Properties of the OneParticle Green's Function for Nonuniform ManyFermion Systems
Abstract
In this paper we discuss some general properties of the oneparticle Green's function, for nonuniform manyfermion systems and the associated singleparticle interpretation of physical properties of such systems. We consider, in particular, the groundstate energy, the density of particles in the ground state, and the singleparticle excitation spectrum. The investigation is restricted to the case of a static external field and a system at zero temperature. Various general approximation methods are studied starting from one in which the selfenergy operator is replaced by an Hermitian and energyindependent operator.
 Publication:

Physical Review
 Pub Date:
 January 1963
 DOI:
 10.1103/PhysRev.129.897
 Bibcode:
 1963PhRv..129..897L