July 2006 arXiv papers — page 9

Arnau Rios, Artur Polls, Jerome Margueron

Neutrino propagation in protoneutron stars requires the knowledge of the composition as well as the dynamical response function of dense hadronic matter. Matter at very high densities is probably composed of other particles than nucleons and little is known on the Fermi liquid properties of hadronic multicomponent systems. We will discuss the effects that th

A. I. Titov, B. Kämpfer, S. Daté, Y. Ohashi

We analyze the possibility to produce an intermediate Theta^+ via a KN->Θ+ formation process in gamma D-> pK^- X (X=nK^+,pK^0) reactions at some specific kinematical conditions, in which a pK^- pair is knocked out in the forward direction and its invariant mass is close to the mass of Lambda(1520). The Θ^+ signal may appear in the [γD,pK^-] missing mass dist

O. Plohl, C. Fuchs

It is a well known fact that Dirac phenomenology of nuclear forces predicts the existence of large scalar and vector mean fields in matter. To analyse the relativistic self-energy in a model independent way, modern high precision nucleon-nucleon ($NN$) potentials are mapped on a relativistic operator basis using projection techniques. This allows to compare

A. B. McIntosh, S. Hudan, C. J. Metelko, R. T. de Souza

We examine the decay of the 3.03 MeV state of $^8$Be evaporated from an excited projectile-like fragment following a peripheral heavy-ion collision. The relative energy of the daughter $α$ particles exhibits a dependence on the decay angle of the $^8$Be$^*$, indicative of a tidal effect. Comparison of the measured tidal effect with a purely Coulomb model sug

Goutami Bandyopadhyay, Surajit Chattopadhyay

Present paper endeavors to forecast the population of India through Artificial Neural Network. A non-linear Artificial Neural Net model has been developed and the prediction has been found to be sufficiently accurate. It has been found that the model is performing more efficiently in predicting female population than the male population. Results have been pr

R G Shandil, Jagjit Singh

Results obtained by Joseph ({\it J. Fluid Mech.} {\bf 33} (1968) 617) for the viscous parallel shear flow problem are extended to the problem of viscous parallel, shear flow problem in the beta plane and a sufficient condition for stability has also been derived.

C. Daskaloyannis And Y. Tanoudes

There are two classes of quantum integrable systems on a manifold with quadratic integrals, the Liouville and the Lie integrable systems as it happens in the classical case. The quantum Liouville quadratic integrable systems are defined on a Liouville manifold and the Schrödinger equation can be solved by separation of variables in one coordinate system. The

Anthony Licata

We construct geometric realizations of the r-colored bosonic and fermionic Fock space on the equivariant cohomology of the moduli space of framed rank r torsion-free sheaves on CP^2. Using these constructions, we realize geometrically all level one irreducible representations of the affine Lie algebra \hat{gl(r)}. The cyclic group Z_k acts naturally on the m

Bryan Clair

Suppose $Y$ is a regular covering of a graph $X$ with covering transformation group $π= \mathbb{Z}$. This paper gives an explicit formula for the $L^2$ zeta function of $Y$ and computes examples. When $π= \mathbb{Z}$, the $L^2$ zeta function is an algebraic function. As a consequence it extends to a meromorphic function on a Riemann surface. The meromorphic

Bernard Bercu, Wlodzimierz Bryc

We prove that if a rectangular matrix with uniformly small entries and approximately orthogonal rows is applied to the independent standardized random variables with uniformly bounded third moments, then the empirical CDF of the resulting partial sums converges to the normal CDF with probability one. This implies almost sure convergence of empirical periodog

Samangi Munasinghe, Emil J. Straube

We provide geometric conditions on the set of boundary points of infinite type of a smooth bounded pseudoconvex domain in $\mathbb{C}^{n}$ which imply that the $\bar{\partial}$-Neumann operator is compact. These conditions are formulated in terms of certain short time flows in suitable complex tangential directions. It is noteworthy that compactness is \emph

Valery Alexeev

The Minimal Model Program offers natural higher-dimensional analogues of stable $n$-pointed curves and maps: stable pairs consisting of a projective variety $X$ of dimension $\ge2$ and a divisor $B$, that should satisfy a few simple conditions, and stable maps $f:(X,B)\to Y$. Although MMP remains conjectural in higher dimensions, in several important situati

