Special massive spin-2 on the de Sitter space

The theory of a massive spin-2 state on the de Sitter space - with the mass squared equal to one sixth of the curvature - is special for two reasons: (i) it exhibits an enhanced local symmetry; (ii)it emerges as a part of the model that gives rise to the self-accelerated Universe. The known problems of this theory are: either it cannot be coupled to a non-conformal conserved stress-tensor because of the enhanced symmetry, or it propagates a ghost-like state when the symmetry is constrained by the Lagrange multiplier method. Here we propose a solution to these problems in the linearized approximation.