On σ-Embedded and σ-n-Embedded Subgroups of Finite Groups

Siberian Mathematical Journal - Let G be a finite group, and let σ = {σi | i ∈ I} be a partition of the set of all primes ℙ and σ(G) = {σi | σi ∩...     

Subgroups of Finite Symmetric Groups

Recent results about primitive permutation groups are surveyed.     

On F-Abnormal Maximal Subgroups of Finite Groups

For any saturated formation F of finite groups containing all supersolvable groups, the groups in F are characterized by F-abnormal maximal subgroups.     

On σ-semipermutable Subgroups of Finite Groups

Let σ = {σ_i|i ∈ I } be some partition of the set of all primes P, G a finite group andσ(G) = {σ_i |σ_i ∩π(G) = ?}. A set H of subgroups of G is said to be a complete Hall σ-set of G if every member = 1 of H is a Hall σ_i-subgroup of G for some σ_i ∈σ and H contains exactly one Hallσ_i-subgroup of G for every σ_i ∈σ(G). A subgroup H of G is said to be: σ-semipermutable in G with respect to H if H H_i~x= H_i~xH for all x ∈ G and all H_i ∈ H such that(|H|, |H_i|) = 1; σ-semipermutable in G if H is σ-semipermutable in G with respect to some complete Hall σ-set of G. We study the structure of G being based on the assumption that some subgroups of G are σ-semipermutable in G.     

Finite Groups with Only s-quasinormal and Abnormal Subgroups

The concept of an abnormal subgroup of a group G is, in a sense, opposite of thatof a normal subgroup of G. In [J. Algebra, 28(1974), 15-19) Fattahi studied those finitegroups in which each subgroup is either normal or abnormal and characterized all suchgroups. In this paper, as a generalization of Fattahi's result, we study more general groups,i. e., groups with only s-quasinormal and abnormal subgroups and characterize all suchgroups. Morever, some interesting conclusions are also obtained.     

On ℳ p -Supplemented Subgroups of Finite Groups

A subgroup H of G is called ? _p -supplemented in G if there exists a subgroup B of G such that G = HB and TB < G for every maximal subgroup T of H with |H: T| =p ^α. In this paper, we investigate the influence of ? _p -supplemented subgroup and some conditions for p-nilpotency and p-supersolvability of finite groups are obtained.     

On Weakly ℋ-embedded Subgroups of Finite Groups

Let G be a finite group and H a subgroup of G. We say that H is an ?-subgroup in G if N_G(H) ∩ H^g ≤ H for all g ∈ G; H is called weakly ?-subgroup in G if G has a normal subgroup K such that G = HK and H ∩ K is an ?-subgroup in G. We say that H is weakly ? -embedded in G if G has a normal subgroup K such that H^G = HK and H ∩ K is an ?-subgroup in G. In this paper, we investigate the structure of the finite group G under the assumption that some subgroups of prime power order are weakly ?-embedded in G. Our results improve and generalize several recent results in the literature.     

On Φ-τ-Supplement Subgroups of Finite Groups

Let τ be a subgroup functor and H a p-subgroup of a finite group G. Let G= G/H_G and H= H/H_G. We say that H is Φ-τ-supplement in G if G has a subnormal subgroup T and a τ-subgroup S contained in H such that G=H T and H∩T≤SΦ(H). In this paper,some new characterizations of hypercyclically embedability and p-nilpotency of a finite group are obtained based on the assumption that some primary subgroups are Φ-τ-supplement in G.     

On Π-Permutable Subgroups in Finite Groups

Ukrainian Mathematical Journal - Let σ = {σi | i ∈ I} be a partition of the set of all primes ? and let Π be a nonempty subset of the set σ. A set ? of...     

On Subgroups and Quotient Groups of L-fuzzy Topological Groups

In paper [1], it gave the concept and basic properties of L-fuzzy topological groups. This paper will enter the concept of quotient groups of L-fuzzy topological groups and will prove some properties of subgroups and quotient groups. The persent work is the continuation of [1] and hence all the conventions in [1] still hold good in the present paper.     

Finite Groups with only S-seminormal or Selfnormal Subgroups

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On Finite Groups with Some Semi Cover-Avoiding Subgroups

A subgroup H of a finite group G is said to have the semi-cover-avoiding property in G if there is a chief series of G such that H covers or avoids every chief factor of the series. In this paper, some new results are obtained based on the assumption that some subgroups have the semi-cover-avoiding property in the group.     

Classification of Finite Groups Whose Cyclic Subgroups of Composite Order are Subnormal

Recently,alongseriesofpapersdealtswithclassificationsoffinitegroupsundersomespe-cialassumptions.Herewementiononlyfourofthem.In[4],M.Deaconescuclassifiedgroupsallofwhosecyclicsubgroupshaveprimeorder,J.Buckleyin[1]describedthestructureofgroupsinwhichallsubgroupshaveatmosttwoconjugatesandin[2],R.Brandlcharacterizedgroupsallofwhosenon-normalsubgroupsaerconjugate.Asanotherexample,see[8].Inthispaperweareconcernedwithgroupsallofwhosecyclicsubgroupsofcompositeor-deraresubnormalandweshallalsoclassif…     

Finite Groups With Small Automizers for Their Nonabelian Subgroups

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Finite Groups Whose Second Maximal Subgroups are ℋ-QC-Subgroups

A group G is called an “?-QC-group” if for any element x of order 2 or 4 of G, ?x? ?y? = ?y? ?x? for all y in G. In this article, we investigate the structure of the groups G of the title. Suppose that G is non-2-closed and non-2-nilpotent, then it turns out that such a group is either S ₄ or a uniquely determined group of order 48 or A ₅ or SL(2,5). The corresponding problem for G 2-closed or 2-nilpotent is open but very difficult.