December 2006 arXiv papers — page 3

Bing-Long Chen, Philippe G. LeFloch

Motivated by the application to spacetimes of general relativity we investigate the geometry and regularity of Lorentzian manifolds under certain curvature and volume bounds. We establish several injectivity radius estimates at a point or on the past null cone of a point. Our estimates are entirely local and geometric, and are formulated via a reference Riem

Toshiki Nakashima

We shall realize certain affine geometric crystal of type $G^{(1)}_2$ explicitly in the fundamental representation $W(\varpi_1)$. Its explicit form is rather complicated but still keeps a positive structure.

Pablo A. Ferrari, Claudio Landim, Valentin V. Sisko

A family of m independent identically distributed random variables indexed by a chemical potential ϕ\in[0,γ] represents piles of particles. As ϕincreases to γ, the mean number of particles per site converges to a maximal density ρ_c<\infty. The distribution of particles conditioned on the total number of particles equal to n does not depend on ϕ(canonical en

Andrzej Derdzinski, Tadeusz Januszkiewicz

Totally real immersions $f$ of a closed real surface $Σ$ in an almost complex surface $M$ are completely classified, up to homotopy through totally real immersions, by suitably defined homotopy classes $\frak{M}(f)$ of mappings from $Σ$ into a specific real 5-manifold $E(M)$, while $\frak{M}(f)$ themselves are subject to a single cohomology constraint. This

Benedikt Steinar Magnusson, Ragnar Sigurdsson

We prove a disc formula for the weighted Siciak-Zahariuta extremal function $V_{X,q}$ for an upper semicontinuous function $q$ on an open connected subset $X$ in $\C^n$. This function is also known as the weighted Green function with logaritmic pole at infinity and weighted global extremal function.

Ping-Shun Chan

In the first part of the book, we classify the automorphic representations of {\rm GSp}(2) which are invariant under tensor product with a given quadratic idèle class character, via the lifting of automorphic representations of twisted endoscopic groups. In the second part of the book, we classify the admissible representations of {\rm GSp}(2, k), k a p-adic

D. A. Popov

Spectral problem for a family of periodic Sturm--Liouville problems \[ u&#39;&#39;+λ^2(a(x)-a)u=0 \] depending on the parameter (a\in\mathbb R) is considered. An interpolation formula describing the behaviour of the branches of the spectrum in the transition from a definite problem to indefinite one is obtained.

Paulo Amorim, Matania Ben-Artzi, Philippe G. LeFloch

This paper investigates some properties of entropy solutions of hyperbolic conservation laws on a Riemannian manifold. First, we generalize the Total Variation Diminishing (TVD) property to manifolds, by deriving conditions on the flux of the conservation law and a given vector field ensuring that the total variation of the solution along the integral curves

Matania Ben-Artzi, Philippe G. LeFloch

Motivated by many applications (geophysical flows, general relativity), we attempt to set the foundations for a study of entropy solutions to nonlinear hyperbolic conservation laws posed on a (Riemannian or Lorentzian) manifold. The flux of the conservation laws is viewed as a vector-field on the manifold and depends on the unknown function as a parameter. W

Eli Bagno, Ayelet Butman, David Garber

We define an excedance number for the multi-colored permutation group, i.e. the wreath product of Z_{r_1} x ... x Z_{r_k} with S_n, and calculate its multi-distribution with some natural parameters. We also compute the multi-distribution of the parameters exc(pi) and fix(pi) over the sets of involutions in the multi-colored permutation group. Using this, we

Pedro Fonseca, Alexander Zamolodchikov

This paper is our progress report on the project &#34;Ising spectroscopy&#34;, devoted to systematic study of the mass spectrum of particles in 2D Ising Field Theory in a magnetic field. Here we address the low-temperature regime, and develop quantitative approach based on the idea (originally due to McCoy and Wu) of particles being the &#34;mesons&#34;, con

Patricio Gaete, Iván Schmidt

For a recently proposed alternative to the traditional axion model, we study its long distance behavior, in particular the confinement versus screening issue, and show that a compactified version of this theory can be further mapped into the massive Schwinger model. Our calculation is based on the gauge-invariant but path-dependent variables formalism. This

K. A. Milton, I. Cavero-Pelaez, K. Kirsten

The effects of quantum fluctuations in fields confined by background configurations may be simply and transparently computed using the Green&#39;s function approach pioneered by Schwinger. Not only can total energies and surface forces be computed in this way, but local energy densities, and in general, all components of the vacuum expectation value of the e

