Off-critical correlations in the Ashkin-Teller model

TL;DR

This paper employs the exact scattering description of the two-dimensional Ashkin-Teller model to compute two-particle form factors, providing approximate correlation functions validated against sum rules.

Contribution

It introduces a method to calculate correlation functions in the Ashkin-Teller model using exact scattering data, enhancing analytical understanding.

Findings

Form factors computed match sum rules closely.

Approximate correlation functions are derived for the model.

Method improves analytical predictions for off-critical correlations.

Abstract

We use the exact scattering description of the scaling Ashkin-Teller model in two dimensions to compute the two-particle form factors of the relevant operators. These provide an approximation for the correlation functions whose accuracy is tested against exact sum rules.