Lola Thompson, Utrecht University
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Rémi Coulon, CNRS Rennes
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Richard Montgomery, University of California, Santa Cruz
Zoom Meeting ID: 998 6775 5871
Zoom Meeting link: https://vanderbilt.zoom.us/j/99867755871
Email mathcolloquium@vanderbilt.edu to request pass code

(Contact Person: Marcelo Disconzi)

Remi Boutonnet, CNRS, Universite de Bordeaux
Zoom Meeting ID: 975 6315 9768
Email Dietmar Bisch to request pass code

Over the past decade, extensive work on C*-simplicity of various groups has led to many breakthrough results. At the origin of this effervescence lies the study of group actions on (non-commutative) C*-algebras. In this talk, I will explain how to push this idea further to study arbitrary unitary representations of higher rank semi-simple lattices. The idea is to extend Margulis’ approach of his normal subgroup theorem via ergodic theory to the non-commutative setting. This is partially inspired by recent work of Peterson, although we use a different strategy, based on stationary dynamics and work of Nevo and Zimmer. This talk is based on joint works with Uri Bader, Cyril Houdayer and Jesse Peterson.

Nestor Guillen, Texas State University
Zoom Meeting ID: TBA

Amanda Folsom, Amherst College
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Wenhao Wang, Vanderbilt University
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The Dehn function was introduced by computer scientists Madlener and Otto to describe the complexity of the word problem of a group, and also by Gromov as a geometric invariant of finitely presented groups. In this talk, I will show that the upper bound of the Dehn function of finitely presented metabelian group G is 2n2k, where k is the torsion-free rank of the abelianization Gab, answering the question that if the Dehn functions of metabelian groups are uniformly bounded. I will also talk about the relative Dehn function of finitely generated metabelian group and its relation to the Dehn function.