  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.
