Factorizations of one-generated -local formations.
Let be a finite group. We prove that if every self-centralizing subgroup of is nilpotent or subnormal or a TI-subgroup, then every subgroup of is nilpotent or subnormal. Moreover, has either a normal Sylow -subgroup or a normal -complement for each prime divisor of .
A group is said to be a -group if for every divisor of the order of , there exists a subgroup of of order such that is normal or abnormal in . We give a complete classification of those groups which are not -groups but all of whose proper subgroups are -groups.
Counting subgroups of finite groups is one of the most important topics in finite group theory. We classify the finite non-nilpotent groups whose set of numbers of subgroups of possible orders has exactly two elements. We show that if is a non-nilpotent group whose set of numbers of subgroups of possible orders has exactly 2 elements, then has a normal Sylow subgroup of prime order and is solvable. Moreover, as an application we give a detailed description of non-nilpotent groups with...
We prove that are primitive the finite groups whose normalizers of the Sylow subgroups are primitive. We classify the groups of such class, denoted by , and we study the Schunck classes whose boundary is contained in . We give also necessary and sufficient conditions in order that the projectors be subnormally embedded.
Let be a finite group, the smallest prime dividing the order of and a Sylow -subgroup of with the smallest generator number . There is a set of maximal subgroups of such that . In the present paper, we investigate the structure of a finite group under the assumption that every member of is either -permutably embedded or weakly -permutable in to give criteria for a group to be -supersolvable or -nilpotent.
A subgroup of a finite group is said to be SS-supplemented in if there exists a subgroup of such that and is S-quasinormal in . We analyze how certain properties of SS-supplemented subgroups influence the structure of finite groups. Our results improve and generalize several recent results.
Suppose G is a finite group and H is a subgroup of G. H is called weakly s-permutably embedded in G if there are a subnormal subgroup T of G and an s-permutably embedded subgroup of G contained in H such that G = HT and ; H is called weakly s-supplemented in G if there is a subgroup T of G such that G = HT and , where is the subgroup of H generated by all those subgroups of H which are s-permutable in G. We investigate the influence of the existence of s-permutably embedded and weakly s-supplemented...