  We compute the greybody factors for classical black holes in a domain where
two kinds of charges and their anticharges are excited by the extra energy over
extremality. We compare the result to the greybody factors expected from an
effective string model which was earlier shown to give the correct entropy. In
the regime where the left and right moving temperatures are much smaller than
the square root of the effective string tension, we find a non-trivial greybody
factor which agrees with the effective string model. However, if the
temperatures are comparable with the square root of the effective string
tension, the greybody factors agree only at the leading order in energy.
Nevertheless, there are several interesting relations between the two results,
suggesting that a modification of the effective string model might lead to
better agreement.

High Energy Physics - Theory