arXiv: Chaotic Dynamics最新文献_第4页

Multiple-parameter bifurcation analysis in a Kuramoto Model with Time Delay and Distributed Shear 具有时滞和分布剪切的Kuramoto模型的多参数分岔分析

arXiv: Chaotic Dynamics Pub Date : 2016-08-11 DOI: 10.1063/1.5029512

Ben Niu, Jiaming Zhang, Junjie Wei

引用次数: 3

Constrained n-Body Problems 约束n体问题

arXiv: Chaotic Dynamics Pub Date : 2016-06-10 DOI: 10.1007/978-3-319-08266-0_22

Wojciech Szumi'nski, M. Przybylska

引用次数: 0

Analysis of a Constrained Two-Body Problem 一类约束二体问题的分析

arXiv: Chaotic Dynamics Pub Date : 2016-06-09 DOI: 10.1007/978-3-319-42408-8_29

Wojciech Szumi'nski, Tomasz Stachowiak

引用次数: 0

Low-frequency regime transitions and predictability of regimes in a barotropic model 正压模式中的低频状态转换和状态的可预测性

arXiv: Chaotic Dynamics Pub Date : 2016-05-19 DOI: 10.1017/9781316339251.006

B. Nadiga, T. O’Kane

{"title":"Low-frequency regime transitions and predictability of regimes in a barotropic model","authors":"B. Nadiga, T. O’Kane","doi":"10.1017/9781316339251.006","DOIUrl":"https://doi.org/10.1017/9781316339251.006","url":null,"abstract":"Predictability of flow is examined in a barotropic vorticity model that admits low frequency regime transitions between zonal and dipolar states. Such transitions in the model were first studied by Bouchet and Simonnet (2009) and are reminiscent of regime change phenomena in the weather and climate systems wherein extreme and abrupt qualitative changes occur, seemingly randomly, after long periods of apparent stability. Mechanisms underlying regime transitions in the model are not well understood yet. From the point of view of atmospheric and oceanic dynamics, a novel aspect of the model is the lack of any source of background gradient of potential-vorticity such as topography or planetary gradient of rotation rate (e.g., as in Charney & DeVore '79). \u0000We consider perturbations that are embedded onto the system's chaotic attractor under the full nonlinear dynamics as bred vectors---nonlinear generalizations of the leading (backward) Lyapunov vector. We find that ensemble predictions that use bred vector perturbations are more robust in terms of error-spread relationship than those that use Lyapunov vector perturbations. In particular, when bred vector perturbations are used in conjunction with a simple data assimilation scheme (nudging to truth), we find that at least some of the evolved perturbations align to identify low-dimensional subspaces associated with regions of large forecast error in the control (unperturbed, data-assimilating) run; this happens less often in ensemble predictions that use Lyapunov vector perturbations. Nevertheless, in the inertial regime we consider, we find that (a) the system is more predictable when it is in the zonal regime, and that (b) the horizon of predictability is far too short compared to characteristic time scales associated with processes that lead to regime transitions, thus precluding the possibility of predicting such transitions.","PeriodicalId":166772,"journal":{"name":"arXiv: Chaotic Dynamics","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133598679","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}

引用次数: 4

Weak transient chaos 弱瞬态混沌

arXiv: Chaotic Dynamics Pub Date : 2016-05-18 DOI: 10.1007/978-3-319-53673-6_1

V. Afraimovich, A. Neiman

引用次数: 1

Chaos and Stochastic Models in Physics: Ontic and Epistemic Aspects 物理学中的混沌和随机模型:本体和认知方面

arXiv: Chaotic Dynamics Pub Date : 2016-05-09 DOI: 10.1007/978-3-319-28163-6_8

S. Caprara, A. Vulpiani

引用次数: 1

Full particle orbit effects in regular and stochastic magnetic fields 规则和随机磁场中的全粒子轨道效应

arXiv: Chaotic Dynamics Pub Date : 2016-04-18 DOI: 10.1063/1.4958653

Shun Ogawa, Benjamin Cambon, X. Leoncini, M. Vittot, D. D. Castillo-Negrete, G. Dif-Pradalier, X. Garbet

