July 2006 arXiv papers — page 2

M. Bender, P. Bonche, P. -H. Heenen

We discuss shape coexistence in the neutron-deficient Kr72-Kr78 isotopes in the framework of configuration mixing calculations of particle-number and angular-momentum projected axial mean-field states obtained from self-consistent calculations with the Skyrme interaction SLy6 and a density-dependent pairing interaction. While our calculation reproduces quali

Shakeb Ahmad, M. Sajjad Athar, S. K. Singh

The charged current one pion production induced by $ν_μ$ from nucleons and nuclei like $^{12}$C and $^{16}$O nuclei has been studied. The calculations have been done for the incoherent and the coherent processes from nuclear targets assuming the $Δ$ dominance model and take into account the effect of Pauli blocking, Fermi motion of the nucleon and renormaliz

K. Sasaki, E. Oset, M. J. Vicente Vacas

We study the central part of Lambda N and Lambda Lambda potential by considering the correlated and uncorrelated two-meson exchange besides the omega exchange contribution. The correlated two-meson is evaluated in a chiral unitary approach. We find that a short range repulsion is generated by the correlated two-meson potential which also produces an attracti

STAR Collaboration, B. Abelev

We present strange particle spectra and yields measured at mid-rapidity in $\sqrt{\text{s}}=200$ GeV proton-proton ($p+p$) collisions at RHIC. We find that the previously observed universal transverse mass ($\mathrm{m_{T}}\equiv\sqrt{\mathrm{p_{T}}^{2}+\mathrm{m}^{2}}$) scaling of hadron production in $p+p$ collisions seems to break down at higher \mt and th

D. Y Stewart, P. F. Harrison, B. Morgan, Y. A. Ramachers

The design task of creating an efficient radiation shield for the new COBRA double-beta decay experiment led to a comprehensive study of commercially available shielding materials. The aim was to find the most efficient combination of materials under the constraints of an extreme low-background experiment operating in a typical underground laboratory. All ex

Jean-Luc Thiffeault, Khalid Kamhawi

We consider steady gravity-driven flow of a thin layer of viscous fluid over a curved substrate. The substrate has topographical variations (`bumps') on a large scale compared to the layer thickness. Using lubrication theory, we find the velocity field in generalized curvilinear coordinates. We correct the velocity field so as to satisfy kinematic constr

U. E. Vincent, A. Kenfack

We study the bifurcations and the chaotic behaviour of a periodically forced double-well Duffing oscillator coupled to a single-well Duffing oscillator. Using the amplitude and the frequency of the driving force as control parameters, we show that our model presents phenomena which were not observed in coupled periodically forced Duffing oscillators with ide

Guido Ciraolo, Cristel Chandre, Ricardo Lima, Marco Pettini

In this article we present an application of a method of control of Hamiltonian systems to the chaotic velocity diffusion of a cold electron beam interacting with electrostatic waves. We numerically show the efficiency and robustness of the additional small control term in restoring kinetic coherence of the injected electron beam.

Hidetsugu Sakaguchi, Tomoko Higashiuchi

Two-dimensional gray solitons to the nonlinear Schroedinger equation are numerically created by two processes to show its robustness. One is transverse instability of a one-dimensional gray soliton, and another is a pair annihilation of a vortex and an antivortex. The two-dimensional dark solitons are anisotropic and propagate in a certain direction. The two

Dmitry K. Demskoi, Vladimir V. Sokolov

New quasilocal recursion and Hamiltonian operators for the Krichever-Novikov and the Landau-Lifshitz equations are found. It is shown that the associative algebra of quasilocal recursion operators for these models is generated by a couple of operators related by an elliptic curve equation. A theoretical explanation of this fact for the Landau-Lifshitz equati

Rowan Killip, Mihai Stoiciu

We study CMV matrices (a discrete one-dimensional Dirac-type operator) with random decaying coefficients. Under mild assumptions we identify the local eigenvalue statistics in the natural scaling limit. For rapidly decreasing coefficients, the eigenvalues have rigid spacing (like the numerals on a clock); in the case of slow decrease, the eigenvalues are dis

Marcin Jankiewicz, Thomas W. Kephart

We show interesting relations between extremal partition functions of a family of conformal field theories and dimensions of the irreducible representations of the Fischer-Griess Monster sporadic group. We argue that these relations can be interpreted as an extension of Monster moonshine.

Pavel Etingof, Igor Pak

We present a new algebraic extension of the classical MacMahon Master Theorem. The basis of our extension is the Koszul duality for non-quadratic algebras defined by Berger. Combinatorial implications are also discussed.