Marc Kesseböhmer, Mehdi Slassi

We study limit laws for return time processes defined on infinite conservative ergodic measure preserving dynamical systems. Especially for the critical cases with purely atomic limiting distribution we derive distorted processes posessing non-degenerated limits. For these processes also large deviation asymptotics are stated. The Farey map is used as an ill

Claire David, Rasika Fernando, Zhaosheng Feng

The goal of this note is to construct a class of traveling solitary wave solutions for the compound Burgers-Korteweg-de Vries equation by means of a hyperbolic ansatz.

Chongying Dong, Cuipo Jiang

It is shown that a simple vertex operator algebra V is rational if and only if its Zhu algebra A(V) is semisimple and each irreducible admissible V-module is ordinary. A contravariant form on a Verma type admissible V-module is constructed and the radical is exactly the maximal proper submodule. As an application the rationality of V_L^+ for any positive def

F. Monserrat

Denoting by ${\mathcal L}_d(m_0,m_1,...,m_r)$ the linear system of plane curves passing through $r+1$ generic points $p_0,p_1,...,p_r$ of the projective plane with multiplicity $m_i$ (or larger) at each $p_i$, we prove the Harbourne-Hirschowitz Conjecture for linear systems ${\mathcal L}_d(m_0,m_1,...,m_r)$ determined by a wide family of systems of multiplic

Pierre Jammes

Short survey about small eigenvalues of the Hodge Laplacian under bounded curvature collapsing.

Lawrence Roberts

The paper describes how known results in Heegaard-Floer homology apply to all known examples of rational blow-downs, and provides several new four dimensional pieces which could be exchanged while preserving some of the Ozsváth-Szabó four manifold invariants, when one of these pieces is found embedded in a smooth four manifold.

Ana Rita Martins

The notion of microsupport and regularity for ind-sheaves was introduced by M. Kashiwara and P. Schapira in "Microlocal study of ind-sheaves I: microsupport and regularity". In this paper we study the behaviour of the microsupport under several functorial operations and characterize "microlocally" the ind-sheaves that are regular along involu

Filippo Bracci, Manuel D. Contreras, Santiago Diaz-Madrigal

We characterize infinitesimal generators of semigroups of holomorphic self-maps of strongly convex domains using the pluricomplex Green function and the pluricomplex Poisson kernel. Moreover, we study boundary regular fixed points of semigroups. Among other things, we characterize boundary regular fixed points both in terms of the boundary behavior of infini

Tom Sanders

We prove a theorem claimed in math.CA/0605519 which asserts that if A is a subset of a compact abelian group G with density of a particular (natural, although technical) form then the A(G)-norm (that is the sum of the absolute values of the Fourier transform) of the characteristic function of A cannot be too small.

Klaus Fleischmann, Carl Mueller, Pascal Vogt

In a recent work, Fleischmann and Mueller (2004) showed the existence of a super-Brownian motion in R^d, d=2,3, with extra birth at the origin. Their construction made use of an analytical approach based on the fundamental solution of the heat equation with a one point potential worked out by Albeverio et al. (1995). The present note addresses two properties

Roberto Monti, Matthieu Rickly

We characterize convex isoperimetric sets in the Heisenberg group endowed with horizontal perimeter. We first prove Sobolev regularity for a certain class of vector fields in the plane with bounded variation, related to the curvature equations. Then, by an approximation-reparameterization argument, we show that the boundary of convex isoperimetric sets is fo

V Uma

Let $X(Δ)$ be the real toric variety associated to a smooth fan $Δ$. The main purpose of this article is: (i) to determine the fundamental group and the universal cover of $X(Δ)$, (ii) to give necessary and sufficient conditions on $Δ$ under which $π_1(X(Δ))$ is abelian, (iii) to give necessary and sufficient conditions on $Δ$ under which $X(Δ)$ is aspherica

Momo Bangoura

In this work, we define the quasi-Poisson Lie quasigroups, dual objects to the quasi-poisson Lie groups and we establish the correspondance between the local quasi-Poisson Lie quasigroups and quasi-Lie bialgebras (up to isomorphism)

