Ganea and Whitehead definitions for the tangential Lusternik-Schnirelmann category of foliations

This work solves the problem of elaborating Ganea and Whitehead definitions for the tangential category of a foliated manifold. We develop these two notions in the category \Tops of stratified spaces, that are topological spaces $X$ endowed with a partition \cF and compare them to a third invariant defined by using open sets. More precisely, these definitions apply to an element (X,\cF) of \Tops together with a class \cA of subsets of $X$; they are similar to invariants introduced by M. Clapp and D. Puppe. If (X,\cF)\in\Tops, we define a transverse subset as a subspace $A$ of $X$ such that the intersection $S\cap A$ is at most countable for any S\in \cF. Then we define the Whitehead and Ganea LS-categories of the stratified space by taking the infimum along the transverse subsets. When we have a closed manifold, endowed with a $C^1$-foliation, the three previous definitions, with \cA the class of transverse subsets, coincide with the tangential category and are homotopical invariants.Comment: 14 pages, 2 figure

LS-catégorie dans une catégorie à modèles

Doctorat en Sciences mathématiques -- UCL, 199

Logique modale propositionnelle et pr dicative (s mantique de cat gories)

SIGLEBSE B224456T / UCL - Université Catholique de LouvainBEBelgiu