Title: Cascading Failures in Interdependent Systems: Impact of Degree Variability and Dependence,
Abstract: We study cascading failures in a system comprising interdependent
networks/systems, in which nodes rely on other nodes both in the same system
and in other systems to perform their function. The (inter-)dependence among
nodes is modeled using a dependence graph, where the degree vector of a node
determines the number of other nodes it can potentially cause to fail in each
system through aforementioned dependency. In particular, we examine the impact
of the variability and dependence properties of node degrees on the probability
of cascading failures. We show that larger variability in node degrees hampers
widespread failures in the system, starting with random failures. Similarly,
positive correlations in node degrees make it harder to set off an epidemic of
failures, thereby rendering the system more robust against random failures.