Is general relativity required from quantum mechanics? One of the paradoxes against quantum mechanics was claimed by Einstein during one of the Solvay conferences: a paradox called the Einstein box also explained in this question. The solution proposed by Bohr contemplates the use of the gravitational redshift predicted by general relativity. In retrospect, does the confirmation of quantum mechanics imply the correctness of general relativity (as far as redshift predictions are concerned)? Or more generally: does quantum mechanics require general relativity for its consistency?

 A: Let's work with these summarises of Einstein's argument and Bohr's response, the latter repeating the former's assumptions about relativity and gravity. The response notes$$\color{red}{\Delta E}\color{blue}{\Delta t}=\color{red}{c^2\Delta m}\color{blue}{c^{-2}gt\Delta q}=\color{orange}{gt\Delta m}\Delta q\ge\color{orange}{\Delta p}\Delta q,$$where the red quantities are equal by special relativity, the blue quantities are equal by general relativity, and the orange quantities are equal by the acceleration $g$ Galileo knew about.
Does this thought experiment prove QM implies the coloured parts? No.
In an "I can get less $\Delta E\Delta t$ than Heisenberg said" argument, the explanation brings in extraneous-to-QM physics (in this case, the coloured parts). A counterargument uses that extra physics, which isn't a consequence of QM in either argument's view. If Einstein's argument works, QM is incompatible with the physics cited; if it doesn't, they may be compatible, but one needn't imply the other. If a third physicist doesn't grant these other ideas, that doesn't contradict QM; it just means they can't use them to work out what happens in the experiment.
A: There is a calculation of the vacuum energy in quantum mechanics which mismatches that of general relativity by roughly a hundred orders. Nevertheless, it predicts something qualitatively that is theorised in GR.
Moreover, Feynman in his lectures on gravitation attempts to derive GR from quantum mechanics. He actually gets quite far.
Finally, there is string theory - whichbis a quantum theory - and where as Witten points postdicts GR. Except thay this is not quite correct. It postdicts GR with higher curvature corrections.
All this is not quite finding that quantum theory requires gravity for its consistency. But one expects that in quantum gravity, that this will be the case. It's in my opinion, one of the hallmarks of a unified theory.
