Paper 73: Triadic Modulation from SU(2) Selection Rules in the Holosphere Lattice

We develop a remodeled explanation for the structure of the cosmic microwave background power spectrum based on triadic selection rules in an SU2 lattice. The key idea is that the sky we observe is shaped by present-day angular coherence rather than a frozen last scattering surface. We derive a multi-harmonic modulation envelope from quaternionic probability on the three-sphere, triadic closure, and a coherence threshold set by percolation in the lattice. In this picture bright nodes arise from constructive interference while dark nodes arise from destructive interference, with a geometric cap on the fraction of channels that can remain bright near decoherence. The amplitude of higher harmonics follows a universal damping law that depends only on the coherence healing rate and not on cosmological curve fitting. The framework yields concrete and testable predictions. It fixes the spacing of troughs in the spectrum, sets their depth scaling with harmonic order, and forecasts continued oscillatory suppression at high multipoles together with phase-locked features in polarization. It also predicts modest directional variation in modulation strength that can account for hemispheric asymmetry. We support these claims with parameter-free checks and targeted estimators. Test 1 confirms the expected three-sphere marginal for the vector channel using a Kolmogorov–Smirnov test and a truncated equal-probability chi-square test. We then validate the damping law with a phase-free projection that avoids spurious phase alignment, and we estimate the coherence healing rate from data without injecting prior constants. The result is a falsifiable, minimal model that links microscopic lattice geometry to macroscopic sky structure.