  Using the Hubbard Hamiltonian for transition metal-3d and oxygen-2p states
with perovskite geometry, we present a dynamical mean field theory which
becomes exactin the limit of large coordination numbers or equivalently large
spatial dimensions $D$. The theory is based on a new description of these
systems for large $D$ using a selective treatment of different hopping
processes which can not be generated by a unique scaling of the hopping
element. The model is solved using a perturbational approach and an extended
non-crossing approximation. We discuss the breakdown of the perturbation theory
near half filling, the origin of the various 3d and 2p bands, the doping
dependence of its spectral weight, and the evolution of quasi particles at the
Fermi-level upon doping, leading to interesting insight into the dynamical
character of the charge carriers near the metal insulator instability of
transition metal oxide systems, three dimensional perovskites and other
strongly correlated transition metal oxides.
