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We introduce a "radial" two-point invariant for quantum field theory in deSitter (dS) analogous to the radial coordinate used in conformal field theory.We show that the two-point function of a free massive scalar in theBunch-Davies vacuum has an exponentially convergent series expansion in thisvariable with positive coefficients only. Assuming a convergentK\"all\'en-Lehmann decomposition, this result is then generalized to thetwo-point function of any scalar operator non-perturbatively. A corollary ofthis result is that, starting from two-point functions on the sphere, ananalytic continuation to an extended complex domain is admissible. dS two-pointconfigurations live inside or on the boundary of this domain, and all the pathstraced by Wick rotations between dS and the sphere or between dS and EuclideanAnti-de Sitter are also contained within this domain.

A radial variable for de Sitter two-point functions