The Kijowski--Liu--Yau quasi-local mass of the Kerr black hole horizon
arXiv:2107.12400 · doi:10.1088/1361-6382/ac2cb6
Abstract
We use the isometric embedding of the spatial horizon of fast rotating Kerr black hole in a hyperbolic space to compute the quasi-local mass of the horizon for any value of the spin parameter . The mass is monotonically decreasing from twice the ADM mass at to at . It then monotonicaly increases to a maximum around , and finally decreases to for which corresponds to the extreme Kerr black hole.
9 pages. Dedicated to Gary Gibbons on the occasion of his 75th birthday. Numerical methods used in the paper clarified. Final version, to appear in Classical and Quantum Gravity