  We study two-dimensional string theory on a time-dependent background, whose
worldsheet description consists of Liouville theory at central charge c = 1 and
Liouville theory at central charge c = 25, together with the conformal ghosts.
We compute the tree-level three-point and four-point cosmological wavefunctions
in string perturbation theory. The latter is evaluated numerically by
decomposing the Liouville four-point correlation functions into Virasoro
conformal blocks and three-point function coefficients and integrating over the
moduli space of the four-punctured sphere string diagram. This computation
numerically confirms a surprisingly simple conjectural result for the
four-point wavefunction whose physical interpretation remains to be clarified.
