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Kuramoto Oscillators and Synchronization

What you are seeing: 128 phase oscillators with intrinsic frequencies ωi\omega_i drawn from a Lorentzian distribution. Each oscillator advances at its own pace but is pulled by the global mean direction with strength KK: θ˙i=ωi+(K/N)jsin(θjθi)\dot{\theta}_i = \omega_i + (K/N) \sum_j \sin(\theta_j - \theta_i). The order parameter r=1Njeiθjr = |\frac{1}{N} \sum_j e^{i\theta_j}| measures how much the oscillators agree on a common direction.

Below the critical coupling Kc=2γK_c = 2 \gamma the oscillators are incoherent, scattered around the unit circle, and r0r \approx 0. Above KcK_c a fraction of oscillators lock onto a common phase ψ\psi and a coherent peak forms in the angular distribution; the laggard oscillators (those with extreme ωi\omega_i) still drift but a macroscopic order emerges, with rr rising as KKc\sqrt{K - K_c} above threshold.

Figure 1. Kuramoto synchronization. Method: forward Euler on the phase ODEs.
K1.50
gamma0.50
speed2

WHAT TO TRY

  • Raise the coupling K through the critical value K_c: the dots stop being scattered and bunch into a moving clump, the order-parameter arrow grows, and r(t) climbs off the floor toward 1.
  • Drop K below K_c and the clump disperses: the arrow collapses toward the centre and r(t) rattles near zero. This continuous onset of synchrony is the Kuramoto transition.
  • Widen the frequency spread gamma: it pushes K_c higher, so a coupling that synchronized a narrow population now leaves a broad one incoherent.