English

SIR on locally converging dynamic random graphs

Probability 2025-01-17 v1

Abstract

In this paper, we study the trajectory of a classic SIR epidemic on a family of dynamic random graphs of fixed size, whose set of edges continuously evolves over time. We set general infection and recovery times, and start the epidemic from a positive, yet small, proportion of vertices. We show that in such a case, the spread of an infectious disease around a typical individual can be approximated by the spread of the disease in a local neighbourhood of a uniformly chosen vertex. We formalize this by studying general dynamic random graphs that converge dynamically locally in probability and demonstrate that the epidemic on these graphs converges to the epidemic on their dynamic local limit graphs. We provide a detailed treatment of the theory of dynamic local convergence, which remains a relatively new topic in the study of random graphs. One main conclusion of our paper is that a specific form of dynamic local convergence is required for our results to hold.

Keywords

Cite

@article{arxiv.2501.09623,
  title  = {SIR on locally converging dynamic random graphs},
  author = {Marta Milewska and Remco van der Hofstad and Bert Zwart},
  journal= {arXiv preprint arXiv:2501.09623},
  year   = {2025}
}
R2 v1 2026-06-28T21:08:27.977Z