H. Lu, C. N. Pope, E. Sezgin

The reduction of ten-dimensional heterotic supergravity with Yang-Mills symmetry group K is performed on an arbitrary n-dimensional group manifold G. The reduction involves a nonvanishing 3-form flux, and the Lie algebra of G must have traceless structure constants to ensure the consistency of the reduction at the level of the action. A large class of gauged

Fred Cooper, Gouranga C. Nayak

We study the Schwinger mechanism for the pair production of fermions in the presence of an arbitrary time-dependent background electric field E(t) by directly evaluating the path integral. We obtain an exact non-perturbative result for the probability of fermion-antifermion pair production per unit time per unit volume per unit transverse momentum (of the fe

F. Donato, N. Fornengo, M. Schelke

The possibility to use $γ$--ray data from the Galactic Center (GC) to constrain the cosmological evolution of the Universe in a phase prior to primordial nucleosyntesis, namely around the time of cold dark matter (CDM) decoupling, is analyzed. The basic idea is that in a modified cosmological scenario, where the Hubble expansion rate is enhanced with respect

G. S. Sharov

The closed relativistic string carrying two point-like masses is considered as the model of a glueball with two constituent gluons. Here the gluon-gluon interaction is simulated by a pair of strings. For this system exact solutions of classical equations of motions are obtained. They describe rotational states of the string resulting in the set of quasilinea

Matthew Mewes, Alexander Petroff

Electromagnetic resonant cavities form the basis for a number modern tests of Lorentz invariance. The geometry of most of these experiments implies unsuppressed sensitivities to parity-even Lorentz violations only. Parity-odd violations typically enter through suppressed boost effects, causing a reduction in sensitivity by roughly four orders of magnitude. H

Zurab Berezhiani

The baryonic and dark matter fractions in the universe can be both generated by the same baryogenesis mechanism, simultaneously and with comparable amounts, if dark matter is constituted by the baryons of the mirror world, a parallel hidden sector with the same (or similar) microphysics as that of the observable world.

M. Spira, P. Niezurawski, M. Krawczyk, A. F. Zarnecki

Measurement of the heavy neutral MSSM Higgs bosons H and A production in the process gamma gamma --> A, H --> b anti-b at the Photon Linear Collider has been considered in two independent analyses for the parameter range corresponding to the so-called &#34;LHC wedge&#34;. Significantly different conclusions were obtained; signal to background ratio 36 vs 2.

Neil Russell

The Standard-Model Extension, or SME, is a general framework for the study of Lorentz violation in physics. A broad variety of experiments is able to access the SME coefficient space. This proceedings briefly summarizes theory and experiments aimed at testing Special Relativity by measuring these coefficients.

Victor Flambaum, Michael Kuchiev

The charge density of vector particles, for example W, may change sign. The effect manifests itself even for a free propagation; when the energy of the W-boson is higher than sqrt{2}m and the standing-wave is considered the charge density oscillates in space. The charge density of W also changes sign in close vicinity of a Coulomb center. The dependence of t

M. Göckeler, Ph. Hägler, R. Horsley, Y. Nakamura

We present the first calculation in lattice QCD of the lowest two moments of transverse spin densities of quarks in the nucleon. They encode correlations between quark spin and orbital angular momentum. Our dynamical simulations are based on two flavors of clover-improved Wilson fermions and Wilson gluons. We find significant contributions from certain quark

Alexander Burinskii

Kerr-Schild formalism is generalized by incorporation of the Kerr Theorem with polynomials of higher degrees in $Y\in CP^1.$ It leads to multisheeted twistor spaces and multiparticle solutions.

Janusz Karkowski, Bogusz Kinasiewicz, Patryk Mach, Edward Malec

The spherically symmetric steady accretion of polytropic perfect fluids onto a black hole is the simplest flow model that can demonstrate the effects of backreaction. Backreaction keeps intact most of the characteristics of the sonic point. For any such system the mass accretion rate achieves maximal value when the mass of the fluid is 1/3 of the total mass.

