Geometry & Topology Seminar

Topological Symmetries of R^3

It has been shown that smooth orientation preserving actions on R^4 by finite groups need not be smoothly conjugate to orthogonal ones. Yet such group (assuming faithfulness) is always isomorphic to a subgroup of SO(4). We showed that analogous algebraic rigidity holds for topological actions on R^3,despite a similar lack of geometric rigidity.