Investigating the relationship between cosmic curvature and dark energy models with the latest supernova sample

Abstract

We investigate the relationship between cosmic curvature and model of dark energy (hereafter DE) with recent Type Ia supernovae (hereafter SNe Ia) data, i.e., the Pantheon sample including 1048 SNe Ia with 0.01 < z < 2.3. We obtain measurements of the dimensionless spatial curvature density today, i.e., and at 68% confidence level (CL), respectively, in the scenarios of ΛCDM, ϕCDM (i.e., scalar field DE), ωCDM and ω0ωaCDM models. In the scenario of ΛCDM model, a closed universe is preferred by the Pantheon sample, which is consistent with that from the Planck CMB spectra. However, the uncertainty of Ωk0 from the Pantheon SNe sample is about 8 times larger than that from the Planck data, so the former one supports a closed universe at a much lower CL than that from the latter one. An open unverse is supported by the Pantheon sample at ∼32% and ∼78% CLs, respectively, in the ωCDM and ω0ωaCDM models. Among these models, the ϕCDM model is the one which supports the flat universe most strongly. It shows that Ωk0 is significantly dependent on the adopted model of DE, and there is a negative correlation between Ωk0 and the equation of state of DE.