Q X Yang

In this paper, we characterize the symbol in Hörmander symbol class $S^{m}_{ρ,δ} (m\in R, ρ,δ\geq 0)$ by its wavelet coefficients. Consequently, we analyse the kernel-distribution property for the symbol in the symbol class $S^{m}_{ρ,δ} (m\in R, ρ>0, δ\geq 0)$ which is more general than known results; for non-regular symbol operators, we establish sharp $L^{

A Jensen, M Krishna

In this paper we give some new criteria for identifying the components of a probability measure, in its Lebesgue decomposition. This enables us to give new criteria to identify spectral types of self-adjoint operators on Hilbert spaces, especially those of interest.

Q X Yang

Given a Calderón--Zygmund (C--Z for short) operator $T$, which satisfies Hörmander condition, we prove that: if $T$ maps all the characteristic atoms to $WL^{1}$, then $T$ is continuous from $L^{p}$ to $L^{p}(1<p<\infty)$. So the study of strong continuity on arbitrary function in $L^{p}$ has been changed into the study of weak continuity on characteristic f

Anca Iuliana Bonciocat, Alexandru Zaharescu

We obtain explicit upper bounds for the number of irreducible factors for a class of compositions of polynomials in several variables over a given field. In particular, some irreducibility criteria are given for this class of compositions of polynomials.

N Anuradha

Let $p$ and $l$ be rational primes such that $l$ is odd and the order of $p$ modulo $l$ is even. For such primes $p$ and $l$, and for $e=l, 2l$, we consider the non-singular projective curves $aY^e = bX^e + cZ^e$ ($abc \neq 0$) defined over finite fields $\mathbf{F}_q$ such that $q=p^α\equiv 1(\bmod {e})$. We see that the Fermat curves correspond precisely t

Claire David, Pierre Sagaut

The goal of this work is to determine classes of traveling Solitary wave solutions for a differential approximation of a finite difference scheme by means of a hyperbolic ansatz.

Y. Simsek, T. Kim, D. Kim

In this paper, we consstruct a new extended q-Bernoulli numbers and poly nomials. From these numbers, we derive the multiple zeta functions and give some relations between multiple Bernoulli numbers and multiple zeta functions.

A Venkatlaxmi, B S Padmavathi, T Amaranath

The completeness of solutions of homogeneous as well as non-homogeneous unsteady Stokes equations are examined. A necessary and sufficient condition for a divergence-free vector to represent the velocity field of a possible unsteady Stokes flow in the absence of body forces is derived.

Mohsen Alimohammady

Suppose $Π_1(E, F)$ is the space of all absolutely 1-summing operators between two Banach spaces $E$ and $F$. We show that if $F$ has a copy of $c_0$, then $Π_1(E, F)$ will have a copy of $c_0$, and under some conditions if $E$ has a copy of $\ell_1$ then $Π_1(E, F)$ would have a complemented copy of $\ell_1$.

Mridula Garg, Shweta Mittal

In the present paper we derive a unified new integral whose integrand contains products of Fox $H$-function and a general class of polynomials having general arguments. A large number of integrals involving various simpler functions follow as special cases of this integral.

Ph. Feinsilver, R. Schott

Solving analytic systems using inversion can be implemented in a variety of ways. One method is to use Lagrange inversion and variations. Here we present a different approach, based on dual vector fields. For a function analytic in a neighborhood of the origin in the complex plane, we associate a vector field and its dual, an operator version of Fourier tran

Lek-Heng Lim

We propose a theory of eigenvalues, eigenvectors, singular values, and singular vectors for tensors based on a constrained variational approach much like the Rayleigh quotient for symmetric matrix eigenvalues. These notions are particularly useful in generalizing certain areas where the spectral theory of matrices has traditionally played an important role.

