Exact gravitational shock waves and Planckian scattering on branes - art. no. 024025

We obtain a solution describing a gravitational shock wave propagating alon g a Randall-Sundrum brane. The interest of such a solution is twofold: on t he one hand, it is the first exact solution for a localized source on a Ran dall-Sundrum three-brane; On the other hand, one can use it to study forwar d scattering at Planckian energies, including the effects of the continuum of Kaluza-Klein modes. We map out the different regimes for the scattering obtained by varying the center-of-mass energy and the impact parameter. We also discuss exact shock waves in ADD scenarios with, compact extra dimensi ons.