Thesis (M.Sc.)--Chulalongkorn University, 2015

If we consider a solution of the Einstein field equations for a static sphere, the solution can be written in terms of the metric or mass (energy). For the metric form, geometric properties of the sphere are explicit. On the other hand, the pressure and the density present clear explanations about the internal structure of an object. In this thesis, charged fluid spheres are of interest and considered in both the metric and mass (energy) form. The charged fluid sphere is a result of a modified perfect fluid sphere model by adding the electromagnetic field and scalar field. One particular feature of charged fluid sphere is the anisotropy of pressure, where the radial pressure and the transverse pressure are not equal. A construction of the solution generating theorems of charged fluid sphere is presented in the thesis. This technique can be used to generate new solutions from known solutions without having to solve the Einstein field equations directly. In the view of spacetime, the generating theorems for metric solutions are created in Schwarzschild coordinates. The theorems are then tested with the Tolman-Bayin metric. For the interior solution, the modified Tolman-Oppenheimer-Volkov (TOV) equation brings about the initial solution of the generating theorems in terms of pressure and density. Moreover, the effects of electric charge density on fluid pressure are also considered as a special case.