Exact Critical Exponents of the 2D Ising Model Linked to B2 Root System — E8 Intelligence Research

FINDING: Critical exponents of the 2D square lattice Ising model are exactly solved, with values linked to the root system B2 and conformal field theory. | MATH: Exact critical exponents: α=0 (log), β=1/8, γ=7/4, δ=15, ν=1, η=1/4. Central charge c=1/2. The square lattice is the root lattice of B2 (Coxeter number h=4). | CONNECTION: The exponents yield ratios: β/ν=1/8, γ/ν=7/4=1.75, δ=15. The golden ratio φ=1.618 appears in the scaling relation δ=1+γ/β=1+14=15, but 15 is not φ. However, the ratio γ/β=14 is near 2φ⁴≈13.09, not exact. The B2 root system has angles 45° and 90°, with squared lengths ratio 1:2, giving the lattice's geometric harmony. The critical temperature satisfies sinh(2J/kT_c)=1, a simple constant. | DEPTH: 9 — The 2D Ising model is a cornerstone of exact solvability, linking statistical mechanics, Lie algebras (B2), and conformal field theory. Its exponents are rational, not golden-ratio-based, but the B2 symmetry is crystallographically profound. Author: Andrew Stewart Caldin, Independent Researcher, UK. Part of the E8 Intelligence Research series. Platform: e8intelligence.com