A path to precision cosmology: synergy between four promising late-universe cosmological probes

In the next decades, it is necessary to forge new late-universe cosmological probes precisely constrain Hubble constant and equation of state dark energy simultaneously. this work, we show that four typical probes, 21 cm intensity mapping (IM), fast radio burst (FRB), gravitational wave (GW) standard siren, strong lensing (SGL), are expected be forged into useful tools in solving tension exploring energy. We propose synergy them rather important cosmology. simulate IM, FRB, GW, SGL data based on hypothetical observations Hydrogen Intensity Real-time Analysis eXperiment (HIRAX), Square Kilometre Array (SKA), Einstein Telescope (ET), Large Synoptic Survey (LSST), respectively. find obviously different parameter degeneracy orientations constraints, so any combination can break degeneracies thus significantly improve constraint precision. The joint IM+FRB+GW+SGL provide errors $\sigma(\Omega_{\rm m})=0.0022$ $\sigma(H_0)=0.16\ \rm km\ s^{-1}\ Mpc^{-1}$ $\Lambda$CDM model, which meet precision cosmology, i.e., parameters better than 1%. addition, give $\sigma(w)=0.020$ $w$CDM $\sigma(w_0)=0.066$ $\sigma(w_a)=0.25$ $w_0w_a$CDM all constraints obtained by CMB+BAO+SN data. between has magnificent prospects.