English

Extremality conditions for isolated and dynamical horizons

General Relativity and Quantum Cosmology 2008-11-26 v3

Abstract

A maximally rotating Kerr black hole is said to be extremal. In this paper we introduce the corresponding restrictions for isolated and dynamical horizons. These reduce to the standard notions for Kerr but in general do not require the horizon to be either stationary or rotationally symmetric. We consider physical implications and applications of these results. In particular we introduce a parameter e which characterizes how close a horizon is to extremality and should be calculable in numerical simulations.

Keywords

Cite

@article{arxiv.0708.2209,
  title  = {Extremality conditions for isolated and dynamical horizons},
  author = {Ivan Booth and Stephen Fairhurst},
  journal= {arXiv preprint arXiv:0708.2209},
  year   = {2008}
}

Comments

13 pages, 4 figures, added reference; v3 appendix added with proof of result from section IIID, some discussion and references added. Version to appear in PRD

R2 v1 2026-06-21T09:07:59.521Z