Geometry/Differential topology
The Euler class of an umbilic foliation
[La class d'Euler d'un feuilletage totalement ombilical]
Comptes Rendus. Mathématique, Tome 354 (2016) no. 6, pp. 614-618.

Étant donné une variété feuilletée munie de formes de courbure convenables, nous calculons explicitement sa classe d'Euler dans le cas totalement ombilical. Si la feuille est compacte, nous obtenons des obstructions topologiques dans le cas où certains groupes d'homologie de la variété feuilletée sont triviaux. Les résultats se généralisent aux distributions tangentes à une sous-variété ombilicale.

Given a foliation on a manifold with suitable curvature form, the Euler class of its tangent bundle is explicitly computed whenever it admits an umbilic leaf. If the leaf is compact, then topological obstructions arise by considering foliated manifolds with certain trivial cohomology group. The results fully generalize to distributions tangent to at least one compact umbilic submanifold.

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Accepté le :
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DOI : 10.1016/j.crma.2016.03.014
Gonçalves, Icaro 1 ; Brito, Fabiano 2

1 Dpto. de Matemática, Instituto de Matemática e Estatística, Universidade de Sāo Paulo, R. do Matāo 1010, Sāo Paulo, SP 05508-900, Brazil
2 Centro de Matemática, Computação e Cognição, Universidade Federal do ABC, 09.210-170 Santo André, Brazil
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Gonçalves, Icaro; Brito, Fabiano. The Euler class of an umbilic foliation. Comptes Rendus. Mathématique, Tome 354 (2016) no. 6, pp. 614-618. doi : 10.1016/j.crma.2016.03.014. http://www.numdam.org/articles/10.1016/j.crma.2016.03.014/

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