Cosmological-model-independent tests of cosmic distance duality relation with Type Ia supernovae and radio quasars

Understand

In this paper, we investigate the possible deviations of the cosmic distance duality relation (CDDR) using the combination of the largest SNe Ia (Pantheon) and compact radio quasar (QSO) samples through two model-independent approaches.

• The deviation of CDDR is written as $D_L(z)/D_A(z)(1+z)^{-2}=\eta(z)$ and $\eta(z)=e^{\tau(z)/2}$, with the parameterizations of $F_1$ ($\tau(z) = 2\epsilon_1 z$) and $F_2$ ($\tau(z) = (1+z)^{2\epsilon_2}-1$).
• Furthermore, in order to compare the two resulting distances, two cosmological-model-independent methods, i.e., the nearby SNe Ia method and the GP method are employed to match the two distinct data at the same redshift.
• Our findings indicate that, compared with the results obtained in the literature, there is an improvement in precision when the latest SNe Ia and QSO samples are used.