THE INEQUALITY BETWEEN MASS AND ANGULAR MOMENTUM FOR AXIALLY SYMMETRIC BLACK HOLES

Abstract

In this essay I first discuss the physical relevance of the inequality [Formula: see text] for axially symmetric (nonstationary) black holes, where m is the mass and J the angular momentum of the space–time. Then, I present a proof of this inequality for the case of one spinning black hole. The proof involves a remarkable characterization of the extreme Kerr black hole as an absolute minimum of the total mass. Finally, I conjecture about the physical implications of this characterization for the nonlinear stability problem for black holes.