Understanding sequential measurements in psi-epistemic ontological models

quantum foundations;quantum physics;interpretations;ontological models

Ruebeck, Joshuaadvisor:Emerson, Joseph ; affiliation1:Faculty of Science ; Emerson, Joseph ;

University of Waterloo

关键词: ontological models;    Master Thesis;    quantum foundations;    interpretations;    quantum physics;   

Others  :  https://uwspace.uwaterloo.ca/bitstream/10012/14845/3/Ruebeck_Joshua.pdf

瑞士|英语

来源: UWSPACE Waterloo Institutional Repository

【 摘 要 】

Since the famous debates of Einstein & Bohr, physicists have argued about the nature of the quantum state. Is it best thought of as describing the-way-things-are out there in the world, or merely as a description of our knowledge of such things? In more recent years, this has been termed the ψ-epistemic/ψ-ontic debate, and that distinction has been given a mathematical definition within the ontological models formalism. This formalism is a framework for describing a large class of interpretations of quantum mechanics. Here we show that consideration of sequential measurements, and the fact that the quantum state changes during measurements, has been a neglected topic in this area as it places nontrivial restrictions on the structure of ψ-epistemic ontological models.We do this by finding a general restriction on the structure of ψ-epistemic models, although not one that is strong enough to rule them out categorically. We then apply this restriction to all of the known examples of ψ-epistemic ontological models and show that they can’t represent sequential measurements. We also present a new version of the ontological models formalism, based on hidden Markov models, which we develop briefly and describe how it may be useful for either proving a no-go theorem (i.e. 'ψ-epistemic models can’t exist’) or for learning more about the structure of ψ-epistemic models and how to construct them.