Regularity of interacting nonspherical Fermi surfaces: The full self-energy

Regularity of the deformation of the Fermi surface under short-range intera ctions is established to all orders in perturbation theory. The proofs are based on a new classification of all graphs that are not doubly overlapping . They turn out to be generalized RPA graphs. This fact provides a simple e xtension to all orders of the regularity theorem of the Fermi surface movem ent proven in [2]. Models in which S is not symmetric under the reflection p --> -p are included. (C) 1999 John Wiley & Sons, Inc.