2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/14500We investigate to which extent a time variation of the gravitational constant or other fundamental constants affects the best fit of the Hubble diagram of type Ia supernovae. In particular, we show that a slow increase of $G$ in the past, below experimental constraints, can reconcile the SNe Ia observations with an open zero-$Λ$ universe.7 pages, including 4 figures, revtexAstrophysicstext