Centralizers of gap groups
Tom 226 / 2014
Fundamenta Mathematicae 226 (2014), 101-121
MSC: Primary 57S17; Secondary 20C15.
DOI: 10.4064/fm226-2-1
Streszczenie
A finite group $G$ is called a gap group if there exists an $\mathbb {R}G$-module which has no large isotropy groups except at zero and satisfies the gap condition. The gap condition facilitates the process of equivariant surgery. Many groups are gap groups and also many groups are not. In this paper, we clarify the relation between a gap group and the structures of its centralizers. We show that a nonsolvable group which has a normal, odd prime power index proper subgroup is a gap group.