Concordance of $\mathbb{Z}_p\times\mathbb{Z}_p$ actions on $S^4$

Abstract

We prove that locally linear, orientation-preserving actions of $G={\mathbb{Z}}_p\times {\mathbb{Z}}_p$ on $S^4$ are concordant if and only if a ${\mathbb{Z}}_2$–valued surgery obstruction vanishes, and discuss constructions and examples.