Gravitational-wave (GW) standard sirens have the potential to measure the Hubble constant $H_0$ in the local Universe independent of the distance ladder and thus offer unique insights into the Hubble tension. A key challenge with standard sirens is detecting their electromagnetic counterparts and therefore assigning redshifts to the measured distances. One promising way to proceed is to utilize GW dark sirens—events without an identified electromagnetic counterpart—and cross-correlate their angular distribution with that of galaxies. We present a quantitative study of how precisely the Hubble constant can be measured using tomographic cross-correlation between galaxies and GW sources. Overall, we find that the constraints on $H_0$ will be limited by the quality and quantity of GW data. We find that percent-level constraints on $H_0$ will primarily depend on achieving small distance uncertainties (${\sigma }_{d_L}=0.1d_L$), obtaining a large number of GW dark sirens ($\gtrsim 5000$) and accurate sky localization in the tomographic analysis.

Close

PrevNext

View figure in article

• Cosmological parameters
• Dark energy
• Gravitational waves
• Large scale structure of the Universe