Appearance and disappearance of thermal renormalons

TL;DR

This paper investigates how thermal effects influence the presence of renormalons in a scalar field theory, showing that increasing temperature introduces new renormalons but at very high temperatures, all renormalons vanish, making the theory Borel summable.

Contribution

It demonstrates how temperature affects the renormalon structure in a scalar field model, revealing the disappearance of renormalons at high temperatures.

Findings

Small temperature increases add new renormalons.

Renormalons' positions and residues depend on temperature.

At extremely high temperatures, all renormalons disappear.

Abstract

We consider a scalar field model with a $g \phi_4^4$ interaction and compute the mass correction at next-to-leading order in a large-$N$ expansion to study the summability of the perturbative series. It is already known that at zero temperature this model has a singularity in the Borel plane (a "renormalon"). We find that a small increase in temperature adds two countable sets both with an infinite number of renormalons. For one of the sets the position of the poles is thermal independent and the residue is thermal dependent. In the other one both the position of poles and the residues are thermal dependent. If we consider the model at extremely high temperatures, however, one observes that all the renormalons disappear and the model becomes Borel summable.