Title: A Sphere Approach to in-in Correlators

 

Abstract:

The sphere can be understood as a Wick rotation of de Sitter (dS) spacetime. It is believed that in-in correlators in dS are equivalently computable from correlators on the sphere. In this talk, I will present a concrete framework for computing sphere correlators and systematically mapping them to late-time cosmological correlators. Using this approach, I will test the conjecture “sphere = in-in” for several non-trivial classes of diagrams. I will also discuss the advantages of the sphere method, particularly for numerical computations.