2026-04-14T03:40:51Zhttps://recercat.cat/oai/request

oai:recercat.cat:2117/192332026-01-30T08:40:54Zcom_2072_1033col_2072_452950

00925njm 22002777a 4500 dc Gaztañaga, E. author García-Berro Montilla, Enrique author Isern Vilaboy, Jordi author Bravo Guil, Eduardo author Domínguez, Inmaculada author 2002-01 Recent high-redshift type-Ia supernovae results can be used to set new bounds on a possible variation of the gravitational constant G. If the local value of G at the space-time location of distant supernovae is different, it would change both the kinetic energy release and the amount of 56Ni synthesized in the supernova outburst. Both effects are related to a change in the Chandrasekhar mass MCh∝G-3/2. In addition, the integrated variation of G with time would also affect the cosmic evolution and therefore the luminosity distance relation. We show that the later effect in the magnitudes of type-Ia supernovae is typically several times smaller than the change produced by the corresponding variation of the Chandrasekhar mass. We investigate in a consistent way how a varying G could modify the Hubble diagram of type-Ia supernovae and how these results can be used to set upper bounds to a hypothetical variation of G. We find G/G0≲1.1 and Ġ/G≲10-11yr-1 at redshifts z≃0.5. These new bounds extend the currently available constraints on the evolution of G all the way from solar and stellar distances to typical scales of Gpc/Gyr, i.e., by more than 15 orders of magnitude in time and distance. Peer Reviewed Postprint (published version) Àrees temàtiques de la UPC::Física::Astronomia i astrofísica Supernovae Supernoves Bounds on the possible evolution of the gravitational constant from cosmological type-Ia supernovae