Abstract
We further investigate relations between dispersive effects (like the Morawetz inequality) for various classical equations: Schrödinger, Dirac, and wave equations. After Wigner transform, these dispersive estimates are reduced to moment lemmas for kinetic equations. They yield new results for the Schrödinger (valid up to the semiclassical limit), wave, and Dirac equations; radial pseudo-differential operators; and also kinetic equations.