Redshift Duality with Pantheon+SH0ES in a Planck-anchored Flat $Λ$CDM Framework: Implications for Hubble Tension and Observational Inference

Abstract

We test an operationally defined redshift duality in which the observed redshift comprises the standard metric-expansion component together with an additional line-of-sight quantum contribution arising from the cumulative conversion of photon energy into effective mass as a function of path length and frequency. Fitting this hybrid model to the Pantheon+SH0ES compilation, we find that the metric-expansion Hubble constant, $H_Λ$, is recovered to a value consistent with the Planck baseline of $67.4~\mathrm{km\,s^{-1}\,Mpc^{-1}}$ within $\lesssim 0.33σ$. Redshift-binned analyses show that while the flat Lambda cold dark matter ($Λ$CDM) model produces an apparent drift in the inferred Hubble parameter across the Hubble flow, the hybrid model restores the constancy of $H_Λ$ across redshift bins. The correctional trends of cosmological physical quantities re-inferred under this framework further indicate the potential to alleviate anomalies associated with high-redshift galaxies. These results suggest that redshift duality warrants further consideration in observational processing and inference, while preserving consistency with a Planck-anchored flat $Λ$CDM baseline.