Fermat's principle in black-hole spacetimes

Abstract

Black-hole spacetimes are known to possess closed light rings. We here present a remarkably compact theorem which reveals the physically intriguing fact that these unique null circular geodesics provide the {\it fastest} way, as measured by asymptotic observers, to circle around spinning Kerr black holes.

arXiv comment5 pages. This essay received an Honorable Mention in the 2018 Essay Competition of the Gravity Research Foundation

References in corpus (1)

• The fastest way to circle a black hole

Cited by in corpus (5)

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• Fixed energy solutions to the Euler-Lagrange equations of an indefinite Lagrangian with affine Noether charge
• Fermat's principle in constant gravitational field