Hawking Radiation ∗

It is shown in a variant of two dimensional dilaton gravity theories that an arbitrary , localized massive source put in an initially regular spacetime gives rise to formation of the wormhole classically, without accompanying the curvature singu-larity. The semiclassical quantum correction under this wormhole spacetime yields Hawking radiation. It is expected, with the quantum back reaction added to the classical equation, that the information loss paradox may be resolved in this model. The end point of the black hole evaporation poses a challenging conceptual problem that must be solved before one embarks on a full-fledged theory of quantum gravity. If the black hole is an inevitable consequence of the gravitational collapse, then one appears to have no alternative choice but to accept the thermal spectrum of Hawking radiation [1]. The question is then: does a quantum mechanical pure state develop into a mixed thermal state ? To answer this question in a definitive way, one presumably has to deal with the problem of quantum back reaction to the background spacetime, in this case, caused by Hawking radiation. Some interesting