演讲者：孙放
时间：2017-08-16 16:10-17:10
地点：慧园3栋 415报告厅
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.
