2002/02/18 by Romualdo Pastor-Satorras, Alessandro Vespignani
Physics and Astronomy · Biochemistry, Genetics and Molecular Biology · #cond-mat.stat-mech #q-bio
paper · pdf · doi:10.1103/physreve.65.035108
published as Phys. Rev. E. 65, 035108(R) (2002) · 4 pages, 2 eps figures
arxiv created 2002/02/18 · arxiv updated 2009/11/30
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 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.