Hawking radiation is a theoretical prediction made by physicist Stephen Hawking in 1974. It arises from the combination of quantum mechanics and general relativity, which describes the behavior of gravity. Specifically, Hawking radiation is a consequence of quantum effects near the event horizon of a black hole.
In our current understanding of physics, quantum gravity is not yet fully realized. However, the existence of Hawking radiation does not depend on having a complete theory of quantum gravity. It is derived using quantum field theory in curved spacetime, which is a framework that combines quantum mechanics with general relativity on a semiclassical level.
The semiclassical approach treats gravity classically while incorporating quantum effects for other fields, such as particles and fields near black holes. It allows for the prediction of Hawking radiation based on the behavior of quantum fields in the curved spacetime surrounding a black hole's event horizon.
So, even if a complete theory of quantum gravity has not been established, the concept of Hawking radiation remains a significant theoretical prediction within the framework of semiclassical gravity.