October 2006 arXiv papers — page 17

Fabien Amiot, Jean Paul Roger

We propose to use a Nomarski imaging interferometer to measure the out-of-plane displacement field of MEMS. It is shown that the measured optical phase arises both from height and slope gradients. Using four integrating buckets a more efficient approach to unwrap the measured phase is presented, thus making the method well suited for highly curved objects. S

V. I. Abrosimov, D. M. Brink, A. Dellafiore, F. Matera

A simplified version of the Wigner--transformed time--dependent Hartree--Fock--Bogoliubov equations, leading to a solvable model for finite systems of fermions with pairing correlations, is introduced. In this model, pairing correlations result in a coupling of the Vlasov--type equation for the normal phase--space density with that for the imaginary part of

W. Trautmann

Isotopic effects in spectator fragmentations following heavy-ion collisions at relativistic energies are investigated using data from recent exclusive experiments with SIS beams at GSI. Reactions of 12C on 112,124Sn at incident energies 300 and 600 MeV per nucleon were studied with the INDRA multidetector while the fragmentation of stable 124Sn and radioacti

Alex Arenas, Albert Diaz-Guilera, Conrad J. Perez-Vicente

We present an extended analysis, based on the dynamics towards synchronization of a system of coupled oscillators, of the hierarchy of communities in complex networks. In the synchronization process, different structures corresponding to well defined communities of nodes appear in a hierarchical way. The analysis also provides a useful connection between syn

O. A. Veliev

In this paper we obtain asymptotic formulas of arbitrary order for the Bloch eigenvalue and the Bloch function of the periodic Schrodinger operator of arbitrary dimension, when corresponding quasimomentum lies near a diffraction hyperplane. Besides, writing the asymptotic formulas for the Bloch eigenvalue and the Bloch function, when corresponding quasimomen

Michael Baake, Christian Huck

Various theoretical and algorithmic aspects of inverse problems in discrete tomography of planar Penrose model sets are discussed. These are motivated by the demand of materials science for the reconstruction of quasicrystalline structures from a small number of images produced by quantitative high resolution transmission electron microscopy.

Paolo Piccione, Daniel V. Tausk

We prove an existence result for local and global G-structure preserving affine immersions between affine manifolds. Several examples are discussed in the context of Riemannian and semi-Riemannian geometry, including the case of isometric immersions into Lie groups endowed with a left-invariant metric, and the case of isometric immersions into products of sp

Robert G. Donnelly

The numbers game is a one-player game played on a finite simple graph with certain ``amplitudes'' assigned to its edges and with an initial assignment of real numbers to its nodes. The moves of the game successively transform the numbers at the nodes using the amplitudes in a certain way. This game has been studied previously by Proctor, Mozes, Bjorn

Neil Epstein, Adela Vraciu

The $*$-spread of an ideal is defined as the minimal number of generators of an ideal which is minimal with respect to having the same tight closure as the original ideal. We prove an asymptotic length formula for the $*$-spread.

Xuan Hien Nguyen

We carry out the first main step towards the construction of new examples of complete embedded self-similar surfaces under mean curvature flow. An approximate solution is obtained by taking two known examples of self-similar surfaces and desingularizing the intersection circle using an appropriately modified singly periodic Scherk surface, called the core. U

Fabrizio Andreatta, Adrian Iovita

In this paper, given a smooth proper scheme X over a p-adic dvr and a p-power torsion etale local system L on it, we study a family of sheaves associated to the cohomology of local relative (Phi-Gamma)-modules of L and their cohomology. As applications we derive descriptions of the etale cohomology groups on the geometric generic fiber of X with values in L,

M. Neamtu, L. Buliga, F. R. Horhat, D. Opris

The aim of this paper is to study the steady states of the mathematical models with delay kernels which describe pathogen-immune dynamics of many kinds of infectious diseases. In the study of mathematical models of infectious diseases it is important to predict whether the infection disappears or the pathogens persist. The delay kernel is described by the me

Florentin Smarandache

Three generalizations of the well-known Ceva's Theorem are given in this paper and some applications.

Jean-Pierre Rosay

We show how to extend some holomorphic bundles with fifer C^2 and base an open set in C, to bundles on the Riemann Sphere, by an extremely simple technique. In particular, it applies to examples of non-Stein bundles constructed by Skoda and Demailly. It gives an example on C, with polynomial transition automorphisms.

