We prove the existence of a spectral resolution of the Wheeler-DeWitt
equation when the matter field is provided by a Yang-Mills field, with or
without mass term, if the spatial geometry of the underlying spacetime is
homothetic to R[3]. The energy levels of the resulting quantum model, i.e.,
the eigenvalues of the corresponding self-adjoint Hamiltonian with a pure point
spectrum, are strictly positive.Comment: 9 pages, v3: minor corrections to bring it in line with the published
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