Yitwah Cheung, Alex Eskin

This preliminary report contains a sketch of the proof of the following result: a slowly divergent Teichmuller geodesic satisfying a certain logarithmic law is determined by a uniquely ergodic measured foliation.

Yitwah Cheung

In this paper we compute the Hausdorff dimension of the set D_n of points on divergent trajectories of the homogeneous flow induced by a certain one-parameter subgroup of G=SL(2,R) acting by left multiplication on the product space G^n/Gamma^n, where Gamma=SL(2,Z). We prove that the Hausdorff dimension of D_n equals 3n-(1/2) for any n greater than one.

Yi Hu

We show that the moduli space of stable n-pointed rational curves can be flatly degenerated to a projective toric variety. We arrive at this by showing that the Chow quotients of the Grassmannians admit toric degenerations, which in turn, follows from a theorem that we prove for toric degenerations of more general Chow quotients. Along the way, we also argue

Charles F. Dunkl

There is a commutative algebra of differential-difference operators, acting on polynomials on R_2, associated with the reflection group B2. This paper presents an integral transform which intertwines this algebra, allowing one free parameter, with the algebra of partial derivatives. The method of proof depends on properties of a certain class of balanced ter

B. Clarke, Ao Yuan

Sample size criteria are often expressed in terms of the concentration of the posterior density, as controlled by some sort of error bound. Since this is done pre-experimentally, one can regard the posterior density as a function of the data. Thus, when a sample size criterion is formalized in terms of a functional of the posterior, its value is a random var

Manfred Einsiedler, Elon Lindenstrauss, Philippe Michel, Akshay Venkatesh

We prove results towards the equidistribution of certain families of periodic torus orbits on homogeneous spaces, with particular focus on the case of the diagonal torus acting on quotients of $\PGL_n(\R)$. After attaching to each periodic orbit an integral invariant (the discriminant) our results have the following flavour: certain standard conjectures abou

Pavel Kargaev, Evgeny Korotyaev

We study the properties of a conformal mapping $z(k)$ from the plane without vertical slits $\G_n=[u_n-ih_n, u_n+ih_n], n\in\Z$ and $h=(h_n)_{n\in\Z}\in \ell^2$, onto the complex plane without horizontal slits $\g_nß\R, n\in\Z$, with the asymptotics $z(iv)=iv+ o(1), v\to\iy$. Here $u_{n+1}-u_n\ge 1, n\in \Z$. Introduce the sequences $l=(|\g_n|)_{n\in\Z}$. %

Dmitry Chelkak, Evgeny Korotyaev

We consider the perturbed harmonic oscillator $T_Dψ=-ψ''+x^2ψ+q(x)ψ$, $ψ(0)=0$, in $L^2(\R_+)$, where $q\in\bH_+=\{q', xq\in L^2(\R_+)\}$ is a real-valued potential. We prove that the mapping $q\mapsto{\rm spectral data}={\rm \{eigenvalues of\}T_D{\rm \}}\oplus{\rm \{norming constants\}}$ is one-to-one and onto. The complete characterization of t

Laurent Bordes, Stéphane Mottelet, Pierre Vandekerkhove

Suppose that univariate data are drawn from a mixture of two distributions that are equal up to a shift parameter. Such a model is known to be nonidentifiable from a nonparametric viewpoint. However, if we assume that the unknown mixed distribution is symmetric, we obtain the identifiability of this model, which is then defined by four unknown parameters: th

Dmitri Chelkak, Evgeny Korotyaev

Consider the operator $H\p=-\p''+q\p=ł\p$, $\p(0)=0$, $\p'(1)+b\p(1)=0$ acting in $L^2(0,1)$, where $q\in L^2(0,1)$ is a real potential. Let $ł_n(q,b)$, $n\ge 0$, be the eigenvalues of $H$ and $\n_n(q,b)$ be the so-called norming constants. We give a complete characterization of all spectral data $(\{ł_n\}_0^\iy;\{\n_n\}_0^\iy)$ that correspond t

Dmitry Chelkak, Evgeny Korotyaev

We obtain a parametrization of the isospectral set of matrix-valued potentials for the vector-valued Sturm-Liouville problem on a finite interval.

