May 2006 arXiv papers — page 31

H. Bombin, M. A. Martin-Delgado

We prove several theorems characterizing the existence of homological error correction codes both classically and quantumly. Not every classical code is homological, but we find a family of classical homological codes saturating the Hamming bound. In the quantum case, we show that for non-orientable surfaces it is impossible to construct homological codes ba

Christopher E. Kuklewicz, Franco N. C. Wong, Jeffrey H. Shapiro

We have generated a new type of biphoton state by cavity-enhanced down-conversion in a type-II phase-matched, periodically-poled KTiOPO_4 (PPKTP) crystal. By introducing a weak intracavity birefringence, the polarization-entangled output was modulated between the singlet and triplet states according to the arrival-time difference of the signal and idler phot

Benedetto Militello, Paolo Aniello, Antonino Messina

A novel perturbative treatment of the time evolution operator of a quantum system is applied to the model describing a Raman-driven trapped ion in order to obtain a suitable 'effective model'. It is shown that the associated effective Hamiltonian describes the system dynamics up to a certain transformation which may be interpreted as a 'dynamical

M. Combescure

The study of Mutually Unbiased Bases continues to be developed vigorously, and presents several challenges in the Quantum Information Theory. Two orthonormal bases in $\mathbb C^d, B {and} B'$ are said mutually unbiased if $\forall b\in B, b'\in B'$ the scalar product $b\cdot b'$ has modulus $d^{-1/2}$. In particular this property has been in

J. S. Neergaard-Nielsen, B. Melholt Nielsen, C. Hettich, K. Moelmer

We report on the experimental observation of quantum-network-compatible light described by a non-positive Wigner function. The state is generated by photon subtraction from a squeezed vacuum state produced by a continuous wave optical parametric amplifier. Ideally, the state is a coherent superposition of odd photon number states, closely resembling a superp

Yapeng Hu, Weigang Qiu, Hongbao Zhang

This paper revisits the quantum mechanics for one photon from the modern viewpoint and by the geometrical method. Especially, besides the ordinary (rectangular) momentum representation, we provide an explicit derivation for the other two important representations, called the cylindrically symmetrical representation and the spherically symmetrical representat

Babak Shahbaba, Radford M. Neal

We investigate the application of hierarchical classification schemes to the annotation of gene function based on several characteristics of protein sequences including phylogenic descriptors, sequence based attributes, and predicted secondary structure. We discuss three Bayesian models and compare their performance in terms of predictive accuracy. These mod

T. Wibig, K. Kolodziejczak, R. Pierzynski, R. Sobczak

A group of high school students (XII Liceum) in the framework of the Roland Maze Project has built a compact telescope of three Geiger-Muller counters. The connection between the telescope and PC computer was also created and programed by students involved in the Project. This has allowed students to use their equipment to perform serious scientific measurem

T. Bountis, Ch. Skokos

Space charge effects can be very important for the dynamics of intense particle beams, as they repeatedly pass through nonlinear focusing elements, aiming to maximize the beam's luminosity properties in the storage rings of a high energy accelerator. In the case of hadron beams, whose charge distribution can be considered as "frozen" within a cyl

Weixing Shu, Hailu Luo, Fei Li, Zhongzhou Ren

We investigate the reflection and refraction behaviors of electromagnetic waves at the interface between an isotropic material and the anisotropic medium with a unique dispersion relation. We show that the refraction angle of whether phase or energy flow for $E$-polarized waves is opposite to that for $H$-polarized waves, though the dispersion relations for

A. Galoyan, J. Ritman, V. Uzhinsky

Patches to the code of the Ultra-relativisic Quantum Molecular Dynamics model (UrQMD version 1.3) are described. They improve the code operation. The most important one is done for the file ANNDEC.F.

Bao-Xi Sun, Xiao-Fu Lu, Lei Li, Ping-Zhi Ning

According to Wick's theorem, the second order self-energy corrections of hadrons in the hot and dense nuclear matter are calculated. Furthermore, the Feynman rules are summarized, and an effective formulation on quantum hadrodynamics at finite temperatures and densities is evaluated. As the strong couplings between nucleons are considered, the self-consi

P. Bourgeois, Y. Sato, J. Shaw, R. Alarcon

The mean square polarizability radii of the proton have been measured for the first time in a virtual Compton scattering experiment performed at the MIT-Bates out-of-plane scattering facility. Response functions and polarizabilities obtained from a dispersion analysis of the data at Q2=0.06 GeV2/c2 are in agreement with O(p3) heavy baryon chiral perturbation

A. Marinov, I. Rodushkin, Y. Kashiv, L. Halicz

Evidence for the existence of long-lived neutron-deficient isotopes has been found in a study of naturally-occurring Th using iductively coupled plasma-sector field mass spectrometry. They are interpreted as belonging to the recently discovered class of long-lived high spin super- and hyperdeformed isomers.

