On Quantum Entanglement and Nonlocality

TL;DR

This paper revisits quantum entanglement and Bell inequalities, arguing that Bell tests reflect population dynamics rather than fundamental incompatibility, and confirms local causality in photon correlations.

Contribution

It challenges the traditional interpretation of Bell inequality violations, proposing they are related to population-level phenomena rather than local hidden variables.

Findings

Bell inequality holds at individual instances but not over populations

Bell tests can be explained by local causality without violating relativity

Photon correlations are consistent with local causes

Abstract

EPR showed that two particles emitted from a source can be entangled by a shared wavefunction where two non-commuting observables (position, momentum) can be simultaneously real, leading to a contradiction with quantum mechanics (two non-commuting variables can not be simultaneously real). John Bell derived an inequality where any local hidden variables prediction is bounded and quantum mechanics can violate the inequality. Bell tests on correlated photon pairs showed a clear violation of the Bell inequality and agreement with quantum mechanics. This study revealed that the Bell inequality holds at any individual instances in a given system but it does not hold over the entire population. The Bell inequality is not an incompatibility criterion for local hidden variables vs quantum mechanics rather it is a criterion for an individual nature vs population dynamics. The nonlocality prediction given by wavefunction is a system approximation and local causality (photon polarization) provides a complete description of the Bell tests. The paper concludes with great satisfaction that the measurement of two correlated photons at a distance was a local cause (photon-filter interaction did not violate the special theory of relativity).