Author(s) :

TAEHO KIM.

Volume/Issue :

Abstract :

Type Ia supernovae (SNe Ia) serve as standardizable candles crucial for probing cosmic expansion and constraining cosmological parameters. SNe Ia have been standardized using their light-curves for nearly three decades, but more recent studies in the past 15 years have found that SN Ia brightnesses after light-curve corrections depend on their host-galaxy stellar masses. It has since become the standard to correct for this unexplained phenomenon by applying a ‘mass-step’ correction, where SNe Ia in host galaxies above a certain stellar-mass (mass-step location) are taken to be about 0.05 to 0.10 magnitudes (mag) or about 5 to 10% brighter than SNe Ia in host galaxies below the mass-step location. In this paper, three representative SN Ia surveys, the Dark Energy Survey 5 Year Supernova Analysis (DES-SN5YR), Pantheon+, and the Joint Light-curve Analysis (JLA) are analyzed and compared against each other. This work specifically focuses on the mass-step implementation in each of the surveys and how this correction impacts inferred cosmological parameters across varying redshifts.