Stephen Lack

We study 2-monads and their algebras using a Cat-enriched version of Quillen model categories, emphasizing the parallels between the homotopical and 2-categorical points of view. Every 2-category with finite limits and colimits has a canonical model structure in which the weak equivalences are the equivalences; we use these to construct more interesting mode

Stefan Wenger

In this paper we study a homological version of the higher-dimensional divergence invariants defined by Brady and Farb. We show that they are quasi-isometry invariants in the class of proper cocompact Hadamard spaces in the sense of Alexandrov and that they can moreover be used to detect the Euclidean rank of such spaces. We thereby extend results of Brady-F

J. Martin Lindsay, Stephen J. Wills

A recent characterisation of Fock-adapted contraction operator stochastic cocycles on a Hilbert space, in terms of their associated semigroups, yields a general principle for the construction of such cocycles by approximation of their stochastic generators. This leads to new existence results for quantum stochastic differential equations. We also give necess

Fabrizio Zanello

$(1,3,6,10,15,21,28,27,27,28)$ is a level $h$-vector! This example answers negatively the open question as to whether all codimension 3 level $h$-vectors are unimodal. Moreover, using the same (simple) technique, we are able to construct level algebras of codimension 3 whose $h$-vectors have exactly $N$ ` ` maxima&#34;, for any positive integer $N$. These no

Zhi-Wei Sun

For integers a and n>0, let a(n) denote the residue class {x\in Z: x=a (mod n)}. Let A be a collection {a_s(n_s)}_{s=1}^k of finitely many residue classes such that A covers all the integers at least m times but {a_s(n_s)}_{s=1}^{k-1} does not. We show that if n_k is a period of the covering function w_A(x)=|{1\le s\le k: x\in a_s(n_s)}| then for any r=0,...

Anton Deitmar

Using the approach of Kurokawa, Ochiai, and Wakayama to &#39;absolute mathematics&#39; we define a corresponding notion of schemes.

Michael Gutperle, Darya Krym

The decay of highly excited massive string states in compactified heterotic string theories is discussed. We calculate the decay rate and spectrum of states carrying momentum and winding in the compactified direction. The longest lived states in the spectrum are near BPS states whose decay is dominated by a single decay channel of massless radiation which br

C. Adam, J. Sanchez-Guillen, A. Wereszczynski

We study the issue of stability of static soliton-like solutions in some non-linear field theories which allow for knotted field configurations. Concretely, we investigate the AFZ model, based on a Lagrangian quartic in first derivatives with infinitely many conserved currents, for which infinitely many soliton solutions are known analytically. For this mode

G. C. Rossi

In this talk I would like to illustrate with examples taken from Quantum Field Theory and Biophysics how an intelligent exploitation of the unprecedented power of today&#39;s computers could led not only to the solution of pivotal problems in the theory of Strong Interactions, but also to the emergence of new lines of interdisciplinary research, while at the

Harald Grosse, Michael Wohlgenannt

Field theories on deformed spaces suffer from the IR/UV mixing and renormalization is generically spoiled. In work with R. Wulkenhaar, one of us realized a way to cure this disease by adding one more marginal operator. We review these ideas, show the application to $ϕ^3$ models and use the heat kernel expansion methods for a scalar field theory coupled to an

A. Niégawa, M. Inui, H. Kohyama

In Coulomb gauge QCD in the Lagrangian formalism, energy divergences arise in individual diagrams. We give a proof on cancellation of these divergences to all orders of perturbation theory without obstructing the algebraic renormalizability of the theory.

Greg Landsberg

One of the most dramatic consequences of low-scale (~1 TeV) quantum gravity in models with large or warped extra dimension(s) is copious production of mini black holes at future colliders and in ultra-high-energy cosmic ray collisions. Hawking radiation of these black holes is expected to be constrained mainly to our three-dimensional world and results in ri

Antonio D. Polosa, Carlos A. Salgado

We present general arguments, based on medium-induced radiative energy loss, which reproduce the non-gaussian shapes of away-side di-jet azimuthal correlations found in nucleus-nucleus collisions at RHIC. A rather simple generalization of the Sudakov form factors to opaque media allowing an effective description of the experimental data is proposed.

