Gravitational collapse with charge and small asymmetries

Paper I analyzed the evolution of nonspherical scalar-field perturbations of an electrically charged, collapsing star; this paper treats coupled electromagnetic and gravitational perturbations. It employs the results of recent detailed work in which coupled perturbations were studied in a gauge-invariant manner by using the Hamiltonian (Moncrief's) approach and the Newman-Penrose formalism, and the relations between the fundamental quantities of these two methods were obtained. It is shown that scalar-field perturbations are a prototype for coupled perturbations. the collapse produces a Reissner-Nordstrom black hole, and the perturbations are radiated away completely. All l-pole parts of the perturbations of the metric and the electromagnetic field decay according to power laws;in the extreme case (e2=M2), the interaction causes the quadrupole perturbations to die out more slowly than the dipole perturbations. (author)