On the relationships between the factors of upper and lower central series in groups and other algebraic structures

Abstract

We discuss some new recent development of the well known classical R. Baer and B. Neumann theorems. More precisely, we want to show the thematic which evolved from the mentioned classical results describing the relations between the central factor-group and the derived subgroup in an in nite group. We track these topics not only in groups, but also in some other algebraic structures