Initial correlated states for the generalized Kadanoff–Baym Ansatz without adiabatic switching-on of interactions in closed systemsMiroslav Hopjan and Claudio VerdozziEur. Phys. J. Special Topics, 227 15-16 (2019) 1939-1948DOI: https://doi.org/10.1140/epjst/e2018-800054-3