Two-dimensional gravitational anomalies, Schwinger terms, and dispersion relations (Q5931233): Difference between revisions

This paper deals with the calculation of the two-dimensional gravitational anomalies, specifically the Einstein and the Weyl anomalies. Also the gravitational Schwinger terms are considered. The purpose of this work is to show that all these anomalous features are easily obtained by the method of dispersion relations. The method of dispersion relations is extended to the case of pure gravitation. The chiral fermion loops coupled to gravitation are considered. The following questions are considered: the general structure of the (pseudo-) tensor amplitude, the dispersion relations for the relevant formfactors of the amplitude and the calculations of their imaginary parts via the Gutkosky rule, the equivalence between the dispersive approach and the dimensional regularization procedure, the derivation of the linearized gravitational anomalies from the Ward identities.