We introduce and study a new discrete basis of gravity constraints by
making use of harmonic expansion for closed cosmological models, The f
ull set of constraints is split into area-preserving spatial diffeomor
phisms, forming closed subalgebra, and Virasoro-like generators. Opera
tional Hamiltonian BFV-BRST quantization is performed in the framework
of perturbative expansion in the dimensionless parameter, which is a
positive power of the ratio of Planckian volume to the volume of the U
niverse. For the (N + 1)-dimensional generalization of stationary clos
ed Bianchi-I cosmology the nilpotency condition for the BRST operator
is examined in the first quantum approximation. It turns out that a ce
rtain relationship between the dimensionality of the space and the spe
ctrum of matter fields emerges from the requirement of quantum consist
ency of the model. (C) 1997 Elsevier Science B.V.