N coupled oscillators synchronize when coupling K exceeds K_c = 2σ/π·g(0), where g is the frequency distribution.
Kuramoto (1975): dθᵢ/dt = ωᵢ + K/N Σⱼ sin(θⱼ−θᵢ). Order parameter r·e^iψ = (1/N)Σe^iθⱼ. Critical coupling K_c = 2/[π·g(0)] where g is the Lorentzian width σ. Above K_c, r jumps continuously (second-order transition).