Quasinormal modes of stringy black holes

String theory is a promising candidate for a fundamental quantum theory of all interactions including Einstein gravity. Some solutions in string theor y can be interpreted as black holes. Using the semi-analytic method and WKB method, the quasinormal modes (QNMs) of (1 + 1)-dimensional black hole in string theory are studied. The QNMs of (1 + 3)-dimensional black hole in st ring theory are also calculated through numerical approach. The numerical i nvestigation has shown that the late time gravitational oscillation of the black hole under an external perturbation is dominated by certain QNMs. (C) 2001 Published by Elsevier Science B.V.