Cyclic Group Actions on Contractible 4-Manifolds
arXiv:1412.5877 · doi:10.2140/gt.2016.20.1127
Abstract
There are known infinite families of Brieskorn homology 3-spheres which can be realized as boundaries of smooth contractible 4-manifolds. In this paper we show that free periodic actions on these Brieskorn spheres do not extend smoothly over a contractible 4-manifold. We give a new infinite family of examples in which the actions extend locally linearly but not smoothly.
20 pages: final version, to appear in Geometry & Topology