Anyone has proved the error rate of quantum computation is bounded by (less than) a constant rather than a function dependent on time and environment by quantum theory? For error rate and error correction of quantum computer, see Peter Shor.
I think assumptions to estimate error of quantum computation may be too simple to be practical or true, the quantum computation then has to be just a theoretical computational model.
Excuse me for posting such a question closely related to quantum theory, since physicists on physics.exchange have prohibited me from posting any suspicion about quantum computer, :D
UPDATE: Threshold theorem has to be proved with assumptions that is consistent to physics law, especially consistent to QFT, since there are fundamental obstacles to implementing scalable quantum computer; if we are unable to do so, I think we have to try to solve problem in another direction， the opposite direction, that is, trying to refute them (The assumptions infering scalable quantum computer) by physics theory.