Enhance the Efficiency of Heuristic Algorithm for Maximizing Modularity   Q
  Modularity Q is an important function for identifying community structure in complex networks. In this paper, we prove that the modularity maximization problem is equivalent to a nonconvex quadratic programming problem. This result provide us a simple way to improve the efficiency of heuristic algorithms for maximizing modularity Q. Many numerical results demonstrate that it is very effective. 
Yanqing Hu, Jinshan Wu, Zengru Di