All reversible dynamics in maximally non-local theories are trivial

Understand

A remarkable feature of quantum theory is non-locality (i.e.

• the presence of correlations which violate Bell inequalities).
• However, quantum correlations are not maximally non-local, and it is natural to ask whether there are compelling reasons for rejecting theories in which stronger violations are possible.
• To shed light on this question, we consider post-quantum theories in which maximally non-local states (non-local boxes) occur.