2d quantum gravity and black hole formation

The quantum integral of generic 2d quantum gravity can be performed exactly . The equivalence of dilaton theories toad theories with torsion and the us e of a light cone gauge are crucial. Scalar matter can be treated perturbat ively. A generalization of the Polyakov action emerges. For scattering of s calars in a fiat background already in the tree approximation for the first time the intermediate formation of a black hole is observed in an ab initi o quantum gravity computation.