Gravitational Waves Propagate at Light Speed
Einstein's wave analysis showed that physical gravitational disturbances in the relativistic theory propagate through empty space at the speed of light.
Albert Einstein · Event
Einstein's wave analysis showed that physical gravitational disturbances in the relativistic theory propagate through empty space at the speed of light.

Einstein's wave analysis showed that physical gravitational disturbances in the relativistic theory propagate through empty space at the speed of light.