Standard Model Embedding and Holonomy Bounds in Scalar–Vector–Spinor Effective Field Theory

We develop the Standard Model matching problem in scalar–vector–spinor effective field theory by separating spacetime Clifford structure, internal gauge representations and compact spectral thresholds. On a single complex irreducible module of , the commutant of the proper Lorentz action is Abelian and cannot carry the Standard Model non-Abelian factors. An explicit internal multiplicity space instead gives a commuting, anomaly-free representation with quadratic indices and . The familiar weak-angle boundary value then follows only after imposing a common gauge kinetic trace. For positive-norm vectorlike fermion towers on a circle, we derive the finite one-loop holonomy threshold and an exact bound on its ability to repair gauge coupling mismatch. A complete generation with a common mass and phase gives only a universal shift. Allowing phase splitting, the sharp bound is saturated by a single hypercharge center holonomy that makes the doublets periodic and the singlets antiperiodic. With stated electroweak inputs and vanishing nonuniversal reference matching, one additional vectorlike generation requires ; three require . These are conditional spectral constraints, not measured compactification bounds. We also identify the boundary data needed for a chiral completion and the additional information required for flavor predictions. Explicit generators, numerical verification and all figure data accompany the manuscript.