Ia-Automorphisms and Permutational Wreath Products
Let be an uncountable universal locally finite group. We study subgroups such that for every , .
Let be a field, be a vector space over , be the group of all automorphisms of the vector space . A subspace is called almost -invariant, if is finite. In the current article, we begin the study of those subgroups of for which every subspace of is almost -invariant. More precisely, we consider the case when is a periodic group. We prove that in this case includes a -invariant subspace of finite codimension whose subspaces are -invariant.
Let F be a field, A be a vector space over F, GL(F, A) be the group of all automorphisms of the vector space A. A subspace B of A is called nearly G-invariant, if dimF(BFG/B) is finite. A subspace B is called almost G-invariant, if dim F(B/Core G(B)) is finite. In the current article, we study linear groups G such that every subspace of A is either nearly G-invariant or almost G-invariant in the case when G is a soluble p-group where p = char F.
In classifying certain infinite groups under minimal conditions it is needed to find non-simplicity criteria for the groups under consideration. We obtain some of such criteria as a consequence of the main result of the paper and the classification of finite simple groups.
In this paper we deal with the class of groups for which whenever we choose two infinite subsets , there exist two elements , such that . We prove that an infinite finitely generated soluble group in the class is in the class of -Engel groups. Furthermore, with , we show that if is infinite locally soluble or hyperabelian group then .
Let be a compact connected oriented surface with one boundary component, and let be the fundamental group of . The Johnson filtration is a decreasing sequence of subgroups of the Torelli group of , whose -th term consists of the self-homeomorphisms of that act trivially at the level of the -th nilpotent quotient of . Morita defined a homomorphism from the -th term of the Johnson filtration to the third homology group of the -th nilpotent quotient of . In this paper, we replace groups...