Results for "Mendeli H. Vainstein"

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Disordered Environments in Spatial GamesJul 27 2001The Prisoner's dilemma is the main game theoretical framework in which the onset and maintainance of cooperation in biological populations is studied. In the spatial version of the model, we study the robustness of cooperation in heterogeneous ecosystems ... More
Spatial social dilemmas: dilution, mobility and grouping effects with imitation dynamicsNov 24 2015We present an extensive, systematic study of the Prisoner's Dilemma and Snowdrift games on a square lattice under a synchronous, noiseless imitation dynamics. We show that for both the occupancy of the network and the (random) mobility of the agents there ... More
Percolation and cooperation with mobile agents: Geometric and strategy clustersAug 26 2014We study the conditions for persistent cooperation in an off-lattice model of mobile agents playing the Prisoner's Dilemma game with pure, unconditional strategies. Each agent has an exclusion radius rP, which accounts for the population viscosity, and ... More
Anomalous DiffusionMay 02 2008May 03 2008Recent investigations call attention to the dynamics of anomalous diffusion and its connection with basic principles of statistical mechanics. We present here a short review of those ideas and their implications.
On the Modeling of Droplet Evaporation on Superhydrophobic SurfacesOct 14 2015When a drop of water is placed on a rough surface, there are two possible extreme regimes of wetting: the one called Cassie-Baxter (CB) with air pockets trapped underneath the droplet and the one characterized by the homogeneous wetting of the surface, ... More
Spatio-temporal conjecture for diffusionFeb 01 2005We present here a conjecture about the equivalence between the noise density of states of a system governed by a generalized Langevin equation and the fluctuation in the energy density of states in a Hamiltonian system. We present evidence of this for ... More
Does mobility decrease cooperation?Aug 04 2006Sep 12 2006We explore the minimal conditions for sustainable cooperation on a spatially distributed population of memoryless, unconditional strategies (cooperators and defectors) in presence of unbiased, non contingent mobility in the context of the Prisoner's Dilemma ... More
Heterogeneities in systems with quenched disorderApr 10 2003We study the strong role played by structural (quenched) heterogeneities on static and dynamic properties of the Frustrated Ising Lattice Gas in two dimensions, already in the liquid phase. Differently from the dynamical heterogeneities observed in other ... More
Random mobility and spatial structure often enhance cooperationSep 09 2008The effects of an unconditional move rule in the spatial Prisoner's Dilemma, Snowdrift and Stag Hunt games are studied. Spatial structure by itself is known to modify the outcome of many games when compared with a randomly mixed population, sometimes ... More
Khinchin theorem and anomalous diffusionOct 31 2008Dec 10 2008A recent paper [M. H. Lee, Phys. Rev. Lett. 98, 190601 (2007)] has called attention to the fact that irreversibility is a broader concept than ergodicity, and that therefore the Khinchin theorem [A. I. Khinchin, Mathematical Foundations of Statistical ... More
Non-exponential relaxation for anomalous diffusionJan 21 2005May 04 2006We study the relaxation process in normal and anomalous diffusion regimes for systems described by a generalized Langevin equation (GLE). We demonstrate the existence of a very general correlation function which describes the relaxation phenomena. Such ... More
Mixing, ergodicity and slow relaxation phenomenaOct 10 2006Oct 20 2006Investigations on diffusion in systems with memory [I.V.L. Costa, R. Morgado, M.V.B.T. Lima, F.A. Oliveira, Europhys. Lett. 63 (2003) 173] have established a hierarchical connection between mixing, ergodicity, and the fluctuation-dissipation theorem (FDT). ... More
Anomalous diffusion: A basic mechanism for the evolution of inhomogeneous systemsFeb 08 2019In this article we review classical and recent results in anomalous diffusion and provide mechanisms useful for the study of the fundamentals of certain processes, mainly in condensed matter physics, chemistry and biology. Emphasis will be given to some ... More
A Simple Non-Markovian Computational Model of the Statistics of Soccer Leagues: Emergence and Scaling effectsJul 08 2012We propose a novel algorithm that outputs the final standings of a soccer league, based on a simple dynamics that mimics a soccer tournament. In our model, a team is created with a defined potential(ability) which is updated during the tournament according ... More
Mixing, Ergodicity and the Fluctuation-Dissipation Theorem in complex systemsJan 19 2005Complex systems such as glasses, gels, granular materials, and systems far from equilibrium exhibit violation of the ergodic hypothesis (EH) and of the fluctuation-dissipation theorem (FDT). Recent investigations in systems with memory have established ... More
