Hello,

I´ve got a question concerning convex balls:

Let 0<k<n and G(n,k) denote the Grassmannian of (non-oriented) k-planes in \IR^n. If P is a k-plane in G(n,k), what is the greatest radius r>0, such that the geodesic ball

B_r(P) is convex?

Thank you for helping me!

Regards,

Kevin