Radiation from a class of string theoretic black holes

The emission of a scaler with low energy omega, from a D- (4 less than or equal to D less than or equal to 8) dimensional black hole with n charges, is studied in both string and semiclassical calculations. In the lowest order in omega, the weak coupling string and semiclassical calculations agree provided that the Bekenstein-Hawking formula is valid and the effective central charge c(eff)=6 for any D. When the next order in omega is considered, however, there is no agreement between the two schemes unless D=5, n=3 or D=4, n=4.