Jochen Brüning, Dmitry Chelkak, Evgeny Korotyaev

Consider the Jacobi operators $\cJ$ given by $(\cJ y)_n=a_ny_{n+1}+b_ny_n+a_{n-1}^*y_{n-1}$, $y_n\in \C^m$ (here $y_0=y_{p+1}=0$), where $b_n=b_n^*$ and $a_n:\det a_n\ne 0$ are the sequences of $m\ts m$ matrices, $n=1,..,p$. We study two cases: (i) $a_n=a_n^*>0$; (ii) $a_n$ is a lower triangular matrix with real positive entries on the diagonal (the matrix $

Ilya Tyomkin

In the current paper we prove that any Severi variety on a Hirzebruch surface contains a unique component parameterizing irreducible nodal curves of the given genus in characteristic zero.

Antoine Chambaz

This paper deals with order identification for nested models in the i.i.d. framework. We study the asymptotic efficiency of two generalized likelihood ratio tests of the order. They are based on two estimators which are proved to be strongly consistent. A version of Stein's lemma yields an optimal underestimation error exponent. The lemma also implies th

V. Uma

The {\it torus manifolds} have been defined and studied by M. Masuda and T. Panov (arXiv:math.AT/0306100) who in particular describe its cohomology ring structure. In this note we shall describe the topological $K$-ring of a class of torus manifolds (those for which the orbit space under the action of the compact torus is a {\it homology polytope} whose {\it

István Berkes, Lajos Horváth, Piotr Kokoszka, Qi-Man Shao

We develop a testing procedure for distinguishing between a long-range dependent time series and a weakly dependent time series with change-points in the mean. In the simplest case, under the null hypothesis the time series is weakly dependent with one change in mean at an unknown point, and under the alternative it is long-range dependent. We compute the CU

Benoit Perthame, Luis Vega

We consider the Helmholtz equation with a variable index of refraction $n(x)$, which is not necessarily constant at infinity but can have an angular dependency like $n(x)\to n\_\infty(x/|x |)$ as $|x |\to \infty$. Under some appropriate assumptions on this convergence and on $n\_\infty$ we prove that the Sommerfeld condition at infinity still holds true unde

Rainer Dahlhaus, Suhasini Subba Rao

In this paper the class of ARCH$(\infty)$ models is generalized to the nonstationary class of ARCH$(\infty)$ models with time-varying coefficients. For fixed time points, a stationary approximation is given leading to the notation ``locally stationary ARCH$(\infty)$ process.'' The asymptotic properties of weighted quasi-likelihood estimators of time-

Peter M. Robinson, Paolo Zaffaroni

Strong consistency and asymptotic normality of the Gaussian pseudo-maximum likelihood estimate of the parameters in a wide class of ARCH$(\infty)$ processes are established. The conditions are shown to hold in case of exponential and hyperbolic decay in the ARCH weights, though in the latter case a faster decay rate is required for the central limit theorem

Alina Vdovina

We compute an exact formula for the order of the class of the identity in the K_0 group of an infinite class of two-dimensional Kuntz-Crieger algebras.

Robert Parviainen

We count the number of occurrences of restricted patterns of length 3 in permutations with respect to length and the number of cycles. The main tool is a bijection between permutations in standard cycle form and weighted Motzkin paths.

Taekyun Kim

In the recent p-adic q-integral on the p-adic integers' rings was constructed >. The purpose of this paper is to give several interesting integral equation for the p-adic q-integerals on the rings of p-adic integers. As an integral equations, we will treat relations between p-adic q-integral's equations and q-Bernoulli and Euler numbers.

Linfan Mao, Yanpei Liu

A map is a connected topological graph $Γ$ cellularly embedded in a surface. In this paper, applying Tutte's algebraic representation of map, new ideas for enumerating non-equivalent orientable or non-orientable maps of graph are presented. By determining automorphisms of maps of Cayley graph $Γ={\rm Cay}(G:S)$ with ${\rm Aut} Γ\cong G\times H$ on locall

Linfan Mao, Yanpei Liu, Feng Tian

A map is a connected topological graph cellularly embedded in a surface and a complete map is a cellularly embedded complete graph in a surface. In this paper, all automorphisms of complete maps of order n are determined by permutations on its vertices. Applying a scheme for enumerating maps on surfaces with a given underlying graph, the numbers of unrooted

J. -F. Lafont, B. Schmidt

We study compact Riemannian manifolds for which the light between any pair of points is blocked by finitely many point shades. Compact flat Riemannian manifolds are known to have this finite blocking property. We conjecture that amongst compact Riemannian manifolds this finite blocking property characterizes the flat metrics. Using entropy considerations, we

