SF-4: Neutrino Sector Unification from 600-Cell Geometry

Abstract: The Standard Model has no internal explanation for neutrino masses, mixing angles, or hierarchy ordering. SF-4 derives seven of the eight observable neutrino parameters at zero free parameters from a single calibration (the electron mass) plus the 600-cell substrate geometry. The cage-shell mass formula m_nu = M_0 V^2 sigma_nu, with V in {4,12,30} forced by 600-cell topology and a suppression factor sigma_nu = z^(-10) approximately 1.62e-11, matches the absolute mass scale within 2 percent, while the PMNS mixing matrix recovers tribimaximal mixing exactly at zeroth order. The paper achieves the first cross-sector closure in CPP at v4.0, jointly resolving OPEN-FP-SF-4-2 and SM-5's foundational K3-eigenmode identification problem; the delta_CP phase is deferred to the SF-2 electroweak flagship.