The expansion rate of the Universe — the Hubble constant — is key to the age and fate of the cosmos. The 'peak siren' method compared distances from galaxy light and gravitational waves. A match was found with 5.9 sigma confidence: H₀ = 67 km/s/Mpc. This is a new way to measure without relying on tr
arXiv:2512.15380 · 2025-12-17