J. Cislo, M. Wolf

We investigate the relation between the Riesz and the Baez-Duarte criterion for the Riemann Hypothesis. In particular we present the relation between the function $R(x)$ appearing in the Riesz criterion and the sequence $c_k$ appearing in the Baez-Duarte formulation. It is shown that $R(x)$ can expressed by $c_k$ and vice versa the sequence $c_k$ can be obta

Frank Schuhmacher

We prove explit formulas for the decomposition of a differential graded Lie algebra into a minimal and a linear $L_\infty$-algebra. We define a category of metric $L_\infty$-algebras, called Palamodov $L_\infty$ algebras, where the structure maps satisfy a certain convergence condition and deduce a decomposition theorem for differential graded Lie algebras i

John Loftin, Mao-Pei Tsui

We construct noncompact solutions to the affine normal flow of hypersurfaces, and show that all ancient solutions must be either ellipsoids (shrinking solitons) or paraboloids (translating solitons). We also provide a new proof of the existence of a hyperbolic affine sphere asymptotic to the boundary of a convex cone containing no lines, which is originally

A. Yu. Olshanskii, D. V. Osin

We first give a short group theoretic proof of the following result of Lackenby. If $G$ is a large group, $H$ is a finite index subgroup of $G$ admitting an epimorphism onto a non--cyclic free group, and $g$ is an element of $H$, then the quotient of $G$ by the normal subgroup generated by $g^n$ is large for all but finitely many $n\in \mathbb Z$. In the sec

Murray Elder

We prove that the set of permutations generated by a stack of depth two and an infinite stack in series has a basis (defining set of forbidden patterns) consisting of 20 permutations of length 5, 6, 7 and 8. We prove this via a ``canonical'' generating algorithm.

Akshay Venkatesh

We introduce a ``geometric'' method to bound periods of automorphic forms. The key features of this method are the use of equidistribution results in place of mean value theorems, and the systematic use of mixing and the spectral gap. Applications are given to equidistribution of sparse subsets of horocycles and to equidistribution of CM points; to s

L. Yu. Glebsky, E. I. Gordon, C. W. Henson

We introduce and discuss a definition of approximation of a topological algebraic system $A$ by finite algebraic systems of some class $\K$. For the case of a discrete algebraic system this definition is equivalent to the well-known definition of a local embedding of an algebraic system $A$ in a class $\K$ of algebraic systems. According to this definition $

Alexander Khodjamirian

The problem of hadronic input in charmless nonleptonic B decays is discussed. QCD sum rules and their light-cone versions (LCSR) provide an important part of this input, such as the decay constant $f_B$ and $B\to π$ form factor. Employing the LCSR technique, the $B\to ππ$ hadronic matrix elements with emission, penguin and annihilation topologies are calcula

Nestor Armesto, Larry McLerran, Carlos Pajares

We discuss forward-backward correlations in the mutliplicity of produced particles in heavy ion collisions. We find the Color Glass Condensate generates distinctive predictions for the long range component of this correlation. In particular, we predict the growth of the long range correlation with the centrality of the collision. We argue that the correlatio

Debasish Majumdar

The possibility to verify the pseudo-Dirac nature of neutrinos is investigated here via the detection of ultra high energy neutrinos from distant cosmological objects like GRBs. The very long baseline and the energy range from $\sim$ TeV to $\sim$ EeV for such neutrinos invokes the likelihood to probe very small pseude-Dirac splittings. The expected secondar

J. P. B. C. de Melo, T. Frederico, E. Pace, S. Pisano

Investigation of the spacelike and timelike electromagnetic form factors of hadrons, within a relativistic microscopical model characterized by a small set of hypothesis, could shed light on the components of hadron states beyond the valence one. Our relativistic approach has been successfully applied first to the pion and then the extension to the nucleon h

Laszlo Jenkovszky

Basing upon dual analytic models, we present arguments in favor of the parametrization of generalized parton distributions (GPD) in the form (x/g_0)^{(1-x)\tildeα(t)}, where \tildeα(t)=α(t)-α(0) is the nonlinear part of the Regge trajectory and g_0 is a parameter, g_0>1. For linear trajectories it reduces to earlier proposals. We compare the calculated momen

A. Acus, E. Norvaisas, D. O. Riska

The rational map approximation to the solution to the SU(2) Skyrme model with baryon number B=4 is canonically quantized. The quantization procedure leads to anomalous breaking of the chiral symmetry, and exponential falloff of the energy density of the soliton at large distances. The model is extended to SU(2) representations of arbitrary dimension. These s

