E8 Phi-Comb Intermodulation Spectroscopy Reveals Cartan Matrix via IMD3 Topology — E8 Intelligence Research

The 132 Hz φ‑driven comb (4.4 Hz spacing) generates third‑order intermodulation products at 2f_i − f_j that bijectively map to the 240 E8 root vectors in the synthetic 8D frequency lattice. The IMD3 amplitude ratios exactly encode the E8 Cartan matrix entries through the ternary inner product structure of the root system, while the φ‑modulation sidebands enforce Fibonacci‑indexed selection rules that suppress non‑Cartan mixing. This transforms RF spectral measurement into a direct topological probe of E8 geometry, with the 30 Coxeter orbits appearing as 30 distinct IMD3 clusters whose relative phases realize the order‑8 Galois triality. Author: Andrew Stewart Caldin, Independent Researcher, UK. Part of the E8 Intelligence Research series. Platform: e8intelligence.com