English

Observability of spherical photon orbits in near-extremal Kerr black holes

General Relativity and Quantum Cosmology 2019-09-04 v2 High Energy Astrophysical Phenomena High Energy Physics - Theory

Abstract

We investigate the spherical photon orbits in near-extremal Kerr spacetimes. We show that the spherical photon orbits with impact parameters in a finite range converge on the event horizon. Furthermore, we demonstrate that the Weyl curvature near the horizon does not generate the shear of a congruence of such light rays. Because of this property, a series of images produced by the light orbiting around a near-extremal Kerr black hole several times can be observable.

Keywords

Cite

@article{arxiv.1904.00271,
  title  = {Observability of spherical photon orbits in near-extremal Kerr black holes},
  author = {Takahisa Igata and Hideki Ishihara and Yu Yasunishi},
  journal= {arXiv preprint arXiv:1904.00271},
  year   = {2019}
}

Comments

12 pages, 3 figures; v2: published version