On the coniveau of rationally connected threefolds
Résumé
We prove that the integral cohomology modulo torsion of a rationally connected threefold comes from the integral cohomology of a smooth curve via the cylinder homomorphism associated to a family of 1-cycles. Equivalently, it is of strong coniveau 1. More generally, for a rationally connected manifold X of dimension n, we show that the strong coniveau N n−2 H 2n−3 (X, Z) and coniveau N n−2 H 2n−3 (X, Z) coincide for cohomology modulo torsion.
Domaines
Mathématiques [math]
Origine : Fichiers produits par l'(les) auteur(s)