Scott Zrebiec

We show that for Gaussian random SU(2)polynomials of a large degree $N$ the probability that there are no zeros in the disk of radius $r$ is less than $e^{-c_{1,r} N^2}$, and is also greater than $e^{-c_{2,r} N^2}$. Enroute to this result, we also derive a more general result: probability estimates for the event that the number of complex zeros of a random p

Sefi Ladkani

A finite poset X carries a natural structure of a topological space. Fix a field k, and denote by D(X) the bounded derived category of sheaves of finite dimensional k-vector spaces over X. Two posets X and Y are said to be derived equivalent if D(X) and D(Y) are equivalent as triangulated categories. We give explicit combinatorial properties of a poset which

Yi Ming Zou

The purpose of this short communication is to make some observations on the connections between various existing formulas of counting the number of sublattices of a fixed index in an $n$-dimensional lattice and their connection with the Gaussian binomials.

J. -P. Allouche, C. Frougny, K. G. Hare

We study Pisot numbers $β\in (1, 2)$ which are univoque, i.e., such that there exists only one representation of 1 as $1 = \sum_{n \geq 1} s_nβ^{-n}$, with $s_n \in \{0, 1\}$. We prove in particular that there exists a smallest univoque Pisot number, which has degree 14. Furthermore we give the smallest limit point of the set of univoque Pisot numbers.

T. Schreiber, Mathew D. Penrose, J. E. Yukich

Consider the random sequential packing model with infinite input and in any dimension. When the input consists of non-zero volume convex solids we show that the total number of solids accepted over cubes of volume $λ$ is asymptotically normal as $λ\to \infty$. We provide a rate of approximation to the normal and show that the finite dimensional distributions

Mathias Drton

Many statistical models are algebraic in that they are defined by polynomial constraints or by parameterizations that are polynomial or rational maps. This opens the door for tools from computational algebraic geometry. These tools can be employed to solve equation systems arising in maximum likelihood estimation and parameter identification, but they also p

Roman Kozhan

The notion of open-multicommutativity, introduced by Kozhan and Zarichnyi (2005), is investigated. The weakly normal covariant functor of upper-continuous capacities is considered. The main result of the paper is that this functor open-multicommutative.

Emmanuel Opshtein

In this paper we describe the intersection between the balls of maximal symplectic packings of $¶^2$. This analysis shows the existence of singular points for maximal packings of $¶^2$ by more than three equal balls. It also yields a construction of a class of very regular examples of maximal packings by five balls.

Hiroshi Tamaru

In this paper, we study the nilradicals of parabolic subalgebras of semisimple Lie algebras and the natural one-dimensional solvable extensions of them. We investigate the structures, curvatures and Einstein conditions of the associated nilmanifolds and solvmanifolds. We show that our solvmanifold is Einstein if the nilradical is of two-step. New examples of

Hiroshi Tamaru, Hisashi Yoshida

We classify connected Lie groups which are locally isomorphic to generalized Heisenberg groups. For a given generalized Heisenberg group $N$, there is a one-to-one correspondence between the set of isomorphism classes of connected Lie groups which are locally isomorphic to $N$ and a union of certain quotients of noncompact Riemannian symmetric spaces.

Kazuo Kaneko, Shoji Okumura

We will study two types of special solutions of the sixth Painleve equation, which are invariant under the symmetries obtained from the Backlund transformations. In most cases, the fixed points of the Backlund transformations are classical solution, but our solutions are not classical for generic parameters. We will calculate the linear monodromy of these so

Hiroki Shimakura

In this article, we study isomorphisms between simple current extensions of a simple VOA. For example, we classify the isomorphism classes of simple current extensions of some VOAs. Moreover, we consider the same simple current extension and describe the normalizer of the abelian automorphism group associated with this extension. In particular, we regard the

Qingxue Wang

In this paper, we give a natural construction of mixed Tate motives whose periods are a class of iterated integrals which include the multiple polylogarithm functions. Given such an iterated integral, we construct two divisors $A$ and $B$ in the moduli spaces $\mathcal{\bar{M}}_{0,n}$ of $n$-pointed stable curves of genus 0, and prove that the cohomology of

J. Kuttler, Z. Reichstein

Let G -> \GL(V) be a finite-dimensional linear representation of a reductive linear algebraic group G on a finite-dimensional vector space V, defined over an algebraically closed field of characteristic zero. The categorical quotient V//G carries a natural stratification, due to D. Luna. This paper addresses the following questions: (i) Is the Luna stratific

Ruth Charney

Recently, right-angled Artin groups have attracted much attention in geometric group theory. They have a rich structure of subgroups and nice algorithmic properties, and they give rise to cubical complexes with a variety of applications. This survey article is meant to introduce readers to these groups and to give an overview of the relevant literature.

