Comment on "A new, exact, gauge-invariant RG-flow equation"

TL;DR

This paper demonstrates that a recently proposed gauge-invariant RG-flow equation can be derived as a special limit of the traditional ERGE, linking new and established approaches in renormalization group analysis.

Contribution

It shows that the new gauge-invariant RG-flow equation is equivalent to the sharp cut-off limit of the well-known ERGE, clarifying their relationship.

Findings

The new RG-flow equation can be obtained from the ERGE in the sharp cut-off limit.

In this limit, the scale-dependent effective actions coincide.

The result bridges the gap between the new and traditional RG approaches.

Abstract

We show that the exact RG-flow equation introduced recently in hep-th/0207134 can be obtained in the sharp cut-off limit of the well-known ERGE. This can be expected from the fact that in this limit the new scale-dependent effective action coincides with the one which is usually considered.