Fourth-order perturbation theory for the half-filled Hubbard model in infinite dimensions F. Gebhard, E. Jeckelmann, S. Mahlert, S. Nishimoto and R. M. Noack Eur. Phys. J. B, 36 4 (2003) 491-509 Published online: 30 January 2004 DOI: 10.1140/epjb/e2004-00005-5