September 2006 arXiv papers — page 45

T. Multamaki, J. Sainio, I. Vilja

The large-scale dynamics of a two-fluid system with a time dependent interaction is studied analytically and numerically. We show how a rapid transition can significantly suppress the large-scale curvature perturbation and present approximative formulae for estimating the effect. By comparing to numerical results, we study the applicability of the approximat

Kiki Vierdayanti, Shin Mineshige, Ken Ebisawa, Toshihiro Kawaguchi

An open question remains whether Ultraluminous X-ray Sources (ULXs) really contain intermediate-mass black holes (IMBHs). We carefully investigated the XMM-Newton EPIC spectra of the four ULXs that were claimed to be strong candidates of IMBHs by several authors. We first tried fitting by the standard spectral model of disk blackbody (DBB) + power-law (PL),

Piet Groeneboom, Marloes H. Maathuis, Jon A. Wellner

We study nonparametric estimation for current status data with competing risks. Our main interest is in the nonparametric maximum likelihood estimator (MLE), and for comparison we also consider a simpler ``naive estimator.'' Groeneboom, Maathuis and Wellner [Ann. Statist. (2008) 36 1031--1063] proved that both types of estimators converge globally an

Piet Groeneboom, Marloes H. Maathuis, Jon A. Wellner

We study nonparametric estimation of the sub-distribution functions for current status data with competing risks. Our main interest is in the nonparametric maximum likelihood estimator (MLE), and for comparison we also consider a simpler ``naive estimator.'' Both types of estimators were studied by Jewell, van der Laan and Henneman [Biometrika (2003)

Chen Cao, Hong Wu, Zhong Wang, Luis C. Ho

A large position angle misalignment between the stellar bar and the distribution of dust in the late-type barred spiral NGC 3488 was discovered, using mid-infrared images from the Spitzer Space Telescope and optical images from the Sloan Digital Sky Survey (SDSS). The angle between the bar and dust patterns was measured to be 25+-2deg, larger than most of th

J. De Loera, R. Hemmecke, S. Onn, U. G. Rothblum

We present a new algebraic algorithmic scheme to solve {\em convex integer maximization} problems of the following form, where $c$ is a convex function on $R^d$ and $w_1x,...,w_dx$ are linear forms on $R^n$, $$\max \{c(w_1 x,...,w_d x): Ax=b, x\in N^n\} .$$ This method works for arbitrary input data $A,b,d,w_1,...,w_d,c$. Moreover, for fixed $d$ and several

Vladimir Pascalutsa, Marc Vanderhaeghen, Shin Nan Yang

We review the description of the lowest-energy nucleon excitation -- the $Δ$(1232)-resonance. Much of the recent experimental effort has been focused on the precision measurements of the nucleon-to-$Δ$ transition by means of electromagnetic probes. We confront the results of these measuremnts with the state-of-the-art calculations based on chiral effective-f

Brian Forbes, Masao Jinzenji

We continue our study of equivariant local mirror symmetry of curves, i.e. mirror symmetry for X_k=O(k)+O(-2-k) over P^1 with torus action (lambda_1,lambda_2) on the bundle. For the antidiagonal action lambda_1=-lambda_2, we find closed formulas for the mirror map and a rational B model Yukawa coupling for all k. Moreover, we give a simple closed form for th

H. M. Chang, TEXONO Collaboration

A search of axions produced in nuclear transitions was performed at the Kuo-Sheng Nuclear Power Station with a high-purity germanium detector of mass 1.06 kg at a distance of 28 m from the 2.9 GW reactor core. The expected experimental signatures were mono-energetic lines produced by their Primakoff or Compton conversions at the detector. Based on 459.0/96.3

Tracy R. Slatyer, Raymond R. Volkas

We consider a brane generated by a scalar field domain wall configuration in 4+1 dimensions, interpolating, in most cases, between two vacua of the field. We study the cosmology of such a system in the cases where the effective four-dimensional brane metric is de Sitter or anti de Sitter, including a discussion of the bulk coordinate singularities present in

Xiaoping Zheng, Nana Pan, Shuhua Yang, Xuewen Liu

We derive the bulk viscous damping timescale of hybrid stars, neutron stars with quark matter core. The r-mode instability windows of the stars show that the theoretical results are consistent with the rapid rotation pulsar data, which may give an indication for the existence of quark matter in the interior of neutron stars. Hybrid stars instead of neutron o

