Solitary routes to chimera states

TL;DR

This paper investigates how solitary states in globally coupled FitzHugh-Nagumo oscillators can evolve into chimera states characterized by extensive chaos, through bifurcation analysis and chaos cascades.

Contribution

It introduces a novel mechanism linking solitary states to chaotic chimera states in large oscillator networks, supported by bifurcation and chaos analysis.

Findings

Solitary states can lead to chaotic chimera states.

Chaotic chimera states exhibit extensive chaos with multiple Lyapunov dimensions.

States with different numbers of incoherent oscillators coexist.

Abstract

We show how solitary states in a system of globally coupled FitzHugh-Nagumo oscillators can lead to the emergence of chimera states. By a numerical bifurcation analysis of a suitable reduced system in the thermodynamic limit we demonstrate how solitary states, after emerging from the synchronous state, become chaotic in a period-doubling cascade. Subsequently, states with a single chaotic oscillator give rise to states with an increasing number of incoherent chaotic oscillators. In large systems, these chimera states show extensive chaos. We demonstrate the coexistence of many of such chaotic attractors with different Lyapunov dimensions, due to different numbers of incoherent oscillators.