Mean-field limits à la Tanaka and large deviations for particle systems with network interactions
Louis-Pierre Chaintron, Antoine Diez
TL;DR
This work generalizes Tanaka's fixed-point construction to non-exchangeable mean-field particle systems with network interactions by introducing a digraph-measure parameter that governs inter-particle connectivity. It proves well-posedness, mean-field convergence, and a large deviations principle in an abstract fixed-point framework, and shows how network structure yields tractable PDE characterizations of the limit in constant, pathwise, and adaptive graph settings. The results include a new LDP for the interaction measure and a PDE-based description when possible, with explicit treatment of constant and evolving networks via the digraph-limit formalism. The approach accommodates both deterministic and stochastic networks and clarifies the role of graph regularity and Lipschitz conditions in deriving mean-field limits and limit PDEs. Overall, it provides a unified pathway from graph-based particle interactions to continuum descriptions and probabilistic large deviations for networked mean-field systems.
Abstract
This article proposes a unified framework to study non-exchangeable mean-field particle systems with some general interaction mechanisms. The starting point is a fixed-point formulation of particle systems originally due to Tanaka that allows us to prove mean-field limit and large deviation results in an abstract setting. While it has been recently shown that such formulation encompasses a large class of exchangeable particle systems, we propose here a setting for the non-exchangeable case, including the case of adaptive interaction networks. We introduce sufficient conditions on the network structure that imply the mean-field limit and a new large deviations principle for the interaction measure. Finally, we formally highlight important models for which it is possible to derive a closed PDE characterization of the limit.
