ι ≠ 0 coupling in superconductors and the use of field quantization methods in the many body problem

Abstract

Physics of a general Bardeen-Cooper-Schrieffer type of reduced Hamiltonian and the use and misuse of Green's function techniques are studied. A large but finite system of N particles is considered. Suspicions (R. Balian, et al., Phys. Rev. Letters, 8: 372(1961)) that the Green's function formulation as such is incomplete are allayed. (L.N.N.)