G. Mircea, M. Neamtu, R. F. Horhat, D. Opris

We consider the model of interaction between the immune system and tumor cells including a memory function that reflect the influence of the past states, to simulate the time needed by the latter to develop a chemical and cell mediated response to the presence of the tumor. The memory function is called delay kernel. The results are compared with those from

Roland K. W. Roeder

We demonstrate how to construct three-dimensional compact hyperbolic polyhedra using Newton's Method. Under the restriction that the dihedral angles are non-obtuse, Andreev's Theorem provides as necessary and sufficient conditions five classes of linear inequalities for the dihedral angles of a compact hyperbolic polyhedron realizing a given combinat

Ryo Takahashi, Kei-ichi Watanabe

In this paper, from an arbitrary smooth projective curve of genus at least two, we construct a non-Gorenstein Cohen-Macaulay normal domain and a nonfree totally reflexive module over it.

Erwan Rousseau

The main goal of this work is to prove that every entire curve in a smooth hypersurface of degree greater than or equal to 97 in the complex projective space of dimension 4 must satisfy an algebraic differential equation of order 3. A logarithmic version of this result is given proving that every entire curve in the complement of a smooth surface of degree g

F. Klebaner, R. Liptser

We consider a continuous time version of Cramer's theorem with nonnegative summands $ S_t=\frac{1}{t}\sum_{i:τ_i\le t}ξ_i, t \to\infty, $ where $(τ_i,ξ_i)_{i\ge 1}$ is a sequence of random variables such that $tS_t$ is a random process with independent increments.

Erwan Rousseau

Demailly-Semple jets are studied using the invariant theory of non reductive groups. The geometric characterization of the 3-jets bundle in dimension 3 is given and provides a Riemann-Roch computation.

Yaroslav Kurylev, Matti Lassas

We consider a Dirac-type operator $D_P$ on a vector bundle $V$ over a compact Riemannian manifold $(M,g)$ with a nonempty boundary. The operator $D_P$ is specified by a boundary condition $P(u|_{\p M})=0$ where $P$ is a projector which may be a non-local, i.e. a pseudodifferential operator. We assume the existence of a chirality operator which decomposes $L^

Roberto Casalbuoni

I review the paper of Majorana about relativistic particles with arbitrary spin written in 1932. The main motivation for this papers was the dissatisfaction about the negative energy solutions of the Dirac equation. As such, the paper became immediately obsolete due to the almost contemporaneous discovery of the positron. However, for the first time, the uni

M. Aganagic, C. Beem, J. Seo, C. Vafa

We construct metastable configurations of branes and anti-branes wrapping 2-spheres inside local Calabi-Yau manifolds and study their large N duals. These duals are Calabi-Yau manifolds in which the wrapped 2-spheres have been replaced by 3-spheres with flux through them, and supersymmetry is spontaneously broken. The geometry of the non-supersymmetric vacuu

H. F. Jones, J. Mateo, R. J. Rivers

It can be shown using operator techniques that the non-Hermitian $PT$-symmetric quantum mechanical Hamiltonian with a "wrong-sign" quartic potential $-gx^4$ is equivalent to a Hermitian Hamiltonian with a positive quartic potential together with a linear term. A naive derivation of the same result in the path-integral approach misses this linear term

Vladimir S. Dotsenko, Benoit Estienne

Using the renormalization group approach, the Coulomb gas and the coset techniques, the effect of slightly relevant perturbations is studied for the second parafermionic field theory with the symmetry $Z\_{5}$. New fixed points are found and classified.

