Transition from inspiral to plunge for a compact body in a circular equatorial orbit around a massive, spinning black hole - art. no. 124022

There are three regimes of gravitational-radiation-reaction-induced inspira l for a compact body with mass mu, in a circular, equatorial orbit around a Kerr black hole with mass M>>mu: (i) the adiabatic inspiral regime, in whi ch the body gradually descends through a sequence of circular, geodesic orb its; (ii) a transition regime, near the innermost stable circular orbit (is co); (iii) the plunge regime, in which the body travels on a geodesic from slightly below the isco into the hole's horizon. This paper gives an analyt ic treatment of the transition regime and shows that, with some luck, gravi tational waves from the transition might be measurable by the space-based L ISA mission.