"[[w:Particle detector|[P]article detectors]] in De Sitter space respond as if they are immersed in a bath of thermal radiation. However, the stress energy momentum tensor in De Sitter space is not that of thermal radiation. It's just a renormalization of the cosmological constant. So there's something a bit funny about the thermal nature of De Sitter space, and I've been interested in whether you can mine that thermal stuff..."