Discrete subgroups of isometries in complex hyperbolic space

The goal of this talk is to present results and examples about discrete subgroups of PU(2,1), which is the automorphism group of the complex hyperbolic plane. These groups are a complex 2-dimensional analogue of Fuchsian groups in PSL(2,R), or Kleinian groups in PSL(2,C). The complex hyperbolic space is an example of a rank one symmetric space with negative pinched curvature. It is biholomorphic to a ball, and is a natural generalisation of the usual Poincaré disk or upper half plane. I will try to illustrate on examples the differences between the "classical" cases of Fuchsian and Kleinian groups and the complex hyperbolic case.