LARGE SCIENTIFIC PROJECT
Gravitational-Wave Astronomy
GRAVITATIONAL- WAVE ASTRONOMY: A CENTURY AFTER EINSTEIN, AND TEN YEARS AFTER THE FIRST DETECTION
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Matteo BARSUGLIA * and Eleonora CAPOCASA Université Paris Cité, CNRS, Astroparticule et Cosmologie, F-75013 Paris, France * matteo. barsuglia @ u-paris. fr
Since Einstein’ s 1916 prediction, gravitational-wave astronomy has evolved into a mature observational science. After early conceptual debates and bar-detector attempts, kilometer-scale laser interferometers LIGO achieved the first detection in 2015( GW150914), opening a new window for astronomy and enabling new tests of general relativity.
https:// doi. org / 10.1051 / photon / 202513448
This is an Open Access article distributed under the terms of the Creative Commons Attribution License( https:// creativecommons. org / licenses / by / 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
With Virgo joining in 2017, the LIGO and Virgo detectors and about 70 telescopes all around the world allowed the first multi-messenger event( GW170817), tightly constraining the speed of gravity, revealing r-process nucleosynthesis in a kilonova, and introducing“ standard siren” cosmology. By September 2025 the network, including now also the Japanese KAGRA, has reported nearly 300 candidate gravitational-wave sources( more than 200 published), enabling population studies of black-hole masses and spins, evidences of intermediate-mass black holes, and mixed systems. Here we review the historical developments, key technological milestones, and science highlights. On September 14, 2025, we have celebrated the tenth anniversary of the first detection of gravitational waves( the event called GW150914). Predicted by Albert Einstein in 1916 through the linearization of his general relativity field equations, these waves are oscillations of spacetime geometry that propagate at the speed of light and are emitted by the acceleration of asymmetric compact systems— such as a binary black hole system. Gravitational waves had a difficult beginning: Einstein himself, in his 1916 article, wrote that in all possible situations, their amplitude would be practically zero [ 1 ]. He was clearly aware of the challenge of deforming spacetime, a medium that is elastic yet extremely rigid, and even more, of making it vibrate. Of course,
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