On Quadratic Gravity

TL;DR

Quadratic Gravity, involving quadratic curvature terms, is a promising renormalizable approach to quantum gravity with unique field-theoretic features, maintaining the metric as the fundamental variable.

Contribution

The paper provides an overview of Quadratic Gravity, highlighting its potential as a renormalizable quantum gravity theory with distinctive propagator properties.

Findings

Quadratic Gravity includes quadratic curvature terms in the action.

It remains a viable candidate for quantum gravity despite unusual propagator behavior.

The theory maintains the metric as the fundamental dynamical variable.

Abstract

We provide a brief overview of what is known about Quadratic Gravity, which includes terms quadratic in the curvatures in the fundamental action. This is proposed as a renormalizeable UV completion for quantum gravity which continues to use the metric as the fundamental dynamical variable. However, there are unusual field-theoretic consequences because the propagators contain quartic momentum dependence. At the present stage of our understanding, Quadratic Gravity continues to be a viable candidate for a theory of quantum gravity.