%0 Journal Article %T Incomplete Dirac reduction of constrained Hamiltonian systems %A C. Chandre %J Physics %D 2014 %I arXiv %X First-class constraints constitute a potential obstacle to the computation of a Poisson bracket in Dirac's theory of constrained Hamiltonian systems. Using the pseudoinverse instead of the inverse of the matrix defined by the Poisson brackets between the constraints, we show that a Dirac-Poisson bracket can be constructed, even if it corresponds to an incomplete reduction of the original Hamiltonian system. The uniqueness of Dirac brackets is discussed. %U http://arxiv.org/abs/1412.4922v1