Jc. Hurtubise et M. Kjiri, Separating coordinates for the generalized Hitchin systems and the classical r-matrices, COMM MATH P, 210(2), 2000, pp. 521-540
We exhibit natural Darboux coordinates for the generalized Hitchin systems
studied by Bottacin and Markman. These systems are defined on spaces of sta
ble pairs consisting of a vector bundle and a form-valued meromorphic endom
orphism of the bundle. In special cases (genus zero, genus one), the bundle
s are:rigid and one has the rational, trigonometric and elliptic Gaudin sys
tems. Explicit formulae are given in these cases.