Quantum Field Theory as an Interface Algebra in Entanglement-Algebraic Spacetime

This paper is archived as a speculative research work. We reconstruct quantum eld theory as an interface-level description arising from a single scalarassignment Φ : X → R+ , without assuming spacetime, particles, elds, or dynamics as fundamentalprimitives. Building on the kernel and interface framework established in Labhard [1, 2, 3], we showthat the breakdown of localization and trajectories at small scales necessitates an algebraic represen-tation of interface-level admissibility relations. Algebraic quantum eld theory (AQFT) is adoptedas the minimal interface language compatible with causality once geometry fails. Microcausality isderived from interface-level admissibility compatibility rather than imposed geometrically, and quan-tum states are reinterpreted as summaries of interface-accessible relations among observables. Mass,energy, and particles emerge as algebraic invariants and excitations, not as ontological constituents.We demonstrate explicitly that standard quantum eld theory is recoverable within this frameworkby reconstructing a free scalar eld from admissibility-compatible correlation data and by mappingthe resulting structure to the HaagKastler axioms. Finally, we identify the domain of validity ofthe algebraic interface and show that its breakdown at the Planck scale reects admissibility satu-ration and failure of algebraic closure, not physical inconsistency. These results establish quantumeld theory as a stable but non-fundamental interface within a unied scalar-eld reconstruction ofphysics.