On construit explicitement trois metriques completes distinctes d'holonomie egale a G 2 , une metrique complete d'holonomie egale a Spin(7) et diverses metriques incompletes d'holonomie exceptionnelle

It is proved that there exist metrics with holonomy G2 and Spin(7), thus settling the remaining cases in Berger's list of possible holonomy groups. We first reformulate the "holonomy H" condition as… Expand

Basic theorems Cartan-Khler theory linear differential systems the characteristic variety prolongation theory applications of commutative algebra and algebraic geometry to the study of exterior… Expand

An endless belt trained between a driving roller and a guiding roller, such e.g. as a wide rubber belt having a flight thereof bearing against and serving to transport photoprinting sheets over a… Expand

A Kahler metric is said to be Bochner-Kahler if its Bochner curvature vanishes. This is a nontrivial condition when the complex dimension of the underlying manifold is at least 2. In this article it… Expand

In "Exterior Differential Systems", the authors present the results of their ongoing development of a theory of the geometry of differential equations, focusing especially on Lagrangians and… Expand