Assessing the relative importance of high-order interactions versus dyadic relations
Determine a quantitative framework to assess the relative importance of high-order (polyadic) interactions among components of complex systems compared to dyadic (pairwise) relations, so as to evaluate how multi-variable dependencies contribute to observed information flow relative to two-variable dependencies.
References
However, assessing the relative importance of these high-order interactions compared to dyadic relations remains an open problem.
A central open problem is to connect governing mechanisms to the higher-order signatures that can actually be measured. For equilibrium systems, the joint distribution $p_N(\mathbf{s})$ provides a natural probabilistic description; for dynamical systems, the corresponding object is more generally a transition law or probability distribution over trajectories. Developing a framework that connects these descriptions to interaction structure, collective behaviour and the reducibility criterion of Eq.~eq:reducibility would help place the diverse approaches reviewed here on a common footing.
The Dowker complex records whether a set of entities occurred together; whether it occurred more often than its pairs imply is a separate, statistical question.