Dieter Lüst, Ludwig-Maximilians-Universität München
Large $N$ Graviton Scattering and Black Hole Production

In this talk I describe scattering processes of gravitons in quantum gravity, both form the field theory and also from the string theory point of view. We will define a particular kinematical regime, where the energies of the two incoming gravitons are Trans-Planckian, and where at the same time the number $N$ of gravitons in the final state is very large. As we will argue, these $2$ to $N$ scattering amplitudes support the the idea that a black hole is produced, which is a bound state of $N$ gravitons in a quantum critical state. We will also argue that this picture has to be refined at extremely large energies, where an interesting transition from field theory to string theory takes place.