Answers are grounded in this paper and cite their sources.
It is shown that a branch point appears in the critical surface of the Ashkin-Teller model at the point where this model reduces to a Potts model, and its relation with the eight-vertex model is discussed. An estimate for the critical exponent alpha of the Potts model is given.
No takes yet. Share an insight, caveat, or question.
H. J. F. Knops (1975) studied this question.
Synapse has enriched 5 related papers. Consider them for comparative context: