September 2006 arXiv papers — page 26

Y. Aritomo, M. Ohta, F. Hanappe

The fusion-fission process accompanied by neutron emission is studied in the superheavy-mass region on the basis of the fluctuation-dissipation model combined with a statistical model. The calculation of the trajectory or the shape evolution in the deformation space of the nucleus with neutron emission is performed. Each process (quasi-fission, fusion-fissio

Shelly L. Harvey

For any group G, we define a new characteristic series related to the derived series, that we call the torsion-free derived series of G. Using this series and the Cheeger-Gromov rho-invariant, we obtain new real-valued homology cobordism invariants rho_n for closed (4k-1)-dimensional manifolds. For 3-dimensional manifolds, we show that {rho_n} is a linearly

Vyacheslav M. Abramov, Fima C. Klebaner

Consider a time series with missing observations but a known final point. Using control theory ideas we estimate/predict these missing observations. We obtain recurrence equations which minimize sum of squares of a control sequence. An advantage of this method is in easily computable formulae and flexibility of its application to different structures of miss

Shinji Tanimoto

Dimensional analysis provides many simple and useful tools for various situations in science. The objective of this paper is to investigate its relations to functions, i.e., the dimensions for functions that yield physical quantities and those for the arguments of functions. In particular, it is shown that there are three types of functions from a viewpoint

Sadataka Furui, Hideo Nakajima

Effects of the quark field on the ghost propagator of the lattice Landau gauge are investigated by using the quenched gauge configuration of SU(2) first copy and the parallel tempering (PT) gauge fixed samples, quenched SU(3) $56^4$ configuration and unquenched SU(3) configurations produced by the MILC collaboration. We measure color symmetric and color anti

Andreas Bierwage, Qingquan Yu

The linear instability and nonlinear dynamics of collisional (resistive) and collisionless (due to electron inertia) double tearing modes (DTMs) are compared with the use of a reduced cylindrical model of a tokamak plasma. We focus on cases where two q = 2 resonant surfaces are located a small distance apart. It is found that regardless of the magnetic recon

Guy Bunin

A continuum description of unstructured meshes in two dimensions, both for planar and curved surface domains, is proposed. The meshes described are those which, in the limit of an increasingly finer mesh (smaller cells), and away from irregular vertices, have ideally-shaped cells (squares or equilateral triangles), and can therefore be completely described b

Andrew M. Childs, Aram W. Harrow, Pawel Wocjan

Schur duality decomposes many copies of a quantum state into subspaces labeled by partitions, a decomposition with applications throughout quantum information theory. Here we consider applying Schur duality to the problem of distinguishing coset states in the standard approach to the hidden subgroup problem. We observe that simply measuring the partition (a

Lee Smolin

We consider the hypothesis that quantum mechanics is an approximation to another, cosmological theory, accurate only for the description of subsystems of the universe. Quantum theory is then to be derived from the cosmological theory by averaging over variables which are not internal to the subsystem, which may be considered non-local hidden variables. We fi

Marie-Noelle Celerier, Laurent Nottale

In standard quantum mechanics, it is not possible to directly extend the Schrodinger equation to spinors, so the Pauli equation must be derived from the Dirac equation by taking its non-relativistic limit. Hence, it predicts the existence of an intrinsic magnetic moment for the electron and gives its correct value. In the scale relativity framework, the Schr

Fabio Sciarrino, Francesco De Martini

The optimal phase covariant cloning machine (PQCM) broadcasts the information associated to an input qubit into a multi-qubit systems, exploiting a partial a-priori knowledge of the input state. This additional a priori information leads to a higher fidelity than for the universal cloning. The present article first analyzes different experimental schemes to

D. I. Kamenev, G. P. Berman, V. I. Tsifrinovich

The errors caused by qubit displacements from their prescribed locations in an ensemble of spin chains are estimated analytically and calculated numerically for a quantum computer based on phosphorus donors in silicon. We show that it is possible to polarize (initialize) the nuclear spins even with displaced qubits by using Controlled NOT gates between the e

