## Can Landau-fluid models describe nonlinear Landau damping

The question of whether the Landau-fluid'' description of wave-particle resonances (e.g., Hammett and Perkins, Phys. Rev. Lett. {bold 64}, 3019 (1990)) can describe nonlinear Landau damping is addressed. It is found that this model can provide an adequate description of the Compton scattering of electron drift waves, but fails in the case of ion-temperature-gradient-driven modes near the threshold. The general conclusion is that Landau-fluid models have difficulty describing the dynamics associated with the product of two or more deeply resonant propagators.