Velychko T. Studying the structure of groups saturated permutable subgroups

The systems of subgroups, which in a sense are the antipodes of normal subgroups and generalized normal subgroups, have great influence on the structure of the group. Particular attention in this thesis is given to permutable and pronormal subgroups. In this thesis we describe locally finite groups whose finitely generated subgroups are either permutable or pronormal. We obtain a description of certain classes of infinite non-periodic groups whose finitely generated subgroups are either permutable or pronormal. Such a generalization as weakly pronormal subgroups was considered for the pronormal subgroups. We obtain a description of certain classes of infinite non-periodic groups whose finitely generated subgroups are either permutable or weakly pronormal. Almost normal and contranormal subgroups have been considered in this thesis. We study the groups whose subgroups are either almost normal or contranormal. Moreover, we also provide a description of locally soluble group with this property. We obtain a full description of locally soluble group, whose subgroups are almost normal or contranormal.