ABSTRACT
We explore a new view on wave propagation in time-varying plasmas, where resonant interactions of monochromatic waves with photons and quasi-particles is considered. A distribution of quasiparticles, is used to describe a short laser beam or a generic turbulent state. Resonant interactions occur when the phase velocity of the large scale wave (for instance, a wakefield) is equal to the group velocity of the short wavelength, or quasi-particles, associated with the turbulent spectrum. It is shown that quasi-particle Landau damping can take place, as well as quasi-particle beam instabilities, thus establishing a direct link between the short and the large wavelength perturbations of the medium. Quasi-particle trapping is also discussed.
