Fixed Points of Higher Derivative Gravity

TL;DR

This paper recalculates the beta functions in higher derivative gravity, revealing a non-Gaussian fixed point indicating asymptotic safety rather than perturbative renormalizability.

Contribution

It provides new terms for the beta functions of Newton's constant and the cosmological constant using the Exact Renormalization Group approach.

Findings

Reproduces known beta functions for dimensionless couplings.

Finds new terms for beta functions of Newton's constant and cosmological constant.

Suggests the theory is asymptotically safe at a non-Gaussian fixed point.

Abstract

We recalculate the beta functions of higher derivative gravity in four dimensions using the one--loop approximation to an Exact Renormalization Group Equation. We reproduce the beta functions of the dimensionless couplings that were known in the literature but we find new terms for the beta functions of Newton's constant and of the cosmological constant. As a result, the theory appears to be asymptotically safe at a non--Gaussian Fixed Point, rather than perturbatively renormalizable and asymptotically free.