Interacting scenarios with dynamical dark energy: Observational constraints and alleviation of the $H_0$ tension

We investigate interacting scenarios that belong to a wider class, since they include a dynamical dark energy component whose equation of state follows various one-parameter parametrizations. We confront them with the latest observational data from the cosmic microwave background, the joint light-curve sample from type Ia supernovae, baryon acoustic oscillations, Hubble parameter measurements from cosmic chronometers (CC), and a Gaussian prior on the Hubble parameter $H_0$. In all examined scenarios we find a nonzero interaction; nevertheless, the noninteracting case is allowed within $2\sigma$. Concerning the current value of the dark energy equation of state for all combinations of data sets, it always lies in the phantom regime at more than 2–3 standard deviations. Finally, for all interacting models, independently of the combination of data sets considered, the estimated values of the present Hubble parameter $H_0$ are greater compared to the $\mathrm{\Lambda }\mathrm{CDM}$-based Planck estimate and close to the local measurements, thus alleviating the $H_0$ tension.

Figure 1

The 68% and 95% C.L. contour plots between various combinations of the model parameters of scenario IDE1, using different observational astronomical data sets. Additionally, we display the one-dimensional marginalized posterior distributions of some free parameters.

Figure 2

The 68% and 95% C.L. contour plots between various combinations of the model parameters of scenario IDE1 using only the $\mathrm{CMB}+\mathrm{BAO}$ and $\mathrm{CMB}+\mathrm{BAO}+\mathrm{R}19$ data sets, and the corresponding one-dimensional marginalized posterior distributions.

Figure 3

Whisker plot with the 68% C.L. constraints on the Hubble constant for all interacting models and all combinations of data sets considered in this work. The grey vertical band corresponds to the R19 value for the Hubble constant $H_0$, as measured by SH0ES in Ref. [113], and the red vertical band is the estimate from the Planck 2018 release [116].

Figure 4

The 68% and 95% C.L. contour plots between various combinations of the model parameters of scenario IDE2, using different observational astronomical data sets. Additionally, we display the one-dimensional marginalized posterior distributions of some of the free parameters.

Figure 5

The 68% and 95% C.L. contour plots between various combinations of the model parameters of scenario IDE2 using only the $\mathrm{CMB}+\mathrm{BAO}$ and $\mathrm{CMB}+\mathrm{BAO}+\mathrm{R}19$ data sets, and the corresponding one-dimensional marginalized posterior distributions.

Figure 6

The 68% and 95% C.L. contour plots between various combinations of the model parameters of scenario IDE3, using different observational astronomical data sets. Additionally, we display the one-dimensional marginalized posterior distributions of some free parameters.

Figure 7

The 68% and 95% C.L. contour plots between various combinations of the model parameters of scenario IDE3 using only the $\mathrm{CMB}+\mathrm{BAO}$ and $\mathrm{CMB}+\mathrm{BAO}+\mathrm{R}19$ data sets, and the corresponding one-dimensional marginalized posterior distributions.

Figure 8

The 68% and 95% C.L. contour plots between various combinations of the model parameters of scenario IDE4, using different observational astronomical data sets. Additionally, we display the one-dimensional marginalized posterior distributions of some free parameters.

Figure 9

The 68% and 95% C.L. contour plots between various combinations of the model parameters of scenario IDE4 using only the $\mathrm{CMB}+\mathrm{BAO}$ and $\mathrm{CMB}+\mathrm{BAO}+\mathrm{R}19$ data sets, and the corresponding one-dimensional marginalized posterior distributions.