The conformal trace anomalies for massless scalar, "neutrino," and photon fields propagating in an arbitrary Riemannian space-time are derived. They are seen to be a consequence of the subtraction, during renormalization, of a finite term, $\sim \ln \left(m^2{L}^2\right)$, which violates the scale invariance of the massless theory. A general derivation of the scalar anomaly is given based on the $\zeta$-function regularization developed earlier.

• Received 18 January 1977

DOI:https://doi.org/10.1103/PhysRevD.16.3390