HAWKING RADIATION AND MASSES IN GENERALIZED DILATON THEORIES

A generalized dilaton action is considered of which the standard dilat on black hole and spherically reduced gravity are particular cases. Th e Arnowitt-Deser-Misner (ADM) and the Bondi-Sachs (BS) mass are calcul ated. Special attention is paid to both the asymptotic conditions for the metric as well as for the reference spacetime. For the latter one we suggest a modified expression thereby obtaining a new definition of energy. Depending on the parameters of the model the Hawking radiatio n behaves like a positive or negative power of the mass.