Interior Static Stellar Model with Electric Charge as an Oscillator
  A model approach to the description of static stars filled with a charged Pascal perfect fluid within the framework of general relativity is investigated. The metric is written in Bondi's radiation coordinates. The gravitational equations are reduced to a nonlinear oscillator equation after transfomation to a new variable as a function of the radial coordinate. It is shown that in this case exact solutions of the Einstein-Maxwell equations for a concrete energy density distribution law of the charged fluid may be obtained as solution of the harmonic oscillator equation. 
A.M.Baranov
gr-qc math-ph math.MP