GLOBAL CHARGES IN CHERN-SIMONS THEORY AND THE 2-BLACK-HOLE(1)

We use the Regge-Teitelboim method to treat surface integrals in gauge theories to find global charges in Chern-Simons theory. We derive the affine and Virasoro generators as global charges associated with symm etries of the boundary. The role of boundary conditions is clarified. We prove that for diffeomorphisms that do not preserve the boundary th ere is a classical contribution to the central charge in the Virasoro algebra. The example of anti-de Sitter 2+1 gravity is considered in de tail.