`Hidden' symmetry of linearized gravity in de Sitter space

Abstract

We demonstrate that the linearized Einstein gravity in de Sitter (dS) spacetime besides the evident symmetries also possesses the additional (local) symmetry $h_{\mu\nu}\rightarrow h_{\mu\nu} + {\cal E}_{\mu\nu}\chi$, where ${\cal E}_{\mu\nu}$ is a spin-two projector tensor and $\chi$ is an arbitrary constant function. We argue that an anomalous symmetry associated with this hitherto `hidden' property of the existing physics is indeed at the origin of `dS breaking' in linearized quantum gravity.