Kerr-Newman black hole in the formalism of isolated horizons

TL;DR

This paper constructs a Bondi-like tetrad for the Kerr-Newman black hole in the weakly isolated horizon framework, providing a non-perturbative, off-horizon description that enhances understanding of black hole geometries.

Contribution

It explicitly constructs a Bondi-like tetrad in Kerr-Newman spacetime, extending the weakly isolated horizon formalism off the horizon in a non-perturbative manner.

Findings

Explicit, non-perturbative Bondi-like tetrad constructed

All Newman-Penrose scalars computed for the tetrad

Completes off-horizon description of Kerr-Newman black hole

Abstract

The near horizon geometry of general black holes in equilibrium can be conveniently characterized in the formalism of weakly isolated horizons in the form of the Bondi-like expansions (Krishnan B, Class.\ Quantum Grav.\ 29, 205006, 2012). While the intrinsic geometry of the Kerr-Newman black hole has been extensively investigated in the weakly isolated horizon framework, the off-horizon description in the Bondi-like system employed by Krishnan has not been studied. We extend Krishnan's work by explicit, non-perturbative construction of the Bondi-like tetrad in the full Kerr-Newman spacetime. Namely, we construct the Bondi-like tetrad which is parallelly propagated along a nontwisting null geodesic congruence transversal to the horizon and provide all Newman-Penrose scalars associated with this tetrad. This work completes the description of the Kerr-Newman spacetime in the formalism of weakly isolated horizons and is a starting point for the investigation of deformed black holes.