EXACT PATH-INTEGRAL QUANTIZATION OF GENERIC 2D DILATON GRAVITY

Local path integral quantization of generic 2D dilaton gravity is cons idered. Locality means that we assume asymptotic fall-off conditions f or all fields. We demonstrate that in the absence of ''matter'' fields to all orders of perturbation theory and for all 2D dilaton theories the quantum effective action coincides with the classical one. This re solves the apparent contradiction between the well-established results of Dirac quantization and perturbative (path-integral) approaches whi ch seemed to yield non-trivial quantum corrections. For a particular c ase, the Jackiw-Teitelboim model, our result is even extended to the s ituation when a matter field is present. (C) 1997 Elsevier Science B.V .