Can the neutrino mass be a function of time? In this talk, I will present a consistent scenario of time-varying neutrino masses, and discuss its impact on cosmology, beta decay, and neutrino oscillation experiments. Such time-varying masses are assumed to be generated by the coupling between a neutrino and an ultralight scalar dark matter candidate. I will discuss how such a model fares in the light of various cosmological bounds, such as those coming from Big Bang Nucleosynthesis, the cosmic microwave background, as well as large-scale structures. This scenario can be further constrained using neutrino oscillation experiments, beta-decay experiments like KATRIN, as well as reactor and gallium experiments. Finally, I will also touch upon some recent ideas of whether the neutrino mass can be entirely generated by neutrino-dark matter interactions.
