Abstract
The extended Wick’s theorem for fermion operators, which is used to compute matrix elements of an arbitrary operator between two different quasiparticle vacuums, is reformulated to deal with quasiparticle vacuums expanded in a finite single particle basis not closed under the canonical transformation relating them. A new expression for the overlap of those quasiparticle vacuums is also given.
- Received 31 May 1994
DOI:https://doi.org/10.1103/PhysRevC.50.2874
©1994 American Physical Society