M. H. Dehghani, H. R. Rastegar Sedehi

We construct a new class of charged rotating solutions of $(n+1)$-dimensional Einstein-Born-Infeld gravity with cylindrical or toroidal horizons in the presence of cosmological constant and investigate their properties. These solutions are asymptotically (anti)-de Sitter and reduce to the solutions of Einstein-Maxwell gravity as the Born-Infeld parameters go

Michel de Haan

The reformulation of field theory in which self-energy processes are no longer present [Annals of Physics, {\bf311} (2004), 314.], [ Progr. Theor. Phys., {\bf 109} (2003), 881.], [Trends in Statistical Physics {\bf 3} (2000), 115.] provides an adequate tool to transform Swinger-Dyson equations into a kinetic description outside any approximation scheme. Usua

Zhenyu Han

We discuss electroweak constraints on TeV scale extensions of the standard model. To obtain model-independent results, effective theory approach is adopted. Constraints are given on arbitrary linear combinations of a set of dimension-6 operators that respect the SM gauge symmetry, as well as CP, lepton and baryon number conservation. Applications of the resu

Cyrille Marquet

I discuss the saturation regime of QCD: the weak-coupling regime that describes large parton densities inside hadrons and the resulting high-energy behavior of scattering amplitudes. I briefly review past successes in the context of deep inelastic scattering at HERA and forward particle production at RHIC, and I present some recent progresses that significan

Urs M. Heller

The MILC collaboration has been performing realistic simulations of full QCD with 2+1 flavors of improved staggered quarks. Our simulations allow for controlled continuum and chiral extrapolations. I present results for the light pseudoscalar sector: masses and decay constants, quark masses and Gasser-Leutwyler low-energy constants. In addition I will presen

Dang Van Soa, Dao Le Thuy

The $\mathrm {SU}(3)_C\otimes \mathrm {SU}(3)_L \otimes {\mathrm U}(1)_X$ gauge model with two Higgs triplets (the economical 3-3-1 model) are presented. This model predicts a new singly-charged Higgs bosons $H_2^\pm$, namely a scalar bilepton (a particle of lepton number 2) with mass proportional to the bilepton mass $M_Y$ through the coefficient $\la_4$. P

M. M. Block, E. L. Berger, C. -I. Tan

We fit the reduced cross section for deep-inelastic electron scattering data to a three parameter ln^2 s fit, A + beta ln^2 (s/s_0), where s= [Q^2/x] (1-x) + m^2, and Q^2 is the virtuality of the exchanged photon. Over a wide range in Q^2 (0.11 < Q^2 < 1200 GeV^2) all of the fits satisfy the logarithmic energy dependence of the Froissart bound. We can use th

Rachel Jeannerot

In this talk, I shall focus on theories beyond the Standard Model which predict massive neutrinos. Hybrid inflation emerges naturally in these theories: the slow-rolling inflaton field is a gauge singlet which couples with a GUT Higgs field which triggers the end of inflation. In the standard scenario, spontaneous symmetry breaking takes place at the end of

T. Heinzl

We suggest a possible algorithm to calculate one-loop n-point functions within a variant of light-front perturbation theory. The key ingredients are the covariant Passarino-Veltman scheme and a surprising integration formula that localises Feynman integrals at vanishing longitudinal momentum. The resulting expressions are generalisations of Weinberg&#39;s in

Marc Wagner

The pseudoparticle approach is a numerical method to approximate path integrals in SU(2) Yang-Mills theory. Path integrals are computed by summing over all gauge field configurations, which can be represented by a linear superposition of a small number of pseudoparticles with amplitudes and color orientations as degrees of freedom. By comparing different pse

P. Gonzalez, J. Vijande, A. Valcarce, H. Garcilazo

We revise the role played by symmetry in the study of the low-lying baryon spectrum and comment on the difficulties when trying to generalize the symmetry pattern to higher energy states. We show that for the $(N,Δ)$ part such a generalization is plausible allowing the identification of spectral regularities and the prediction of until now non-identified res

J. Vijande, N. Barnea, A. Valcarce

We present an exact method based on a hyperspherical harmonic expansion to study systems made of quarks and antiquarks of the same flavor. Our formalism reproduces and improves the results obtained with variational approaches. This analysis shows that identical-flavor four-quark systems with non-exotic $2^{++}$ quantum numbers may be bound independently of t

