Quantum Aspects of Massive Gravity

TL;DR

This paper investigates quantum effects in massive gravity, revealing that generic interactions introduce ghosts at one-loop level, and derives conditions to avoid these ghosts through resummed propagator analysis.

Contribution

It provides a detailed quantum analysis of massive gravity, identifying conditions to prevent ghost modes and exploring the impact of quantum interactions on the theory's consistency.

Findings

One-loop counterterms break the tree-level structure, reintroducing ghosts.

Resummed propagator analysis yields a minimal ghost-free condition.

Generic cubic interactions lead to ghost reappearance at quantum level.

Abstract

We consider the effect of quantum interactions on Pauli-Fierz massive gravity. With generic graviton cubic interactions, we observe that the 1-loop counterterms do not conform to the tree level structure of Pauli-Fierz action, resulting in the reappearance of the 6th mode ghost. Then to explore the quantum effects to the full extent, we calculate the resummed graviton propagator with an arbitrary interaction and analyze its complete structure, from which a minimal condition for the absence of the ghost is obtained.