NA60 Collaboration, R. Arnaldi

We report on a precision measurement of low-mass muon pairs in 158 AGeV indium-indium collisions at the CERN SPS. A significant excess of pairs is observed above the yield expected from neutral meson decays. The unprecedented sample size of 360 000 dimuons and the good mass resolution of about 2% allow us to isolate the excess by subtraction of the decay sou

Jose-Luis Lopez, Ricardo Lopez-Ruiz

Liénard equations of the form $\ddot{x}+εf(x)\dot{x}+x=0$, with $f(x)$ an even function, are considered in the weakly nonlinear regime ($ε\to 0$). A perturbative algorithm for obtaining the number, amplitude and shape of the limit cycles of these systems is given. The validity of this algorithm is shown and several examples illustrating its application are g

V. E. Vekslerchik

The derivation of the Backlund transformations (BTs) is a standard problem of the theory of the integrable systems. Here, I discuss the equations describing the BTs for the Ablowitz-Ladik hierarchy (ALH), which have been already obtained by several authors. The main aim of this work is to solve these equations. This can be done in the framework of the so-cal

Marcel Ausloos, Andrzej Pekalski

A simple computer simulation model of a closed market on a fixed network with free flow of goods and money is introduced. The model contains only two variables : the amount of goods and money beside the size of the system. An initially flat distribution of both variables is presupposed. We show that under completely random rules, i.e. through the choice of i

G Ambika, K Ambika

In this work we consider two models of two dimensional discrete systems subjected to three different types of coupling and analyse systematically the performance of each in realising synchronised states.We find that linear coupling effectively introduce control of chaos along with synchronisation,while synchronised chaotic states are possible with an additiv

Emmanuelle Gouillart, Jean-Luc Thiffeault, Matthew D. Finn

Topological chaos relies on the periodic motion of obstacles in a two-dimensional flow in order to form nontrivial braids. This motion generates exponential stretching of material lines, and hence efficient mixing. Boyland et al. [P. L. Boyland, H. Aref, and M. A. Stremler, J. Fluid Mech. 403, 277 (2000)] have studied a specific periodic motion of rods that

Domenico Finco, Kenji Yajima

In this paper we consider the wave operators $W_{\pm}$ for a Schrödinger operator $H$ in ${\bf{R}}^n$ with $n\geq 4$ even and we discuss the $L^p$ boundedness of $W_{\pm}$ assuming a suitable decay at infinity of the potential $V$. The analysis heavily depends on the singularities of the resolvent for small energy, that is if 0-energy eigenstates exist. If s

Rafal Kulik

In this paper we establish the Bahadur-Kiefer representation for sample quantiles of GARCH sequences with optimal rates.

Ignacio Guerra

Consider the problem \begin{eqnarray*} -Δu_\e &=& v_\e^p \quad v_\e>0\quad {in}\quad Ω, -Δv_\e &=& u_\e^{q_\e}\quad u_\e>0\quad {in}\quad Ω, u_\e&=&v_\e\:\:=\:\:0 \quad {on}\quad \partial Ω, \end{eqnarray*} where $Ω$ is a bounded convex domain in $\R^N,$ $N>2,$ with smooth boundary $\partial Ω.$ Here $p,q_\e>0,$ and \begin{equation*} ε:=\frac{N}{p+1}+\frac{N

Douglas Lundholm

In this Master of Science Thesis I introduce geometric algebra both from the traditional geometric setting of vector spaces, and also from a more combinatorial view which simplifies common relations and operations. This view enables us to define Clifford algebras with scalars in arbitrary rings and provides new suggestions for an infinite-dimensional approac

Erick Herbin, Ely Merzbach

We define and study the multiparameter fractional Brownian motion. This process is a generalization of both the classical fractional Brownian motion and the multiparameter Brownian motion, when the condition of independence is relaxed. Relations with the Lévy fractional Brownian motion and with the fractional Brownian sheet are discussed. Different notions o

