Self-consistent RPA (SCRPA) theory is developed in the particle-partic
le (pp) channel. It is pointed out that in this way vertex and self-en
ergy corrections are taken into account on an equal footing whereas in
Bruckner-Hartree-Fock (BHF) this is not the case. We discuss in detai
l the interconnection between both theories and apply them to a model
case. Excellent agreement with the exact solution is found for SCRPA w
here as BHF gives somewhat poorer results. In an appendix it is demons
trated how SCRPA connects to a variational principle and how, for the
particle-hole case, sum rules and conservation laws are fulfilled. (C)
1998 Elsevier Science B.V.