Signatures of Planck-scale interactions in the cosmic microwave background?

TL;DR

This paper investigates potential signatures of Planck-scale physics, like quantum gravity, in the cosmic microwave background anisotropies, focusing on non-Gaussian features such as the three-point function to distinguish different models.

Contribution

It provides a general framework to calculate possible Planck-scale effects on CMB anisotropies, emphasizing non-Gaussian signatures and their role in testing quantum gravity models.

Findings

Planck-scale interactions induce non-Gaussianities in the CMB.

The three-point function can discriminate between Lorentz-invariant and violating models.

Potential observational signatures of quantum gravity effects are identified.

Abstract

Based on a rather general low-energy effective action (interacting quantum fields in classical curved space-times), we calculate potential signatures of new physics (such as quantum gravity) at ultra-high energies (presumably the Planck scale) in the anisotropies of the cosmic microwave background. These Planck-scale interactions create non-Gaussian contributions, where special emphasis is laid on the three-point function as the most promising observable, which also allows the discrimination between models violating and those obeying Lorentz invariance. PACS: 98.80.Cq, 04.62.+v, 98.70.Vc, 98.80.Qc.