Towards a Chronology Protection Law from Which-Path Erasure: Decoherence as Vacuum Divergence from Unruh-DeWitt Coupling — v4 formalization of concept from Sept 21, 2020

Concept first proposed conceptually in self-published treatise on Sept 21, 2020 (30pp, Amazon KDP) as: "the universe erases the past to comply with its own laws, triggered by measurement in the double slit as a fundamental force like gravity." v4 formalization (Nov 3, 2026): We replace circular consistency projector P_consistency with Lorentz-invariant Θ(s^2), s^2=c^2Δt^2-|Δx|^2. We couple Unruh-DeWitt detector to scalar field in Morris-Thorne wormhole with time shift ΔT, Wightman image sum W=Σ 1/[(t-t'-nΔT)^2 - ...]. Derivation yields |<E2|E1>| = exp[-ΔT^2/2T_P^2] far from horizon, →0 at ΔT_c=L/c, where T_P^2=ħG/c^5. This proves in toy model <T_μν>→infinity iff <E2|E1>→0. Vacuum divergence is identified as which-path decoherence. Force: F_c = -k_B T_dS ∇ log Tr(E) = k_B T_dS ΔT/T_P^2, diverging at chronology horizon. Falsifiable prediction: V(ΔT)=exp[-ΔT^2/2T_P,sim^2] testable on IBM Quantum with Lloyd post-selected CTC circuit. Ancillary Qiskit code in appendix. Original 2020 concept: 2020-09-21. Formalization v4: 2026-11-03. References: Hawking PRD 46,603 (1992), Visser gr-qc/0204023, Brun gr-qc/0209061, Deutsch PRD 44,3197, Lloyd PRL 106,040403, Zurek Phys Today, Birrell & Davies. DOI: 10.5281/zenodo.23914171