Reliability of the Optimized Perturbation Theory for scalar fields at finite temperature

TL;DR

This paper evaluates the reliability of the Optimized Perturbation Theory (OPT) in calculating the thermodynamics of a massless scalar field with quartic interaction at finite temperature, comparing it with other nonperturbative methods.

Contribution

It provides an assessment of OPT's accuracy and reliability in finite-temperature scalar field thermodynamics up to third order.

Findings

OPT shows consistent results with other nonperturbative approaches.

Third-order calculations improve the accuracy of thermodynamic predictions.

The study validates OPT as a reliable method for finite-temperature scalar field analysis.

Abstract

The thermodynamics of a massless scalar field with a quartic interaction is studied up to third order in the Optimized Perturbation Theory (OPT) method. A comparison with other nonperturbative approaches is performed such that the reliability of OPT is accessed.