multichannel scattering technique which can be applied to calculate the transport properties for realistic systems, and show how it is related to other methods that are useful in particular cases. We apply our technique to describe

Sungchul Kwon, S. Y. Yoon, Yup Kim

We investigate the kinetics of the $A+B \to 0$ reaction with long-range attractive interaction $V(r) \sim -r^{-2σ}$ between $A$ and $B$ or with the drift velocity $v \sim r^{-σ}$ in one dimension, where $r$ is the closest distance between $A$ and $B$. It is analytically show that the dynamical exponents for density of particles ($ρ$) and the size of domains

Shu Tanaka, Hosho Katsura, Naoto Nagaosa

The electronic states in incommensurate (IC) helical magnets are studied theoretically from the viewpoint of the localization/delocalization. It is found that in the multi-band system with relativistic spin-orbit interaction, the electronic wavefunctions show both the extended and localized natures along the helical axis depending on the orbital, helical wav

U. Zuelicke, E. Shimshoni

In two recent articles [PRL 90, 026802 (2003); PRB 69, 085307 (2004)], we developed a transport theory for an extended tunnel junction between two interacting fractional-quantum-Hall edge channels, obtaining analytical results for the conductance. Ponomarenko and Averin (PA) have expressed disagreement with our theoretical approach and question the validity

N. I. Gidopoulos

Density Functional Theory&#39;s Kohn-Sham (KS) potential emerges as the minimizing effective potential in an unconstrained variational scheme that does not involve fixing the unknown single-electron density. The physical content behind the virtual KS system, that of a non-interacting electronic system representing optimally the interacting one, is brought to

Qian Wang, H. -Y. Chen, C. -R. Hu, C. S. Ting

The Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) states for two-dimensional s- and d-wave superconductors (s- and d-SC) are self-consistently studied under an in-plane magnetic field. While the stripe solution of the order parameter (OP) is found to have lower free energy in s-SC, a square lattice solution appears to be energetically more favorable in the case of

Olav F. Syljuasen, Sudip Chakravarty

The simplest quantum generalization of the six-vertex model describes fluctuations of the order parameter of the d-density wave (DDW), believed to compete with superconductivity in the high-Tc superconductors. The ground state of this model undergoes a first order transition from the DDW phase to a resonating plaquette phase as the quantum fluctuations are i

Narayani Choudhury, R. E. Cohen, Eric J. Walter

We report first principles density functional calculations of the Born effective charges and electronic dielectric tensors for the relaxor PMN (PbMg1/3Nb2/3O3). Visualization of the Born charge tensors as charge ellipsoids have provided microscopic insights on the factors governing piezoelectric enhancements with polarization rotation. Several 15 and 30-atom

C. W. Engelbracht, P. Kundurthy, K. D. Gordon, G. H. Rieke

We present new images (groundbased optical and mid-infrared (MIR) from the Spitzer Space Telescope) and spectra (from Spitzer) of the archetypal starburst galaxy M 82. The Spitzer data show that the MIR emission extends at least 6 kpc along the minor axis of the galaxy. We use the optical and infrared data to demonstrate that the extended emission is dominat

E. Xanthopoulos, A. H. Thean, A. Pedlar, A. M. S. Richards

High resolution MERLIN 5 GHz observations (0.04&#34;) of 7 Seyfert galaxies, selected as the ones previously showing evidence of collimated ejection, have been compared with high resolution archive HST data. The radio maps reveal rich structures in all the galaxies. NGC 2639 and TXFS 2226-184 have multiple knot parsec-scale extended structures, Mrk 1034, Mrk

E. Xanthopoulos, R. H. Becker, W. H. deVries, R. L. White

Using the final version of the VLA FIRST survey (Becker et al. 2003), the optical Sloan Digital Sky Survey Data Release 3 (DR3) quasar list and a series of carefully selected criteria, we have defined the largest homogeneous population of double-lobed sources. With the precise sample definition, the increased depth and sensitivity of the survey data, the lar

Pearl Sandick, Keith A. Olive, Frederic Daigne, Elisabeth Vangioni

We consider the stochastic background of gravitational waves produced by an early generation of Population III stars coupled with a normal mode of star formation at lower redshift. The computation is performed in the framework of hierarchical structure formation and is based on cosmic star formation histories constrained to reproduce the observed star format

Jeremy L. Tinker, Peder Norberg, David H. Weinberg, Michael S. Warren

(Abridged) We make predictions for the pairwise velocity dispersion (PVD) of galaxies with models that are constrained to match the projected correlation function and luminosity function of galaxies in the Two-Degree Field Galaxy Redshift Survey (2dFGRS). We use these data to constrain the halo occupation distribution (HOD), then calculate the PVD by populat

