The influence of weakly $S\Phi$-supplemented subgroups on fusion systems of finite groups

Abstract

Let $G$ be a finite group and $H$ be a subgroup of $G$. Then $H$ is called a weakly $S\Phi$-supplemented subgroup of $G$, if there exists a subgroup $T$ of $G$ such that $G=HT$ and $H\cap T\le \Phi (H)H_{sG}$, where $H_{sG}$ denotes the subgroup of $H$ generated by all subgroups of $H$ which are $S$-permutable in $G$. Let $p$ be a prime, $S$ be a $p$-group and $\mathcal{F}$ be a saturated fusion system over $S$. Then $\mathcal{F}$ is said to be supersolvable, if there exists a series of $S$, namely $1=S_0\le S_1\le \cdots \le S_n=S$, such that $S_{i+1}/S_i$ is cyclic, $i=0,1,\cdots ,n-1$, $S_i$ is strongly $\mathcal{F}$-closed, $i=0,1,\cdots ,n$. In this paper, we investigate the structure of fusion system ${\mathcal{F}}_S(G)$ under the assumption that certain subgroups of $S$ are weakly $S\Phi$-supplemented in $G$, and obtain several new characterizations of supersolvability of ${\mathcal{F}}_S(G)$.

arXiv admin note: text overlap with arXiv:2402.00012