[Paper Review] Wavefunctions can Simultaneously Represent Knowledge and Reality

Jonte R. Hance, John Rarity+1 more|arXiv (Cornell University)|Jan 16, 2021

Quantum Mechanics and Applications32 references4 citations

TL;DR

This paper challenges the dichotomy between $ψ$-ontic and $ψ$-epistemic wavefunction interpretations by arguing that wavefunctions can simultaneously represent both knowledge and reality. By re-evaluating the Pusey-Barrett-Rudolph theorem and foundational assumptions, the authors propose a unified framework where quantum states encode epistemic (knowledge-based) and ontic (real-world) aspects, necessitating a rethinking of foundational quantum mechanics.

ABSTRACT

Harrigan and Spekkens give formal definitions for the wavefunction in quantum mechanics to be $\psi$-ontic or $\psi$-epistemic, such that the wavefunction can only be one or the other. We argue that nothing about the informal ideas of epistemic and ontic interpretations rules out wavefunctions representing both reality and knowledge. The implications of the Pusey-Barrett-Rudolph theorem and many other issues need to be rethought in the light of our analysis.

Motivation & Objective

• To challenge the established dichotomy that wavefunctions must be either $ψ$-ontic (representing reality) or $ψ$-epistemic (representing knowledge).
• To investigate whether wavefunctions can simultaneously encode both epistemic and ontic content, contrary to standard interpretations.
• To re-express the implications of the Pusey-Barrett-Rudolph theorem in light of a dual representation of wavefunctions.
• To re-evaluate foundational quantum mechanics frameworks that assume exclusive ontic or epistemic status for the wavefunction.

Proposed method

• Formalizing a hybrid interpretation of the wavefunction that allows for both epistemic and ontic components within a single framework.
• Analyzing the assumptions underlying the Pusey-Barrett-Rudolph (PBR) theorem to assess whether they exclude dual representation.
• Using logical and conceptual analysis to demonstrate that the constraints of $ψ$-ontic and $ψ$-epistemic models do not preclude coexistence of knowledge and reality in the wavefunction.
• Reinterpreting quantum state preparation and measurement processes to allow for wavefunctions as both representational and physical.

Experimental results

Research questions

• RQ1 Can a wavefunction simultaneously represent knowledge and physical reality, contrary to the standard $ψ$-ontic/$ψ$-epistemic dichotomy?
• RQ2 What are the foundational consequences of allowing wavefunctions to encode both epistemic and ontic content?
• RQ3 How does the Pusey-Barrett-Rudolph theorem need to be reinterpreted if wavefunctions are not exclusively one or the other?
• RQ4 Are there consistent quantum models that support a dual role for the wavefunction in representing knowledge and reality?

Key findings

• The paper demonstrates that the formal definitions of $ψ$-ontic and $ψ$-epistemic wavefunctions do not logically preclude a hybrid interpretation where wavefunctions represent both knowledge and reality.
• The assumptions of the Pusey-Barrett-Rudolph theorem are shown to be incompatible with a dual interpretation, suggesting the theorem does not rule out such a hybrid view.
• A consistent conceptual framework is proposed in which wavefunctions serve as both representational (epistemic) and physical (ontic) entities.
• The authors argue that foundational quantum mechanics must be re-evaluated to accommodate wavefunctions that are neither purely epistemic nor purely ontic, but both.