Elcio Abdalla, Davi Giugno

In the current paper we present some new data on the issue of quasi-normal modes (QNMs) of uniform, neutron and quark stars. These questions have already been addressed in the literature before, but we have found some interesting features that have not been discussed so far. We have increased the range of frequency values for the scalar and axial perturbatio

Z. Salman, A. I. Mansour, K. H. Chow, M. Beaudoin

Depth-controlled $β$-NMR was used to study highly spin-polarized $^8$Li in a Cu film of thickness 100 nm deposited onto a MgO substrate. The positive Knight Shifts and spin relaxation data show that $^8$Li occupies two sites at low temperatures, assigned to be the substitutional ($S$) and octahedral ($O$) interstitial sites. Between 50 to 100 K, there is a s

J. W. Lynn, D. N Argyriou, Y. Ren, Y. Chen

Neutron elastic, inelastic and high energy x-ray scattering techniques are used to explore the nature of the polaron order and dynamics in La0.7Ca0.3MnO3. Static polaron correlations develop within a narrow temperature regime as the Curie temperature is approached from low temperatures, with a nanoscale correlation length that is only weakly temperature depe

Hans-Andreas Engel, Jacob M. Taylor, Mikhail D. Lukin, Atac Imamoglu

We describe an opto-electronic structure in which charge and spin degrees of freedom in electrical gate-defined quantum dots can be coherently coupled to light. This is achieved via electron-electron interaction or via electron tunneling into a proximal self-assembled quantum dot. We illustrate potential applications of this approach by considering several q

A. R. Akhmerov, C. W. J. Beenakker

Because the valleys in the band structure of graphene are related by time-reversal symmetry, electrons from one valley are reflected as holes from the other valley at the junction with a superconductor. We show how this Andreev reflection can be used to detect the valley polarization of edge states produced by a magnetic field. In the absence of intervalley

Marian Grendar, Robert K. Niven

Sanov&#39;s Theorem and the Conditional Limit Theorem (CoLT) are established for a multicolor Polya Eggenberger urn sampling scheme, giving the Polya divergence and the Polya extension to the Maximum Relative Entropy (MaxEnt) method. Polya MaxEnt includes the standard MaxEnt as a special case. The universality of standard MaxEnt - advocated by an axiomatic a

Roberto F. S. Andrade, José G. V. Miranda, Suani T. R. Pinho, Thierry Petit Lobão

A concept of higher order neighborhood in complex networks, introduced previously (PRE \textbf{73}, 046101, (2006)), is systematically explored to investigate larger scale structures in complex networks. The basic idea is to consider each higher order neighborhood as a network in itself, represented by a corresponding adjacency matrix. Usual network indices

S. H. Noskowicz, O. Bar-Lev, D. Serero, I. Goldhirsch

The expansion of the velocity distribution function for the homogeneous cooling state (HCS) in a Sonine polynomial series around a Maxwellian is shown to be divergent, though Borel resummable. A convergent expansion for the HCS has been devised and employed to obtain the HCS velocity distribution function and (using it) the linear transport coefficients for

G. E. Astrakharchik, J. Boronat, J. Casulleras, I. L. Kurbakov

We consider a homogeneous 2D Bose gas with repulsive dipole-dipole interactions. The ground-state equation of state, calculated using the Diffusion Monte Carlo method, shows quantitative differences with predictions of commonly used Gross-Pitaevskii mean-field theory. The static structure factor, pair distribution function and condensate fraction are calcula

D. Baeriswyl, D. Eichenberger, B. Gut

A refined variational wave function for the two-dimensional repulsive Hubbard model is studied numerically, with the aim of approaching the difficult crossover regime of intermediate values of U. The issue of a superconducting ground state with d-wave symmetry is investigated for an average electron density n=0.8125 and for U=8t. Due to finite-size effects a

N. A. Gippius, I. A. Shelykh, D. D. Solnyshkov, S. S. Gavrilov

New effects of polarization multistability and polarization hysteresis in a coherently driven polariton condensate in a semiconductor microcavity are predicted and theoretically analyzed. The multistability arises due to polarization-dependent polariton-polariton interactions and can be revealed in polarization resolved photoluminescence experiments. The pum

M. Vengalattore, J. M. Higbie, S. R. Leslie, J. Guzman

We demonstrate a precision magnetic microscope based on direct imaging of the Larmor precession of a $^{87}$Rb spinor Bose-Einstein condensate. This magnetometer attains a field sensitivity of 8.3 pT/Hz$^{1/2}$ over a measurement area of 120 $μ$m$^2$, an improvement over the low-frequency field sensitivity of modern SQUID magnetometers. The corresponding ato

Mona Zebarjadi, Ceyhun Bulutay, Keivan Esfarjani, Ali Shakouri

A modified algorithm is proposed to include Pauli exclusion principle in Monte-Carlo simulations. This algorithm has significant advantages to implement in terms of simplicity, speed and memory storage. We show that even in moderately high applied fields, one can estimate electronic distribution with a shifted Fermi sphere without introducing significant err