G. Nardulli

At high nuclear density and small temperature, due to the asymptotic freedom property of Quantum ChromoDynamics and to the existence of an attractive channel in the color interaction, diquark condensates might be formed. Since these condensates break the color gauge symmetry, this phenomenon has the name of color superconductivity. In the last few years this

Sally Dawson, Chung Kao, Yili Wang, Peter Williams

We present a complete next-to-leading order (NLO) calculation for the total cross section of inclusive Higgs pair production via bottom-quark fusion ($b\bar{b} \to hh$) at the CERN Large Hadron Collider (LHC) in the Standard Model. The NLO QCD corrections lead to less dependence on the renormalization scale ($μ_R$) and the factorization scale ($μ_F$) than th

A. Schoning

I discuss a proposal for a high intensity $e^+e^-$ linear collider operated at low center of mass energies $\sqrt{s}<5$ GeV with high intensity beams. Such a facility would provide high statistics samples of (charmed) vector mesons and would permit searches for LFV with unprecedented precision in decays of $τ$ leptons and mesons. Implications on the design o

Belle Collaboration

We report an improved measurement of the decay $B^0 \to π^0 π^0$, using a data sample of 535 $\times 10^6 B\bar{B}$ pairs collected at the $Υ(4S)$ resonance with the Belle detector at the KEKB asymmetric energy $e^+ e^-$ collider. The measured branching fraction is ${\cal B}(B^0 \to π^0 π^0) = 1.1\pm 0.3(stat.) \pm 0.1(syst.)$, with a significance of 5.4 sta

D. Burlankov

The exact solution for dynamic of conform-flat space homogeneous since dynamic equation is given. Conform mode of space metric changing in Global time theory has negative energy density. Swap of energy to this mode from another ones lead to increasing of Universe homogeneity although probability of this swap from local objects is negligibly small. Conform mo

Richard G. Clegg, Maurice Dodson

This paper describes a model for generating time series which exhibit the statistical phenomenon known as long-range dependence (LRD). A Markov Modulated Process based upon an infinite Markov chain is described. The work described is motivated by applications in telecommunications where LRD is a known property of time-series measured on the internet. The pro

Kwankyu Lee, Michael E. O&#39;Sullivan

List decoding of Hermitian codes is reformulated to allow an efficient and simple algorithm for the interpolation step. The algorithm is developed using the theory of Groebner bases of modules. The computational complexity of the algorithm seems comparable to previously known algorithms achieving the same task, and the algorithm is better suited for hardware

Loris Marchal, Veronika Rehn, Yves Robert, Frédéric Vivien

In this work we are interested in the problem of scheduling and redistributing data on master-slave platforms. We consider the case were the workers possess initial loads, some of which having to be redistributed in order to balance their completion times. We examine two different scenarios. The first model assumes that the data consists of independent and i

Evgueni A. Haroutunian

Random coding, expurgated and sphere packing bounds are derived by method of types and method of graph decomposition for $E$-capacity of discrete memoryless channel (DMC). Three decoding rules are considered, the random coding bound is attainable by each of the three rules, but the expurgated bound is achievable only by maximum-likelihood decoding. Sphere pa

Ismail Gunes, Haluk Bingol

Community structure identification has been one of the most popular research areas in recent years due to its applicability to the wide scale of disciplines. To detect communities in varied topics, there have been many algorithms proposed so far. However, most of them still have some drawbacks to be addressed. In this paper, we present an agent-based based c

J. Kienert, S. Schwieger, K. Lenz, J. Lindner

Temperature dependent FMR-measurements of Ni and Co films are analysed using a microscopic theory for ultrathin metallic systems. The mechanism governing the temperature dependence of the magnetic anisotropy energy is identified and discussed. It is reduced with increasing temperature. This behavior is found to be solely caused by magnon excitations.

