2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/95619We regard the Wheeler-De Witt equation as a Sturm-Liouville problem with the cosmological constant considered as the associated eigenvalue. The used method to study such a problem is a variational approach with Gaussian trial wave functionals. We approximate the equation to one loop in a Schwarzschild background. A zeta function regularization is involved to handle with divergences. The regularization is closely related to the subtraction procedure appearing in the computation of Casimir energy in a curved background. A renormalization procedure is introduced to remove the infinities together with a renormalization group equation.9 pages, RevTeX 4, to appear in TSPU VestnikGeneral Relativity and Quantum CosmologyHigh Energy Physics - Theorytext