L. Velazquez

According to the recently obtained thermodynamic uncertainty relation, the microcanonical regions with a negative heat capacity can be accessed within a canonical-like description by using a thermostat with a fluctuating inverse temperature. This far-reaching conclusion is used in this Letter for enhancing the potentialities of the well-known Swendsen-Wang c

Zenji Hiroi, Jun-Ichi Yamaura, Shigeki Yonezawa, Hisatomo Harima

Chemical trends of fundamental superconducting parameters and normal-state properties are described for a family of pyrochlore oxide superconductors. Particularly, the change of Tc from 1.0 K for alpha-pyrochlore Cd2Re2O7 to 3.3 K (A = Cs), 6.3 K (Rb), and 9.6 K (K) for beta-pyrochlore AOs2O6 is discussed on the basis of the conventional BCS scheme. Enhanced

M. Kiguchi, R. Stadler, I. S. Kristensen, D. Djukic

Stable, single-molecule conducting-bridge configurations are typically identified from peak structures in a conductance histogram. In previous work on Pt with H$_2$ at cryogenic temperatures it has been shown that a peak near 1 $G{_0}$ identifies a single molecule Pt-H$_{2}$-Pt bridge. The histogram shows an additional structure with lower conductance that h

Nikolai M. Chtchelkatchev, Igor S. Burmistrov

We find the current voltage characteristics of a 2DEG-S interface in magnetic field taking into account the surface roughness. Typically in experiments $L/2R_c\gtrsim 3$, where $L$ is the surface length and $R_c$ is the cyclotron radius. The conductance behaves in experiments usually as $G=g_0+g_1\cos(2πν+δ_1)$; higher harmonics, $g_2\cos(4πν+δ_2),...$, are

G. Wuchterl, C. Broeg, S. Krause, B. Pecnik

We study the planet populations in the discovery window of the CoRoT-space-telescope scheduled for launch on December 27th. We base the prediction on `first principles&#39; calculations of planet formation in the framework of the planetesimal hypothesis. Aims: To provide a-priori planetary initial mass functions for confrontation with the CoRoT-planet discov

M. Virginia McSwain, Scott M. Ransom, Tabetha S. Boyajian, Erika D. Grundstrom

The production of runaway massive binaries offers key insights into the evolution of close binary stars and open clusters. The stars HD 14633 and HD 15137 are rare examples of such runaway systems, and in this work we investigate the mechanism by which they were ejected from their parent open cluster, NGC 654. We discuss observational characteristics that ca

M. Stejner

Both superbursters and soft X-ray transients probe the thermal structure of the crust on compact stars and are sensitive to the process of deep crustal heating. It was recently shown that the transfer of matter from crust to core in a strange star can heat the crust by deconfinement and ignite superbursts provided certain constraints on the strange quark mat

Y. T. Tanaka

The soft gamma repeater (SGR) 1900+14 emitted the giant flare on 27 August 1998. Most gamma-ray detectors saturated during the initial spike of the giant flare because of the intense flux. However the plasma particle detector onboard GEOTAIL observed the first 300 ms time profile with a time resolution of 5.577 ms and the initial spike of the giant flare was

Nicolao Fornengo

In this review article the current status of particle dark matter is addressed. We discuss the main theoretical extensions of the standard model which allow to explain dark matter in terms of a (yet undiscovered) elementary particle. We then discuss the theoretical predictions for the searches of particle dark matter: direct detection in low background under

W. Kundt

Almost 40 years after the discovery of pulsars -- and despite a plethora of secured data on them -- pulsar theory is still beset by a number of fundamental inconsistencies. In this short contribution, I will argue that (i) magnetars do not exist, (ii) (ordinary) pulsars turnoff (or &#39;die&#39;) when their wind pressure falls short of keeping the CSM at a s

Jes Madsen

The properties of strangelets are reviewed and two experiments searching for them in cosmic rays are described. The prospects for strangelets as ultra-high energy cosmic rays beyond the classical GZK-cutoff are discussed.

