We construct the Green bundles for an energy level without conjugate points
of a convex Hamiltonian. In this case we give a formula for the metric ent
ropy of the Liouville measure and prove that the exponential map is a local
diffeomorphism. We prove that the Hamiltonian flow is Anosov if and only i
f the Green bundles are transversal. Using the Clebsch transformation of th
e index form we prove that if the unique minimizing measure of a generic La
grangian is supported on a periodic orbit, then it is a hyperbolic periodic
orbit.
We also show some examples of differences with the behaviour of a geodesic
flow without conjugate points, namely: (non-contact) flows and periodic orb
its without invariant transversal bundles, segments without conjugate point
s but with crossing solutions and non-surjective exponential maps.