Barrow Holographic Dark Energy in Extended Teleparallel Theories of Gravity

Abstract

In this thesis, we reconstruct some solutions in the context of telepar- allel based extended theories coupled with trace of energy-momentum ten- sor, boundary term and Gauss-Bonnet term. For this purpose, we ob- tain the effective energy density and pressure for these theories for flat FRW universe model. The reconstruction is made through the compari- son of these effective energy densities with the energy density of Barrow holographic dark energy model. In this regards, we use scale factor in terms of power-law form and find some gravitational Lagrangian functions as f(T ) = T +g(T ), f(T, τ ) = T +γh(τ ), f (T, τ ) = βτ +g(T ), f(T, TG) = TGg(T ), f(T, TG) = −T + TGg(T ), f(T, TG) = TG + g(T ), f(T, TG) = T + j(TG), f(T, B) = T + σy(B) and f(T, B) = B + ξg(T ). In order to discuss the cosmic analysis related to these models, we plot equation of state parameter for each model. We investigate the squared speed of sound parameter for these models to determine the stability of the models. We obtain some favorable results related to specific values of model parameters.