Arttu Rajantie, Anders Tranberg

Truncations of the 2PI effective action are seen as a promising way of studying non-equilibrium dynamics in quantum field theories. We probe their applicability in the non-perturbative setting of topological defect formation in a symmetry-breaking phase transition, by comparing full classical lattice field simulations and the 2PI formulation for classical fi

P. V. Dong, D. T. Huong, Tr. T. Huong, H. N. Long

We show that, in frameworks of the economical 3-3-1 model, all fermions get masses. At the tree level, one up-quark and two down-quarks are massless, but the one-loop corrections give all quarks the consistent masses. This conclusion is in contradiction to the previous analysis in which, the third scalar triplet has been introduced. This result is based on t

Yu Jia

Baryons made of three heavy quarks become weakly coupled, when all the quarks are sufficiently heavy such that the typical momentum transfer is much larger than Lambda_QCD. We use variational method to estimate masses of the lowest-lying bcc, ccc, bbb and bbc states by assuming they are Coulomb bound states. Our predictions for these states are systematicall

Cristina Manuel

We explore the effects of an applied strong external magnetic field in a three flavor massless color superconductor. The long-range component of the B field that penetrates the superconductor enhances some quark condensates, leading to a different condensation pattern. The external field also reduces the flavor symmetries in the system, and thus it changes d

D. Falcone

A brief overview of the phenomenology related to the seesaw mechanism and the baryogenesis via leptogenesis is presented.

A. E. Inopin

This is a Comment to the recent 3 papers by S.S. Afonin

Manjari Bagchi, Monika Sinha, Mira Dey, Jishnu Dey

This paper is withdrawn by the authors, a better version is available as hep-ph/0505139.

Silas R. Beane, Paulo F. Bedaque, Thomas C. Luu, Kostas Orginos

We calculate the pi+ K+ scattering length in fully-dynamical lattice QCD with domain-wall valence quarks on MILC lattices with rooted staggered sea-quarks at a lattice spacing of b=0.125 fm, lattice spatial size of L =2.5 fm and at pion masses of m_pi=290, 350, 490 and 600 MeV. The lattice data, analyzed at next-to-leading order in chiral perturbation theory

M. Artuso, CLEO Collaboration

We examine e+e- to Ds- Ds*+ or Ds-* Ds+ collisions at 4170 MeV using the CLEO-c detector in order to measure the decay constant f_Ds+. We use the Ds+ to ell+ nu channel, where the ell+ designates either a mu+ or a tau+. Analyzing both modes simultaneously, we determine B(D_s^+ to mu+ nu)= (0.657 +- 0.090 +- 0.028)%, B(D_s^+ to tau+ nu)= (7.1 +- 1.4 +- 0.3)%,

B. Hoeneisen

B factories measure the CP violation parameter of B^0 Bbar^0 mixing and decay. Hadron colliders measure the dimuon charge asymmetry of an admixture of B hadrons. In this note we discuss a subtle point on how the CP violation parameter of B^0_s Bbar^0_s mixing and decay can be extracted from these measurements.

The BaBar Collaboration, B. Aubert

The photon spectrum in B -> X_s gamma decay, where X_s is any strange hadronic state, is studied using a data sample of 88.5 million e+e- -> Upsilon(4S) -> BBbar decays collected by the BaBar experiment at SLAC. The partial branching fraction, Delta B(B -> X_s gamma)=(3.67 +- 0.29(stat.) +- 0.34(sys.) +- 0.29(model)) times 10^-4, the first moment <E_gamma>=2

I. Shipsey

The role of charm in testing the Standard Model description of quark mixing and CP violation through measurements of lifetimes, decay constants and semileptonic form factors is reviewed. Together with Lattice QCD, charm has the potential this decade to maximize the sensitivity of the entire flavor physics program to new physics. and pave the way for understa

G. Bonvicini, CLEO Collaboration

Using 281/pb of data recorded by the CLEO-c detector observing e+e- collisions at the psi(3770), corresponding to 1.8 million D Dbar pairs, the substructure of the decay D+ to pi+ pi- pi+ is investigated using the Dalitz plot technique. The results presented in this document are preliminary.

