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 such 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, obtaining a new proof for one such constraint previously described in by Chao and Reichardt in arXiv:1706.02008.