Universality of Hard-Loop Action

TL;DR

This paper demonstrates that the effective actions of gauge bosons, fermions, and scalars in various gauge theories exhibit a universal form within the hard-loop approximation, leading to similar plasma behaviors across different theories.

Contribution

It reveals the universal structure of hard-loop effective actions across a wide class of gauge theories, regardless of their specific field content or interactions.

Findings

Universal form of effective actions across theories

Similar collective plasma excitations in different gauge theories

Universality holds within the hard-loop approximation limits

Abstract

The effective actions of gauge bosons, fermions and scalars, which are obtained within the hard-loop approximation, are shown to have unique forms for a whole class of gauge theories including QED, scalar QED, super QED, pure Yang-Mills, QCD, super Yang-Mills. The universality occurs irrespective of a field content of each theory and of variety of specific interactions. Consequently, the long-wavelength or semiclassical features of plasma systems governed by these theories such as collective excitations are almost identical. An origin of the universality, which holds within the limits of applicability of the hard-loop approach, is discussed.