Extension of a new method for locating critical temperatures

Abstract

We investigate recently proposed method for locating critical temperatures and introduce some modifications which allow to formulate exact criterion for any self-dual model. We apply the modified method for the Ashkin-Teller model and show that the exact result for a critical temperature is reproduced. We test also a two-layer Ising model for the presence of eventual self-duality.

Comments: 3 pages, Latex, espcrc2.sty, Talk given at Lattice'97