Pestov's Identity on frame bundles and applications
  In this article we lift Pestov's Identity on the tangent bundle of a Riemannian manifold $M$ to the bundle of $k$-tuples of tangent vectors. We also derive an integrated version and a restriction to the frame bundle $P^kM$ of $k$-frames. Finally, we discuss a dynamical application for the parallel transport on $\mathcal{G}_{or}^k(M)$, the Grassmannian of oriented $k$-planes of $M$. 
Michela Egidi
math.DG