Model independent bounds on Type Ia supernova absolute peak magnitude

TL;DR

This paper uses a model-independent, non-parametric Gaussian process approach to constrain the peak absolute magnitude of Type Ia supernovae, achieving sub-percent level precision and consistency across multiple datasets.

Contribution

It introduces a Gaussian process regression method to derive bounds on supernova brightness without relying on specific cosmological models.

Findings

Peak absolute magnitude constrained to about -19.4 with sub-percent precision.

Inclusion of BAO and CMB data tightens the bounds significantly.

Results are consistent across different data combinations.

Abstract

We put constraints on the peak absolute magnitude, $M_B$ of type Ia supernova using the Pantheon sample for type Ia supernova observations and the cosmic chronometers data for the Hubble parameter by a model independent and non-parametric approach. Our analysis is based on the Gaussian process regression. We find percent level bounds on the peak absolute magnitude given as $M_B=-19.384\pm0.052$. For completeness and to check the consistency of the results, we also include the Baryon acoustic oscillation data and the prior of the comoving sound horizon from Planck 2018 cosmic microwave background observations. The inclusion of these two data gives tighter constraints on $M_B$ at the sub-percent level. We obtain constraints on $M_B$ from the combination of pantheon compilation of type Ia supernova observations and baryon acoustic oscillation observations given as $M_B=-19.396\pm0.016$. When adding the cosmic chronometer observations with these observations, we find $M_B=-19.395\pm0.015$. The mean values of peak absolute magnitude from all these data are consistent with each other and the values are approximately equal to $-19.4$.