Lebowitz Inequalities for Ashkin-Teller Systems

TL;DR

This paper proves Lebowitz inequalities for the Ashkin-Teller model with negative four-spin coupling, demonstrating properties related to susceptibility divergence in ferromagnetic ground states.

Contribution

It extends Lebowitz inequalities to the Ashkin-Teller model with negative coupling, aiding the analysis of phase transitions and susceptibility behavior.

Findings

Established Lebowitz inequality for the model

Extended inequalities to prove susceptibility divergence

Analyzed ferromagnetic ground state properties

Abstract

We consider the Ashkin-Teller model with negative four-spin coupling but still in the region where the ground state is ferromagnetic. We establish the standard Lebowitz inequality as well as the extension that is necessary to prove a divergent susceptibility.