Constraining electron number density in the Sun via Earth-based neutrino flavor data

Neutrino flavor transformation offers a window into the physics of various astrophysical environments, including our Sun and the more exotic environs of core-collapse supernovae and binary neutron-star mergers. Here, we apply an inference framework - specifically: statistical data assimilation (SDA) - to neutrino flavor evolution in the Sun. We take a model for solar neutrino flavor evolution, together with Earth-based neutrino measurements, to infer solar properties. Specifically, we ask what signature of the radially-varying solar electron number density nₑ(r) is contained within these Earth-based measurements. Currently, the best estimates of nₑ(r) come from the standard solar model. We seek to ascertain, through novel application of the SDA method, whether estimates of the same from neutrino data can serve as independent constraints.