Some Observations on projective Stiefel Manifolds

Abstract: We compute the upper characteristic rank of the projective Stiefel manifolds over $\mathbb R, \mathbb C$ and $\mathbb H$ and of the flip Stiefel manifolds. We provide bounds for the cup lengths of these spaces. We also provide necessary conditions for existence of $S^3$-map between quaternionic Stiefel manifolds using Fadell-Husseini index.