Cosmological parameter estimation for dynamical dark energy models with future fast radio burst observations

TL;DR

Future fast radio burst observations have the potential to significantly enhance cosmological parameter estimation, especially when combined with CMB and GW data, by breaking existing degeneracies and improving constraints on dark energy and baryon density.

Contribution

This study demonstrates the potential of future FRB data to improve cosmological constraints and break parameter degeneracies when combined with CMB and GW data.

Findings

FRB data can break parameter degeneracies in CMB data.

Combining FRB with CMB and GW improves constraints on dark energy.

10,000 FRB events could outperform BAO in parameter estimation.

Abstract

Fast radio bursts (FRBs) are a mysterious astrophysical phenomenon of bright pulses emitted at radio frequencies, and they are expected to be frequently detected in the future. The dispersion measures of FRBs are related to cosmological parameters, thus FRBs have the potential to be developed into a new cosmological probe if their data can be largely accumulated in the future. In this work, we study the capability of future FRB data to improve cosmological parameter estimation in two dynamical dark energy models. We find that the simulated FRB data can break the parameter degeneracies inherent in the current cosmic microwave background (CMB) data. Therefore, the combination of the CMB and FRB data can significantly improve the constraints on the Hubble constant and dark energy parameters, compared to those using CMB or FRB alone. If 10,000 FRB events with known redshifts are detected in the future, they would perform better than the baryon acoustic oscillation (BAO) data in breaking the parameter degeneracies inherent in the CMB data. We also find that the combination of FRB and gravitational-wave (GW) standard siren data provides an independent low-redshift probe to verify the results from the CMB and BAO data. For the data combination of CMB, GW, and FRB, it is found that the main contribution to the constraints comes from the CMB and GW data, but the inclusion of the FRB data still can evidently improve the constraint on the baryon density.