Abstract

Co-authors: James Lucietti (Edinburgh U), Keiju Murata (Keio U), Harvey S. Reall (Cambridge U)

Recently, a novel instability was found for a massless scalar field on an extreme Reissner-Nordstrom black hole. This instability is due to purely classical effect, and it makes a part of energy-momentum tensor of the scalar field discontinuous on the horizon at late time. We show that a similar instability occurs in also for a massive scalar field and for coupled linearized gravitational and electromagnetic perturbations. We also study numerically the nonlinear evolution of this instability for spherically symmetric perturbations of an extreme Reissner-Nordstrom (RN) black hole. We find that generically the endpoint of the instability is a non-extreme RN solution, while there exist fine-tuned initial perturbations for which the instability never decays. We discuss the physical mechanism and implications of this instability, and also argue the final fate of the system after nonlinear effects set in.