Delayed-feedback chimera states: Forced multiclusters and stochastic resonance

TL;DR

This paper investigates how delayed feedback, external forcing, and noise influence complex synchronization patterns like chimera states in nonlinear oscillators, revealing control mechanisms and noise-induced phenomena.

Contribution

It demonstrates the control of chimera states via external forcing and introduces noise-induced chimera states akin to stochastic resonance in delayed feedback systems.

Findings

Chimera and solitary states emerge during transition to chaos.

External forcing can induce and control chimera states.

Noise can generate chimera states where they otherwise do not occur.

Abstract

A nonlinear oscillator model with negative time-delayed feedback is studied numeri- cally under external deterministic and stochastic forcing. It is found that in the unforced system complex partial synchronization patterns like chimera states as well as salt-and-pepper like soli- tary states arise on the route from regular dynamics to spatio-temporal chaos. The control of the dynamics by external periodic forcing is demonstrated by numerical simulations. It is shown that one-cluster and multi-cluster chimeras can be achieved by adjusting the external forcing frequency to appropriate resonance conditions. If a stochastic component is superimposed to the determin- istic external forcing, chimera states can be induced in a way similar to stochastic resonance, they appear, therefore, in regimes where they do not exist without noise.