Generalized Virasoro anomaly for dilaton coupled theories

Abstract

We derive the anomalous transformation law of the quantum stress tensor for a 2D massless scalar field coupled to an external dilaton. This provides a generalization of the Virasoro anomaly which turns out to be consistent with the trace anomaly. We apply these results to compute vacuum polarization of a spherical star based on the equivalence principle.

10 pages, latex; misprints corrected