Pressure of the O(N) Model in 1+1 Dimensions

TL;DR

This paper analytically investigates the thermodynamic pressure of the 1+1 dimensional O(3) model, highlighting its similarities with Yang-Mills theories and validating results against lattice simulations.

Contribution

It introduces an analytical method using the CJT formalism and auxiliary fields to compute the pressure of the O(3) model, comparing it with lattice data.

Findings

Analytical pressure calculation aligns with lattice results.

The approach captures key features like asymptotic freedom and mass gap.

Method provides a new tool for non-perturbative thermodynamics in similar models.

Abstract

The O(N) model in 1+1 dimensions presents some features in common with Yang-Mills theories: asymptotic freedom, trace anomaly, non-petrurbative generation of a mass gap. An analytical approach to determine the termodynamical properties of the O(3) model is presented and compared to lattice results. Here the focus is on the pressure: it is shown how to derive the pressure in the CJT formalism at the one-loop level by making use of the auxiliary field method. Then, the pressure is compared to lattice results.