Pantheon+ and Redshift Observational Analysis of the UMH Redshift Formulation

This release presents a data-driven observational analysis of the Ultronic Medium Hypothesis (UMH) redshift formulation and luminosity relation against Type Ia supernova observations. The primary analysis uses the Pantheon+ sample and applies two independent pipelines: (1) a low-redshift calibration of the UMH redshift relation for z ≤ 0.10, and (2) a full Pantheon+ Hubble-diagram comparison using the complete STAT+SYS covariance matrix, including both statistical and systematic uncertainties. The low-redshift calibration yields α = (2.48 ± 0.08) × 10⁻⁴ Mpc⁻¹, corresponding to H₀ = 74.4 ± 2.3 km s⁻¹ Mpc⁻¹. In the UMH formulation, α is the single cosmological redshift-scale parameter and is fixed by the low-z calibration. The broadband transmission coefficients β₁ and β₂ enter only through the luminosity/transmission relation and are held fixed after calibration. Under the conditional final-fit convention used in the Hubble-diagram comparison, only parameters varied in the final likelihood are counted: the UMH fit has k = 1, corresponding to the profiled intercept M₀, while the flat ΛCDM reference has k = 2, corresponding to M₀ and the fitted matter-density parameter Ωₘ. Under this convention, the Pantheon+ comparison gives ΔAIC = −2.2 and ΔBIC = −7.6. This version also includes an independent DES-SN5YR/Dovekie validation. Applying the same UMH final-fit and transmission-recovery procedure to the DES-SN5YR Hubble diagram, with α fixed to the Pantheon+/Cepheid calibration, recovers consistent transmission coefficients, β₁ ≃ 0.435 and β₂ ≃ −0.275. With these coefficients fixed and only M₀ profiled, the DES-SN5YR UMH fit is statistically indistinguishable from the flat ΛCDM reference fit. Bidirectional fixed-coefficient transfer tests further show that the Pantheon+ and DES-SN5YR fits do not rely on dataset-specific retuning of β₁ and β₂. Overall, the analysis shows that the UMH formulation reproduces the Pantheon+ distance-redshift relation and the associated (1 + z) time-dilation scaling within the Type Ia supernova Hubble-diagram framework. The DES-SN5YR recovery test supports interpreting β₁ and β₂ as stable transmission-calibration coefficients rather than Pantheon+-specific fit absorbers. At the same time, the manuscript explicitly narrows the interpretation: Type Ia supernova observables alone do not uniquely determine the underlying physical mechanism responsible for cosmological redshift, nor do they establish full cosmological viability without independent tests such as BAO, CMB anisotropies, structure growth, weak lensing, Big Bang nucleosynthesis, gravitational-wave standard sirens, and the full expansion history. Repository Notes: This version supersedes earlier releases and incorporates expanded observational analysis, additional consistency tests, revised diagnostics, and explanatory material developed during peer review. The underlying UMH redshift formulation remains unchanged; the revisions primarily improve validation breadth, statistical transparency, parameter accounting, diagnostic robustness, and scientific communication. The release includes the revised manuscript and associated analysis materials for the Pantheon+ and DES-SN5YR Type Ia supernova consistency tests.