机构地区: 广东教育学院
出 处: 《数学进展》 2007年第5期599-606,共8页
摘 要: 有限群G的一个子群称为在G中是π-拟正规的若它与G的每一个Sylow-子群是交换的.G的一个子群H称为在G中是c-可补的若存在G的子群N使得G=HN且H∩N≤HG=CoreG(H).本文证明了:设F是一个包含超可解群系U的饱和群系,G有一个正规子群H使得G/H∈F.则G∈F若下列之一成立:(1)H的每个Sylow子群的所有极大子群在G中或者是π-拟正规的或者是c-可补的;(2)F^*(H)的每个SyloW子群的所有极大子群在G中或者是π-拟正规的或者是c-可补的,其中F^*(H)是H的广义Fitting子群.此结论统一了一些最近的结果. A subgroup of a finite group G is called π--quasinormal in G if it permutes with every Sylow subgroup of G. A subgroup H of a group G is said to be c-supplemented in G if there exists a subgroup N of G such that G = HN and H M N ≤ HG = Corec (H). In this paper we prove: Let F- be a saturated formation containing U, the class of all supersolvable groups and suppose that G is a group with a normal subgroup H such that G/H∈F . Then G∈F if one of following holds: (1) All maximal subgroups of all Sylow subgroups of H are either π-quasinormal or c-supplemented in G; (2) All maximal subgroups of all Sylow subgroups of F^* (H), the generalized Fitting subgroup of H, are either π--quasinormal or c- supplemented in G. These unify some recent results.