Phase space observables and isotypic spaces
  We give necessary and sufficient conditions for the set of Neumark projections of a countable set of phase space observable to constitute a resolution of the identity, and we give a criteria for a phase space observable to be informationally complete. The results will be applied to the phase space observables arising from an irreducible representation of the Heisenberg group. 
G. Cassinelli, E. De Vito, A. Levrero, P. Lahti