On the phase of the de Sitter density of states

Yiming Chen; Douglas Stanford; Haifeng Tang; Zhenbin Yang

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arXiv · 2511.01400

On the phase of the de Sitter density of states

Yiming Chen·Douglas Stanford·Haifeng Tang·Zhenbin Yang

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Abstract

The one-loop gravitational path integral around Euclidean de Sitter space $S^D$ has a complex phase that casts doubt on a state counting interpretation. Recently, it was proposed to cancel this phase by including an observer. We explore this proposal in the case where the observer is a charged black hole in equilibrium with the de Sitter horizon. We compute the phase of the one-loop determinant within a two-dimensional dilaton gravity reduction, using both numerical and analytical methods. Our results interpolate between previous studies of a probe geodesic observer and the Nariai solution. We also revisit the prescription for going from the Euclidean path integral to the state-counting partition function, finding a positive sign in the final density of states.

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Yiming Chen, Douglas Stanford, Haifeng Tang, Zhenbin Yang. 2025-11-03. On the phase of the de Sitter density of states. https://arxiv.org/abs/2511.01400

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