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Full-Text Articles in Physics
Immunization Of Complex Networks, R Pastor-Satorras, A Vespignani
Immunization Of Complex Networks, R Pastor-Satorras, A Vespignani
Alessandro Vespignani
Complex networks such as the sexual partnership web or the Internet often show a high degree of redundancy and heterogeneity in their connectivity properties. This peculiar connectivity provides an ideal environment for the spreading of infective agents. Here we show that the random uniform immunization of individuals does not lead to the eradication of infections in all complex networks. Namely, networks with scale-free properties do not acquire global immunity from major epidemic outbreaks even in the presence of unrealistically high densities of randomly immunized individuals. The absence of any critical immunization threshold is due to the unbounded connectivity fluctuations of …
Epidemic Dynamics And Endemic States In Complex Networks, R Pastor-Satorras, A Vespignani
Epidemic Dynamics And Endemic States In Complex Networks, R Pastor-Satorras, A Vespignani
Alessandro Vespignani
We study by analytical methods and large scale simulations a dynamical model for the spreading of epidemics in complex networks. in networks with exponentially bounded connectivity we recover the usual epidemic behavior with a threshold defining a critical point below that the infection prevalence is null. On the contrary, on a wide range of scale-free networks we observe the absence of an epidemic threshold and its associated critical behavior. This implies that scale-free networks are prone to the spreading and the persistence of infections whatever spreading rate the epidemic agents might possess. These results can help understanding. computer virus epidemics …
Velocity And Hierarchical Spread Of Epidemic Outbreaks In Scale-Free Networks, M Barthelemy, A Barrat, R Pastor-Satorras, A Vespignani
Velocity And Hierarchical Spread Of Epidemic Outbreaks In Scale-Free Networks, M Barthelemy, A Barrat, R Pastor-Satorras, A Vespignani
Alessandro Vespignani
We study the effect of the connectivity pattern of complex networks on the propagation dynamics of epidemics. The growth time scale of outbreaks is inversely proportional to the network degree fluctuations, signaling that epidemics spread almost instantaneously in networks with scale-free degree distributions. This feature is associated with an epidemic propagation that follows a precise hierarchical dynamics. Once the highly connected hubs are reached, the infection pervades the network in a progressive cascade across smaller degree classes. The present results are relevant for the development of adaptive containment strategies.