Zhenxin Liu

Conley index theory is a very powerful tool in the study of dynamical systems, differential equations and bifurcation theory. In this paper, we make an attempt to generalize the Conley index to discrete random dynamical systems. And we mainly follow the Conley index for maps given by Franks and Richeson in [6]. Furthermore, we simply discuss the relations of

R. Winkler, U. Zülicke, Jens Bolte

In the Dirac theory for the motion of free relativistic electrons, highly oscillatory components appear in the time evolution of physical observables such as position, velocity, and spin angular momentum. This effect is known as zitterbewegung. We present a theoretical analysis of rather different Hamiltonians with gapped and/or spin-split energy spectrum (i

Stephen D. Bartlett, Terry Rudolph

We present a simple quantum many-body system - a two-dimensional lattice of qubits with a Hamiltonian composed of nearest-neighbor two-body interactions - such that the ground state is a universal resource for quantum computation using single-qubit measurements. This ground state approximates a cluster state that is encoded into a larger number of physical q

Suzanne M. Shontz, Stephen A. Vavasis

Compressible Mooney-Rivlin theory has been used to model hyperelastic solids, such as rubber and porous polymers, and more recently for the modeling of soft tissues for biomedical tissues, undergoing large elastic deformations. We propose a solution procedure for Lagrangian finite element discretization of a static nonlinear compressible Mooney-Rivlin hypere

Shao Ming Hu, G. Zhao, H. Y. Guo, X. Zhang

Many quasi-simultaneous optical observations of 17 blazars are obtained from previous papers published over the last 19 years in order to investigate the spectral slope variability and understand the radiation mechanism of blazars. The long-period dereddened optical spectral slopes are calculated. We analyse the average spectral slope distribution, which sug

Florian Marquardt, Benjamin Abel, Jan von Delft

We propose a measure for the "size" of a Schroedinger cat state, i.e. a quantum superposition of two many-body states with (supposedly) macroscopically distinct properties, by counting how many single-particle operations are needed to map one state onto the other. This definition gives sensible results for simple, analytically tractable cases and is

Peter P. Rohde

Quantum State Tomography (QST) of optical states is typically performed in the photon number degree of freedom, a procedure which is well understood and has been experimentally demonstrated. However, optical states have other degrees of freedom than just photon number, such as the spatial and temporal/spectral ones. Full characterization of photonic states r

Amaury Mouchet, Christopher Eltschka, Peter Schlagheck

Dynamical tunnelling between symmetry-related stable modes is studied in the periodically driven pendulum. We present strong evidence that the tunnelling process is governed by nonlinear resonances that manifest within the regular phase-space islands on which the stable modes are localized. By means of a quantitative numerical study of the corresponding Floq

Nicola Yanev, Rumen Andonov, Philippe Veber, Stefan Balev

This paper presents efficient algorithms for solving the problem of aligning a protein structure template to a query amino-acid sequence, known as protein threading problem. We consider the problem as a special case of graph matching problem. We give formal graph and integer programming models of the problem. After studying the properties of these models, we

A. L. Gonzalez, C. Noguez

The influence of morphology on the optical properties of silver nanoparticles is studied. A general relationship between the surface plasmon resonances and the morphology of each nanoparticle is established. The optical response is investigated for cubes and decahedrons with different truncations. We found that polyhedral nanoparticles composed with less fac

Paul S. Julienne, Bo Gao

Magnetically tunable scattering resonances have been used with great success for precise control of s-wave scattering lengths in ultracold atomic collisions. We describe relatively simple yet quite powerful analytic treatments of such resonances based on the analytic properties of the van der Waals long range potential. This theory can be used to characteriz

Lun-Shin Yao

The principle of multiple solutions of the Navier-Stokes equations discussed in this paper is not directed at any particular problems in fluid dynamics, nor at any specific applications. The non-uniqueness principle states that the Reynolds number, above its critical value, is insufficient to uniquely determine a flow field for a given geometry, or for simil

Fabio Pammolli, Dongfeng Fu, S. V. Buldyrev, Massimo Riccaboni

We introduce a model of proportional growth to explain the distribution $P(g)$ of business firm growth rates. The model predicts that $P(g)$ is Laplace in the central part and depicts an asymptotic power-law behavior in the tails with an exponent $ζ=3$. Because of data limitations, previous studies in this field have been focusing exclusively on the Laplace

M. Lebental, J. -S. Lauret, J. Zyss, C. Schmit

The far-field emission of two dimensional (2D) stadium-shaped dielectric cavities is investigated. Micro-lasers with such shape present a highly directional emission. We provide experimental evidence of the dependance of the emission directionality on the shape of the stadium, in good agreement with ray numerical simulations. We develop a simple geometrical

