Robustness and assortativity for diffusion-like processes in scale-free networks

Abstract

By analysing the diffusive dynamics of epidemics and of distress in complex\nnetworks, we study the effect of the assortativity on the robustness of the\nnetworks. We first determine by spectral analysis the thresholds above which\nepidemics/failures can spread; we then calculate the slowest diffusional times.\nOur results shows that disassortative networks exhibit a higher epidemiological\nthreshold and are therefore easier to immunize, while in assortative networks\nthere is a longer time for intervention before epidemic/failure spreads.\nMoreover, we study by computer simulations the sandpile cascade model, a\ndiffusive model of distress propagation (financial contagion). We show that,\nwhile assortative networks are more prone to the propagation of\nepidemic/failures, degree-targeted immunization policies increases their\nresilience to systemic risk.\n