Description
Quantum foundations has advanced significantly from Bell’s theorem to the strictly stronger Local-Friendliness (LF) no-go theorem [1], providing means to test assumptions about reality underlying physical theories and thereby unveiling nature’s counterintuitive behavior. The LF theorem’s proof relies on an extension incorporating Bell’s ideas and describing observers as quantum systems, motivated by the absence of compelling reasons to regard observations as anything other than physical processes and the expectation they admit a quantum description. Similarly, when such extensions hold and observers use the theory to make predictions, the Frauchiger–Renner (FR) paradox [2] reveals quantum mechanics’ paradoxical nature, with the resulting inconsistencies often linked to the measurement problem. A recent no-go theorem aims to refine FR-type paradoxes and establish connections with LF-like assumptions [3]. Within this framework, we show that combining assumptions of distinct ontological and epistemic character yield apparent contradictions not formally derivable, while weakened assumptions lead to resolutions consistent with interpretations such as Relational Quantum Mechanics (RQM), though their consequences are not always carried through consistently, often due to the subsequent introduction of incompatible ontological assumptions [3, 4]. Motivated by these results, future work will focus on identifying incompatible assumptions and misleading reasoning rules in fundamental and operational theories describing nature while yielding equivalent predictions for all agents.
[1] Kok-Wei Bong, Aníbal Utreras-Alarcón, Farzad Ghafari, Yeong-Cherng Liang, Nora Tischler, Eric G. Cavalcanti, Geoff J. Pryde, and Howard M. Wiseman. A strong no-go theorem on the Wigner’s friend paradox. 16(12):1199–1205.
[2] Daniela Frauchiger and Renato Renner. Quantum theory cannot consistently describe the use of itself. 9(1):3711.
[3] Laurens Walleghem, Rui Soares Barbosa, Matthew F. Pusey, and Stefan Weigert. A refined Frauchiger–Renner paradox based on strong contextuality. 10:2116.
[4] Eric G. Cavalcanti, Andrea Di Biagio, and Carlo Rovelli. On the consistency of relative facts. 13(4):55.
| I am the presenting author | Yes |
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