Abstract:
Since the last decade, the expansion of the universe has been a major issue of debate. Itwasrecentlydebatedundertopicslikeastheradiationera(early-time expansion), also known as the inflationary (rapid expansion) era, and the latetime cosmic expansion (dark energy) period. In this thesis, we concentrate on the study of anisotropic stars with anisotropic matter distribution in the framework of f(T,T) = αT(r)2 + βT(r) model, here α, β are represent the arbitrary constants, T andT represent, trace of stress energy-momentum tensor and torsion scalar, respectively. This model has interesting cosmological properties, in addition to providing an effective dark energy sector explanation [13]. In order to attain our target, we considered the Krori-Barua space-time and utilize the off-diagonal tetrad components for deriving the corresponding set of field equations. We evaluate the effective density (ρeff), effective radial (peff r ) and tangential pressure (peff t ) using the EoS of strange star i.e., MIT bag model pr(r) = 1 3[ρ(r) − 4Bg]. In chapter IV we explored anisotropic strange stars by applying karmarker condition without MIT bag model in the background of "f(T,T)"gravity and for the unknown constants aries in the solution have been evaluated by using the conventional matching of interior and exterior space time. Now for checking the feasibility of our model we discuss the anisotropy, energy condition, TOV forces, abreu condition, EoS parameters, adiabatic index, mass function, compactness and redshift for different compact stars models namely, PSRJ1416 − 2230, 4U1608 − 52, CenX − 3, EXO1785 − 248 and SMCX −1.