H. Grigorian, D. Blaschke, T. Klaehn

A new scheme for testing the nuclear matter (NM) equation of state (EoS) at high densities using constraints from compact star (CS) phenomenology is applied to neutron stars with a core of deconfined quark matter (QM). An acceptable EoS shall not to be in conflict with the mass measurement of 2.1 +/- 0.2 solar mass (1 sigma level) for PSR J0751+1807 and the

J. Petri

In this work we explore the idea that the high frequency QPOs observed in LMXBs may be explained as a resonant coupling between the neutron star spin and epicyclic modes of accretion disk oscillations. We propose a new model for these QPOs based on forced oscillations induced in the accretion disk due to a stellar asymmetric rotating gravitational or magneti

G. S. Bisnovatyi-Kogan

Many quasars and active galactic nuclei (AGN) appear in radio, optical, and X-ray maps, as a bright nuclear sources from which emerge single or double long, thin jets (Thomson et al., 1993). When observed with high angular resolution these jets show structure with bright knots separated by relatively dark regions. High percentages of polarization, sometimes

M. Massi

We discuss the &#34;basic&#34; condition for an accreting neutron star to become a microquasar, i.e. ejecting relativistic particles orthogonal to the accretion disk instead of confining disk-material down to the magnetic poles and creating the two emitting caps typical for a X-ray pulsar. Jet creation is prevented for B >/= 10^12 G independent of the accret

P. Hennebelle, E. Audit, M. -A Miville-Deschenes

{It is necessary to understand the dynamics of the atomic gas to use complex modeling and to carry out detailed comparisons between theoretical models and observations.}{In a companion paper, we present high resolution bidimensional numerical simulations of the interstellar atomic hydrogen. Here, we further characterize these simulations and we compare our r

P. Hennebelle, E. Audit

{We study in some details the statistical properties of the turbulent 2-phase interstellar atomic gas.{We present high resolution bidimensional numerical simulations of the interstellar atomic hydrogen which describe it over 3 to 4 orders of magnitude in spatial scales.}{The simulations produce naturally small scale structures having either large or small co

J. Schaffner-Bielich

The mass-radius relation of compact stars is discussed with relation to the presence of quark matter in the core. The existence of a new family of compact stars with quark matter besides white dwarfs and ordinary neutron stars is outlined.

I. Sagert, J. Schaffner-Bielich

The puzzling phenomenon of pulsar kicks, i.e. the observed large escape velocities of pulsars out of supernova remnants, is examined for compact stars with a strange quark matter core. The direct Urca process in quark matter is studied in the presence of a strong magnetic field. Conditions for an asymmetric emission of the produced neutrinos are worked out i

T. Multamaki, I. Vilja

Static spherically symmetric perfect fluid solutions are studied in metric $f(R)$ theories of gravity. We show that pressure and density do not uniquely determine $f(R)$ ie. given a matter distribution and an equation state, one cannot determine the functional form of $f(R)$. However, we also show that matching the outside Schwarzschild-de Sitter-metric to t

Julien Larena, Thomas Buchert, Jean-Michel Alimi

In the context of averaged cosmologies, the effective equations can be written in the form of &#34;regional&#34; Friedmannian equations with additional sources arising from the so-called backreaction of inhomogeneities. We propose a mean field description of this backreaction in terms of a regionally homogeneous scalar field: this provides a physical motivat

German Olivares, Diego Pavon, Fernando Atrio-Barandela

The coincidence problem of late cosmic acceleration gets significantly alleviated when a suitable interaction between matter and dark energy, either of phantom type or not, enters the picture. We show that a class of models featuring this interaction fares rather well when contrasted with the anisotropies of the CMBR and the matter power spectrum. The latter

M. Stupar, Q. A. Parker, M. D. Filipovic

New narrow-band HAlpha imaging and subsequent optical spectra confirm G315.1+2.7, a previously identified candidate supernova remnant (SNR), as a bona-fide Galactic SNR. Present observations are based on independent discovery of filamentary optical emission nebulosity on images of the AAO/UKST HAlpha survey of the southern Galactic plane which were found to

Vadim Adamyan, Sergey Tishchenko

Explicit expressions for the wave functions and dispersion equation for the band p - electrons in single-wall carbon nanotubes are obtained within the method of zero-range potentials. They are then used to investigate the absorption spectrum of polarized light caused by direct interband transitions in isolated nanotubes. It is shown that, at least, under the

CDF Collaboration

A search for a manifestly exotic S=-2 baryon state decaying to Xi- pi-, and its neutral partner decaying to Xi- pi+, has been performed using 220 pb^(-1) of pp= collisions at sqrt(s)=1.96 TeV collected by the Collider Detector at Fermilab. The Xi trajectories were measured in a silicon tracker before their decay, resulting in a sample with low background and

