Prof.
Maria Giovanna
Dainotti
National Astronomical Observatory of Japan, Tokyo
Type Ia Supernovae (SNe Ia) are considered the most reliable standard candles and they have played an invaluable role in cosmology since the discovery of the Universe's accelerated expansion. In this era of precision cosmology, the community strives to find new ways to reduce uncertainties on cosmological parameters. To this end, we start our investigation even from the likelihood assumption of Gaussianity, implicitly used in this domain. Indeed, the usual practice involves constraining parameters through a Gaussian distance moduli likelihood. This method relies on the implicit assumption that the difference between the distance moduli measured and the ones expected from the cosmological model is Gaussianly distributed. We find that this requirement is not fulfilled and the actual underlying distributions are a logistic and a Student's t distribution for the Pantheon and Pantheon + SNe Ia data, respectively. When we apply these new likelihoods fitting a flat ΛCDM model, we significantly reduce the uncertainties on the matter density ΩM and the Hubble constant H0 of ∼ 40%. As a result, the Hubble tension is increased at > 5 σ level. This boosts the SNe Ia power in constraining cosmological parameters, thus representing a huge step forward to shed light on the current debated tensions in cosmology.
This analysis has its important implication on the use of the GRBs, Quasars and BAO and results show a decrease in terms of cosmological parameters when also these probes are added.
We here use the Dainotti 3D relation, the fundamental plane relationship in X-rays and optical, where the first with the use of the platinum sample is the tightest GRB correlation in the literature and it has been applied for the first time with the correction for evolution.
This is a hybrid event:
Room D, the Institute of Physics PAS, Al. Lotników 32/46
Online: Zoom Link, (Passcode: 134595, Meeting ID: 823 8038 0442)
