On generalized Waldmann-Snider equations. I: \({\dot \pi}\)-subdynamics (Q1079742)

Three kinetic equations for describing a dilute gas of particles with internal levels have been derived, the first being the Waldmann-Snider equation (W-S), the second its extension for weakly inhomogeneous systems and the third the generalized W-S equation for systems with arbitrarily spaced internal levels. These equations are derived inside the framework of the theory of subdynamics of the Brussels Group permitting to distinguish between non-equilibrium highly off-diagonal and shortly off- diagonal density operators. The \({\dot \pi}\)-subdynamics is explicitly constructed. A discussion concerning the above aspects has been included as well.