Four spins correlation function of the $q$ states Potts model, for general values of $q$. Its percolation model limit $q \rightarrow 1$

Abstract

Under the assumption that the product of two spin operators decomposes uniquely into the degenerate conformal fields $\{\Phi_{n',n}\}$, the general expression for the correlation function of four spins is defined for the $q$ states Potts model with $q$ taking general values in the interval $1 \leq q \leq 4$. The limit of $q \rightarrow 1$ is considered in detail and the four spins function is obtained for the percolation model.