ON THE PRE-HORIZON REGIME IN THE KERR METRIC

Sufficiently close to an event horizon an increase in the angular velocity induces more gravitational attraction than centrifugal repulsion on a circularly orbiting particle. At the same time the local compass of inertia tends to precess forward with respect to the sense of the orbital rotation, rather than backwards. A spacetime which gives rise to these effects is termed to be in a pre-horizon regime. Here we investigate the occurrence of this regime in the Kerr metric.