Mode-coupling in rotating gravitational collapse: Gravitational and electromagnetic perturbations

TL;DR

This paper analyzes how gravitational and electromagnetic perturbations decay over time in rotating Kerr spacetimes, revealing mode-coupling effects that challenge the traditional view of universal late-time tails.

Contribution

It provides a detailed analysis of mode-coupling phenomena in rotating gravitational collapse, showing that different fields decay at different rates and that late-time tails are not universal.

Findings

Late-time tails are dominated by modes with different angular distributions.

Different field types decay at different rates.

Mode-coupling significantly affects late-time evolution.

Abstract

We consider the late-time evolution of {\it gravitational} and electromagnetic perturbations in realistic {\it 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 {\it 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.