Stringy quantum effects in two-dimensional black hole

Abstract

We discuss the classical two-dimensional black hole in the framework of the non-perturbative formulation (in terms of non-relativistic fermions) of c=1 string field theory. We identify an off-shell operator whose classical equation of motion is that of tachyon in the classical graviton-dilaton black hole background. The black hole 'singularity' is identified with the Fermi surface in the phase space of a single fermion, and as such is a consequence of the semiclassical approximation. An exact treatment reveals that stringy quantum effects wash away the classical singularity.