An integrable deformation of the sine(sinh)-Gordon model -- Non-Lie algebra

Abstract

In this paper we present an integrable model in two dimensions. It is a deformation of the sine(sinh)-Gordon model. We give its Lax connection. We also obtain its (classical) $r$-matrix. It satisfies the classical Yang-Baxter equation. Thus, the model is a classical integrable field theory in two dimensions. The underlying algebra is a $\mathcal{Z}$-graded non-Lie alternative Akivis algebra. An alternative Akivis algebra is the tangent space at the identity of an analytic alternative loop as a Lie algebra is the tangent space at the identity of a Lie group. We expect the model to be integrable at the quantum level. We also give a family of classically integrable models which are related to the Poisson-Boltzmann equation in two dimensions.

arXiv commentv1. 20 p., 1 fig.; v2. 26 p, 1 fig, equations and results unchanged, extended discussion, algebra renamed correctly