Gabrijela Zaharijas, Dan Hooper

Atmospheric Cerenkov Telescopes, including HESS and MAGIC, have detected a spectrum of gamma-rays from the galactic center region which extends from $\sim$200 GeV or lower, to at least $\sim$10 TeV. Although the source of this radiation is not yet known, the spectrum appears to behave as a simple power-law, which is not the expectation for gamma-rays generat

Marek Szydlowski, Aleksandra Kurek

It is described dynamics of a large class of accelerating cosmological models in terms of dynamical systems of the Newtonian type. The evolution of the models is reduced to the motion of a particle in a potential well parameterized by the scale factor. This potential function can be reconstructed from distant supernovae type Ia data and many cosmological mod

Peter Nugent, Mark Sullivan, Richard Ellis, Avishay Gal-Yam

We present the first high-redshift Hubble diagram for Type II-P supernovae (SNe II-P) based upon five events at redshift up to z~0.3. This diagram was constructed using photometry from the Canada-France-Hawaii Telescope Supernova Legacy Survey and absorption line spectroscopy from the Keck observatory. The method used to measure distances to these supernovae

Estela M. Reynoso, Simon Johnston, Anne J. Green, Baerbel S. Koribalski

We have observed the supernova remnant (SNR) G290.1-0.8 in the 21-cm HI line and the 20-cm radio continuum using the Australia Telescope Compact Array (ATCA). The HI data were combined with data from the Southern Galactic Plane Survey to recover the shortest spatial frequencies. In contrast, HI absorption was analyzed by filtering extended HI emission, with

G. Fabbiano, D. -W. Kim, T. Fragos, V. Kalogera

We report recent Chandra observations of the ULX in the elliptical galaxy NGC3379 that clearly detect two flux variability cycles. Comparing these data with the Chandra observation of ~5yr ago, we measure a flux modulation with a period of ~12.6hr. Moreover, we find that the emission undergoes a correlated spectral modulation, becoming softer at low flux. We

MAGIC collaboration, J. Albert, E. Aliu, H. Anderhub

The MAGIC collaboration has studied the high peaked BL-Lac object 1ES1218+30.4 at a redshift z = 0.182, using the MAGIC imaging air Cherenkov telescope located on the Canary island of La Palma. A gamma-ray signal was observed with 6.4sigma significance. The differential energy spectrum for an energy threshold of 120GeV can be fitted by a simple power law yie

Yuichi Terashima, Hirohiko Inoue, Andrew S. Wilson

We present the results of a search for optical identifications of ultraluminous X-ray sources (ULXs) in M51 by using mosaic images taken with the Hubble Space Telescope Advanced Camera for Surveys in filters F435W (B), F555W (V), F814W (I), and F658N (Halpha). Our sample consisting of nine ULXs is defined by analyzing the three Chandra observations of M51 pe

J. D. Hartman, D. Bersier, K. Z. Stanek, J. -P. Beaulieu

We have conducted a variability survey of the local group galaxy M33 using g', r', and i' observations from 27 nights spanning 17 months made with the MegaPrime/MegaCam instrument on the 3.6 m CFHT telescope. We identify more than 36000 variable sources with g',r',i' < 24 out of approximately 2 million point sources in a one square degree field of view. This

J. Silk, L. Stodolsky

Bursts of weakly interacting particles such as neutrinos or even more weakly interacting particles such as wimps and gravitons from the very early universe would offer a much deeper ``look back time&#39;&#39; to early epochs than is possible with photons. We consider some of the issues related to the existence of such bursts and their detectability. Characte

Mofazzal Azam, M. Sami

The string inspired higher dimensional theories suggest modification of Newton&#39;s law at submillimeter length scales. Inter-particle distances in white dwarf and neutron stars are $10^{-10} cms$ and $10^{-13} cms$ respectively, and therefore, the effects of of short distance corrections to gravity deserve investigation. We show, by carrying out explicit a

S. Mieske, M. J. West, C. Mendes de Oliveira

We present a photometric search for UCD candidates in the nearby galaxy group NGC 1023 (d=11 Mpc) -- the poorest environment searched for UCDs yet --, based on wide field imaging with CFHT. After photometric and morphological selection, we obtain a sample of 21 UCD candidates with -12<M_V<-11 mag, if located at NGC 1023&#39;s distance. From spectroscopy take

