July 2006 arXiv papers — page 5

O. Arcizet, P. -F. Cohadon, T. Briant, M. Pinard

Recent experimental progress in table-top experiments or gravitational-wave interferometers has enlightened the unique displacement sensitivity offered by optical interferometry. As the mirrors move in response to radiation pressure, higher power operation, though crucial for further sensitivity enhancement, will however increase quantum effects of radiation

Julia Kempe, Laszlo Pyber, Aner Shalev

We study permutation groups of given minimal degree without the classical primitivity assumption. We provide sharp upper bounds on the order of a permutation group of minimal degree m and on the number of its elements of any given support. These results contribute to the foundations of a non-commutative coding theory. A main application of our results concer

S. Garnerone, A. Marzuoli, M. Rasetti

Motivated by algorithmic problems arising in quantum field theories whose dynamical variables are geometric in nature, we provide a quantum algorithm that efficiently approximates the colored Jones polynomial. The construction is based on the complete solution of Chern-Simons topological quantum field theory and its connection to Wess-Zumino-Witten conformal

Bayram Kurucay

Recent experiments with trapped alkali atoms have drawn enormous interest to the theoretical studies concerning Bose-Einstein condensation. The purpose of this paper is to review one of the approaches to study bosonic matter at zero temperature, namely the Bogoliubov approximation. Review of a necessary tool, the second quantization, will also be made.

Sergio De Nicola, Renato Fedele, Margarita A. Man'ko, Vladimir I. Man'ko

Using the tomographic probability distribution (symplectic tomogram) describing the quantum state (instead of the wave function or density matrix) and properties of recently introduced tomographic entropy associated with the probability distribution, the new uncertainty relation for the tomographic entropy is obtained. Examples of the entropic uncertainty re

Solomon Duki, H. Mathur, Onuttom Narayan

Marzlin and Sanders \cite{marzlin} have shown rigorously that the adiabatic approximation can be very inaccurate when applied to a Hamiltonian $H(t)$ that generates the evolution $U^{\dagger} (t)$ even if it gives an excellent approximation to the evolution $U(t)$ generated by a dual Hamiltonian $h(t)$. We show that this is not inconsistent with the adiabati

P. D. Mininni, A. Pouquet, D. C. Montgomery

We investigate using direct numerical simulations with grids up to 1536^3 points, the rate at which small scales develop in a decaying three-dimensional MHD flow both for deterministic and random initial conditions. Parallel current and vorticity sheets form at the same spatial locations, and further destabilize and fold or roll-up after an initial exponenti

Jinyu Li, Philip C. Nelson, M. D. Betterton

Many proteins interact with and deform double-stranded DNA in cells. Single-molecule experiments have studied the elasticity of DNA with helix-deforming proteins, including proteins that bend DNA. These experiments increase the need for theories of DNA elasticity which include helix-deforming proteins. Previous theoretical work on bent DNA has examined a lon

Josep Perello

The expOU stochastic volatility model is capable of reproducing fairly well most important statistical properties of financial markets daily data. Among them, the presence of multiple time scales in the volatility autocorrelation is perhaps the most relevant which makes appear fat tails in the return distributions. This paper wants to go further on with the

Caglar Tuncay

A model on the effects of leader, media, viruses, and worms and other agents on the opinion of individuals is developed and utilized to simulate the formation of consensus in society and price in market via excess between supply and demand. Effects of some time varying drives, (harmonic and hyperbolic) are also investigated. Key words: Opinion; Leader; Media

D. Rannacher, A. Engel

The Rayleigh-Taylor instability of a magnetic fluid superimposed on a non-magnetic liquid of lower density may be suppressed with the help of a spatially homogeneous magnetic field rotating in the plane of the undisturbed interface. Starting from the complete set of Navier-Stokes equations for both liquids a Floquet analysis is performed which consistently t

Erhard Wielandt

In 1992 M.W. Evans proposed a so-called O(3) symmetry of electromagnetic fields by adding a constant longitudinal "ghost field" to the well-known transversal plane em waves. He considered this symmetry as a new law of electromagnetics. Later on, since 2002, this O(3) symmetry became the center of his Generally Covariant Unified Field Theory which he

M. A. Thomson

One of the most important requirements for a detector at the ILC is good jet energy resolution. It is widely believed that the particle flow approach to calorimetry is the key to achieving the goal of 0.3/sqrt(E[GeV]). This paper describes the current performance of the PandoraPFA particle flow algorithm. For 45 GeV jets in the Tesla TDR detector concept, th

