A late-time informational modification of the cosmological background and the Hubble tension

MCMC chains, analysis scripts, Cobaya configuration files, and publication-quality figures for the CETω (Causal-Informational Completion of Gravity) late-time cosmological modification framework applied to the Hubble tension. This data release contains: (1) Six fully converged Markov Chain Monte Carlo chains produced with Cobaya + a modified version of the CLASS Einstein-Boltzmann solver (v3.3.4). The modification implements a smooth late-time enhancement of the effective dark energy density parametrized as ρ_Λ^eff(z) = ρ_Λ[1 + ε exp(-z/z_c)], with a flat prior ε ≥ 0 consistent with the spectral positivity constraint derived from the Stieltjes kernel structure of the CETω framework. The six chains correspond to three dataset combinations (Planck TTTEEE lite + BOSS DR12 + Pantheon+; Planck + DESI DR1 with full covariance + Pantheon+; Planck + BOSS DR12 + Pantheon+ + SH0ES H₀ prior), each run in paired CETω and ΛCDM configurations with identical likelihood setups. (2) Four Python scripts that reproduce all nine publication figures from the chains and CLASS outputs, including posterior distributions, corner plots, one-dimensional marginals, dataset comparisons, a restricted BAO+SH0ES profile-likelihood scan, a blind DESI DR1 cross-validation, CMB low-multipole ISW consistency checks, and growth-rate fσ₈(z) comparisons with RSD data. (3) Six Cobaya YAML configuration files specifying sampler settings, theory parameters, likelihood modules, and prior definitions for full reproducibility. (4) Nine figures in both PDF (vector) and PNG (600 dpi raster) formats. The CETω framework is mathematically grounded in a nonlocal gravitational operator admitting a Stieltjes integral representation with non-negative spectral density, ensuring ghost freedom, causal propagation, and mode stability. The cosmological analysis finds that the model is statistically equivalent to ΛCDM under the full multi-probe dataset (Δχ² = +0.2 for one additional parameter), while producing a controlled percent-level deviation in late-time distance observables at z ~ 0.3–0.7 that is independently supported by DESI Year 1 BAO measurements.