Chia-Fu Yu

We generalize the surjectivity result of the $p$-adic monodromy for the ordinary locus of a Siegel moduli space by Faltings and Chai (independently by Ekedahl) to that for any $p$-rank stratum. We discuss irreducibility and connectedness of some $p$-rank strata of the moduli spaces with parahoric level structure. Finer results are obtained on the Siegel 3-fo

Thomas Appelquist, Yang Bai, Maurizio Piai

We analyze the structure of a recently proposed effective field theory (EFT) for the generation of quark and lepton mass ratios and mixing angles, based on the spontaneous breaking of an SU(3) family gauge symmetry at a high scale F. We classify the Yukawa operators necessary to seed the masses, making use of the continuous global symmetries that they preser

Yoshiyasu Ishigami

We give a simple and natural (probabilistic) construction of hypergraph regularization. It is done just by taking a constant-bounded number of random vertex samplings only one time (thus, iteration-free). It is independent from the definition of quasi-randomness and yields a new elementary proof of a strong hypergraph regularity lemma. Consequently, as an ex

Lisa M. Young, Evan D. Skillman, Daniel R. Weisz, Andrew E. Dolphin

The Local Group galaxy Phoenix has the properties of a dwarf spheroidal galaxy, but an adjacent HI cloud has been found to be at the same radial velocity as the stars. The proximity suggests that this cloud is associated with the most recent ($\le 100$ Myr) star formation in Phoenix. We have obtained relatively high sensitivity and high resolution HI imaging

F. L. Semião, K. Furuya

The mode-mode entanglement between trapped ions and cavity fields is investigated in the dispersive regime. We show how a simple initial preparation of Gaussian coherent states and a postselection may be used to generate motional non-local mesoscopic states (NLMS) involving ions in different traps. We also present a study of the entanglement induced by dynam

Sergey Nikitin

The paper presents necessary and sufficient conditions for a nonlinear system to be stabilized by a feedback. The conditions are based on the ideas related to the well-known Pontryagin&#39;s maximum principle. That allows us to formulate the results in terms that are valid for continuous, discontinuous, stationary and time-dependent feedbacks.

Laurent Sanchez-Palencia, David Clément, Pierre Lugan, Philippe Bouyer

We show that the expansion of an initially confined interacting 1D Bose-Einstein condensate can exhibit Anderson localization in a weak random potential with correlation length σ_R. For speckle potentials the Fourier transform of the correlation function vanishes for momenta k > 2/σ_R so that the Lyapunov exponent vanishes in the Born approximation for k > 1

Christian Tanguy

The two-terminal reliability, known as the pair connectedness or connectivity function in percolation theory, may actually be expressed as a product of transfer matrices in which the probability of operation of each link and site is exactly taken into account. When link and site probabilities are $p$ and $ρ$, it obeys an asymptotic power-law behavior, for wh

F. J. Cao

The quantum dynamics of the symmetry broken λ(Φ^2)^2 scalar field theory in the presence of an homogeneous external field is investigated in the large N limit. We consider an initial thermal state of temperature T for a constant external field J. A subsequent sign flip of the external field, J to -J, gives rise to an out of equilibrium nonperturbative quantu

Viktor Margulis, Mikhail Pyataev

The electron transport in a four-terminal nanodevice consisting of two crossed nanotubes is investigated in the framework of the Landauer-Buttiker formalism. The evident formula for the ballistic conductance of the device is found using a model of crossed conductive cylinders with a point contact between them. Sharp conductance dips stipulated by resonance s

Elliot Leader, Aleksander V. Sidorov, Dimiter B. Stamenov

We have re-analyzed the world data on inclusive polarized DIS including the very precise CLAS proton and deuteron data, as well as the latest COMPASS data on the asymmetry $A_1^d$, and have studied the impact of these data on polarized parton densities and higher twist effects. We demonstrate that the low $Q^2$ CLAS data improve essentially our knowledge of

Indranil Chakrabarty, B. S. Choudhury

In this work we have introduced two party games with respective winning conditions. One cannot win these games deterministically in the classical world if they are not allowed to communicate at any stage of the game. Interestingly we find out that in quantum world, these winning conditions can be achieved if the players share an entangled state. We also intr

Marco Guzzi

This thesis work summarizes studies in QCD for applications both at hadron colliders and in exclusive processes. In the first part we focus our attention on the study of the initial state scaling violations and the evolution of the unpolarized parton distributions through Next-to-Next to Leading Order (NNLO) in $α_s$, the strong coupling, suitable for precis

