Eigenvalue equation for momentum dispersion operator and properties of phase space wavefunctions

This paper is a continuation of our previous works concerning coordinate, momentum, dispersion operators and phase space representation of quantum mechanics. It deals with the properties of momentum dispersion operator, its representations, eigenvalue equation and its relations with the wavefunctions in the phase space representation. After recalling some results from our previous works, we perform a study concerning the phase space wavefunctions and consider some example of them. Then we establish the eigenvalue equation for the differential operator corresponding to the momentum dispersion operator in the phase space representation. It is shown in particular that any wavefunction in phase space representation is solution of this equation.