>>11205576he was from the english school of relativists but learned QFT well enough to do fancy QFT calculations in curved spacetime. like he got the black hole temperature. most of his contemporary QFT experts didn’t think at all about GR and curved backgrounds, and even when they did they hit problems and gave up, and most relativists knew jack shit about QFT, but hawking managed to git gud at relativity and combine it with decent competency at QFT and found a very special case where you could successfully do QFT in a curved spacetime.
beyond that he was very knowledgeable about black holes, cosmology, and supergravity. he and penrose formulated some important theorems in GR relevant to black holes and cosmology. he also pointed out the BH information paradox which stimulated a lot of stuff in string theory, and string theorists like Stroninger and Vafa were celebrated for reproducing the BH temperature /entropy stuff that he and Bekenstein did. also i think his support for 11D supergravity provided inspiration to Witten when he was working out M theory
