Nonlinearity of local dynamics promotes multi-chimeras

TL;DR

This paper investigates how increasing nonlinearity in coupled Van der Pol oscillators leads to the emergence of multi-chimera states with multiple incoherent domains, highlighting the role of nonlinearity and time delay in pattern formation.

Contribution

It demonstrates that stronger nonlinearity induces multi-chimera states and explores how stability and phase velocity profiles are affected by nonlinearity and time delay.

Findings

Multi-chimera states emerge with increased nonlinearity.

Stability regimes and phase velocity profiles vary with nonlinearity.

Time delay influences chimera pattern formation.

Abstract

Chimera states are complex spatio-temporal patterns in which domains of synchronous and asynchronous dynamics coexist in coupled systems of oscillators. We examine how the character of the individual elements influences chimera states by studying networks of nonlocally coupled Van der Pol oscillators. Varying the bifurcation parameter of the Van der Pol system, we can interpolate between regular sinusoidal and strongly nonlinear relaxation oscillations, and demonstrate that more pronounced nonlinearity induces multi-chimera states with multiple incoherent domains. We show that the stability regimes for multi-chimera states and the mean phase velocity profiles of the oscillators change significantly as the nonlinearity becomes stronger. Furthermore, we reveal the influence of time delay on chimera patterns.