The BABAR Collaboration, B. Aubert

We present a study of B semileptonic decays into charm final states based on 211.7 fb^{-1} of data collected at the Υ(4S) resonance with the babar detector at the pep2 e^+e^- storage ring. Using a novel technique based on the simultaneous fit of a set of variables reconstructed on the recoil of a B tagged in an hadronic decay mode, we measure the relative br

The BABAR Collaboration, B. Aubert

We report preliminary measurements of the exclusive charmless semileptonic branching fractions of the B+ --> eta l+ nu and B+ --> eta&#39; l+ nu decays. These measurements are based on 316 fb-1 of data collected at the Y(4S) resonance by the BABAR detector. In events in which the decay of one B meson to a hadronic final state is fully reconstructed, the semi

The BABAR Collaboration, B. Aubert

We search for decays of a B meson into a neutral D meson and a kaon, with the D meson decaying into K+pi-pi0. This final state can be reached through the b --> c transition B- -> D0K- followed by the doubly Cabibbo-suppressed D0 --> K+pi-pi0, or the b --> u transition B- --> D0bar K- followed by the Cabibbo-favored D0bar --> K+ pi-pi0. The interference of th

BABAR Collaboration, B. Aubert

A search for the decay B+ -> a0+pi0 with the a0+ decaying to an eta and a pi+ was carried out at the Stanford Linear Accelerator Center using the BABAR detector coupled with the PEP-II collider. The analysis used a data sample comprised of approximately 252 million BBbar pairs collected at the Upsilon(4S) resonance. No signal was observed and a 90% confidenc

The BaBar Collaboration, B. Aubert

We search for B0 meson decays into two-body combinations of K0, eta, eta&#39;, and phi mesons in 324 million B Bbar pairs collected with the BaBar detector at the PEP-II asymmetric-energy e+e- collider at SLAC. We measure the following branching fractions (upper limits at 90% confidence level) in units of 10^{-6}: Br(B0->eta K0) =1.8+0.7-0.6 +-0.1(2.9), Br(B

The BABAR Collaboration, B. Aubert

We report first observations of the decays B- to Ds(*)+ K- pi-, using 292 fb^-1 of data collected at Upsilon(4S) resonance energy by the BaBar detector at the PEP II e+ e- collider. The branching fractions are measured to be B(B- to Ds+ K- pi-) = (1.88 +- 0.13 +- 0.41) x 10^-4 and B(B- to Ds*+ K- pi-) = (1.84 +- 0.19 +- 0.40) X 10^-4.

Krzysztof Kurek

Measurements of the gluon polarization $\frac{ΔG}{G}$ via the open charm channel and based on the helicity asymmetry of large transverse-momentum hadrons in the final state are presented. The data have been collected in the years 2002-2004 by the COMPASS experiment at CERN using a 160 GeV/c polarized muon beam scattered off a polarized $^6$LiD target. The ne

C. Meusburger

We relate the geometrical and the Chern-Simons description of (2+1)-dimensional gravity for spacetimes of topology $R\times S_g$, where $S_g$ is an oriented two-surface of genus $g>1$, for Lorentzian signature and general cosmological constant and the Euclidean case with negative cosmological constant. We show how the variables parametrising the phase space

José M. M. Senovilla

Symmetric hyperbolic systems of equations are explicitly constructed for a general class of tensor fields by considering their structure as r-fold forms. The hyperbolizations depend on 2r-1 arbitrary timelike vectors. The importance of the so-called &#34;superenergy&#34; tensors, which provide the necessary symmetric positive matrices, is emphasized and made

A. de la Cruz-Dombriz, A. Dobado

In this work we consider the possibility of describing the current evolution of the universe, without the introduction of any cosmological constant or dark energy (DE), by modifying the Einstein-Hilbert (EH) action. In the context of the f(R) gravities within the metric formalism, we show that it is possible to find an action without cosmological constant wh

Gamal G. L Nashed

We show that the tetrad field whose metric gives the Reissner-Nordström anti-de Sitter black holes gives the correct value of energy in Møller tetrad theory of gravitation.

Emine Mese, Nurettin Pirinccioglu, Irfan Acikgoz, Figen Binbay

Performing a relativistic approximation as the generalization to a curved spacetime of the flat space Klein-Gordon equation, an effective Hamiltonian which includes non-minimial coupling between gravity and scalar field and also quartic self-interaction of scalar field term is obtained.

