Aspects of massive gravity

TL;DR

This paper explores Lorentz invariant massive gravity, deriving the decoupling limit on de Sitter space to identify a candidate for partially massless gravity and examining the Vainshtein mechanism's limitations in the minimal model.

Contribution

It introduces a method to derive the decoupling limit on de Sitter space and investigates the properties of partially massless gravity and the Vainshtein mechanism in massive gravity models.

Findings

Identified a candidate for partially massless gravity with four propagating degrees of freedom.

Showed that the decoupling limit on de Sitter space can be derived via embedding into higher-dimensional Minkowski space.

Demonstrated limitations of static and spherical symmetry assumptions in the Vainshtein mechanism analysis.

Abstract

We report here on two works on Lorentz invariant massive gravity. In the first part, we derive the decoupling limit of massive gravity on de Sitter, relying on embedding de Sitter into an higher dimensional Minkowski spacetime. This enables us to identify the unique candidate for a partially massless gravity theory, in which only four degrees of freedom propagate, although further work showed that this property does not hold beyond the decoupling limit. In the second part, we study the fate of the Vainshtein mechanism in the minimal model of massive gravity, in which we show the limits of the often used assumptions of staticity and spherical symmetry.