On the tenth anniversary of the first direct detection of a gravitational wave (GW150914), the LIGO-Virgo-KAGRA collaboration has announced a new important result. On January 14, 2025, the merger of two black holes was observed and the signal, called GW250114 and characterized by a high intensity, made it possible to verify that the final black hole behaves just as described by the model of a rotating black hole developed by the American physicist Roy Kerr. In addition, it was possible to confirm with much higher precision than in the past the so-called "Hawking's area law", according to which the merger of black holes always produces a black hole with an area greater than the sum of the areas of the initial black holes.

It is a very important result because it links the evolution of black holes to quantum phenomena that occur near the event horizon (the "surface" of black holes) and does so with a formalism reminiscent of thermodynamics and gives us a deeper understanding of these mysterious objects.

A group of physicists from the University of Trieste and the Trieste Section of the National Institute of Nuclear Physics (Edoardo Milotti, Giacomo Principe, Agata Trovato) also participates in this research, which also includes young researchers and PhD students (Davide Di Piero, Panagiotis Iosif, Leigh Smith, Giuseppe Troian).

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The article dedicated to GW250114 is featured on the cover of Physical Review Letters