The spread of interacting agents in scale-free networks

Nowadays the Internet has become an essential part of our daily life. On the other hand, despite of the existence of lots of anti-virus software, computer viruses still persist on the Internet, threatening the security of computer systems and causing significant financial loss. Thereby, understanding, predicting and controlling the propagation of viruses becomes increasingly important. In this paper, we investigate the dynamics of two interacting agents (virus, anti-virus software, etc), whose spreading is affected by the existence of the other. Mean-field level nonlinear differential equations are derived to describe their spreading dynamics. Analytical results show that the vanishing epidemic threshold in scale-free networks can be restored in certain circumstances. The number of infections caused by each of the two different agents is strongly affected by the interaction factors. Extensive simulation results on scale-free networks are presented, matching well with the analytical results and demonstrating the detailed behaviors of the two different agents.