  We present the first rigorous example of the Hubbard model in any dimensions
which exhibits metallic ferromagnetism. The model is a genuine Hubbard model
with short-range hopping and on-site Coulomb repulsion, and has multi
single-electron bands. In the limit where the band gap and the Coulomb
repulsion become infinite, we prove that the ground states are completely
ferromagnetic and at the same time conducting.