Brendan Hassett, Yuri Tschinkel

This paper addresses weak approximation for rationally connected varieties defined over the function field of a curve, especially at places of bad reduction. Our approach entails analyzing the rational connectivity of the smooth locus of singular reductions of the variety. As an application, we prove weak approximation for cubic surfaces with square-free dis

Alex Furman

We consider the problems of measurable isomorphisms and joinings, measurable centralizers and quotients for certain classes of ergodic group actions on infinite measure spaces. Our main focus is on systems of algebraic origin: actions of lattices and other discrete subgroups on homogeneous spaces G/H where H is a sufficiently rich unimodular subgroup in a se

J. M. Aldaz, J. Pérez Lázaro

We characterize the space $BV(I)$ of functions of bounded variation on an arbitrary interval $I\subset \mathbb{R}$, in terms of a uniform boundedness condition satisfied by the local uncentered maximal operator $M_R$ from $BV(I)$ into the Sobolev space $W^{1,1}(I)$. By restriction, the corresponding characterization holds for $W^{1,1}(I)$. We also show that

Nabil L. Youssef

Adopting the global approach to tangent bundles of order two established in[1], we develop this approach to find new results. We also generalize various results of [3], [4] and [6] to the geometry of tangent bundles of order two.

Evgenij Esyp, Ilya Kazachkov

In this paper we construct a gathering process by the means of which we obtain new normal forms in braid groups. The new normal forms generalise Artin-Markoff normal forms and possess an extremely natural geometric description. In the two last sections of the paper we discuss the implementation of the introduced gathering process and the questions that arose

Paul Norbury

A topological invariant of a polynomial map $p:X\to B$ from a complex surface containing a curve $C\subset X$ to a one-dimensional base is given by a rational second homology class in the compactification of the moduli space of genus $g$ curves with $n$ labeled points $\modmgn$. Here the generic fibre of $p$ has genus $g$ and intersects $C$ in $n$ points. In

Norikazu Yamaguchi

In this paper we study the initial-boundary value problem for the magnetohydrodynamic system in three dimensional exterior domain. We show an existence theorem of global in time strong solution for small initial data and we also show its asymptotic behavior when time goes to infinity.

Adrian Riskin

We calculate the outerplanar crossing numbers of complete multipartite graphs which have $n$ partite sets with $m$ vertices and one partite set with $p$ vertices, where either $p|mn$ or $mn|p$.

Didier Chauveau, Pierre Vandekerkhove

In MCMC methods, such as the Metropolis-Hastings (MH) algorithm, the Gibbs sampler, or recent adaptive methods, many different strategies can be proposed, often associated in practice to unknown rates of convergence. In this paper we propose a simulation-based methodology to compare these rates of convergence, grounded on an entropy criterion computed from p

F. Hivert, J. -C. Novelli, J. -Y. Thibon

We propose several constructions of commutative or cocommutative Hopf algebras based on various combinatorial structures, and investigate the relations between them. A commutative Hopf algebra of permutations is obtained by a general construction based on graphs, and its non-commutative dual is realized in three different ways, in particular as the Grossman-

Atanas Iliev, Laurent Manivel

We show that the family of 21-dimensional intermediate jacobians of cubic fivefolds containing a given cubic fourfold X is generically an algebraic integrable system. In the proof we apply an integrability criterion, introduced and used by Donagi and Markman to find a similar integrable system over the family of cubic threefolds in X. To enter in the conditi

K. Leśniak

We present the set of axioms for topological space with the operation of boundary as primitive notion.

Ingrid Bauer, Fabrizio Catanese, Fritz Grunewald

We start discussing the group of automorphisms of the field of complex numbers, and describe, in the special case of polynomials with only two critical values, Grothendieck's program of 'Dessins d' enfants', aiming at giving representations of the absolute Galois group. We describe Chebycheff and Belyi polynomials, and other explicit examples

Peter Zograf

We propose a universal approach to a range of enumeration problems in graphs. The key point is in contracting suitably chosen symmetric tensors placed at the vertices of a graph along the edges. In particular, this leads to an algorithm that counts the number of d-regular subgraphs of an arbitrary graph including the number of d-factors (previously we consid

