We explain how specific dynamical properties give rise to the limit distribution of sums of deterministic variables at the transition to chaos via the period-doubling route. We study the sums of successive positions generated by an ensemble of initial conditions uniformly distributed in the entire phase space of a unimodal map as represented by the logistic map. We find that these sums acquire their salient, multiscale, features from the repellor preimage structure that dominates the dynamics toward the attractors along the period-doubling cascade. And we explain how these properties transmit from the sums to their distribution. Specifically, we show how the stationary distribution of sums of positions at the Feigebaum point is built up from those associated with the supercycle attractors forming a hierarchical structure with multifractal and discrete scale invariance properties.
Drastic facilitation of the onset of global chaos in a periodically driven Hamiltonian system due to an extremum in the dependence of eigenfrequency on energy
We study the stability of a family of spherical equilibrium models of self-gravitating systems, the so-called $γ-$models with Osipkov-Merritt velocity anisotropy, by means of $N-$body simulations. In particular, we analyze the effect of self-consistent $N-$body chaos on the onset of radial-orbit instability (ROI). We find that degree of chaoticity of the system associated to its largest Lyapunov exponent $Λ_{\rm max}$ has no appreciable relation with the stability of the model for fixed density profile and different values of radial velocity anisotropy. However, by studying the distribution of…
We derive a semi-analytic criterion for the presence of chaos in compact, eccentric multiplanet systems. Beyond a minimum semimajor-axis separation, below which the dynamics are chaotic at all eccentricities, we show that (i) the onset of chaos is determined by the overlap of two-body mean motion resonances (MMRs), like it is in two-planet systems; (ii) secular evolution causes the MMR widths to expand and contract adiabatically, so that the chaotic boundary is established where MMRs overlap at their greatest width. For closely spaced two-planet systems, a near-symmetry strongly suppresses thi…
Statistical models provide a powerful and useful class of approximations for calculating reaction rates by bypassing the need for detailed, and often difficult, dynamical considerations. Such approaches invariably invoke specific assumptions about the extent of intramolecular vibrational energy flow in the system. However, the nature of the transition to the statistical regime as a function of the molecular parameters is far from being completely understood. Here, we use tools from nonlinear dynamics to study the transition to statisticality in a model unimolecular reaction by explicitly visul…
We investigate the onset of chaos in a periodically kicked Dicke model (KDM), using the out-of-time-order correlator (OTOC) as a diagnostic tool, in both the oscillator and the spin subspaces. In the large spin limit, the classical Hamiltonian map is constructed, which allows us to investigate the corresponding phase space dynamics and to compute the Lyapunov exponent. We show that the growth rate of the OTOC for the canonically conjugate coordinates of the oscillator is able to capture the Lyapunov exponent in the chaotic regime. The onset of chaos is further investigated using the saturation…
Different routes to chaos via strange nonchaotic attractor in a quasiperiodically forced system
研究了一类拟周期受迫动力系统的奇异非混沌吸引子。几条路线，包括标准的奇怪的非混沌吸引子的外观发生，被证明是可实现的在同一模型中的两个参数（$f-ε$）域的系统。特别地，借助于双参数（$f-ε$）相图，证明了环面通过SNA从倍周期到混沌的转变，环面通过SNA从倍周期到混沌的破缺以及分形环面的倍周期分岔。更有趣的是，为了接近奇怪的非混沌吸引子，存在的几个新的分歧对应的环面鼓泡的新现象的环面进行了描述。特别指出了通向混沌的新途径：（1）双频准周期性$\to$环面加倍$\to$环面并合，然后环面逐步分形，（二）双频率准周期性$\to$环面加倍$\to$混沌$\to$ SNA $\to$混沌$\to$逆环面加倍$\to$环面$\to$环面开始后的环面气泡通过SNA打破混沌或随后通过SNA开始环面加倍路径进入混沌。通过计算系统的李雅普诺夫指数、缠绕数、功率谱测度和维数等特征量，证实了奇异非混沌吸引子的存在性.各种分叉背后的机制也进行了简要讨论。
