  The dynamics of star polymers has been investigated via extensive Molecular-
and Brownian Dynamics simulations for a large range of functionality $f$ and
packing fraction $\eta$. The calculated isodiffusivity curves display both
minima and maxima as a function of $\eta$ and minima as a function of $f$.
Simulation results are compared with theoretical predictions based on different
approximations for the structure factor. In particular, the ideal glass
transition line predicted by mode-coupling theory is shown to exactly track the
isodiffusivity curves, offering a theoretical understanding for the observation
of disordered arrested states in star polymer solutions.
