Sound horizon of accretion onto a Kerr black hole
Two accretion modes (disclike and Bondi type), based on a discontinuous change in location of the sound horizon, exist generally for accretion onto a Kerr black hole, except for the case of a corotating accretion flow onto a very rapidly rotating hole, in which only Bondi-type mode is possible.
scientific article; zbMATH DE number 3920145