Probability in many-world theories


Araujo, M. (2019). Probability in many-world theories. Perimeter Institute. https://pirsa.org/19040047


Araujo, Mateus. Probability in many-world theories. Perimeter Institute, Apr. 16, 2019, https://pirsa.org/19040047


          @misc{ pirsa_19040047,
            doi = {},
            url = {https://pirsa.org/19040047},
            author = {Araujo, Mateus},
            keywords = {Quantum Foundations},
            language = {en},
            title = { Probability in many-world theories},
            publisher = {Perimeter Institute},
            year = {2019},
            month = {apr},
            note = {PIRSA:19040047 see, \url{https://pirsa.org}}


A common criticism directed against many-world theories is that, being deterministic, they cannot make sense of probability. I argue that, on the contrary, deterministic theories with branching provide us the only known coherent definition of objective probability. I illustrate this argument with a toy many-worlds theory known as Kent's universe, and discuss its limitations when applied to the usual Many-Worlds interpretation of quantum mechanics.

I'll also argue that subjective probabilities are unproblematic in the many-worlds setting by showing how the usual decision-theoretical axioms apply there, and finish by showing that together with a proper definition of measurement they suffice to derive the Born rule.