Numerical experiments testing the Kerr Limit, Naked Singularities and Surface Gravity*

We present results from numerical relativity simulations of accretion onto a black hole puncture. The simulations are aimed at investigating the possibility of violating the Kerr limit of rotating black holes. In particular, we focus our attention on the evolution of apparent horizons and the corresponding measure of mass, angular momentum and surface gravity. We address the challenges associated with identifying naked singularities in numerical simulations.