The Boltzmann-Langevin equation derived from the real-time path formalism (Q1191718)

We derive the Boltzmann-Langevin equation using Green's function techniques in the real time path formalism. We start from the Martin- Schwinger hierarchy and close it approximately at the two-body level. A careful discussion of the initial conditions for the free two-body Green's function provides the flexibility to recover the discarded correlations as fluctuations leading to the Langevin force. The derivation is generalized to the \(T\)-matrix approach which allows to prove that one can use the same effective interaction in the meanfield as well as in the collision term and Langevin force.