The European Physical Journal B - Condensed Matter and Complex Systems

, Volume 50, Issue 3, pp 431–437

Random field Ising model and community structure in complex networks

Statistical and Nonlinear Physics

DOI: 10.1140/epjb/e2006-00155-4

Cite this article as:
Son, SW., Jeong, H. & Noh, J. Eur. Phys. J. B (2006) 50: 431. doi:10.1140/epjb/e2006-00155-4


We propose a method to determine the community structure of a complex network. In this method the ground state problem of a ferromagnetic random field Ising model is considered on the network with the magnetic field Bs = +∞, Bt = -∞, and Bi≠s,t=0 for a node pair s and t. The ground state problem is equivalent to the so-called maximum flow problem, which can be solved exactly numerically with the help of a combinatorial optimization algorithm. The community structure is then identified from the ground state Ising spin domains for all pairs of s and t. Our method provides a criterion for the existence of the community structure, and is applicable equally well to unweighted and weighted networks. We demonstrate the performance of the method by applying it to the Barabási-Albert network, Zachary karate club network, the scientific collaboration network, and the stock price correlation network. (Ising, Potts, etc.)


89.75.Hc Networks and genealogical trees89.65.-s Social and economic systems05.10.-a Computational methods in statistical physics and nonlinear dynamics05.50.+q Lattice theory and statistics

Copyright information

© EDP Sciences/Società Italiana di Fisica/Springer-Verlag 2006

Authors and Affiliations

  1. 1.Department of PhysicsKorea Advanced Institute of Science and TechnologyDaejeonKorea
  2. 2.Department of PhysicsChungnam National UniversityDaejeonKorea