Electromagnetic Coupling Without Fundamental Scalars: Structural Invariants and the Emergence of Effective Constants

This work examines the ontological status of electromagnetic coupling, addressing whether the interaction must fundamentally exist as a scalar constant or whether scalar representations arise only as effective projections of deeper invariant structure. Using a constraint-driven quantum–causal simulation framework that prohibits insertion of empirical constants or phenomenological tuning, electromagnetic interaction is shown to converge robustly to a unique, topology-independent fixed point. The interaction remains stable under extreme perturbation yet consistently resists enforced scalar collapse. These results indicate that scalar quantities such as the fine-structure constant do not define electromagnetic interaction at a fundamental level, but instead emerge through regime-dependent projection into restricted observational or theoretical frameworks. The findings align with renormalization behavior, lattice gauge interpretations, and effective field theory, while reframing longstanding questions about the nature of fundamental constants.