Vivek aji, C. M. Varma

The statistical mechanics of the time-reversal and inversion symmetry breaking order parameter, possibly observed in the pseudogap region of the phase diagram of the Cuprates, can be represented by the Ashkin-Teller model. We add kinetic energy and dissipation to the model for a quantum generalization and show that the correlations are determined by two sets

Manuel Torres, Alejandro Kunold

We study the microwave-induced photoconductivity of a two-dimensional electron system (2DES) in the presence of a magnetic field and a two-dimensional modulation. The microwave and Landau contributions are exactly taken into account, while the periodic potential is treated perturbatively. The longitudinal resistivity exhibits oscillations, periodic in $ω/ ω_

Surachate Limkumnerd James P. Sethna

Using a recently developed continuum theory of dislocation dynamics, we derive three new predictions about plasticity and grain boundary formation in crystals. (1) There will be a residual stress jump across grain boundaries and plasticity-induced cell walls, which self-consistently acts to form the boundary by attracting neighboring dislocations; we derive

V. Turkowski, J. K. Freericks

We perform a perturbative analysis for the nonequilibrium Green functions of the spinless Falicov-Kimball model in the presence of an arbitrary external time-dependent but spatially uniform electric field. The conduction electron self-energy is found from a strictly truncated second-order perturbative expansion in the local electron-electron repulsion U. We

G. Nandi, R. Walser, E. Kajari, W. P. Schleich

We describe the non-relativistic time evolution of an ultra-cold degenerate quantum gas (bosons/fermions) falling in Earth&#39;s gravity during long times (10 sec) and over large distances (100 m). This models a drop tower experiment that is currently performed by the QUANTUS collaboration at ZARM (Bremen, Germany). Starting from the classical mechanics of t

I. Neder

A theoretical non-pertubative treatment is developed to explain the dephasing of electrons in the electronic Mach-Zehnder interferometer via interaction with a near-by partitioned electronic channel, which acts as a &#34;which path&#34; detector. The resulting formula reproduces the recant experimental behavior of the MZI interference visibility. By fitting

I. Neder, F. Marquardt, M. Heiblum, D. Mahalu

In a &#39;controlled dephasing&#39; experiment [1-3], an interferometer loses its coherence due to entanglement with a controlled quantum system (&#39;which path&#39; detector). In experiments that were conducted thus far in mesoscopic systems only partial dephasing was achieved. This was due to weak interactions between many detector electrons and the inter

J. Ruiz, E. Jódar, V. Gasparian

We study the distributions functions for global partial density of states (GPDOS) in quasi-one-dimensional (Q1D) disordered wires as a function of disorder parameter from metal to insulator. We consider two different models for disordered Q1D wire: a set of two dimensional $δ$ potentials with an arbitrary signs and strengths placed randomly, and a tight-bind

N. Pompeo, E. Silva, R. Marcon, V. Galluzzi

We present measurements of the microwave complex surface impedance at 47.7 GHz in YBa$_2$Cu$_3$O$_{7-δ}$ (YBCO) films deposited by pulsed laser deposition with the explicit goal to introduce BaZrO$_3$ (BZO) nanoinclusions. Composite targets obtained by addition of BZO powder in molar percents ranging from 2.5 to 7 mol.% have been prepared and characterized.

Philippe Colomban

The micro/nano-structural evolution before and after tensile/compressive loading, fatigue and ultimately, failure has been studied by Raman (and IR) microspectroscopy for PBO, PET, PA66, PP, silk and hair using three probes: low wavenumber collective modes at <150cm-1 as representative of the crystalline/ordered and amorphous chains, stretching and bending m

Xiao-Yong Feng, Guang-Ming Zhang, Tao Xiang

We have introduced a novel Majorana representation of S=1/2 spins using the Jordan-Wigner transformation and have shown that a generalized spin model of Kitaev defined on a brick-wall lattice is equivalent to a model of non-interacting Majorana fermions with Z_2 gauge fields without redundant degrees of freedom. The quantum phase transitions of the system at

Yiping Chen, Gerald Paul, Reuven Cohen, Shlomo Havlin

We apply percolation theory to a recently proposed measure of fragmentation $F$ for social networks. The measure $F$ is defined as the ratio between the number of pairs of nodes that are not connected in the fragmented network after removing a fraction $q$ of nodes and the total number of pairs in the original fully connected network. We compare $F$ with the

M. A. Continentino, A. S. Ferreira

Quantum phase transitions have been the subject of intense investigations in the last two decades [1]. Among other problems, these phase transitions are relevant in the study of heavy fermion systems, high temperature superconductors and Bose-Einstein condensates. More recently there is increasing evidence that in many systems which are close to a quantum cr