Michael Scalora, Domenico de Ceglia, Giuseppe D'Aguanno, Nadia Mattiucci

By integrating the full Maxwell's equations we predict the existence of gap solitons in a quadratic, Fabry-Perot negative index cavity. An intense, fundamental pump pulse shifts the band structure that forms when magnetic and electric plasma frequencies are different so that a weak, second harmonic pulse initially tuned inside the gap is almost entirely

Arnab Chatterjee, Bikas K Chakrabarti

We analyze the ideal gas like models of markets and review the different cases where a `savings' factor changes the nature and shape of the distribution of wealth. These models can produce similar distribution of wealth as observed across varied economies. We present a more realistic model where the saving factor can vary over time (annealed savings) and

Yosef Pinhasi, Yuri Lurie, Asher Yahalom

A three-dimensional, space-frequency model for simulation of interaction in free-electron lasers (FELs) is presented. The model utilizes an expansion of the total electromagnetic field (radiation and space-charge waves) in terms of transverse eigenmodes of the waveguide, in which the field is excited and propagates. The mutual interaction between the electro

Laszlo B. Kish

This is the longer (partially unpublished) version of response; the shorter version (http://arxiv.org/abs/physics/0605013) is published in Physics Letters A. We point out that the claims in the comment-paper of Scheuer and Yariv are either irrelevant or incorrect. We first clarify what the security of a physically secure layer means. The idealized Kirchoff-l

Jozsef Garai

Experiments show that all the derivatives of the thermo-physical variables are nearly constant. The constant value of the derivatives indicates linear relationship between the variables. Neither the volume coefficient of thermal expansion nor the bulk modulus are constant and show pressure and temperature dependence. Besides the derivatives the only other qu

Jozsef Garai

Theoretically predicted linear correlation between the volume coefficient of thermal expansion and the thermal heat capacity was investigated for highly symmetrical atomic arrangements. Normalizing the data of these thermodynamic parameters to the Debye temperature gives practically identical curves from zero Kelvin to the Debye temperature. This result is c

N. Borghini, J. -Y. Ollitrault

If the matter produced in ultrarelativistic heavy-ion collisions reaches thermal equilibrium, its subsequent evolution follows the laws of ideal fluid dynamics. We show that general predictions can be made on this basis alone, irrespective of the details of the hydrodynamical model. We derive several scaling rules for momentum spectra and anisotropic flow (i

Taro Hamamoto, Kenji Kajiwara, Nicholas S. Witte

A class of classical solutions to the $q$-Painlevé equation of type $(A_1+A_1')^{(1)}$ (a $q$-difference analog of the Painlevé II equation) is constructed in a determinantal form with basic hypergeometric function elements. The continuous limit of this $q$-Painlevé equation to the Painlevé II equation and its hypergeometric solutions are discussed. The

Estelle L. Basor, Torsten Ehrhardt

We compute the asymptotics of a block Toeplitz determinant which arises in the classical dimer model for the triangular lattice when considering the monomer-monomer correlation function. The model depends on a parameter interpolating between the square lattice ($t=0$) and the triangular lattice ($t=1$), and we obtain the asymptotics for $0<t\le 1$. For $0<t<

Daniel Braun

I adapt a recently introduced method for integrating over the unitary group (S. Aubert and C.S. Lam, J.Math.Phys. 44, 6112-6131 (2003)) to the orthogonal group. I derive explicit formulas for a number of one, two and three-vector integrals, as well as recursion formulas for more complicated cases.

Chongying Dong, Cuipo Jiang

This paper studies the twisted representations of vertex operator algebras. Let V be a vertex operator algebra and g an automorphism of V of finite order T. For any m,n in (1/T)Z_+, an A_{g,n}(V)-A_{g,m}(V)-bimodule A_{g,n,m}(V) is constructed. The collection of these bimodules determines any admissible g-twisted V-module completely. A Verma type admissible

Artur Avila, Marcelo Viana

We exhibit an explicit sufficient condition for the Lyapunov exponents of a linear cocycle over a Markov map to have multiplicity 1. This builds on work of Guivarc&#39;h-Raugi and Gol&#39;dsheid-Margulis, who considered products of random matrices, and of Bonatti-Viana, who dealt with the case when the base dynamics is a subshift of finite type. Here the Mar

Igor Pak

We give a simple proof of the following result: There exists a non-convex polyhedron whose surface is isometric to the surface of a cube of smaller volume.

