Low-dimensional manifolds with non-negative curvature and maximal symmetry rank

Fernando Galaz-Garcia, Catherine Searle
2010 Proceedings of the American Mathematical Society  
We classify closed, simply connected n-manifolds of non-negative sectional curvature admitting an isometric torus action of maximal symmetry rank in dimensions 2 ≤ n ≤ 6. In dimensions 3k, k = 1, 2 there is only one such manifold and it is diffeomorphic to the product of k copies of the 3-sphere.
doi:10.1090/s0002-9939-2010-10655-x fatcat:o4otp5hbdfczrmojwqbymbnzee