Paranilpotency in uncountable groups

Abstract

The aim of this paper is to provide a contribution to the theory of uncountable groups and to that of paranilpotent groups. Extending the structural results in Franciosi and de Giovanni (Ricerche Mat 40:321–333, 1991) and de Giovanni et al. (Comm Algebra 49:3020–3033, 2021), we prove that locally soluble minimal non-paranilpotent groups, i.e. non-paranilpotent groups whose proper subgroups are paranilpotent, are soluble. It is also shown that the class of paranilpotent groups is countably recognizable and, as an application of these results, that a soluble uncountable group whose proper uncountable subgroups are paranilpotent is itself paranilpotent.