SIMBAD references

The dispersion measure-redshift relation of fast radio bursts (FRBs) provides a valuable cosmological probe for constraining the Hubble constant, offering an independent measurement that could help resolve the ongoing Hubble tension. In this paper, we begin with a sample of 117 localized FRBs and use 95 of them to constrain H₀ to $71.2{8}_{-2.08}^{+1.90}$ km s^–1 Mpc^–1 within the standard Lambda cold dark matter model. The resulting statistical uncertainty is below 2.8%, improving previous FRB-based measurements and highlighting the promise of larger future samples. Beyond statistical improvements, we note that different parameter choices have been adopted in previous studies and some results show discrepancies in H₀. To address this issue, we perform a systematic assessment of modeling uncertainties that can affect the inferred value of H₀, including models of the Galactic electron density, the contribution of the Galactic halo, outliers such as FRB 20190520B located in extreme environments, and the other parameter selections. We also discuss possible approaches to mitigate these sources of uncertainty, emphasizing both the challenges and prospects of using FRBs as reliable cosmological tools.