Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics最新文献

{"title":"Stochastic resonance without an external periodic drive in a simple prey-predator model","authors":"Rai,&nbsp;Singh","doi":"10.1103/physreve.62.8804","DOIUrl":"https://doi.org/10.1103/physreve.62.8804","url":null,"abstract":"<p><p>We have investigated the effect of noise on a simple prey-predator model where the oscillations are triggered by the internal dynamics of the system without the aid of any external periodic drive. We report the occurrence of stochastic resonancelike behavior in this system, which does not have a threshold or a potential barrier, in the absence of an external drive.</p>","PeriodicalId":20079,"journal":{"name":"Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics","volume":"62 6 Pt B","pages":"8804-7"},"PeriodicalIF":0.0,"publicationDate":"2000-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1103/physreve.62.8804","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21960138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Perturbation theory for the kink of the sine-gordon equation","authors":"Tang,&nbsp;Wang","doi":"10.1103/physreve.62.8842","DOIUrl":"https://doi.org/10.1103/physreve.62.8842","url":null,"abstract":"<p><p>A singular perturbation theory is developed to investigate the kink propagating in systems governed by the sine-Gordon equation with perturbations. The outstanding characteristic of the present theory lies in that the dynamic equation and the dispersive wave as well as the \"translation mode\" are consistently determined in a natural manner, involving no sophisticated derivations pertaining to the inverse scattering transform. A distinct and strict linearization for the subject is introduced. Some notable cases are reformulated by the theory.</p>","PeriodicalId":20079,"journal":{"name":"Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics","volume":"62 6 Pt B","pages":"8842-5"},"PeriodicalIF":0.0,"publicationDate":"2000-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1103/physreve.62.8842","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21960149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analytic calculation of the anomalous exponents in turbulence: using the fusion rules to flush out a small parameter","authors":"L'vov,&nbsp;Procaccia","doi":"10.1103/physreve.62.8037","DOIUrl":"https://doi.org/10.1103/physreve.62.8037","url":null,"abstract":"<p><p>The main difficulty of statistical theories of fluid turbulence is the lack of an obvious small parameter. In this paper we show that the formerly established fusion rules can be employed to develop a theory in which Kolmogorov's statistics of 1941 (K41) acts as the zero order, or background statistics, and the anomalous corrections to the K41 scaling exponents zeta(n) of the nth-order structure functions can be computed analytically. The crux of the method consists of renormalizing a four-point interaction amplitude on the basis of the fusion rules. This amplitude includes a small dimensionless parameter, which is shown to be of the order of the anomaly of zeta(2), delta(2)=zeta(2)-2/3 approximately 0.03. Higher-order interaction amplitudes are shown to be even smaller. The corrections to K41 to O(delta(2)) result from standard logarithmically divergent ladder diagrams in which the four-point interaction acts as a \"rung.\" The theory allows a calculation of the anomalous exponents zeta(n) in powers of the small parameter delta(2). The n dependence of the scaling exponents zeta(n) stems from pure combinatorics of the ladder diagrams. In this paper we calculate the exponents zeta(n) up to O(delta32). Previously derived bridge relations allow a calculation of the anomalous exponents of correlations of the dissipation field and of dynamical correlations in terms of the same parameter delta(2). The actual evaluation of the small parameter delta(2) from first principles requires additional developments that are outside the scope of this paper.</p>","PeriodicalId":20079,"journal":{"name":"Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics","volume":"62 6 Pt A","pages":"8037-57"},"PeriodicalIF":0.0,"publicationDate":"2000-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1103/physreve.62.8037","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21960241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Self-focusing of a single laser pulse in a photorefractive medium","authors":"Wolfersberger,&nbsp;Fressengeas,&nbsp;Maufoy,&nbsp;Kugel","doi":"10.1103/physreve.62.8700","DOIUrl":"https://doi.org/10.1103/physreve.62.8700","url":null,"abstract":"<p><p>An original experimental and theoretical time-resolved study of a single laser pulse self-focusing in a nonlinear photorefractive medium is reported. The behavior of the self-focusing process is experimentally observed in a photorefractive Bi12TiO20 crystal during the 5 ns pulse duration of a doubled Nd:YAG (yttrium aluminum garnet) laser. A theoretical interpretation is provided, based on a simple model of photorefraction on the nanosecond time scale.