Speaker
Description
In this talk, I will discuss a novel origin for the disparity between quark and lepton flavour mixing based on the refractive nature of neutrino masses. We postulate that the fundamental mixing in both the quark and lepton sectors is CKM-like, together with tiny vacuum neutrino masses, while the observed PMNS mixing matrix emerges dynamically from coherent forward scattering of neutrinos on an ultralight dark matter background. The resulting in-medium Hamiltonian rotates CKM mixing angles into large effective lepton mixings, naturally realising quark--lepton complementarity without invoking new flavour symmetries. This framework links neutrino mass generation, flavour mixing, and dark matter, and predicts environment-dependent neutrino oscillation effects testable in current and future experiments.