Tian Khoon Lim

This thesis concerns the study of homogeneous factorisations of complete graphs with edge-transitive factors. A factorisation of a complete graph $K_n$ is a partition of its edges into disjoint classes. Each class of edges in a factorisation of $K_n$ corresponds to a spanning subgraph called a factor. If all the factors are isomorphic to one another, then a

Uffe Haagerup, Hanne Schultz

In this paper we generalize Brown's spectral distribution measure to a large class of unbounded operators affiliated with a finite von Neumann algebra. Moreover, we compute the Brown measure of all unbounded R-diagonal operators in this class. As a particular case, we determine the Brown measure of z=xy^{-1}, where (x,y) is a circular system in the sense

Melanie Guenais, Francois Parreau

Given an irrational rotation $T$ on $\M T$ we settle necessary and sufficient conditions on a step function $ϕ$ and $t\in \M T$ for the existence of measurable solutions to the cohomogical equation $$\exp{(2iπϕ)}=\e{2iπt}f/f\rond T.$$ This yields a characterization of eigenvalues and eigenfunctions for several transformations arising from irrational rotation

Ilya Kazachkov

This is a survey paper on Alegbraic Geometry over Lie Algebras

Daniel Fish

In this note we discuss conditions under which a linear connection on a manifold equipped with both a symmetric (Riemannian) and a skew-symmetric (almost-symplectic or Poisson) tensor field will preserve both structures.

L. Sunil Chandran, Naveen Sivadasan

For a graph $G$, its \emph{cubicity} $cub(G)$ is the minimum dimension $k$ such that $G$ is representable as the intersection graph of (axis--parallel) cubes in $k$--dimensional space. Chandran, Mannino and Oriolo showed that for a $d$--dimensional hypercube $H_d$, $\frac{d-1}{\log d} \le cub(H_d) \le 2d$. In this paper, we show that $cub(H_d) = Θ(\frac{d}{\

Peter Constantin, Charles Fefferman, Edriss Titi, Arghir Zarnescu

We consider systems of particles coupled with fluids. The particles are described by the evolution of their density, and the fluid is described by the Navier-Stokes equations. The particles add stress to the fluid and the fluid carries and deforms the particles. Because the particles perform rapid random motion, we assume that the density of particles is car

Simona Settepanella

Consider the ring R:=\Q[τ,τ^{-1}] of Laurent polynomials in the variable τ. The Artin's Pure Braid Groups (or Generalized Pure Braid Groups) act over R, where the action of every standard generator is the multiplication by τ. In this paper we consider the cohomology of these groups with coefficients in the module R (it is well known that such cohomology

Bogdan Ion

We show how a certain limit of the nonsymmetric Macdonald polynomials appears in the representation theory of semisimple groups over p--adic fields as matrix coefficients for the unramified principal series representations. The result is the nonsymmetric counterpart of a classical result relating the same limit of the symmetric Macdonald polynomials to zonal

V. Hankele, G. Klamke, D. Zeppenfeld

Azimuthal angle correlations of the jets in Hjj events at the LHC provide a probe of the CP nature of Higgs couplings to gauge bosons. In weak boson fusion the HWW and HZZ couplings are tested. Gluon fusion processes probe the tensor structure of the effective Hgg vertex and thus the CP nature of the dominant quark couplings.

A. V. Kuznetsov, N. V. Mikheev

The process of neutrino propagation through an active medium consisting of magnetic field and plasma is analysed. We consider in detail the contribution of a magnetic field B into the neutrino self-energy operator Sigma (p). The results for this contribution were contradictory in the previous literature. For the conditions of the early universe where the bac

Gabriela Barenboim

We present a new approach to quintessential inflation, in which both dark energy and inflation are explained by the evolution of a single scalar field. We start from a simple scalar potential with both oscillatory and exponential behavior.We employ the conventional reheating mechanism of new inflation, in which the scalar decays to light fermions with a deca

M. Beccaria, G. Macorini, F. M. Renard, C. Verzegnassi

We compute the complete electroweak one-loop effect on the process of $t$-channel single top production at LHC in the Standard Model and in the MSSM within the mSUGRA symmetry breaking scheme. We find that the one-loop electroweak SM effect is large, and decreases the cross section of an amount that is of the same size as that of the NLO QCD one. The genuine

Yongseok Oh, Hungchong Kim

We propose that the scalar $κ(800)$ meson may play an important role in $K^*$ photoproduction. In the reactions of $γp \to K^{*+} Λ$ and $γp \to K^{*0} Σ^+$, we consider the production mechanisms including $t$-channel $K^*$, $K$, $κ$ exchanges, s-channel $N$, $Δ$ diagrams, and $u$-channel $Λ$, $Σ$, $Σ^*$ diagrams within the tree level approximation, and find

M. E. Bracco, F. S. Navarra, M. Nielsen

This paper has been withdrawn by the authors. We have discovered an error in the evaluation of the diagram, which invalidates our conclusion.

