Séminaires : Géométrie et Théorie des Modèles

We consider Pfaffian functions (after Khovanski) defined in a neighbourhood of 0. On the one hand, we investigate how the coefficients of their MacLaurin expansion are determined by the coefficients of the equations. On the other hand, given the MacLaurin expansion of a Pfaffian chain of a given order and degree, we reconstruct explicitly the space of equations it satisfies. Altogether, these leads to an explicit parametric description of the space of monovariate Pfaffian functions stratified by their order and degree. This is a work in progress with Siegfried Van Hille.