Sovereign Scaling Resonance (SSR): an Oscillatory Dark Energy Extension of ΛCDM with Cosmological Constraints and Laboratory Falsifiability

This preprint presents the Sovereign Scaling Resonance (SSR) model — a pseudo-scalar dark energy field governed by a cosine potential whose vacuum scale is anchored to the Planck–proton mass-ratio hierarchy. The oscillatory equation of state w(z) ≈ −1 + A·sin[ω·ln(1+z) + φ] is derived analytically from the field action via WKB treatment, not postulated. The shift symmetry of the cosine potential mandates an axion–photon coupling by standard effective field theory, connecting the cosmological model to near-future laboratory experiments. Key results: MCMC constraints (259,870 steps, R−1 = 0.011): H₀ = 70.76 ± 0.87 km/s/Mpc, Ω_m = 0.2715, A = 0.031, ω = 5.40 ± 0.70, f_M = 0.503 ± 0.32 M_pl S8 amplitude tension improvement: Δχ²_growth = −22.11 (driven by KiDS-1000 and DES Y3 S8 priors) ISW check via exact CAMB (tabulated w(a)): 0.516% RMS over ℓ = 2–30, factor ~10–19 below Planck detection threshold Field mass m_Ξ ≈ 5 meV (68% CI: 3–13 meV) falls in the CAST-IAXO and PVLAS-FIN target range ΔBIC = +48.6 (honest range +21 to +48.6 after effective degrees-of-freedom correction) Data and code: MCMC chains and analysis pipeline available at doi:10.5281/zenodo.20260778 and github.com/impulsiveaura/ssr-dark-energy The current evidence state is best characterised as "interesting and worth pursuing": the model makes genuine theoretical contributions but does not yet compel preference over ΛCDM. Decisive experimental tests are expected within ~5 years via CAST-IAXO, Euclid, and DESI Year 5.