Some Remarks on Pseudoconcave Manifolds,The usual examples of pseudoconcave manifolds are obtained by removing some closed “pseudoconvex” subsets of a compact projective algebraic variety. Although there are pseudoconcave manifolds that cannot be obtained in this way, it is natural to ask the question when a pseudoconcave manifold can be obtained by this procedure.
Differentiable Closed Embeddings of Banach Manifolds,In this paper a .. is a ..-manifold which is ., and of differentiability class ., .., whose norm is a .-times continuously differentiable function outside 0∈., .≦ ∞. . with that norm is called a ..-Banach space. Mac Alpin [9] and Colojoara [3, 4] proved that every .∞-Hilbert- manifold has a smooth closed split embedding in the Hilbertspace ...
On Invariant Subsets of Hyberbolic Sets,Let .: . be a diffeomorphism and suppose Λ ? . is a . subset of .. What kind of compact invariant sets can lie in Λ? Even for Anosov diffeomorphisms—where Λ = .—little is known about this question. In this note we exploit the theory of stable manifolds to find necessary conditions on invariant subsets of certain kinds of hyperbolic sets.
Semi-Free and Quasi-Free ,, Actions on Homotopy Spheres,An action of S. on a manifold is ., (resp. .), if the action has just two isotropy groups 0 and S. (resp. 0 and Z.). All actions considered here will be assumed smooth, i.e., .. × .→. is a smooth map.
,Sur le groupe des automorphismes d’un arbre,Le but de cet article est l’étude de la structure du groupe des automorphismes d’un arbre, c’est-à-dire d’un graphe connexe sans circuit. Les principaux résultats obtenus sont résumés dans l’énoncé suivant.
Pontrjagin Classes, the Fundamental Group and some Problems of Stable Algebra1,gin classes, based on the discovery of deep connections between characteristic classes and the fundamental group. There are a number of new stable algebraic problems connected with the diffeomorphism problem and Pontrjagin classes of nonsimply connected manifold (especially when π.= . × ? ? ? × .).
Bowel problems — too much or too littlethe holomorphic tangent bundle to . and . is a holomorphic line bundle. We will also drop the non-degeneracy assumption of the zeroes of s, but we treat only the case where s vanishes at isolated points {.}.
發(fā)表于 2025-3-26 22:40:10
