A NOTE ON NIELSEN EQUIVALENCE IN FINITELY GENERATED ABELIAN GROUPS

Nielsen transformations determine the automorphisms of a free group of rank n, and also of a free abelian group of rank n, and furthermore the generating n-tuples of such groups form a single Nielsen equivalence class. For an arbitrary rank n group, the generating n-tuples may fall into several Nielsen classes. Diaconis and Graham ['The graph of generating sets of an abelian group', Colloq. Math. 80 (1999), 31-38] determined the Nielsen classes for finite abelian groups. We extend their result to the case of infinite abelian groups.