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Download fileBoundaries, Weyl groups, and Superrigidity
journal contribution
posted on 2012-08-17, 00:00 authored by Uri Bader, Alex FurmanThis note describes a unified approach to several superrigidity results, old and new, concerning representations of lattices into simple algebraic groups over local fields. For an arbitrary group Γ and a boundary action Γ B we associate a certain generalized Weyl group WΓ,B and show that
any representation with a Zariski dense unbounded image in a simple algebraic
group, ρ : Γ → H, defines a special homomorphism WΓ,B → WeylH. This
general fact allows the deduction of the aforementioned superrigidity results.