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Related papers: Bell's theorem without inequalities and without al…

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Non-locality without inequality is an elegant argument introduced by L. Hardy for two qubit systems, and later generalised to $n$ qubits, to establish contradiction of quantum theory with local realism. Interestingly, for $n=2$ this…

Quantum Physics · Physics 2015-05-19 Sibasish Ghosh , Shasanka Mohan Roy

We examine the problem of exhibiting Bell nonlocality for a two-qudit entangled pure state using a randomly chosen set of mutually unbiased bases (MUBs). Interestingly, even if we employ only two-setting Bell inequalities, we find a…

Quantum Physics · Physics 2022-07-19 Gelo Noel M. Tabia , Varun Satya Raj Bavana , Shih-Xian Yang , Yeong-Cherng Liang

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

Gisin's theorem assures that for any pure bipartite entangled state, there is violation of Bell-CHSH inequality revealing its contradiction with local realistic model. Whether, similar result holds for three-qubit pure entangled states,…

Quantum Physics · Physics 2013-05-29 Sujit K. Choudhary , Sibasish Ghosh , Guruprasad Kar , Ramij Rahaman

Violation of Bell inequality (or, Bell-type inequalities) by nonlocal correlations is justified by relaxation of at least one of the plausible physical constraints used to model such inequality. Based on this fact, in this letter we present…

Quantum Physics · Physics 2015-12-31 Biswajit Paul , Kaushiki Mukherjee , Debasis Sarkar

In contrast to the wide-spread opinion that any separable quantum state satisfies every classical probabilistic constraint, we present a simple example where a separable quantum state does not satisfy the original Bell inequality although…

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

Derivation of the full set of Bell inequalities involving correlation functions, for two parties, with binary observables, and N possible local settings is not as easy as it seemed. The proof of v1 is wrong. Additionaly one can find a…

Quantum Physics · Physics 2007-06-13 Piotr Badziag , Marek Zukowski

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

Bell's theorem is supposed to exclude all local hidden-variable models of quantum correlations. However, an explicit counterexample shows that a new class of local realistic models, based on generalized arithmetic and calculus, can exactly…

General Physics · Physics 2021-02-23 Marek Czachor

Hardy-type arguments manifest Bell nonlocality in one of the simplest possible ways. Except for demonstrating nonclassical signature of entangled states in question, they can also serve for device-independent self-testing of states, as…

Quantum Physics · Physics 2021-06-30 Ashutosh Rai , Matej Pivoluska , Martin Plesch , Souradeep Sasmal , Manik Banik , Sibasish Ghosh

We define a property called nondegeneracy for Bell inequalities, which describes the situation that in a Bell setting, if a Bell inequality and involved local measurements are chosen and fixed, any quantum state with a given dimension and…

Quantum Physics · Physics 2021-03-24 Zhaohui Wei , Lijinzhi Lin

Bell's theorem sets a boundary between the classical and quantum realms, by providing a strict proof of the existence of entangled quantum states with no classical counterpart. An experimental violation of Bell's inequality demands…

We give a simple proof of Bell's inequality in quantum mechanics which, in conjunction with experiments, demonstrates that the local hidden variables assumption is false. The proof sheds light on relationships between the notion of causal…

Applications · Statistics 2015-09-17 James M. Robins , Tyler J. VanderWeele , Richard D. Gill

Given a pair of isolated devices that accept random binary inputs and return binary outputs, a user can deduce from the observed data alone if the underlying mechanism can be explained classically. Bell's theorem further states that a…

Quantum Physics · Physics 2026-05-21 Kuntal Sengupta , Lewis Wooltorton

Bell's theorem states that quantum mechanical description on physical quantity cannot be fully explained by local realistic theories, and lays solid basis for various quantum information applications. Hardy's paradox is celebrated to be the…

Quantum Physics · Physics 2024-08-09 Si-Ran Zhao , Shuai Zhao , Hai-Hao Dong , Wen-Zhao Liu , Jing-Ling Chen , Kai Chen , Qiang Zhang , Jian-Wei Pan

The import of Bell's Theorem is elucidated. The theorem's proof is illustrated both heuristically and in mathematical detail in a pedagogical fashion. In the same fashion, it is shown that the proof is correct mathematically, but it doesn't…

Quantum Physics · Physics 2007-05-23 Anthony Rizzi

This paper is aimed to dissociate nonlocality from quantum theory. We demonstrate that the tests on violation of the Bell type inequalities are simply statistical tests of local incompatibility of observables. In fact, these are tests on…

Quantum Physics · Physics 2021-01-01 Andrei Khrennikov

The 1964 theorem of John Bell shows that no model that reproduces the predictions of quantum mechanics can simultaneously satisfy the assumptions of locality and determinism. On the other hand, the assumptions of \emph{signal locality} plus…

Quantum Physics · Physics 2012-10-25 Eric G. Cavalcanti , Howard M. Wiseman

Quantum correlations in Bell and prepare-and-measure experiments are central resources for probing nonclassicality and enabling device-based quantum information protocols. In the absence of shared public randomness (i.e., without run-to-run…

Quantum Physics · Physics 2026-04-21 Liang-Liang Sun , Xiang Zhou , Chengjie Zhang , Zizhu Wang , Yong-Shun Song , Sixia Yu

Some new temporal Bell inequalities are deduced under joint realism assumption, using some perfect correlation property. No locality condition is needed. When the measured system is a macroscopic system, joint realism assumption substitutes…

Quantum Physics · Physics 2007-05-23 Ramon Lapiedra