Uploaded July 2026 | Updated September 2026, 3 days ago
The 25th Midrasha Mathematicae on Groups, Expanders and Codes -- Celebrating Alex Lubotzky's 70th birthday.
Day 4, Session 3
Speaker: Benny Bachner (Weizmann)
Title: On L^p approximations and stability for groups
Abstract: In this talk, I will introduce the general framework for metric approximations for groups and the related notion of stability. We will survey results from recent years about groups not approximable by the p-Schatten norm, 1p\infty, relying on higher property (T) for these groups. We extend this to the case p=1 and discuss the open case of p=\infty, corresponding to the major open problem of a non-MF group. Based on joint work with Alon Dogon and Alex Lubotzky
The 25th Midrasha Mathematicae on Groups, Expanders and Codes -- Celebrating Alex Lubotzky's 70th birthday.
Day 4, Session 3
Speaker: Benny Bachner (Weizmann)
Title: On L^p approximations and stability for groups
Abstract: In this talk, I will introduce the general framework for metric approximations for groups and the related notion of stability. We will survey results from recent years about groups not approximable by the p-Schatten norm, 1p\infty, relying on higher property (T) for these groups. We extend this to the case p=1 and discuss the open case of p=\infty, corresponding to the major open problem of a non-MF group. Based on joint work with Alon Dogon and Alex Lubotzky
