3 problems

Let $\mathcal{G}$ be a Hausdorff étale groupoid. Weak amenability means that $\Lambda_{\text{cb}}(\mathcal{G})$ is finite, and the condition $\Lambda_{\text{cb}}(\mathcal{G})=1$ is…

Let $G$ be a locally compact group. The one-way Cowling conjecture. If $G$ is weakly amenable with $\boldsymbol\Lambda(G)=1$, then it has the Haagerup property. This is the directi…

Let $G$ be a locally compact group. The Haagerup property equivalence conjecture. $G$ has the Haagerup property if and only if $G$ is weakly amenable with $\boldsymbol\Lambda(G)=1$…