Enhanced CMBR non-Gaussianities from Lorentz violation

TL;DR

This paper investigates how Lorentz symmetry violation can enhance non-Gaussian features in the cosmic microwave background radiation bispectrum, revealing potential observable signatures of high-energy physics beyond standard models.

Contribution

It provides a quantitative analysis of the impact of Lorentz violation on the CMBR bispectrum, highlighting distinct patterns and potential for experimental detection.

Findings

Enhanced bispectrum configurations identified

Distinct oscillation patterns depending on dispersion relation

Potential for experimental tests of Lorentz violation

Abstract

We study the effects of Lorentz symmetry violation on the scalar CMBR bispectrum. Our quantitative results show that there can be enhancements in the bispectrum for specific configurations in momentum space, when the modified dispersion relations resulting from the symmetry breaking violate the adiabatic condition for a short period of time in the early Universe. The kind of configurations that are enhanced and the pattern of oscillations in wavenumbers that generically appear in the bispectrum strictly depend on the form of the modified dispersion relation, and therefore on the pattern of Lorentz violation. These effects are found to be distinct from those that appear when modelling very high-energy (transplanckian) physics via modified boundary conditions (modified vacuum). In fact, under certain conditions, the enhancements are even stronger, and possibly open a door to the experimental study of Lorentz violation through these phenomena.