Impact of hopping characteristics of inter-layer commuters on epidemic spreading in multilayer networks

People travel frequently between communities, and the movement of population affects the spreading dynamics of epidemic and information within/between communities. Here we establish a two-layer network where the inter-layer coupling is induced by the movement of individuals between layers, and study the impact of the travellers' hopping preference and activity on the epidemic spreading dynamics. Through large numerical simulations and theoretical analysis on synthesized networks and empirical networks, we find that travellers' hopping preference for different layers has opposite effects on the spreading dynamics within layers and the coupling between layers, resulting in interesting non-monotonic changes in the epidemic threshold and spreading coverage. On the contrary, the impact of travellers' hopping activity on the spreading of epidemic displays a monotonous trend. Based on quenched mean-field approximation, we proposed a theoretical framework that can accurately describe the spreading dynamics in two-layer networks with inter-layer hopping. Our research provides a method and theoretical framework to describe real-world scenarios where human movement and epidemic spreading coevolve.