Black Hole Radiation (with and) without Weyl Anomaly

Abstract

In the semiclassical analysis of black hole radiation in matter-coupled dilaton gravity, a one-parameter ``$k$"-family of measures for the path integral quantization of the matter fields is considered. The Weyl anomaly is proportional to the parameter $k$, but the black hole radiation seen by minkowskian observers at future null infinity is $k$-independent.

13 pages, LaTex. [Typographical error in Eq.(36) was corrected. Comments on the relation between our 2D-gravity results and some known results on the chiral Schwinger model were added. Two references were added.]