The Experiment: D^2 + V^2 ≤ 1 as a Falsifier

This paper turns the Unifier into an experiment. In 2026a, we proved no unital map T → E for H = S^1. In 2026b, we generalized to the triple H^n(T(H)) = (dim H^n, dim C^n, 1) for all finite H, all n. In 2026c, we defined the Bridge Conjecture. In 2026d, we proved the eraser must be CPTP decoherence. In 2026e, we proved all four follow from one Unifier Axiom: [x,y] = 1, and no unital φ: T(H) → E preserves [x,y]. In 2026f, we categorified H. In 2026g, we proved the Unifier survives in characteristic p. In 2026h, we proved it survives for infinite H = lim→ H_i. Here we give the explicit falsifier: a delayed-choice quantum eraser with which-path distinguishability D and interference visibility V must satisfy D^2 + V^2 ≤ 1. If a run with no eraser yields D ≈ 1 and V ≈ 1 repeatably at > 3σ, then (U1) fails, c is not 1, and 2026a/b/c/d/e/f/g/h all fall. If the bound holds, the Unifier survives its first laboratory test. This is not a new theory. It is the protocol that makes the previous eight papers falsifiable. Tseglin 2026i = Ch. 144. Cites Tseglin 2026a DOI 10.5281/zenodo.23977165, 2026b DOI 10.5281/zenodo.23980498, 2026c DOI 10.5281/zenodo.23980738, 2026d DOI 10.5281/zenodo.23981860, 2026e DOI 10.5281/zenodo.23982063, 2026f DOI 10.5281/zenodo.23982359, 2026g DOI 10.5281/zenodo.23985216, 2026h DOI 10.5281/zenodo.23991367.