Han-Xin Yang

Role of aspiration-induced migration in cooperation.

Both cooperation and migration are ubiquitous in human society and animal world. In this Rapid Communication, we propose an aspiration-induced migration in which individuals will migrate to new sites provided that their payoffs are below some aspiration level. It is found that moderate aspiration level can best favor cooperative behavior. In particular, moderate aspiration level enables cooperator clusters to maintain and expand whereas induces defector clusters to disintegrate, thus promoting the diffusion of cooperation among population. Our results provide insights into understanding the role played by migration in the emergence of cooperative behavior.

Aspiration-induced reconnection in spatial public-goods game

In this letter, we introduce an aspiration-induced reconnection mechanism into the spatial public-goods game. A player will reconnect to a randomly chosen player if its payoff acquired from the group centered on the neighbor does not exceed the aspiration level. We find that an intermediate aspiration level can promote cooperation best. This optimal phenomenon can be explained by a negative feedback effect, namely, intermediate aspiration level is able to result in a weak peak of reconnection, which will effectively change the downfall of cooperators and facilitate the fast spreading of cooperation. While insufficient reconnection and excessive reconnection induced by low and high aspiration levels are not conductive to such an effect. Moreover, we find that the intermediate aspiration level can lead to the heterogeneous distribution of degree, which will be beneficial to the evolution of cooperation.

Traffic dynamics in scale-free networks with limited packet-delivering capacity

We propose a limited packet-delivering capacity model for traffic dynamics in scale-free networks. In this model, the total node’s packet-delivering capacity is fixed, and the allocation of packet-delivering capacity on node i is proportional to kiϕ, where ki is the degree of node i and ϕ is a adjustable parameter. We have applied this model on the shortest path routing strategy as well as the local routing strategy, and found that there exists an optimal value of parameter ϕ leading to the maximal network capacity under both routing strategies. We provide some explanations for the emergence of optimal ϕ.

Cooperation percolation in spatial prisoner's dilemma game

The paradox of cooperation among selfish individuals still puzzles scientific communities. Although a large amount of evidence has demonstrated that cooperator clusters in spatial games are effective to protect cooperators against the invasion of defectors, we continue to lack the condition for the formation of a giant cooperator cluster that assures the prevalence of cooperation in a system. Here, we study the dynamical organization of cooperator clusters in spatial prisoners dilemma game to offer the condition for the dominance of cooperation, finding that a phase transition characterized by the emergence of a large spanning cooperator cluster occurs when the initial fraction of cooperators exceeds a certain threshold. Interestingly, the phase transition belongs to different universality classes of percolation determined by the temptation to defect

Transportation dynamics on networks of mobile agents.

b

Evolutionary games on scale-free networks with tunable degree distribution

. Specifically, on square lattices,

Impact of heterogeneous activity and community structure on the evolutionary success of cooperators in social networks.

1<b<4/3

Social dilemma alleviated by sharing the gains with immediate neighbors.

leads to a phase transition pertaining to the class of regular site percolation, whereas

Suppressing traffic-driven epidemic spreading by edge-removal strategies.

3/2<b<2

Reducing the heterogeneity of payoffs: an effective way to promote cooperation in the prisoner's dilemma game.

gives rise to a phase transition subject to invasion percolation with trapping. Our findings offer deeper understanding of the cooperative behaviors in nature and society.