Relation of the interacting boson model to the shell model

A microscopic foundation of the interacting boson model is discussed from the shell model point of view. The Ginocchio model and the single j-shell model are taken to study various approximations for deriving the boson Hamiltonian. In the neutron-proton interacting boson model, we show the importance of the coupling to non-collective states for renormalizing some parameters in the boson Hamiltonian.