On the horizontal gauge cohomology and non-removability of the spectral parameter

by M. Marvan

Acta Appl. Math. 72 (2002) 51–65.
Preprint DIPS

Given a 1-parametric family of zero-curvature representations a(l), the first horizontal gauge cohomology group is shown to contain obstructions to removability of the parameter l. A method to compute the group is suggested.