The solar wind plasma becomes more and more collisionless as we move farther away from the Sun, so that the distribution functions of the different species deviate strongly from the local Maxwellian. The most important consequence is that the lowest order hydrodynamic equations are no longer applicable. Therefore it is necessary to treat the problem from a kinetic point of view (See Stellar Winds).

Another area of interest centers on the stability analysis of astrophysical plasmas to the development of kinetic instabilities and their observational consequences. For example, we investigate the Langmuir turbulence generated by electron beams during solar flares and its conversion to radiofrequencies. This emission serves as a tracer of the properties of solar plasma, and can provide important information for the understanding of the acceleration mechanism.