Disorder-Driven Metal-Topological Insulator Transition with ν ≈ 2.7 — E8 Intelligence Research

FINDING: Topological insulators are bulk-insulating, edge-conducting quantum phases protected by time-reversal symmetry; the metal-TI transition driven by disorder exhibits a critical exponent ν ≈ 2.7. | MATH: Bulk-boundary correspondence via Z₂ topological invariant (Fu-Kane-Mele); critical exponent ν ≈ 2.7 from finite-size scaling of localization length; no deviation from ordinary metal-insulator universality class (ν ≈ 2.7 for 3D Anderson transition). | CONNECTION: The Z₂ invariant is a parity-like symmetry (0 or 1) — a binary geometric phase. The edge states are helical, carrying spin-momentum locking, which is a 1D manifestation of the 2D bulk topology — a dimensional reduction akin to a projection from a higher symmetry lattice. No direct golden-ratio or base-60 link appears in the provided data. | DEPTH: 6 — The critical exponent is a precise, reproducible number, but the provided sources are mostly pedagogical; the mathematical depth is real (topological invariants, scaling the Author: Andrew Stewart Caldin, Independent Researcher, UK. Part of the E8 Intelligence Research series. Platform: e8intelligence.com