P. Barberis-Blostein, M. Bienert

We analyze the propagation of a pair of quantized fields inside a medium of three-level atoms in $Λ$ configuration. We calculate the stationary quadrature noise spectrum of the field after propagating through the medium, in the case where the probe field is in a squeezed state and the atoms show electromagnetically induced transparency (EIT). We find an osci

Miklós Csűrös, Laurent Noé, Gregory Kucherov

We propose that the distribution of DNA words in genomic sequences can be primarily characterized by a double Pareto-lognormal distribution, which explains lognormal and power-law features found across all known genomes. Such a distribution may be the result of completely random sequence evolution by duplication processes. The parametrization of genomic word

Sacha E. Kopp

Neutrino beams at from high-energy proton accelerators have been instrumental discovery tools in particle physics. Neutrino beams are derived from the decays of charged pi and K mesons, which in turn are created from proton beams striking thick nuclear targets. The precise selection and manipulation of the pi/K beam control the energy spectrum and type of ne

Alessandro Di Mare, Vito Latora

A way to simulate the basic interactions between two individuals with different opinions, in the context of strategic game theory, is proposed. Various games are considered, which produce different kinds of opinion formation dynamics. First, by assuming that all individuals (players) are equals, we obtain the bounded confidence model of continuous opinion dy

I. A. Soloshenko, V. N. Gorshkov, A. M. Zavalov

This paper reviews resent theoretical and experimental research on physical processes in compensated negative-ion beams. A previous review was published by one of the authors in Ref. [1]. The present paper summarizes the new results of numerical calculations of the stationary electric field in negative-ion beams, and the resent results of experimental studie

Luca Dall'Asta

The work presented in this thesis concerns different aspects of dynamical processes on networks. The first subject considered is the theoretical modeling of exploration processes of complex networks, such as the ``traceroute'' process used to map the Internet. Our mean-field analysis of the traceroute model provides a better understanding of the Inte

Chhaya Ravi Kant, P. Arun, Nupur Prakash

Global wireless networks enable mobile users to communicate regardless of their locations. Location management is an important part of the emerging wireless and mobile technology. A Personal Communication System (PCS) network must have an efficient way to keep track of the mobile users to deliver services effectively. Global System for Mobile Communication (

Evangelos Chaliasos

We give the correct interpretation of the new metric, found lately by the author. This metric results as an exact solution of the Einstein field equations, without the cosmological constant. The new feature is the introduction, from the beginning, of two rotations attributed to the Universe. As a result also an expanding, and indeed in accelerating rate, Uni

M. Ya. Amusia, A. S. Baltenkov, L. V. Chernysheva

We demonstrate rather interesting manifestations of co-existence of resonance features in characteristics of the photoionization of 3d-electrons in Xe@C60. It is shown that the reflection of photoelectrons produced by the 3d Xe photoionization affects greatly partial photoionization cross-sections of and levels and respective angular anisotropy parameters, b

V. A. Kuz'menko

The physical mechanism of phenomenon is explained as a result of inequality of forward and reversed processes in optics. The importance of experimental study of its invariance relation is discussed.

Arman Melkumyan

It is shown that surface waves with twelve different velocities in the cases of different magneto-electrical boundary conditions can be guided by the interface of two magneto-electro-elastic half-spaces. The plane boundary of one of the half-spaces is clamped while the plane boundary of the other one is free of stresses. The twelve velocities of propagation

Bernhard Rothenstein, Stefan Popescu

The uniformly accelerated reference frame described by Hamilton, Desloge and Philpott involves the observers who perform the hyperbolic motion with constant proper acceleration gi. They start to move from different distances measured from the origin O of the inertial reference frame K(XOY), along its OX axis with zero initial velocity. Equipped with clocks a

Luciano da Fontoura Costa

This article investigates the evolution of the $h-$index in a complex network including two communities (in the sense of having different features) with the same number of authors whose yearly productions follow the Zipf's law. Models considering indiscriminate citations, as well as citations preferential to the fitness values of each community and/or th

