Sterile Neutrinos in Astrophysical Neutrino Flavor
T. Katori, Shivesh Mandalia, Kareem Ramadan Farrag, Jordi Salvadó, Khandelwal Rishabh, C. Argüelles
Abstract
Current global constraints in neutrino mixing parameters translate to lax PMNS unitarity relations. In this work, we explore the lack of non-unitarity in the neutrino mixing matrix via the astrophysical neutrino flavor content in both standard paradigms, as well as those involving sterile neutrinos. Astrophysical neutrino flavour composition is a sensitive tool to probe both non-unitarity and the presence of sterile neutrinos over many mass scales, and is a core focus for future high-energy neutrino telescopes. We develop new techniques, including the neutrino flavor tetrahedron, to explore the effects of non-unitary mixing, as well as the significant impact sterile neutrinos have on astrophysical neutrino composition.