Prospects of strongly lensed repeating fast radio bursts: Complementary constraints on dark energy evolution

Fast radio bursts (FRBs) are highly dispersed and probably extragalactic radio flashes with millisecond duration. Recently, the Canadian Hydrogen Intensity Mapping Experiment (using the CHIME/FRB instrument) has reported detections of 13 FRBs during a pre-commissioning phase. It is more exciting that one of the 13 FRBs is a second source of repeaters which suggests that CHIME/FRB and other wide-field sensitive radio telescopes will find a substantial population of repeating FRBs. We have proposed strongly lensed repeating FRBs as a precision cosmological probe, e.g., constraining the Hubble constant and model independently estimating the cosmic curvature. Here, we study complementary constraints on the equation of state of dark energy from strongly lensed FRBs to currently available popular probes. It is found that, in the framework of Chevalier-Polarski-Linder parametrization, adding time delay measurement of 30 strongly lensed FRB systems to cosmic microwave background radiation and type Ia supernovae can improve the dark energy figure of merit by a factor 2. In the precision cosmology era, this improvement is of great significance for studying the nature of dark energy.

Figure 1

Redshift distribution of FRBs detected by different instruments.

Figure 2

Marginalized PDFs and the 68%, 95% confidence contours of the dark energy parameters $w_0$ and $w_a$, 30 lensed FRB systems plus SNe Ia and CMB are considered.

Figure 3

Marginalized PDFs and the 68%, 95% confidence contours of the dark energy parameters $w_0$ and $w_a$, 100 lensed FRB systems plus SNe Ia and CMB are considered.

Figure 4

The FoM of constraint on the dark energy equation of state from currently available popular probes (SNe $\mathrm{Ia}+\mathrm{CMB}$) plus different number of time delay measurement of strongly lensed FRB systems.