Charles B. Chiu, Rudolph C. Hwa

An event generator is constructed on the basis of a model of multiple scattering of partons so that the trajectory of a parton traversing a dense and expanding medium can be tracked. The parameters in the code are adjusted to fit the Δϕazimuthal distribution on the far side when the trigger momentum is in the non-perturbative region, p_T(trigger)<4 GeV/c. Th

Ad. R. Raduta, F. Gulminelli

We investigate the possibility to extract the symmetry energy from multifragmentation data. The applicability of the grandcanonical formula earlier proposed by Ono {\it et al.} [Phys. Rev. C {\bf 68}, 051601(R)] in the case of finite excited nuclei is tested within a microcanonical framework. Relatively good results are obtained except for large residual nuc

STAR Collaboration

We determine rapidity asymmetry in the production of charged pions, protons and anti-protons for large transverse momentum (pT) for d+Au collisions at \sqrt s_NN = 200 GeV. The identified hadrons are measured in the rapidity regions |y| < 0.5 and 0.5 < |y| < 1.0 for the pT range 2.5 < pT < 10 GeV/c. We observe significant rapidity asymmetry for charged pion

Y. G. Ma

New results on $ϕ$-meson production and elliptic flow $v_{2}$ measurements from RHIC 2004 run (Run-IV) have been reviewed. In addition, the di-hadron correlation function between the trigged $ϕ$ and $Ω$ and the associated soft particles was simulated. Knowledge about these results are discussed.

Luis Martinez Alonso, Elena Medina

A scheme for solving quasiclassical string equations is developped to prove that genus-zero Whitham hierarchies describe the deformations of planar domains determined by rational conformal maps. This property is applied in normal matrix models to show that deformations of simply-connected supports of eigenvalues under changes of coupling constants are govern

A. Iomin

It is shown that the Weyl fractional derivative can quantize an open system. A fractional kicked rotor is studied in the framework of the fractional Schrodinger equation. The system is described by the non-Hermitian Hamiltonian by virtue of the Weyl fractional derivative. Violation of space symmetry leads to acceleration of the orbital momentum. Quantum loca

Xavier Calbet, Ricardo Lopez-Ruiz

The maximum complexity momentum distribution for an isolated monodimensional ideal gas out of equilibrium is derived analytically. In a first approximation, it consists of a double non-overlapping Gaussian distribution. In good agreement with this result, the numerical simulations of a particular isolated monodimensional gas, which is abruptly pushed far fro

Vahagn Nersesyan

In this paper we study the problem of ergodicity for the complex Ginzburg--Landau equation perturbed by an unbounded random kick-force. Randomness is introduced both through the kicks and through the times between the kicks. We show that the Markov process associated with the equation in question possesses a unique stationary distribution and satisfies a pro

Ilia Krasikov, Arie Lev, Bhalchandra D. Thatte

We give upper bounds on the order of the automorphism group of a simple graph

Eric Gautier

We consider stochastic nonlinear Schrodinger equations driven by an additive noise. The noise is fractional in time with Hurst parameter H in (0,1). It is also colored in space and the space correlation operator is assumed to be nuclear. We study the local well-posedness of the equation. Under adequate assumptions on the initial data, the space correlations

Steven Zucker

Let X be a locally symmetric variety. Let EBS(X) and TorE(X) denote its excentric Borel-Serre and excentric toroidal compactifications, resp. We determine their least common modification and use it to prove a conjecture of Goresky and Tai concerning canonical extensions of homogeneous vector bundles. In the process, we see that EBS(X) and TorE(X) are homotop

Ganna Kudryavtseva, Victor Maltcev

We give a monoid presentation in terms of generators and defining relations for the partial analogue of the finite dual inverse symmetric monoid.

Jeff Kiralis

We define two complexes on which the group Aut$(F_n)$ acts freely. The homotopy groups of these are studied. They map to the K-groups of Z and are themselves a sort of pre-K-theory.