E. Megias, E. Ruiz Arriola, L. L. Salcedo

We analyze the consequences of the inclusion of the gluonic Polyakov loop in chiral quark models at finite temperature. Specifically, the low-energy effective chiral Lagrangian from two such quark models is computed. The tree level vacuum energy density, quark condensate, pion decay constant and Gasser-Leutwyler coefficients are found to acquire a temperatur

B. Z. Kopeliovich, B. Povh, Ivan Schmidt

We present experimental evidences for the existence of a semi-hard scale in light hadrons. This includes the suppression of gluon radiation that is seen in high mass hadron diffraction; the weak energy dependence of hadronic total cross sections; the small value of the Pomeron trajectory slope measured in photoproduction of J/Psi; the weakness of gluon shado

P. F. Harrison, W. G. Scott, T. J. Weiler

In fermion mixing phenomenology, the matrix of moduli squared, P=(|U|^2), is well-known to carry essentially the same information as the complex mixing matrix U itself, but with the advantage of being phase-convention independent. The matrix K (analogous to the Jarlskog CP-invariant J) formed from the real parts of the mixing matrix "plaquette" produ

Shinya Kanemura, Daisuke Nomura, Koji Tsumura

Measurement of the Yukawa interaction between the top quark and the Higgs boson should be useful to clarify the mechanism of fermion mass generation. We discuss the impact of non-standard interactions characterized by dimension-six operators on the effective top Yukawa coupling. The cross section of the process $e^-e^+ \to W^-W^+ ν\bar ν\to t \bar t ν\bar ν$

D. S. Denisov, N. V. Mokhov, S. I. Striganov, M. A. Kostin

With a multi-stage collimation system and magnetic iron spoilers in the tunnel, the background particle fluxes on the ILC detector can be substantially reduced. At the same time, beam-halo interactions with collimators and protective masks in the beam delivery system create fluxes of muons and other secondary particles which can still exceed the tolerable le

The BABAR Collaboration, B. Aubert

We present a preliminary measurement of CP-violation parameters in the decay B0 -> K+K-K0, using approximately 347 million BBbar events collected by the BABAR detector at SLAC. Reconstructing the neutral kaon as KS -> pi+pi-, KS -> pi0pi0, or KL, we analyze the Dalitz plot distribution and measure fractions to intermediate states. We extract CP parameters fr

The BABAR Collaboration, B. Aubert

We report measurements of the inclusive electron momentum spectra in decays of charged and neutral B mesons, and of the ratio of semileptonic branching fractions ${\cal B}\xspace(\B^+ \to X e ν)$ and ${\cal B}\xspace(\B^0 \to X e ν)$. These were performed on a sample of 231 million $B\kern 0.18em\bar{\kern -0.18em B}{}\xspace$ events recorded with the \mbox{

The BABAR Collaboration, B. Aubert

We report on a search for the rare decay modes $B^+\to e^+ ν_e$ and $B^+\to μ^+ ν_μ$ with data collected from the BaBar detector at the PEP-II $e^+e^-$ storage ring. This search utilizes a new technique in which we fully reconstruct the accompanying $B^-$ in $Υ(4S)\righarrow B^+ B^-$ events, and look for a mono-energetic lepton in the $B^+$ rest frame. No si

The BABAR Collaboration, B. Aubert

We present an updated measurement of the time-dependent CP-violating asymmetry in B0->K0S K0S K0S decays based on 347 million Upsilon(4S)->B Bbar decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. We obtain the CP asymmetries S_f = -0.66 +/- 0.26 +/- 0.08 and C_f = -0.14 +/- 0.22 +/- 0.05, where the first uncertaintie

The BABAR Collaboration, B. Aubert

We present a measurement of the Cabibbo-Kobayashi-Maskawa CP-violating phase gamma with a Dalitz analysis of neutral D-meson decays to the K^0_s pi^- pi^+ final state from B^+/- -> D^{(*)}K^+/- decays, using a sample of 347 million B\bar{B} events collected by the BaBar detector. We measure gamma = (92 +/- 41 +/- 11 +/- 12)deg, where the first error is stati

T. Garidi, J-P. Gazeau, S. Rouhani, M. V. Takook

In the present work the massless vector field in the de Sitter (dS) space has been quantized. "Massless" is used here by reference to conformal invariance and propagation on the dS light-cone whereas "massive" refers to those dS fields which contract at zero curvature unambiguously to massive fields in Minkowski space. Due to the gauge invari

Andrea Passamonti

This thesis investigates in the time domain a particular class of second order perturbations of a perfect fluid non-rotating compact star: those arising from the coupling between first order radial and non-radial perturbations. This problem has been treated by developing a gauge invariant formalism based on the 2-parameter perturbation theory (Sopuerta, Brun

