Type: Article
Publication Date: 2013-04-08
Citations: 15
DOI: https://doi.org/10.2140/gt.2013.17.563
The Hopf conjecture states that an even-dimensional, positively curved Riemannian manifold has positive Euler characteristic. We prove this conjecture under the additional assumption that a torus acts by isometries and has dimension bounded from below by a logarithmic function of the manifold dimension. The main new tool is the action of the Steenrod algebra on cohomology.