Michael Uhlmann, Ralf Schützhold, Uwe R. Fischer

Motivated by a recent experiment, we study non-equilibrium quantum phenomena taking place in the quench of a spinor Bose-Einstein condensate through the zero-temperature phase transition separating the polar paramagnetic and planar ferromagnetic phases. We derive the typical spin domain structure (correlations of the effective magnetization) created by the q

Tianjun Li

The only allowed Higgs superpotential term at stringy tree level in the string derived Singlet Extensions of the Minimal Supersymmetric Standard Model (SEMSSM) is h S H_d H_u, which leads to an additional global U(1) symmetry in the Higgs potential. We propose the string inspired SEMSSM where the global U(1) symmetry is broken by the additional superpotentia

Adan Corcho, Carlos Matheus

We establish local and global well-posedness for the initial value problem associated to the one-dimensional Schrodinger-Debye (SD) system for data in the Sobolev spaces with low regularity. To obtain local results we prove two new sharp bilinear estimates for the coupling terms of this system in the continuous and periodic cases. Concerning global results,

Melanie Becker, Li-Sheng Tseng, Shing-Tung Yau

We characterize the geometric moduli of non-Kaehler manifolds with torsion. Heterotic supersymmetric flux compactifications require that the six-dimensional internal manifold be balanced, the gauge bundle be hermitian Yang-Mills, and also the anomaly cancellation be satisfied. We perform the linearized variation of these constraints to derive the defining eq

E. Minguzzi

It is shown that the warped product spacetime P=M *_f H, where H is a complete Riemannian manifold, and the original spacetime M share necessarily the same causality properties, the only exceptions being the properties of causal continuity and causal simplicity which present some subtleties. For instance, it is shown that if diamH=+\infty, the direct product

Steve Fisk

This work is divided into three parts. The first part concerns polynomials in one variable with all real roots. We consider linear transformations that preserve real rootedness, as well as matrices that preserve interlacing. The second part covers polynomials in several variables that generalize polynomials with all real roots. We introduce generating functi

K. S. Babu, R. N. Mohapatra, S. Nasri

We present a simple extension of MSSM which provides a unified picture of cosmological baryon asymmetry and dark matter. Our model introduces a gauge singlet field $N$ and a color triplet field $X$ which couple to the right--handed quark fields. The out--of equilibrium decay of the Majorana fermion $N$ mediated by the exchange of the scalar field $X$ generat

Yong-Geun Oh

This paper is withdrawn by the author due to a critical error in the proof of the main theorem, Theorem 3.10. (More specifically the identity (5.18) is incorrect in that the $T^*S^1(2)$-factor is missing in the right hand side of the equality.) Therefore the uniquenss question for $L^{(1,\infty)}$-case is still open.

I. A. Campbell, K. Hukushima, H. Takayama

A simple systematic rule, inspired by high-temperature series expansion (HTSE) results, is proposed for optimizing the expression for thermodynamic observables of ferromagnets exhibiting critical behavior at $\Tc$. This ``extended scaling&#39;&#39; scheme leads to a protocol for the choice of scaling variables, $τ=(T-\Tc)/T$ or $(T^2 - \Tc^2)/T^2$ depending

A. D. Smirnov

The contributions of the scalar leptoquark doublets into widths of the $K^0_L \to e^{\mp} μ^{\pm}$, $B^0 \to e^{\mp} τ^{\pm}$ decays are calculated in MQLS model with Higgs mechanism of the quark-lepton mass splitting. The resulted mass limits for the scalar leptoquarks are investigated in comparision with those for vector and chiral gauge leptoquarks. It is

Carlo Petronio, Andrei Vesnin

We consider closed orientable 3-dimensional hyperbolic manifolds which are cyclic branched coverings of the 3-sphere, with branching set being a two-bridge knot (or link). We establish two-sided linear bounds depending on the order of the covering for the Matveev complexity of the covering manifold. The lower estimate uses the hyperbolic volume and results o

Raazesh Sainudiin, Thomas York

In phylogenetic inference one is interested in obtaining samples from the posterior distribution over the tree space on the basis of some observed DNA sequence data. The challenge is to obtain samples from this target distribution without any knowledge of the normalizing constant. One of the simplest sampling methods is the rejection sampler due to von Neuma

Luca Amendola, Radouane Gannouji, David Polarski, Shinji Tsujikawa

We derive the conditions under which dark energy models whose Lagrangian densities f are written in terms of the Ricci scalar R are cosmologically viable. We show that the cosmological behavior of f(R) models can be understood by a geometrical approach consisting in studying the m(r) curve on the (r, m) plane, where m=Rf_{,RR}/f_{,R} and r=-Rf_{,R}/f with f_

Svante Janson, Malwina J. Luczak

We study the $k$-core of a random (multi)graph on $n$ vertices with a given degree sequence. In our previous paper [Random Structures Algorithms 30 (2007) 50--62] we used properties of empirical distributions of independent random variables to give a simple proof of the fact that the size of the giant $k$-core obeys a law of large numbers as ${n\to \infty}$.

