A gravitating light-ball: Stationary states and developing collapse

Abstract

A ball filled with a light-gas is studied in the frame of GR in the spherically symmetric case. Equations of motion suitable for the numerical solution are developed and it is shown that the variables of the gravitational field can be excluded from the equations of motion, thus reducing the gravitational interaction into an equivalent direct interaction of the matter with itself. The stationary states, oscillation modes and instability modes are computed and the processes of decay of unstable states and of collapse are studied.