Investigating the wCDM model with latest DESI BAO observations

Abstract In this study, we explore the impact of various combinations of CMB-independent datasets, including the recent DESI BAO measurements, on the equation of state (EoS) of dark energy and other cosmological parameters within the framework of the dynamical dark energy model (w CDM). Assuming a constant EoS parameter for dark energy, we derive constraints on the free parameters of the model using observational datasets such as DESI BAO, BBN, Observational Hubble Data (OHD), and Pantheon Plus (SN ^+ +) and SH0ES. Our analysis examines the deviations of the w CDM model from the standard Λ CDM scenario and assesses its implications for cosmological tensions, particularly the H₀ H 0 tension km~ s^-1~ Mpc^-1 km s - 1 Mpc - 1. We find that the combination of DESI BAO + BBN + OHD + SN ^+ + (DESI BAO + BBN + OHD + SN ^+ + and SH0ES) datasets provides constraints on w₃₄0, w de 0, suggesting a possible deviation from the cosmological constant scenario at a significance level of 1. 6 1. 6 σ (1. 4), (1. 4 σ), respectively. Furthermore, we observe an inverse correlation between w ₃₄₀ w de0 and H₀, H 0, which highlights the role of dark energy dynamics in resolving the tension H₀ H 0 by approximately 2. 1 (0. 8) 2. 1 σ (0. 8 σ) from DESI BAO + BBN + OHD (DESI BAO + BBN + OHD + SN ^+ + and SH0ES) datasets, respectively. Our findings offer valuable insights into the nature of dark energy and its influence on the cosmic expansion history, with implications for future observational efforts. We utilize the Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC) to evaluate our model’s performance. The results indicate that the w CDM model demonstrates superior effectiveness.