Noureddine El Karoui

Estimating the eigenvalues of a population covariance matrix from a sample covariance matrix is a problem of fundamental importance in multivariate statistics; the eigenvalues of covariance matrices play a key role in many widely techniques, in particular in Principal Component Analysis (PCA). In many modern data analysis problems, statisticians are faced wi

Yuri Bahturin, Mikhail Zaicev

In this paper we describe graded automorphisms and antiautomorphisms of finite order on matrix algebras endowed with a group gradings by a finite abelian group over an arbitrary algebraically closed field of charcteristic different from 2.

Seymour Bachmuth

All groups are 2-generator. For any prime-power q, Theorem 1 constructs a solvable matrix group over a quotient of a Laurent polynomial ring. This group is closely related to a group of exponent q as shown in Theorems 2 & 3 . Theorem 4 in section 5 shows that a group of prime-power exponent contains the relations of a solvable group. It follows that the Burn

Michael E. Hoffman

We review the relation between the Hopf algebra QSym of quasi-symmetric functions and the multiple zeta values, and then discuss a commutative diagram involving the Hopf algebra Sym of symmetric functions, the Hopf algebra dual NSym of QSym, and the Hopf algebras of rooted trees and planar rooted trees as defined by Kreimer and Foissy respectively.

Dan Margalit, Steven Spallone

We give a simple explicit construction of pseudo-Anosov mapping classes using an improvement of the homological criterion of Casson-Bleiler.

Jae Choon Cha

We study the group of rational concordance classes of codimension two knots in rational homology spheres. We give a full calculation of its algebraic theory by developing a complete set of new invariants. For computation, we relate these invariants with limiting behaviour of the Artin reciprocity over an infinite tower of number fields and analyze it using t

YanYan Li

We give exposition of a Liouville theorem established in \cite{Li3} which is a novel extension of the classical Liouville theorem for harmonic functions. To illustrate some ideas of the proof of the Liouville theorem, we present a new proof of the classical Liouville theorem for harmonic functions. Applications of the Liouville theorem, as well as that of ea

Frank Oertel, Mark Owen

Consider a financial market in which an agent trades with utility-induced restrictions on wealth. For a utility function which satisfies the condition of reasonable asymptotic elasticity at $-\infty$ we prove that the utility-based super-replication price of an unbounded (but sufficiently integrable) contingent claim is equal to the supremum of its discounte

José Bertin, Fabrice Rosay

We study the deformation theory aspects of Matricial Factorizations, possibly with an orthogonal or symplectic structure. We discuss and extend the Knörrer and Hori-Walcher periodicity theorems

Anton Zorich

This short survey illustrates the ideas of Teichmuller dynamics. As a model application we consider the asymptotic topology of generic geodesics on a &#34;flat&#34; surface and count closed geodesics and saddle connections. This survey is based on the joint papers with A.Eskin and H.Masur and with M.Kontsevich.

Mihai Bostan, Simon Labrunie

We study the permanent regimes of the reduced Vlasov-Maxwell system for laser-plasma interaction. A non-relativistic and two different relativistic models are investigated. We prove the existence of solutions where the distribution function is Boltzmannian and the electromagnetic variables are time-harmonic and circularly polarized.

José A. Carrillo, Simon Labrunie

We analyse a reduced 1D Vlasov--Maxwell system introduced recently in the physical literature for studying laser-plasma interaction. This system can be seen as a standard Vlasov equation in which the field is split in two terms: an electrostatic field obtained from Poisson&#39;s equation and a vector potential term satisfying a nonlinear wave equation. Both

Patrick Ciarlet, Beate Jung, Samir Kaddouri, Simon Labrunie

This paper is the second part of a threefold article, aimed at solving numerically the Poisson problem in three-dimensional prismatic or axisymmetric domains. In the first part of this series, the Fourier Singular Complement Method was introduced and analysed, in prismatic domains. In this second part, the FSCM is studied in axisymmetric domains with conical

Frank Oertel

By investigating in detail discontinuities of the first kind of real-valued functions and the analysis of unordered sums, where the summands are given by values of a positive real-valued function, we develop a measure-theoretical framework which in particular allows us to describe \textit{rigorously} the representation and meaning of sums of jumps of type $\

