Accuracy criterion for mean field approximations of Markov processes on hypergraphs
Illes Horvath, Daniel Keliger
TL;DR
This work provides rigorous error bounds for the N-intertwined mean field approximation (NIMFA) of local density-dependent Markov population processes on hypergraphs, showing that NIMFA is accurate when typical vertices have many neighbors. By constructing an auxiliary process with independent neighborhoods, the authors derive uniform, local error bounds that scale with the network’s weight distribution characteristics ($w_{\max}^{*}$ and the normalized Frobenius norm $\frac{1}{N}\sum_{i,j} w_{ij}^2$) and hold across various network models. The paper further demonstrates how NIMFA can be reduced to simpler widely-used approximations, including homogeneous mean-field, metapopulation models (graphs and hypergraphs), annealed networks, activation-driven networks, and Szemerédi-regularity-based coarse-graining for dense graphs, under suitable regularity assumptions. These results clarify when and how higher-order interactions and network structure influence mean-field approximations, and they provide practical pathways to scalable analyses of large complex networks. Overall, the work offers a unified, theory-backed framework for applying NIMFA across diverse domains such as epidemiology, statistical physics, and opinion dynamics, with explicit error control and scalable reductions.
Abstract
We provide error bounds for the N-intertwined mean-field approximation (NIMFA) for local density-dependent Markov population processes with a well-distributed underlying network structure showing NIMFA being accurate when a typical vertex has many neighbors. The result justifies some of the most common approximations used in epidemiology, statistical physics and opinion dynamics literature under certain conditions. We allow interactions between more than 2 individuals, and an underlying hypergraph structure accordingly.
