Lower limits on the Hubble constant from models of type Ia supernovae

Abstract

By coupling observations of type Ia supernovae with results obtained from the best available numerical mod- els we constrain the Hubble constant, independently of any external calibrators. We find an absolute lower limit of H0 > 50 km s −1 Mpc −1 . In addition, we construct a Hubble diagram with UVOIR light curves of 12 type Ia supernovae located in the Hubble flow, and when adopting the most likely values (obtained from 1-D and 3-D deflagration simulations) of the amount of 56 Ni produced in a typical event, we find values of H0 ≥ 66 ± 8a nd≥78 ± 9k m s −1 Mpc −1 , respectively. Our result may be difficult to reconcile with recent discussions in the literature as it seems that an Einstein-de Sitter universe requires H0 � 46 km s −1 Mpc −1 in order to fit the temperature power spectrum of the cosmic microwave background and maintain the age constraints of the oldest stars.