turkmath.org

Studying symmetries of topological spaces is a classical topic in algebraic topology. Finite groups which can act freely on a sphere are completely classified but there are many unanswered questions related to free actions on products of spheres or about actions on spheres with nontrivial isotropy subgroups. In this talk I will give a survey of well-known results in this area and present some new results from our joint work with Ian Hambleton related to rank two finite group actions on homotopy spheres with rank one isotropy.