Assessment of the cosmic distance duality relation using Gaussian Process

TL;DR

This study tests the cosmic distance duality relation using Gaussian Process reconstruction from supernova, BAO, and cosmic chronometer data, confirming its validity within 2σ up to redshift 2.

Contribution

It introduces a non-parametric Gaussian Process method to assess the distance duality relation with multiple cosmological datasets, providing a model-independent validation.

Findings

Distance duality relation agrees with data within 2σ up to z=2

Gaussian Process effectively reconstructs distance measures from observational data

Results are consistent across different covariance functions used in GP

Abstract

Two types of distance measurement are important in cosmological observations, the angular diameter distance $d_A$ and the luminosity distance $d_L$. In the present work, we carried out an assessment of the theoretical relation between these two distance measurements, namely the cosmic distance duality relation, from type Ia supernovae (SN-Ia) data, the Cosmic Chronometer (CC) Hubble parameter data, and baryon acoustic oscillation (BAO) data using Gaussian Process. The luminosity distance curve and the angular diameter distance curve are extracted from the SN-Ia data and the combination of BAO and CC data respectively using the Gaussian Process. The distance duality relation is checked by a non-parametric reconstruction using the reconstructed $H$, $d_L$, and the volume-averaged distance $D_v$. We compare the results obtained for different choices of the covariance function employed in the Gaussian Process. It is observed that the theoretical distance duality relation is in well agreement with the present analysis in 2$\sigma$ for the overlapping redshift domain $0 \leq z \leq 2$ of the reconstruction.