Alain Salinier
We examine the problem of the complete description of all valuations of a differential polynomial ring built by means of a derivation acting on an ultrametric field. This problem will be shown to be related to the computation of factorizations of linear differential operators. It will be dealt with an approach close to the building of the "Berkovich tree" used in analysis of analytic functions on the p-adic affine line.
LACO (UPRES A 6090 CNRS)
Département de Mathématiques
Faculté des Sciences
123, avenue Albert Thomas
87060 LIMOGES Cedex
FRANCE.