Erwin Lutwak, Deane Yang, Gaoyong Zhang

A direct approach to Ball&#39;s simplex inequality is presented. This approach, which does not use the Brascamp-Lieb inequality, also gives Barthe&#39;s characterization of the simplex for Ball&#39;s inequality and extends it from discrete to arbitrary measures. It also yields the dual inequality, along with equality conditions, and it does both for arbitrar

Dmitry N. Kozlov

We describe a simple homological test for obstructions to graph colorings. The main idea is to combine the framework of Hom-complexes with the following general fact: an arbitrary Z_2-space has nontrivial homology with Z_2-coefficients in the dimension equal to its Stiefel-Whitney height. Actually, as a result we have a whole family of homology tests, one fo

Rafael López

In this paper we study surfaces in Euclidean 3-space foliated by pieces of circles and that satisfy a Weingarten condition of type $a H+b K=c$, where $a,b$ and $c$ are constant and $H$ and $K$ denote the mean curvature and the Gauss curvature respectively. We prove that a such surface must be a surface of revolution, a Riemann minimal surface or a generalize

Rafael López

In this paper we study surfaces in Euclidean 3-space that satisfy a Weingarten condition of linear type as $κ_1=m κ_2 +n$, where $m$ and $n$ are real numbers and $κ_1$ and $κ_2$ denote the principal curvatures at each point of the surface. We investigate the possible existence of such surfaces parametrized by a uniparametric family of circles. Besides the su

Claire David, Pierre Sagaut

The aim of this work is to develop general optimization methods for finite difference schemes used to approximate linear differential equations. The specific case of the transport equation is exposed. In particular, the minimization of the numerical error is taken into account. The theoretical study of a related linear algebraic problem gives general results

Dorothea Bahns, Stefan Waldmann

Localized noncommutative structures for manifolds with connection are constructed based on the use of vertical star products. The model&#39;s main feature is that two points that are far away from each other will not be subject to a deviation from classical geometry while space-time becomes noncommutative for pairs of points that are close to one another.

Niels Jacob, Alexander Potrykus

We suggest to investigate certain non-standard (pseudo-)differential operators in order to construct and to study multi-parameter processes. Our approach will include &#34;classical&#34; multi-parameter Markov processes but will go eventually far beyond.

Pierre-Emmanuel Caprace, Frédéric Haglund

Given a complete CAT(0) space $X$ endowed with a geometric action of a group $\Gamma$, it is known that if $\Gamma$ contains a free abelian group of rank $n$, then $X$ contains a geometric flat of dimension $n$. We prove a converse of this statement in the special case where $X$ is a convex subcomplex of the CAT(0) realization of a Coxeter group $W$, and $\G

Skip Garibaldi, Anne Quéguiner-Mathieu

For simple simply connected algebraic groups of classical type, Merkurjev, Parimala, and Tignol gave a formula for the restriction of the Rost invariant to torsors induced from the center of the group. We complete their results by proving formulas for exceptional groups. Our method is somewhat different and recovers also their formula for classical groups.

Matjaz Konvalinka, Igor Pak

We present several non-commutative extensions of the MacMahon Master Theorem, further extending the results of Cartier-Foata and Garoufalidis-Le-Zeilberger. The proofs are combinatorial and new even in the classical cases. We also give applications to the $β$-extension and Krattenthaler-Schlosser&#39;s $q$-analogue.

Robert Denk, Thomas Krainer

It is shown that an elliptic scattering operator $A$ on a compact manifold with boundary with coefficients in the bounded operators of a bundle of Banach spaces of class (HT) and Pisier&#39;s property $(α)$ has maximal regularity (up to a spectral shift), provided that the spectrum of the principal symbol of $A$ on the scattering cotangent bundle of the mani

Bhaskar Bagchi

There has been a surge of interest of late in an old result of Nyman and Beurling giving a Hilbert space formulation of the Riemann hypothesis. Many authors have contributed to this circle of ideas, culminating in a beautiful refinement due to Baez-Duarte. The purpose of this little survey is to dis-entangle the resulting web of complications, and reveal the

Pablo Arés-Gastesi, Indranil Biswas

The aim here is to continue the investigation in \cite{AB} of Jacobians of a Klein surface and also to correct an error in \cite{AB}.

