  We consider early time cosmic evolution in string gas cosmology dominated by
open strings attached to D-branes. After reviewing statistical properties of
open strings in D-brane backgrounds, we use dilaton-gravity equations to
determine the string frame fields. Although, there are distinctions in the
Hagedorn regime thermodynamics and dilaton coupling as compared to closed
strings, it seems difficult to avoid Jeans instability and assume thermal
equilibrium simultaneously, which is already a known problem for closed
strings. We also examine characteristics of a possible subsequent large radius
regime in this setup.