Protein motors induced enhanced diffusion in intracellular transportFeb 04 2009Diffusion of transported particles in the intracellular medium is described by means of a generalized diffusion equation containing forces due to the cytoskeleton network and to the protein motors. We find that the enhanced diffusion observed in experiments ... More
Entropic Stochastic ResonanceJul 16 2008We present a novel scheme for the appearance of Stochastic Resonance when the dynamics of a Brownian particle takes place in a confined medium. The presence of uneven boundaries, giving rise to an entropic contribution to the potential, may upon application ... More
Entropy, non-ergodicity and non-Gaussian behaviour in ballistic transportJan 30 2007Ballistic transportation introduces new challenges in the thermodynamic properties of a gas of particles. For example, violation of mixing, ergodicity and of the fluctuation-dissipation theorem may occur, since all these processes are connected. In this ... More
Stochastic description of the dynamics of the random-exchange Heisenberg chainAug 26 2003May 05 2006We study the diffusion process in a Heisenberg chain with correlated spatial disorder, with a power spectrum in the momentum space behaving as $k^{-\beta}$, using a stochastic description. It establishes a direct connection between the fluctuation in ... More
Emergent states in dense systems of active rods: from swarming to turbulenceApr 02 2012Dense suspensions of self-propelled rod-like particles exhibit a fascinating variety of non-equilibrium phenomena. By means of computer simulations of a minimal model for rigid self-propelled colloidal rods with variable shape we explore the generic diagram ... More
Rhythmic cluster generation in strongly driven colloidal dispersionsJun 28 2006We study the response of a nematic colloidal dispersion of rods to a driven probe particle which is dragged with high speed through the dispersion perpendicular to the nematic director. In front of the dragged particle, clusters of rods are generated ... More
Aggregation of self-propelled colloidal rods near confining wallsSep 03 2008Non-equilibrium collective behavior of self-propelled colloidal rods in a confining channel is studied using Brownian dynamics simulations and dynamical density functional theory. We observe an aggregation process in which rods self-organize into transiently ... More
Thermodynamical description of modified generalized Chaplygin gas model of dark energyApr 10 2015May 17 2016We consider a universe filled by a modified generalized Chaplygin gas together with a pressureless dark matter component. We get a thermodynamical interpretation for the modified generalized Chaplygin gas confined to the apparent horizon of FRW universe, ... More
Asymptotic function for multi-growth surfaces using power-law noiseNov 06 2002Numerical simulations are used to investigate the multiaffine exponent $\alpha_q$ and multi-growth exponent $\beta_q$ of ballistic deposition growth for noise obeying a power-law distribution. The simulated values of $\beta_q$ are compared with the asymptotic ... More
Comment on `Mathematical structure of the three-dimensional (3D) Ising model'Jul 06 2013The review paper by Zhang Zhi-Dong contains many errors and is based on several earlier works that are equally wrong.
Theory of the Hall Coefficient and the Resistivity on the Layered Organic Superconductors κ-(BEDT-TTF)Nov 20 2000Feb 22 2001In the organic superconducting \kappa-(BEDT-TTF) compounds, various transport phenomena exhibit striking non-Fermi liquid behaviors, which should be the important clues to understanding the electronic state of this system. Especially, the Hall coefficient ... More
Scalings between Physical and their Observationally related Quantities of Merger RemnantsSep 07 2005We present scaling relations between the virial velocity (V) and the one-dimensional central velocity dispersion (Sig0); the gravitational radius (Rv) and the effective radius (Re); and the total mass (M) and the luminous mass (ML) found in N-body simulations ... More
An ansatz for the nonlinear Demkov-Kunike problem for cold molecule formationFeb 24 2010We study nonlinear mean-field dynamics of ultracold molecule formation in the case when the external field configuration is defined by the level-crossing Demkov-Kunike model, characterized by a bell-shaped coupling and finite variation of the detuning. ... More
Study of $Λ$ hypernuclei in the quark mean field modelApr 24 2001Jul 11 2001We extend the quark mean field model to the study of $\Lambda$ hypernuclei. Without adjusting parameters, the properties of $\Lambda$ hypernuclei can be described reasonably well. The small spin-orbit splittings for $\Lambda$ in hypernuclei are achieved, ... More
Superradiant cascade emissions in an atomic ensemble via four-wave mixingJan 21 2015May 04 2015We investigate superradiant cascade emissions from an atomic ensemble driven by two-color classical fields. The correlated pair of photons (signal and idler) is generated by adiabatically driving the system with large-detuned light fields via four-wave ... More
