Cosmology with fast radio bursts in the era of SKA

TL;DR

This paper forecasts how upcoming SKA observations of fast radio bursts can precisely measure dark energy, the Hubble constant, and baryon density, offering new independent cosmological constraints.

Contribution

It demonstrates that large samples of localized FRBs from SKA can outperform existing methods in constraining key cosmological parameters and resolve current tensions.

Findings

10^6 FRBs can tightly constrain dark energy parameters.

FRB data combined with gravitational waves can measure Hubble constant to sub-percent accuracy.

FRBs can determine baryon density with 0.1% precision.

Abstract

We present a forecast of the cosmological parameter estimation using fast radio bursts (FRBs) from the upcoming Square Kilometre Array (SKA), focusing on the issues of dark energy, the Hubble constant, and baryon density. We simulate $10^5$ and $10^6$ localized FRBs from a 10-year SKA observation, and find that: (i) using $10^6$ FRB data alone can tightly constrain dark-energy equation of state parameters better than CMB+BAO+SNe, providing an independent cosmological probe to explore dark energy; (ii) combining the FRB data with gravitational-wave standard siren data from 10-year observation with the Einstein Telescope, the Hubble constant can be constrained to a sub-percent level, serving as a powerful low-redshift probe; (iii) using $10^6$ FRB data can constrain the baryon density $\Omega_{\rm b}h$ to a precision of $\sim 0.1\%$. Our results indicate that SKA-era FRBs will provide precise cosmological measurements to shed light on both dark energy and the missing baryon problem, and help resolve the Hubble tension.