title: Yang-Baxter equation for the asymmetric eight-vertex model.
abstract: In this paper we study, in the manner of Baxter [R. J. Baxter Exactly Solved Models in Statistical Mechanics (Academic, New York, 1982)], the possible integrable manifolds of the asymmetric eight-vertex model. As expected, they occur when the Boltzmann weights are either symmetric or satisfy the free-fermion condition; but our analysis clarifies the reason why both manifolds need to share a universal invariant. We also show that the free-fermion condition implies three distinct classes of integrable models.
authors.affiliation: Departamento de Física, Universidade Federal de São Carlos, Caixa Postal 676, Brazil.
authors.forename: W
authors.initials: W
authors.lastname: Galleas
authors.forename: M J
authors.initials: MJ
authors.lastname: Martins