Nonsingular Rainbow Universes

TL;DR

This paper explores nonsingular cosmological solutions within gravity rainbow theory, utilizing known modified dispersion relations to fix rainbow functions, resulting in exact nonsingular FRW universe models.

Contribution

It introduces a method to fix gravity rainbow functions using established MDRs, leading to exact nonsingular FRW cosmologies, advancing understanding of early universe models.

Findings

Derived exact nonsingular solutions in gravity rainbow cosmology.

Demonstrated the role of specific MDRs in avoiding cosmological singularities.

Provided a framework for constructing nonsingular universe models.

Abstract

In this work, we study FRW cosmologies in the context of gravity rainbow. We discuss the general conditions for having a nonsingular FRW cosmology in gravity rainbow. We propose that gravity rainbow functions can be fixed using two known modified dispersion relation (MDR), which have been proposed in literature. The first MDR was introduced by Amelino-Camelia, et el. in [9] and the second was introduced by Magueijo and Smolin in [24]. Studying these FRW-like cosmologies, after fixing the gravity rainbow functions, leads to nonsingular solutions which can be expressed in exact forms.