Black hole mergers as the fastest photon ring scramblers
Phys. Rev. D 114, 023556 – Published 23 July, 2026
DOI: https://doi.org/10.1103/q8j1-w2nr
Abstract
Black holes are the most efficient scramblers in nature. By mapping the instantaneous mass and angular momentum of two spinless black holes in a quasicircular binary onto those of an effective Kerr black hole, we demonstrate that the final state of the merger remnant corresponds with remarkable accuracy to the configuration that renders null geodesics unstable at the highest possible rate. This suggests a deep connection between the properties of black holes resulting from binary mergers and their unstable null orbits.
