dRGT ghost-free massive gravity in spherical symmetry

In my talk, I will argue that symmetry strongly changes the behaviour of massive gravity relative to its massless sibling.

 

After reviewing the formulation of dRGT theory of ghost-free massive gravity, I will examine the minimal model and next-to-minimal model in spherical symmetry.

Although the latter has been argued to have a good Vainshtein mechanism in spherical symmetry, I will derive a restriction on non-relativistic matter that is at odds with a reasonable phenomenology. Moreover, the theory cannot reproduce the same behaviour as GR for a scalar field collapse in the small mass limit without encountering a singularity at some point in the evolution.

 

Since symmetry is the epitome of non-genericity, the resolution may well be that we should forgo symmetry and focus on more generic behaviour in massive gravity to study the screening mechanism.

This talk is based on