Radiation from a class of string theoretic black holes

The emission of a scalar with low energy $\omega$, from a $D$- $(4\mathrm{}<~D<~8)$ 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 $c_{\mathrm{eff}}=6\mathrm{}$ for any $D$. When the next order in $\omega$ is considered, however, there is no agreement between the two schemes unless $D=5\mathrm{}$, $n=3\mathrm{}$ or $D=4\mathrm{}$, $n=4\mathrm{}$.