THE BREAKDOWN OF FERMI-LIQUID THEORY IN THE HUBBARD-MODEL .2.

An exact diagrammatic analysis of the electron self-energy in the Hubbard and related models is given within the local approximation. Contact is made with recent work for dimension d = infinity where the local approximation becomes exact. It is shown that the approximate method of paper I of the series may be fitted into the new framework and yields sensible results for the Anderson impurity model. This lends weight to the prediction of I that for paramagnetic solutions of the Hubbard model Fermi liquid behaviour breaks down in a whole region of the T = 0 phase diagram, not just for a half-filled band where the Mott transition occurs.