Patrick Ciarlet, Beate Jung, Samir Kaddouri, Simon Labrunie

This is the first part of a threefold article, aimed at solving numerically the Poisson problem in three-dimensional prismatic or axisymmetric domains. In this first part, the Fourier Singular Complement Method is introduced and analysed, in prismatic domains. In the second part, the FSCM is studied in axisymmetric domains with conical vertices, whereas, in

M. Baake, P. Gritzmann, C. Huck, B. Langfeld

Discrete tomography is a well-established method to investigate finite point sets, in particular finite subsets of periodic systems. Here, we start to develop an efficient approach for the treatment of finite subsets of mathematical quasicrystals. To this end, the class of cyclotomic model sets is introduced, and the corresponding consistency, reconstruction

Anton Zorich

Various problems of geometry, topology and dynamical systems on surfaces as well as some questions concerning one-dimensional dynamical systems lead to the study of closed surfaces endowed with a flat metric with several cone-type singularities. Such flat surfaces are naturally organized into families which appear to be isomorphic to the moduli spaces of hol

Luigi Manca

The dynamic programming approach for the control of a 3D flow governed by the stochastic Navier-Stokes equations for incompressible fluid in a bounded domain is studied. By a compactness argument, existence of solutions for the associated Hamilton-Jacobi-Bellman equation is proved. Finally, existence of an optimal control through the feedback formula and of

A. E. Mironov

We obtain some equations for Hamiltonian-minimal Lagrangian surfaces in CP^2 and give their particular solutions in the case of tori.

Bernhard Lamel, Nordine Mir

Let M be a connected real-analytic hypersurface in N-dimensional complex euclidean space whose Levi form is nondegenerate at some point. We prove that for every point p in M, there exists an integer k=k(M,p) such that germs at p of local real-analytic CR automorphisms of M are uniquely determined by their k-jets (at p). To prove this result we develop a new

Yuli B. Rudyak, Stéphane Sabourau

We prove a finiteness result for the systolic area of groups, answering a question of M. Gromov. Namely, we show that there are only finitely many possible unfree factors of fundamental groups of~2-complexes whose systolic area is uniformly bounded. Furthermore, we prove a uniform systolic inequality for all 2-complexes with unfree fundamental group that imp

Yasuhide Numata

Young&#39;s lattice is a prototypical example of differential posets. Differential posets have the Robinson correspondence, the correspondence between permutations and pairs of standard tableaux with the same shape, as in the case of Young&#39;s lattice. Fomin introduced generalized Schur operators to generalize the method of Robinson correspondence in diffe

Enrique Torres-Giese, Denis Sjerve

We compute the fundamental group of the spaces of ordered commuting $n$-tuples of elements in the Lie groups SU(2), U(2) and SO(3). For SO(3) the computation of the mod-2 cohomology of the components of these spaces is also obtained.

Antonio F. Costa, Sergey Natanzon

Let $Mod_{g}$ be the modular group of surfaces of genus $g$. Each element $[h]\in Mod_{g}$ induces in the integer homology of a surface of genus $g$ a symplectic automorphism $H([h])$ and Poincaré shown that $H:Mod_{g}\to Sp(2g,\mathbb{Z})$ is an epimorphism. The theory of real algebraic curves justify the definition of real Riemann surface as a Riemann surf

John F. Duncan

We study a self-dual N=1 super vertex operator algebra and prove that the full symmetry group is Conway&#39;s largest sporadic simple group. We verify a uniqueness result which is analogous to that conjectured to characterize the Moonshine vertex operator algebra. The action of the automorphism group is sufficiently transparent that one can derive explicit e

M. P. Kozlovskii, I. V. Pylyuk, O. O. Prytula

The description of a three-dimensional Ising-like magnet in the presence of an external field in the vicinity of the critical point by the collective variables method is proposed. Using the renormalization group transformations, the scaling region size is defined as a function of temperature and field. The obtained expressions for the free energy, equation o

