General Cosmography Model with Spatial Curvature
Abstract
The cosmographic approach is adopted to determine the spatial curvature (i.e., ) combining the latest released cosmic chronometers data (CC), the Pantheon sample of type Ia supernovae observations, and the baryon acoustic oscillation measurements. We use the expanded transverse comoving distance as a basic function for deriving and the other cosmic distances. In this scenario, can be constrained only by CC data. To overcome the convergence issues at high-redshift domains, two methods are applied: the Pad\'{e} approximants and the Taylor series in terms of the new redshift . Adopting the Bayesian evidence, we find that there is positive evidence for the Pad\'{e} approximant up to order () and weak evidence for the Taylor series up to 3-rd order against model. The constraint results show that a closed universe is preferred by the present observations under all the approximants used in this study. And the tension level of the Hubble constant is less than significance between different approximants and the local distance ladder determination. For each assumed approximant, is anti-correlated with and the sound horizon at the end of the radiation drag epoch, which indicates that the tension problem can be slightly relaxed by introducing or any new physics which can reduce the sound horizon in the early universe.
Cite
@article{arxiv.1903.11433,
title = {General Cosmography Model with Spatial Curvature},
author = {En-Kun Li and Minghui Du and Lixin Xu},
journal= {arXiv preprint arXiv:1903.11433},
year = {2020}
}
Comments
13 pages, 4 figures, major revised, update data and conclusions