Anisotropic models with two fluids in linear and quadratic forms of f(T) gravitational theories
© 2015, Springer Science+Business Media Dordrecht. Recent astronomical observations show that the universe may be anisotropic on large scales. The Union2 SnIa data hint that the universe has a preferred direction. If such a cosmological privileged axis indeed exists, one has to consider an anisotropic expanding universe, instead of the isotropic cosmological model. In this study, we apply the field equations of quadratic form of the modified teleparallel gravitational theories, f(T)=T+ϵT2, to anisotropic model. We assume two fluid components, the matter components have two equation of states (EoS). We study different equation of states for the linear case and show that there is no recombination era between the two fluids. For the quadratic one, we assume two equations of state corresponding to dark matter. In this model we obtain an inflation model and show that the values of the parameter, in the early universe, ϵ are depend on the sign of the cosmological constant.
Nashed, Gamal G.L., "Anisotropic models with two fluids in linear and quadratic forms of f(T) gravitational theories" (2015). Centre for Theoretical Physics. 91.