Fermat's principle in constant gravitational field
arXiv:2106.10965 · doi:10.1142/S0218271821500942
Abstract
Recently (Int.Journ.Mod.Phys. D27 (2018), 1847025) an interesting property of closed light rings in Kerr black holes has been noticed. We explain its origin and derive a slightly more general result.
4 pages, 1 figure