Topology Seminar

Wednesday, October 25, 2017
4:20 PM - 5:20 PM (ET)
Exley Science Center Tower ESC 638
Event Type
Canalia, Caryn

Speaker: Arie Levit, Yale

Title:  Local rigidity of uniform lattices

Abstract:  A lattice is topologically locally rigid (t.l.r) if small deformations of it are isomorphic lattices. Uniform lattices in Lie groups were shown to be t.l.r by Weil [60']. We show that uniform lattices in any compactly generated topological group are t.l.r.

 A lattice is locally rigid (l.r) if small deformations arise from conjugation. It is a classical fact due to Weil [62'] that lattices in semi-simple Lie groups are l.r. Relying on our t.l.r results and on recent work by Caprace-Monod we prove l.r for uniform lattices in the isometry groups of certain CAT(0) spaces, with the exception of SL_2(R), which occurs already in the classical case.

 In the talk I will explain the above notions and results, and present some geometric ideas from the proofs.

 This is a joint work with Tsachik Gelander.


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