Key Information

• Authors: Yi-Ying Wang, Shi-Jie Gao, Yi-Zhong Fan
• Journal: The Astrophysical Journal
• Year: 2025
• DOI: 10.3847/1538-4357/adade8
• NASA ADS: 2025ApJ…981….9W
• arXiv: 2501.09260

Abstract

Recent baryon acoustic oscillation (BAO) measurements from the Dark Energy Spectroscopic Instrument (DESI) collaboration, combined with the cosmic microwave background (CMB) and type Ia supernovae observations, suggest a preference for dynamical dark energy (DDE) with w₀ > -1 and w_a < 0. Given the cosmological origin of fast radio bursts (FRBs), the combination of their dispersion measures (DMs) and host galaxy redshifts makes localized FRBs a valuable tool for probing cosmology. Using an updated sample of 92 localized FRBs, along with DESI BAO, PlantheonPlus, and CMB data, we constrain the dark energy (DE) equation of state (EoS) under the Chevallier─Polarski─Linder parameterization. We find that even without incorporating CMB data, DDE remains preferred with and at a confidence level of ∼2.5σ. A joint analysis constrains these to be and , showing a discrepancy with ΛCDM at a ∼3.1σ level. Furthermore, using localized FRBs alone, we estimate the Hubble constant H₀ to be and , assuming the Galactic electron density models to be NE2001 and YMW16, respectively. Thus, accurate accounting of the Galactic DM is crucial for resolving the Hubble tension with FRBs. Future BAO measurements, next-generation CMB experiments, and more localized FRBs will further constrain the DE EoS and the cosmological parameters.