Banana Split: Improved Cosmological Constraints with Two Light-Curve-Shape and Color Populations Using Union3.1+UNITY1.8
This research updates cosmological constraints using Type Ia supernovae by incorporating evidence for two distinct light-curve shapes and color distributions. By modeling these populations separately, the study significantly tightens cosmological constraints on dark energy parameters like $\Omega_m$, $w_0$, and $w_a$. The new model shows improved fit and reduced uncertainties compared to previous single-mode analyses.