Dense subgroups of simple Lie groups

Event time: 
Wednesday, November 16, 2016 - 11:15am to 12:15pm
Location: 
215 LOM
Speaker: 
Yves Benoist
Speaker affiliation: 
Université de Paris-Sud
Event description: 

Let G be a Lie group. We will focus on the following two questions.
Is the Hausdorff dimension of a Borel measurable, dense and proper
subgroup of G always zero? Is the convolution of sufficiently many
continuous functions on G always continuously differentiable?
Even though the answer to these questions is NO when G is abelian
the answer is YES when G is simple. This will follow from a
local spectral gap property. Joint work with N. de Saxce.