The appearance of infinitely-many period-doubling cascades is one of the most prominent features observed in the study of maps depending on a parameter. They are associated with chaotic behavior, since bifurcation diagrams of a map with a parameter often reveal a complicated intermingling of period-doubling cascades and chaos. Period doubling can be studied at three levels of complexity. The first is an individual period-doubling bifurcation. The second is an infinite collection of period doublings that are connected together by periodic orbits in a pattern called a cascade. It was first described by Myrberg and later in more detail by Feigenbaum. The third involves infinitely many cascades and a parameter value $μ_2$ of the map at which there is chaos. We show that often virtually all (i.e., all but finitely many) ``regular'' periodic orbits at $μ_2$ are each connected to exactly one cascade by a path of regular periodic orbits; and virtually all cascades are either paired -- connected to exactly one other cascade, or solitary -- connected to exactly one regular periodic orbit at $μ_2$. The solitary cascades are robust to large perturbations. Hence the investigation of infinitely many cascades is essentially reduced to studying the regular periodic orbits of $F(μ_2, \cdot)$. Examples discussed include the forced-damped pendulum and the double-well Duffing equation.
Spatiotemporal chaos in the form of defect-mediated turbulence is known for oscillators coupled by diffusion. Here we explore the same conditions that produce defect turbulence, in an array of oscillators that are coupled through the activator to a regular oscillator. We find that for very small coupling the oscillators behave independent of each other and then there is a transition to complete synchronization. On further increasing the coupling strength, there is period doubling and a transition to chaotic behavior of each driven unit. However the global behavior shows some ordering, and the …
In the present study, we investigate the dynamics of impulsive differential equations driven by a chaotic system. We rigorously prove that, likewise the drive, the response impulsive system is also chaotic. Our results are based on the presence of sensitivity and infinitely many unstable periodic motions. The theoretical results are supported by simulations.
In this study, replication of a period-doubling cascade in coupled systems with delay is rigorously proved under certain assumptions, which guarantee the existence of bounded solutions and replication of sensitivity. A novel definition for replication of sensitivity is utilized, in which the proximity of solutions is considered in an interval instead of a single point. Examples with simulations supporting the theoretical results concerning sensitivity and period-doubling cascade are provided.
We visit a previously proposed discontinuous, two-parameter generalization of the continuous, one-parameter logistic map and present exhaustive numerical studies of the behavior for different values of the two parameters and initial points. In particular, routes to chaos exist that do not exhibit period-doubling whereas period-doubling is the sole route to chaos in the logistic map. Aperiodic maps are found that lead to cobwebs with x = infinity as accumulation points, where every neighborhood contains infinitely many points generated by the map.
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。
Interruption of torus doubling bifurcation and genesis of strange nonchaotic attractors in a quasiperiodically forced map : Mechanisms and their characterizations
Highly symmetric networks can exhibit partly symmetry-broken states, including clusters and chimera states, i.e., states of coexisting synchronized and unsynchronized elements. We address the $\mathbb{S}_4$ permutation symmetry of four globally coupled Stuart-Landau oscillators and uncover an interconnected web of differently symmetric solutions. Among these are chaotic $2\!-\!1\!-\!1$ minimal chimeras that arise from $2\!-\!1\!-\!1$ periodic solutions in a period-doubling cascade, as well as fully asymmetric chaotic states arising similarly from periodic $1\!-\!1\!-\!1\!-\!1$ solutions. A bac…
We add quantum fluctuations to a classical period-doubling Hamiltonian time crystal, replacing the $N$ classical interacting angular momenta with quantum spins of size $l$. The full permutation symmetry of the Hamiltonian allows a mapping to a bosonic model and the application of exact diagonalization for quite large system size. In the thermodynamic limit $N\to\infty$ the model is described by a system of Gross-Pitaevskii equations whose classical-chaos properties closely mirror the finite-$N$ quantum chaos. For $N\to\infty$, and $l$ finite, Rabi oscillations mark the absence of persistent pe…
We study a damped kicked top dynamics of a large number of qubits ($N \rightarrow \infty$) and focus on an evolution of a reduced single-qubit subsystem. Each subsystem is subjected to the amplitude damping channel controlled by the damping constant $r\in [0,1]$, which plays the role of the single control parameter. In the parameter range for which the classical dynamics is chaotic, while varying $r$ we find the universal period-doubling behavior characteristic to one-dimensional maps: period-two dynamics starts at $r_1 \approx 0.3181$, while the next bifurcation occurs at $ r_2 \approx 0.5387…
Multiple Transitions to Chaos in a Damped Parametrically Forced Pendulum
通过改变$ω_0$（摆的固有频率）和$A$（外驱动力的幅值），研究了有阻尼参数强迫摆的最低稳定点（SP）的稳定性。随着$A$增加，SP将在其不稳定后重新稳定，再次不稳定，因此对于任何给定的$ω_0$ { \it ad infinite}。它的失稳（再稳定）发生通过交替超临界（亚临界）倍周期分岔（PDB的）和干草叉分岔，除了第一次失稳，在超临界或亚临界分岔发生取决于$ω_0$的值。对于每一种情况下的超临界失稳，无限序列的PDB的遵循，并导致混乱。因此，随着$A$的增加，出现了无限系列的倍周期到混沌的转变。还讨论了相变点处的临界行为。
We review the occurrence of the patterns of the onset of chaos in low-dimensional nonlinear dissipative systems in leading topics of condensed matter physics and complex systems of various disciplines. We consider the dynamics associated with the attractors at period-doubling accumulation points and at tangent bifurcations to describe features of glassy dynamics, critical fluctuations and localization transitions. We recall that trajectories pertaining to the routes to chaos form families of time series that are readily transformed into networks via the Horizontal Visibility algorithm, and thi…
Numerical bifurcation analysis, and in particular two-parameter continuation, is used in consort with numerical simulation to reveal complicated dynamics in the Mackey-Glass equation for moderate values of the delay close to the onset of chaos. In particular a cusp bifurcation of periodic orbits and resulting branches of folds of periodic orbits effectively partition the parameter space into regions where different behaviours are seen. The cusp bifurcation leads directly to bistability between periodic orbits, and subsequently to bistability between a periodic orbit and a chaotic attractor. Th…
Bifurcation and chaos in the double well Duffing-van der Pol oscillator: Numerical and analytical studies
研究了驱动双阱Duffing-van der Pol（DVP）振荡器在特定参数选择（$\mid α\mid =β$）下的行为.在系统参数（$f-ω$）域中存在不同的吸引子进行检查和固定阻尼的各种稳定状态的详细说明。报道了通过混沌振荡从准周期运动到周期运动的转变。介入混沌制度进一步显示，具有岛屿的锁相状态和周期窗口（包括倍周期区域），边界危机，所有三个类的混沌，和瞬态混沌。我们还观察到在从拟周期解到周期解的过渡过程中存在间歇突变型的局部-全局分支和蓝天突变型的全局分支。利用微扰周期解，对各种形式的不稳定性进行了研究，可以预测$(f-ω)$平面上的Neimark不稳定性，并最终得到混沌区域的近似预测准则.
Routing games are amongst the most studied classes of games. Their two most well-known properties are that learning dynamics converge to equilibria and that all equilibria are approximately optimal. In this work, we perform a stress test for these classic results by studying the ubiquitous dynamics, Multiplicative Weights Update, in different classes of congestion games, uncovering intricate non-equilibrium phenomena. As the system demand increases, the learning dynamics go through period-doubling bifurcations, leading to instabilities, chaos and large inefficiencies even in the simplest case …
