Boguñá, MariánCastellano, ClaudioPastor-Satorras, R. (Romualdo), 1967-2014-04-072014-04-0720130031-9007https://hdl.handle.net/2445/53287We develop an analytical approach to the susceptible-infected-susceptible epidemic model that allows us to unravel the true origin of the absence of an epidemic threshold in heterogeneous networks. We find that a delicate balance between the number of high degree nodes in the network and the topological distance between them dictates the existence or absence of such a threshold. In particular, small-world random networks with a degree distribution decaying slower than an exponential have a vanishing epidemic threshold in the thermodynamic limit.5 p.application/pdfeng(c) American Physical Society, 2013EpidemiologiaInternetXarxes socialsXarxes neuronals (Neurobiologia)Percolació (Física estadística)TermodinàmicaSistemes no linealsEpidemiologyInternetSocial networksNeural networks (Neurobiology)Percolation (Statistical physics)ThermodynamicsNonlinear systemsinfo:eu-repo/semantics/article6284502014-04-07info:eu-repo/semantics/openAccess