We consider a matrix model description of the 2d string theory whose matter part is given by a time-like linear dilaton CFT. This is equivalent to the c=1 matrix model with a deformed, but very simple fermi surface. Indeed, after a Lorentz transformation, the corresponding 2d spacetime is a conventional linear dilaton background with a time-dependent tachyon field. We show that the tree level scattering amplitudes in the matrix model perfectly agree with those computed in the world-sheet theory. The classical trajectories of fermions correspond to the decaying D-branes in the time-like linear dilaton CFT. We also discuss the ground ring structure. Furthermore, we study the properties of the time-like Liouville theory by applying this matrix model description. We find that its ground ring structure is very similar to that of the minimal string.
Journal of High Energy Physics
- Pub Date:
- December 2004
- Conformal Field Models in String Theory Tachyon Condensation 2D Gravity Matrix Models;
- High Energy Physics - Theory
- 30 pages, harvmac, typos corrected, acknowledgements and comments added(v2), published version (v3)