We consider Einstein gravity with positive cosmological constant coupled to matter in an asymptotically de Sitter universe with sphere boundary at timelike infinity. In this setting we show that, to one-loop order and at late time, the norm of the no-boundary state vanishes, going as $e^{ S_0} \frac{ Z S_0^{ -d(d+1)/4}}{ \text{ vol}(SO(d,1))}$ with $S_0$ the tree-level entropy of the static patch, $d$ the spacetime dimension, and $Z$ non-negative. We show that the presence of an observer stabilizes the norm to a large, positive value.
Categories: hep-th gr-qc