Form factors, correlation functions and vertex operators in the eight-vertex model at reflectionless points

TL;DR

This paper derives simple integral formulae for form factors and explicit expressions for vertex operators in the eight-vertex model at reflectionless points, using Smirnov's axiomatic approach and vertex-face transformation.

Contribution

It provides explicit integral formulae and vertex operator expressions for the eight-vertex model at reflectionless points, advancing the understanding of its structure.

Findings

Integral formulae for form factors derived

Explicit type II vertex operators obtained

Formulas simplify at reflectionless points

Abstract

The eight-vertex model at the reflectionless points is considered on the basis of Smirnov's axiomatic approach. Integral formulae for form factors of the eight-vertex model can be obtained in terms of those of the eight-vertex SOS model, by using vertex-face transformation. The resulting formulae have very simple forms at the reflectionless points, and suggests us the explicit expressions of the type II vertex operators of the eight-vertex model.