High Energy Physics Signatures from Inflation and Conformal Symmetry of de Sitter

TL;DR

This paper explores how the conformal symmetry of de Sitter space during inflation constrains scalar field correlators and shows that heavy fields induce specific power-law suppressed corrections, revealing new signatures in inflationary observables.

Contribution

It demonstrates, using the dS/CFT correspondence, that heavy fields cause distinctive power-law corrections to inflationary correlators, extending understanding of inflationary signatures.

Findings

Heavy fields produce O(H^2/m^2) corrections in correlators.

Conformal invariance constrains scalar correlators on super-Hubble scales.

Explicit correction computed for four-point correlator with massive scalar exchange.

Abstract

During inflation, the geometry of spacetime is described by a (quasi-)de Sitter phase. Inflationary observables are determined by the underlying (softly broken) de Sitter isometry group SO(1, 4) which acts like a conformal group on R^3: when the fluctuations are on super-Hubble scales, the correlators of the scalar fields are constrained by conformal invariance. Heavy fields with mass m larger than the Hubble rate H correspond to operators with imaginary dimensions in the dual Euclidean three-dimensional conformal field theory. By making use of the dS/CFT correspondence we show that, besides the Boltzmann suppression expected from the thermal properties of de Sitter space, the generic effect of heavy fields in the inflationary correlators of the light fields is to introduce power-law suppressed corrections of the form O(H^2/m^2). This can be seen, for instance, at the level of the four-point correlator for which we provide the correction due to a massive scalar field exchange.