A DEFORMED MATRIX MODEL AND THE BLACK-HOLE BACKGROUND IN 2-DIMENSIONAL STRING THEORY

We investigate how the exact two-dimensional black-hole solution for the critical string theory should be described, at least perturbatively with respect to the inverse mass of the black hole, within the framework of matrix model. In particular, we propose a working hypothesis on the basis of which we can present plausible candidates for the necessary non-local field redefinition of the tachyon field and the deformation of the usual c = 1 matrix model with mu = 0. We exhibit some marked difference in the proper-ties of tachyon scattering of the deformed model from those of the usual c = 1 model corresponding to tachyon condensation. These results lead to a concrete proposal for the S-matrix for the tachyon black-hole scattering.