The BTZ black hole violates strong cosmic censorship
Abstract
We investigate the stability of the inner horizon of a rotating BTZ black hole. We show that linear perturbations arising from smooth initial data are arbitrarily differentiable at the inner horizon if the black hole is sufficiently close to extremality. This is demonstrated for scalar fields, for massive Chern-Simons fields, for Proca fields, and for massive spin-2 fields. Thus the strong cosmic censorship conjecture is violated by a near-extremal BTZ black hole in a large class of theories. However, we show that a weaker "rough" version of the conjecture is respected. We calculate the renormalized energy-momentum tensor of a scalar field in the Hartle-Hawking state in the BTZ geometry. We show that the result is finite at the inner horizon of a near-extremal black hole. Hence the backreaction of vacuum polarization does not enforce strong cosmic censorship.
Keywords
Cite
@article{arxiv.1906.08265,
title = {The BTZ black hole violates strong cosmic censorship},
author = {Oscar J. C. Dias and Harvey S. Reall and Jorge E. Santos},
journal= {arXiv preprint arXiv:1906.08265},
year = {2020}
}
Comments
59 pages, 9 figures. Changes in v2: 1) a few discussions added/improved, 2) added Section 5.8 discussing the non-smoothness of the Hartle-Hawking state at the Cauchy horizon