Taekyun Kim

In this paper, we study a new p-adic q-l-functions and sums of powers.

Yunan Cui, Henryk Hudzik, Narin Petrot, Suthep Suantai

Necessary and sufficient conditions under which the Cesàro--Orlicz sequence space $\cfi$ is nontrivial are presented. It is proved that for the Luxemburg norm, Cesàro--Orlicz spaces $\cfi$ have the Fatou property. Consequently, the spaces are complete. It is also proved that the subspace of order continuous elements in $\cfi$ can be defined in two ways. Fina

Savita Bhatnagar

The aim of this paper is to study the multipliers from $A_{r}(I)$ to $A_{p}(I), r \ne p$, where $I=(0,\infty)$ is the locally compact topological semigroup with multiplication max and usual topology and $A_{r}(I) = \{f \in L_{1}(I)\hbox{:} \hat{f} \in L_{r}(\hat{I})\}$ with norm $|||f|||_{r} = \|f\|_{1} + \|\hat{f}\|_{r}$.

Ravi P Agarwal, Jong Kyu Kim, Donal O&#39;Regan

New fixed point results are presented for ${\cal U}_c^κ(X,X)$ maps in extension type spaces.

Sunil K. Chebolu

We study the triangulated subcategories of compact objects in stable homotopy categories such as the homotopy category of spectra, the derived categories of rings, and the stable module categories of Hopf algebras. In the first part of this thesis we use a K-theory recipe of Thomason to classify these subcategories. This recipe when applied to the category o

Stephen A. Vavasis

We conjecture that the roots of a degree-n univariate complex polynomial are located in a union of n-1 annuli, each of which is centered at a root of the derivative and whose radii depend on higher derivatives. We prove the conjecture for the cases of degrees 2 and 3, and we report on tests with randomly generated polynomials of higher degree. We state two o

E. Buffenoir, Ph. Roche, V. Terras

For a finite dimensional simple Lie algebra g, the standard universal solution R(x) in $U_q(g)^{\otimes 2}$ of the Quantum Dynamical Yang--Baxter Equation can be built from the standard R--matrix and from the solution F(x) in $U_q(g)^{\otimes 2}$ of the Quantum Dynamical coCycle Equation as $R(x)=F^{-1}_{21}(x) R F_{12}(x).$ It has been conjectured that, in

Martin R. Bridson, Daniel Groves

We study the automorphisms ϕof a finitely generated free group F. Building on the train-track technology of Bestvina, Feighn and Handel, we provide a topological representative f:G\to G of a power of ϕthat behaves very much like the realization on the rose of a positive automorphism. This resemblance is encapsulated in the Beaded Decomposition Theorem which

Giuseppe Della Sala, Alberto Saracco

We treat the boundary problem for complex varieties (with isolated singularities) of dimension greater than one, which are contained in a suitable class of strictly pseudoconvex, unbounded domains of C^n.

Matteo Beccaria, Luigi Del Debbio

We consider the operators with highest anomalous dimension $\Delta$ in the compact rank-one sectors $\mathfrak{su}(1|1)$ and $\mathfrak{su}(2)$ of ${\cal N}=4$ super Yang-Mills. We study the flow of $\Delta$ from weak to strong 't Hooft coupling $\lambda$ by solving (i) the all-loop gauge Bethe Ansatz, (ii) the quantum string Bethe Ansatz. The two calculatio

Jose Bernabeu, John Ellis, Nick E. Mavromatos, Dimitri V. Nanopoulos

In this review we first discuss the theoretical motivations for possible CPT violation and deviations from ordinary quantum-mechanical behavior of field-theoretic systems in the context of an extended class of quantum-gravity models. Then we proceed to a description of precision tests of CPT symmetry using mainly neutral kaons. We emphasize the possibly uniq

Patricio Gaete, Clovis Wotzasek

We propose a new Lorentz invariant violating extension for the pure photonic sector of the Standard Model due to the condensation of topological defects in the context of the Julia-Toulouse mechanism. Possible physical consequences leading to direct measurable effects over the confining properties of the elementary particles are explored.

