Mode coupling in rotating gravitational collapse: Gravitational and electromagnetic perturbations

We consider the late-time evolution of gravitational and electromagnetic perturbations in realistic rotating Kerr spacetimes. We give a detailed analysis of the mode-coupling phenomena in rotating gravitational collapse. A consequence of this phenomena is that the late-time tail is dominated by modes which, in general, may have an angular distribution different from the original one. In addition, we show that different types of fields have different decaying rates. This result turns over the traditional belief (which has been widely accepted during the last three decades) that the late-time tail of gravitational collapse is universal.