SIMBAD references

The Hubble constant (H₀) is one of the most important parameters in the standard ΛCDM model. The measurements given by the main two methods show a gap larger than 4σ, which is known as Hubble tension. Fast radio bursts (FRBs) are extragalactic pulses with durations of milliseconds. They can be used as cosmological probes. We constrain H₀ using localized and nonlocalized FRBs. We first used 108 localized FRBs to constrain H₀ using the probability distributions of DM_host and DM_IGM from the IllustrisTNG simulation. Then, we used a Monte Carlo sampling to calculate the pseudo-redshift distributions of 527 nonlocalized FRBs from CHIME observations. The 108 localized FRBs yield a constraint of $ H_0 = 69.40_{-1.97}^{+2.14} $ km s^–1 Mpc^–1, which lies between the early- and late-time values. The constraint of H₀ from nonlocalized FRBs yields $ H_0 = 68.81_{-0.68}^{+0.68} $ km s^–1 Mpc^–1. This result indicates that the uncertainty on the constraint of H₀ drops to ∼1% when the number of localized FRBs is increased to ∼500. These uncertainties only include the statistical error. The systematic errors are also discussed and play a dominant role in the current sample.