Nick E. Mavromatos

In this talk I review theoretical motivations for possible CPT Violation and deviations from ordinary quantum mechanical behavior of field theoretic systems in some quantum gravity models, and I describe the relevant precision tests using neutral and charged Kaons. I emphasize the possibly unique role of neutral-meson factories in providing specific tests of

M. De Vito, P. Santorelli

By using a constituent quark model we compute the form factors relevant to semileptonic transitions of B mesons into low-lying p-wave charmed mesons. We evaluate the q^2 dependence of these form factors and compare them with other model calculations. The Isgur-Wise functions tau(1/2) and tau(3/2) are also obtained in the heavy quark limit of our results.

Pierre Fayet

Following searches for photinos and very light gravitinos in invisible decays of psi and Upsilon, we discuss new limits on Light Dark Matter and U bosons, from psi and Upsilon decays, as well as rare decays of K+ and invisible decays of pi0, eta and eta&#39; ... . The new limits involving the vector couplings of the U to quarks turn out, not surprisingly, to

S. M. Bilenky

Status of the problem of neutrino masses, mixing and oscillations is discussed. Future perspectives are briefly considered.

H. M. Asatrian, T. Ewerth, A. Ferroglia, P. Gambino

We compute the O(α_s^2) contributions to the photon energy spectrum of the inclusive decay \bar{B} -> X_s γassociated with the magnetic penguin operator O_7. They are an essential part of the ongoing NNLO calculation of this important decay. We use two different methods to evaluate the master integrals, one based on the differential equation approach and the

J. Bechi, R. Casalbuoni, S. De Curtis, D. Dominici

We consider a five dimensional SU(2) gauge theory with fermions in the bulk and with additional SU(2) and U(1) kinetic terms on the branes. The electroweak breaking is obtained by boundary conditions. After deconstruction, fermions in the bulk are eliminated by using their equations of motion. In this way Standard Model fermion mass terms and direct coupling

Frans R. Klinkhamer

A physical mechanism for CPT violation is reviewed, which relies on chiral fermions, gauge interactions, and nontrivial spacetime topology. The nontrivial topology can occur at the very largest scale (e.g., at the &#34;edge&#34; of the universe) or at the very smallest scale (e.g., from a hypothetical spacetime foam). The anomalous effective gauge field acti

B. Aubert et al

We present preliminary results of a search for the decays B+ -> rho+ gamma, B0 -> rho0 gamma, and B0 -> omega gamma. The analysis is based on data containing 347 million BB events recorded with the BaBar detector at the PEP-II B factory. We measure branching fractions of BF(B+ -> rho+ gamma) = (1.06^{+0.35}_{-0.31} +- 0.09) x 10^{-6} and BF(B+ -> rho0 gamma)

The BABAR Collaboration, B. Aubert

We search for the decays B0->rho0rho0, B0->rho0f0, and B0->f0f0 in a sample of about 348 million Upsilon(4S)->BBbar decays collected with the BABAR detector at the PEP-II asymmetric-energy e+e- collider at SLAC. We find evidence for B0->rho0rho0 with 3.0 sigma significance and measure the branching fraction B = (1.16 +0.37-0.36 +-0.27) 10^{-6} and longitudin

The BABAR Collaboration, B. Aubert

We present a measurement of the time-dependent CP-violating asymmetries in B0 -> K0S pi0 decays based on 348 million Y(4S) -> BBbar events collected by the BABAR experiment at the PEP-II asymmetric-energy B Factory at SLAC. We measure the direct CP-violating asymmetry C_{K0S pi0} = 0.20 +/- 0.16 +/- 0.03 and the CP-violating asymmetry in the interference bet

The BABAR Collaboration, B. Aubert

Using 230.2 fb^(-1) of e+e- annihilation data collected with the BABAR detector at and near the peak of the Y(4S) resonance, 489 +/- 55 events containing the pure leptonic decay D_s^+ --> mu^+ nu_mu have been isolated in charm-tagged events. The ratio of partial widths Gamma(D_s^+ --> mu^+ nu_mu)/Gamma(D_s^+ --> phi pi^+) is measured to be 0.143 +/- 0.018 +/

Carsten Schmitz

Results are presented on the inclusive production of isolated prompt photons in deep inelastic scattering with a four-momentum transfer of $Q^2>4 GeV^2$. The cross sections are measured for the transverse momentum range of the photons $3 < E_T^γ< 10 GeV$ and for the pseudorapidity range of the photons $-1.2 < η^γ< 1.8$. They are measured differentially as a

