On the possibility of a box for holding gravitational radiation in thermal equilibrium

Abstract

We show that it is possible in principle to build a box which will hold gravitational radiation for a time long enough to thermalize it. The box is a thin spherical shell of charged matter with a large red shift at the surface of the shell. The radiation is kept in the box by the gravitational potential of the shell and is thermalized by the conversion between gravitational and electromagnetic radiation. We calculate the time for escape of the radiation and show that it is longer than the conversion time.