Geometric Property (T)

Lundi 10 décembre 2018 14:00-15:00 - Thiebout Delabie - Université Paris-Sud

Résumé : Box spaces are metric spaces created using a group and a sequence of finite index normal subgroups. There are many relations between the properties of the box space and properties of the group that was used to create them. Most notably, Margulis showed that box spaces of groups with property (T) are expanders. However not all box spaces that are expanders are created by a group with property (T).
So being an expander does not tell you if a box space was created using a group with property (T), but there exists a property that does. In 2013 Willett and Yu introduced geometric property (T) and showed that a box space has geometric property (T) if and only if the group has property (T).

Lieu : Salle 2P8

Geometric Property (T)  Version PDF