Thierry Faure, François Lusseyran, Luc Pastur, Romain Pethieu

A boundary layer interacting with a cavity is a benchmark case that is present in environmental applications, aeronautics, automobile aerodynamics or industrial applications, where the velocity over a rectangular cavity is relatively low. In the present investigation, the interaction between a laminar boundary layer with external velocity Ue and an open cavi

Gordon Chalmers

The speed of light is usually taken as one of the fundamental constants. String, and field, theories appear to require the altercation of this constant into a functional form $E(m,c)$ which is not $E=mc^2$. The analysis requires the re-interpretation of the renormalization group flow equations. There are quantum corrections to the mass-energy relation generi

Marzena Kozlowska, Ryszard Kutner

We analyse the dynamics of the Warsaw Stock Exchange index WIG at a daily time horizon before and after its well defined local maxima of the cusp-like shape decorated with oscillations. The rising and falling paths of the index peaks can be described by the Mittag-Leffler function superposed with various types of oscillations. The latter is a solution of our

F J Tapiador, R Verdejo

Ensemble forecasting is a technique devised to palliate sensitivity to initial conditions in nonlinear dynamical systems. The basic idea to avoid this sensitivity is to run the model many times under several slightly-different initial conditions, merging the resulting forecast in a combined product. We argue that this blending procedure is unphysical, and th

Jonathan J Hunt, Randall G Cameron, Martin A. K. Williams

A simulation methodology for predicting the time-course of enzymatic digestions is described. The model is based solely on the enzyme's subsite architecture and concomitant binding energies. This allows subsite binding energies to be used to predict the evolution of the relative amounts of different products during the digestion of arbitrary mixtures of

Edward Price, Noah Finkelstein

We present two programs that address needs to better prepare graduate students for their roles as professional physicists, particularly in the areas of teaching and education research. The two programs, Preparing Future Physicists (PFP) and a course, Teaching and Learning Physics, are designed to be mutually supportive, address these broader graduate roles,

Michael J. Barber, Manfred L. Ristig

Voltage-activated ion channels vary randomly between open and closed states, influenced by the membrane potential and other factors. Signal transduction is enhanced by noise in a simple ion channel model. The enhancement occurs in a finite range of signals; the range can be extended using populations of channels. The range increases more rapidly in multiple-

Yang Sun

Performing shell model calculations for heavy nuclei is a long-standing problem in nuclear physics. The shell model truncation in the configuration space is an unavoidable step. The Projected Shell Model (PSM) truncates the space under the guidance of the deformed mean-field solutions. This implies that the PSM uses a novel and efficient way to bridge the tw

N. Auerbach, V. Zelevinsky

A mechanism is considered for generating doorway states and intermediate structure in low-energy nuclear reactions as a result of collectivization of widths of unstable intrinsic states coupled to common decay channels. At the limit of strong continuum coupling, the segregation of broad (''super-radiating") and narrow (''trapped") sta

S. K. Bogner, R. J. Furnstahl, S. Ramanan, A. Schwenk

Nucleon-nucleon potentials evolved to low momentum, which show great promise in few- and many-body calculations, have generally been formulated with a sharp cutoff on relative momenta. However, a sharp cutoff has technical disadvantages and can cause convergence problems at the 10-100 keV level in the deuteron and triton. This motivates using smooth momentum

S. Karataglidis, K. Amos

The elastic electron scattering form factors, longitudinal and transverse, from the He and Li isotopes and from 8B have been studied. Large space shell model functions have been assumed. The precise distribution of the neutron excess has little effect on the form factors of the isotopes though there is a mass dependence in the charge densities. However, the

J. M. Arias, J. Dukelsky, J. E. Garcia-Ramos, J. Vidal

The phase diagram of two-level boson Hamiltonians, including the Interacting Boson Model (IBM), is studied beyond the standard mean field approximation using the Holstein-Primakoff mapping. The limitations of the usual intrinsic state (mean field) formalism concerning finite-size effects are pointed out. The analytic results are compared to numerics obtained

A. A. Vasenko, N. D. Galanina, K. E. Gusev, V. S. Demidov

The 28Si(p, p' gamma)24Mg reaction has been studied at the ITEP accelerator by the hadron-gamma coincidence method for a proton energy of 1 GeV. Two reaction products are detected: a 1368.6-keV gamma-ray photon accompanying the transition of the 24Mg* nucleus from the first excited state to the ground state and a proton p' whose momentum is measured