Thomas G. Rizzo

We examine the properties of TeV-scale extra dimensional black holes (BH) in Randall-Sundrum-like models with Gauss-Bonnet higher-curvature terms present in the action. These theories naturally lead to a mass threshold for BH production in TeV particle collisions which could be observable at LHC/ILC. The lifetimes of such BH are examined and, in particular,

D. Becirevic, Ph. Boucaud, V. Lubicz, G. Martinelli

It has been shown that in the twisted mass formulation of Lattice QCD at maximal twist large cutoff effects are generated when the quark mass becomes of O(a Lambda_QCD^2). In general, these effects can be suppressed in two ways: either by choosing the critical quark mass in an "optimal way", or by adding the Clover term to the twisted action. We inve

F. Hubaut

The new CERN proton-proton collider, the LHC, is about to start in 2007 its data taking. Millions of top quarks will be available out of these data, allowing to perform a wide range of precision measurements and searches for new physics. An overview of the planned top physics program accessible with ttbar events is given for the ATLAS and CMS experiments. A

Patrick Peter, Emanuel J. C. Pinho, Nelson Pinto-Neto

We discuss the gravitational wave background produced by bouncing models based on a full quantum evolution of a universe filled with a perfect fluid. Using an ontological interpretation for the background wave function allows us to solve the mode equations for the tensorial perturbations, and we find the spectral index as a function of the fluid equation of

Giampiero Esposito

Our review is devoted to three promising research lines in quantum cosmology and the physics of the early universe. The nonperturbative renormalization programme is making encouraging progress that we here assess from the point of view of cosmological applications: Lagrangian and Hamiltonian form of pure gravity with variable G and Lambda; power-law inflatio

JA Valiente Kroon

We discuss the existence of asymptotically Euclidean initial data sets to the vacuum Einstein field equations which would give rise (modulo an existence result for the evolution equations near spatial infinity) to developments with a past and a future null infinity of different smoothness. For simplicity, the analysis is restricted to the class of conformall

M. Sharif, Sehar Aziz

In this paper we provide a classification of plane symmetric kinematic self-similar perfect fluid and dust solutions. In the perfect fluid and dust cases, kinematic self-similar vectors for the tilted, orthogonal and parallel cases have been explored in the first, second, zeroth and infinite kinds with different equations of state. We obtain total of eleven

R. N. Mohan

In this paper we have discussed different possible orthogonalities in matrices, namely orthogonal, quasi-orthogonal, semi-orthogonal and non-orthogonal matrices including completely positive matrices, while giving some of their constructions besides studying some of their properties.

Tomoko Kita, Rui Sakano, Takuma Ohashi, Sei-ichiro Suga

We study the three-orbital Kondo effect in quantum dot (QD) systems by applying the non-crossing approximation to the three-orbital Anderson impurity model. By investigating the tunneling conductance through a QD, we show that the competition between the Hund-coupling and the orbital level-splitting gives rise to characteristic behavior in transport properti

Bakhtiyor B. Baizakov, Boris A. Malomed, Mario Salerno

We investigate two-dimensional (2D) states of Bose-Einstein condensates (BEC) with self-attraction or self-repulsion, trapped in an axially symmetric optical-lattice potential periodic along the radius. Unlike previously studied 2D models with Bessel lattices, no localized states exist in the linear limit of the present model, hence all localized states are

Julien Robert, Virginie Simonet, Benjamin Canals, Rafik Ballou

The Nd-langasite compound contains planes of magnetic Nd3+ ions on a lattice topologically equivalent to a kagomé net. The magnetic susceptibility does not reveal any signature of long-range ordering down to 2 K but rather a correlated paramagnetism with significant antiferromagnetic interactions between the Nd and a single-ion anisotropy due to crystal fiel