The BABAR Collaboration, B. Aubert

We measure the branching fraction, polarization and CP asymmetry of B+ -> rho+rho0 decays and search for the decay B+ -> rho+f_0(980) based on a data sample of 231.8 million Y(4S)->BB decays collected with the BaBar detector at the SLAC PEP-II asymmetric-energy B factory. In B+ -> rho+rho0 decays we measure B=(16.8+-2.2+-2.3)x10-6, f_L=0.905+-0.042+0.023-0.0

The BABAR Collaboration, B. Aubert

CP violation in B0B0bar mixing is characterized by the value of the parameter |q/p| being different from 1, and the Standard Model predicts this difference to be smaller than 10^{-3}. We present a measurement of this parameter using a partial reconstruction of one of the B mesons in the semileptonic channel D*- l+ nu_l, where only the hard lepton and the sof

The BABAR Collaboration, B. Aubert

We present a search for D0--anti-D0 mixing in the decays D0 --> K+ pi- pi+ pi- using 230.4 fb-1 of data collected with the BaBar detector at the PEP-II e+ e- collider at SLAC. Assuming CP conservation, we measure the time-integrated mixing rate R_M = (0.019 +0.016/-0.015(stat.) +/- 0.002(syst.))%, and R_M < 0.048% at the 95% confidence level. Using a frequen

John D. Barrow, Douglas J. Shaw

We show by using the method of matched asymptotic expansions that a sufficient condition can be derived which determines when a local experiment will detect the cosmological variation of a scalar field which is driving the spacetime variation of a supposed constant of Nature. We extend our earlier analyses of this problem by including the possibility that th

Herbert W. Hamber, Ruth M. Williams

Quantum corrections to the classical field equations, induced by a scale dependent gravitational constant, are analyzed in the case of the static isotropic metric. The requirement of general covariance for the resulting non-local effective field equations puts severe restrictions on the nature of the solutions that can be obtained. In general the existence o

Martin Bojowald

General relativity successfully describes space-times at scales that we can observe and probe today, but it cannot be complete as a consequence of singularity theorems. For a long time there have been indications that quantum gravity will provide a more complete, non-singular extension which, however, was difficult to verify in the absence of a quantum theor

Anirudh Pradhan, S. Otarod

A new class of exact solutions of Einstein&#39;s field equations with perfect fluid for an LRS Bianchi type-I spacetime is obtained by using a time dependent deceleration parameter. We have obtained a general solution of the field equations from which three models of the universe are derived: exponential, polynomial and sinusoidal form respectively. The beha

Benedikt Zeller, Ralf Hiptmair

In computational relativity, critical behaviour near the black hole threshold has been studied numerically for several models in the last decade. In this paper we present a spatial Galerkin method, suitable for finding numerical solutions of the Einstein-Dirac equations in spherically symmetric spacetime (in polar/areal coordinates). The method features exac

Vladimir Vovk

Assuming that the loss function is convex in the prediction, we construct a prediction strategy universal for the class of Markov prediction strategies, not necessarily continuous. Allowing randomization, we remove the requirement of convexity.

Shmuel Friedland, Daniel Levy

We show that the number of $k$-matching in a given undirected graph $G$ is equal to the number of perfect matching of the corresponding graph $G_k$ on an even number of vertices divided by a suitable factor. If $G$ is bipartite then one can construct a bipartite $G_k$. For bipartite graphs this result implies that the number of $k$-matching has a polynomial-

Boris D. Lubachevsky

A computer simulation has to be fast to be helpful, if it is employed to study the behavior of a multicomponent dynamic system. This paper discusses modeling concepts and algorithmic techniques useful for creating such fast simulations. Concrete examples of simulations that range from econometric modeling to communications to material science are used to ill

S. G. Bhongale, S. J. J. M. F. Kokkelmans

We study BCS-BEC crossover in the strongly correlated regime of two component rotating Fermi gases. We predict that the strong correlations induced by rotation will have the effect of modifying the crossover region relative to the non-rotating situation. We show via the two particle correlation function that the crossover smoothly connects the s-wave paired

Rajiv Bhat, B. M. Peden, B. T. Seaman, M. Kramer

Bose gases in rotating optical lattices combine two important topics in quantum physics: superfluid rotation and strong correlations. In this paper, we examine square two-dimensional systems at zero temperature comprised of strongly repulsive bosons with filling factors of less than one atom per lattice site. The entry of vortices into the system is characte

