Theoretical Methods For Strongly Correlated Electrons

TitleTheoretical Methods For Strongly Correlated Electrons
Publication TypeBook Chapter
Year of Publication2004
AuthorsAllen S, Tremblay A-MS, Vilk YM
EditorSénéchal D, Tremblay A-MS, Bourbonnais C
ChapterConserving approximations vs. two-particle self-consistent approach
Pagination341–355
PublisherSpringer
Abstract

The conserving approximation scheme to many-body problems was developed by Kadanoff and Baym using the functional-derivative approach. Another approach for the Hubbard model also satisfies conservation laws, but in addition it satisfies the Pauli principle and a number of sum rules. A concise formal derivation of that approach, using functional derivatives, is given in this conference paper to highlight formal analogies and differences with conserving approximations.