A remark on the canonical decomposition of a connection at an irregular singular point
The author gives a short and simple argument for a new proof Malgrange's theorem: If \(\nabla\) is an absolute integrable connection on \(R\equiv Cx_1,x_2, \dots, x_n((y))\), then the Levelt-Turretin decomposition of the \(R\)-relative connection \(\nabla_{\text{rel}}\) after ramification \(y^{1/N}\) is stabilized by \(\nabla\).
scientific article; zbMATH DE number 1868558