On the topological entropy of an optical Hamiltonian flow

In this paper, we prove two formulae for the topological entropy of an -optical Hamiltonian flow induced by HC∞(M,), where is a Lagrangian distribution. In these formulae, we calculate the topological entropy as the exponential growth rate of the average of the determinant of the differential of the flow, restricted to the Lagrangian distribution or to a proper modification of it.