Ao. Barvinsky, REDUCTION METHODS FOR FUNCTIONAL DETERMINANTS IN QUANTUM-GRAVITY AND COSMOLOGY, Physical review. D. Particles and fields, 50(8), 1994, pp. 5115-5124
The reduction algorithms for functional determinants of differential o
perators on spacetime manifolds of different topological types are pre
sented, which were recently used for the calculation of the no-boundar
y wave function and the partition function of tunneling geometries in
quantum gravity and cosmology.