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Related papers: Temporal nonlocality from indefinite causal orders

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The aim of this paper is to give a sharp definition of Bell's notion of local causality. To this end, first we unfold a framework, called local physical theory, integrating probabilistic and spatiotemporal concepts. Formulating local…

Quantum Physics · Physics 2015-06-22 G. Hofer-Szabó , P. Vecsernyés

Entanglement and its consequences - in particular the violation of Bell inequalities, which defies our concepts of realism and locality - have been proven to play key roles in Nature by many experiments for various quantum systems.…

Quantum mechanics allows for coherent control over the order in which different processes take place on a target system, giving rise to a new feature known as indefinite causal order. Indefinite causal order provides a resource for quantum…

Bell's theorem has been widely argued to show that some of the predictions of quantum mechanics which are obtained by applying the {\it Born's rule} to a class of {\it entangled states}, are {\it not} compatible with {\it any} local-causal…

Quantum Physics · Physics 2014-04-08 Agung Budiyono

Quantum theory predicts and experiments confirm that nature can produce correlations between distant events that are nonlocal in the sense of violating a Bell inequality. Nevertheless, Bell's strong sentence {\it Correlations cry out for…

Bell's theorem is a no-go theorem stating that quantum mechanics cannot be reproduced by a physical theory based on realism, freedom to choose experimental settings and two locality conditions: setting (SI) and outcome (OI) independence. We…

Quantum Physics · Physics 2015-05-13 M. Pawlowski , J. Kofler , T. Paterek , M. Seevinck , C. Brukner

For a system composed of two particles Bell's theorem asserts that averages of physical quantities determined from local variables must conform to a family of inequalities. In this work we show that a classical model containing a local…

Quantum Physics · Physics 2008-06-22 A. Matzkin

Non-local correlations are usually understood through the outcomes of alternative measurements (on two or more parts of a system) that cannot altogether actually be carried out in an experiment. Indeed, a joint input/output -- e.g.,…

Quantum Physics · Physics 2015-11-11 Stefan Wolf

There are two powerful arguments against the possibility of extending quantum mechanics, the violation of Bell inequalities and the Kochen-Specker theorem, but the connection between the two remains confused. Following the distinctive…

Quantum Physics · Physics 2025-01-08 Jianqi Sheng , Dongkai Zhang , Lixiang Chen

In a Bell test, the set of observed probability distributions complying with the principle of local realism is fully characterized by Bell inequalities. Quantum theory allows for a violation of these inequalities, which is famously regarded…

Quantum Physics · Physics 2022-06-01 Mariami Gachechiladze , Bartłomiej Bąk , Marcin Pawłowski , Nikolai Miklin

A standard approach in the foundations of quantum mechanics studies local realism and hidden variables models exclusively in terms of violations of Bell-like inequalities. Thus quantum nonlocality is tied to the celebrated no-go theorems,…

Quantum Physics · Physics 2007-05-23 James D. Malley , Arthur Fine

It is one of the most remarkable features of quantum physics that measurements on spatially separated systems cannot always be described by a locally causal theory. In such a theory, the outcomes of local measurements are determined in…

Quantum Physics · Physics 2016-09-08 Yeong-Cherng Liang

I define a notion of local causality LOC closely modelled on the Bell principle, construed as the condition that single case probabilities cannot be modified by actions at spacelike separation. The new principle, like that of Bell, forces…

Quantum Physics · Physics 2025-12-02 Simon Saunders

By taking into account that all real measurements are performed successively, during time, it is concluded that the violation of the Bell's inequalities in the Nature does not refute (even in an ideally perfect experiment) the theories…

Quantum Physics · Physics 2014-02-26 Alejandro A. Hnilo

Nonlocality is arguably one of the most fundamental and counterintuitive aspects of quantum theory. Nonlocal correlations could, however, be even more nonlocal than quantum theory allows, while still complying with basic physical principles…

Quantum Physics · Physics 2014-03-17 A. B. Sainz , T. Fritz , R. Augusiak , J. Bohr Brask , R. Chaves , A. Leverrier , A. Acín

Leggett-Garg inequalities (LGI) are constrains on certain combinations of temporal correlations obtained by measuring one and the same system at two different instants of time. The usual derivations of LGI assume \emph {macroscopic realism…

Quantum Physics · Physics 2014-06-24 Shiladitya Mal , Manik Banik , Sujit K Choudhary

Based on the new general framework for the probabilistic description of experiments, introduced in quant-ph/0305126, quant-ph/0312199, we analyze in mathematical terms the link between the validity of Bell-type inequalities under joint…

Quantum Physics · Physics 2007-05-23 Elena R. Loubenets

L. Vervoort [arxiv:1406.0901] claims to have found a model which "can violate the Bell inequality and reproduce the quantum statistics, even if it is based on local dynamics only". This claim is false. The proposed model contains global…

Quantum Physics · Physics 2017-01-27 I. Schmelzer

The no-signaling constraints state that the probability distribution of the outputs of any subset of parties is independent of the inputs of the complementary set; here we re-examine these to see how they arise from relativistic causality.…

Quantum Physics · Physics 2019-04-30 Paweł Horodecki , Ravishankar Ramanathan

It is widely accepted that the violation of Bell inequalities excludes local theories of the quantum realm. This paper presents a new derivation of the inequalities from non-trivial non-local theories and formulates a stronger Bell argument…

Quantum Physics · Physics 2018-07-06 Paul M. Näger