Oren Bergman, Gilad Lifschytz

We analyze the resolution of the U(1)_A problem in the Sakai-Sugimoto holographic dual of large N_c QCD at finite temperature. It has been shown that in the confining phase the axial symmetry is broken at order 1/N_c, in agreement with the ideas of Witten and Veneziano. We show that in the deconfined phase the axial symmetry remains unbroken to all orders in

A. D. Mirlin, D. G. Polyakov, V. M. Vinokur

We consider the interplay of the elastic pinning and the Anderson localization in the transport properties of a charge-density wave in one dimension, within the framework of the Luttinger model in the limit of strong repulsion. We address a conceptually important issue of which of the two disorder-induced phenomena limits the mobility more effectively. We ar

Stephan Hell

Birch and Tverberg partitions are closely related concepts from discrete geometry. We show two properties for the number of Birch partitions: Evenness, and a lower bound. This implies the first non-trivial lower bound for the number of Tverberg partitions that holds for arbitrary q, where q is the number of partition blocks. The proofs are based on direct ar

R. Spurzem, M. Giersz, D. C. Heggie, D. N. C. Lin

At least 10-15% of nearby sun-like stars have known Jupiter-mass planets. In contrast, very few planets are found in mature open and globular clusters such as the Hyades and 47 Tuc. We explore here the possibility that this dichotomy is due to the post-formation disruption of planetary systems associated with the stellar encounters in long-lived clusters. On

Christian Nowak, Vakhtang G. Rostiashvili, Thomas A. Vilgis

A self-consistent field theory was developed in the grand-canonical ensemble formulation to study transitions in a helix-coil multiblock globule. Helical and coil parts are treated as stiff rods and self-avoiding walks of variable lengths correspondingly. The resulting field-theory takes, in addition to the conventional Zimm-Bragg (B.H. Zimm, I.K. Bragg, J.

Valmir C. Barbosa, Fernando M. L. Ferreira, Daniel V. Kling, Eduardo Lopes

In this work we deal with a mechanism for process simulation called a NonDeterministic Stochastic Activity Network (NDSAN). An NDSAN consists basically of a set of activities along with precedence relations involving these activities, which determine their order of execution. Activity durations are stochastic, given by continuous, nonnegative random variable

Kazuhiro Nakazawa, Kazuo Makishima, Yasushi Fukazawa

X-ray spectra of groups of galaxies, obtained with the GIS instrument onboard ASCA, were investigated for diffuse hard X-rays in excess of the soft thermal emission from their inter-galactic medium (IGM). In total, 18 objects with the IGM temperature of 0.7--1.7 keV were studied, including HCG 62 in particular. Non X-ray backgrounds in the GIS spectra were c

Sharanya Sur, Anvar Shukurov, Kandaswamy Subramanian

We present a simple semi-analytical model of nonlinear, mean-field galactic dynamos and use it to study the effects of various magnetic helicity fluxes. The dynamo equations are reduced using the `no-$z$&#39; approximation to a nonlinear system of ordinary differential equations in time; we demonstrate that the model reproduces accurately earlier results, in

Satoshi Iso, Takeshi Morita, Hiroshi Umetsu

A new method has been developed recently to derive Hawking radiations from black holes based on considerations of gravitational and gauge anomalies at the horizon gr-qc/0502074 hep-th/0602146. In this paper, we apply the method to Myers-Perry black holes with multiple angular momenta in various dimensions by using the dimensional reduction technique adopted

D. Gurevich, P. Pyatov, P. Saponov

Let R: V x V -> V x V be a Hecke type solution of the quantum Yang-Baxter equation (a Hecke symmetry). Then, the Hilbert-Poincre&#39; series of the associated R-exterior algebra of the space V is a ratio of two polynomials of degree m (numerator) and n (denominator). Assuming R to be skew-invertible, we define a rigid quasitensor category SW(V) of vector spa