Late-time asymptotics for the wave equation on extremal Reissner-Nordström backgrounds
Yannis Angelopoulos, Stefanos Aretakis, Dejan Gajic
TL;DR
This paper delivers rigorous, fully global late-time asymptotics for solutions to the wave equation on extremal Reissner-Nordström backgrounds, expressing leading coefficients directly in terms of initial data. It develops purely physical-space methods, including novel $r^p$-weighted energy hierarchies and a singular time inversion theory, to disentangle near-horizon and near-infinity contributions to tails. A new horizon charge $H_0^{(1)}[\psi]$ is introduced and linked to time-inverted data, enabling precise descriptions of horizon, null-infinity, and interior dynamics, with results that confirm and extend prior heuristic and numerical analyses. The framework also yields decay properties for scalar invariants and insights into interior behavior relevant to strong cosmic censorship.
Abstract
We derive the precise late-time asymptotics for solutions to the wave equation on extremal Reissner-Nordström black holes and explicitly express the leading-order coefficients in terms of the initial data. Our method is based on purely physical space techniques. We derive novel weighted energy hierarchies and develop a singular time inversion theory, which allow us to uncover the subtle contribution of both the near-horizon and near-infinity regions to the precise asymptotics. We introduce a new horizon charge and provide applications pertaining to the interior dynamics of extremal black holes. Our work confirms, and in some cases extends, the numerical and heuristic analysis of Lucietti-Murata-Reall-Tanahashi, Ori-Sela and Blaksley-Burko.
