2025/09/25 by Tonghua Liu, Shuo Cao, Liu, Tonghua +3
Physics and Astronomy · #Astronomy and Astrophysical Research #Cosmology and Gravitation Theories #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #Scientific Research and Discoveries
paper · pdf · doi:10.48550/arxiv.2509.20898
openalex publication_date 2025/09/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present a determination of the Hubble constant (H0) using the latest observational data from multiple cosmological probes, providing an independent geometric calibration of the SN Ia distance scale. By combining baryon acoustic oscillation (BAO) measurements from the second data release of the Dark Energy Spectroscopic Instrument (DESI DR2), cosmic chronometer H(z) data, and the Pantheon Plus Type Ia supernova (SN Ia) sample, we reconstruct the cosmic expansion history through Gaussian process regression without assuming a specific cosmological model. Our analysis fully incorporates the complete covariance structure and yields H0 constraints at five distinct redshifts: 65.72 ± 1.99 (z=0.51), 67.78 ± 1.75 (z=0.706), 70.74 ± 1.39 (z=0.934), 71.04 ± 1.93 (z=1.321), and 68.37 ± 3.95~\mathrmkm~s-1~Mpc-1 (z=1.484). The Bayesian combination of these measurements gives H0 = 69.29 ± 0.81~\mathrmkm~s-1~Mpc-1 with 1.2% precision, which occupies an intermediate position between the Planck CMB result and the SH0ES local measurement. While we observe a non-monotonic pattern in H0 values across redshifts, statistical tests show this apparent evolution is not significant (p = 0.208). Our approach delivers independent constraints at multiple redshifts, enabling investigation of potential redshift-dependent systematic effects in the Hubble tension. The results demonstrate that an independent geometric method yields an H0 value consistent with the intermediate range of current measurements, providing a crucial cross-check of distance ladder determinations.