The complete quantum collapse scenario of a 2 + 1 dust shell: Preliminary calculations

If we consider the gravitational collapse of a material object to a black hole, we would expect, for ranges of mass where a black hole would form, the following scenario. A large enough object would collapse classically until an event horizon forms, and to an external observer the object would be lost from view. However, once the horizon has formed, the black hole will begin to emit Hawking radiation and the hole will lose mass and the horizon will shrink. The final state of this process could be either a zero-mass black hole with consequent information loss, or some sort of quantum remnant. A complete investigation of this process would require: 1) A complete and consistent theory of quantum gravity coupled to some kind of field that would provide the Hawking radiation [1] (which could be the gravitational field itself-gravitons); 2) Some kind of definition of a horizon in this quantum gravity, and; 3) The calculational tools to achieve a description of the scenario. Lacking these, one may resort to toy models to try to give some sort of a preliminary answer. In this paper we will consider the collapse of an infinitesimally thin dust shell in 2 + 1 gravity, where an exact minisuperspace quantum solution exists, and try to make rough estimates of the collapse-Hawking radiationremnant formation process.