Mott-Hubbard transition in infinite dimensions

We calculate the zero-temperature gap and quasiparticle weight of the half- filled Hubbard model with a random dispersion relation. After extrapolation to the thermodynamic limit, we obtain reliable bounds on these quantities for the Hubbard model in infinite dimensions. Our data indicate that the Mo tt-Hubbard transition is continuous; i.e., the quasiparticle weight becomes zero at the same critical interaction strength at which the gap opens.