Rolling Through a Vacuum

TL;DR

This paper investigates conditions under which slow-roll inflation can pass through metastable false vacua without disruption and explores potential observable signatures in the primordial power spectrum, suggesting Planck could detect such features.

Contribution

It provides theoretical conditions for traversing metastable false vacua during inflation and links these to observable signatures in the primordial power spectrum.

Findings

Planck can potentially detect features caused by metastable vacua

Non-detection by Planck constrains the existence of such vacua

Conditions for slow-roll inflation through false vacua are clarified

Abstract

We clarify under what conditions slow-roll inflation can continue almost undisturbed, while briefly evolving through a (semi-classically) metastable false vacuum. Furthermore, we look at potential signatures in the primordial power spectrum that could point towards the existence of traversed metastable false vacua. Interestingly, the theoretical constraints for the existence of traversable metastable vacua imply that Planck should be able to detect the resulting features in the primordial power spectrum. In other words, if Planck does not see features this immediately implies the non-existence of metastable false vacua rolled through during the inflationary epoch.