Vanishing of Stiefel-Whitney classes

Stiefel-whitney Classes for Representations of Groups

Associated to a compact Lie group G is the abelian group P(G) of total Stiefel-Whitney classes of representations. In certain cases the rank of P(G) is equal to the number of conjugacy classes of involutions in G. For the symmetric groups Sn, the total Stiefel-Whitney class of the regular representation is highly divisible in P(Sn) and this implies the existence of 'global' Dickson invariants i...

The computation of Stiefel-Whitney classes

L’anneau de cohomologie d’un groupe fini, modulo un nombre premier, peut être calculé à l’aide d’un ordinateur, comme l’a montré Carlson. Ici “calculer” signifie trouver une présentation en termes de générateurs et relations, et seul l’anneau (gradué) sous-jacent est en jeu. Nous proposons une méthode pour déterminer certains éléments de structure supplémentaires: classes de Stiefel-Whitney et ...

Stiefel-whitney Homology Classes of Quasi-regular Cell Complexes

A quasi-regular cell complex is defined and shown to have a reasonable barycentric subdivision. In this setting, Whitney's theorem that the ^-skeleton of the barycentric subdivision of a triangulated n-manifold is dual to the (n /c)th Stiefel-Whitney cohomology class is proven, and applied to projective spaces, lens spaces and surfaces. 1. QR complexes. A (finite) cell structure on a space X is...

On the Stiefel-whitney Classes of a Manifold. Ii

Stiefel-whitney Classes for Coherent Real Analytic Sheaves

We develop Stiefel-Whitney classes for coherent real analytic sheaves and investigate their applications to analytic cycles on real analytic manifolds.