Charge gravastars in f(T) modified gravity

In the present work, we discus the four dimensional spherically symmetric stellar system in the framework of modified f ( T ) gravity theory with electromagnetic field. The field equations are written for two cases, either T ′ = 0 or f TT = 0 . Next we discuss the charged gravastar model which has three regions: an interior region, a shell region and an exterior region. In the interior region, we find the solutions of all physical quantities like density, pressure, electromagnetic field and the metric coefficients for both cases. For T ′ = 0 , a gravastar cannot form, but it forms only for the case f TT = 0 . In the exterior region, we obtain the exterior solution for the vacuum model. In the shell region, we assume that the interior and exterior regions join together at a certain place, so the intermediate region must be thin shell with the approximation h ( ≡ e - b ) ≪ 1 . In this approximation, we find the analytical solutions. The proper length of the thin shell, the entropy and the energy content inside the thin shell are found and they are directly proportional to the proper thickness of the shell ϵ under the approximation ( ϵ ≪ 1 ). According to the Darmois–Israel formalism, we study the matching between the surfaces of interior and exterior regions of the gravastar. The energy density, pressure, equation of state parameter for the surface and mass of the thin shell are obtained.