http://arxiv.org/abs/2001.06100
The general parametrization of a black-hole spacetime in arbitrary metric theories of gravity includes an infinite set of parameters. It is natural to suppose that essential astrophysically observable quantities, such as quasinormal modes, parameters of shadow, electromagnetic radiation and accreting matter in the vicinity of a black hole, must depend only on a few of these parameters. Starting from the parametrization for spherically symmetric configurations in the form of infinite continued fraction, we suggest a compact representation of the asymptotically flat spherically symmetric and slowly rotating black holes in terms of only three and four parameters respectively. This approximate representation of a black-hole metric should allow one to describe physical observables in the region of strong gravity.
R. Konoplya and A. Zhidenko
Mon, 20 Jan 20
57/60
Comments: 5 pages, 1 figure