 Hartree-Fock-Bogoliubov theory

A self-consistent quadratic approximation to an interacting many-particle system that retains both normal one-particle densities and anomalous pair averages. Normal contractions supply Hartree and Fock fields, while anomalous contractions supply the pair potential. A Bogoliubov transformation preserving the appropriate fermion anticommutators or boson commutators diagonalizes the resulting Hamiltonian; the densities must then be recomputed to satisfy self-consistency and the particle-number constraint.