CIGaRS I: Combined simulation-based inference from type Ia supernovae and host photometry

ArXi:2508.15899v2 Announce Type: replace-cross Using type Ia supernovae as cosmological probes requires empirical corrections that are correlated with their host environment. Here we present a unified Bayesian hierarchical model designed to infer, from purely photometric observations, the intrinsic dependence of the brightness of type Ia supernovae on progenitor properties (metallicity and age), the delay-time distribution that governs their rate as a function of age, and cosmology, as well as the redshifts of all hosts.