Overview

• Published in Physical Review Letters, the LVK analysis of GW250114 provides the most precise confirmation to date that the total event-horizon area grows during a merger, upholding Hawking’s area theorem.
• The exceptionally strong signal—seen about four times more clearly than 2015’s GW150914 thanks to detector upgrades—allowed a clean separation of the post-merger ringdown.
• Ringdown measurements show the remnant behaves like a Kerr black hole, offering the most direct observational evidence so far for this cornerstone prediction of general relativity.
• Separately, researchers report the first full 3D measurement of a newborn black hole’s recoil from GW190412, finding a kick exceeding ~50 km/s in results published in Nature Astronomy.
• LIGO-India scientists contributed to the GW250114 analysis, with the Indian detector under construction toward ~2030 operations, as U.S. sites plan upgrades and face potential NSF budget cuts that could curtail observatory activity.