Answers are grounded in this paper and cite their sources.
We present a novel theorem regarding light rings in a stationary spacetime with an ergoregion. We prove that any stationary, axisymmetric, and asymptotically flat spacetime in $1+3$ dimensions with an ergoregion must have at least one light ring outside the ergoregion. A possible extension of the proof for asymptotically de Sitter and anti--de Sitter spherically symmetric black holes is also discussed.
No takes yet. Share an insight, caveat, or question.
Ghosh et al. (2021) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: