2025/10/16 by Wang, Yi-Ying, Li, Yin-Jie, Fan, Yi-Zhong · 2 citations
#Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #High Energy Astrophysical Phenomena (astro-ph.HE)
paper · doi:10.48550/arxiv.2510.14390
Hubble constant tension, together with the recent indications of dynamical dark energy proposed from the Dark Energy Spectroscopic Instrument (DESI) baryon acoustic oscillation (BAO) measurements, poses significant challenges to the standard cosmological model. In this work, we perform a model-independent reconstruction of the dark-energy equation of state w(z), jointly with an evolving Hubble constant H0(z). Using the DESI DR2 data combined with multiple type Ia supernova samples, we find that w(z) varies with redshift and exhibits two potential phantom crossings at z∼0.5 and z∼1.5. Meanwhile, H0 decreases continually from local to high redshift, alleviating the Hubble constant tension effectively. The joint w(z)-H0(z) model is strongly favored over the wCDM (ΛCDM) framework, with a logarithmic Bayes factor ln \boldsymbol\mathcal B= 5.04~(8.53). Across various prior assumptions and dataset combinations, we obtain consistent, data-driven reconstructions of both w(z) and H0(z). Future BAO measurements from Euclid and next-generation CMB experiments will provide critical tests of these results and bring deeper insights into the nature of dark energy and the evolution of cosmic expansion.