We survey recent results concerning local rigidity of lattices in semisimple Lie groups and characterize the deformability of surface groups in semisimple Lie groups in terms of balanced conditions on root spaces. This is a joint work with Pierre Pansu.
Links:
[1] http://www.mpim-bonn.mpg.de/de/taxonomy/term/39
[2] http://www.mpim-bonn.mpg.de/de/node/3444
[3] http://www.mpim-bonn.mpg.de/de/node/158