Inference of bipolar neutrino flavor oscillations near a core-collapse supernova, based on multiple measurements at Earth

Understand

Neutrinos in compact-object environments, such as core-collapse supernovae, can experience various kinds of collective effects in flavor space, engendered by neutrino-neutrino interactions.

• These include "bipolar" collective oscillations, which are exhibited by neutrino ensembles where different flavors dominate at different energies.
• Considering the importance of neutrinos in the dynamics and nucleosynthesis in these environments, it is desirable to ascertain whether an Earth-based detection could contain signatures of bipolar oscillations that occurred within a supernova envelope.
• To that end, we continue examining a cost-function formulation of statistical data assimilation (SDA) to infer solutions to a small-scale model of neutrino flavor transformation.