E. Zackrisson, N. Bergvall, T. Marquart, G. Ostlin

We present BVI photometry and long-slit Halpha rotation curve data obtained with ESO VLT/FORS2 for six low surface brightness galaxies with extremely blue colours and very faint central regions. We find no evidence for a steep central density cusp of the type predicted by many N-body simulations of cold dark matter (CDM) halos. Our observations are instead c

W. A. Barkhouse, P. J. Green, A. Vikhlinin, D. -W. Kim

We present a survey of serendipitous extended X-ray sources and optical cluster candidates from the Chandra Multi-wavelength Project (ChaMP). Our main goal is to make an unbiased comparison of X-ray and optical cluster detection methods. In 130 archival Chandra pointings covering 13 square degrees, we use a wavelet decomposition technique to detect 55 extend

D. M. Peterson, C. A. Hummel, T. A. Pauls, J. T. Armstrong

Vega, the second brightest star in the northern hemisphere, serves as a primary spectral type standard. While its spectrum is dominated by broad hydrogen lines, the narrower lines of the heavy elements suggested slow to moderate rotation, giving confidence that the ground-based calibration of its visibile spectrum could be safely extrapolated into the ultrav

Paolo A. Mazzali, Jinsong Deng, Elena Pian, Daniele Malesani

The Gamma-Ray Burst 031203 at a redshift z=0.1055 revealed a highly reddened Type Ic Supernova, SN 2003lw, in its afterglow light. This is the third well established case of a link between a long-duration GRB and a type Ic SN. The SN light curve is obtained subtracting the galaxy contribution and is modelled together with two spectra at near-maximum epochs.

Avishai Dekel, Thomas, J. Cox

We address the deviations of the scaling relations of elliptical galaxies from the expectations based on the virial theorem and homology, including the &#34;tilt&#34; of the &#34;fundamental plane&#34; and the steep decline of density with mass. We show that such tilts result from dissipative major mergers once the gas fraction available for dissipation decl

J. Jurcsik, B. Szeidl, Á. Sódor, I. Dékány

Extended BV(RI)c CCD observations of SS Cnc, a short period RRab star are presented. Nearly 1400 data points in each band have been obtained spanning over 79 days during the spring of 2005. The star exhibits light curve modulation, the so called Blazhko effect with small amplitude (B maximum brightness varies 0.1 mag) and with the shortest modulation period

Mario Ziman

We address the problem of quantum process tomography with the preparators producing states correlated with the environmental degrees of freedom that play role in the system-environment interactions. We discuss the physical situations, in which the dynamics is described by nonlinear, or noncompletely positive transformations. In particular, we show that arbit

Xiaobo Liu

An earlier article with Francis Bonahon introduced new invariants for pseudo-Anosov diffeomorphisms of surface, based on the representation theory of the quantum Teichmuller space. We explicity compute these quantum hyperbolic invariants in the case of the 1-puncture torus and the 4-puncture sphere.

Ciamac C. Moallemi, Benjamin Van Roy

We propose consensus propagation, an asynchronous distributed protocol for averaging numbers across a network. We establish convergence, characterize the convergence rate for regular graphs, and demonstrate that the protocol exhibits better scaling properties than pairwise averaging, an alternative that has received much recent attention. Consensus propagati

Emanuel Milman

We remark that an easy combination of two known results yields a positive answer, up to log(n) terms, to a duality conjecture that goes back to Pietsch. In particular, we show that for any two symmetric convex bodies K,T in R^n, denoting by N(K,T) the minimal number of translates of T needed to cover K, one has: N(K,T) <= N(T*,(C log(n))^{-1} K*)^{C log(n) l

Zhou Zhang

In this work, we study Monge-Ampere equations over closed Kähler manifolds with degenerated cohomology classes. Classic results and arguments in pluripotential theory are generalized a little bit to be applied to our situation.

Garrelt Mellema, Ilian T. Iliev, Ue-Li Pen, Paul R. Shapiro

We present detailed predictions for the redshifted 21cm signal from the epoch of reionization. These predictions are obtained from radiative transfer calculations on the results of large scale (100/h Mpc), high dynamic range, cosmological simulations. We consider several scenarios for the reionization history, of both early and extended reionization. From th

Dmitrij V. Soroka, Vyacheslav A. Soroka

This paper was withdrawn by the editors of SIGMA as it essentially coincides with Phys. Lett. B 451 (1999), no. 3-4, 349-353.

