Nonquasilinear evolution of particle velocity in incoherent waves with   random amplitudes
  The one-dimensional motion of $N$ particles in the field of many incoherent waves is revisited numerically. When the wave complex amplitudes are independent, with a gaussian distribution, the quasilinear approximation is found to always overestimate transport and to become accurate in the limit of infinite resonance overlap. 
Yves Elskens (PIIM)