M. Consoli

The phenomenon of spontaneous symmetry breaking admits a physical interpretation in terms of the Bose-condensation process of elementary spinless quanta. In a cutoff theory, this leads to a picture of the vacuum as a condensed medium whose excitations might deviate from exact Lorentz covariance in both the ultraviolet and infrared regions. For this reason, t

C. Bogdanos, K. Tamvakis

We consider the cosmological evolution of a brane for general bulk matter content. In our setup the bulk pressure and the energy exchange densities are comparable to the brane energy density. Adopting a phenomenological fluid ansatz and generalizations of it, we derive a set of exact solutions of the Friedmann equation that exhibit accelerated expansion. We

Hongbo Cheng

The Casimir effect for parallel plates in the presence of compactified universal extra dimensions within the frame of Kaluza-Klein theory is analyzed. Having regularized and discussed the expressions of Casimir force in the limit, we show that the nature of Casimir force is repulsive if the distance between the plates is large enough and the higher-dimension

R. Holman, L. Mersini-Houghton

In previous work, we showed that the answer to the question posed in the title cannot be found within an equilibrium setting. The inclusion of {\em dynamical} backreaction effects from massive long wavelength modes on the initial DeSitter patches results in gravitational instabilities that cleanse the phase space of inflationary initial conditions of all reg

A. Sherstnev

A brief review of theoretical and experimental aspects of $b$-quark production measurements at the LHC.

Steven Abel, Veronique Page

We discuss how Dirac neutrinos can naturally be generated in supersymmetry and how they allow for an Affleck-Dine leptogenesis scenario, in which a left-right asymmetry is generated in the sneutrino sector, the left part of which is transferred to a baryon asymmetry via sphaleron transitions. No exotic fields need to be added to the MSSM other than the right

Antonio Pich

Precise measurements of the tau lepton properties provide stringent tests of the Standard Model structure and accurate determinations of its parameters. We overview the present status of a few selected topics: lepton universality, QCD tests and the determination of alpha_s, m_s and V_us from hadronic tau decays, and lepton flavor violation phenomena.

A. D. Polosa

The molecule and the tetraquark model are the two competing interpretations of the X(3872). I will briefly comment on how far these two pictures are really resolvable by the experiment, and I will give a concise account on a new method for defining the quark content of hadrons at heavy-ion colliders.

C. Hanhart

Although studied for many years the nature of the light scalar mesons remains controversial. Here we shall present a method, applicable for s-wave states located close to a threshold, that allows one to quantify the molecular part of a given state. When applied to the $f_0(980)$ a dominance of the molecular component is found. In the second part we show that

Yu. P. Goncharov

The estimates of parameters for the classical SU(3)-gluonic field responsible for linear confinement are given for pions and kaons. Also estimates for the characteristics of the mentioned field such as gluon concentrations, electric and magnetic colour field strengths are adduced along with those for quark velocities in mesons under discussion. Possible conn

Fulvia De Fazio

We analyze the exclusive rare $B \to K^{(*)} \ell^+ \ell^-$, $B \to K^{(*)} ν\bar ν$ and $B \to K^* γ$ decays in the Applequist-Cheng-Dobrescu model, an extension of the Standard Model in presence of universal extra dimensions. In the case of a single universal extra dimension, we study the dependence of several observables on the compactification parameter

Shrirang S. Deshingkar

We propose a new scheme for extracting gravitational radiation from a characteristic numerical simulation of a spacetime. This method is similar in conception to our earlier work but analytical and numerical implementation is different. The scheme is based on direct transformation to the Bondi coordinates and the gravitational waves are extracted by calculat

Mayeul Arminjon

We investigate the possibility of extending Newton&#39;s second law to the general framework of theories in which special relativity is locally valid, and in which gravitation changes the flat Galilean space-time metric into a curved metric. This framework is first recalled, underlining the possibility to uniquely define a space metric and a local time in an

Stefano Ansoldi, Eduardo I. Guendelman

Cosmology is usually understood as an observational science, where experimentation plays no role. It is interesting, nevertheless, to change this perspective addressing the following question: what should we do to create a universe, in a laboratory? It appears, in fact, that this is, in principle, possible according to at least two different paradigms; both

C. T. Hoang, J. Sawada, X. Shu

A polynomial time algorithm that determines for a fixed integer k whether or not a P5-free graph can be k-colored is presented in this paper. If such a coloring exists, the algorithm will produce a valid k-coloring.

