The solution for the multitype version of the polymerisation process treated in earlier papers is examined, and found to present several new features, because of the necessarily complex integration path, and because of the greater number and variety of potential singularities. Cases of ‘Poisson interaction’ are particularly amenable to treatment, however, and we examine two particular cases of interest in Sections 5 and 6. One is a version of the Ising model, which shows phase transition and its character very simply. The other is a version of the farmer–trader model considered previously, which now manifests a number of features, including a discontinuous transition between agrarian and mercantile economies. A stratified Poisson-interaction model is examined in Section 7. The roles of the various singularities are clarified, and a behaviour analogous to that of the single-type case confirmed.
Does the diffusion dark matter-dark energy interaction model solve cosmological puzzles?