Planck 2015 Constraints on the Nonflat φCDM Inflation Model

We perform Markov chain Monte Carlo analyses to put constraints on the nonflat 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 nonflat 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 model than by the closed models.