Emergent Universe as an interaction in the dark sector

TL;DR

This paper proposes a cosmological model where dark matter interacts with variable vacuum energy, leading to an emergent universe scenario compatible with recent observational data and constraints.

Contribution

It introduces a novel dark sector interaction model that results in an emergent universe, supported by observational data constraints.

Findings

Models satisfy Planck bounds on dark energy at recombination

Interaction allows for emergent universe without initial singularity

Constraints from Hubble and supernova data validate the models

Abstract

A cosmological scenario where dark matter interacts with a variable vacuum energy for a spatially flat Friedmann-Robertson-Walker space-time is proposed and analysed to show that with a linear equation of state and a particular interaction in the dark sector it is possible to get a model of an Emergent Universe. In addition, the viability of two particular models is studied by taking into account recent observations. The updated observational Hubble data and the JLA supernovae data are used in order to constraint the cosmological parameters of the models and estimate the amount of dark energy in the radiation era. It is shown that the two models fulfil the severe bounds of $\Omega_{x}(z\simeq 1100)<0.009$ at the $2\sigma$ level of Planck.