Uncorrelated Estimations of <i>H</i> ₀ Redshift Evolution from DESI Baryon Acoustic Oscillation Observations

Abstract

Abstract The Dark Energy Spectroscopic Instrument (DESI) collaboration recently released the first-year data of baryon acoustic oscillations (BAOs). Based on the five different tracers, the cosmological constraint shows a hint of deviation from the standard ΛCDM model. In this Letter, we combine the DESI BAOs with other cosmic probes to constrain the evolution of the Hubble constant as a function of redshift in the flat ΛCDM model. The nonparametric method is used to estimate the value of the Hubble constant at different redshift bins. The correlations among different bins are removed by diagonalizing the covariance matrix. The joint data sample demonstrates a decreasing trend of the Hubble constant with a significance of 6.4 σ , which can naturally resolve the Hubble tension. To avoid statistical effects caused by the binning methods, we tested three other different binning methods and also found a decreasing trend. It may be due to dynamical dark energy or modified gravity.