Abstract
It is proved that spherically symmetric extremal black holes possess at least one external light ring. Our remarkably compact proof is based on the dominant energy condition which characterizes the external matter fields in the nonvacuum asymptotically flat extremal black-hole spacetimes.
- Received 28 November 2022
- Accepted 6 January 2023
DOI:https://doi.org/10.1103/PhysRevD.107.024028
© 2023 American Physical Society
Physics Subject Headings (PhySH)
Gravitation, Cosmology & Astrophysics
