Scalar-tensor mixing from icosahedral inflation

TL;DR

This paper investigates the scalar-tensor correlations in icosahedral inflation, highlighting their potential observational significance for CMB measurements despite being perturbatively small compared to scalar fluctuations.

Contribution

It introduces the analysis of mixed scalar-tensor two-point functions in icosahedral inflation, emphasizing their possible dominance over tensor spectra and implications for CMB observations.

Findings

Mixed scalar-tensor two-point function can be larger than the tensor spectrum.

Perturbatively small but potentially observable in CMB temperature-polarization spectrum.

Provides theoretical framework within effective field theory for icosahedral inflation.

Abstract

We study the mixed scalar-tensor two-point function in icosahedral inflation. Within the regime of validity of the effective field theory, this has to be perturbatively small; in particular, much smaller than the scalar spectrum. However, it can be much bigger that the tensor spectrum itself. We discuss observational implications for the CMB temperature-polarization spectrum.