Generalized Kadanoff–Baym Theory for Non–Equilibrium Many–Body Systems in External Fields. An Effective Multi–Band Approach

The Kadanoff‐Baym approach (two‐time nonequilibrium Green's functions approach) is extended to charged particle systems in external fields. It is shown that its combination with an effecive multi‐band picture This concept was first presented at the German Physical Society (DPG) Spring meeting, Regensburg, March 1998 [1]. yields a powerful theoretical and numerical method to describe correlated many‐body systems in nonequilibrium.