</p>","PeriodicalId":20079,"journal":{"name":"Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics","volume":"62 6 Pt B","pages":"8700-4"},"PeriodicalIF":0.0,"publicationDate":"2000-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1103/physreve.62.8700","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21960256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cavity solitons in semiconductor microresonators: existence, stability, and dynamical properties","authors":"Maggipinto,&nbsp;Brambilla,&nbsp;Harkness,&nbsp;Firth","doi":"10.1103/physreve.62.8726","DOIUrl":"https://doi.org/10.1103/physreve.62.8726","url":null,"abstract":"<p><p>We apply a versatile numerical technique to establishing the existence of cavity solitons (CS) in a semiconductor microresonator with bulk GaAs or multiple quantum well GaAs/AlGaAs as its active layer. Based on a Newton method, our approach implies the evaluation of the linearized operator describing deviations from the exact stationary state. The eigenvalues of this operator determine the dynamical stability of the CS. A typical eigenspectrum contains a zero eigenvalue with which a \"neutral mode\" of the CS is associated. Such neutral modes are characteristic of models with translational symmetry. All other eigenvalues typically have negative real parts large enough to cause any excitations to die out in a few medium response times. The neutral mode thus dominates the response to external random or deterministic perturbations, and its excitation induces a simple translation of the CS, which are thus stable and robust. We show how to relate the speed with which a CS moves under external perturbations to the projection of the perturbations on to the neutral mode, and give some examples, including weak gradients on the driving field and interaction with other CS. Finally, we show that the separatrix between two stable coexisting solutions: the homogeneous solution and the CS is the intervening unstable CS solution. Our results are important with a view to future applications of CS to optical information processing.</p>","PeriodicalId":20079,"journal":{"name":"Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics","volume":"62 6 Pt B","pages":"8726-39"},"PeriodicalIF":0.0,"publicationDate":"2000-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1103/physreve.62.8726","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21960260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Anomalous diffusion of particles driven by correlated noise","authors":"Denisov,&nbsp;Horsthemke","doi":"10.1103/physreve.62.7729","DOIUrl":"https://doi.org/10.1103/physreve.62.7729","url":null,"abstract":"<p><p>We study the effect of an arbitrary stationary random force on the motion of damped particles. Using a Langevin description, we derive exact expressions for the dispersion of the particle position, of the particle velocity, and their cross dispersion. The particles can exhibit anomalous diffusion, and the connection between this behavior and the functional form of the noise correlations is investigated in detail. We also study anomalous diffusion for the special cases of overdamped and undamped particles.</p>","PeriodicalId":20079,"journal":{"name":"Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics","volume":"62 6 Pt A","pages":"7729-34"},"PeriodicalIF":0.0,"publicationDate":"2000-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1103/physreve.62.7729","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21960671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Convective rolls and heat transfer in finite-length rayleigh-Benard convection: A two-dimensional numerical study","authors":"Kenjeres,&nbsp;Hanjalic","doi":"10.1103/physreve.62.7987","DOIUrl":"https://doi.org/10.1103/physreve.62.7987","url":null,"abstract":"<p><p>A two-dimensional (2D) numerical study using a single-point algebraic k-straight theta;(2)-varepsilon-varepsilon(straight theta) turbulence closure was performed to detect the existence, origin, creation and behavior of convective rolls and associated wall Nusselt (Nu) number variation in thermal convection in 2D horizontal slender enclosures heated from below. The study covered the Rayleigh (Ra) numbers from 10(5) to 10(12) and aspect ratios from 4:1 to 32:1. The time evolution of the convective rolls and the formation of the corner vortices were analyzed using numerical flow visualization, and the correlation between roll structures and heat transfer established. A major consequence of the imposed two dimensionality appeared in the persistence of regular roll structures at higher Ra numbers that approach a steady state for all configurations considered. This finding contradicts the full three-dimensional direct numerical simulations (DNS), large eddy simulations (LES), and three-dimensional transient Reynolds-averaged Navier-Stokes (TRANS) computations, which all show continuously changing unsteady patterns. However, the final-stage roll structures, long-term averaged mean temperature and turbulence moments, and the Nusselt number (both local and integral), are all reproduced in good agreement with the ensemble-averaged 3D DNS, TRANS, and several recent experimental results. These findings justified the 2D approach as an acceptable method for ensemble average analysis of fully 3D flows with at least one homogeneous direction. Based on our 2D computations and adopting the low and high Ra number asymptotic power laws of Grossmann and Lohse [J. Fluid Mech. 407, 27 (2000)], new prefactors in the Nu-Ra correlation for Pr=O(1) were proposed that fit better several sets of data over a wide range of Ra numbers and aspect ratios: Nu=0.1Ra(1/4)+0.05Ra(1/3). Even better agreement of our computations was achieved with the new correlation Nu=0.124 Ra0.309 proposed recently by Niemela et al. [Nature (London) 404, 837 (2000)] for 10(6)</=Ra</=10(17).