LUMINOSITY PROFILES AND CONTRACTION OF RADIATING SPHERES

A seminumeric method by Herrera, Jimenez and Ruggeri is used to study the evolution of general relativistic spheres in the free streaming ra diation approximation, when specific contraction schemes are imposed a nd for particular oscillatory radiation profiles. On one hand, the eme rging radiation is studied for oscillating contracting spheres, on the other, the variation of the boundary surface is analyzed when a pulsa ting profile is provided. We consider three particular equations of st ate previously studied. It is found that the oscillatory frequency of the surface for the equations of state considered coincides with the f requency of the oscillation for the radiation profile.