Milutin Stepić, Christian E. Rüter, Eugene Smirnov, Detlef Kip

We demonstrate numerically the existence of nonlinear Tamm oscillations at the interface between a substrate and one-dimensional waveguide array with both cubic and saturable, self-focusing and self-defocusing nonlinearity. Light is trapped in the vicinity of the boundary of the array due to the interplay between the repulsive edge potential and Bragg reflec

V. S. Gerdjikov, A. Kyuldjiev, G. Marmo, G. Vilasi

We report here the existence of Ermanno-Bernoulli type invariants for the Manev model dynamics which may be viewed upon as remnants of Laplace-Runge-Lenz vector whose conservation is characteristic of the Kepler model. If the orbits are bounded these invariants exist only when a certain rationality condition is met and thus we have superintegrability only on

Yu. N. Kosovtsov

Selection of 25 examples from extensive nontrivial families for different types of nonlinear PDEs and their formal general solutions are given. The main goal here is to show on examples the types of solvable PDEs and what their general solutions look like.

Jean Bricmont, Antti Kupiainen

We give a rigorous derivation of Fourier's law from a system of closure equations for a nonequilibrium stationary state of a Hamiltonian system of coupled oscillators subjected to heat baths on the boundary. The local heat flux is proportional to the temperature gradient with a temperature dependent heat conductivity and the stationary temperature exhibi

Eric Schmutz

Let M=M(n,q) be the average of the orders of the elements in the finite unitary group U(n,q). The asymptotic estimate log(M)=nlog(q)-log(n) +o(log n) is proved.

David Forge, Thomas Zaslavsky

Hyperplanes of the form x_j = x_i + c are called affinographic. For an affinographic hyperplane arrangement in R^n, such as the Shi arrangement, we study the function f(M) that counts integral points in [1,M]^n that do not lie in any hyperplane of the arrangement. We show that f(M) is a piecewise polynomial function of positive integers M, composed of terms

C. Villani

This memoir attempts at a systematic study of convergence to stationary state for certain classes of degenerate diffusive equations, by means of well-chosen Lyapunov functionals. Typical examples are the kinetic Fokker--Planck and Boltzmann equation. Many open problems and possible directions for future research are discussed.

Thomas Zaslavsky

Set-coloring a graph means giving each vertex a subset of a fixed color set so that no two adjacent subsets have the same cardinality. When the graph is complete one gets a new distribution problem with an interesting generating function. We explore examples and generalizations.

Thomas Zaslavsky

We generalize proper coloring of gain graphs to totally frustrated states, where each vertex takes a value in a set of `qualities' or `spins' that is permuted by the gain group. (An example is the Potts model.) The number of totally frustrated states satisfies the usual deletion-contraction law but is matroidal only for standard coloring, where the group act

David Forge, Thomas Zaslavsky

A topological hyperplane is a subspace of R^n (or a homeomorph of it) that is topologically equivalent to an ordinary straight hyperplane. An arrangement of topological hyperplanes in R^n is a finite set H such that k topological hyperplanes in H, if their intersection is nonempty, meet in a subspace that is a topological hyperplane in the intersection of an

Peter D. Hoff

Many multivariate data analysis techniques for an $m\times n$ matrix $\m Y$ are related to the model $\m Y = \m M +\m E$, where $\m Y$ is an $m\times n$ matrix of full rank and $\m M$ is an unobserved mean matrix of rank $K< (m\wedge n)$. Typically the rank of $\m M$ is estimated in a heuristic way and then the least-squares estimate of $\m M$ is obtained vi

Helge Glockner

Various definitions of C^k-maps on open subsets of finite-dimensional vector spaces over a complete valued field have been proposed in the literature. We show that the C^k-maps considered by Schikhof and De Smedt coincide with those of Bertram, Glockner and Neeb. By contrast, Ludkovsky&#39;s C^k-maps need not be C^k in the former sense, at least in positive

Anthony M. Bloch, Peter E. Crouch, Amit K. Sanyal

In their paper on discrete analogues of some classical systems such as the rigid body and the geodesic flow on an ellipsoid, Moser and Veselov introduced their analysis in the general context of flows on Stiefel manifolds. We consider here a general class of continuous time, quadratic cost, optimal control problems on Stiefel manifolds, which in the extreme

