LIGO experiment confirmed one of the predictions of:

The Laser Interferometer Gravitational-Wave Observatory (LIGO) detected gravitational waves for the first time in 2015 (announced in 2016) from the merger of two black holes. The existence of gravitational waves had been predicted by Albert Einstein in 1916 as a consequence of his General Theory of Relativity. Hence, LIGO confirmed a key prediction of the General Theory of Relativity.