A radial variable for de Sitter two-point functions
Manuel Loparco, Jiaxin Qiao, Zimo Sun
SciPost Phys. 18, 164 (2025) · published 21 May 2025
- doi: 10.21468/SciPostPhys.18.5.164
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Abstract
We introduce a "radial" two-point invariant for quantum field theory in de Sitter (dS) analogous to the radial coordinate used in conformal field theory. We show that the two-point function of a free massive scalar in the Bunch-Davies vacuum has an exponentially convergent series expansion in this variable with positive coefficients only. Assuming a convergent Källén-Lehmann decomposition, this result is then generalized to the two-point function of any scalar operator non-perturbatively. A corollary of this result is that, starting from two-point functions on the sphere, an analytic continuation to an extended complex domain is admissible. dS two-point configurations live inside or on the boundary of this domain, and all the paths traced by analytic continuation between dS and the sphere or between dS and Euclidean Anti-de Sitter are also contained within this domain.
Authors / Affiliations: mappings to Contributors and Organizations
See all Organizations.- 1 Manuel Loparco,
- 1 Jiaxin Qiao,
- 2 Zimo Sun