V. Cocco et al., ON THE ENERGY EXTRACTION FROM THE INTERIOR SCHWARTZSCHILD METRIC, Nuovo cimento della Societa italiana di fisica. B, Relativity, classical and statistical physics, 110(1), 1995, pp. 95-100
The binding energies of stable circular orbits within an internal Schw
artzschild solution are investigated. It is shown how, under suitable
circumstances, the binding energy may be equal to the total rest mass
energy of a test particle.