  Using the general framework of quantum field theory, we derive basic
equations of quantum field kinetics. The main goal of this approach is to
compute the observables associated with a quark-gluon plasma at different
stages of its evolution. We start by rewriting the integral equations for the
field correlators in different forms, depending on the relevant dynamical
features at each different stage. Next, two versions of perturbation expansion
are considered. The first is best suited for the calculation of electromagnetic
emission from chaotic, but not equilibrated, strongly interacting matter. The
second version allows one to derive evolution equations, which are
generalizations of the familiar QCD evolution equations, and provide a basis
for the calculation of the initial quark and gluon distributions after the
first hard interaction of the heavy ions.
