Can High-Velocity Stars Reveal Black Holes in Globular Clusters?

We estimate the number of individual fast-moving stars observable in globular clusters under the assumption that the clusters contain massive central black holes that follow the galactic M BH -σ relationship. We find that radial velocity measurements are unlikely to detect such stars but that proper-motion studies could reveal such stars, if they exist, in the most likely clusters. Thus, Hubble Space Telescope proper-motion studies can test this hypothesis in a few nearby clusters.