Infinitely many not locally soluble $S{I}^{\ast }$-groups

Abstract

The class of those (torsion-free) $S{I}^{\ast }$-groups which are not locally soluble, has the cardinality of the continuum. Moreover, these groups are not only pairwise non-isomorphic, but also they generate pairwise different varieties of groups. Thus, the set of varieties generated by not locally soluble $S{I}^{\ast }$-groups is of the same cardinality as the set of all varieties of groups. It is possible to localize a variety of groups which contains all groups and varieties constructed. The examples constructed here continue the well known example of a not locally soluble $S{I}^{\ast }$-group built by Hall and by Kovács and Neumann.

arXiv comment16 pages