On Cohomogeneity Two Riemannian Manifolds of Non-Positive Curvature

详细

We study a cohomogeneity two Riemannian G-manifold M of non-positive curvature. Considering the acting group G, we obtain some facts about the structure of such manifolds and their orbits. Moreover in some cases, the existence of the G-invariant metrics with non-positive (or negative) curvature on M is proved.