Constrained field theories on spherically symmetric spacetimes with   horizons
  We apply the Dirac-Bergmann algorithm for the analysis of constraints to gauge theories defined on spherically symmetric black hole backgrounds. We find that the constraints for a given theory are modified on such spacetimes through the presence of additional contributions from the horizon. As a concrete example, we consider the Maxwell field on a black hole background, and determine the role of the horizon contributions on the dynamics of the theory. 
Karan Fernandes, Suman Ghosh, Amitabha Lahiri
gr-qc