Remarks on chains of weakly closed subgroups

Abstract

AbstractIn this paper we generalize and unify several results proved in recent papers about the existence of normalMoreover a counterexample is given to a question in [Guo and Wei, J. Group Theory 13: 267–276, 2010] and it is proved that a finite group is 2-nilpotent if the cyclic subgroups of order less or equal than four are strongly closed.