Spectral analysis for cascade-emission-based quantum communication in atomic ensemblesMar 11 2014The ladder configuration of atomic levels provides a source for telecom photons (signal) from the upper atomic transition. \ For rubidium and cesium atoms, the signal field has the range around 1.3-1.5 $\mu$m that can be coupled to an optical fiber and ... More
Positive-P phase space method simulation in superradiant emission from a cascade atomic ensembleJan 12 2012The superradiant emission properties from an atomic ensemble with cascade level configuration is numerically simulated. The correlated spontaneous emissions (signal then idler fields) are purely stochastic processes which are initiated by quantum fluctuations. ... More
Correlation Energy Estimators based on Møller-Plesset Perturbation TheoryMar 05 1996Some methods for the convergence acceleration of the M{\o}ller-Plesset perturbation series for the correlation energy are discussed. The order-by-order summation is less effective than the Feenberg series. The latter is obtained by renormalizing the unperturbed ... More
Surface anisotropy in nanomagnets: transverse or Néel ?Jul 17 2003Mar 31 2004Through the hysteresis loop and magnetization spatial distribution we study and compare two models for surface anisotropy in nanomagnets: a model with transverse anisotropy axes and N\'eel's model. While surface anisotropy in the transverse model induces ... More
String-Scale BaryogenesisMar 25 1997Mar 26 1997Baryogenesis scenarios at the string scale are considered. The observed baryon to entropy ratio, $n_B /s \sim 10^{-10}$, can be explained in these scenarios.
Thermodynamic of universe with a varying dark energy componentMay 04 2015Aug 03 2015We consider a FRW universe filled by a dark energy candidate together with other possible sources which may include the baryonic and non-baryonic matters. Thereinafter, we consider a situation in which the cosmos sectors do not interact with each other. ... More
Rejoinder on "Conjectures on exact solution of three-dimensional (3D) simple orthorhombic Ising lattices"Jan 19 2009Mar 30 2009It is shown that the arguments in the reply of Z.-D. Zhang (arXiv:0812.0194) to the comment arXiv:0811.1802 defending his conjectures in arXiv:0705.1045 are invalid. His conjectures have been thoroughly disproved.
The two-fermion vector potential of constraint theory from Feynman diagramsOct 16 1995The relativistic fermion-antifermion bound state vector potential of constraint theory is calculated, in perturbation theory, by means of the Lippmann-Schwinger type equation that relates it to the scattering amplitude. Leading contributions of n-photon ... More
Energy and decay width of the pi-K atomMay 24 2006The energy and decay width of the pi-K atom are evaluated in the framework of the quasipotential-constraint theory approach. The main electromagnetic and isospin symmetry breaking corrections to the lowest-order formulas for the energy shift from the ... More
Whitham Prepotential and SuperpotentialDec 30 2003Jan 24 2004N=2 supersymmetric U(N) Yang-Mills theory softly broken to N=1 by the superpotential of the adjoint scalar fields is discussed from the viewpoint of the Whitham deformation theory for prepotential. With proper identification of the superpotential we derive ... More
N=8 matter coupled AdS_3 supergravitiesJun 18 2001Following the recent construction of maximal (N=16) gauged supergravity in three dimensions, we derive gauged D=3, N=8 supergravities in three dimensions as deformations of the corresponding ungauged theories with scalar manifolds SO(8,n)/(SO(8)x SO(n)). ... More
Maximal gauged supergravity in three dimensionsOct 11 2000Jan 07 2001We construct maximally supersymmetric gauged N=16 supergravity in three dimensions, thereby obtaining an entirely new class of AdS supergravities. These models are not derivable from any known higher-dimensional theory, indicating the existence of a new ... More
Effect of size polydispersity on the pitch of nanorod cholestericsMar 14 2019Many nanoparticle-based chiral liquid crystals are composed of polydisperse rod-shaped particles with considerable spread in size or shape, affecting the mesoscale chiral properties in, as yet, unknown ways. Using an algebraic interpretation of Onsager-Straley ... More
Erroneous solution of three-dimensional (3D) simple orthorhombic Ising latticesSep 04 2012Jun 18 2013The first paper is an invited comment on arXiv:1110.5527 presented at Hypercomplex Seminar 2012 and on sixteen earlier published papers by Zhidong Zhang and Norman H. March. All these works derive from an erroneous solution of the three-dimensional Ising ... More
Onsager algebra and cluster XY-models in a transverse magnetic fieldOct 10 2017Nov 09 2017The correlation functions of certain $n$-cluster XY models are explicitly expressed in terms of those of the standard Ising chain in transverse field.