S. G. Ghosh, D. W. Deshkar

The general solution of the Einstein equation for higher dimensional (HD) spherically symmetric collapse of inhomogeneous dust in presence of a cosmological term, i.e., exact interior solutions of the Einstein field equations is presented for the HD Tolman-Bondi metrics imbedded in a de Sitter background. The solution is then matched to exterior HD Scwarschi

J. Mark Heinzle, N. Rohr, C. Uggla

In this letter we discuss the connection between so-called homoclinic chaos and the violation of energy conditions in locally rotationally symmetric Bianchi type IX models, where the matter is assumed to be non-tilted dust and a positive cosmological constant. We show that homoclinic chaos in these models is an artifact of unphysical assumptions: it requires

M. Sharif, M. Jamil Amir

This paper is devoted to investigate the teleparallel versions of the Friedmann models as well as the Lewis-Papapetrou solution. We obtain the tetrad and the torsion fields for both the spacetimes. It is shown that the axial-vector vanishes for the Friedmann models. We discuss the different possibilities of the axial-vector depending on the arbitrary functio

V. A. Belinski

A new argument is presented confirming the point of view that a Schwarzschild black hole formed during a collapse process does not radiate.

Stanimir Andonov

The sixth product level called compliant product is a connecting element between the physical product characteristics and the strategy of the producer company. The article discusses the differentiation among the product offers of companies working in the global markets, as well as the strategies which they use and could use in that respect.

Jean Dezert, Albena Tchamova, Florentin Smarandache, Pavlina Konstantinova

In this paper we consider and analyze the behavior of two combinational rules for temporal (sequential) attribute data fusion for target type estimation. Our comparative analysis is based on Dempster's fusion rule proposed in Dempster-Shafer Theory (DST) and on the Proportional Conflict Redistribution rule no. 5 (PCR5) recently proposed in Dezert-Smarand

Karl Crary, Robert Harper

This article responds to a critique of higher-order abstract syntax appearing in Logic Column 14, ``Nominal Logic and Abstract Syntax'', cs.LO/0511025.

Alireza Saffarzadeh, Ali A. Shokri

Using a quantum theory including spin-splitting effect in diluted magnetic semiconductors, we study the dependence of tunneling magnetoresistance (TMR) on barrier thickness, temperature and applied voltage in GaMnAs/GaAs/GaMnAs heterostructures. TMR ratios more than 65% are obtained at zero temperature, when one GaAs monolayer ($\approx$ 0.565 nm) is used as

Jan O. Haerter, Michael R. Peterson, B. Sriram Shastry

We present a finite temperature ($T$) study of the t-J model on the two-dimensional triangular lattice for the negative hopping $t$, as relevant for the electron-doped Na$_x$CoO$_2$ (NCO). To understand several aspects of this system, we study the $T$-dependent chemical potential, specific heat, magnetic susceptibility, and the dynamic Hall-coefficient acros

J. Pittler, W. Bu, D. Vaknin, A. Travesset

Anionic DMPA monolayers spread on LaCl$_3$ solutions reveal strong cation adsorption and a sharp transition to surface overcharging at unexpectedly low bulk salt concentrations. We determine the surface accumulation of La$^{3+}$ with anomalous x-ray reflectivity and find that La$^{3+}$ compensates the lipid surface charge by forming a Stern layer with $\appr

Paata Kakashvili, Henrik Johannesson, Sebastian Eggert

We calculate the finite-temperature local spectral weight (LSW) of a Luttinger liquid with an "open" (hard wall) boundary. Close to the boundary the LSW exhibits characteristic oscillations indicative of spin-charge separation. The line shape of the LSW is also found to have a Fano-like asymmetry, a feature originating from the interplay between elec

Latha Venkataraman, Jennifer E. Klare, Colin Nuckolls, Mark S. Hybertsen

The conductance of a single metal-molecule-metal junction depends critically on the conformations of the molecule. In the simple case of a biphenyl, two phenyl rings linked together by a single C-C bond, the conductance is expected to depend on the relative twist angle between the two rings, with the planar conformation having the highest conductance. A numb

L. L. Bonilla, A. Carpio, J. C. Neu, W. G. Wolfer

The formation and growth of helium bubbles due to self-irradiation in plutonium has been modelled by a discrete kinetic equations for the number densities of bubbles having $k$ atoms. Analysis of these equations shows that the bubble size distribution function can be approximated by a composite of: (i) the solution of partial differential equations describin

