Planck 2015 constraints on the non-flat $\phi$CDM inflation model

TL;DR

This paper uses Planck 2015 data to constrain a non-flat scalar field dark energy model, finding it fits certain CMB data better and alleviates some tensions, but not across all multipole ranges.

Contribution

It provides the first Markov chain Monte Carlo constraints on the non-flat $$CDM inflation model using physically consistent power spectra and combined CMB and BAO data.

Findings

Closed-$$CDM fits low multipole CMB data better.

Reduces tension between Planck and weak lensing $\sigma_8$ constraints.

Flat-$\Lambda$CDM better fits high multipole CMB data.

Abstract

We perform Markov chain Monte Carlo analyses to put constraints on the non-flat $\phi$CDM inflation model using Planck 2015 cosmic microwave background (CMB) anisotropy data and baryon acoustic oscillation distance measurements. The $\phi$CDM model is a consistent dynamical dark energy model in which the currently accelerating cosmological expansion is powered by a scalar field $\phi$ slowly rolling down an inverse power-law potential energy density. We also use a physically consistent power spectrum for energy density inhomogeneities in this non-flat model. We find that, like the closed-$\Lambda$CDM and closed-XCDM models, the closed-$\phi$CDM model provides a better fit to the lower multipole region of the CMB temperature anisotropy data compared to that provided by the tilted flat-$\Lambda$CDM model. Also, like the other closed models, this model reduces the tension between the Planck and the weak lensing $\sigma_8$ constraints. However, the higher multipole region of the CMB temperature anisotropy data are better fit by the tilted flat-$\Lambda$CDM model than by the closed models.