Hubble parameter estimation via dark sirens with the LISA-Taiji network

Understand

The Hubble parameter is one of the central parameters in modern cosmology, which describes the present expansion rate of the universe.

• Their values inferred from the late-time observations are systematically higher than those from the early-time measurements by about $10\%$.
• To come to a robust conclusion, independent probes with accuracy at percent levels are crucial.
• Gravitational waves from compact binary coalescence events can be formulated into the standard siren approach to provide an independent Hubble parameter measurement.