Quantum theory can consistently describe the use of itself in Frauchiger-Renner's Gedankenexperiment

TL;DR

This paper challenges the validity of Frauchiger and Renner's no-go theorem by analyzing their proof approach, proposing a corrected quantum state representation, and demonstrating a fallacy in their argument, ultimately questioning the theorem's validity.

Contribution

It provides a critique of the Frauchiger-Renner proof, introduces a corrected quantum state formulation, and explores potential modifications to validate the no-go theorem.

Findings

Identified a fallacy in the original proof of the no-go theorem

Proposed a correct quantum state representation for similar thought experiments

Showed that the original proof's invalidity questions the theorem's conclusions

Abstract

Theoretical physics has faced many challenges since the advent of quantum mechanics. Recently, Frauchiger and Renner have presented a no-go theorem, which makes quantum mechanics more controversial. However, from our perspective, the process of proving appears questionable. Therefore, we discuss the validity of their proof approach in this letter. Here, we propose a simple thought experiment that clarifies how correctly the attributed quantum state can be written in problems similar to Frauchiger and Renner's Gedankenexperiment. In the next step, with the help of the correct form of the quantum state, it is demonstrated that a fallacy occurred in the proof of the no-go theorem, which means it cannot be valid because of the wrong proof. Ultimately, getting help from Hardy's paradox, we investigate whether there is an approach to modify their proof in order to lend the no-go theorem validity.