Hi everybody, Around a black hole, a test particle can experience two types precession: of its pericenter and of its angular momentum vector. I would like to know if there exist an EXACT expression for the rate at which these two precession occurs both for a Schwarzchild and a Kerr black hole for a given orbit (with known energy and angular momentum vector). If I am not mistaken, such expressions exist for a Schwarzchild black hole. In this case, there is no precession of the angular momentum vector (the orbit is planar) and the apsidal precession rate is obtained through an elliptical integral. However, I am not sure about the case of a Kerr black hole. Could you help me with my problem? Also, I was wondering if there exist a freely accessible program to compute such orbits. Thank you in advance.