Evolutions from extremality
Abstract
We examine the evolution of extremal spherically symmetric black holes, developing both general theory as well as the specific cases of (charged) null dust and massless scalar field spacetimes. As matter accretes onto extremal marginally trapped tubes, they generically evolve to become non-extremal with the initial extremal horizon bifurcating into inner and outer non-extremal horizons. At the start of this process arbitrarily slow matter accretion can cause a geometrically invariant measure of horizon growth to jump from zero to infinity. We also consider dynamical horizons that are extremal throughout their evolution and see that such spacetimes contain two extremal black hole horizons: an inner isolated one and an outer dynamical one. We compare these extremal dynamical horizons with the dynamical extreme event horizon spacetimes of Murata, Reall and Tanahashi.
Cite
@article{arxiv.1510.01759,
title = {Evolutions from extremality},
author = {Ivan Booth},
journal= {arXiv preprint arXiv:1510.01759},
year = {2016}
}
Comments
V3: Version accepted to PRD. Significant new material including a full analysis of junction conditions for dynamical extremal horizons (an instantaneous thin shell is now identified). Other smaller changes including extra material to clarify some points as well as fixing minor errors and typos. References added. Now 14 pages and 7 figures