A simple proof of Bell's inequality

Abstract

Bell's theorem is a fundamental result in quantum mechanics: it discriminates between quantum mechanics and all theories where probabilities in measurement results arise from the ignorance of pre-existing local properties. We give an extremely simple proof of Bell's inequality: a single figure suffices. This simplicity may be useful in the unending debate of what exactly the Bell inequality means, since the hypothesis at the basis of the proof become extremely transparent. It is also a useful didactic tool, as the Bell inequality can be explained in a single intuitive lecture.

Version accepted for publication on American Journal of Physics. Appendix B added, along with various clarifications on the nomenclature

References in corpus (3)

• Hidden Variables and the Two Theorems of John Bell
• Bell violation with entangled photons, free of the fair-sampling assumption
• On a recent proof of nonlocality without inequalities

Cited by in corpus (5)

• The Measurement Problem: Decoherence and Convivial Solipsism
• Entanglement loss in molecular quantum-dot qubits due to interaction with the environment
• The Degree of Quantum Contextuality in terms of Concurrence for the KCBS Scenario
• Ghostly action at a distance: a non-technical explanation of the Bell inequality
• Inequality-free proof of Bell's theorem