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Colloquium by Nicolas Monod (Ecolé Polytechnique Fédérale de Lausanne)

Title: Large forests and Littlewood

2013.11.25 | Christine Dilling

Date Fri 16 Apr
Time 14:15 15:15
Location Aud D3


Motivated by a classical result of Sz.-Nagy in functional analysis, Dixmier asked in 1950 which group representations can be made unitary. This question is still open, but I will report on some progress obtained with Epstein and Ozawa. We approach the question with ideas borrowed from XIXth century electricity theory as well as from contemporary percolation theory. As a result, we obtain notably non-unitarizable representations for Burnside groups and a new characterization of amenability. The talk will be expository.