  We consider the dynamical evolution of a disk of stars orbiting a central
black hole. In particular, we focus on the effect of the stellar mass function
on the evolution of the disk, using both analytic arguments and numerical
simulations. We apply our model to the ring of massive stars at ~0.1pc from the
Galactic Center, assuming that the stars formed in a cold, circular disk, and
find that our model requires the presence of a significant population of
massive (>100Msun) stars in order to explain the the observed eccentricities of
0.2-0.3. Moreover, in order to limit the damping of the heavier stars'
eccentricities, we also require fewer low-mass stars than expected from a
Salpeter mass function, giving strong evidence for a significantly
``top-heavy'' mass function in the rings of stars seen near to the Galactic
Center. We also note that the maximum possible eccentricities attainable from
circular initial conditions at ages of <10Myr are around 0.4-0.5, and suggest
that any rings of stars found with higher eccentricities were probably not
formed from circular disks.
