A model-independent test of the cosmic distance-duality relation using galaxy clusters and Type Ia supernovae matched pairs

Abstract

The cosmic distance-duality relation (CDDR), expressed as $ D_L/D_A(1+z)^{-2}=1 $, is a fundamental relation in cosmology connecting luminosity distance ($ D_L $) and angular diameter distance ($ D_A $). Any departure from this relation would indicate new physics such as photon non-conservation, cosmic opacity, or non-metric gravity. We perform a stringent, model-independent test of the CDDR using a matched sample of 38 galaxy clusters from the Bonamente et al. compilation and Type Ia supernovae from the Pantheon+ sample. Employing the matched-pair technique, we simultaneously constrain the CDDR-violation parameter $ \eta $ and a possible redshift evolution of the SNe Ia absolute magnitude, parameterized as $ M_B(z)=M_0 + \varepsilon z $. We assess the robustness against matching tolerance and further supplement the analysis with DESI 2024 BAO measurements. Our results yield $ \eta = 0.050^{+0.348}_{-0.307} $ and $ \varepsilon = -0.184^{+0.724}_{-0.574} $ (68% CL), showing no statistically significant evidence for CDDR violation or SNe Ia evolution. The conclusions remain unchanged with stricter matching criteria and the inclusion of DESI BAO data. We also derive a cosmology-independent calibration of $ M_0 = -19.460^{+0.126}_{-0.124} $ mag. The standard cosmological model remains robust under this model-independent scrutiny.