Coupled spreading dynamics in information–physical–social multilayer system

In the study of infectious-disease spreading, individual risk perception and the dynamic allocation of medical resources are two core determinants of epidemic control, while the interplay between these two factors has been overlooked in terms of its influence on epidemic dynamics. To fill this gap, we propose a novel “information–physical–social” three-layer coupled model to describe the coevolution of information diffusion, disease spreading, and resource allocation, and further incorporates two coupling mechanisms between information diffusion and resource allocation, namely independent co-coupling and dependent co-coupling. Combining a microscopic Markov-chain approximation with Monte Carlo simulations, we find that independent co-coupling not only significantly enhances the epidemic threshold, but also promotes a crossover phenomenon from an explosive phase transition to a hybrid phase transition. In contrast, dependent co-coupling makes the system more fragile and weakens the synergistic suppression achieved by information diffusion and resource allocation. These findings provide theoretical support and practical insights for optimizing resource allocation and designing intervention strategies.