  These are introductory notes on the study of the Dirac equation in curved
spacetime and its relation to hidden symmetries of the dynamics. We present
general results on the relation between special spacetime tensors and hidden
symmetries, both for the full Dirac equation and for its semi-classical limit,
the spinning particle. A concrete application of the general results is
provided by the case of rotating higher dimensional black holes with
cosmological constant, which we discuss. For these metrics the Dirac equation
is separable and the relation between this and hidden symmetries is explained.
