2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/3119At the level of the Planck scale, the spacetime metric has to be considered a quantum variable. Conformal quantum fluctuations of the metric tensor are studied here. They lead to an extra term in the Einstein equations which can be identified with a cosmological constant. Quantum fluctuations may therefore contribute to an accelerated expansion of the universe, in accordance with newer observational data.5 pages, LaTeX, 1 figure (EPS)Astrophysicstext