  If the observable universe is a braneworld of Randall-Sundrum type, then
particle interactions at high energies will produce 5-dimensional gravitons
that escape into the bulk. As a result, the Weyl energy density on the brane
does not behave like radiation in the early universe, but does so only later,
in the low energy regime. Recently a simple model was proposed to describe this
modification of the Randall-Sundrum cosmology. We investigate the dynamics of
this model, and find the exact solution of the field equations. We use a
dynamical systems approach to analyze global features of the phase space of
solutions.
