Contextual inferences, nonlocality, and the incompleteness of quantum mechanics

TL;DR

This paper explores the nonlocality in quantum mechanics, arguing that the quantum state is predictively incomplete and should be completed by including measurement context to reconcile nonlocality with relativity.

Contribution

It introduces a new perspective that quantum state incompleteness can be addressed by contextual measurement information, not hidden variables.

Findings

Quantum nonlocality arises from elementary locality and predictive incompleteness.

Quantum mechanics violates predictive completeness, enabling contextual inferences.

Completing the quantum state involves specifying measurement context, not hidden variables.

Abstract

It is known that "quantum non locality", leading to the violation of Bell's inequality and more generally of classical local realism, can be attributed to the conjunction of two properties, that we call here elementary locality and predictive completeness. Taking this point of view, we show again that quantum mechanics violates predictive completeness, allowing to make contextual inferences, which can in turn explain why quantum non locality does not contradict relativistic causality. But if the usual quantum state $\psi$ is predictively incomplete, how to complete it ? We give here a set of new arguments to show that $\psi$ should be completed indeed, not by looking for any "hidden variables", but rather by specifying the measurement context, which is required to define actual probabilities over a set of mutually exclusive physical events.