Time Symmetric Quantum Theory Without Retrocausality? A Reply to Tim Maudlin

Abstract

In arXiv:1707.08641, Tim Maudlin claims to construct a counterexample to the result of Proc. Roy. Soc. A vol. 473, iss. 2202, 2017 (arXiv:1607.07871), in which it was shown that no realist model satisfying a certain notion of time-symmetry (in addition to three other assumptions) can reproduce the predictions of quantum theory without retrocausality (influences travelling backwards in time). In this comment, I explain why Maudlin's model is not a counterexample because it does not satisfy our time-symmetry assumption. I also explain why Maudlin's claim that one of the Lemmas we used in our proof is incorrect is wrong.