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The Local Distance Network: A community consensus report on the measurement of the Hubble constant at ∼1% precision | Astronomy & Astrophysics (A&A)

Astronomy & Astrophysics (A&A) is an international journal which publishes papers on all aspects of astronomy and astrophysics

The Stochastic Siren: Astrophysical Gravitational-Wave Background Measurements of the Hubble Constant

We report the first measurement of the Hubble constant $H_0$ using the stochastic gravitational-wave background arising from binary black hole mergers. This astrophysical background is sensitive to the expansion history of the Universe and thus can be used for cosmological parameter inference independently of not only electromagnetic methods, but also gravitational-wave standard siren approaches. We describe the background's cosmological dependence and show how it can be used as a ``stochastic siren'' to measure $H_0$. By analyzing existing resolved binary black hole mergers and the current non-detection of the background, we find that $H_0$ can be measured more accurately relative to using resolved mergers alone. We also note that the stochastic siren may serve a unique role in the Hubble tension in that the lower bound of the $H_0$ measurement would progressively increase with continued non-detection of the background.

New Method Uses Gravitational Waves to Improve Measurements of the Universe’s Expansion

Astronomers have long known that the universe is expanding, but the exact rate of expansion, measured by the Hubble constant, remains a mystery. Multiple methods used to calculate this constant have…

Measuring the expansion of the universe with cosmic fireworks

That the universe is expanding has been known for almost a hundred years now, but how fast? The exact rate of that expansion remains hotly debated,…

Prof. Wendy Freedman recognized with 2026 Franklin Institute Award in Physics

Pioneering cosmologist honored for landmark measurements of the Hubble Constant