# Bell Nonlocality

@inproceedings{Brunner2019BellN, title={Bell Nonlocality}, author={Nicolas Brunner and Daniel Cavalcanti and Stefano Pironio and Valerio Scarani and Stephanie Wehner}, year={2019} }

Nonlocality was discovered by John Bell in 1964, in the context of the debates about quantum theory, but is a phenomenon that can be studied in its own right. Its observation proves that measurements are not revealing pre-determined values, falsifying the idea of “local hidden variables” suggested by Einstein and others. One is then forced to make some radical choice: either nature is intrinsically statistical and individual events are unspeakable, or our familiar space-time cannot be the…

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## References

SHOWING 1-10 OF 48 REFERENCES

Statistics, causality and Bell's theorem

- Philosophy
- 2014

It is argued that Bell�s theorem (and its experimental confirmation) should lead us to relinquish not locality, but realism, and Methodological and statistical issues in the design of quantum Randi challenges (QRC) are discussed.

Quantum non-locality and relativity

- Physics
- 1994

It is sometimes stated that composite quantum systems in entangled states are fundamentally ‘non-local’(i.e. a measurement on one component system can affect a spacelike separated system…

Experimental violation of a Bell's inequality with efficient detection

- PhysicsNature
- 2001

Here, correlations in the classical properties of massive entangled particles (9Be+ ions): these correlations violate a form of Bell's inequality, and the high detection efficiency of the apparatus eliminates the so-called ‘detection’ loophole.

Can Quantum-Mechanical Description of Physical Reality Be Considered Complete?

- Philosophy
- 1935

Consideration of the problem of making predictions concerning a system on the basis of measurements made on another system that had previously interacted with it leads to the result that one is led to conclude that the description of reality as given by a wave function is not complete.

What Bell did

- Physics
- 2014

On the 50th anniversary of Bell’s monumental 1964 paper, there is still widespread misunderstanding about exactly what Bell proved. This misunderstanding derives in turn from a failure to appreciate…

Loophole-free Bell inequality violation using electron spins separated by 1.3 kilometres

- PhysicsNature
- 2015

The data imply statistically significant rejection of the local-realist null hypothesis and could be used for testing less-conventional theories, and for implementing device-independent quantum-secure communication and randomness certification.

Cosmic Bell Test: Measurement Settings from Milky Way Stars.

- PhysicsPhysical review letters
- 2017

In tests with polarization-entangled photons, measurement settings were chosen using real-time observations of Milky Way stars while simultaneously ensuring locality, pushing back by ∼600 years the most recent time by which any local-realist influences could have engineered the observed Bell violation.

"All versus nothing" inseparability for two observers.

- PhysicsPhysical review letters
- 2001

A recent proof of Bell's theorem without inequalities is formulated as a Greenberger-Horne-Zeilinger-type proof involving just two observers, leading to a new state-independent proof of the Kochen-Specker theorem and provides a wider perspective on the relations between the major proofs of no hidden variables.

The two Bellʼs theorems of John Bell

- Philosophy
- 2014

Many of the heated arguments about the meaning of ‘Bellʼs theorem’ arise because this phrase can refer to two different theorems that John Bell proved, the first in 1964 and the second in 1976. His…

Algorithmic Pseudorandomness in Quantum Setups.

- Computer Science, PhysicsPhysical review letters
- 2016

This Letter presents a new loophole for Bell-like experiments: if some of the parties choose their measurements pseudorandomly, then the computational resources of the local model have to be limited in order to have a proper observation of nonlocality.