Notes on phase space quantization
  We consider questions related to a quantization scheme in which a classical variable f:\Omega\to R on a phase space \Omega is associated with a semispectral measure E^f, such that the moment operators of E^f are required to be of the form \Gamma(f^k), with \Gamma a suitable mapping from the set of classical variables to the set of (not necessarily bounded) operators in some Hilbert space. In particular, we investigate the situation where the map \Gamma is implemented by the operator integral with respect to some fixed positive operator measure. The phase space \Omega is first taken to be an abstract measurable space, then a locally compact unimodular group, and finally R^2, where we determine explicitly the relevant operators \Gamma(f^k) for certain variables f, in the case where the quantization map \Gamma is implemented by a translation covariant positive operator measure. In addition, we consider the question under what conditions a positive operator measure is projection valued. 
J. Kiukas, P. Lahti, K. Ylinen