Violation of consistency relations and the protoinflationary transition

TL;DR

This paper examines how the protoinflationary transition can violate standard consistency relations, affecting inflationary parameters and potentially reconciling observational tensions, while emphasizing the need for better understanding of early universe physics.

Contribution

It demonstrates that the protoinflationary transition can break consistency relations, leading to revised estimates of inflationary parameters and highlighting the importance of spectral analysis of B modes.

Findings

Protoinflationary transition can break consistency relations.

Inflationary curvature scale may be lower than standard estimates.

Understanding spectral properties of B modes is crucial for future insights.

Abstract

If we posit the validity of the consistency relations, the tensor spectral index and the relative amplitude of the scalar and tensor power spectra are both fixed by a single slow roll parameter. The physics of the protoinflationary transition can break explicitly the consistency relations causing a reduction of the inflationary curvature scale in comparison with the conventional lore. After a critical scrutiny, we argue that the inflationary curvature scale, the total number of inflationary efolds and, ultimately, the excursion of the inflaton across its Planckian boundary are all characterized by a computable theoretical error. While these considerations ease some of the tensions between the Bicep2 data and the other satellite observations, they also demand an improved understanding of the protoinflationary transition whose physical features may be assessed, in the future, through a complete analysis of the spectral properties of the B mode autocorrelations.