Probing the cosmic distance duality with strong gravitational lensing and supernovae Ia data

TL;DR

This paper tests the cosmic distance-duality relation using strong gravitational lensing and supernovae data, finding no evidence of violation and supporting the fundamental assumptions of cosmology.

Contribution

It introduces a new method combining SGL and SNe Ia data to test the CDDR, allowing for potential deviations and providing constraints on its validity.

Findings

No violation of the CDDR at 1σ confidence level.

Supports the theoretical foundation of the CDDR.

Reinforces previous tests confirming the CDDR's validity.

Abstract

We propose and perform a new test of the cosmic distance-duality relation (CDDR), $D_L(z) / D_A(z) (1 + z)^{2} = 1$, where $D_A$ is the angular diameter distance and $D_L$ is the luminosity distance to a given source at redshift $z$, using strong gravitational lensing (SGL) and type Ia Supernovae (SNe Ia) data. We show that the ratio $D=D_{A_{12}}/D_{A_2}$ and $D^{*}=D_{L_{12}}/D_{L_{2}}$, where the subscripts 1 and 2 correspond, respectively, to redshifts $z_1$ and $z_2$, are linked by $D/D^*=(1+z_1)^2$ if the CDDR is valid. We allow departures from the CDDR by defining two funcions for $\eta(z_1)$, which equals unity when the CDDR is valid. We find that combination of SGL and SNe Ia data favours no violation of the CDDR at 1$\sigma$ confidence level ($\eta(z) \simeq 1$), in complete agreement with other tests and reinforcing the theoretical pillars of the CDDR.