Chimera State — Partial Synchrony

In two coupled Kuramoto populations, one synchronizes while the other remains chaotically incoherent. Named for the mythical beast — half lion, half serpent. Discovered by Kuramoto & Battogtokh (2002).

Parameters

Order param. Pop 1 (r₁)
Order param. Pop 2 (r₂)
Chimera index
dθᵢ/dt = ωᵢ + (K/N)Σⱼ sin(θⱼ−θᵢ)

Chimera: one coherent cluster (r≈1) + one incoherent cluster (r≪1) coexist in a symmetric network — a paradox until 2002.