Regime Gauge Geometry Curvature, Yang–Mills Structure and Mass from CoAct in Basic Ontodynamics

Regime Gauge Geometry develops the gauge-theoretic structure of Basic Ontodynamics. We show that the coherence bundle over the regime manifold carries a natural connection induced by the projective structure of coherent ray space. The connection is not postulated but derived from the requirement of compatibility between local phase transport and phase-difference observables. The Yang–Mills action emerges as the unique minimal local gauge-invariant functional of curvature at lowest derivative order (canonical dimension ≤ 4), given the FubiniStudy metric on coherent ray space. This is stated as a structural proposition. The CoAct transition is identified as a structural analogue of spontaneous symmetry breaking. The coherence activation scalar σ(x) = √Ψ†(x)Ψ(x) plays the role of an order parameter. Mass arises not from a primitive Higgs field but from the depth of CoAct transition, identified with the vacuum expectation value of the coherence order parameter. The gauge groups U (1), SU (2), SU (3) arise from the phase symmetry and internal-frame structure of regime multiplets. The framework provides a structural route to the Standard Model gauge architecture as a consequence of coherence geometry and admissible regime dynamics.