Class-preserving automorphisms of descending HNN extensions of abelian groups
Wei Zhou, Goansu Kim · Journal of Algebra and Its Applications · 2024
We consider descending HNN extensions [Formula: see text], where [Formula: see text] is abelian. We show that class-preserving automorphisms of descending HNN extensions are all inner if [Formula: see text] is abelian and [Formula: see text]. It follows that outer automorphism groups of such conjugacy separable descending HNN extensions are residually finite.