  Fix a simple complex Lie group G and a principal sl(2,C) subalgebra of
Lie(G). Then the moduli space of semi-stable, topologically trivial G-Higgs
bundles on a hyperbolic, spin Riemann surface acquires a marked point. This is
the unique C*-fixed point on the Hitchin section. We describe a universal
analytic family of deformations which provides holomorphic Darboux coordinates
in a neighbourhood of the section. This is a special case of a more general
deformation-theoretic construction in the spirit of Kuranishi theory. As a toy
example of the latter we consider the tautological family of centralisers over
the Kostant slice.
