Class-preserving automorphisms and the normalizer property for Blackburn groups

dc.creatorHertweck, Martin
dc.creatorJespers, Eric
dc.date2007-01-05
dc.date2008-03-07
dc.date.accessioned2026-07-07T09:25:20Z
dc.date.available2026-07-07T09:25:20Z
dc.descriptionFor a group $G$, let $U$ be the group of units of the integral group ring $\mathbb{Z}G$. The group $G$ is said to have the normalizer property if $\text{N}_U(G)=\text{Z}(U)G$. It is shown that Blackburn groups have the normalizer property. These are the groups which have non-normal finite subgroups, with the intersection of all of them being nontrivial. Groups $G$ for which class-preserving automorphisms are inner automorphisms, $\text{Out}_c(G)=1$, have the normalizer property. Recently, Herman and Li have shown that $\text{Out}_c(G)=1$ for a finite Blackburn group $G$. We show that $\text{out}_c(G)=1$ for the members $G$ of a few classes of metabelian groups, from which the Herman--Li result follows. Together with recent work of Hertweck, Iwaki, Jespers and Juriaans, our main result implies that, for an arbitrary group $G$, the group of hypercentral units of $U$ is contained in $\text{Z}(U)G$.
dc.description10 pages. Proof of Lemma 2.2 improved. Added Example 2.3
dc.identifierhttps://arxiv.org/abs/math/0701159
dc.identifierhttp://arxiv.org/abs/math/0701159
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/156371
dc.subjectGroup Theory
dc.subjectRings and Algebras
dc.subject20F28; 16S34
dc.titleClass-preserving automorphisms and the normalizer property for Blackburn groups
dc.typetext

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