There is a vast potential in using the measurement of the flavor composition of high-energy (TeV-PeV) astrophysical neutrinos to test astrophysics and fundamental physics. But there is also plenty of uncertainty in the prediction of the allowed flavor composition at Earth, due to the uncertainties in the mixing parameters, and in the measurement of flavor composition in neutrino telescopes. In other words, flavor is a powerful tool, but it needs sharpening.

In our latest paper, we show that in the next 20 years, flavor will become the sharp tool it was always meant to be, thanks to new oscillation experiments and new neutrino telescopes:

The Future of High-Energy Astrophysical Neutrino Flavor Measurements
Ningqiang Song, Shirley Weishi Li, Carlos A. Argüelles, Mauricio Bustamante, Aaron C. Vincent
https://arxiv.org/abs/2012.12893

By 2040, we will be able to use flavor composition by itself to identify the production mechanism of high-energy astrophysical neutrinos: