Gregor Leiler

The Boltzmann collision equation in quantum field theory


The Boltzmann collision equation is a frequently used tool in physics. Its application ranges from the analysis of classical gases to quantitative predictions of early universe scenarios, like nucleosynthesis and baryogenesis. Unfortunately, the theoretical status of this equation within quantum field theory is not so clear. We present a formal derivation and remark upon the crucial approximations and how one can, in principle, obtain more accurate equations. We also briefly mention to what extent our considerations are relevant to physical questions in the early universe.