Norm of the no-boundary state

2025/06/25 by Cotler, Jordan, Jensen, Kristan · 2 citations
#FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #High Energy Physics - Theory (hep-th)

paper · doi:10.48550/arxiv.2506.20547

Abstract

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^S₀ \fracZ S₀^-d(d+1)/4vol(SO(d,1)) with S₀ 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.

Citations

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Cited by

• Quantum Liouville Cosmology
• The Hilbert space of gauge theories: group averaging and the quantization of Jackiw-Teitelboim gravity

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• Absolute entropy and the observer's no-boundary state
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• Cosmological Observatories