Monica A. Garcia-Nustes, Leonardo Trujillo, Jorge A. Gonzalez

In this work we present a model for computation of random processes in digital computers which solves the problem of periodic sequences and hidden errors produced by correlations. We show that systems with non-invertible non-linearities can produce unpredictable sequences of independent random numbers. We illustrate our result with some numerical calculation

Alexey Yamilov, Hui Cao

Introduction of optical gain to a disordered system results in enhanced fluctuations [$F_{(2)}=var(\tilde{g})/< \tilde{g} >^2$] of dimensionless conductance $\tilde{g}$, similar to the effect of Anderson localization in passive medium. Using numerical simulations we demonstrate that despite of such qualitative similarity, the whole distribution of conductanc

Xiaolin Shi, Lada A. Adamic, Martin J. Strauss

Social networks transmitting covert or sensitive information cannot use all ties for this purpose. Rather, they can only use a subset of ties that are strong enough to be ``trusted&#39;&#39;. In this paper we consider transitivity as evidence of strong ties, requiring that each tie can only be used if the individuals on either end also share at least one oth

Subhro Bhattacharjee, Vijay B. Shenoy, T. Senthil

We explore the possibility that the spin-1 triangular lattice magnet NiGa2 S4 may have a ferro-nematic ground state with no frozen magnetic moment but a uniform quadrupole moment. Such a state may be stabilized by biquadratic spin interactions. We describe the physical properties of this state and suggest experiments to help verify this proposal. We also con

I. Rabuffo, M. T. Mercaldo, L. De Cesare, A. Caramico D&#39;Auria

The field-induced quantum criticality of compounds with ferromagnetically coupled structural spin units (as dimers and ladders) is explored by applying Wilson&#39;s renormalization group framework to an appropriate effective action. We determine the low-temperature phase boundary and the behavior of relevant quantities decreasing the temperature with the app

B. N. J. Persson

When a rubber block is sliding on a hard rough substrate, the substrate asperities will exert time-dependent deformations of the rubber surface resulting in viscoelastic energy dissipation in the rubber, which gives a contribution to the sliding friction. Most surfaces of solids have roughness on many different length scales, and when calculating the frictio

L. Pezze&#39;, A. Smerzi, G. P. Berman, A. R. Bishop

A beam splitter is an important component of an atomic/optical Mach-Zehnder interferometer. Here we study a Bose Einstein Condensate beam splitter, realized with a double well potential of tunable height. We analyze how the sensitivity of a Mach Zehnder interferometer is degraded by the non-linear particle-particle interaction during the splitting dynamics.

M. H. Ghatee, M. Bahadori

Analytical equations of state are presented for fluid mercury in metal, nonmetal, and in metal-nonmetal transition states. Equations of state for metal and nonmetal states are simple in form but the complexities of transition state leads to a complex fourth-order equation. The interatomic potential function used to describe the metal state have a hard repuls

M. H. Ghatee, M. Bahadori

This paper investigates to identify phase transitions in condensed liquid cesium metal by considering the variation of intermolecular potential parameters εand r_m in the whole liquid range, with εbeing the potential well-depth and r_m the position of minimum potential. These parameters were obtained from the parameters of a new equation of state that was de

Mikihito Takenaka, Tsutomu Wakada, Satoshi Akasaka, Shotaro Nishitsuji

For the first time a Fddd network structure is found in a poly(styrene-b-isoprene) (S-I) diblock copolymer melts by using small-angle X-ray scattering and transmission electron microscope, as predicted by Tyler et al. by using calculations with self-consistent field theory for diblock copolymer melts. The phase diagram of the S-I exhibits the sequence of Dis

Ki-Seok Kim, Jung Hoon Han

The slave-rotor mean-field theory of Florens and Georges is generalized to the antiferromagnetic phase of the Hubbard model. An effective action consisting of a spin rotor and a fermion is derived and the corresponding saddle-point action is analyzed. Zero-temperature phase diagram of the antiferromagnetic Hubbard model is presented. While the magnetic phase

D. A. Bagrets, Y. Utsumi, D. S. Golubev, G. Schoen

In order to fully characterize the noise associated with electron transport, with its severe consequences for solid-state quantum information systems, the theory of full counting statistics has been developed. It accounts for correlation effects associated with the statistics and effects of entanglement, but it remains a non-trivial task to account for inter

