2017/11/16 by Y. Y. Wang, Yu-Yang Wang, F. Y. Wang · 44 citations
Physics and Astronomy · #Anisotropy #Astrophysics #Cosmology #Cosmology and Gravitation Theories #Dark energy #Deceleration parameter #Equation of state #Gamma-ray bursts and supernovae #Isotropy #Light curve #Metric expansion of space #Physics #Quantum mechanics #Shape of the universe #Stellar, planetary, and galactic studies #Supernova #Universe #astro-ph.CO
paper · pdf · doi:10.1093/mnras/stx2982
published in Monthly Notices of the Royal Astronomical Society 474(3), 3516-3522 (Oxford University Press) · 10 pages, 5 figures, 5 tables, accepted for publication in MNRAS
arxiv created 2017/11/16 · openalex publication_date 2017/11/17 · arxiv updated 2017/12/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Abstract 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.