ON THE RELATION BETWEEN THE GENERALIZED PAULI-VILLARS AND THE COVARIANT REGULARIZATION

Some aspects of the comparison that has been established recently by F ujikawa between the generalized Pauli-Villars regularization and the c ovariant regularization of composite current operators are investigate d, in particular, the fundamental question of the choice of regulator, satisfying appropriate conditions. The notion of zeta function of the operators is basic in the discussion. While developing the method, so me new formulas that are very useful in physical applications of the t heory are given.