2025/10/24 by Capozziello, Salvatore, Chaudhary, Himanshu, Mustafa, G. +1 · 1 citation
#Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #High Energy Physics - Theory (hep-th)
paper · doi:10.48550/arxiv.2510.21976
We present a comprehensive analysis of the cosmological implications of the Dark Energy Spectroscopic Instrument (DESI) Data Release 2 (DR2) Lyman-α forest baryon acoustic oscillation (BAO) measurements, combined with complementary datasets DESI DR2 galaxy BAO, Type Ia supernova (Pantheon+, DES-SN5Y, and Union3), and compressed CMB likelihood. We test several dynamical dark energy models CPL, logarithmic, exponential, JBP, BA, and GEDE as well as ωCDM and non-flat extensions of the standard ΛCDM and ωCDM models. Using the Metropolis Hastings MCMC algorithm implemented in SimpleMC, we constrain the cosmological parameters of each model and evaluate the Bayesian evidence using MCEvidence to assess each model's performance relative to ΛCDM. Our results show that the inclusion of DESI DR2 Lyα data modestly enhances sensitivity to departures from ΛCDM. Our results show non-flat extensions remain consistent with spatial flatness (Ωk ≈ 0 within 1-2σ). Further, all redshift dependent dark energy models predict ω0 > -1, ωa < 0, and ω0 + ωa < -1, favor a dynamical dark energy scenario characterized by Quintom-B type, and we found that dynamical dark energy favors over the ΛCDM model ranging from 0.24-2.60σ, depending on the choice of model and corresponding combination of datasets. Bayesian evidence comparison favors the ωCDM model with moderate evidence over ΛCDM, whereas other parameterizations remain statistically inconclusive.