Dynamics of Coupled Oscillator Systems - Abstract

Olmi, Simona

Ageing of chimera states

We consider a network of identical Kuramoto oscillators with inertia, subject to global mean field coupling. Depending on the phase-shift value we observe a transition from synchronized state to cluster synchronization and finally to chimera states. In particular, chimera states are formed by a coherent part, i.e. a stable cluster of oscillators frequency synchronized, plus an incoherent part, i.e. a free cloud of oscillators with different average frequencies. Numerical simulations have shown that such chimera states are transient phenomena subjected to ageing evolution. During this evolutionary process we can observe many small clusters forming, exchanging oscillators, breaking up and reforming in addition to the stable cluster of oscillators that is still present. The formation of short-lived minor clusters induces instability in the main cluster that tends to absorb other oscillators until the chimera state collapses in a cluster synchronized state with few solitary asynchronous oscillators still present. This novel phenomenon of reconfiguration and ageing of chimera states strongly depends on system size and initial conditions.