Non-commutative Geometry Modified Non-Gaussianities of Cosmological Perturbation

TL;DR

This paper explores how noncommutative geometry influences the non-Gaussian features of primordial cosmological perturbations, revealing potentially observable effects in certain inflation models with low string scales.

Contribution

It introduces the impact of noncommutative effects on non-Gaussianities in cosmology, highlighting observable modifications in models with small sound speed and specific string scales.

Findings

Noncommutative effects can significantly modify non-Gaussianity estimators.

Corrections depend on sound speed and string length scale.

Modified non-Gaussianity shapes differ from standard predictions.

Abstract

We investigate the noncommutative effect on the non-Gaussianities of primordial cosmological perturbation. In the lowest order of string length and slow-roll parameter, we find that in the models with small speed of sound the noncommutative modifications could be observable if assuming a relatively low string scale. In particular, the dominant modification of non-Gaussianity estimator f_{NL} could reach O(1) in DBI inflation and K-inflation. The corrections are sensitive to the speed of sound and the choice of string length scale. Moreover the shapes of the corrected non-Gaussianities are distinct from that of ordinary ones.