For any finite subgroup of , we construct a contractible –manifold , with an effective –action on its boundary, that can be embedded in a closed –manifold so that cutting out and regluing using distinct elements of will always yield distinct smooth –manifolds.
"Equivariant corks." Algebr. Geom. Topol. 17 (3) 1771 - 1783, 2017. https://doi.org/10.2140/agt.2017.17.1771