Abstract

Null and time-like geodesics around a 2+1 black hole are determined. Complete geodesics of both types exist in the rotating black-hole background, but not in the spinless case. Upper and lower bounds for the radial size of the orbits are given in all cases and the possibility of passing from one black-hole exterior spacetime to another is discussed using Penrose diagrams. An analysis of particle motions by means of effective potentials and orbit graphs is also included.