  A model kinetic equation is constructed for the transport of a massless Bose
gas. This equation is applied to solution of the boundary value problem for the
transport of radiation in the half-space occupied by a dispersive medium that
is in local thermal equilibrium with the radiation. It is shown that the
difference in temperature between the dispersive medium and the incident
radiation depends substantially on the character of the scattering properties
of the particles of the medium.
