Action-angle variables for geodesic motions in Sasaki-Einstein spaces   $Y^{p,q}$
  We use the action-angle variables to describe the geodesic motions in the $5$-dimensional Sasaki-Einstein spaces $Y^{p,q}$. This formulation allows us to study thoroughly the complete integrability of the system. We find that the Hamiltonian involves a reduced number of action variables. Therefore one of the fundamental frequency is zero indicating a chaotic behavior when the system is perturbed. 
Mihai Visinescu
hep-th