Finite symmetries in agent-based epidemic models
  We present an algorithm which explores permutation symmetries to describe the time evolution of agent-based epidemic models. The main idea to improve computation times relies on restricting the stochastic process to one sector of the vector space, labeled by a single permutation eigenvalue. In this scheme, the transition matrix reduces to block diagonal form, enhancing computational performance. 
Gilberto M. Nakamura, Ana Carolina P. Monteiro, George C. Cardoso and   Alexandre S. Martinez
q-bio.PE