Polytropic spheres with electric charge: compact stars, the Oppenheimer-Volkoff and Buchdahl limits, and quasiblack holes

Understand

We explore a class of compact charged spheres made of a charged perfect fluid with a polytropic equation of state.

• The charge density is chosen to be proportional to the energy density.
• The study is performed by solving the Tolman-Oppenheimer-Volkoff (TOV) equation which describes the hydrostatic equilibrium.
• We show the dependence of the structure of the spheres for several characteristic values of the polytropic exponent and for different values of the charge densities.