Normal forms of holomorphic matrix-valued functions and corresponding forms for singular differential operators (Q1183200)

Normal forms of holomorphic matrix-valued functions \(A(z)\) under different classes of similarity transformations are investigated. The transformers are analytic on a reduced neighbourhood of the origin, say, with at most a pole singularity at the origin. Also the case that the origin is a finite branch-point is investigated. A special role is played by the Arnold normal form.