Spekkens, R. (2011). Formulating Quantum Theory as a Causally Neutral Theory of Bayesian Inference. Perimeter Institute for Theoretical Physics. https://pirsa.org/11110114
MLA
Spekkens, Robert. Formulating Quantum Theory as a Causally Neutral Theory of Bayesian Inference. Perimeter Institute for Theoretical Physics, Nov. 08, 2011, https://pirsa.org/11110114
BibTex
@misc{ scivideos_PIRSA:11110114,
doi = {10.48660/11110114},
url = {https://pirsa.org/11110114},
author = {Spekkens, Robert},
keywords = {Quantum Foundations},
language = {en},
title = {Formulating Quantum Theory as a Causally Neutral Theory of Bayesian Inference},
publisher = {Perimeter Institute for Theoretical Physics},
year = {2011},
month = {nov},
note = {PIRSA:11110114 see, \url{https://scivideos.org/index.php/pirsa/11110114}}
}
Quantum theory can be thought of as a noncommutative generalization of Bayesian probability theory, but for the analogy to be convincing, it should be possible to describe inferences among quantum systems in a manner that is independent of the causal relationship between those systems. In particular, it should be possible to unify the treatment of two kinds of inferences: (i) from beliefs about one system to beliefs about another, for instance, in the Einstein-Podolsky-Rosen or "quantum steering" phenomenon, and (ii) from beliefs about a system at one time to beliefs about that same system at another time, for instance, in predictions or retrodictions about a system undergoing dynamical evolution or undergoing a measurement. I will present a formalism that achieves such a unification by making use of "conditional quantum states", a noncommutative generalization of conditional probabilities. I argue for causal neutrality by drawing a comparison with a classical statistical theory with an epistemic restriction. (Joint work with Matthew Leifer).