Cosmological Implications of the Generalized Entropy Based Holographic Dark Energy Models in Dynamical Chern-Simons Modified Gravity

M Younas,H Moradpour,Saba Qummer,Shamaila Rani,Abdul Jawad

doi:10.1155/2019/1287932

Abstract

Recently, Tsallis, Rényi, and Sharma-Mittal entropies have widely been used to study the gravitational and cosmological setups. We consider a flat FRW universe with linear interaction between dark energy and dark matter. We discuss the dark energy models using Tsallis, Rényi, and Sharma-Mittal entropies in the framework of Chern-Simons modified gravity. We explore various cosmological parameters (equation of state parameter, squared sound of speed ) and cosmological plane (ωd-ωd′, where ωd′ is the evolutionary equation of state parameter). It is observed that the equation of state parameter gives quintessence-like nature of the universe in most of the cases. Also, the squared speed of sound shows stability of Tsallis and Rényi dark energy model but unstable behavior for Sharma-Mittal dark energy model. The ωd-ωd′ plane represents the thawing region for all dark energy models.

Highlights

In the last few years, remarkable progress has been achieved in the understanding of the universe expansion
We investigate the different cosmological parameters such as equation of state parameter and the cosmological ωd − ωd󸀠 plane where ωd󸀠 shows the evaluation with respect to ln a
We have taken the flat FRW universe, and linear interaction term is chosen for the interacting scenario between dark energy (DE) and dark matter

Summary

Introduction

In the last few years, remarkable progress has been achieved in the understanding of the universe expansion. The dark matter constitutes about 25% of the total energy density of the universe. A second approach for understanding this strange component of the universe is modifying the standard theories of gravity, namely, general relativity (GR). Cosmological consequences of some HDE models in the dynamical ChernSimons framework, as a modified gravity theory, can be found in [23]. We use the Tsallis, SharmaMittal, and Renyi entropies in the framework of dynamical Chern-Simons modified gravity and consider an interaction term.

Dynamical Chern-Simons Modified Gravity

Tsallis Holographic Dark Energy

Rényi Holographic Dark Energy Model

Sharma-Mittal Holographic Dark Energy Model

Findings

Conclusion