Microscopic structure of an interacting boson model in terms of the Dyson boson mapping

In an application of the generalized Dyson boson mapping to a shell model Hamiltonian acting in a single $j$ shell, a clear distinction emerges between pair bosons and kinematically determined seniority bosons. As in the Otsuka-Arima-Iachello method it is found that the latter type of boson determines the structure of an interactive boson-model-like Hamiltonian for the single $j$-shell model. It is furthermore shown that the Dyson boson mapping formalism is equally well suited for investigating possible interactive boson-model-like structures in a multishell case, where dynamical considerations are expected to play a much more important role in determining the structure of physical bosons.NUCLEAR STRUCTURE Boson mapping, interacting boson model, shell model.