D. N. Spergel, R. Bean, O. Doré, M. R. Nolta

A simple cosmological model with only six parameters (matter density, Omega_m h^2, baryon density, Omega_b h^2, Hubble Constant, H_0, amplitude of fluctuations, sigma_8, optical depth, tau, and a slope for the scalar perturbation spectrum, n_s) fits not only the three year WMAP temperature and polarization data, but also small scale CMB data, light element a

W. Kavanagh, I. Booth

Slowly evolving horizons are trapping horizons that are &#34;almost&#34; isolated horizons. This paper reviews their definition and discusses several spacetimes containing such structures. These include certain Vaidya and Tolman-Bondi solutions as well as (perturbatively) tidally distorted black holes. Taking into account the associated mass scales, they als

V. S. Prasanna Rajan

The Scaled Boundary Finite Element Method is a novel semi-analytical method jointly developed by Chongmin Song and John P Wolf to solve problems in elastodynamics and allied problems in civil engineering. This novel method has been recently reformulated for the following categories of problems in electromagnetics: (1) Determination of Eigen values of metalli

Lajos Diosi

Time-continuous wavefunction collapse mechanisms n o t restricted to markovian approximation have been found only a few years ago, and have left many issues open. The results apply formally to the standard relativistic quantum-electrodynamics. I present a generalized Schrodinger equation driven by a certain complex stochastic field. The equation reproduces t

F. Pakovich

In this paper we give a solution of the following problem: under what conditions on infinite compact sets $K_1,K_2\subset \C$ and polynomials $f_1,$ $f_2$ the preimages $f_1^{-1}\{K_1\}$ and $f_2^{-1}\{K_2\}$ coincide. Besides, we investigate some related questions. In particular, we show that polynomials sharing an invariant compact set distinct from a poin

Ragab M. Gad

We calculated the energy and momentum densities of stiff fluid solutions, using Einstein, Bergmann-Thomson and Landau-Lifshitz energy-momentum complexes, in both general relativity and teleparallel gravity. In our analysis we get different results comparing the aforementioned complexes with each other when calculated in the same gravitational theory, either

Swarnali Bandopadhyay, Yoav Etzioni, Doron Cohen

The Landauer conductance of a two terminal device equals to the number of open modes in the weak scattering limit. What is the corresponding result if we close the system into a ring? Is it still bounded by the number of open modes? Or is it unbounded as in the semi-classical (Drude) analysis? It turns out that the calculation of the mesoscopic conductance i

S. K. Pandey, R. Bindu, Ashwani Kumar, S. Khalid

The experimental Mn K-edge x-ray absorption spectra of La$_{1-x}$Sr$_x$MnO$_{3}$, $x$ = 0 - 0.7 are compared with the band structure calculations using spin polarized density functional theory. It is explicitly shown that there is a correspondence between the inflection point on the absorption edge and the centre of gravity of the unoccupied Mn 4$p$-band. Th

Warren E. Pickett

The vision of ``room temperature superconductivity&#39;&#39; has appeared intermittently but prominently in the literature since 1964, when W. A. Little and V. L. Ginzburg began working on the `problem of high temperature superconductivity&#39; around the same time. Since that time the prospects for room temperature superconductivity have varied from gloom (

Arthur V. Straube, Dmitry V. Lyubimov, Sergey V. Shklyaev

The averaged dynamics of various two-phase systems in a high-frequency vibration field is studied theoretically. The continuum approach is applied to describe such systems as solid particle suspensions, emulsions, bubbly fluids, when the volume concentration of the disperse phase is small and gravity is insignificant. The dynamics of the disperse system is c

Hong-Zhi Chen, Bin Chen

We discuss the matrix model in a class of 11D time dependent supersymmetric backgrounds as obtained in hep-th/0508191 . We construct the matrix model action through the matrix regularization of the membrane action in the background. We show that the action is exact to all order of fermionic coordinates. Furthermore We discuss the fuzzy sphere solutions in th

Keiichi Kimura, Akira Takamura, Tadashi Yoshikawa

We introduce a new index of the leptonic CP phase dependence $I_{\rm CP}$ and derive the maximal condition for this index in a simple and general form. $I_{\rm CP}\simeq 100%$ may be realized even in the JPARC experiment. In the case that the 1-3 mixing angle can be observed in the next generation reactor experiments, namely $\sin^2 2θ_{13}>0.01$, and nevert

Michael A. Nielsen, Mark R. Dowling, Mile Gu, Andrew C. Doherty

Quantum computers hold great promise, but it remains a challenge to find efficient quantum circuits that solve interesting computational problems. We show that finding optimal quantum circuits is essentially equivalent to finding the shortest path between two points in a certain curved geometry. By recasting the problem of finding quantum circuits as a geome

