STAY CURRENT All current versions of the UTI framework papers are available here: https://linktr.ee/uti_papers VERSION 2.5 Author: Christopher Gu [ georgeguiscool@gmail.com ] Software Developer based in El Monte, California, USAApril 2026 Abstract The Universal Topological Impedance (UTI) framework derives a short-range scalar η from the QCD trace-trace correlator in the scalar-isoscalar 0++ channel, with characteristic mass mη ≈ 450 MeV and correlation length ξη = ℏc/mη ≈ 0.44 fm. Impedance Contrast Theory (ICT) identifies the de Sitter horizon as the infrared scale setting the transition acceleration a0 = cH0/(2π). We combine these two inputs into a constructive Scale-4 model of dark energy in which a collective horizon phase ΘH(t) is introduced as the zero mode of a postulated horizon-sector phase variable whose coupling to bulk physics is through the trace-channel spectral-asymmetry of local weak and hadronic events rather than through direct bulk propagation of the short-range η field, and the dark-energy density is identified with a periodic horizon-boundary potential ρΛ = χH(1 − cos ΘH), where χH has units of energy density. We establish four quantitative results. (i) The horizon cell count from the UTI coherence length: Ncell = 2(c/H0ξη)^2 = 1.82 × 10^83. (ii) The horizon susceptibility scale from the chirally-suppressed part of the QCD trace anomaly: EχH ≡ χH^(1/4) ≈ √(m̄q·ΛQCD) ≈ 26.5 MeV, which with EΛ = 2.30 meV gives ΘH ≈ 1.1 × 10^−20. (iii) A conditional derivation of the leading even-order structure of the per-event APS spectral-asymmetry shift, ΔηAPS(a) = Ca(ΔMtr(a)/mη)^2 + O((ΔMtr/mη)^4), from the Bismut–Freed first-variation identity under the explicit spectral-symmetry assumption JD0J^−1 = −D0, JVJ^−1 = +V, together with pole-dominance estimates of the channel-dependent coefficients Ca giving CHe ~ 0.3, Cα ~ 0.1, Cβ ~ 0.03, and Ca ≥ 0 for coherent trace-channel-building transitions. (iv) A computation of the present-day adiabatic ratio Θ̇H/(HΘH) ≈ 4 × 10^−4, yielding a predicted deviation from a pure cosmological constant of |weff+1| ≈ 2 × 10^−4 (with a factor-of-several theoretical uncertainty band, Section 9.1) — consistent with current Planck+DESI bounds and potentially detectable by next-generation surveys. Fluctuations across the Ncell independent horizon domains are suppressed on the l=0 projection by a factor √Neff/Ncell ≈ 10^−40, giving a coherent horizon-phase signal-to-noise ratio ≈ 10^39. Within the present phenomenological Scale-4 ansatz, the dark-energy problem is reduced to a sharply defined operator problem: compute the trace-channel spectral-asymmetry shift per weak or hadronic event. NOTE This paper essentially replaces Dark Energy from Topological Decay - https://zenodo.org/records/19391183