Complete Hamiltonian description of wave-like features in classical and quantum physics
The analysis of the Helmholtz equation is shown to lead to an exact Hamiltonian system of equations describing in terms of ray trajectories a very wide family of wave-like phenomena (including diffraction and interference) going much beyond the limits of the ordinary geometrical optics approximation, which is contained as a simple limiting case. Due to the fact that the time independent Schroedinger equation is itself a Helmoltz-like equation, the same mathematical solutions holding for a classical optical beam turn out to apply to a quantum particle beam, leading to a complete system of Hamiltonian equations which provide a set of particle trajectories and motion laws containing as a limiting case the ones encountered in classical Mechanics.