Diffeomorphism invariant measure for finite-dimensional geometries Original Research Article

We consider families of geometries of D-dimensional space, described by a finite number of parameters. Starting from the DeWitt metric we extract a uniquer integration measure which turns out to be a geometric invariant, i.e. indepeendent of the gauge fixed metric used for describing the geometries. The measure is also invariant in form under an arbitrary change of parameters describing the geometries. We prove the existence of geometries for which there are no related gauge fixing surfaces orthogonal to the gauge fibers. The additional functional integration on the conformal factor makes the measure independent of the free parameter intervening in the DeWitt metric. The determinants appearing in the measure are mathematically well defined even though technically difficult to compute.