I. A. Shelykh, N. G. Galkin, N. T. Bagraev

We analyze the conductance of the quantum point contact containing large localized spin J. The additional plateau is formed on a ballistic conductance staircase if only one propagating channel is rendered conducting. The conductance value at this plateau is shown to depend strongly on J and decrease from 3e^2/2h to e^2/h when J increases from 1/2 to infinity

Josselin Garnier, Fatkhulla Abdullaev

The transmissions of matter wave solitons through linear and nonlinear inhomogeneities induced by the spatial variations of the trap and the scattering length in Bose-Einstein condensates are investigated. New phenomena, such as the enhanced transmission of a soliton through a linear trap by a modulation of the scattering length, are exhibited. The theory is

Juan I. Climente, Andrea Bertoni, Massimo Rontani, Guido Goldoni

We study acoustic-phonon-induced relaxation of charge excitations in single and tunnel-coupled quantum dots containing few confined interacting electrons. The Full Configuration Interaction approach is used to account for the electron-electron repulsion. Electron-phonon interaction is accounted for through both deformation potential and piezoelectric field m

Martin W. Zwierlein, Christian H. Schunck, Andre Schirotzek, Wolfgang Ketterle

Water freezes into ice, atomic spins spontaneously align in a magnet, liquid helium becomes superfluid: Phase transitions are dramatic phenomena. However, despite the drastic change in the system&#39;s behaviour, observing the transition can sometimes be subtle. The hallmark of Bose-Einstein condensation (BEC) and superfluidity in trapped, weakly interacting

M. Tyunina, J. Levoska, I. Jaakola

Epitaxial thin films of relaxor PbMg1/3Nb2/3O3 and PbSc0.5Nb0.5O3, and ferroelectric PbZr0.65Ti0.35O3, Pb0.955La0.045Zr0.65Ti0.35O3, and Ba0.4Sr0.6TiO3 were prepared, and their dielectric properties were studied in a broad range of the measurement conditions. In the ferroelectric state, the presence and the change of configuration of the domains determined b

Chinmay Das, Daniel J. Read, Mark A. Kelmanson, Tom C. B. McLeish

We present a simple reaction kinetics model to describe the polymer synthesis used by Lusignan et al. (PRE, 60, 5657, 1999) to produce randomly branched polymers in the vulcanization class. Numerical solution of the rate equations gives probabilities for different connections in the final product, which we use to generate a numerical ensemble of representati

F. Aguilera-Granja, J. Ferrer, A. Vega

We present a thorough theoretical assessment of the stability of non-collinear spin arrangements in small palladium clusters. We generally find that ferromagnetic order is always preferred, but that antiferromagnetic and non-collinear configurations of different sorts exist and compete for the first excited isomers. We also show that the relative stability o

A. Dupuis, J. M. Yeomans

We use a free energy lattice Boltzmann approach to investigate numerically the dynamics of drops moving across superhydrophobic surfaces. The surfaces comprise a regular array of posts small compared to the drop size. For drops suspended on the posts the velocity increases as the number of posts decreases. We show that this is because the velocity is primari

Hsiung Chou, C. B. Wu, S. G. Hsu

La0.7Ce0.3MnO3 (LCeMO) is known usually called an electron doped colossal magnetotesistance material, which contains multiphase of n-type LCeMO, CeO2 and Mn-O. However, the present energy dispersion spectroscopy measurement shows that the La0.85Ce0.017MnO3+delta is the main phase in the bulk solid of material, which does not have the LCeMO phase. This findin

Toshiyuki Hamanaka, Akira Onuki

Using molecular dynamics simulation we examine changeovers among crystal, glass, and liquid at high density in a two dimensional binary mixture. We change the ratio between the diameters of the two components and the temperature. The transitions from crystal to glass or liquid occur with proliferation of defects. We visualize the defects in terms of a disord

Murilo L. Tiago, James R. Chelikowsky

Spectroscopic and optical properties of nanosystems and point defects are discussed within the framework of Green&#39;s function methods. We use an approach based on evaluating the self-energy in the so-called GW approximation and solving the Bethe-Salpeter equation in the space of single-particle transitions. Plasmon-pole models or numerical energy integrat

Akihiro Fujihara, Satoshi Tanimoto, Toshiya Ohtsuki, Hiroshi Yamamoto

Many-body stochastic processes with weighted multiplicative interactions are investigated analytically and numerically. An interaction rate between particles with quantities $x, y$ is controlled by a homogeneous symmetric kernel $K(x, y) \propto x^{w} y^{w}$ with a weight parameter $w$. When $w<0$, a method of moment inequalities is used to derive log-normal

