ABSTRACT
We already introduced polar actions on Riemannian manifolds in Section 2.3. The main result in Section 2.3 was Dadok’s Theorem, which states that every polar representation on Rn is orbit equivalent to an s-representation. In this and the next chapter we discuss polar actions on semisimple Riemannian symmetric spaces. As one might expect, there are major differences between the compact and the noncompact case. For the compact case, the theory was developed to a large extent by Kollross and for the noncompact case by Berndt and Tamaru. We deal with the compact case in this chapter and with the noncompact case in the next chapter.
