Can quantum states be understood as Bayesian states of belief?

          @misc{ scivideos_PIRSA:18040116,
            doi = {10.48660/18040116},
            url = {https://pirsa.org/18040116},
            author = {Myrvold, Wayne},
            keywords = {Quantum Foundations},
            language = {en},
            title = {Can quantum states be understood as Bayesian states of belief?},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2018},
            month = {apr},
            note = {PIRSA:18040116 see, \url{https://scivideos.org/index.php/pirsa/18040116}}
          }
          

Abstract

In accordance with Betteridge's Law of Headlines, the answer to the question in the title is "no." I will argue that the usual norms of Bayesian inference lead the conclusion that quantum states are features of physical reality. The argument will involve both existing $\psi$-ontology results and extension of them that avoids the use of the Cartesian Product Assumption. As the usual norms of Bayesian inference lead to the conclusion of the reality of quantum state, rejecting it requires abandonment of virtually all of Bayesian information theory. This, I will argue, is unwarranted