AdS/CFT correspondence in the Euclidean contextNov 02 2006May 23 2007We study two possible prescriptions for AdS/CFT correspondence by means of functional integrals. The considerations are non-perturbative and reveal certain divergencies which turn out to be harmless, in the sense that reflection-positivity and conformal ... More
Analysis of the thermal cross section of the capture reaction 13C(n,gamma)14COct 02 1997We investigate the thermal cross section of the reaction 13C(n,gamma)14}C which takes place in the helium burning zones of red giant star as well as in the nucleosynthesis of Inhomogeneous Big Bang models. We find that we can reproduce the experimentally ... More
Continuous Fourier Transform: A practical approach for truncated signals and suggestions for improvements in thermographyJul 02 2019The fundamentals of Fourier Transform are presented, with analytical solutions derived for Continuous Fourier Transform (CFT) of truncated signals, to benchmark against Fast Fourier Transform (FFT). Certain artifacts from FFT were identified for decay ... More
The relativistic two-body potentials of constraint theory from summation of Feynman diagramsFeb 07 1996The relativistic two-body potentials of constraint theory for systems composed of two spin-0 or two spin-1/2 particles are calculated, in perturbation theory, by means of the Lippmann-Schwinger type equation that relates them to the scattering amplitude. ... More
Cooperative single-photon subradiant states in a three-dimensional atomic arrayJun 21 2016We propose a complete superradiant and subradiant states that can be manipulated and prepared in a three-dimensional atomic array. These subradiant states can be realized by absorbing a single photon and imprinting the spatially-dependent phases on the ... More
Application of the Limit Cycle Model to Star Formation Histories in Spiral Galaxies: Variation among Morphological TypesMay 04 2000We propose a limit-cycle scenario of star formation history for any morphological type of spiral galaxies. It is known observationally that the early-type spiral sample has a wider range of the present star formation rate (SFR) than the late-type sample. ... More
The size-extensitivity of correlation energy estimators based on effective characteristic polynomialsApr 08 1997Estimators $\Pi n$ for the correlation energy can be computed as roots of effective characteristic polynomials of degree $n$. The coefficients of these polynomials are derived from the terms of the perturbation series of the energy. From a fourth-order ... More
Integrability and Canonical Structure of d=2, N=16 SupergravityApr 23 1998Jul 01 1998The canonical formulation of d=2, N=16 supergravity is presented. We work out the supersymmetry generators (including all higher order spinor terms) and the N=16 superconformal constraint algebra. We then describe the construction of the conserved non-local ... More
Effects of Spin Fluctuations in Quasi-One-Dimensional Organic SuperconductorsMay 05 1999We study the electronic states of quasi-one-dimensional organic conductors using the single band Hubbard model at half-filling. We treat the effects of the on-site Coulomb interaction by the fluctuation-exchange (FLEX) method, and calculate the phase ... More
On the extrapolation of perturbation seriesDec 21 2002We discuss certain special cases of algebraic approximants that are given as zeroes of so-called "effective characteristic polynomials" and their generalization to a multiseries setting. These approximants are useful for the convergence acceleration or ... More
A focusable, convergent fast-electron beam from ultra-high-intensity laser-solid interactionsJan 29 2015A novel scheme for the creation of a convergent, or focussing, fast-electron beam generated from ultra-high-intensity laser-solid interactions is described. Self-consistent particle-in-cell simulations are used to demonstrate the efficacy of this scheme ... More
Quark mean field model for nuclear matter and finite nucleiNov 15 1999We study nuclear matter and finite nuclei in terms of the quark mean field (QMF) model, in which we describe the nucleon using the constituent quark model. The meson mean fields, in particular the sigma meson, created by other nucleons act on quarks inside ... More
Molecular dynamics simulation of aging in amorphous silicaDec 06 1999By means of molecular dynamics simulations we examine the aging process of a strong glass former, a silica melt modeled by the BKS potential. The system is quenched from a temperature above to one below the critical temperature, and the potential energy ... More
Boundary blow-up solutions of elliptic equations involving regional fractional LaplacianFeb 09 2016In this paper, we study existence of boundary blow-up solutions for elliptic equations involving regional fractional Laplacian. We also discuss the optimality of our results.
