Joint Constraints on the Hubble Constant and Cosmic Baryon Density from Localized Fast Radio Bursts and DESI DR2 Baryon Acoustic Oscillations
Abstract
Fast radio bursts (FRBs) probe free-electron columns along cosmological sightlines through their dispersion measures (DMs), whereas baryon acoustic oscillations (BAO) constrain cosmic expansion geometry through acoustic distance ratios. In this work, we leverage their distinct physical sensitivities to simultaneously determine the Hubble constant (H0) and cosmic baryon density (Ωb) without external cosmic microwave background (CMB) or Big Bang nucleosynthesis (BBN) priors. Combining 120 localized FRBs and DESI DR2 BAO, we obtain H0=71.4+2.2−2.5 km s−1 Mpc−1 and Ωb=0.0503+0.0025−0.0021 in ΛCDM, corresponding to precisions of 3.3% and 4.6%, respectively. The inferred H0 is statistically consistent with both SH0ES and CMB, and Ωb agrees with the joint constraint from BBN and CMB. Adopting IllustrisTNG-based DM distributions and fixing the diffuse-gas baryon fraction tightens the constraint to H0=68.8±1.0 km s−1 Mpc−1, but lowers the central value toward the CMB-inferred value, identifying extragalactic DM modeling as the dominant systematic uncertainty. These results establish FRB-BAO complementarity as a new avenue for simultaneously constraining H0 and Ωb.
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BibTeX
@misc{zhang2026joint,
title = {{Joint Constraints on the Hubble Constant and Cosmic Baryon Density from Localized Fast Radio Bursts and DESI DR2 Baryon Acoustic Oscillations}},
author = {Ji-Guo Zhang and Tian-Nuo Li and Guo-Hong Du and Wan-Peng Sun and Jing-Fei Zhang and Xin Zhang},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.15536},
eprint = {2610.15536},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.15536},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - UNPB
TI - Joint Constraints on the Hubble Constant and Cosmic Baryon Density from Localized Fast Radio Bursts and DESI DR2 Baryon Acoustic Oscillations
AU - Ji-Guo Zhang
AU - Tian-Nuo Li
AU - Guo-Hong Du
AU - Wan-Peng Sun
AU - Jing-Fei Zhang
AU - Xin Zhang
PY - 2026
DA - 2026/10/11
PB - arXiv
DO - 10.48550/arxiv.2610.15536
UR - https://arxiv.org/abs/2610.15536
AB - Fast radio bursts (FRBs) probe free-electron columns along cosmological sightlines through their dispersion measures (DMs), whereas baryon acoustic oscillations (BAO) constrain cosmic expansion geometry through acoustic distance ratios. In this work, we leverage their distinct physical sensitivities to simultaneously determine the Hubble constant (H_0) and cosmic baryon density (Ω_b) without external cosmic microwave background (CMB) or Big Bang nucleosynthesis (BBN) priors. Combining 120 localized FRBs and DESI DR2 BAO, we obtain H_0=71.4^+2.2_−2.5 km s^−1 Mpc^−1 and Ω_b=0.0503^+0.0025_−0.0021 in ΛCDM, corresponding to precisions of 3.3% and 4.6%, respectively. The inferred H_0 is statistically consistent with both SH0ES and CMB, and Ω_b agrees with the joint constraint from BBN and CMB. Adopting IllustrisTNG-based DM distributions and fixing the diffuse-gas baryon fraction tightens the constraint to H_0=68.8±1.0 km s^−1 Mpc^−1, but lowers the central value toward the CMB-inferred value, identifying extragalactic DM modeling as the dominant systematic uncertainty. These results establish FRB-BAO complementarity as a new avenue for simultaneously constraining H_0 and Ω_b.
ER -