Work

Expansion in simple groups

Year: 2018
Type: preprint
Abstract: Two short seminal papers of Margulis used Kazhdan's property $(T)$ to give, on the one hand, explicit constructions of expander graphs, and to prove, on the other hand, the uniqueness of some invariant means on compact simple Lie groups. These papers opened a rich line of research on expansion and spectral gap phenomena in finite and compact simple groups. In this paper we survey the history of this area and point out a number of problems which are still open.
Language: English
Open Access status: green
OpenAlex ID: W2830897620
Cites: 64
Cited by: 6
Related to: 20