On manifolds with an even Riemannian conformally compact Einstein metric, the resolvent of the Lichnerowicz Laplacian, acting on trace-free, divergence-free, symmetric 2-tensors is shown to have a meromorphic continuation to the complex plane, defining quantum resonances of this Laplacian. For higher-rank symmetric tensors, a similar result is proven for (convex cocompact) quotients of hyperbolic space.
Charles Hadfield. "Resonances for symmetric tensors on asymptotically hyperbolic spaces." Anal. PDE 10 (8) 1877 - 1922, 2017. https://doi.org/10.2140/apde.2017.10.1877