Talk:Moyal product
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[edit] moyal product implies a polarization?
So I don't really know anything about the Moyal product, but I do know this: given a polarization on a symplectic manifold, there is a privileged set of functions (classical observables) which give rise to quantum observables for which the correspondence principle holds, {f,g} = i[F,G] where on the left is denoted the Poisson bracket of functions and on the right is denoted the commutator of operators on Hilbert space, with the correspondence given by 
. These functions are fixed by the polarization condition [f,P]=P, where P is a polarization. Seems to me that the Moyal product for such polarizable observables should vanish after the second order term, and I guess this expectation is born out by some theorem that I only vaguely remember that polarizable observables are locally of the form of functions which are linear in the momentum (using the vertical polarization of the cotangent bundle). Seems the second order derivatives in the higher order terms will kill all the terms for such functions.
Thus the Moyal product ought to determine a set of polarizable functions, and it should be possible to recover the polarization from it. I wonder if I've got it right? My next question would be whether the Moyal product and the polarization are equivalent (that is, whether the polarization determines a Moyal product). I expect not. -lethe talk + 05:28, 20 April 2006 (UTC)
