Is there any relationship between the Speed of gravitational waves and the Universe's "local" expansion rate? Speed of gravitational waves is supposed to be equal to the speed of light. Gravitational waves don't travel faster than light. But we can observe far galaxies moving away from us with high redshifts values that most people explain as the result of the creation of new space in-between us and the galaxy. We can call it the expansion rate. Other theories such as some kind of absorption exist. What sounds strange to me is that expansion rate can be faster than light, though not locally.