A 5D noncompact Kaluza -Klein cosmology in the presence of Null perfect fluidMay 18 2010Jun 08 2011For the description of the early inflation, and acceleration expansion of the Universe, compatible with observational data, the 5D noncompact Kaluza--Klein cosmology is investigated. It is proposed that the 5D space is filled with a null perfect fluid, ... More
Schwinger-Dyson and Large $N_{c}$ Loop Equation for Supersymmetric Yang-Mills TheoryApr 04 1996We derive an infinite sequence of Schwinger-Dyson equations for $N=1$ supersymmetric Yang-Mills theory. The fundamental and the only variable employed is the Wilson-loop geometrically represented in $N=1$ superspace: it organizes an infinite number of ... More
The infinite mass limit of the two-particle Green's function in QEDApr 07 1997The behavior of the two-particle Green's function in QED is analyzed in the limit when one of the particles becomes infinitely massive. It is found that the dependences of the Green's function on the relative times of the ingoing and outgoing particles ... More
Incorporation of anomalous magnetic moments in the two-body relativistic wave equations of constraint theoryJun 19 1996Using a Dirac-matrix substitution rule, applied to the electric charge, the anomalous magnetic moments of fermions are incorporated in local form in the two-body relativistic wave equations of constraint theory. The structure of the resulting potential ... More
Quantum-coherence-enhanced subradiance in a chiral-coupled atomic chainMar 13 2019We theoretically study the quantum-coherence-enhanced subradiance in a chiral-coupled atomic chain with nonreciprocal decay channels. The collective radiation in this one-dimensional (1D) nanophotonics system results from the resonant dipole-dipole interactions ... More
The Early History of the Integrable Chiral Potts Model and the Odd-Even ProblemNov 26 2015Jan 18 2016In the first part of this paper I shall discuss the round-about way of how the integrable chiral Potts model was discovered about 30 years ago. As there should be more higher-genus models to be discovered, this might be of interest. In the second part ... More
Composite Pulses in N-level Systems with SU(2) Symmetry and their Geometrical Representation on the Majorana SphereAug 22 2017High fidelity and robustness in population inversion is very desirable for many quantum control applications. We expand composite pulse schemes developed for two-level dynamics, and present an analytic solution for the coherent evolution of an N-level ... More
An indefinite metric model for interacting quantum fields with non-stationary background gravitationAug 25 2004We consider a relativistic Ansatz for the vacuum expectation values (VEVs) of a quantum field on a globally hyperbolic space-time which is motivated by certain Euclidean field theories. The Yang-Feldman asymptotic condition w.r.t. a "in"-field in a quasi-free ... More
Series Prediction based on Algebraic ApproximantsJul 12 2011It is described how the Hermite-Pad\'e polynomials corresponding to an algebraic approximant for a power series may be used to predict coefficients of the power series that have not been used to compute the Hermite-Pad\'e polynomials. A recursive algorithm ... More
On pseudo B-Weyl operators and generalized Drazin invertibility for operator matricesMar 23 2015We introduce a new class which generalizes the class of B-Weyl operators. We say that $T\in L(X)$ is pseudo B-Weyl if $T=T_1\oplus T_2$ where $T_1$ is a Weyl operator and $T_2$ is a quasi-nilpotent operator. We show that the corresponding pseudo B-Weyl ... More
Wave-Packet Scattering off the Kink-SolutionJun 17 2011Jul 20 2011We investigate the propagation of a wave--packet in the $\phi^4$ model. We solve the time-dependent equation of motion for two distinct initial conditions: The wave-packet in a trivial vacuum background and in the background of the kink soliton solution. ... More
How to capture active particlesFeb 01 2012For many applications, it is important to catch collections of autonomously navigating microbes and man-made microswimmers in a controlled way. Here we propose an efficient trap to collectively capture self-propelled colloidal rods. By means of computer ... More
Gauge transformations in relativistic two-particle constraint theorySep 16 1996Using connection with quantum field theory, the infinitesimal covariant abelian gauge transformation laws of relativistic two-particle constraint theory wave functions and potentials are established and weak invariance of the corresponding wave equations ... More
Relativistic effects in the pionium lifetimeJun 23 1997The pionium decay width is evaluated in the framework of chiral perturbation theory and the relativistic bound state formalism of constraint theory. Corrections of order O(\alpha) are calculated with respect to the conventional lowest-order formula, in ... More
Comment on "Conjectures on exact solution of three-dimensional (3D) simple orthorhombic Ising lattices" [arXiv:0705.1045]Nov 12 2008Nov 22 2008It is shown that a recent article by Z.-D. Zhang [arXiv:0705.1045] is in error and violates well-known theorems.
