Testing the distance duality relation using type Ia supernovae and ultracompact radio sources

الأصل · EN

We test the possible deviation of the cosmic distance duality relation Dₐ(z)(1+z)²/Dₗ(z)≡ 1 using the standard candles/rulers in a fully model-independent manner. Type-Ia supernovae are used as the standard candles to derive the luminosity distance Dₗ(z), and ultra-compact radio sources are used as the standard rulers to obtain the angular diameter distance Dₐ(z). We write the deviation of distance duality relation as Dₐ(z)(1+z)²/Dₗ(z)=η(z). Specifically, we use two parameterizations of η(z), i.e. η₁(z)=1+η₀ z and η₂(z)=1+η₀ z/(1+z). The parameter η₀ is obtained using the Markov chain Monte Carlo methods by comparing Dₗ(z) and Dₐ(z) at the same redshift. The best-fitting results are η₀=-0.06± 0.05 and -0.18± 0.16 for the first and second parameterizations, respectively. Our results depend on neither the cosmological models, nor the matter contents or the curvature of the universe.