Ruling out bipartite nonsignaling nonlocal models for tripartite correlations

Many three-party correlations, including some that are commonly described as genuinely tripartite nonlocal, can be simulated by a network of underlying subsystems that display only bipartite nonsignaling nonlocal behavior. Quantum mechanics predicts three-party correlations that admit no such simulation, suggesting there are versions of nonlocality in nature transcending the phenomenon of bipartite nonsignaling nonlocality. This paper introduces a rigorous framework for analyzing tripartite correlations that can be simulated by bipartite-only networks. We confirm that expected properties of so-obtained correlations, such as no-signaling, indeed hold, and show how to use the framework to derive Bell-inequality-type constraints on these correlations that can be robustly violated by tripartite quantum systems. In particular, we use this framework to rederive a version of one such constraint previously described in a paper of Chao and Reichardt, Test to separate quantum theory from non-signaling theories [arXiv:1706.02008 (2017)].

Automated summary

This paper introduces a rigorous framework for analyzing tripartite correlations that can be simulated by bipartite-only networks. The expected properties of these correlations, such as no-signaling, are confirmed to hold, and the framework is used to derive Bell-inequality-type constraints that can be robustly violated by tripartite quantum systems. Additionally, the framework is used to rederive a version of a constraint previously described in a paper by Chao and Reichardt.