Gagan Aggarwal, S. Muthukrishnan, Jon Feldman

Many popular search engines run an auction to determine the placement of advertisements next to search results. Current auctions at Google and Yahoo! let advertisers specify a single amount as their bid in the auction. This bid is interpreted as the maximum amount the advertiser is willing to pay per click on its ad. When search queries arrive, the bids are

Rui Abreu, Peter Zoeteweij, Arjan JC van Gemund

Because of constraints imposed by the market, embedded software in consumer electronics is almost inevitably shipped with faults and the goal is just to reduce the inherent unreliability to an acceptable level before a product has to be released. Automatic fault diagnosis is a valuable tool to capture software faults without extra effort spent on testing. Ap

Marcin Kaminski, Vadim Lozin

We give the first polynomial-time algorithm for coloring vertices of P_5-free graphs with k colors. This settles an open problem and generalizes several previously known results.

Josiah Carlson, David Eppstein

We consider drawings of trees in which all edges incident to leaves can be extended to infinite rays without crossing, partitioning the plane into infinite convex polygons. Among all such drawings we seek the one maximizing the angular resolution of the drawing. We find linear time algorithms for solving this problem, both for plane trees and for trees witho

I. V. Tokatly, G. Vignale

We apply the methods of continuum mechanics to the study of the collective modes of the fractional quantum Hall liquid. Our main result is that at long wavelength there are {\it two} distinct modes of oscillations, while previous theories predicted only {\it one}. The two modes are shown to arise from the internal dynamics of shear stresses created by the Co

Shai Ronen, Daniele C. E. Bortolotti, John. L. Bohn

We study Bose-Einstein condensates with purely dipolar interactions in oblate (pancake) traps. We find that the condensate always becomes unstable to collapse when the number of particles is sufficiently large. We analyze the instability, and find that it is the trapped-gas analogue of the ``roton-maxon&#39;&#39; instability previously reported for a gas tha

W. H. Lau, V. Sih, N. P. Stern, R. C. Myers

Time-resolved Kerr rotation spectroscopy is used to monitor the room temperature electron spin dynamics of optical telecommunication wavelength AlInGaAs multiple quantum wells lattice-matched to InP. We found that electron spin coherence times and effective g-factors vary as a function of aluminum concentration. The measured electron spin coherence times of

Adolfo Avella, Ferdinando Mancini

The two-dimensional Hubbard model is studied within the Composite Operator Method (COM) with the residual self-energy computed in the Self-Consistent Born Approximation (SCBA). COM describes interacting electrons in terms of the new elementary excitations appearing in the system owing to strong correlations; residual interactions among these excitations are

Effrosyni Seitaridou, Mandar M. Inamdar, Rob Phillips, Kingshuk Ghosh

Using a microfluidics device filled with a colloidal suspension of microspheres, we test the laws of diffusion in the limit of small particle numbers. Our focus is not just on average properties such as the mean flux, but rather on the features of the entire distribution of allowed microscopic trajectories that are possible during diffusive dynamics. The exp

Alexander B. Dzyubenko

We discuss symmetry-driven squeezing and coherent states of few-particle systems in magnetic fields. An operator approach using canonical transformations and the SU(1,1) algebras is developed for considering Coulomb correlations in the lowest Landau levels.

Giovano O. Cardozo, Jose F. Fontanari

The nonequilibrium phase transition in the triplet-creation model is investigated using critical spreading and the conservative diffusive contact process. The results support the claim that at high enough diffusion the phase transition becomes discontinuous. As the diffusion probability increases the critical exponents change continuously from the ordinary d

Pai-Yi Hsiao

Properties of polyelectrolytes in tetravalent salt solutions are intensively investigated by a coarse-grained model. The concentration of salt and the size of tetravalent counterions are found playing a decisive role on chain properties. If the size of tetravalent counterions is compatible with the one of monomers, the chains show extended structures at low

C. J. Tessone, H. S. Wio

Here we present a study of stochastic resonance in an extended FitzHugh-Nagumo system with a field dependent activator diffusion. We show that the system response (here measured through the output signal-to-noise ratio) is enhanced due to the particular form of the non-homogeneous coupling. Such a result supports previous ones obtained in a simpler scalar re

Adriano Barra

We introduce a diagrammatic formulation for a cavity field expansion around the critical temperature. This approach allows us to obtain a theory for the overlap&#39;s fluctuations and, in particular, the linear part of the Ghirlanda-Guerra relationships (GG) (often called Aizenman-Contucci polynomials (AC)) in a very simple way. We show moreover how these co