M. Camarda, F. Siringo, R. Pucci, A. Sudbo

The geometric properties of critical fluctuations in the 3D XY model are analyzed. The 3D XY model is a lattice model describing superfluids. We present a direct evaluation of the Hausdorff dimension D_H of the vortex loops which are the critical fluctuations of the 3D XY model. We also present analytical arguments for why \vartheta in the scaling relation η

T. Hanney

A general class of mass transport models with Q species of conserved mass is considered. The models are defined on a lattice with parallel discrete time update rules. For one-dimensional, totally asymmetric dynamics we derive necessary and sufficient conditions on the mass transfer dynamics under which the steady state factorises. We generalise the model to

I. M. Merhasin, Boris A. Malomed, Y. B. Band

We construct families of incoherent matter-wave solitons in a repulsive degenerate Bose gas trapped in an optical lattice (OL), i.e., gap solitons, and investigate their stability at zero and finite temperature, using the Hartree-Fock-Bogoliubov equations. The gap solitons are composed of a coherent condensate, and normal and anomalous densities of incoheren

Y. Nakajima, H. Shishido, H. Nakai, T. Shibauch

We present a systematic study of the dc-resistivity, Hall effect, and magnetoresistance in the normal state of quasi 2D heavy fermion superconductors CeMIn5 (M: Rh and Co) under pressure. Here the electronic system evolves with pressure from an antiferromagnetic (AF) metal, through a highly unconventional non-Fermi liquid, and finally into a Fermi-liquid sta

M. N. Popescu, S. Dietrich, G. Oshanin

We study the equilibrium properties of a model for a binary mixture of catalytically-reactive monomers adsorbed on a two-dimensional substrate decorated by randomly placed catalytic bonds. The interacting $A$ and $B$ monomer species undergo continuous exchanges with particle reservoirs and react ($A + B \to \emptyset$) as soon as a pair of unlike particles a

T. L. Schmidt, A. Komnik, A. O. Gogolin

We analyze the full counting statistics of charge transfer through a quantum dot in the Kondo regime, when coupled to an arbitrary number of terminals N. At the unitary Kondo fixed point and for N>2 we recover distinct anticorrelations of currents in concurring transport channels, which are related to the fermionic Hanbury Brown and Twiss (HBT) antibunching.

Klaus Kassner

It is demonstrated that the description of surface-diffusion controlled dynamics via the phase-field method is less trivial than it appears at first sight. A seemingly straightforward approach previously used in the literature is shown to fail to produce the correct asymptotics, albeit in a subtle manner. An apparently obvious alternative fails for a complem

J. C. Phillips

ARPES and wide area, high resolution STM studies of a micaceous cuprate high temperature superconductor have shown strong nanoscale gap disorder, but the question of whether this disorder is intrinsic and necessary for HTSC, or merely incidental to either this material, or even only its surface, appears to be an open one. We present the case that it is merel

Félix Werner, Yvan Castin

We consider N atoms trapped in an isotropic harmonic potential, with s-wave interactions of infinite scattering length. In the zero-range limit, we obtain several exact analytical results: mapping between the trapped problem and the free-space zero-energy problem, separability in hyperspherical coordinates, SO(2,1) hidden symmetry, and relations between the

S. I. Denisov, T. V. Lyutyy, P. Hänggi, K. N. Trohidou

We study dynamical and thermal effects that are induced in nanoparticle systems by a rotating magnetic field. Using the deterministic Landau-Lifshitz equation and appropriate rotating coordinate systems, we derive the equations that characterize the steady-state precession of the nanoparticle magnetic moments and study a stability criterion for this type of

Steffen Bohn, Marcelo O. Magnasco

We minimize the dissipation rate of an electrical network under a global constraint on the sum of powers of the conductances. We construct the explicit scaling relation between currents and conductances, and show equivalence to a a previous model [J. R. Banavar {\it et al} Phys. Rev. Lett. {\bf 84}, 004745 (2000)] optimizing a power-law cost function in an a

T. Abete, A. de Candia, E. Del Gado, A. Fierro

We study the structure and the dynamics in the formation of irreversible gels by means of molecular dynamics simulation of a model system where the gelation transition is due to the random percolation of permanent bonds between neighboring particles. We analyze the heterogeneities of the dynamics in terms of the fluctuations of the intermediate scattering fu

J. Hemberger, H. -A. Krug von Nidda, V. Tsurkan, A. Loidl

A detailed investigation of ZnCr2Se4 is presented which is dominated by strong ferromagnetic exchange but orders antiferromagnetically at T_N = 21 K. Specific heat C and thermal expansion Delta L/L exhibit sharp first-order anomalies at the antiferromagnetic transition. T_N is strongly reduced and shifted to lower temperatures by external magnetic fields and

