Relational Quantum Mechanics with Cross-Perspective Links Postulate: an Internally Inconsistent Scheme
Year: 2023
Type: preprint
Abstract: We discuss the status of relative facts - the central concept of Relational Quantum Mechanics (RQM) - in the context of the new amendment to RQM called cross-perspective links postulate. The new axiom states that by a proper measurement one learns the value of the relative outcome/fact earlier obtained by another observer-system. We discuss a Wigner-Friend-type scenario in which, without cross-perspective links postulate, relative facts have no predictive or causal power, whereas including cross-perspective links makes them effectively hidden variables, which causally determine outcomes of specific measurements. However, cross-perspective links axiom invalidates the other axiom of RQM, the one which states that in a Wigner-Friend scenario, RQM assigns an entangled state to the Friend and System after the unitary transformation of their interaction, despite the appearance of the relative fact for the Friend. This quantum mechanical state according to RQM properly describes the situation for Wigner. From this we show that RQM with cross-perspective links axiom is an internally inconsistent hidden variable theory and therefore cannot be treated as an interpretation of quantum mechanics in any sense.
Source: arXiv (Cornell University)
Authors: Markiewicz, Marcin, Żukowski, Marek
Institution: University of Gdańsk
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funder: Fundacja na rzecz Nauki Polskiej
Award: G7569305816
OpenAlex ID: W4389714150