</p>","PeriodicalId":20079,"journal":{"name":"Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics","volume":"62 6 Pt A","pages":"7987-98"},"PeriodicalIF":0.0,"publicationDate":"2000-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1103/physreve.62.7987","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21961030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Velocity space scattering coefficients with applications in antihydrogen recombination studies","authors":"Chang,&nbsp;Ordonez","doi":"10.1103/physreve.62.8564","DOIUrl":"https://doi.org/10.1103/physreve.62.8564","url":null,"abstract":"<p><p>An approach for calculating velocity space friction and diffusion coefficients with Maxwellian field particles is developed based on a kernel function derived in a previous paper [Y. Chang and C. A. Ordonez, Phys. Plasmas 6, 2947 (1999)]. The original fivefold integral expressions for the coefficients are reduced to onefold integrals, which can be used for any value of the Coulomb logarithm. The onefold integrals can be further reduced to standard analytical expressions by using a weak coupling approximation. The integral expression for the friction coefficient is used to predict a time scale that describes the rate at which a reflecting antiproton beam slows down within a positron plasma, while both species are simultaneously confined by a nested Penning trap. The time scale is used to consider the possibility of achieving antihydrogen recombination within the trap. The friction and diffusion coefficients are then used to derive an expression for calculating the energy transfer rate between antiprotons and positrons. The expression is employed to illustrate achieving antihydrogen recombination while taking into account positron heating by the antiprotons. The effect of the presence of an electric field on recombination is discussed.</p>","PeriodicalId":20079,"journal":{"name":"Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics","volume":"62 6 Pt B","pages":"8564-72"},"PeriodicalIF":0.0,"publicationDate":"2000-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1103/physreve.62.8564","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21961035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Glassy dynamics near zero temperature","authors":"Ricci-Tersenghi,&nbsp;Zecchina","doi":"10.1103/physreve.62.r7567","DOIUrl":"https://doi.org/10.1103/physreve.62.r7567","url":null,"abstract":"<p><p>We numerically study finite-dimensional spin glasses at low and zero temperature, finding evidence for (i) strong time-space heterogeneities, (ii) spontaneous time scale separation, and (iii) power law distributions of flipping times. Using zero temperature dynamics we study blocking, clustering and persistence phenomena.</p>","PeriodicalId":20079,"journal":{"name":"Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics","volume":"62 6 Pt A","pages":"R7567-70"},"PeriodicalIF":0.0,"publicationDate":"2000-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1103/physreve.62.r7567","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21959000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Muonic helium atom as a classical three-body problem","authors":"Stuchi,&nbsp;Antunes,&nbsp;Andreu","doi":"10.1103/physreve.62.7831","DOIUrl":"https://doi.org/10.1103/physreve.62.7831","url":null,"abstract":"<p><p>We study the classical problem of the muonic helium atom, a helium atom with one of its electrons replaced by a muon. First, we establish the connection of the model with the one-dimensional frozen planetary approximation of the helium atom and find that there is classically stable motion for the configuration alpha-particle-electron-muon, and no stable motion for the alpha-particle-muon-electron configuration. After that, we introduce the restricted muonic helium problem, a model for the movement of an electron in the potential of the alpha particle/muon pair moving in a circular orbit. In this model, the equilibrium points, their associated Lyapunov families of periodic orbits, and their stability parameters were studied. The most interesting feature is the stability of the halo orbits, for a range of energy values. The vicinity of the alpha particle is also studied, examining Poincare sections for increasing energy values showing an increase of the chaotic motion.</p>","PeriodicalId":20079,"journal":{"name":"Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics","volume":"62 6 Pt A","pages":"7831-41"},"PeriodicalIF":0.0,"publicationDate":"2000-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1103/physreve.62.7831","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21959291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}