Emergent Universe With Exotic Matter In Loop Quantum Cosmology, DGP Brane World and Kaluza-Klein Cosmology

TL;DR

This paper explores emergent universe scenarios across various cosmological models, revealing conditions under which the universe can emerge without a big bang, with findings specific to scalar and tachyonic fields in each model.

Contribution

It provides a comparative analysis of emergent universe scenarios in Loop quantum cosmology, DGP brane, and Kaluza-Klein models, highlighting new conditions for their realization.

Findings

Emergent scenario in Loop quantum cosmology depends on matter density conditions.

DGP brane model allows almost unconditional emergent scenarios for scalar fields.

Kaluza-Klein cosmology supports emergent universe only in closed universe with scalar fields.

Abstract

In this work we have investigated the emergent scenario of the universe described by Loop quantum cosmology model, DGP brane model and Kaluza-Klein cosmology. Scalar field along with barotropic fluid as normal matter is considered as the matter content of the universe. In Loop quantum cosmology it is found that the emergent scenario is realized with the imposition of some conditions on the value of the density of normal matter in case of normal and phantom scalar field. This is a surprising result indeed considering the fact that scalar field is the dominating matter component. In case of Tachyonic field, emergent scenario is realized with some constraints on the value of $\rho_{1}$ for both normal and phantom tachyon. In case of DGP brane-world realization of an emergent scenario is possible almost unconditionally for normal and phantom fields. Plots and table have been generated to testify this fact. In case of tachyonic field emergent scenario is realized with some constraints on $\dot{H}$. In Kaluza-Klein cosmology emergent scenario is possible only for a closed universe in case of normal and phantom scalar field. For a tachyonic field realization of emergent universe is possible for all models(closed, open and flat).