On Loops in Inflation III: Time Independence of zeta in Single Clock Inflation

Understand

Studying loop corrections to inflationary perturbations, with particular emphasis on infrared factors, is important to understand the consistency of the inflationary theory, its predictivity and to establish the existence of the slow-roll eternal inflation phenomena and its recently found volume bound.

• In this paper we prove that the zeta correlation function is time-independent at one-loop level in single clock inflation.
• While many of the one-loop diagrams lead to a time-dependence when considered individually, the time-dependence beautifully cancels out in the overall sum.
• We identify two subsets of diagrams that cancel separately due to different physical reasons.