Anderson-Mott transition in a magnetic field: Corrections to scaling

It is shown that the Anderson-Mott metal-insulator transition of paramagnet ic interacting disordered electrons in an external magnetic field is in the same universality class as the transition from a ferromagnetic metal to a ferromagnetic insulator discussed recently. As a consequence, large correct ions to scaling exist in the magnetic-field universality class, which have been neglected in previous theoretical descriptions. The nature and consequ ences of these corrections to scaling are discussed.