Testing Planck 2020 and DESI data on wCDM Models

This work delves into the dynamical dark energy models of the wCDM parameterisation that are defined by their equation of state by comparing different, well-known parameterisation models, in an attempt to lessen the tensions of {H_0} and {σ_8} by using the latest observational data. This research also tested the newer Planck likelihood and BAO data by comparing them to their predecessors. The data that was used were: the Cosmic Microwave Background (CMB) data of Planck 2018 and Planck 2020 data; Cosmic Chronometers (CC), a sample of Supernovae Type Ia; and Baryonic Acoustic Oscillations (BAO). A Bayesian analysis was performed to produce the results needed for the analysis. From the analyses, the best-fit values of the parameters show that almost all models are in favour of a phantom Universe. This study also showed that the new tested data constrained the models better than the previous ones, while also showing that the observation data supports the ΛCDM model over the dynamical dark energy models