Signs of Dynamical Dark Energy in Current Observations

Abstract

Investigations on dark energy (DE) are currently inconclusive about its time evolution. Hints of this possibility do however glow now and then in the horizon. Herein we assess the current status of dynamical dark energy (DDE) in the light of a large body of updated $SNIa+H(z)+BAO+LSS+CMB$ observations, using the full Planck 2015 CMB likelihood. The performance of the $\Lambda$CDM model (with equation of state $w=-1$ for $\Lambda$) is confronted with that of the general XCDM and CPL parametrizations, as well as with the traditional $\Phi$CDM model based on the scalar field potential $V\sim {\Phi }^{-\alpha }$. In particular, we gauge the impact of the bispectrum in the LSS and BAO parts, and show that the subset of $CMB+BAO+LSS$ observations may contain the bulk of the DDE signal. The departure from $w=-1$ is significant: roughly $2.6\sigma$ for XCDM and $2.9\sigma$ for $\Phi$CDM. In both cases the full Bayesian evidence is found to be positive even for a prior range of the DDE parameters extending over several standard deviations from the mean when the bispectrum is taken into account. Positive signs follow as well from the preliminary results of Planck 2018 data using the compressed CMB likelihood. As a bonus we also find that the ${\sigma }_8$-tension becomes reduced with DDE.

arXiv commentPublished in Physics of the Dark Universe 25 (2019) 100311

References in corpus (8)

• Distance Priors from Planck Final Release
• Beyond $\Lambda$CDM with Low and High Redshift Data: Implications for Dark Energy
• Constraints on the interacting vacuum -- geodesic CDM scenario
• Using the tilted flat-$\Lambda$CDM and the untilted non-flat $\Lambda$CDM inflation models to measure cosmological parameters from a compilation of observational data
• Observational constraints on the tilted spatially-flat and the untilted nonflat $\varphi$CDM dynamical dark energy inflation models
• Measuring the Hubble constant and spatial curvature from supernova apparent magnitude, baryon acoustic oscillation, and Hubble parameter data
• Testing dynamical vacuum models with CMB power spectrum from Planck
• Marginal Likelihoods from Monte Carlo Markov Chains

Cited by in corpus (9)

• Constraints on the interacting vacuum -- geodesic CDM scenario
• Baryon acoustic oscillation, Hubble parameter, and angular size measurement constraints on the Hubble constant, dark energy dynamics, and spatial curvature
• Using the tilted flat-$\Lambda$CDM and the untilted non-flat $\Lambda$CDM inflation models to measure cosmological parameters from a compilation of observational data
• Quantifying the evidence for the current speed-up of the Universe with low and intermediate-redshift data. A more model-independent approach
• Generalized thermodynamic constraints on holographic-principle-based cosmological scenarios
• Constraints on field flows of quintessence dark energy
• First study of reionization in tilted flat and untilted non-flat dynamical dark energy inflation models
• Dynamic properties of cyclic cosmologies
• Signs of Interacting Vacuum and Dark Matter in the Universe