Extend optimized-channel macroscopic-locality recovery

Establish whether recovery of macroscopic locality through optimized communication channels extends to more general bipartite Bell scenarios.

Background

The paper derives the macroscopic-locality constraint in the simplest bipartite Bell scenario by optimizing over correlated inputs and suitably chosen communication channels in the vanishing-capacity limit. The derivation relies on the special structure of two binary inputs and outputs.

It remains unresolved whether the same optimized-channel method can recover macroscopic locality in more general bipartite Bell scenarios, such as scenarios with more measurement settings or outcomes.

References

The full power of IC is still unknown, even in the simplest Bell scenario. Can a different protocol yield constraints beyond ML already at leading order in the vanishing-capacity limit? Does the recovery of ML through optimized communication channel extend to more general bipartite Bell scenarios?

— Information Causality Characterizes the Set of Quantum Correlations in the Simplest Bell Scenario  (2609.10508 - Gachechiladze et al., 9 Sep 2026) in Section Discussion