Testing the isotropy of the Universe with type Ia supernovae in a model-independent way
Wang, Y. Y. · Wang, F. Y.
Original · EN
In this paper, we study an anisotropic universe model with Bianchi-I metric using Joint Light-curve Analysis (JLA) sample of type Ia supernovae (SNe Ia). Because light-curve parameters of SNe Ia vary with different cosmological models and SNe Ia samples, we fit the SNe Ia light-curve parameters and cosmological parameters simultaneously employing Markov Chain Monte Carlo method. Therefore, the results on the amount of deviation from isotropy of the dark energy equation of state (δ), and the level of anisotropy of the large-scale geometry (Σ₀) at present, are totally model-independent. The constraints on the skewness and cosmic shear are -0.101<δ<0.071 and -0.007<Σ₀<0.008. This result is consistent with a standard isotropic universe (δ=Σ₀=0). However, a moderate level of anisotropy in the geometry of the Universe and the equation of state of dark energy, is allowed. Besides, there is no obvious evidence for a preferred direction of anisotropic axis in this model.
English translation
This paper has no Arabic translation yet. Be the first: it takes a few seconds, and the result is stored for every future reader.