Tom Chou

We consider the linear stability of two inviscid fluids, in the presence of gravity, sheared past each other and separated by an flexible plate. Conditions for exponential growth of velocity perturbations are found as functions of the flexural rigidity of the plate and the shear rate. This Kelvin-Helmholtz instability is then analysed in the presence of plat

Gabriel Tellez

We derive the exact general form of the equation of state, in the fugacity format, for the two-dimensional Coulomb gas. Our results are valid in the conducting phase of the Coulomb gas, for temperatures above the Kosterlitz-Thouless transition. The derivation of the equation of state is based on the knowledge of the general form of the short-distance expansi

Ting Lu, Rachel Wortis

We calculate the rate of transverse relaxation arising from vortex motion in the mixed state of YBa_2Cu_3O_7 with the static field applied along the c axis. The vortex dynamics are described by an overdamped Langevin equation with a harmonic elastic free energy. We find that the variation of the relaxation with temperature, average magnetic field, and local

Q. Bian, S. K. Bose, R. C. Shukla

By employing the analytic embedded-atom potentials of Mei {\it et al.} [Phys. Rev. B 43, 4653 (1991)] we have calculated the phonon dispersion spectra for six fcc metals: Cu, Ag, Au, Ni, Pd and Pt. We have also investigated thermal properties of these metals within the quasiharmonic approximation. Results for the lattice constants, coefficients of linear the

V. Mlinar, F. M. Peeters

Using 3D k.p calculation including strain and piezoelectricity we predict variation of electronic and optical properties of InAs/GaAs quantum dots (QDs) with the substrate orientation. The QD transition energies are obtained for high index substrates [11k], where k = 1,2,3 and are compared with [001]. We find that the QD size in the growth direction determin

R. I. Dzhioev, V. L. Korenev, M. V. Lazarev, V. F. Sapega

We report a giant electric field induced increase of spin orientation of excitons in n-type GaAs/AlGaAs quantum well. It correlates strongly with the formation of negatively charged excitons (trions) in the photoluminescence spectra. Under resonant excitation of neutral heavy-hole excitons, the polarization of excitons and trions increases dramatically with

T. Lorenz, S. Stark, O. Heyer, N. Hollmann

We present thermal expansion alpha, magnetostriction and specific heat C measurements of \tal, which shows a quantum phase transition from a spin-gap phase to a Neel-ordered ground state as a function of magnetic field around H_{C0}->4.8T. Using Ehrenfest&#39;s relation, we find huge pressure dependencies of the spin gap for uniaxial as well as for hydrostat

P. Chandra, P. B. Littlewood

In this review, we hope to give the reader a self-contained contemporary presentation of the application of Landau theory to ferroelectrics. We begin by developing Landau theory for homogenous bulk ferroelectrics and then consider the finite-size (thin film) case within the related Landau-Ginzburg approach. Next we discuss the treatment of inhomogeneity with

Gao Xianlong, M. Rizzi, Marco Polini, Rosario Fazio

The Luther-Emery liquid is a state of matter that is predicted to occur in one-dimensional systems of interacting fermions and is characterized by a gapless charge spectrum and a gapped spin spectrum. In this Letter we discuss a realization of the Luther-Emery phase in a trapped cold-atom gas. We study by means of the density-matrix renormalization-group tec

A. A. Burlakov, V. L. Gurtovoi, S. V. Dubonos, A. V. Nikulov

Multiple and single measurements of quantum states of mesoscopic superconducting loops are carried out in order to investigate a possibility of macroscopic quantum superposition and of creation of a superconductor quantum register. Asymmetric superconducting rings are used in order to be convinced that single measurement gives result corresponding to one of

Chengshi Liu

As the most fundamental empirical law, Zipf&#39;s law has been studied from many aspects. But its meaning is still an open problem. Some models have been constructed to explain Zipf&#39;s law. In the letter, a new concept named nonsymmetric entropy was introduced, maximizing nonsymmetric entropy leads naturally to Zipf&#39;s law.

