It is a great challenge of nonequilibrium statistical mechanics to calculate
entropy production within a microscopic theory. In the framework of linear
irreversible thermodynamics, we combine the Mori-Zwanzig-Forster projection
operator technique with the first and second law of thermodynamics to obtain
microscopic expressions for the entropy production as well as for the transport
equations of the entropy density and its time correlation function. We further
present a microscopic derivation of a dissipation functional from which the
dissipative dynamics of an extended dynamical density functional theory can be
obtained in a formally elegant way.Comment: 10 page