Non-Gaussianity Generated by the Entropic Mechanism in Bouncing Cosmologies Made Simple

TL;DR

This paper introduces a simple analytic method to approximate non-Gaussianity parameters in cyclic cosmological models with entropic perturbation generation, simplifying complex calculations and aligning well with numerical results.

Contribution

It provides a quick, transparent analytic approach for calculating non-linearity parameters in entropic mechanism-based bouncing cosmologies, improving understanding and efficiency.

Findings

Analytic approximation matches numerical results well

Method simplifies complex second and third order perturbation calculations

Enhances understanding of non-Gaussianity in early universe models

Abstract

Non-gaussianity in the microwave background radiation is bound to play a key role in giving us clues about the physics of the very early universe. However, the associated calculations, at second and even third order in perturbation theory, tend to be complicated to the point of obscuring simple underlying physical processes. In this note, we present a simple analytic procedure for approximating the non-linearity parameters f_{NL} and g_{NL} for cyclic models in which the cosmological perturbations are generated via the entropic mechanism. Our approach is quick, physically transparent and agrees well with the results of numerical calculations.