Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:2209.08968

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

Ehsan Erfani Maharat, Mohsen Sarbishaei, Ali Ahanj

Published Sep 19, 2022• 0 citations
arXivHTMLPDF

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.

DOI
10.48550/arxiv.2209.08968

Related papers

Quantum theory has no problem consistently describing the use of itself

Guang Ping He

In a recent publication in Nature Communications by Frauchiger and Renner (Nat. Commun. 9, 3711 (2018)), a Gedankenexperiment was proposed, which was claimed to be able to lead to inconsistent conclusions with a self-referential use of quantum theory. Thus it seems to prove that quantum theory cannot consistently describe the use of itself. Shortly after, Chen and Zhang suggested an improvement (arXiv:1810.01080) which can made the explanation of the Gedankenexperiment become consistent. Here we show that from the viewpoint of any quantum interpretation theory which agrees that there is collapse of the wavefunction when being measured (e.g., the Copenhagen interpretation), the original conclusions of Frauchiger and Renner actually came from an incorrect description of some quantum states. With the correct description there will be no inconsistent results, even without modifying the original Gedankenexperiment.

•Oct 16, 2018•1 citation

How Quantum Mechanics can consistently describe the use of itself

Dustin Lazarovici, Mario Hubert

We discuss the no-go theorem of Frauchiger and Renner based on an "extended Wigner's friend" thought experiment which is supposed to show that any single-world interpretation of quantum mechanics leads to inconsistent predictions if it is applicable on all scales. We show that no such inconsistency occurs if one considers a complete description of the physical situation. We then discuss implications of the thought experiment that have not been clearly addressed in the original paper, including a tension between relativity and nonlocal effects predicted by quantum mechanics. Our discussion applies in particular to Bohmian mechanics.

Scientific Reports•Jan 24, 2019•113 citations

Consistency in the description of quantum measurement: Quantum theory can consistently describe the use of itself

Joseph M. Renes

Recent extended formulations of the Wigner's friend thought experiment throw the measurement problem of quantum mechanics into sharper relief. Here I respond to an invitation by Renner to provide a consistent and concrete set of rules for quantum mechanics which can avoid the apparent paradox formulated by Frauchiger and Renner [Nat. Comm. 9, 3711 (2018)]. I propose a slight addition to standard textbook quantum mechanics, in the form of two rules, which avoids the paradox. The first specifies when a given quantum dynamics can be interpreted as a measurement. Potentially any dynamics can, but doing so depends on the context of other performed operations. The second requires that a joint context be used to determine whether several different dynamical evolutions can all be interpreted as measurement. The paradox is then avoided because not every participant in the Frauchiger-Renner thought experiment regards the stated dynamical descriptions of the experiment as measurements.

arXiv:2107.02193•Jul 5, 2021•34 citations

On the paper "Quantum theory cannot consistently describe the use of itself"

Antonio Bernal

In the paper "Quantum theory cannot consistently describe the use of itself" by D. Frauchiger and R. Renner an atempt is made at proving a "no-go theorem" that states that either quantum theory cannot be universally applied, even to macroscopic systems, or some very intuitive properties concerning recursive reasoning and uniquenes of physical values must be false. In this paper, we give a concise description of the paper's result, and expose a detail in the proof.

arXiv:2106.07312•Jun 14, 2021•0 citations

How Single-World Quantum Mechanics is Consistent

Dustin Lazarovici, Mario Hubert

We discuss the no-go theorem of Frauchiger and Renner based on an extended Wigner's friend thought experiment which is supposed to show that any single-world interpretation of quantum mechanics leads to inconsistent predictions if it is applicable on all scales. We show that no such inconsistency occurs if one considers a complete description of the physical situation. We then discuss implications of the thought experiment that have not been clearly addressed in the original paper, including a tension between relativity and nonlocal effects predicted by quantum mechanics. Our discussion applies in particular to Bohmian mechanics.