Oded Hod, Roi Baer, Eran Rabani

Inelastic effects arising from electron-phonon coupling in molecular Aharonov-Bohm (AB) interferometers are studied using the nonequilibrium Green&#39;s function method. Results for the magnetoconductance are compared for different values of the electron-phonon coupling strength. At low bias voltages, the coupling to the phonons does not change the lifetime

W. Limmer, J. Daeubler, M. Glunk, T. Hummel

A new type of (Ga,Mn)As microstructures with laterally confined electronic and magnetic properties has been realized by growing (Ga,Mn)As films on [1-10]-oriented ridge structures with (113)A sidewalls and (001) top layers prepared on GaAs(001) substrates. The temperature- and field-dependent magnetotransport data of the overgrown structures are compared wit

A. Rodriguez-Prieto, V. M. Silkin, A. Bergara

Alkalies are considered to be simple metals at ambient conditions. However, recently reported theoretical and experimental results have shown an unexpected and intriguing correlation between complex structures and an enhanced superconducting transition temperature in lithium under pressure. In this article we analyze the pressure induced Fermi surface deform

J. Marciak-Kozlowska, M. Pelc, M. Kozlowski

In his paper the two mode Heaviside equation was formulated and solved. It was shown that the interaction of ultra-short laser pulses with matter leads to two mode excitation electrons and phonons which afterwards diffuse with finite velocities.

W. Limmer, M. Glunk, J. Daeubler, T. Hummel

General expressions for the longitudinal and transverse resistivities of single-crystalline cubic and tetragonal ferromagnets are derived from a series expansion of the resistivity tensor with respect to the magnetization orientation. They are applied to strained (Ga,Mn)As films, grown on (001)- and (113)A-oriented GaAs substrates, where the resistivities ar

M. Filibian, P. Carretta, T. Miyake, Y. Taguchi

$^7$Li and $^1$H NMR and magnetization measurements in \lpc (Pc$\equiv$C$_{32}$H$_{16}$N$_8$), recently proposed as a strongly correlated metal, are presented. Two different low-frequency dynamics are evidenced. The first one, probed by $^1$H nuclei gives rise to a slowly relaxing magnetization at low temperature and is associated with the freezing of MnPc $

Hidekazu Mukuda, Yoshio Kitaoka, Shintaro Ishiwata, Takashi Saito

We report on novel magnetic and electronic properties of SrCo6O11 that exhibits a unique stepwise magnetization and its relevant magnetotransport phenomena investigated by the site-selective 59Co nuclear magnetic resonance (NMR) at zero and applied magnetic fields. This compound is composed of three Co sites in the unit cell, i.e., Co(1) in the metallic Kago

E. Silva, N. Pompeo, S. Sarti, C. Amabile

We investigate the physics of the microwave response in YBa$_{2}$Cu$_{3}$O$_{7-δ}$, SmBa$_{2}$Cu$_{3}$O$_{7-δ}$ and MgB$_{2}$ in the vortex state. We first recall the theoretical basics of vortex-state microwave response in the London limit. We then present a wide set of measurements of the field, temperature, and frequency dependences of the vortex state mi

P. Fröbrich, P. J. Kuntz

The treatment of Heisenberg films with many-body Green&#39;s function theory (GFT) is reviewed. The basic equations of GFT are derived in sufficient detail so that the rest of the paper can be understood without having to consult further literature. The main part of the paper is concerned with applications of the formalism to ferromagnetic, antiferromagnetic

Aveek Bid, Achyut Bora, A. K. Raychaudhuri

We have measured the resistances (and resistivities) of Ag and Cu nanowires of diameters ranging from 15nm to 200nm in the temperature range 4.2K-300K with the specific aim to assess the applicability of the Bloch-Grüneisen formula for electron phonon resistivity in these nanowires. The wires were grown within polymeric templates by electrodeposition. We fin

Takaaki Monnai, Ayumu Sugita, Katsuhiro Nakamura

We explore the role of an intermediate state (phase) in homogeneous nucleation phenomenon by examining the decay process through a doubly-humped potential barrier. As a generic model we use the fourth- and sixth-order Landau potentials and analyze the Fokker-Planck equation for the one-dimensional thermal diffusion in the system characterized by a triple-wel