Non-inner automorphisms of order $p$ in finite $p$-groups admitting cyclic center
Xuesong Ma, Wei Xu
TL;DR
The paper addresses the existence of non-inner automorphisms of order $p$ in finite non-abelian $p$-groups with cyclic center under a centralizer condition. It develops a derivation- and cohomology-based framework, including CR-modules and $H^1$-type analyses, to construct automorphisms of order $p$ from nontrivial derivations. The main contribution is a specific sufficient condition, $C_G(Z( olimits olinebreak ( olimits olinebreak ) )) leq $, under which such automorphisms exist, extending prior results (e.g., Marian) and providing a cohesive method to produce order-$p$ automorphisms in broad classes of $p$-groups. This advances the understanding of Gaschütz-type questions by connecting central structure, derivations, and automorphism generation in a unified approach.
Abstract
Let $G$ be a finite non-abelian $p$-group admitting cyclic center and $p$ be an odd prime. In this paper, we prove that if $C_{G}(Z(γ_{3}(G)G^{p}))\nleqslantγ_{3}(G)G^{p}$, then $G$ has a non-inner automorphism of order $p$.
