First measurement of the Hubble constant from a combined weak-lensing and gravitational-wave standard siren analysis

Vol. 709
1. Letters to the Editor

First measurement of the Hubble constant from a combined weak-lensing and gravitational-wave standard siren analysis

The Hubble constant (H₀) quantifies the current rate of cosmic expansion. Although various probes have significantly reduced measurement uncertainty over the years, a conflict remains between results derived from different cosmic scales. New estimates based on alternative methods are therefore critical. In this Letter, the authors present the first combination of cosmological constraints from standard DESI results—incorporating density and shear fields from two-point correlation analyses—with gravitational-wave (GW) constraints from 142 binary coalescence events (sourced from the LVK transient catalog v4.0). Their analysis yields an H₀ estimate of 67.94 km/s/Mpc with 6.4% precision (potentially widening to ~10% when accounting for model uncertainties). Integrating GW data provides independent information for the standard cosmological model, helping to clarify the "Hubble tension." Furthermore, combining weak lensing and GW data improves constraints on matter density (Ω_m), serving as a pilot study for datasets that will only increase in quality and volume.