Entropy of entanglement in continuous frequency space of the biphoton state from multiplexed cold atomic ensemblesJan 05 2016We consider a scheme of multiplexed cold atomic ensembles that generate a frequency-entangled biphoton state with controllable entropy of entanglement. The biphoton state consists of a telecommunication photon (signal) immediately followed by an infrared ... More
A nontrivial solvable noncommutative φ^3 model in 4 dimensionsMar 07 2006May 24 2006We study the quantization of the noncommutative selfdual \phi^3 model in 4 dimensions, by mapping it to a Kontsevich model. The model is shown to be renormalizable, provided one additional counterterm is included compared to the 2-dimensional case which ... More
Renormalization of the noncommutative phi^3 model through the Kontsevich modelDec 16 2005We point out that the noncommutative selfdual phi^3 model can be mapped to the Kontsevich model, for a suitable choice of the eigenvalues in the latter. This allows to apply known results for the Kontsevich model to the quantization of the field theory, ... More
Transition Amplitudes within the Stochastic Quantization SchemeSep 30 1993Quantum mechanical transition amplitudes are calculated within the stochastic quantization scheme for the free nonrelativistic particle, the harmonic oscillator and the nonrelativistic particle in a constant magnetic field; we close with free Grassmann ... More
Superradiant laser: Effect of long-ranged dipole-dipole interactionSep 02 2016We theoretically investigate the effect of long-ranged dipole-dipole interaction (LRDDI) on a superradiant laser (SL). This effect is induced from the atom-photon interaction in the dissipation process. In the bad-cavity limit usually performed to initiate ... More
Supereigenvalue Model and Dijkgraaf-Vafa ProposalApr 22 2003We present a variant of the supereigenvalue model proposed before by Alvarez-Gaume, Itoyama, Manes, and Zadra. This model derives a set of three planar loop equations which takes the same form as the set of three anomalous Ward-Takahashi identities on ... More
On K(E_9)Jul 08 2004We study the maximal compact subgroup K(E_9) of the affine Lie group E_9(9) and its on-shell realization as an R symmetry of maximal N=16 supergravity in two dimensions. We first give a rigorous definition of the group K(E_9), which lives on the double ... More
Compact and Noncompact Gauged Maximal Supergravities in Three DimensionsMar 06 2001Apr 21 2001We present the maximally supersymmetric three-dimensional gauged supergravities. Owing to the special properties of three dimensions -- especially the on-shell duality between vector and scalar fields, and the purely topological character of (super)gravity ... More
A Simple Method to Reduce Thermodynamic Derivatives by ComputerJan 09 2014Studies in thermodynamics often require the reduction of some first or second order partial derivatives in terms of a smaller basic set. A simple algorithm to perform such a reduction is presented here, together with a review of earlier related works. ... More
Independent Component Analysis of Spatiotemporal ChaosMay 13 2005Two types of spatiotemporal chaos exhibited by ensembles of coupled nonlinear oscillators are analyzed using independent component analysis (ICA). For diffusively coupled complex Ginzburg-Landau oscillators that exhibit smooth amplitude patterns, ICA ... More
Variational Calculation of Effective Classical Potential at $T \neq 0$ to Higher OrdersApr 16 1995Using the new variational approach proposed recently for a systematic improvement of the locally harmonic Feynman-Kleinert approximation to path integrals we calculate the partition function of the anharmonic oscillator for all temperatures and coupling ... More
Pentaquark $Θ^+$ in nuclear matter and $Θ^+$ hypernucleiOct 17 2004Jul 05 2005We study the properties of the $\Theta^+$ in nuclear matter and $\Theta^+$ hypernuclei within the quark mean-field (QMF) model, which has been successfully used for the description of ordinary nuclei and $\Lambda$ hypernuclei. With the assumption that ... More
Scalar Levin-Type Sequence TransformationsMay 22 2000Sequence transformations are important tools for the convergence acceleration of slowly convergent scalar sequences or series and for the summation of divergent series. Transformations that depend not only on the sequence elements or partial sums $s_n$ ... More
