Ambiguities in Pauli-Villars regularization
  We investigate regularization of scalar one-loop integrals in the Pauli- Villars subtraction scheme. The results depend on the number of sub- tractions, in particular the finite terms that survive after the diver- gences have been absorbed by renormalization. Therefore the process of Pauli-Villars regularization is ambiguous. We discuss how these am- biguities may be resolved by applying an asymptotically large number of subtractions, which results in a regularization that is automatically valid in any number of dimensions. 
Ronald H.P. Kleiss, Tim W. Janssen
hep-ph