Epidemic spreading in scale-free networks with community structure

Many real networks consist of communities: groups of nodes within which connections are dense, but among which connections are sparser. In this paper, based on the susceptible-infected ( SI) model, epidemic prevalence is compared between two kinds of scale-free network, with and without community structure, which have the same degree distribution. It is found that networks with strong community structure are helpful for reducing the danger brought by epidemic prevalence in the network, which is shown by the comparison results of the prevalence scale, the variability of the prevalence scale and the average degree of new infected nodes at each time step. We also note that when facing networks with strong community structure, special attention should be paid to nodes that are close to the initial infected seeds.