The application of kinetic theory to compute transport coefficients in plasma often leads to divergent results. These infinities occur because in a plasma both close binary collisions and collective interactions play an essential role in the transport phenomena. In kinetic equation of Balescu - Guernsey - Lenard (BGL) and Botzmann either the former or the latter processes are neglected. Landau's equation is a hybrid of the two and has the deficiencies of both of them. In a more systematic approach the various interactions in the plasma are taken into account by starting from a kinetic equation with a composite collision term that is a unification of those of (BGL) and Boltzmann and the finiteness of the transport coefficient is guaranteed right from the start. Recently, instead of the one-particle distribution functions that constitute the central quantities of the older kinetic theories, attention has been focused on the time correlation functions from which transport coefficient follow by means of Green-Kubo relations. Dressing effects in plasma are included by "renormalizing" the interparticle potential that governs the evolution of the time correlation functions.

References