A note on uncountable groups with modular subgroup lattice

Abstract

The aim of this paper is to investigate the behaviour of uncountable groups of cardinality \({\aleph}\) in which all proper subgroups of cardinality \({\aleph}\) have modular subgroup lattice. It is proved here that the lattice of subgroups of such a group G is modular, provided that G has no infinite simple homomorphic images of cardinality \({\aleph}\). A corresponding result for groups whose proper subgroups of large cardinality are quasihamiltonian is also proved.