  We study an effective four-dimensional theory with an action with two scalar
fields minimally coupled to gravity, and with a matter action which couples to
the two scalar fields via an overall field-dependent coefficient in the action.
Such a theory could arise from a dimensional reduction of supergravity coupled
to a gas of branes winding the compactified dimensions. We show the existence
of solutions corresponding to power-law inflation. The graceful exit from
inflation can be obtained by postulating the decay of the branes, as would
occur if the branes are unstable in the vacuum and stabilized at high densities
by plasma effects. This construction provides an avenue for connecting string
gas cosmology and the late-time universe.
