Neutrino self-interaction with a larger “Fermi constant” is often resorted for understanding puzzles of our universe. I will first discuss how novel neutrino self-interactions can save the sterile neutrino dark matter produced through early universe oscillation mechanism, which is otherwise ruled out by cosmological observations. The explanation requires the existence of a light scalar boson that couples exclusively to neutrinos and sets a well-motivated target for experimental probes. In the second part of talk, I will review existing constraints on the neutrinophilic scalar, and point out pathways for testing the model in upcoming experiments.
https://indico.ijs.si/event/2582/