An $\protect \text{HP}^2$-bundle over $\protect \text{S}^4$ with nontrivial Â-genus

We explain the existence of a smooth $\mathbf{H} P^2$-bundle over $S^4$ whose total space has nontrivial $\hat{A}$-genus. Combined with an argument going back to Hitchin, this answers a question of Schick and implies that the space of Riemannian metrics of positive sectional curvature on a closed ma...

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Príomhchruthaitheoirí: Krannich, Manuel, Kupers, Alexander, Randal-Williams, Oscar
Formáid: Alt
Teanga:English
Foilsithe / Cruthaithe: Académie des sciences 2021-03-01
Sraith:Comptes Rendus. Mathématique
Rochtain ar líne:https://comptes-rendus.academie-sciences.fr/mathematique/articles/10.5802/crmath.156/