Celestial Holography meets dS/CFT
Hideo Furugori, Naoki Ogawa, Sotaro Sugishita, Takahiro Waki
TL;DR
This work builds a concrete bridge between celestial holography and the dS/CFT correspondence by mapping QFTs from flat Euclidean space R^{D+2} to theories on S^{D+1} via a Weyl rescaling and a Fourier transform, followed by an analytic continuation to de Sitter space. It shows that late/early-time dS extrapolated operators O_Δ^± can be expressed as linear combinations of celestial operators O_Δ and their shadow counterparts, revealing a nontrivial mixing rather than a simple BDHM-type dictionary. Consistency checks at two and four points demonstrate that celestial amplitudes and cosmological correlators agree under this dictionary, supporting a unified framework for transferring techniques between celestial holography and dS/CFT. The results open avenues to import dS/CFT methods, such as the cosmological bootstrap and central charge analyses, into celestial holography and suggest refined dictionaries beyond naive extrapolations. Overall, the paper provides a systematic route to connect flat-space holography with cosmological holography, enabling cross-fertilization of computational tools and physical insights.
Abstract
We provide a concrete link between celestial amplitudes and cosmological correlators. We first construct a map from quantum field theories (QFTs) in $(D+2)$-dimensional Euclidean space to theories on the $(D+1)$-dimensional sphere, through a Weyl rescaling and a Fourier transformation. An analytic continuation extends this map to a relation between QFTs in Minkowski spacetime $\text{M}_{D+2}$ and in de Sitter spacetime $\text{dS}_{D+1}$ with the Bunch-Davies vacuum. Combining this relation with celestial holography, we show that the extrapolated operators in de Sitter space can be represented by operators on the celestial sphere $S^{D}$. Our framework offers a systematic route to transfer computational techniques and physical insights between celestial holography and the dS/CFT correspondence.
