  Reduction to physical degrees of freedom before quantization leads to
predictions for one-loop amplitudes in quantum cosmology in the presence of
boundaries which disagree with the results obtained from Faddeev-Popov theory
and boundary-counterterms technique. However, the mode-by-mode analysis of
eigenvalue equations for gauge modes and ghost fields remains a very difficult
problem. Hence the equivalence or inequivalence of various quantization and
regularization techniques cannot be easily proved.