Michael A. Nielsen, Mark R. Dowling, Mile Gu, Andrew C. Doherty

We prove upper and lower bounds relating the quantum gate complexity of a unitary operation, U, to the optimal control cost associated to the synthesis of U. These bounds apply for any optimal control problem, and can be used to show that the quantum gate complexity is essentially equivalent to the optimal control cost for a wide range of problems, including

Sang-Hoon Kim, Chul Koo Kim, Mukunda P. Das

A ground state energy density of an interacting dilute Bose gas system is studied in the canonical transformation scheme. It is shown that the transformation scheme enables us to calculate a higher order correction of order $n a^3$ in the particle depletion and ground state energy density of a dilute Bose gas system, which corresponds to the density fluctuat

Wei Liu, Siming Liu, Yan Wei Jiang, Vahe&#39; Petrosian

We present analyses of the spatial and spectral evolution of hard X-ray emission observed by {\it RHESSI} during the impulsive phase of an M1.7 flare on 2003 November 13. In general, as expected, the loop top (LT) source dominates at low energies while the footpoint (FP) sources dominate the high energy emission. At intermediate energies, both the LT and FPs

Yuuiti Sendouda, Shigehiro Nagataki, Katsuhiko Sato

The mass spectrum of the primordial black holes formed by density perturbation in the radiation-dominated era of the Randall-Sundrum type-2 cosmology is given. The spectrum coincides with standard four-dimensional one on large scales but the deviation is apparent on smaller scales. The mass spectrum is initially softer than standard four-dimensional one, whi

Mario Castagnino

An alternative explanation of the decoherence in the Casati-Prosen model is presented. It is based on the Self Induced Decoherence formalism extended to non-integrable systems.

Richard Jozsa

We consider recent works on the simulation of quantum circuits using the formalism of matrix product states and the formalism of contracting tensor networks. We provide simplified direct proofs of many of these results, extending an explicit class of efficiently simulable circuits (log depth circuits with 2-qubit gates of limited range) to the following: let

M. Bache, A. Gatti, E. Brambilla, D. Magatti

Comment on A.F. Abouraddy, P.R. Stone, A.V. Sergienko, B.E.A. Saleh, and M.C. Teich, ``Entangled-Photon Imaging of a Pure Phase Object,&#39;&#39; Phys. Rev. Lett. 93, 213903 (2004). Unpublished (rejected by Physical Review Letters), but for a publication holding main points see A. Gatti, M. Bache, D. Magatti, E. Brambilla, F. Ferri, and L.A. Lugiato &#34;Coh

Ovidiu Radulescu, Sergei Vakulenko

We discuss several qualitative properties of the solutions of reaction-diffusion systems and equations of the form $u_t = ε^2 D Δu + f(u,x,εt)$, that are used in modeling pattern formation. We analyze the diffusion neutral and the diffusion dependent situations that, in the time autonomous case, are distinguished by considering the attractors of the shorted

Uygar Ozesmi

Sustainability of ecosystems & ecosystem management are increasingly accepted societal goals. Can conservation programs be improved by incorporating local people&#39;s understanding of ecosystems? The Kizilirmak Delta is one of Turkey&#39;s most important wetland complexes. It is also one of the most productive agricultural deltas in Turkey. We obtained 31 c

Brigitte Pallmann, A. D. Barbour, D. J. Hosken, P. I. Ward

When conducting inter-species regression analyses, the phylogenetic relationships between the individual species need to be taken into account. In this paper, a procedure for conducting such analyses is proposed, which only requires the use of a measure of relationship between pairs of species, rather than a complete phylogeny, and which at the same time ass

C. D. Havey, Mark Eberhart, T. Jones, Kent J. Voorhees

The coupling of an electron monochromator (EM) to a mass spectrometer (MS) has created a new analytical technique, EM-MS, for the investigation of electrophilic compounds. This method provides a powerful tool for molecular identification of compounds contained in complex matrices, such as environmental samples. EM-MS expands the application and selectivity o

Dmitry V. Lyubimov, Arthur V. Straube, Tatyana P. Lyubimova

Interaction of particles of dust with vortex convective flows is under theoretical consideration. It is assumed that the volume fraction of solid phase is small, variations of density due to nonuniform distribution of particles and those caused by temperature nonisothermality of medium are comparable. Equations for the description of thermal buoyancy convect

Ginestra Bianconi, Andrea De Martino, Fernando F. Ferreira, Matteo Marsili

We study analytically and numerically Minority Games in which agents may invest in different assets (or markets), considering both the canonical and the grand-canonical versions. We find that the likelihood of agents trading in a given asset depends on the relative amount of information available in that market. More specifically, in the canonical game playe