W. Jaworski, M. Neufang

Let $G$ be a locally compact group and $π$ a representation of $G$ by weakly^* continuous isometries acting in a dual Banach space $E$. Given a probability measure $μ$ on $G$ we study the Choquet-Deny equation $π(μ)x=x$, $x\in E$. We prove that the solutions of this equation form the range of a projection of norm 1 and can be represented by means of a ``Pois

G. L. Litvinov, G. B. Shpiz

In the framework of idempotent mathematics, analogs of the classical kernel theorems of L. Schwartz and A. Grothendieck are studied. Idempotent versions of nuclear spaces (in the sense of A. Grothendieck) are discussed. The so-called algebraic approach is used. This means that the basic concepts and results (including those of &#34;topological&#34; nature) a

I. Athanasopoulos, L. A. Caffarelli, S. Salsa

We study the regularity of the &#34;free surface&#34; in boundary obstacle problems. We show that near a non-degenerate point the free boundary is a $C^{1,α}$ $(n-2)$-dimensional surface in $\real^{n-1}$.

Didier Henrion

A new MATLAB package called HIFOO was recently proposed for H-infinity fixed-order controller design. This document illustrates how some standard controller design examples can be solved with this software.

Thierry Gallay, Mariana Haragus

The nonlinear Schroedinger equation has several families of quasi-periodic travelling waves, each of which can be parametrized up to symmetries by two real numbers: the period of the modulus of the wave profile, and the variation of its phase over a period (Floquet exponent). In the defocusing case, we show that these travelling waves are orbitally stable wi

Thierry Gallay, Mariana Haragus

The nonlinear Schroedinger equation possesses three distinct six-parameter families of complex-valued quasi-periodic travelling waves, one in the defocusing case and two in the focusing case. All these solutions have the property that their modulus is a periodic function of x-ct for some real c. In this paper we investigate the stability of the small amplitu

Andrew Comech

The caustics of Fourier integral operators are defined as caustics of the corresponding Schwartz kernels (Lagrangian distributions on $X\times Y$). The caustic set $Σ(C)$ of the canonical relation $C$ is characterized as the set of points where the rank of the projection $π:C\to X\times Y$ is smaller than its maximal value, $dim(X\times Y)-1$. We derive the

W. N. Everitt

This survey paper reports on the properties of the fourth-order Bessel-type linear ordinary differential equation, on the generated self-adjoint differential operators in two associated Hilbert function spaces, and on the generalisation of the classical Hankel integral transform. These results are based upon the properties of the classical Bessel and Laguerr

Marc Chardin, Amadou Lamine Fall, Uwe Nagel

We establish bounds for the Castelnuovo-Mumford regularity of a finitely generated graded module and its symmetric powers in terms of the degrees of the generators of the module and the degrees of their relations. We extend to modules (and improve) the known bounds for homogenous ideal in a polynomial ring established by Galligo, Guisti, Caviglia and Sbarra.

D. Huybrechts

Survey written for the Proceedings of the AMS Meeting on Algebraic Geometry, Seattle, 2005. Based on the talk delivered at this occasion, but a few comments on recent developments are added.

Hasan Akin

In this paper we study the measure-theoretical entropy of the one-dimensional linear cellular automata (CA hereafter) $T_{f[-l,r]}$, generated by local rule $f(x_{-l},...,x_{r})= \sum\limits_{i=-l}^{r}λ_{i}x_{i}(\text{mod}\ m)$, where $l$ and $r$ are positive integers, acting on the space of all doubly infinite sequences with values in a finite ring $\mathbb

Kevin Purbhoo

We examine certain maps from root systems to vector spaces over finite fields. By choosing appropriate bases, the images of these maps can turn out to have nice combinatorial properties, which reflect the structure of the underlying root system. The main examples are E_6 and E_7.

Sergei Chmutov, Igor Pak

We show that the Kauffman bracket $[L]$ of a checkerboard colorable virtual link $L$ is an evaluation of the Bollobás-Riordan polynomial $R_{G_L}$ of a ribbon graph associated with $L$. This result generalizes Thistlethwaite&#39;s celebrated theorem relating the Kauffman bracket with the Tutte polynomial of planar graphs.

