Amenability of Thompson's group F
Determine whether Thompson's group F is amenable.
References
For example, $T$ and $V$ are the first examples of finitely presented, infinite, and simple, and it is known that the amenability of $F$ is a difficult open problem.
                — Divergence functions of higher-dimensional Thompson's groups
                
                (2405.19923 - Kodama, 30 May 2024) in Section 1, Introduction