Extremal black holes have external light rings
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.
- Publication:
-
Physical Review D
- Pub Date:
- January 2023
- DOI:
- arXiv:
- arXiv:2211.15983
- Bibcode:
- 2023PhRvD.107b4028H
- Keywords:
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- General Relativity and Quantum Cosmology;
- Astrophysics - High Energy Astrophysical Phenomena;
- High Energy Physics - Theory
- E-Print:
- 9 pages