Andrew Comech, Scipio Cuccagna, Dmitry Pelinovsky

We prove the instability of a ``critical&#39;&#39; solitary wave of the generalized Korteweg -- de Vries equation, the one with the speed at the border between the stability and instability regions. The instability mechanism involved is ``purely nonlinear&#39;&#39;, in the sense that the linearization at a critical soliton does not have eigenvalues with posi

Cristian Lenart, Alexander Postnikov

We present a simple combinatorial model for the characters of the irreducible integrable highest weight modules for complex symmetrizable Kac-Moody algebras. This model can be viewed as a discrete counterpart to the Littelmann path model. We describe crystal graphs and give a Littlewood-Richardson rule for decomposing tensor products of irreducible represent

Andreas Brandhuber, Gabriele Travaglini

Over the past two years, the use of on-shell techniques has deepened our understanding of the S-matrix of gauge theories and led to the calculation of many new scattering amplitudes. In these notes we review a particular on-shell method developed recently, the quantum MHV diagrams, and discuss applications to one-loop amplitudes. Furthermore, we briefly disc

Daniel Arean, Alfonso V. Ramallo, Diego Rodriguez-Gomez

We consider the defect theory obtained by intersecting D3- and D5-branes along two common spatial directions. We work in the approximation in which the D5-brane is a probe in the AdS_5xS^5 background. By adding worldvolume flux to the D5-brane and choosing an appropriate embedding of the probe in AdS_5xS^5, one gets a supersymmetric configuration in which so

Christian S. Fischer, Jan M. Pawlowski

We uniquely determine the infrared asymptotics of Green functions in Landau gauge Yang-Mills theory. They have to satisfy both, Dyson-Schwinger equations and functional renormalisation group equations. Then, consistency fixes the relation between the infrared power laws of these Green functions. We discuss consequences for the interpretation of recent result

S. Villalba-Chávez, H. Pérez-Rojas

Due to its interaction with the virtual electron-positron field in vacuum, the photon exhibits a nonzero anomalous magnetic moment whenever it has a nonzero transverse momentum component to an external constant magnetic field. At low and high frequencies this anomalous magnetic moment behaves as paramagnetic, and at energies near the first threshold of pair

Nathan Berkovits

The non-minimal pure spinor formalism for the superstring is used to prove two new multiloop theorems which are related to recent higher-derivative $R^4$ conjectures of Green, Russo and Vanhove. The first theorem states that when $0<n<12$, $\partial^n R^4$ terms in the Type II effective action do not receive perturbative contributions above $n/2$ loops. The

David Bailin, Alex Love

We construct N=1 supersymmetric fractional branes on the Z_6&#39; orientifold. Intersecting stacks of such branes are needed to build a supersymmetric standard model. If $a,b$ are the stacks that generate the SU(3)_c and SU(2)_L gauge particles, then, in order to obtain just the chiral spectrum of the (supersymmetric) standard model (with non-zero Yukawa cou

Barak Kol

This paper describes and proves a canonical procedure to decouple perturbations and optimize their gauge around backgrounds with one non-homogeneous dimension, namely of co-homogeneity 1, while preserving locality in this dimension. Derivatively-gauged fields are shown to have a purely algebraic action; they can be decoupled from the other fields through gau

Jared Kaplan, Philip C. Schuster, Natalia Toro

Many proposed solutions to the hierarchy problem rely on dimensional transmutation in asymptotically free gauge theories, and these theories often have dual descriptions in terms of a warped extra dimension. Gravitational calculations show that the confining phase transition in Randall-Sundrum models is first-order and parametrically slower than the rate exp

Olga Mena, Hiroshi Nunokawa, Stephen Parke

The determination of the ordering of the neutrino masses (the hierarchy) is probably a crucial prerequisite to understand the origin of lepton masses and mixings and to establish their relationship to the analogous properties in the quark sector. Here, we follow an alternative strategy to the usual neutrino--antineutrino comparison in long baseline neutrino

B. Borasoy, Ulf-G. Meißner, R. Nißler

The claim that the light quark mass ratio (m_d - m_u)/m_s can be extracted from the decay width ratio Gamma(eta&#39; -> pi^0 pi^+ pi^-)/Gamma(eta&#39; -> eta pi^+ pi^-) is critically investigated within a U(3) chiral unitary framework. The influence of the recent VES data on the eta&#39; -> eta pi^+ pi^- decay is also discussed.