Martin Y. Veillette, Daniel E. Sheehy, Leo Radzihovsky, Victor Gurarie

We study a rotating atomic Fermi gas near a narrow s-wave Feshbach resonance in a uniaxial harmonic trap with frequencies $Ω_\perp$, $Ω_z$. Our primary prediction is the upper-critical angular velocity, $ω_{c2} (δ,T)$, as a function of temperature $T$ and resonance detuning $δ$, ranging across the BEC-BCS crossover. The rotation-driven suppression of superfl

A. A. Aligia

We study the differential conductance, spectral density and magnetization, for a quantum dot coupled to two conducting leads as a function of bias voltage, magnetic field and temperature. The system is modeled with the Anderson model solved using a spin dependent interpolative perturbative approximation in the Coulomb repulsion U that conserves the current.

Chung-Hou Chung, Walter Hofstetter

We study transport through two quantum dots coupled by an RKKY interaction as a function of temperature and magnetic field. By applying the Numerical Renormalization Group (NRG) method we obtain the transmission and the linear conductance. At zero temperature and magnetic field, we observe a quantum phase transition between the Kondo screened state and a loc

Victor Kurasov

The periods after the end of the &#34;primary&#34; nucleation are considered. The approximate analytical description is given. The process is split into several periods which form the loop of evolution.

Kartick Tarafder, Atisdipankar Chakrabarti, Kamal Krishna Saha, Abhijit Mookerjee

In this work we have combined the generalized augmented space method introduced by one of us with the recursion method of Haydock et al (GASR), within the framework of the local density functional based linear muffin-tin orbitals basis (TB-LMTO). Using this we have studied the effect of short-range ordering and clustering on the density of states, optical co

Dale Kitchen, Anthony Richardella, Jian-Ming Tang, Michael E. Flatte

The discovery of ferromagnetism in Mn doped GaAs [1] has ignited interest in the development of semiconductor technologies based on electron spin and has led to several proof-of-concept spintronic devices [2-4]. A major hurdle for realistic applications of (Ga,Mn)As, or other dilute magnetic semiconductors, remains their below room-temperature ferromagnetic

Robert Stadler

The alignment of the Fermi level of a metal electrode within the gap of the highest occupied and lowest unoccupied orbital of a molecule is a key quantity in molecular electronics. Depending on the type of molecule and the interface structure of the junction, it can vary the electron transparency of a gold/molecule/gold junction by at least one order of magn

S. L. Bud&#39;ko, G. M. Schmiedeshoff, P. C. Canfield

We present anisotropic thermal expansion measurements on single crystalline ErNi2B2C. All three, superconducting, antiferromagnetic and weak ferromagnetic phase transitions are unambiguously distinguished in the data. Anisotropic uniaxial pressure dependencies of the transitions are estimated based on the Ehrenfest relation, leading to a conclusion, in parti

B. I. Belevtsev, G. A. Zvyagina, K. R. Zhekov, I. G. Kolobov

The ultrasonic properties of La$_{1-x}$Ca$_{x}$MnO$_{3}$ ($x\approx 0.25$) with the Curie temperature $T_C$ about 200 K are studied. Temperature dependences of longitudinal and transverse sound velocities were measured in zero magnetic field and for different constant magnetic fields as well. The ultrasonic study is supported by magnetic, resistive, magnetor

J. Hickford, R. Jones, S. Courrech du Pont, J. Eggers

We study the formation of knots on a macroscopic ball-chain, which is shaken on a horizontal plate at 12 times the acceleration of gravity. We find that above a certain critical length, the knotting probability is independent of chain length, while the time to shake out a knot increases rapidly with chain length. The probability if finding a knot after a cer

A. Weichselbaum, S. E. Ulloa

We investigate the tunability of electrostatic coupling between solid state quantum dots as building blocks for quantum bits. Specifically, our analysis is based upon two-dimensional electron systems (2DEG) and depletion by top gates. We are interested in whether the Coulomb interaction between qubits can be tuned by electrical means using screening effects.