{"title":"Full particle orbit effects in regular and stochastic magnetic fields","authors":"Shun Ogawa, Benjamin Cambon, X. Leoncini, M. Vittot, D. D. Castillo-Negrete, G. Dif-Pradalier, X. Garbet","doi":"10.1063/1.4958653","DOIUrl":"https://doi.org/10.1063/1.4958653","url":null,"abstract":"We present a numerical study of charged particle motion in a time-independent magnetic field in cylindrical geometry. The magnetic field model consists of an unperturbed reversed-shear helical part and a perturbation consisting of a superposition of modes. Contrary to most of the previous studies, the particle trajectories are computed by directly solving the full Lorentz force equations of motion in a six-dimensional phase space using a sixth-order, implicit, symplectic Gauss-Legendre method. The level of stochasticity in the particle orbits is diagnosed using averaged, effective Poincare sections. It is shown that when only one mode is present the particle orbits can be stochastic even though the magnetic field line orbits are not stochastic. The lack of integrability of the particle orbits in this case is related to separatrix crossing and the breakdown of the global conservation of the magnetic moment. Some perturbation consisting of two modes creates resonance overlapping, leading to Hamiltonian chaos in magnetic field lines. Then, the particle orbits exhibit a nontrivial dynamics depending on their energy and pitch angle. It is shown that the regions where the particle motion is stochastic decrease as the energy increases. The non-monotonicity of the $q$-profile implies the existence of magnetic ITBs which correspond to shearless flux surfaces located in the vicinity of the $q$-profile minimum. It is shown that depending on the energy, these magnetic ITBs might or might not confine particles. That is, magnetic ITBs act as an energy-dependent particle confinement filter. Magnetic field lines in reversed-shear configurations exhibit topological bifurcations due to separatrix reconnection. We show that a similar but more complex scenario appears in the case of particle orbits that depends in a non-trivial way on the energy and pitch angle of the particles.","PeriodicalId":166772,"journal":{"name":"arXiv: Chaotic Dynamics","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124993379","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}

引用次数: 9

Existence of Unpredictable Solutions and Chaos 不可预测解的存在性与混沌

arXiv: Chaotic Dynamics Pub Date : 2016-02-08 DOI: 10.3906/MAT-1603-51

M. Akhmet, M. O. Fen

引用次数: 30

Self-induced switchings between multiple space-time patterns on complex networks of excitable units 可激元复杂网络中多重时空模式的自诱导切换

arXiv: Chaotic Dynamics Pub Date : 2016-02-05 DOI: 10.1103/PhysRevX.6.011030

Gerrit Ansmann, K. Lehnertz, U. Feudel

{"title":"Self-induced switchings between multiple space-time patterns on complex networks of excitable units","authors":"Gerrit Ansmann, K. Lehnertz, U. Feudel","doi":"10.1103/PhysRevX.6.011030","DOIUrl":"https://doi.org/10.1103/PhysRevX.6.011030","url":null,"abstract":"We report on self-induced switchings between multiple distinct space--time patterns in the dynamics of a spatially extended excitable system. These switchings between low-amplitude oscillations, nonlinear waves, and extreme events strongly resemble a random process, although the system is deterministic. We show that a chaotic saddle -- which contains all the patterns as well as channel-like structures that mediate the transitions between them -- is the backbone of such a pattern switching dynamics. Our analyses indicate that essential ingredients for the observed phenomena are that the system behaves like an inhomogeneous oscillatory medium that is capable of self-generating spatially localized excitations and that is dominated by short-range connections but also features long-range connections. With our findings, we present an alternative to the well-known ways to obtain self-induced pattern switching, namely noise-induced attractor hopping, heteroclinic orbits, and adaptation to an external signal. This alternative way can be expected to improve our understanding of pattern switchings in spatially extended natural dynamical systems like the brain and the heart.","PeriodicalId":166772,"journal":{"name":"arXiv: Chaotic Dynamics","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115344240","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}

引用次数: 41

Correlation decay and large deviations for mixed systems 混合系统的相关衰减和大偏差

arXiv: Chaotic Dynamics Pub Date : 2016-01-12 DOI: 10.1142/9789813202740_0004

R. Artuso, C. Manchein, Matteo Sala

引用次数: 1