2007/04/30 by Ingve Simonsen, Lubos Buzna, Karsten Peters +2 · 1 citation
Physics and Astronomy · #physics.soc-ph #physics.class-ph
paper · pdf · doi:10.1103/physrevlett.100.218701
published as Phys. Rev. Lett. 100, 218701 (2008) · 4 pages Latex, 4 figures
arxiv created 2008/04/03 · arxiv updated 2010/05/04
We study cascading failures in networks using a dynamical flow model based on simple conservation and distribution laws to investigate the impact of transient dynamics caused by the rebalancing of loads after an initial network failure (triggering event). It is found that considering the flow dynamics may imply reduced network robustness compared to previous static overload failure models. This is due to the transient oscillations or overshooting in the loads, when the flow dynamics adjusts to the new (remaining) network structure. We obtain \em upper and \em lower limits to network robustness, and it is shown that \it two time scales τ and τ0, defined by the network dynamics, are important to consider prior to accurately addressing network robustness or vulnerability. The robustness of networks showing cascading failures is generally determined by a complex interplay between the network topology and flow dynamics, where the ratio χ=τ/τ0 determines the relative role of the two of them.