Type: Article
Publication Date: 1987-04-01
Citations: 33
DOI: https://doi.org/10.2307/2000369
If $G$ is a compact Lie group and $M$ a Riemannian $G$-manifold with principal orbits of codimension $k$ then a section or canonical form for $M$ is a closed, smooth $k$-dimensional submanifold of $M$ which meets all orbits of $M$ orthogonally. We discuss some of the remarkable properties of $G$-manifolds that admit sections, develop methods for constructing sections, and consider several applications.