On the linearity of lattices in affine buildings (Geometry Day)
 Date:18.11.2016
 Speaker:Jean Lécureux
 Time:11:30  12:30 Uhr

Abstract: Affine buildings are mostly useful because they admit nice actions by simple algebraic groups over local fields. However, there are some other constructions of 2dimensional affine buildings, some of them with cocompact automorphism group.
After recalling the basic definitions and facts about affine buildings, I will explain the following theorem: a cocompact automorphism group of an $\tilde A_2$building admits an infinite linear representation if and only if it is arithmetic. The proof uses ergodic techniques à la Margulis.
It is a joint work with Uri Bader and PierreEmmanuel Caprace.
 Place:SR 0.014 (20.30)