有限群子群的几点结论

对有限群子群的刻划一直是有限群论的重要研究内容 .我们在本文中利用群阶、群直积对有限群的子群作了些探讨 ,得到了几点结论 .文中符号及术语均见〔1〕 .

具有给定Sylow-子群正规化子的有限群

本文研究了部分Sylow-子群的正规化子属于某群系且具有给定指数的有限{ p,q}-可解群,利用Sylow-子群正规化子的性质,获得了相关群的一个分类定理,并给出了若干推论.

特征为0域上线性群的有限子群的界定

将Schur的线性群GL(n,Q)上扭子群必为有限群这一性质推广到Q的一般有限扩域F上,证明了GL(n,F)中方次数有限的子群的阶仅与n和[F:Q]有关.

Strongly Modular Subgroup in Finite Group

In this peper,strongly Modular subgroups was defined and studied.

Carter subgroups of singular classical groups over finite fields

Let F q be a finite field with qelements where q=p~α. In the present paper, the authors study the existence and structure of Carter subgroups of singular symplectic group Sp (n+t,n)(F q), singular unitary group U (n+t,n)(F (q^2)) and singular orthogonal group O (n+t,n)(F q)(n is even) over finite fields F q.

Construction of some hypergroups from combinatorial structures

Jajcay's studies( 1993 ; 1994) on the automorphism groups of Cayley maps yielded a new product of groups, which he called, rotary product. Using this product, we define a hyperoperation ⊙ on the group Syme (G) , the stabilizer of the identity e ∈ G in the group Sym (G) . We prove that ( Syme (G) , ⊙) is a hypergroup and characterize the subhypergroups of this hypergroup.Finally, we show that the set of all subhypergroups of Syme ( G ) constitute a lattice under ordinary join and meet and that the minimal elements of order two of this lattice is a subgroup of Aut (G) .

Finite Groups with only S-seminormal or Selfnormal Subgroups

In this note the author studies such a finite group in which each subgroup is either Sseminormal or selfnormal and characterizes this kind of finite groups.Moreover,the main results in[1] and [2] can be obtained by the conclusion in this note.

On Subsemi-Ideal Rings

In this note we introduce a new ideal called subsemi-ideal of a ring R. We obtain a necessary and sufficient condition for a group ring to be a subsemi ideal ring.

A characteristic condition of finite nilpotent group

This paper gives a characteristic condition of finite nilpotent group under the assumption that all minimal subgroups of G are well-suited in G.

On the Product of Two Nilpotent Subgroups of a Finite Group

It is known that the product of two nilpotent subgroups of a finite group is not necessarily nilpotent.In this paper, we study the influence of the Engel condition on the product of two nilpotent subgroups. Our results generalize some well-known results.

Finite Groups whose Abelian Subgroup Orders Are Consecutive Integers

In this paper we give a complete classification of finite groups whose proper abelian subgroup orders are consecutive integers.

π Frattini Subgroup and π Local Formation *

In this paper, our purpose is to make the results about π Frattini subgroup more accurate, and to extend Gaschütz Theorem about nilpotency to π locally defined formation. We come to Theorem Let G be a finite group, H a subnormal subgroup of G. If H/H∩Φ(G)O π′ (G)∈F, then H∈F π, where F π is π solvable π locally defined formation.

AUTOMORPHISM GROUPS OF 4-VALENT CONNECTED CAYLEY GRAPHS OF p-GROUPS

Let G be a p-group (p odd prime) and let X = Cay(G, S) be a 4-valent connected Cayley graph. It is shown that if G has nilpotent class 2, then the automorphism group Ant(X) of X is isomorphic to the semidirect product GR x Ant(G,S), where GR is the right regular representation of G and Aut(G,S) is the subgroup of the automorphism group Aut(G) of G which fixes S setwise. However the result is not true if G has nilpotent class 3 and this paper provides a counterexample.

A generalized CAP-subgroup of a finite group

Let A be a subgroup of a finite group G. We say that A is a generalized CAP-subgroup of G if for each chief factor H/K of G either A avoids H/K or the following holds:(1) If H/K is non-abelian, then|H :(A ∩H)K | is a p′-number for every p ∈π((A ∩H)K/K);(2) If H/K is a p-group, then |G : NG(K(A ∩H))| is a p-number. In this paper, we use the generalized CAP-subgroup to characterize the structure of finite groups.Some new characterizations of the hypercyclically embedded subgroups of a finite group are obtained and a series of known results are generalized.

On SS-quasinormal subgroups and the structure of finite groups

A subgroup H of a finite group G is said to be an SS-quasinormal subgroup of G if there is a subgroup B of G such that G = HB and H permutes with every Sylow subgroup of B. In this paper, we investigate the structure of a group under the assumption that every subgroup with order pm of a Sylow p-subgroup P of G is SS-quasinormal in G for a fixed positive integer m. Some interesting results related to the p-nilpotency and supersolvability of a finite group are obtained. For example, we prove that G is p-nilpotent if there is a subgroup D of P with 1 < |D| < |P| such that every subgroup of P with order |D| or 2|D| whenever p = 2 and |D| = 2 is SS-quasinormal in G, where p is the smallest prime dividing the order of G and P is a Sylow p-subgroup of G.

Finite groups whose maximal subgroups of sylow p-subgroups admit a p-solvable supplement

In this note,we show that if every maximal subgroup of a Sylow p-subgroup of a finite group has a p-solvable supplement then the group is necessarily p-solvable.This gives a positive answer to Problem 17.111 of the Kourovka Notebook(Unsolved Problems in Group Theory),which was posed by Skiba.

Finite p-groups with a minimal non-abelian subgroup of index p(Ⅱ)

We classify completely three-generator finite p-groups G such that Ф(G)≤Z(G)and|G′|≤p2.This paper is a part of the classification of finite p-groups with a minimal non-abelian subgroup of index p,and solve partly a problem proposed by Berkovich.

On weakly S-embedded subgroups of finite groups

Let H be a subgroup of a group G. Then H is said to be S-quasinormal in G if HP = PH for every Sylow subgroup P of G; H is said to be S-quasinormally embedded in G if a Sylow p-subgroup of H is also a Sylow p-subgroup of some S-quasinormal subgroup of G for each prime p dividing the order of H. In this paper, we say that H is weakly S-embedded in G if G has a normal subgroup T such that HT is an S-quasinormal subgroup of G and H VIT ≤ HSE, where HSE denotes the subgroup of H generated by all those subgroups of H which are S-quasinormally embedded in G. Some results about the influence of weakly S-embedded subgroups on the structure of finite groups are given.

On S-Semipermutable Subgroups of Finite Groups

Let d be the smallest generator number of a finite p-group P and let Md(P) = {P1,...,Pd} be a set of maximal subgroups of P such that ∩di=1 Pi = Φ(P). In this paper, we study the structure of a finite group G under the assumption that every member in Md(Gp) is S-semipermutable in G for each prime divisor p of |G| and a Sylow p-subgroup Gp of G.

ON COMPLEMENTED SUBGROUPS OF FINITE GROUPS

A subgroup H of a finite group G is said to be complemented in G if there exists a subgroup K of G such that G = HK and H n X = 1. In this easel K is called a complement of H in G. In this note some results on complemented subgroups of finite groups are obtained.