Photoemission bands in systems of strongly correlated electrons

Recent photoemission experiments on cuprate superconductors in their normal state are analyzed in the context of models of strongly correlated electrons. The phenomenon of antiferromagnetically induced bands close to half-filling is discussed. Also, flat regions in the dispersion of the valence band related to van Hove singularities in the electronic density of states are shown to be present. The possibility of having small, pocket-like Fermi surfaces in the vicinity of half-filling is mentioned. Finally, some analogies are presented between two-dimensional cuprates and related one-dimensional materials. (orig.)