•Sep 21, 2018•0 citations

Resolving Schrodinger's Cat, Wigner's Friend and Frauchiger-Renner's Paradoxes at a Single-Quantum Level

Nakka Gurappa

Schrodinger's cat and Wigner's friend paradoxes are analyzed using the `wave-particle non-dualistic interpretation of quantum mechanics at a single-quantum level' and are shown to be non-paradoxes within the quantum formalism. Then, the extended version of Wigner's friend thought experiment, proposed in a recent article titled, ``Quantum theory cannot consistently describe the use of itself '', Nature Communications {\bf 9}, 3711 (2018), by Frauchiger and Renner (FR) is considered. In quantum mechanics, it's well-known that, statistically observing a large number of identical quantum systems at some particular quantum state, which results in Born's probability, and merely inferring its presence in the same quantum state with the same probability yield distinct physical phenomena. If this fact is not taken care while interpreting any experimental outcomes, then FR type paradoxes pop up. ``What an astonishingly self-consistent the Quantum Theory is!' - is explicitly worked out in the case of FR gedankenexperiment. The present work shows the importance of single-quantum phenomenon for the non-paradoxical interpretation of statistically observed experimental outcomes.

•Sep 1, 2019•0 citations
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.
In a recent publication in Nature Communications by Frauchiger and Renner (Nat. Commun. 9, 3711 (2018)), a Gedankenexperiment was proposed, which was claimed to be able to lead to inconsistent conclusions with a self-referential use of quantum theory. Thus it seems to prove that quantum theory cannot consistently describe the use of itself. Shortly after, Chen and Zhang suggested an improvement (arXiv:1810.01080) which can made the explanation of the Gedankenexperiment become consistent. Here we show that from the viewpoint of any quantum interpretation theory which agrees that there is collapse of the wavefunction when being measured (e.g., the Copenhagen interpretation), the original conclusions of Frauchiger and Renner actually came from an incorrect description of some quantum states. With the correct description there will be no inconsistent results, even without modifying the original Gedankenexperiment.
We discuss the no-go theorem of Frauchiger and Renner based on an "extended Wigner's friend" thought experiment which is supposed to show that any single-world interpretation of quantum mechanics leads to inconsistent predictions if it is applicable on all scales. We show that no such inconsistency occurs if one considers a complete description of the physical situation. We then discuss implications of the thought experiment that have not been clearly addressed in the original paper, including a tension between relativity and nonlocal effects predicted by quantum mechanics. Our discussion applies in particular to Bohmian mechanics.
Recent extended formulations of the Wigner's friend thought experiment throw the measurement problem of quantum mechanics into sharper relief. Here I respond to an invitation by Renner to provide a consistent and concrete set of rules for quantum mechanics which can avoid the apparent paradox formulated by Frauchiger and Renner [Nat. Comm. 9, 3711 (2018)]. I propose a slight addition to standard textbook quantum mechanics, in the form of two rules, which avoids the paradox. The first specifies when a given quantum dynamics can be interpreted as a measurement. Potentially any dynamics can, but doing so depends on the context of other performed operations. The second requires that a joint context be used to determine whether several different dynamical evolutions can all be interpreted as measurement. The paradox is then avoided because not every participant in the Frauchiger-Renner thought experiment regards the stated dynamical descriptions of the experiment as measurements.
We discuss the no-go theorem of Frauchiger and Renner based on an extended Wigner's friend thought experiment which is supposed to show that any single-world interpretation of quantum mechanics leads to inconsistent predictions if it is applicable on all scales. We show that no such inconsistency occurs if one considers a complete description of the physical situation. We then discuss implications of the thought experiment that have not been clearly addressed in the original paper, including a tension between relativity and nonlocal effects predicted by quantum mechanics. Our discussion applies in particular to Bohmian mechanics.
Schrodinger's cat and Wigner's friend paradoxes are analyzed using the `wave-particle non-dualistic interpretation of quantum mechanics at a single-quantum level' and are shown to be non-paradoxes within the quantum formalism. Then, the extended version of Wigner's friend thought experiment, proposed in a recent article titled, ``Quantum theory cannot consistently describe the use of itself '', Nature Communications {\bf 9}, 3711 (2018), by Frauchiger and Renner (FR) is considered. In quantum mechanics, it's well-known that, statistically observing a large number of identical quantum systems at some particular quantum state, which results in Born's probability, and merely inferring its presence in the same quantum state with the same probability yield distinct physical phenomena. If this fact is not taken care while interpreting any experimental outcomes, then FR type paradoxes pop up. ``What an astonishingly self-consistent the Quantum Theory is!' - is explicitly worked out in the case of FR gedankenexperiment. The present work shows the importance of single-quantum phenomenon for the non-paradoxical interpretation of statistically observed experimental outcomes.