Inflation and deformation of conformal field theory

Understand

It has recently been suggested that a strongly coupled phase of inflation may be described holographically in terms of a weakly coupled quantum field theory (QFT).

• Here, we explore the possibility that the wave function of an inflationary universe may be given by the partition function of a boundary QFT.
• We consider the case when the field theory is a small deformation of a conformal field theory (CFT), by the addition of a relevant operator O, and calculate the primordial spectrum predicted in the corresponding holographic inflation scenario.
• Using the Ward-Takahashi identity associated with Weyl rescalings, we derive a simple relation between correlators of the curvature perturbation and correlators of the deformation operator O at the boundary.