Physical review. B, Condensed matter
Bond percolation on a finite lattice: Critical behavior of the (1+ε)-state Potts model
Joseph Rudnick, Jacob Morris, George Gaspari
Abstract
The continuous n-state Potts model is reinvestigated. The partition function is cast in a form allowing the limit, n\ensuremath{\rightarrow}1, to be taken prior to perturbation-theoretical expansions. Proceeding in this way, we free the theory of pathologies known to plague other approaches. Several alternatives are presented for a Feynman-diagrammatic expansion of the theory, two of which are identical to those utilized in previous analyses of the mdoel. One of the introduced diagrammatic approaches is used to recover known results of one-loop renormalization calculations. It is also utilized to calculate the partition function of the (1+\ensuremath{\epsilon})-state Potts model, and, hence, the generating function for bond percolation, on a finite lattice. This generating function for cluster statistics exhibits the scaling features proposed by Privman and Fisher for systems of finite size.