American Journal of Physics
The symplectic egg in classical and quantum mechanics
Maurice A. de Gosson
Abstract
We begin by giving correct expressions for the short-time action; following the work of one of us and Makri-Miller.We use these estimates to derive a correct expression modulo ∆t 2 for the quantum propagator and we show that the quantum potential is negligible modulo ∆t 2 for a point source.We finally prove that this implies that the quantum motion is classical for very short times.