Networks of coupled oscillators: from phase to amplitude chimeras

TL;DR

This paper demonstrates that amplitude-mediated phase chimeras and amplitude chimeras can coexist in the same network of identical oscillators, with their occurrence controlled by coupling strength, revealing long-lived and quasiperiodic variants.

Contribution

It introduces the coexistence and controllability of two distinct chimera states in nonlocally coupled oscillators, with insights into their bifurcation mechanisms.

Findings

Amplitude chimeras are long-lived, not transient.

Both chimera types can be induced by tuning coupling strength.

Variants with quasiperiodic oscillations are observed.

Abstract

We show that amplitude-mediated phase chimeras and amplitude chimeras can occur in the same network of nonlocally coupled identical oscillators. These are two different partial synchronization patterns, where spatially coherent domains coexist with incoherent domains and coherence/incoherence refer to both amplitude and phase or only the amplitude of the oscillators, respectively. By changing the coupling strength the two types of chimera patterns can be induced. We find numerically that the amplitude chimeras are not short-living transients but can have a long lifetime. Also, we observe variants of the amplitude chimeras with quasiperiodic temporal oscillations. We provide a qualitative explanation of the observed phenomena in the light of symmetry breaking bifurcation scenarios. We believe that this study will shed light on the connection between two disparate chimera states having different symmetry-breaking properties.