J. -P. Cleuziou, W. Wernsdorfer, V. Bouchiat, Th. Ondarcuhu

We recently presented the first superconducting quantum interference device (SQUID) with single-walled carbon nanotube (CNT) Josephson junctions [1: J. P. Cleuziou, W. Wernsdorfer, V. Bouchiat, T. Ondarcuhu and M. Monthioux, Nature Nanotech. 1, 53, (2006).], http://www.nature.com/nnano/journal/v1/n1/pdf/nnano.2006.54.pdf . We showed that quantum confinement

Alexei Grechnev, Igor Di Marco, M. I. Katsnelson, A. I. Lichtenstein

The correlated electronic structure of iron, cobalt and nickel is investigated within the dynamical mean-field theory formalism, using the newly developed full-potential LMTO-based LDA+DMFT code. Detailed analysis of the calculated electron self-energy, density of states and the spectral density are presented for these metals. It has been found that all thes

D. Senff, P. Link, K. Hradil, A. Hiess

The magnetic excitations in multiferroic TbMnO3 have been studied by inelastic neutron scattering in the spiral and sinusoidally ordered phases. At the incommensurate magnetic zone center of the spiral phase, we find three low-lying magnons whose character has been fully determined using neutron-polarization analysis. The excitation at the lowest energy is t

Alejandro B. Kolton

We study numerically the overdamped motion of particles driven in a two dimensional ratchet potential. In the proposed design, of the so-called geometrical-ratchet type, the mean velocity of a single particle in response to a constant force has a transverse component that can be induced by the presence of thermal or other unbiased fluctuations. We find that

Christian Ertler, Jaroslav Fabian

A device which converts analog magnetic signals directly into digital information is proposed. The device concept is based on the monostable-bistable transition logic element, which consists of two resonant tunneling diodes (load and driver) connected in series and employs the monostable to bistable working point transition of the circuit. Using a magnetic r

D. Felbacq, G. Bouchitté, A. Moreau

We study wave propagation and diffraction in a bidimensional photonic crystal with finite height, in case where the wavelength is large with respect to the period of the structure. The device is made of materials with anisotropic permittivity and permeability tensors. We derive rigorously the homogenized system, using the concept of two-scale convergence. Th

Yvan Sidis, Benoit Fauqué, Vivek Aji, Philippe Bourges

We review experimental attempts using polarized neutron scattering technique to reveal the existence in high temperature superconductors of a long-range ordered state characterized by the spontaneous appearance of current loops. We draw a particular attention to our recent results (B. Fauqué {\it et al.}, {\it Phys. Rev. Lett.} {\bf 96}, 197001 (2006)) that,

B. Delamotte, Yu. Holovatch, D. Ivaneyko, D. Mouhanna

The Comment of A. Pelissetto and E. Vicari (cond-mat/0610113) on our article (cond-mat/0609285) is based on misunderstandings of this article as well as on unfounded implicit assumptions. We clarify here the controversial points and show that, contrary to what is asserted by these authors, our paper is free of any contradiction and agrees with all well-estab

Shuai Dong, J. -M. Liu

A new type of charge-ordering pattern for Pr1-xCaxMnO3: a hybridization of site- and bond-centred ordering (SBCO) was proposed by Efremov et al.. It was believed this discovery opened a new route to magnetic ferroelectrics. Here we argue that the possible ferroelectric of Pr1-xCaxMnO3 also originates from the cation displacement, similar to prototypical ferr

R. J. Radwanski, Z. Ropka

We have described properties of LiCoO_2 within the Quantum Atomistic Solid State (QUASST) theory taking into account very strong electron correlations, predominantly of the intra-atomic origin, spin-orbit coupling and the detailed local crystallographic surroundings and its symmetry. Properties of LiCoO_2 are consistently explained together with NaCoO_2 and

David J. Masiello, William P. Reinhardt

The many-body structure of high-lying excited states, including macroscopic quantum superpositions, of the gaseous double-well BEC is presented within the context of a multiconfigurational bosonic self-consistent field theory based upon underlying symmetry-broken one-body wave functions. To better understand our initial results, a model is constructed in the

T. Yokoyama, Y. Tanaka, A. A. Golubov

Using the quasiclassical Green&#39;s function formalism, we study the influence of the odd-frequency spin-triplet superconductivity on the local density of states (LDOS) in a diffusive ferromagnet (DF) attached to a superconductor. Various possible symmetry classes in a superconductor are considered which are consistent with the Pauli&#39;s principle: even-f

