Planck 2015 constraints on spatially-flat dynamical dark energy models

• Published in: Astrophysics and space science Vol. 364; no. 10; pp. 1 - 8
• Main Authors: Ooba, Junpei, Ratra, Bharat, Sugiyama, Naoshi
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.10.2019; Springer Nature B.V; Springer
• Subjects: Anisotropy; Astrobiology; Astronomical models; Astronomy; ASTRONOMY AND ASTROPHYSICS; Astrophysics; Astrophysics and Astroparticles; Constraints; Cosmic background radiation; Cosmic microwave background; cosmological parameters; Cosmology; Dark energy; Distance measurement; Flux density; large-scale structure of universe; observations; Observations and Techniques; Original Article; Parameterization; Physics; Physics and Astronomy; Potential energy; Power law; Space Exploration and Astronautics; Space Sciences (including Extraterrestrial Physics; Cosmological parameters; Observations; Large-scale structure of universe; Cosmic background radiation
• ISSN: 0004-640X; 1572-946X
• DOI: 10.1007/s10509-019-3663-4

We determine constraints on spatially-flat tilted dynamical dark energy XCDM and ϕ CDM inflation models by analyzing Planck 2015 cosmic microwave background (CMB) anisotropy data and baryon acoustic oscillation (BAO) distance measurements. XCDM is a simple and widely used but physically inconsistent parameterization of dynamical dark energy, while the ϕ CDM model is a physically consistent one in which a scalar field ϕ with an inverse power-law potential energy density powers the currently accelerating cosmological expansion. Both these models have one additional parameter compared to standard Λ CDM and both better fit the TT + lowP + lensing + BAO data than does the standard tilted flat- Λ CDM model, with Δ χ 2 = − 1.26 ( − 1.60 ) for the XCDM ( ϕ CDM) model relative to the Λ CDM model. While this is a 1.1 σ (1.3 σ ) improvement over standard Λ CDM and so not significant, dynamical dark energy models cannot be ruled out. In addition, both dynamical dark energy models reduce the tension between the Planck 2015 CMB anisotropy and the weak lensing σ 8 constraints.