Constructing irreducible representations of discrete groups

Burger, Marc ; De La Harpe, Pierre

In: Proceedings of the Indian Academy of Sciences - Mathematical Sciences, 1997, vol. 107, no. 3, p. 223-235

Add to personal list
    Summary
    The decomposition of unitary representations of a discrete group obtained by induction from a subgroup involves commensurators. In particular Mackey has shown that quasi-regular representations are irreducible if and only if the corresponding subgroups are self-commensurizing. The purpose of this work is to describe general constructions of pairs of groups Γ0 with Γ its own commensurator in Γ. These constructions are then applied to groups of isometries of hyperbolic spaces and to lattices in algebraic groups