Weak Quantum Theory: Complementarity and Entanglement in Physics and BeyondApr 23 2001Nov 21 2001The concepts of complementarity and entanglement are considered with respect to their significance in and beyond physics. A formally generalized, weak version of quantum theory, more general than ordinary quantum theory of material systems, is outlined ... More
Characterizing arbitrarily slow convergence in the method of alternating projectionsOct 12 2007In 1997, Bauschke, Borwein, and Lewis have stated a trichotomy theorem that characterizes when the convergence of the method of alternating projections can be arbitrarily slow. However, there are two errors in their proof of this theorem. In this note, ... More
The System of Multi Color-flux-tubes in the Dual Ginzburg-Landau TheoryFeb 27 1996We study the system of multi color-flux-tubes in terms of the dual Ginzburg -Landau theory. We consider two ideal cases, where the directions of all the color-flux-tubes are the same in one case and alternative in the other case for neighboring flux-tubes. ... More
Abrupt Emergence of Pressure-Induced Superconductivity of 34 K in SrFe2As2: A Resistivity Study under PressureOct 27 2008Nov 19 2008We report resistivity measurement under pressure in single crystals of SrFe_2As_2, which is one of the parent materials of Fe-based superconductors. The structural and antiferromagnetic (AFM) transition of T_0 = 198 K at ambient pressure is suppressed ... More
Feynman graphs for non-Gaussian measuresJan 12 2005Nov 30 2006Partition- and moment functions for a general (not necessarily Gaussian) functional measure that is perturbed by a Gibbs factor are calculated using generalized Feynman graphs. From the graphical calculus, a new notion of Wick ordering arises, that coincides ... More
Feynman graph representation of the perturbation series for general functional measuresAug 20 2004A representation of the perturbation series of a general functional measure is given in terms of generalized Feynman graphs and -rules. The graphical calculus is applied to certain functional measures of L\'evy type. A graphical notion of Wick ordering ... More
Asymptotic Analysis of High-Contrast Phononic Crystals and a Criterion for the Band-Gap OpeningSep 30 2006We investigate the band-gap structure of the frequency spectrum for elastic waves in a high-contrast, two-component periodic elastic medium. We consider two-dimensional phononic crystals consisting of a background medium which is perforated by an array ... More
The nature of the line profile variability in the spectrum of the massive binary HD 152219May 08 2009Jun 10 2009HD 152219 is a massive binary system with O9.5 III + B1-2 V/III components and a short orbital period of 4.2 d. Its primary component further displays clear line profile variability (LPV). The primary component being located within the pulsational instability ... More
Exploring the cooperative regimes in a model of agents without memory or "tags": indirect reciprocity vs. selfish incentivesNov 15 2002The self-organization in cooperative regimes in a simple mean-field version of a model based on "selfish" agents which play the Prisoner's Dilemma (PD) game is studied. The agents have no memory and use strategies not based on direct reciprocity nor 'tags'. ... More
Lagrangian Description, Symplectic Structure, and Invariants of 3D Fluid FlowMar 24 1997Three dimensional unsteady flow of fluids in the Lagrangian description is considered as an autonomous dynamical system in four dimensions. The condition for the existence of a symplectic structure on the extended space is the frozen field equations of ... More
Stiff quantum polymersOct 19 2009At ultralow temperatures, polymers exhibit quantum behavior, which is calculated here for the second and fourth moments of the end-to-end distribution in the large-stiffness regime. The result should be measurable for polymers in wide optical traps.
Stiff Quantum PolymersJan 02 2007May 01 2007At ultralow temperatures, polymers exhibit quantum behavior, which is calculated here for the moments <R^2> and <R^4> of the end-to-end distribution in the large-stiffness regime. The result should be measurable for polymers in wide optical traps.
Experimental Test for Absence of R-Term in Schroedinger Equation in Curved SpaceOct 29 2000Nov 12 2000We point out that the presence of a term proportional to the scalar curvature in the Schroedinger equation in curved space can easily be detected in atomic spectra with Russel-Saunders coupling by a violation of the Lande interval rule for adjacent levels ... More