Title

Nearly extremal apparent horizons in simulations of merging black holes

Abstract

The spin angular momentum S of an isolated Kerr black hole is bounded by the surface area A of its apparent horizon: 8 pi S A. We show that the overspun surfaces are indeed superextremal: our lower bound on their Booth-Fairhurst extremality exceeds unity. However, we confirm that these superextremal surfaces are always surrounded by marginally outer trapped surfaces (i.e., by apparent horizons) with 8 pi S < A. The extremality lower bound on the enclosing apparent horizon is always less than unity but can exceed the value for an extremal Kerr black hole.

Publisher

IOP Publishing

Publication Date

3-19-2015

Publication Title

Classical and Quantum Gravity

Department

Physics and Astronomy

Document Type

Article

DOI

10.1088/0264-9381/32/6/065007

Keywords

Numerical relativity, Black hole binaries, Extremality, Apparent horizon

Language

English

Format

text

Share

COinS