Classical Black Hole Production in High-Energy Collisions
Douglas M. Eardley, Steven B. Giddings
TL;DR
The paper analyzes classical black hole formation in ultra-relativistic D-dimensional collisions by modeling each particle as a gravitational shock wave and reducing horizon formation to a boundary-value problem for Poisson's equation in the transverse space. It extends prior zero-impact-parameter results to nonzero impact parameter and provides an explicit $D=4$ trapped-surface construction via a conformal map, yielding a robust lower bound on the production cross-section and mass estimates for the resulting black hole. The results support the feasibility of black hole production at high energies and lay groundwork for a semiclassical treatment, while outlining the challenges and directions for higher-dimensional analysis and differential cross-section calculations. Overall, the work strengthens the theoretical foundations for predicting black hole production in TeV-scale gravity scenarios and informs experimental searches and cosmic-ray bounds.
Abstract
We investigate classical formation of a D-dimensional black hole in a high energy collision of two particles. The existence of an apparent horizon is related to the solution of an unusual boundary-value problem for Poisson's equation in flat space. For sufficiently small impact parameter, we construct solutions giving such apparent horizons in D=4. These supply improved estimates of the classical cross-section for black hole production, and of the mass of the resulting black holes. We also argue that a horizon can be found in a region of weak curvature, suggesting that these solutions are valid starting points for a semiclassical analysis of quantum black hole formation.
