The Signature of Quasi-Nilpotent Fiber Bundles
This paper belongs to a series of papers devoted to the study of the cohomology of classifying spaces. Generalizing the Weil algebra of a Lie algebra and Kalkman’s BRST model, here we introduce the Weil algebra associated to any Lie algebroid . We then show that this Weil algebra is related to the Bott-Shulman complex (computing the cohomology of the classifying space) via a Van Est map and we prove a Van Est isomorphism theorem. As application, we generalize and find a simpler more conceptual...
Soit un -fibré principal différentiable sur une variété ( un groupe de Lie compact). Étant donné une action d’un groupe de Lie compact sur , on se pose la question de savoir si elle provient d’une action sur le fibré . L’originalité de ce travail est de relier ce problème à l’existence de points fixes pour les actions de que l’on induit naturellement sur divers espaces de modules de -connexions sur .
We are interested in a topological realization of a family of pseudoreflection groups ; i.e. we are looking for topological spaces whose mod-p cohomology is isomorphic to the ring of invariants . Spaces of this type give partial answers to a problem of Steenrod, namely which polynomial algebras over can appear as the mod-p cohomology of a space. The family under consideration is given by pseudoreflection groups which are subgroups of the wreath product where q divides p - 1 and where p is...