Mass Inflation in Dynamical Gravitational Collapse of a Charged Scalar Field

During the last ten years evidence has been mounting that generically the Cauchy horizon inside a charged or a spinning black hole becomes a null, weak singularity which is a precursor of a strong, spacelike singularity along the r  =  0 hypersurface. We present here the missing link in this picture: A complete calculation from a regular initial data to the formation of a black hole and its inner singularities. We follow the gravitational collapse of a self-gravitating charged massless scalar field and observe the formation of an apparent horizon, a null, weak, mass-inflation singularity along the Cauchy horizon, and a final, spacelike, central singularity.