Strong coupling in massive gravity by direct calculation

TL;DR

This paper confirms the strong coupling scale in four-dimensional massive gravity with Fierz-Pauli mass term through explicit calculations of scattering amplitudes and loop corrections, highlighting the theory's limitations at high energies.

Contribution

The paper provides a direct calculation confirming the strong coupling scale in massive gravity, supporting previous scalar sector analyses.

Findings

Strong coupling scale confirmed at rac{1}{5}

Explicit four-graviton scattering calculations performed

Loop corrections to source interactions analyzed

Abstract

We consider four-dimensional massive gravity with the Fierz-Pauli mass term. The analysis of the scalar sector has revealed recently that this theory becomes strongly coupled above the energy scale \Lambda = (M_{Pl}^2 m^4)^{1/5} where m is the mass of the graviton. We confirm this scale by explicit calculations of the four-graviton scattering amplitude and of the loop correction to the interaction between conserved sources.