T. Yokoyama, Y. Sawa, Y. Tanaka, A. A. Golubov

Josephson effect in junctions between unconventional superconductors is studied theoretically within the model describing the effects of interface roughness. The particularly important issue of applicability of the frequently used Sigrist-Rice formula for Josephson current in d-wave superconductor / insulator / d-wave superconductor junctions is addressed. W

Lina Guo, Jiulin Du

The kappa-deformed statistics has been studied in many papers. It is naturally important question for us to ask what should the kappa parameter stand for and under what physical situation should the kappa-deformed statistics be suitable for the statistical description of a system. In this paper, we have derived a formula expression of kappa parameter based o

Mario Einax, Stefan Heinrichs, Philipp Maass, Andrzej Majhofer

Kinetic Monte Carlo simulations are performed to study the influence of external magnetic fields on the growth of magnetic fcc binary alloy nanoclusters with perpendicular magnetic anisotropy. The underlying kinetic model is designed to describe essential structural and magnetic properties of CoPt_3-type clusters grown on a weakly interacting substrate throu

M. Grochol, F. Grosse, R. Zimmermann

The optical exciton Aharonov-Bohm effect, i. e. an oscillatory component in the energy of optically active (bright) states, is investigated in nanorings. It is shown that a small effective electron mass, strong confinement of the electron, and high barrier for the hole, achieved e. g. by an InAs nanoring embedded in an AlGaSb quantum well, are favorable for

Fabio Bresolin

I present deep spectroscopy of four HII regions in the inner, metal-rich zone of the spiral galaxy M101 obtained with the LRIS spectrograph at the Keck telescope. From the analysis of the collisionally excited lines in two of the target HII regions, H1013 and H493, I have obtained oxygen abundances 12+log(O/H)=8.52 and 12+log(O/H)=8.74, respectively. These m

Bruce G. Elmegreen

The stellar initial mass function (IMF) in star clusters is reviewed. Uncertainties in the observations are emphasized. We suggest there is a distinct possibility that cluster IMFs vary systematically with density or pressure. Dense clusters could have additional formation processes for massive stars that are not present in low density regions, making the sl

Frank C. van den Bosch, Xiaohu Yang, H. J. Mo, Simone M. Weinmann

We use the conditional luminosity function (CLF) and data from the 2dFGRS to constrain the average relation between light and mass in a LCDM cosmology with Omega_m=0.23 and sigma_8=0.74 (hereafter WMAP3 cosmology). Reproducing the observed luminosity dependence of the galaxy two-point correlation function results in average mass-to-light ratios that are abou

Louis J. Rubbo

By being the first observatory to survey the source rich low frequency region of the gravitational wave spectrum, the Laser Interferometer Space Antenna (LISA) will revolutionize our understanding of the Cosmos. For the first time we will be able to detect the gravitational radiation from millions of galactic binaries, the coalescence of two massive black ho

M. S. Pshirkov, M. V. Sazhin

An influence of the weak microlensing effect on the pulsar timing is investigated for pulsar B1937+21. Average residuals of Time of Arrival (TOA) due to the effect would be as large as 10 ns in 20 years observation span. These residuals can be much greater (up to 1 ms in 20 years span) if pulsar is located in globular cluster (or behind it).

Guenter Sigl, Jeremy Schnittman, Alessandra Buonanno

We consider a model in which massive stars form in a self-gravitating accretion disk around an active galactic nucleus (AGN). These stars may evolve and collapse to form compact objects on a time scale shorter than the accretion time, thus producing an important family of sources for LISA. Assuming the compact object formation/inspiral rate is proportional t

Bruce G. Elmegreen

Clusters are the dense inner regions of a wide-spread hierarchy of young stellar structures. They often reveal a continuation of this hierarchy inside of them, to smaller scales, when they are young, but orbital mixing eventually erases these subparts and a only smooth cluster or smooth unbound group remains. The stellar hierarchy follows a similar structure

Dharam Vir Lal, A. Pramesh Rao

We present results from a study of X-shaped sources based on observations using the Giant Metrewave Radio Telescope (GMRT). These observations were motivated by our low frequency study of 3C 223.1 (Lal & Rao 2005), an X-shaped radio source, which showed that the wings (or low-surface-brightness jets) have flatter spectral indices than the active lobes (or hi