The F A-prime subgroup conjecture for Artin groups

A group $G$ has property ${\rm F}\mathcal{A}'$ if every simplicial action of $G$ on a tree without inversion is locally elliptic. A subgroup is non-trivial if it is not the trivial group. The ${\rm F}\mathcal{A}'$-subgroup conjecture. Artin groups have no non-trivial ${\rm F}\mathcal{A}'$-subgroups. The paper presents this as an open extension of the corresponding known result for right-angled Artin groups.