Ergodic Theory and Topological Dynamics of Group Actions on Homogeneous Spaces

This book first published in 2000 is a self-contained and elementary as possible. It includes an elementary and complete proof (due to Margulis and Dani) of Oppenheim''s conjecture plus an exposition of Ratner''s work on Raghunathan''s conjectures and a new treatment of Mautner''s result on the geodesic flow of a Riemannian symmetric space.