A bstract We study the fundamentals of quantum field theory on a rigid de Sitter space. We
show that the perturbative expansion of late-time correlation functions to all orders can be …

A bstract We describe in more detail the general relation uncovered in our previous work
between boundary correlators in de Sitter (dS) and in Euclidean anti-de Sitter (EAdS) space …

We study solutions of the Klein-Gordon, Maxwell, and linearized Einstein equations in R 1,
d+ 1 that transform as d-dimensional conformal primaries under the Lorentz group SO (1, d+ …

A bstract It is a long-standing conjecture that any CFT with a large central charge and a large
gap∆ gap in the spectrum of higher-spin single-trace operators must be dual to a local …

A bstract We develop a Mellin space approach to boundary correlation functions in anti-de
Sitter (AdS) and de Sitter (dS) spaces. Using the Mellin-Barnes representation of correlators …

A bstract We discuss consequences of the breaking of conformal symmetry by a flat or
spherical extended operator. We adapt the embedding formalism to the study of correlation …

A bstract We compare and contrast the two approaches of holography in asymptotically flat
spacetimes, viz. the co-dimension two Celestial approach based on the Mellin …

A bstract The four-dimensional S-matrix is reconsidered as a correlator on the celestial
sphere at null infinity. Asymptotic particle states can be characterized by the point at which …

A bstract We propose a Mellin space approach to the evaluation of late-time momentum-
space correlation functions of quantum fields in (d+ 1)-dimensional de Sitter space. The …

A bstract We study two-point functions of symmetric traceless local operators in the bulk of
de Sitter spacetime. We derive the Källén-Lehmann spectral decomposition for any spin and …