During the academic year 2016-2017, Romain Tessera and I organized the weekly seminar Groups, Actions and von Neumann algebras at the Université Paris-Sud, Orsay.

The seminar featured both research and introductory talks on topics including geometric and measured group theory, ergodic theory and von Neumann algebras.

Meetings

Monday October 10

Cyril Houdayer (Université Paris-Sud)

Character rigidity for higher rank lattices I (after Peterson)

Monday October 17

Amine Marrakchi (Université Paris-Sud)

Character rigidity for higher rank lattices II (after Peterson)

Monday November 7

Amaury Freslon (Université Paris-Sud)

Character rigidity for higher rank lattices III (after Peterson)

Monday November 14

Peter Verraedt (Université Paris-Sud)

Character rigidity for higher rank lattices IV (after Peterson)

Monday November 28

Cyril Houdayer (Université Paris-Sud)

On the type I conjecture for locally compact groups acting properly on trees

Monday December 5

Jean-Baptiste Boyer (Université Paris-Sud)

Perturbation of a Markov operator on the projective space

Monday December 12

Anna Sofie Krogager (KU Leuven)

Thin II₁ factors with no Cartan subalgebras

Monday January 9

Jean Lécureux (Université Paris-Sud)

Nonlinearity for the groups of affine buildings of type Ã₂

Monday January 30

Masato Mimura (Tohoku University and EPFL)

Synthesis of fixed points and trace class ideal

Monday February 13

Arielle Leitner (Technion)

Transitions of the diagonal Cartan subgroup in SL(n,R)

Monday February 20

Clément Toromanoff (Laboratoire Paul Painlevé)

Convergence groups and Specker compactifications

Monday May 29

Camille Horbez (CNRS and Université Paris-Sud)

Amenability at infinity of Out(Fn)

Monday June 26

Anne Lonjou (Institut de Mathématiques de Toulouse)

Cremona group and Voronoi paving