Epidemic dynamics in finite size scale-free networks

Romualdo Pastor-Satorras, Alessandro Vespignani
2002 Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics  
Many real networks present a bounded scale-free behavior with a connectivity cut-off due to physical constraints or a finite network size. We study epidemic dynamics in bounded scale-free networks with soft and hard connectivity cut-offs. The finite size effects introduced by the cut-off induce an epidemic threshold that approaches zero at increasing sizes. The induced epidemic threshold is very small even at a relatively small cut-off, showing that the neglection of connectivity fluctuations
more » ... vity fluctuations in bounded scale-free networks leads to a strong over-estimation of the epidemic threshold. We provide the expression for the infection prevalence and discuss its finite size corrections. The present work shows that the highly heterogeneous nature of scale-free networks does not allow the use of homogeneous approximations even for systems of a relatively small number of nodes.
doi:10.1103/physreve.65.035108 pmid:11909143 fatcat:da2r45ut2fht3fzdvhx6kxaw7y