On D. I. Moldavanskii's Question About p-Separable Subgroups of a Free Group

Siberian Mathematical Journal - We prove that every free nonabelian group has a finitely generated isolated subgroup not separable in the class of nilpotent groups. This enables us to give a...     

On Groups with Finite Involution and Locally Finite 2-Isolated Subgroup of Even Period

A proper subgroup H of a group G is said to be strongly isolated if it contains the centralizer of any nonidentity element of H and 2-isolated if the conditions >C _G(g) H 1 and 2(C_G(g)) imply that C_G(g)H. An involution i in a group G is said to be finite if |ii ^g| < (for any g G). In the paper we study a group G with finite involution i and with a 2-isolated locally finite subgroup H containing an involution. It is proved that at least one of the following assertions holds:1) all 2-elements of the group G belong to H;2) (G,H) is a Frobenius pair, H coincides with the centralizer of the only involution in H, and all involutions in G are conjugate;3) G=FFC_G(i) is a locally finite Frobenius group with Abelian kernel F;4) H=V D is a Frobenius group with locally cyclic noninvariant factor D and a strongly isolated kernel V, U=O₂(V) is a Sylow 2-subgroup of the group G, and G is a Z-group of permutations of the set =U ^g g G.     

On a Question of M. Conder

It is proved that SL ₃() cannot be generated by two elements of orders 2 and 3.     

Constructing some designs invariant under PSL2(q), q even

In this paper, we use Key-Moori methods 1 and 2 to construct some designs from the maximal subgroups and conjugacy classes of the group PSL₂(q), where q is a power of 2.     

FINITE GROUPS WITH SOME PRIMARY SUBGROUPS F-s-SUPPLEMENTED

Let F be a class of groups. A subgroup H of a group G is called F-s-supplemented in G if there exists a subgroup K of G such that G = HK and K|K ∩ H_G belongs to F. We obtain some results about the F-s-supplemented subgroups and use them to determine the structure of some groups. In particular, some new criteria of p-nilpotency, solubility, supersolubility of a group are obtained.     

((∈),(∈)V(q)(λ,μ))-模糊正规子群的若干性质

本文研究了((∈),(∈)V(q)(λ,μ))-模糊正规子群的一些新的性质.利用反扩张原理获得了它的满同态像与同态原像的相关结果,丰富了文献[1]中有关((∈),(∈)V(q)(λ,μ))-模糊正规子群的研究结果.     

Connected components of compact matrix quantum groups and finiteness conditions

We introduce the notion of identity component of a compact quantum group and that of total disconnectedness. As a drawback of the generalized Burnside problem, we note that totally disconnected compact matrix quantum groups may fail to be profinite. We consider the problem of constructing the identity component by introducing canonical approximating transfinite sequences of subgroups. These sequences have lengths ≤1 in the classical case but can be countably infinite for duals of discrete groups. We give examples of free product quantum groups where the identity component is not normal and the associated sequence has length 1.     

l-群的凸-子群格的极小条件

设G是l-群,C(G)是G的凸l-子群格.称C(G)满足极小条件,如果C(G)中每个元均包台一个原子元.本文将C(G)的链条件(见文[1])推广到极小条件,主要结果是:C(G)满足极小条件且C(G)中每个原子元均是G的基数直和项当且仅当∑λ∈ΛRλ(∩)G(∩)Пλ∈ΛRλ(其中每个Rλ≌实数加群R的某个子群).     

On the Combinatorics of Projective Mappings

We consider composition sets of one-dimensional projective mappings and prove that small composition sets are closely related to Abelian subgroups.