Essential nature of Newton's constant in unimodular gravity

TL;DR

This paper demonstrates that in unimodular gravity, Newton's constant is an essential coupling unaffected by field redefinitions, leading to gauge and parametrization independent renormalization group flow results.

Contribution

It establishes that Newton's constant is an essential coupling in unimodular gravity and shows the gauge and parametrization independence of its renormalization group flow.

Findings

Newton's constant is an essential coupling in unimodular gravity.

Renormalization group flow of Newton's constant is gauge independent.

Flow is also parametrization independent.

Abstract

We point out that in unimodular gravity Newton's constant is an essential coupling, i.e. it is independent of field redefinitions. We illustrate the consequences of this fact by a calculation in a standard simple approximation, showing that in this case the renormalization group flow of Newton's constant is gauge and parametrization independent.