L. Y. Xiao, H. Q. Zheng, Z. Y. Zhou

We review the spectrum of lightest scalar resonances recently determined using dispersion techniques. The conceptual difference between the pole mass and the bare mass (or the line--shape mass) is stressed. The nature of the lightest scalars are discussed and we argue, without relying on any model details, that the $σ(500)$, $κ(700)$, $a_0(980)$ and $f_0(980

Yue-Liang Wu, Yu-Feng Zhou, Ci Zhuang

Based on the latest experimental data of $B \to ππ$ and $πK$ modes, a model-independent analytical analysis is presented. The CP-averaged branching ratio difference $ΔR = R_c - R_n$ in $B\to πK$ decays with $R_c = 2Br(π^0K^-)/Br(π^-\bar{K}^0)$ and $R_n =Br(π^+K^-)/2Br(π^0\bar{K}^0)$ is reduced though it remains larger than the prediction from the standard mo

J. J. Sanz-Cillero

The semileptonic B-> Xu l nu decays allow a pretty clean determination of the CKM matrix element |Vub|. Nevertheless, the presence of weak-annihilation effects near the end-point of the q2 spectrum introduces uncertainties in the inclusive calculation, requiring the use of non-perturbative techniques like heavy meson chiral perturbation theory and large NC l

A. Hart, G. M. von Hippel, R. R. Horgan

We construct the S-wave part of the electromagnetic vector annihilation current to $O(α_s v^2)$, where $v$ is the non-relativistic quark velocity, for heavy quarks whose dynamics are described by the NRQCD action on the lattice. The NRQCD vector current for $Q\bar{Q}$ annihilation is expressed as a linear combination of lattice operators with quantum numbers

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

The QCDSF/UKQCD collaboration has an ongoing program to calculate nucleon matrix elements with two flavours of dynamical O(a) improved Wilson fermions. Here we present recent results on the electromagnetic form factors, the quark momentum fraction <x> and the first three moments of the nucleon&#39;s spin-averaged and spin-dependent generalised parton distrib

A. Brotas

The coordinate system $(\bar{x},\bar{t})$ defined by $r = 2m + K\bar{x}- c K \bar{t}$ and $t=\bar{x}/cK - 1 /cK \int_{r_a}^r (1- 2m/r + K^2)^{1/2} (1 - 2m/r)^{-1}dr$ allow us to write the Schwarzschild metric in the form: \[ds^2=c^2 d\bar{t}^2 + (W^2/K^2 - 2W/K) d\bar{x}^2 + 2c (1 + W/K) d\bar{x}d\bar{t} - r^2 (dθ^2 + cos^2θdϕ^2)\] with $W=(1 - 2m/r + K^2)^{

Shai Carmi, Zhenhua Wu, Eduardo López, Shlomo Havlin

We study the transport properties of model networks such as scale-free and Erdős-Rényi networks as well as a real network. We consider the conductance $G$ between two arbitrarily chosen nodes where each link has the same unit resistance. Our theoretical analysis for scale-free networks predicts a broad range of values of $G$, with a power-law tail distributi

M. Angeles Serrano, Marian Boguna, Romualdo Pastor-Satorras

We develop a statistical theory to characterize correlations in weighted networks. We define the appropriate metrics quantifying correlations and show that strictly uncorrelated weighted networks do not exist due to the presence of structural constraints. We also introduce an algorithm for generating maximally random weighted networks with arbitrary $P(k,s)$

S. Y. Zhou, G. -H. Gweon, A. Lanzara

In this paper, we present a high resolution angle resolved photoemission spectroscopy (ARPES) study of the electronic properties of graphite. We found that the nature of the low energy excitations in graphite is particularly sensitive to interlayer coupling as well as lattice disorder. As a consequence of the interlayer coupling, we observed for the first ti

Klaus Michael Indlekofer, Joachim Knoch, Joerg Appenzeller

We employ a novel multi-configurational self-consistent Green&#39;s function approach (MCSCG) for the simulation of nanoscale Schottky-barrier field-effect transistors. This approach allows to calculate the electronic transport with a seamless transition from the single-electron regime to room temperature field-effect transistor operation. The particular imp

O. Prokhnenko, R. Feyerherm, E. Dudzik, S. Landsgesell

Neutron powder diffraction and single crystal x-ray resonant magnetic scattering measurements suggest that Dy plays an active role in enhancing the ferroelectric polarization in multiferroic DyMnO3 above TNDy = 6.5 K. We observe the evolution of an incommensurate ordering of Dy moments with the same periodicity as the Mn spiral ordering. It closely tracks th

J. F. Scott

Early work by the author with Prof. Ishibashi [Scott et al., J. Appl. Phys. 64, 787 (1988)] showed that switching kinetics in ferroelectrics satisfy a constraint on current transients compatible with d = 2.5 dimensionality. At that time with no direct observations of the domains, it was not possible to conclude whether this was a true Hausdorff dimension or

