Mach's Principle, the Kerr Metric, and Black-Hole Physics

The generalized Kerr solution is tentatively accepted as the description for the state of a charged rotating mass which has undergone complete gravitational collapse. Mass accretion by such a system is demonstrated to damp out the rotation. Even the most favorable selective capture of matter leaves the angular momentum bounded by $m^2$, precisely the upper limit that the Kerr geometry can accommodate without change of character. Mach's principle, exemplified by the rotation of inertial frames, is employed to obtain approximate expressions for perihelion precession of satellites, deflection of light trajectories, and the rotation of polarization of light. Results are compared with exact expressions, when available.