N-particle sector of quantum field theory as a quantum open system
arXiv:hep-th/9611155 · doi:10.1103/PhysRevD.56.6702
Abstract
We give an exposition of a technique, based on the Zwanzig projection formalism, to construct the evolution equation for the reduced density matrix corresponding to the n-particle sector of a field theory. We consider the case of a scalar field with a interaction as an example and construct the master equation at the lowest non-zero order in perturbation theory.
12 pages, Latex