Constraints on Cosmic Distance Duality Relation from Cosmological Observations

TL;DR

This study tests the cosmic distance duality relation using various cosmological observations, finding no significant deviation from the expected relation and projecting future data could tighten these constraints.

Contribution

It provides the most stringent current constraints on the cosmic opacity parameter by combining multiple observations and explores potential evolution of this parameter with redshift.

Findings

Current data do not show deviation from the CDDR.

Combined observations constrain the opacity parameter to $oxed{0.023 extpm0.018}$.

Future data could significantly improve the constraints on cosmic opacity.

Abstract

In this paper, we use the model dependent method to revisit the constraint on the well-known cosmic distance duality relation (CDDR). By using the latest SNIa samples, such as Union2.1, JLA and SNLS, we find that the SNIa data alone can not constrain the cosmic opacity parameter $\varepsilon$, which denotes the deviation from the CDDR, $d_{\rm L} = d_{\rm A}(1+z)^{2+\varepsilon}$, very well. The constraining power on $\varepsilon$ from the luminosity distance indicator provided by SNIa and GRB is hardly to be improved at present. When we include other cosmological observations, such as the measurements of Hubble parameter, the baryon acoustic oscillations and the distance information from cosmic microwave background, we obtain the tightest constraint on the cosmic opacity parameter $\varepsilon$, namely the 68\% C.L. limit: $\varepsilon=0.023\pm0.018$. Furthermore, we also consider the evolution of $\varepsilon$ as a function of $z$ using two methods, the parametrization and the principle component analysis, and do not find the evidence for the deviation from zero. Finally, we simulate the future SNIa and Hubble measurements and find the mock data could give very tight constraint on the cosmic opacity $\varepsilon$ and verify the CDDR at high significance.