S. V. Demishev, A. V. Semeno, H. Ohta, S. Okubo

Anomalous polarization characteristics of magnetic resonance in CuGeO3 doped with 2% of Co impurity are reported. For the Faraday geometry this mode is damped for the microwave field Bw aligned along a certain crystallographic direction showing that the character of magnetic oscillation differs from the standard spin precession. The observed resonance coexis

J. Sichelschmidt, J. Wykhoff, H. -A. Krug von Nidda, J. Ferstl

Below the Kondo temperature $T_{\rm K}$ electron spin resonance (ESR) usually is not observable from the Kondo-ion itself because the characteristic spin fluctuation energy results in a huge width of the ESR line. The heavy fermion metal YbRh$_{2}$Si$_{2}$ seems to be an exceptional case where definite ESR spectra show characteristic properties of the Kondo-

Matej Praprotnik, Kurt Kremer, Luigi Delle Site

For the study of complex synthetic and biological molecular systems by computer simulations one is still restricted to simple model systems or to by far too small time scales. To overcome this problem multiscale techniques are being developed for many applications. However in almost all cases, the regions of different resolution are fixed and not in a true e

J. M. Brader, T. Voigtmann, M. E. Cates, M. Fuchs

We consider the nonlinear rheology of dense colloidal suspensions under a time-dependent simple shear flow. Starting from the Smoluchowski equation for interacting Brownian particles advected by shearing (ignoring fluctuations in fluid velocity) we develop a formalism which enables the calculation of time-dependent, far-from-equilibrium averages. Taking shea

Eeuwe S. Zijlstra, Larisa L. Tatarinova, Martin E. Garcia

Using first principles, all-electron calculations and dynamical simulations we study the behavior of the A_1g and E_g coherent phonons induced in Bi by intense laser pulses. We determine the potential landscapes in the laser heated material and show that they exhibit phonon-softening, phonon-phonon coupling, and anharmonicities. As a consequence the E_g mode

B. V. Hall, S. Whitlock, R. Anderson, P. Hannaford

We report on the adiabatic splitting of a BEC of $^{87}$Rb atoms by an asymmetric double-well potential located above the edge of a perpendicularly magnetized TbGdFeCo film atom chip. By controlling the barrier height and double-well asymmetry the sensitivity of the axial splitting process is investigated through observation of the fractional atom distributi

M. H. Ernst, E. Trizac, A. Barrat

Within the framework of the homogeneous non-linear Boltzmann equation, we present a new analytic method, without the intrinsic limitations of existing methods, for obtaining asymptotic solutions. This method permits extension of existing results for Maxwell molecules and hard spheres to large classes of particle interactions, from very hard spheres to softer

O. Tsyplyatyev, O. Kashuba, V. I. Fal&#39;ko

We show that a thermally excited spin-current naturally appears in metals with embedded ferromagnetic nanoclusters. When such materials are subjected to a magnetic field, a spin current can be generated by a temperature gradient across the sample as a signature of electron-hole symmetry breaking in a metal due to the electron spin-flip scattering from polari

K. De, S. Majumdar, S. Giri

We observe an interesting scenario of field induced metastabilities in the resistivity measurements. The resistivity exhibits a bifurcation of zero-field cooled and field-cooled (FC) temperature dependence below the paramagnetic to ferromagnetic transition ($T_c$). The clear evidence of {\it inverse} thermal hysteresis of resistivity is observed under FC con

A. Sparavigna, A. Mello, B. Montrucchio

The 4,n-alkyloxybenzoic acid 6OBAC has a very rich variety of crystalline structures and two nematic sub-phases, characterised by different textures. It is a material belonging to a family of liquid crystals formed by hydrogen bonded molecules, the 4,n-alkyloxybenzoic acids indicates the homologue number). The homologues with n ranging from 7 to 13 display b

T. C. Li, Shao-Ping Lu

The conductance of metallic graphene nanoribbons (GNRs) with single defects and weak disorder at their edges is investigated in a tight-binding model. We find that a single edge defect will induce quasi-localized states and consequently cause zero-conductance dips. The center energies and breadths of such dips are strongly dependent on the geometry of GNRs.

A. Sparavigna, A. Mello, B. Montrucchio

Recently we have observed in compounds of the 4,n-alkyloxybenzoic acid series, with the homologous index n ranging from 6 to 9, a texture transition in the nematic range which subdivides the nematic phase in two sub-phases displaying different textures in polarised light analysis. To investigate a persistence of texture transitions in nematic phases, we prep