1212.5835 (S. Deser et al.)

Acausality of Massive Gravity    [PDF]

S. Deser, A. Waldron

We show that (at least one of) the Wess--Zumino (1970) ghost-free 5 degree of freedom massive gravity models is acausal. By analyzing its characteristics, we demonstrate that shock wave solutions exhibit superluminal behavior. Ironically, this pathology arises from the very constraint that removes the Boulware-Deser ghost mode.

View original: http://arxiv.org/abs/1212.5835