Smoothing the H0 tension with a phantom dynamical dark energy model

The discrepancy between Planck data and direct measurements of the current expansion rate H0 and the matter fluctuation amplitude S8 has become one of the most intriguing puzzles in cosmology nowadays. The H0 tension has reached 5 & sigma; in the context of standard cosmology i.e ?CDM. Therefore, explanations to this issue are mandatory to unveil its secrets. Despite its success, ?CDM is unable to give a satisfying explanation to the tension problem. Unless some systematic errors are hidden in the observable measurements, physics beyond the standard model of cosmology must be advocated. In this perspective, we study a phantom dynamical dark energy model as an alternative to ?CDM in order to explain the aforementioned issues. This phantom model is characterized by one extra parameter, S2pdde, compared to ?CDM. We obtain a strong positive correlation between H0 and S2pdde, for all data combinations. Using Planck18 measurements together with BAO and Pantheon, we find that the H0 and the S8 tensions are 3.4 & sigma; and 2.75 & sigma;, respectively. By introducing a prior on the absolute magnitude, MB, of the SN Ia, the H0 tension decreases to 2.49 & sigma; with H0 = 69.7+0.83 -0.86 km s-1 Mpc-1 and the S8 tension reaches the value 2.51 & sigma; with S8 = 0.8265+0.011 0.012 .& COPY; 2023 Elsevier B.V. All rights reserved.

Automated summary

The discrepancy between Planck data and direct measurements of H0 and S8 has become one of the most intriguing puzzles in cosmology. The tension in H0 has reached 5σ in the context of the standard cosmology model. Exploring physics beyond the standard model is necessary to explain this issue.