BEAM COLLIMATION LIGHT DEFLECTION AND TIME-DELAY IN THE KERR SPACETIME

By using an alternative method valid in weak and strong gravitational fields, we study beam collimation, light bending and time delays in th e equatorial Kerr spacetime. Three applications are carried out. First , it is shown that the interaction ''spin-orbit'' could collimate a be am only if the particle or photon moves in a opposite direction to the compact object's spin. Secondly, the deflection angles of light rays gracing a quasar, a pulsar (PSR 1937+214), and a rotating black hole a re computed and compared with approximate solutions. Finally, we calcu late the photon's time delay traveling from SN1987A to Earth. The resu lt of this undertaking is compared with a similar calculation using th e PPN formalism.