On the Finite Temperature Formalism in Integrable Quantum Field Theories

TL;DR

This paper compares two recent theoretical approaches to finite temperature effects in integrable quantum field theories by explicitly testing their predictions against Thermodynamical Bethe Ansatz results for a specific model.

Contribution

It provides an explicit validation of the correct finite temperature formalism in integrable quantum field theories through a detailed comparison with TBA predictions.

Findings

One of the formalisms accurately predicts the one-point function.

The other formalism shows discrepancies with TBA results.

The correct formalism is confirmed for the specific model studied.

Abstract

Two different theoretical formulations of the finite temperature effects have been recently proposed for integrable field theories. In order to decide which of them is the correct one, we perform for a particular model an explicit check of their predictions for the one-point function of the trace of the stress-energy tensor, a quantity which can be independently determined by the Thermodynamical Bethe Ansatz.