Revealing Limitation in the Standard Cosmological Model: A Redshift-Dependent Hubble Constant from Fast Radio Bursts

A major issue in contemporary cosmology is the persistent discrepancy, known as the Hubble tension, between the Hubble constant (H₀) estimates from local measurements and those inferred from early-Universe observations under the standard $Λ$ cold dark matter ($Λ$CDM) paradigm. Recent advances have identified fast radio bursts (FRBs), a class of extragalactic phenomena observable at considerable redshifts, as a promising observational tool for probing late-time cosmology. In this study, we incorporate two complementary methodologies, machine learning algorithms and Bayesian analysis, on a set of localized FRBs to rigorously test the consistency of the $Λ$CDM model at late cosmic epochs. Our results reveal a statistically significant redshift-dependent variation of H₀, which contradicts the core postulate of $Λ$CDM. We further validate that the redshift dependency of H₀ can be removed within the more flexible framework of w₀wₐCDM model. These findings highlight that the redshift evolution of H₀ is not merely an artifact of the standard model but an indication of a deeper inadequacy in the $Λ$CDM model, supporting the need for a more flexible cosmological framework.