  We use group cohomology and the de Rham complex on simplicial manifolds to
give explicit differential forms representing generators of the cohomology
rings of moduli spaces of representations of fundamental groups of 2-manifolds.
These generators are constructed using the de Rham representatives for the
cohomology of classifying spaces $BK$ where $K$ is a compact Lie group; such
representatives (universal characteristic classes) were found by Bott and
Shulman. Thus our representatives for the generators of the cohomology of
moduli spaces are given explicitly in terms of the Maurer-Cartan form. This
work solves a problem posed by Weinstein, who gave a corresponding construction
(following Karshon and Goldman) of the symplectic forms on these moduli spaces.
We also give a corresponding construction of equivariant differential forms on
the extended moduli space $X$, which is a finite dimensional symplectic space
equipped with a Hamiltonian action of $K$ for which the symplectic reduced
space is the moduli space of representations of the 2-manifold fundamental
group in $K$. (This paper is in press in Duke Math. J. The substance of the
text is unaltered; inor changes and corrections have been made to the file to
correspond to the version that will be published.)
