Wigner's Formulation of Noncommutative Quantum Mechanics
  When we have noncommutativity among coordinates (or conjugate momenta), we consider Wigner's formulation of quantum mechanics, including a new derivation of path integral formula. We also propose the Moyal star product based on the Dirac bracket in constrained systems. 
Akira Kokado, Takashi Okamura, Takesi Saito