有限生成无挠幂零群的4阶自同构

Finitely Generated Torsion-Free Nilpotent Groups Admitting an Automorphism of Order Four

设G是有限生成无挠幂零群,α是G的4阶自同构且 是满射,则G的二阶导群G'' 包含在G的中心Z(G) 里且CG(α2) 是Abel群。

Let G be a finitely generated torsion-free nilpotent group and α an automorphism of order four of G. If the map G→G defined by is surjective, then the second derived subgroup G'' is included in the centre of G and CG(α2) is abelian.