Renormalization of the Potts model

The author studies the Potts model with a general number of states. First, he discusses the situation in which the Landau theory leads to a first order transition, but which does show fixed points of the renormalization group. Here, there are many questions which need further clarification. Then he describes, rather pedagogically, the logic behind the application of dimensional regularization to critical phenomena. He argues that this is a particularly natural approach. This technique is then applied to the Potts model, for which the critical exponents are computed to O((6-d)2), when there is a fixed point. The one state results, which correspond to the percolation problem, are compared with other calculations and with numerical simulation.