REPULSIVE GRAVITATION IN THE KERR-NEWMAN FIELD

It is shown that uncharged test particles, released from rest at infin ity in the Kerr-Newman field, stop and rebound when the radial coordin ate r takes the value r(o) = Q(2)/(2M). This expression corresponds to the position of a stationary source of the Kerr-Newman field found by the author. It represents the surface of a massive oblate ellipsoid o f revolution undergoing rigid rotation. Besides, the magnitude of r(o) guarantees that no violation of causality occurs throughout spacetime . Although the test particles' angular momenta are always zero, they a cquire a rotational motion as a consequence of the dragging of inertia l frames.