| 概要 | The Hurwitz space H means the space of all covers of CP1
with given degree D and simple branching over N points.
It is a non-Galois unramified cover of the moduli space M of
unordered N-tuples in CP1.
We explain the monodromy action of the base on the fiber, in the case D=4.
Equivalently, we find the Galois group of the Galois cover associated to H-->M.
(joint work with Chris Hall) |