Constraining the anisotropy of the Universe with the Pantheon supernovae sample

Zhe Chang, Dong Zhao, Yong Zhou
2019 Chinese Physics C, High Energy Physics & Nuclear Physics  
We test the possible dipole anisotropy of a Finslerian cosmological model and other three dipole-modulated cosmological models, i.e., the dipole-modulated $\rm{\Lambda}$CDM, $w$CDM and Chevallier--Polarski--Linder (CPL) model by using the recently released Pantheon sample of SNe Ia. The Markov chain Monte Carlo (MCMC) method is used to explore the whole parameter space. We find that the dipole anisotropy is very weak in all cosmological models used. Although the dipole amplitudes of four
more » ... udes of four cosmological models are consistent with zero within $1\sigma$ uncertainty, the dipole directions are close to the axial direction to the plane of SDSS subsample among Pantheon. It may imply that the weak dipole anisotropy in the Pantheon sample originates from the inhomogeneous distribution of the SDSS subsample. More homogeneous distribution of SNe Ia is necessary to constrain the cosmic anisotropy.
doi:10.1088/1674-1137/43/12/125102 fatcat:3uvjizjnazbxpcwr27dmi6rqji