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arXiv · 1904.00271

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

Takahisa Igata·Hideki Ishihara·Yu Yasunishi
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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.

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Takahisa Igata, Hideki Ishihara, Yu Yasunishi. 2019-09-01. Observability of spherical photon orbits in near-extremal Kerr black holes. https://doi.org/10.1103/physrevd.100.044058

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