  Quantum vacua are constructed for a time-symmetric cosmology describing
closed string tachyon condensation in two-dimensional string theory. Due to the
Euclidean periodicity of the solution, and despite its time dependence, we are
able to construct thermal states at discrete values of the temperature. The
asymptotic thermal Green functions and stress energy tensor are computed and
found to have an intriguing resemblance to those in the Hartle-Hawking vacuum
of a black hole.
