6 papers
Le rang des tissus de Nakai
Jean Paul Dufour, Daniel Lehmann
According to Alain Hénaut, a planar 4-web is called Nakai's web if the cross-ratio of the tangents to the four foliations at each point is constant and if it has no hexagonal 3-sub…
Les isomorphismes infinitésimaux des tissus de codimension 1
Jean-Paul Dufour
We study local ()-webs of codimension 1 on a manifold of dimension We give a complete description of their possible Lie algebras of infinitesimal diffeomorphisms. More pr…
La formule de la trace pour les tissus planaires
Jean Paul Dufour
We give a complete proof of the fact that the trace of the curvature of the connection associated to a planar d-web (d>3) is the sum of the Blaschke curvatures of its sub 3-webs.
Courbure des tissus planaires définis implicitement par une équation différentielle polynomiale en y'. Programmation
Jean-Paul Dufour, Daniel Lehmann
The aim of this paper is mainly, after some theoretical explanations, to provide a program on Maple for computing, whatever be d, the curvature of the planar d-web implicitely defi…
Des séries de tissus ordinaires de rang maximum en toute dimension
Jean-Paul Dufour, Daniel Lehmann
In this paper, we define, from a finite set E of functions, a family of holomorphic webs of codimension one in any dimension . We prove that it is sufficient t…
Calcul explicite de la courbure des tissus calibrés ordinaires
Jean-Paul Dufour, Daniel Lehmann
We present a MAPLE program for the explicit computation of the curvature of calibrated ordinary webs in codimension one in any dimension (recall that all planar webs are calibrated…