Control of transient chaos in tent maps near crisis. I. Fixed point targeting

Terminating transient chaos in spatially extended systems

In many real-life systems, transient chaotic dynamics plays a major role. For instance, the chaotic spiral or scroll wave dynamics of electrical excitation waves during life-threatening cardiac arrhythmias can terminate by itself. Epileptic seizures have recently been related to the collapse of transient chimera states. Controlling chaotic transients, either by maintaining the chaotic dynamics or by terminating it as quickly as possible, is often desired and sometimes even vital (as in the case of cardiac arrhythmias). We discuss in this study that the difference of the underlying structures in state space between a chaotic attractor (persistent chaos) and a chaotic saddle (transient chaos) may have significant implications for efficient control strategies in real life systems. In particular, we demonstrate that in the latter case, chaotic dynamics in spatially extended systems can be terminated via a relatively low number of (spatially and temporally) localized perturbations. We demonstrate as a proof of principle that control and targeting of high-dimensional systems exhibiting transient chaos can be achieved with exceptionally small interactions with the system. This insight may impact future control strategies in real-life systems like cardiac arrhythmias.

Control of transient chaos in tent maps near crisis. II. Periodic orbit targeting

Recent work on a symbolic approach to the calculation of probability distributions arising in the application of the Ott-Grebogi-Yorke strategy to transiently chaotic tent maps is extended to the case of control to a nontrivial periodic orbit. Closed forms are derived for the probability of control being achieved and the average number of iterations to control when it occurs. Both single-component and multiple-component targeting are considered, and illustrative examples of the results obtained are presented.