Pressure of massless hot scalar theory in the boundary effective theory framework

TL;DR

This paper employs the boundary effective theory approach to compute the pressure of massless hot scalar fields with quartic interactions, providing a non-perturbative and infrared-sensitive calculation that aligns well with existing results.

Contribution

It introduces a resummed pressure calculation within the boundary effective theory framework for massless scalar fields at finite temperature, emphasizing a direct and compact method.

Findings

Resummed pressure agrees with recent literature

Method effectively separates infrared physics

Approach is non-perturbative and straightforward

Abstract

We use the boundary effective theory (BET) approach to thermal field theory in order to calculate the pressure of a system of massless scalar fields with quartic interaction. The method naturally separates the infrared physics, and is essentially non-perturbative. To lowest order, the main ingredient is the solution of the free Euler-Lagrange equation with non-trivial (time) boundary conditions. We derive a resummed pressure, which is in good agreement with recent calculations found in the literature, following a very direct and compact procedure.