the bulk properties of nuclear matter and those of collective nuclear states can be established. The self-consistent RPA offers also enhanced predictive power: By starting from a more and more refined energy functional one wishes to make reliable extrapolations towards the unknown territories of the nuclear chart. Phenomenology enters this scheme in the form of the effective two-nucleon (NN) and three-nucleon (NNN) interaction. Contrary to the bare NN and NNN interactions, these are tailored for the use in mean-field type calculations such as HF and RPA. An ansatz is typically made for the effective NN(N) force and an appropriate fitting strategy has to follow.

Highly accurate parameterizations of the bare NN force are nowadays available [@WSS1995; @Mac2001; @SKT1994]. At the same time, attempts are made to derive the NN, NNN, and many-nucleon force starting from first principles, within chiral perturbation theory [@EnM2003; @EGM2005]. The possibility is currently being explored to combine mean-field theory with such realistic NN potentials. Two methods have been developed recently for “taming" the NN interaction and thus making it usable within models like HF and RPA: the $V_{\text{low-}k}$ low-momentum interaction is derived within renormalization group theory [@BKS2003] and the $V_{\text{UCOM}}$ correlated NN interaction is derived using 