论文部分内容阅读
The percolation-like phase transition of mobile individuals is studied on weighted scale-free (WSF) networks,in which the maximum occupancy at each node is one individual (i.e.hard core interaction) and individuals can move to neighbor void node.Especially,the condition for the existence of a spanning cluster of individuals (a connected cluster of neighbor nodes occupied by individuals that span the entire systems) is investigated and it is found that there exists a critical value of weight coupling parameter βc,above which the density threshold of individuals is zero and below which the density threshold is larger than zero for WSF networks in the thermodynamic limit N → ∞.Furthermore,the finite size scaling analysis show that for certain value β,the percolation transition of mobile individuals on a WSF network belongs to the same universality class of regular random graph percolation.In the past decade,the study of networks science shows that many realistic networks,such as the Inteet,nets of social contacts and ecological nets of predator-prey,are scale-free networks,[1,2] whose degree distributions and the probability that any node has k connections to other nodes,follow the power law P(k) ~ k-γ with degree exponent 2 < γ ≤ 3.Percolation theory was used to study the topology of a network resulting from removal of a fraction of nodes (or links) from a system.Percolation in scale-free networks has many connections to real systems.Applications range from disease propagation to the robustness of communication networks.One of the most striking results is the nonexistence of a percolation threshold on uncorrelated scale-free networks.[3] Subsequent work investigated percolation on network with a more detailed topological characterization (such as degree correlations[4,5] and cluster structure,[6] etc.),and more realistic mechanisms.[7]