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arXiv · 1606.04274

GHZ states and PR boxes in the classical limit

Daniel Rohrlich·Guy Hetzroni
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Abstract

A recent paper [1] argues that bipartite "PR-box" correlations, though designed to respect relativistic causality, in fact violate relativistic causality in the classical limit. As a test of Ref. [1], we consider GHZ correlations as a tripartite version of PR-box correlations, and ask whether the arguments of Ref. [1] extend to GHZ correlations. If they do - i.e. if they show that GHZ correlations violate relativistic causality in the classical limit - then Ref. [1] must be incorrect, since GHZ correlations are quantum correlations and respect relativistic causality. But the arguments fail. We also show that both PR-box correlations and GHZ correlations can be retrocausal, but the retrocausality of PR-box correlations leads to self-contradictory causal loops, while the retrocausality of GHZ correlations does not.

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Daniel Rohrlich, Guy Hetzroni. 2016-06-14. GHZ states and PR boxes in the classical limit. https://doi.org/10.3390/e20060478

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