I. V. Yurkevich, I. V. Lerner, A. S. Stepanenko, C. C. Constantinou

We suggest a model for data losses in a single node of a packet-switched network (like the Internet) which reduces to one-dimensional discrete random walks with unusual boundary conditions. The model shows critical behavior with an abrupt transition from exponentially small to finite losses as the data arrival rate increases. The critical point is characteri

M. Bonura, A. Agliolo Gallitto, M. Li Vigni

We discuss the hysteretic behavior of the field-induced variations of the microwave surface resistance in superconductors in the critical state. Measurements have been performed in a bulk sample of Nb and a powdered one at different values of the temperature. We discuss a model, based on the Coffey and Clem theory, in which we take into account the flux dist

S. El Shawish, J. Bonca

Using variational algorithm on an infinite Shastry-Sutherland (SS) lattice we show that the introduction of a static nonmagnetic impurity into a dimerized ground state leads to a formation of a small, localized spin polaron surrounding the impurity site. Due to a particular symmetry of the SS lattice, the polaron is extremely anisotropic with a short spatial

Peter Samuelsson, Claudio Verdozzi

We investigate the two-particle spin entanglement in magnetic nanoclusters described by the periodic Anderson model. An entanglement phase diagram is obtained, providing a novel perspective on a central property of magnetic nanoclusters, namely the temperature dependent competition between local Kondo screening and nonlocal Ruderman-Kittel-Kasuya-Yoshida spi

V. S. Poghosyan, V. B. Priezzhev

We consider the totally asymmetric exclusion process on a ring in discrete time with the backward-ordered sequential update and particle-dependent hopping probabilities. Using a combinatorial treatment of the Bethe ansatz, we derive the determinant expression for the non-stationary probability of transitions between particle configurations. In the continuous

Ronny Thomale, Dirk Schuricht, Martin Greiter

We construct the explicit two-holon eigenstates of the SU(2) Kuramoto-Yokoyama model at the level of explicit wave functions. We derive the exact energies and obtain the individual holon momenta, which are quantized according to the half-Fermi statistics of the holons.

Dario Benedetto, Emanuele Caglioti, Davide Gabrielli

We present rigorous results on some open questions on NSRPS, non sequential recursive pairs substitution method (see Grassberger in \cite{G}). In particular, starting from the action of NSRPS on finite strings we define a corresponding natural action on measures and we prove that the iterated measure becomes asymptotically Markov. This certify the effectiven

A. Singha, A. Roy, D. Kabiraj, D. Kanjilal

In spite of several articles, the origin of visible luminescence from germanium nanocrystals in SiO$_2$ matrix is controversial even today. Some authors attribute the luminescence to quantum confinement of charge carriers in these nanocrystals. On the other hand, surface or defect states formed during the growth process, have also been proposed as the source

Hiroshi Watanabe, Hiroto Kobayashi

Ergodicity of the systems with Nosé-Hoover thermostat are studied. The dynamics of the heatbath variables are investigated and they can be periodic when the system has quick oscillation. The periodic behaviour of them causes the system to lose its ergodicity. The kinetic-moments method is also studied, and the heatbath variables in this method are found to b

D. Natelson, B. H. Hamadani, J. W. Ciszek, D. A. Corley

Contact resistances often contribute significantly to the overall device resistance in organic field-effect transistors (OFETs). Understanding charge injection at the metal-organic interface is critical to optimizing OFET device performance. We have performed a series of experiments using bottom-contact poly(3-hexylthiophene) (P3HT) OFETs in the shallow chan

Johannes Frantti

The issues related to the structure refinement of Pb(ZrxTi1-x)O3 (PZT) solid solutions are discussed. Particular attention is paid on the modelling of the co-existing phases in the vicinity of the morphotropic phase boundary (MPB), where local symmetry is often significantly lower than the average symmetry. According to recent studies, two-phase co-existence

S. V. Isakov, S. Wessel, R. G. Melko, K. Sengupta

Using large scale quantum Monte Carlo simulations and dual vortex theory we analyze the ground state phase diagram of hard-core bosons on the kagome lattice with nearest neighbor repulsion. In contrast to the case of a triangular lattice, no supersolid emerges for strong interactions. While a uniform superfluid prevails at half-filling, two novel solid phase

Kazumoto Iguchi, Shuichi Kinoshita, Hiroaki S. Yamada

We study the Boolean dynamics of the &#34;quenched&#34; Kauffman models with a directed scale-free network, comparing with that of the original directed random Kauffman networks and that of the directed exponential-fluctuation networks. We have numerically investigated the distributions of the state cycle lengths and its changes as the network size $N$ and t