Is the multiplicative anomaly dependent on the regularization ?

In a recent work, T.S. Evans has claimed that the multiplicative anomaly associated with the zeta-function regularization of functional determinants is regularization dependent. We show that, if one makes use of consistent definitions, this is not the case and clarify some points in Evans’ argument. PACS numbers: 05.30.-d,05.30.Jp,11.10.Wx,11.15.Ex Recently, T.S. Evans [1] has investigated the role of the multiplicative anomaly in quantum field theory. His conclusions may be summarized by saying that the multiplicative anomaly is regularization dependent and can have therefore no physical relevance. In our opinion, as far as the zeta-function regularization issue is concerned, the starting point of Evans’ considerations is not the more appropriate , since he assumes that the (Euclidean) one-loop partition function (generating functional) is (formally) given by