Implications of Local Friendliness Violation for Quantum Causality

Cavalcanti, Eric G.; Wiseman, Howard Mark

doi:10.3390/e23080925

Cited by 16 publications

(19 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Like Bell's inequalities [23,24], these are derived in a theoryindependent way, and then shown to be violated by the predictions of quantum theory. If we do not reject (b) or (c), the universal validity of quantum theory implies that facts cannot all be observer independent 3 [28].…”

Section: B No-go Theorems For Non-relative Factsmentioning

confidence: 97%

Stable Facts, Relative Facts

Di Biagio,

Rovelli

2020

Preprint

View full text Add to dashboard Cite

We define and characterise two kinds of facts that play a role in quantum theory: stable and relative. We describe how stable facts emerge in a world of relative facts and then discuss the respective roles they play in connecting the theory and the world. The distinction between relative and stable facts resolves the difficulties pointed out by the no-go theorems of Frauchiger and Renner, Brukner, and Bong et. al.. Basing the ontology of the theory on relative facts clarifies the role of decoherence in bringing about the classical world and solves the apparent incompatibility between the 'linear evolution' and 'projection' postulates. I. FACTS IN QUANTUM THEORY

show abstract

Section: B No-go Theorems For Non-relative Factsmentioning

confidence: 97%

Stable Facts, Relative Facts

Di Biagio,

Rovelli

2020

Preprint

View full text Add to dashboard Cite

show abstract

“…One could then simply define λ as C, but that is also no good because, in that case, as with previous attempts, the reasons we have for assuming λ to be independent of the settings disappear. More generally, there are two issues with attempts (see also Cavalcanti and Wiseman (2021)) at deriving factorizability from the principle of local causality and the common cause principle. The first, as we just saw, is that he have no control over the scope and nature of the common cause C, so it cannot be assumed to be λ, nor to be independent of the settings.…”

Section: The Stanford Encyclopediamentioning

confidence: 99%

From locality to factorizability: a novel escape from Bell's theorem

Ciepielewski¹,

Okon²

2022

Preprint

View full text Add to dashboard Cite

While initial versions of Bell's theorem captured the notion of locality with the assumption of factorizability, in later presentations, Bell argued that factorizability could be derived from the more fundamental principle of local causality. Here we show that, contrary to what is commonly assumed, in order to derive factorizability from the principle of local causality, a non-trivial assumption, similar but strictly independent of settings independence, is required. Loosely speaking, such an extra assumption demands independence between the states of the measurement apparatuses. We conclude that it is possible to construct a model, satisfying both the principle of local causality and settings independence, but that, in virtue of violating this additional assumption-and thus factorizability-is able to break Bell's inequality.

show abstract

“…Moreover, these proposals build their results only employing correlations among the results of the superobservers. This group includes the "no-go theorem for observerindependent facts" in Brukner (2018), as well as the "Local Friendliness no-go theorem" in Bong et al (2020) (see also Cavalcanti and Wiseman (2021)). These theorems are the main subject of this assessment.…”

Section: Introductionmentioning

confidence: 99%

Reassessing the strength of a class of Wigner's friend no-go theorems

Okon¹

2022

Preprint

View full text Add to dashboard Cite

Two recent, prominent theorems-the "no-go theorem for observer-independent facts" and the "Local Friendliness no-go theorem"-employ so-called extended Wigner's friend scenarios to try to impose novel, non-trivial constraints on the possible nature of physical reality. While the former is argued to entail that there can be no theory in which the results of Wigner and his friend can both be considered objective, the latter is said to place on reality stronger constraints than the Bell and Kochen-Specker theorems. Here, I conduct a thorough analysis of these theorems and show that they suffer from a list of shortcomings that question their validity and limit their strength. I conclude that the "no-go theorem for observer-independent facts" and the "Local Friendliness no-go theorem" fail to impose significant constraints on the nature of physical reality.

show abstract

Implications of Local Friendliness Violation for Quantum Causality

Cited by 16 publications

References 41 publications

Stable Facts, Relative Facts

Stable Facts, Relative Facts

From locality to factorizability: a novel escape from Bell's theorem

Reassessing the strength of a class of Wigner's friend no-go theorems

Contact Info

Product

Resources

About