Non-standard kinetic term as a natural source of non-Gaussianity

TL;DR

This paper explores how non-standard kinetic terms during reheating after inflation can lead to significant non-Gaussianities in the cosmic microwave background due to inhomogeneities inherited from long-wavelength moduli.

Contribution

It introduces a mechanism where non-standard kinetic terms cause non-Gaussianity through inherited inhomogeneities, a novel approach in inflationary cosmology.

Findings

Non-standard kinetic terms can generate observable non-Gaussianity.

Inhomogeneities from long-wavelength moduli influence post-inflationary fluctuations.

The mechanism provides a new source of non-Gaussianity in the early universe.

Abstract

We consider reheating after inflation with a non-standard kinetic term. We show that the difference in the kinetic term in different Hubble patches inherited from the long-wavelength moduli inhomogeneities may generate a significant level of non-Gaussianity after inflation.