In-medium Relativistic Kinetic Theory and Nucleon-meson Systems Typeset Using Revt E X 2

Within the ?! model of coupled nucleon-meson systems, a generalized rel-ativistic Lennard{Balescu{equation is presented resulting from a relativistic random phase approximation (RRPA). This provides a systematic derivation of relativistic transport equations in the frame of nonequilibrium Green's function technique including medium eeects as well as uctuation eeects. It contains all possible processes due to one-meson exchange and special attention is kept to the oo{shell character of the particles. As a new feature of many-particle eeects, processes are possible, which can be interpreted as particle creation and annihilation due to in-medium one-meson exchange. In-medium cross sections are obtained from the generalized derivation of collision 1 integrals, which possess complete crossing symmetries.