Effective action and Hawking radiation for dilaton coupled scalars in two dimensions - art. no. 084021

The effective one-loop action for general dilaton theories with an arbitrar y dilaton-dependent measure and nonminimal coupling to scalar matter is com puted. As an application we determine the Hawking flux to infinity from bla ck holes in D dimensions. We resolve the recently resurrected problem of an apparent negative flux for nonminimally coupled scalars: For any D greater than or equal to 4 black hole the complete flux turns out to be precisely the one of minimal coupling. This result is obtained from a Christensen-Ful ling type argument involving the (non)conservation of energy-momentum. It i s compared with approaches using the effective action. [S0556-2821(99)01416 -2].