A REAL-SPACE RENORMALIZATION-GROUP APPROACH TO THE FERROMAGNETIC POTTS-MODEL ON THE 2-DIMENSIONAL OCTAGONAL QUASI-PERIODIC TILING

A one-step real-space renormalization group (RSRG) transformation is u sed to study the ferromagnetic (FM) g-state Potts model on the two-dim ensional (2D) octagonal quasiperiodic tiling (OQT). The critical expon ents of the correlation length nu for different values of q and the cr itical temperature of the Ising model are obtained. The results are sh own to be not sensitive to the choice of parameters. The comparison of the results with previous results for the OQT and the square lattice (SQL) seems to show that the universal classes of the q-state Potts mo dels on the OQT and the SQL are the same for the range from q = 1 to q = 3, in accordance with previous research.