A Geometric–Decoherence Bridge Interpretation of the Double-Slit Experiment

This paper presents a unified interpretation of the double-slit experiment linking quantum mechanics, decoherence, and the geometric field framework of the Unified 4D Topological Substrate Theory (U4DTST). The analysis shows how a complex-scalar field τ acts as a physical substrate for quantum phase: local twists manifest as particles, while global phase continuity generates interference. Decoherence and Everettian branching then emerge as limiting behaviours of the same geometric dynamics—measurement corresponds to local coupling that breaks τ-phase continuity. The work demonstrates that wave-particle duality, visibility–distinguishability complementarity, and the appearance of collapse can all be described within a single covariant field picture. Experimental implications include weak-measurement scaling, symmetric “τ-mirror’’ detection, and curvature-induced phase shifts. A full derivation of the τ-field dynamics and covariant action appears in the companion volume The Unified 4D Topological Substrate Theory (U4DTST) [Zenodo DOI: 10.5281/zenodo.17302718].