The discovery of gravitational waves does not directly confirm the existence of gravitons. Gravitons are hypothetical particles that are postulated in certain theories, such as quantum field theory, to mediate the gravitational force, similar to how photons mediate the electromagnetic force.
Gravitational waves, on the other hand, are ripples in the fabric of spacetime caused by accelerating massive objects. Their existence was predicted by Albert Einstein's theory of general relativity, which describes gravity as the curvature of spacetime.
The detection of gravitational waves by the Laser Interferometer Gravitational-Wave Observatory (LIGO) in 2015 provided direct experimental evidence for the existence of these waves. This discovery confirmed a major prediction of Einstein's theory and opened up a new window for studying the universe.
However, the detection of gravitational waves does not directly confirm or disprove the existence of gravitons. Gravitons, if they exist, are hypothetical particles that are difficult to detect and require a complete theory of quantum gravity to be fully understood. The nature of gravity at the quantum level and the existence of gravitons are still active areas of research and remain to be experimentally confirmed.