EXACT GROUND-STATE ENERGY OF THE PERIODIC ANDERSON MODEL IN D=1 AND EXTENDED EMERY MODELS IN D=1,2 FOR SPECIAL PARAMETER VALUES

We generalize an approach, which was recently introduced by Brandt and Giesekus to calculate the exact ground-state energy for strongly interacting particles on special perovskitelike lattices, to the periodic Anderson model in the dimension d=1 and to extended Emery models in d=1,2 on regular lattices for arbitrary spin degeneracy. For these models we calculate the exact ground-state energy for a restricted parameter regime in the strong-coupling limit. The ground-state energy shows a simple algebraic structure. We also present an eigenfunction of the Hamiltonian with the ground-state energy as its corresponding eigenvalue.