Humpy LNRF-velocity profiles in accretion discs orbiting rapidly rotating Kerr black holes: a possible relation to epicyclic oscillations

摘要

Coordinate-independent definition of the characteristic, so-called "humpy" frequency related to the positive gradient of the orbital velocity in locally non-rotating frames around nearly extreme Kerr black holes is given and compared with the epicyclic and orbital frequencies for both Keplerian thin discs and limiting marginally stable thick discs.