We prove that four-dimensional SU (3) Yang–Mills theory exists as a quantum field theory and possesses a mass gap Δ > 0, within the BCT Superfluid Lattice framework. The bare SU (3) coupling is fixed geometrically: g2bare = π5/24. The mass gap satisfies Δ ≥ √ (2π) ·ΛQCD ≈ 550 MeV > 0. The proof extends to all compact simple gauge groups via D4 root subsystem decomposition. This constitutes a proof of the Clay Millennium Prize problem for Yang–Mills.
Michel Robert Cabrié (Sun,) studied this question.