Yukinori Ono, Jean-Francois Morizur, Katsuhiko Nishiguchi, Kei Takashina

We investigate transport in phosphorus-doped buried-channel metal-oxide-semiconductor field-effect transistors at temperatures between 10 and 295 K. In a range of doping concentration between around 2.1 and 8.7 x 1017 cm-3, we find that a clear peak emerges in the conductance versus gate-voltage curves at low temperature. In addition, temperature dependence

Hitoshi Seo, Kenji Tsutui, Masao Ogata, Jaime Merino

Effects of geometrical frustration in low-dimensional charge ordering systems are theoretically studied, mainly focusing on dynamical properties. We treat extended Hubbard models at quarter-filling, where the frustration arises from competing charge ordered patterns favored by different intersite Coulomb interactions, which are effective models for various c

J. Bourassa, B. Roostaei, R. Cote, H. A. Fertig

Recent experiments on strongly correlated bilayer quantum Hall systems strongly suggest that, contrary to the usual assumption, the electron spin degree of freedom is not completely frozen either in the quantum Hall or in the compressibles states that occur at filling factor $ν=1.$ These experiments imply that the quasiparticles at $ν=1$ could have both spin

L. L. Bonilla, A. Carpio, Y. Farjoun, J. C. Neu

Transient homogeneous nucleation is studied in the limit of large critical sizes. Starting from pure monomers, three eras of transient nucleation are characterized in the classic Becker-Döring kinetic equations with the Turnbull-Fisher discrete diffusivity. After an initial stage in which the number of monomers decreases, many clusters of small size are prod

Kazutaka Takahashi, Tomosuke Aono

We study the transport properties of an Aharonov-Bohm ring containing two quantum dots. One of the dots has well-separated resonant levels, while the other is chaotic and is treated by random matrix theory. We find that the conductance through the ring is significantly affected by mesoscopic fluctuations. The Breit-Wigner resonant peak is changed to an antir

Qinghong Cui, Chia-Ren Hu, J. Y. T. Wei, Kun Yang

The Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state has received renewed interest recently due to the experimental indication of its presence in CeCoIn$_5$, a quasi 2-dimensional (2D) d-wave superconductor. However direct evidence of the spatial variation of the superconducting order parameter, which is the hallmark of the FFLO state, does not yet exist. In th

R. Escamilla, L. Huerta

Polycrystalline samples of NbB2+x with nominal composition (B/Nb) = 2.0, 2.1, 2.2, 2.3, 2.4 and 2.5 were studied by X-ray photoelectron spectroscopy (XPS). The spectra revealed Nb and B oxides on the surface of the samples, mainly B2O3 and Nb2O5. After Ar ion etching the intensity of Nb and B oxides decreased. The Nb 3d5/2 and B 1s core levels associated wit

Linhua Jiang, Xiaohui Fan, Dean C. Hines, Yong Shi

We present Spitzer observations of thirteen z~6 quasars using the Infrared Array Camera (IRAC) and Multiband Imaging Photometer for Spitzer (MIPS). All the quasars except SDSS J000552.34-000655.8 (SDSS J0005-0006) were detected with high S/N in the four IRAC channels and the MIPS 24um band, while SDSS J0005-0006 was marginally detected in the IRAC 8.0um band

Geoffrey C. Bower, W. M. Goss, Heino Falcke, Donald C. Backer

We present new high-resolution observations of Sagittarius A* at wavelengths of 17.4 to 23.8 cm with the Very Large Array in A configuration with the Pie Town Very Long Baseline Array antenna. We use the measured sizes to calibrate the interstellar scattering law and find that the major axis size of the scattering law is smaller by ~6% than previous estimate

S. R. Pottasch, J. Bernard-Salas

A summary is given of planetary nebulae abundances from ISO measurements. It is shown that these nebulae show abundance gradients (with galactocentric distance), which in the case of neon, argon, sulfur and oxygen (with four exceptions) are the same as HII regions and early type star abundance gradients. The abundance of these elements predicted from these g

F. Calura, F. Matteucci

We compute the type Ia, Ib/c and II supernova (SN) rates as functions of the cosmic time for galaxies of different morphological types. We use four different chemical evolution models, each one reproducing the features of a particular morphological type: E/S0, S0a/b, Sbc/d and Irr galaxies. We essentially describe the Hubble sequence by means of decreasing e