Observational constraint on interacting Tsallis holographic dark energy in logarithmic Brans\u2013Dicke theory

Y Aditya,P K Sahoo,Sanjay Mandal,D R K Reddy

doi:10.1140/epjc/s10052-019-7534-5

Abstract

In this paper, we investigate the dark energy phenomenon by studying the Tsallis holographic dark energy within the framework of Brans–Dicke (BD) scalar–tensor theory of gravity (Brans and Dicke in Phys. Rev. 124:925, 1961). In this context, we choose the BD scalar field phi as a logarithmic function of the average scale factor a(t) and Hubble horizon as the IR cutoff (L=H^{-1}). We reconstruct two cases of non-interacting and interacting fluid (dark sectors of cosmos) scenario. The physical behavior of the models are discussed with the help of graphical representation to explore the accelerated expansion of the universe. Moreover, the stability of the models are checked through squared sound speed v_s^2. The well-known cosmological plane i.e., omega _{de}-omega ^{prime }_{de} is constructed for our models. We also include comparison of our findings of these dynamical parameters with observational constraints. It is also quite interesting to mention here that the results of deceleration, equation of state parameters and omega _{de}-omega ^{prime }_{de} plane coincide with the modern observational data.

Highlights

The holographic dark energy (DE) (HDE) model [48] has been suggested in the context of quantum gravity with the help of holographic principle [49]
The new holographic DE (HDE) model can obtain the accelerated expansion of the universe and showed that the transition redshift from deceleration phase (q > 0) to acceleration phase (q < 0) is consistent with current observational data [51,52]
Some new HDE models are constructed such as Tsallis HDE (THDE) [60,61], Renyi HDE model (RHDE) [62] and Sharma-Mittal HDE (SMHDE) [63]

Summary

Introduction

The holographic DE (HDE) model [48] has been suggested in the context of quantum gravity with the help of holographic principle [49]. With this motivation, in this work we consider the HDE with another entropy formalism i.e., Tsallis HDE As mentioned above, another approach to explore the present accelerated expansion of the universe is the modified theories of gravity. Ghaffari et al [87] have discussed interacting and non-interacting THDE models by considering the Hubble horizon as the IR cutoff within BD scalar theory framework, while Jawad et al [88] have studied cosmological implications of THDE in modified version of BD scalar theory In both the models the authors have considered the BD scalar field φ as a power function of average scale factor a(t). We are interested in studying the both noninteracting and interacting Tsallis holographic dark energy in Brans–Dicke scalar–tensor theory by considering homogeneous, isotropic FRW flat universe.

Tsallis holographic dark energy in BD theory

Non-interacting model

Interacting model

Conclusions