Vacuum States and the S-Matrix in dS/CFT

TL;DR

This paper defines dS/CFT correlation functions via S-matrix elements, constructs de Sitter invariant vacua for a scalar field, and links these vacua to CFT deformations through three-point function calculations.

Contribution

It introduces a new approach to dS/CFT by relating correlation functions to S-matrix elements and constructs a family of invariant vacua in de Sitter space.

Findings

Vacua constructed via analytic continuation lack particles on the past horizon.

Evidence that the vacua correspond to marginal deformations of the CFT.

Provided a formalism connecting de Sitter vacua with CFT correlation functions.

Abstract

We propose a definition of dS/CFT correlation functions by equating them to S-matrix elements for scattering particles from I^- to I^+. In planar coordinates, which cover half of de Sitter space, we consider instead the S-vector obtained by specifying a fixed state on the horizon. We construct the one-parameter family of de Sitter invariant vacuum states for a massive scalar field in these coordinates, and show that the vacuum obtained by analytic continuation from the sphere has no particles on the past horizon. We use this formalism to provide evidence that the one-parameter family of vacua corresponds to marginal deformations of the CFT by computing a three-point function.