We study the semiclassical spectrum of excitations around a long spinning
string in AdS_3. In addition to the usual small fluctuations, we find the
spectrum contains a branch of solitonic excitations of finite energy. We
determine the dispersion relation for these excitations. This has a
relativistic form at low energies but also matches the dispersion relation for
the "hole" of the dual gauge theory spin chain at high energies. The low-energy
behaviour is consistent with the hypothesis that the solitonic excitations
studied here are continuously related to the elementary excitations of the
string.Comment: 17 pages, 1 figure; additional references include