Unitary and Renormalizable Theory of Higher Derivative Gravity

TL;DR

This paper demonstrates that a specific fourth order derivative gravity theory in 3+1 dimensions is both perturbatively renormalizable and unitary, with implications for the behavior of Newton's constant at short distances.

Contribution

It shows that higher derivative gravity can be both renormalizable and unitary, and analyzes the running of Newton's constant within this framework.

Findings

Gravity is perturbatively renormalizable in 3+1 dimensions.

The theory describes a unitary graviton (and scalar) sector.

Newton's constant vanishes at short distances in this model.

Abstract

In 3+1 space-time dimensions, fourth order derivative gravity is perturbatively renormalizable. Here it is shown that it describes a unitary theory of gravitons (with/without an additional scalar) in a limited coupling parameter space which includes standard cosmology. The running of gravitational constant which includes contribution of graviton is computed. It is shown that generically Newton's constant vanishes at short distance in this perturbatively renormalizable and unitary theory.