Strong constraints on models that explain the violation of Bell inequalities with hidden superluminal influences

TL;DR

This paper demonstrates that models explaining Bell inequality violations via hidden influences inevitably allow faster-than-light communication, challenging their viability as explanations for quantum correlations.

Contribution

It proves that all such hidden influence models necessarily permit superluminal signaling, ruling out their consistency with relativistic causality.

Findings

Hidden influence models cannot remain non-signaling

All models of this type imply faster-than-light communication

Quantum correlations cannot be fully explained by hidden influences

Abstract

We discuss models that attempt to provide an explanation for the violation of Bell inequalities at a distance in terms of hidden influences. These models reproduce the quantum correlations in most situations, but are restricted to produce local correlations in some configurations. The argument presented in [Bancal et al. Nature Physics 8, 867 (2012)] applies to all of these models, which can thus be proved to allow for faster-than-light communication. In other words, the signalling character of these models cannot remain hidden.