The limits of quantum superposition: Should "Schrödinger's cat" and "Wigner's friend" be considered "miracle" narratives?

Suarez, Antoine

doi:10.48550/arxiv.1906.10524

Cited by 2 publications

(4 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…. Though Refs [19,20]. are both very relevant to QBist interests, neither of these get at the heart of the argument made here.…”

mentioning

confidence: 88%

See 1 more Smart Citation

Respecting One's Fellow: QBism's Analysis of Wigner's Friend

DeBrota¹,

Fuchs²,

Schack³

2020

Preprint

View full text Add to dashboard Cite

According to QBism, quantum states, unitary evolutions, and measurement operators are all understood as personal judgments of the agent using the formalism. Meanwhile, quantum measurement outcomes are understood as the personal experiences of the same agent. Wigner's conundrum of the friend, in which two agents ostensibly have different accounts of whether or not there is a measurement outcome, thus poses no paradox for QBism. Indeed the resolution of Wigner's original thought experiment was central to the development of QBist thinking. The focus of this paper concerns two very instructive modifications to Wigner's puzzle: One, a recent no-go theorem by Frauchiger and Renner [1], and the other a thought experiment by Baumann and Brukner [2]. We show that the paradoxical features emphasized in these works disappear once both friend and Wigner are understood as agents on an equal footing with regard to their individual uses of quantum theory. Wigner's action on his friend then becomes, from the friend's perspective, an action the friend takes on Wigner. Our analysis rests on a kind of quantum Copernican principle: When two agents take actions on each other, each agent has a dual role as a physical system for the other agent. No user of quantum theory is more privileged than any other. In contrast to the sentiment of Wigner's original paper, neither agent should be considered as in "suspended animation." In this light, QBism brings an entirely new perspective to understanding Wigner's friend thought experiments.

show abstract

“…. Though Refs [19,20]. are both very relevant to QBist interests, neither of these get at the heart of the argument made here.…”

mentioning

confidence: 88%

“…There are too many responses to these papers to cite here, but a sampling of those which attempt to analyse QBism's relation to the thought experiments can be found in Refs [12,13,14,15,16,17,18,19,20]…”

mentioning

confidence: 99%

Respecting One's Fellow: QBism's Analysis of Wigner's Friend

DeBrota¹,

Fuchs²,

Schack³

2020

Preprint

View full text Add to dashboard Cite

show abstract

“…There are too many responses to these papers to cite here, but a sampling of those which attempt to analyse QBism's relation to the thought experiments can be found in Refs [12][14][15][16][17][18][19][20]. Though Refs [19,20].…”

mentioning

confidence: 99%

“…[13][14][15][16][17][18][19][20]. Though Refs [19,20]. are both very relevant to QBist interests, neither of these get at the heart of the argument made here.…”

mentioning

confidence: 99%

Respecting One’s Fellow: QBism’s Analysis of Wigner’s Friend

2020

View full text Add to dashboard Cite

According to QBism, quantum states, unitary evolutions, and measurement operators are all understood as personal judgments of the agent using the formalism. Meanwhile, quantum measurement outcomes are understood as the personal experiences of the same agent. Wigner's conundrum of the friend, in which two agents ostensibly have different accounts of whether or not there is a measurement outcome, thus poses no paradox for QBism. Indeed the resolution of Wigner's original thought experiment was central to the development of QBist thinking. The focus of this paper concerns two very instructive modifications to Wigner's puzzle: One, a recent no-go theorem by Frauchiger and Renner (Nat Commun 9:3711, 2018), and the other a thought experiment by Baumann and Brukner (Quantum, Probability, Logic: The Work and Influence of Itamar Pitowsky, Springer, Cham, 2020). We show that the paradoxical features emphasized in these works disappear once both friend and Wigner are understood as agents on an equal footing with regard to their individual uses of quantum theory. Wigner's action on his friend then becomes, from the friend's perspective, an action the friend takes on Wigner. Our analysis rests on a kind of quantum Copernican principle: When two agents take actions on each other, each agent has a dual role as a physical system for the other agent. No user of quantum theory is more privileged than any other. In contrast to the sentiment of Wigner's original paper, neither agent should be considered as in "suspended animation." In this light, QBism brings an entirely new perspective to understanding Wigner's friend thought experiments.

show abstract

The limits of quantum superposition: Should "Schrödinger's cat" and "Wigner's friend" be considered "miracle" narratives?

Cited by 2 publications

References 17 publications

Respecting One's Fellow: QBism's Analysis of Wigner's Friend

Respecting One's Fellow: QBism's Analysis of Wigner's Friend

Respecting One’s Fellow: QBism’s Analysis of Wigner’s Friend

Contact Info

Product

Resources

About