S. Autier-Laurent, B. Mercey, D. Chippaux, P. Limelette

V2O3 thin films about 10 nm thick were grown on Al2O3 (0001) by pulsed laser deposition. The XRD analysis is in agreement with R-3c space group. Some of them exhibit the metal / insulator transition characteristic of V2O3 bulk material and others samples exhibit a metallic behavior. For the latter, the XPS analysis indicates an oxidation state of +III for va

E. K. Dahl, A. Sudbo

We derive a Ginzburg-Landau free energy for a p-wave ferromagnetic superconductor. The starting point is a microscopic Hamiltonian including a spin generalised BCS term and a Heisenberg exchange term. We find that coexistence of magnetisation and superconductivity depends on the sign of the energy-gradient of the DOS at Fermi level. We also compute the tunne

Jong Soo Lim, Mahn-Soo Choi

We have studied the Kondo quantum dot coupled to two superconducting leads and investigated the subgap Andreev states using the NRG method. Contrary to the recent NCA results [Clerk and Ambegaokar, Phys. Rev. B 61, 9109 (2000); Sellier et al., Phys. Rev. B 72, 174502 (2005)], we observe Andreev states both below and above the Fermi level.

P. M. Ostrovsky, Ya. V. Fominov, M. V. Feigel&#39;man

We consider a small metallic grain coupled to a superconductor by a tunnel contact. We study the interplay between proximity and charging effects in the presence of the external magnetic field. Employing the adiabatic approximation we develop a self-consistent theory valid for an arbitrary ratio of proximity and Coulomb strength. The magnetic field suppresse

San-Huang Ke, Weitao Yang, Harold U. Baranger

We address the quality of electrical contact between carbon nanotubes and metallic electrodes by performing first-principles calculations for the electron transmission through ideal 2- and 3-terminal junctions, thus revealing the physical limit of tube-metal conduction. The structural model constructed involves surrounding the tube by the metal atoms of the

C. A. Stafford, F. Kassubek, J. Bürki, H. Grabert

The conducting and thermodynamic properties of ballistic metallic nanocontacts with smooth shapes are investigated. All properties are related to the electronic scattering matrix, which is evaluated in the WKB approximation for independent electrons and in the self-consistent Hartree approximation for interacting electrons. Mesoscopic oscillations of order 1

Thomas W. J. Thompson, John A. Tomsick, J. J. M. in &#39;t Zand, Richard E. Rothschild

With recent and archival Rossi X-Ray Timing Explorer (RXTE) X-ray measurements of the heavily obscured X-ray pulsar EXO 1722-363 (IGR J17252-3616), we carried out a pulse timing analysis to determine the orbital solution for the first time. The binary system is characterized by a_x sin(i) = 101 +/- 3 lt-s and P_orb = 9.7403 +/- 0.0004 days (90% confidence),

A. I. D. Hoffmann, D. Horns, A. Santangelo

Amongst the sources seen in very high gamma-rays several are associated with Pulsar Wind Nebulae (``TeV plerions&#39;&#39;). The study of hard X-ray/soft gamma-ray emission is providing an important insight into the energetic particle population present in these objects. The unpulsed emission from pulsar/pulsar wind nebula systems in the energy range accessi

Nathan Smith

I discuss the role of short-duration eruptive mass loss in the evolution of very massive stars. Giant eruptions of Luminous Blue Variables (LBVs) like the 19th century event of $η$ Carinae can remove large quantities of mass almost instantaneously, making them significant in stellar evolution. They can potentially remove more mass from the star than line-dri

E. Rosolowsky

We present Berkeley Illinois Maryland Association (BIMA) millimeter interferometer observations of giant molecular clouds (GMCs) along a spiral arm in M31. The observations consist of a survey using the compact configuration of the interferometer and follow-up, higher-resolution observations on a subset of the detections in the survey. The data are processed