Jörn Dunkel, Stefan Hilbert

We compare phase transition(-like) phenomena in small model systems for both microcanonical and canonical ensembles. The model systems correspond to a few classical (non-quantum) point particles confined in a one-dimensional box and interacting via Lennard-Jones-type pair potentials. By means of these simple examples it can be shown already that the microcan

A. M. Ettouhami, C. B. Doiron, F. D. Klironomos, R. Côté

We study the collective states formed by two-dimensional electrons in Landau levels of index $n\ge 2$ near half-filling. By numerically solving the self-consistent Hartree-Fock (HF) equations for a set of oblique two-dimensional lattices, we find that the stripe state is an anisotropic Wigner crystal (AWC), and determine its precise structure for varying val

C. H. Chen, B. A. Sargent, C. Bohac, K. H. Kim

We have obtained Spitzer Space Telescope IRS 5.5 - 35 micron spectra of 59 main sequence stars that possess IRAS 60 micron excess. The spectra of five objects possess spectral features that are well-modeled using micron-sized grains and silicates with crystalline mass fractions 0% - 80%, consistent with T-Tauri and Herbig AeBe stars. With the exception of et

Aaron J. Romanowsky

Planetary nebula are useful kinematic tracers of the stars in all galaxy types. I review recent observationally-driven developments in the study of galaxy mass profiles. These have yielded surprising results on spiral galaxy disk masses and elliptical galaxy halo masses. A key remaining question is the coupling between PNe and the underlying stellar populati

Slavko Bogdanov, Jonathan E. Grindlay, George B. Rybicki

X-ray emission from many rotation-powered millisecond pulsars (MSPs) is observed to be of predominantly thermal nature. In PSR J0437--4715, the nearest MSP known, an additional faint power-law tail is observed above 2.5 keV, commonly attributed to non-thermal magnetospheric radiation. We propose that the hard emission in this and other similar MSPs is instea

M. Goto, B. Stecklum, H. Linz, M. Feldt

We present high-resolution infrared imaging of the massive star-forming region around the O-star Herschel 36. Special emphasis is given to a compact infrared source at 0&#34;.25 southeast of the star. The infrared source, hereafter Her 36 SE, is extended in the broad-band images, but features spatially unresolved Br gamma line emission. The line-emission sou

Valentin D. Ivanov, D. Nuernberger, G. Chauvin, C. Foellmi

The multiplicity of early-type stars is still not well established. The studies of individual star forming regions suggest a connection with the age and the environment. To fill in this gap, we started the first detailed adaptive-optic-assisted imaging survey of 308 BA-type field stars within 300 pc from the Sun, to derive their multiplicity in a homogeneous

L. Raul Abramo, Laerte Sodre, Carlos Alexandre Wuensche

We discuss how an extended foreground of the cosmic microwave background (CMB) can account for the anomalies in the low multipoles of the CMB anisotropies. The distortion needed to account for the anomalies is consistent with a cold spot with the spatial geometry of the Local Supercluster (LSC) and a temperature quadrupole of order DeltaT_2^2 ~ 50 microK^2.

Knox S. Long, Gabriel Brammer, Cynthia S. Froning

Observations of U Gem with FUSE confirm that the WD is heated by the outburst and cools during quiescence. At the end of an outburst, the best uniform temperature WD model fits to the data indicate a temperature of 41,000 - 47,000 K, while in mid-quiescence, the temperature is 28,000 - 31,000 K, depending on the gravity assumed for the WD. Photospheric abund

R. B. C. Henry, A. Nava, Jason X. Prochaska

Chemical evolution models and Monte Carlo simulation techniques have been combined for the first time to study the distribution of blue compact galaxies on the N/O plateau. Each simulation comprises 70 individual chemical evolution models. For each model, input parameters relating to a galaxy&#39;s star formation history (bursting or continuous star formatio

Hector J. Martinez, Hernan Muriel

We analyse how the properties of galaxies in groups identified in the Sloan Digital Sky Survey depend on the environment. In particular, we study the relationship between galaxy properties and group mass and group-centric distance. Among the galaxy properties we have considered here, we find that the $g-r$ colour is the most predictive parameter for group ma