From collective oscillation to chimera state in a nonlocally excitable system

TL;DR

This paper demonstrates that chimera states can emerge in nonlocally coupled excitable systems through collective oscillations, revealing two types of chimera states depending on coupling strength and expanding understanding of complex spatiotemporal patterns.

Contribution

It is the first to show chimera states arising from excitable systems with nonlocal coupling, linking collective oscillations to chimera formation.

Findings

Two types of chimera states identified: phase-chimera and excitability-chimera.

Chimera states depend on coupling strength, with different dynamics at weak and strong coupling.

Collective oscillation induced by nonlocal coupling underpins chimera emergence.

Abstract

Chimera states, which consist of coexisting domains of spatially coherent and incoherent dynamics, have been widely found in nonlocally coupled oscillatory systems. We demonstrate for the first time that chimera states can emerge from excitable systems under nonlocal coupling in which isolated units only allow for the equilibrium. We theoretically reveal that nonlocal coupling induced collective oscillation is behind the occurrence of the chimera states. We find two different types of chimera states, phase-chimera state and excitability-chimera states, depending on the coupling strength. At weak coupling strength where collective oscillation is localized around the unstable homogeneous equilibrium, the chimera states are similar to the ones in nonlocally coupled phase oscillators. For the chimera states at strong coupling strength, the dynamics of both coherent units and incoherent units shift back and forth between low amplitude oscillation induced by collective oscillation and high amplitude oscillation induced by excitability of local units.