Residually rationally solvable one-relator groups

Abstract

We show that the intersection of the rational derived series of a one-relator group is rationally perfect and is normally generated by a single element. As a corollary, we characterise precisely when a one-relator group is residually rationally solvable.

arXiv comment12 pages, v2 incorporating referee's comments. To appear in Bull. Lond. Math. Soc