Finite groups with generalized Ore supplement conditions for primary subgroups
We consider some applications of the theory of generalized Ore supplement conditions in the study of finite groups.
arXiv subjects
Publications and source records attributed to Wenbin Guo.
We consider some applications of the theory of generalized Ore supplement conditions in the study of finite groups.
Let $π$ be a set of primes. By H.Wielandt definition, {\it Sylow $π$-theorem} holds for a finite group $G$ if all maximal $π$-subgroups of $G$ are conjugate. In the paper, the following statement is proven. Assume that $π$ is a union of disjoint subsets $σ$ and $τ$ and a finite group $G$ possesses a $π$-Hall subgroup which is a direct product of a $σ$-subgroup and a $τ$-subgroup. Furthermore, assume that both the Sylow $σ$-theorem and $τ$-theorem hold for $G$. Then the Sylow $π$-theorem holds for $G$. This result confirms a conjecture posed by H.\,Wielandt in~1959.
Let $\mathfrak{F}$ be a formation and $G$ a finite group. A subgroup $H$ of $G$ is said to be weakly $\mathfrak{F}_{s}$-quasinormal in $G$ if $G$ has an $S$-quasinormal subgroup $T$ such that $HT$ is $S$-quasinormal in $G$ and $(H\cap T)H_{G}/H_{G}\leq Z_{\mathfrak{F}}(G/H_{G})$, where $Z_{\mathfrak{F}}(G/H_{G})$ denotes the $\mathfrak{F}$-hypercenter of $G/H_{G}$. In this paper, we study the structure of finite groups by using the concept of weakly $\mathfrak{F}_{s}$-quasinormal subgroups.
A subgroup $H$ of a finite group $G$ is said to be SS-permutable in $G$ if $H$ has a supplement $K$ in $G$ such that $H$ permutes with every Sylow subgroup of $K$. A finite group $G$ is called an SST-group if SS-permutability is a transitive relation on the set of all subgroups of $G$. The structure of SST-groups is investigated in this paper.
Let $\mathfrak{H}$ be a Fitting class and $\mathfrak{F}$ a formation. We call a subgroup $\mathcal{N}_{\mathfrak{H},\mathfrak{F}}(G)$ of a finite group $G$ the $\mathfrak{H}$-$\mathfrak{F}$-norm of $G$ if $\mathcal{N}_{\mathfrak{H},\mathfrak{F}}(G)$ is the intersection of the normalizers of the products of the $\mathfrak{F}$-residuals of all subgroups of $G$ and the $\mathfrak{H}$-radical of $G$. Let $π$ denote a set of primes and let $\mathfrak{G}_π$ denote the class of all finite $π$-groups. We call the subgroup $\mathcal{N}_{\mathfrak{G}_π,\mathfrak{F}}(G)$ of $G$ the $π\mathfrak{F}$-norm of $G$. A normal subgroup $N$ of $G$ is called $π\mathfrak{F}$-hypercentral in $G$ if either $N=1$ or $N>1$ and every $G$-chief factor below $N$ of order divisible by at least one prime in $π$ is $\mathfrak{F}$-central in $G$. Let $Z_{π\mathfrak{F}}(G)$ denote the $π\mathfrak{F}$-hypercentre of $G$, that is, the product of all $π\mathfrak{F}$-hypercentral normal subgroups of $G$. In this paper, we study the properties of the $\mathfrak{H}$-$\mathfrak{F}$-norm, especially of the $π\mathfrak{F}$-norm of a finite group $G$. In particular, we investigate the relationship between the $π'\mathfrak{F}$-norm and the $π\mathfrak{F}$-hypercentre of $G$.
Let $\frak{F}$ be a class of finite groups. A subgroup $H$ of a finite group $G$ is said to be $\mathfrak{F_{\mathrm s}}$-quasinormal in $G$ if there exists a normal subgroup $T$ of $G$ such that $HT$ is $s$-permutable in $G$ and $(H\cap T)H_G/H_G$ is contained in the $\frak{F}$-hypercenter $Z_\infty^\mathfrak{F}(G/H_G)$ of $G/H_G$. In this paper, we investigate further the influence of $\mathfrak{F_{\mathrm s}}$-quasinormality of some subgroups on the structure of finite groups. New characterization of some classes of finite groups are obtained.
A subgroup $H$ of a finite group $G$ is said to satisfy $Π$-property in $G$ if for every chief factor $L/K$ of $G$, $|G/K:N_{G/K}(HK/K\cap L/K)|$ is a $π(HK/K\cap L/K)$-number. A subgroup $H$ of $G$ is called to be $Π$-supplemented in $G$ if there exists a subgroup $T$ of $G$ such that $G=HT$ and $H\cap T\leq I\leq H$, where $I$ satisfies $Π$-property in $G$. In this paper, we investigate the structure of a finite group $G$ under the assumption that some primary subgroups of $G$ are $Π$-supplemented in $G$. The main result we proved improves a large number of earlier results.
Let $G$ be a finite group. A subgroup $H$ of $G$ is said to be weakly S-embedded in $G$ if there exists $K\unlhd G$ such that $HK$ is S-quasinormal in $G$ and $H\cap K\leq H_{seG}$, where $H_{seG}$ is the subgroup generated by all those subgroups of $H$ which are S-quasinormally embedded in $G$. We say that $H$ is weakly $τ$-embedded in $G$ if there exists $K\unlhd G$ such that $HK$ is S-quasinormal in $G$ and $H\cap K\leq H_{τG}$, where $H_{τG}$ is the subgroup generated by all those subgroups of $H$ which are $τ$-quasinormal in $G$. In this paper, we study the properties of the weakly S-embedded subgroups and the weakly $τ$-embedded subgroups, and use them to determine the structure of finite groups.
In the paper new criteria of existence and conjugacy of Hall subgroups of finite groups are given.
Let $\cal F$ be a class of groups. A chief factor $H/K$ of a group $G$ is called \emph{${\cal F}$-central in $G$} provided $(H/K)\rtimes (G/C_{G}(H/K)) \in {\cal F}$. We write $Z_{π{\cal F}}(G)$ to denote the product of all normal subgroups of $G$ whose $G$-chief factors of order divisible by at least one prime in $π$ are $\cal F$-central. We call $Z_{π{\cal F}}(G)$ the $π{\cal F}$-hypercentre of $G$. A subgroup $U$ of a group $G$ is called \emph{$\cal F$-maximal} in $G$ provided that (a) $U\in {\cal F}$, and (b) if $U\leq V\leq G$ and $V\in {\cal F}$, then $U=V$. In this paper we study the properties of the intersection of all $\cal F$-maximal subgroups of a finite group. In particular, we analyze the condition under which $Z_{π{\cal F}}(G)$ coincides with the intersection of all $\cal F$-maximal subgroups of $G$.