Four-dimensional cohomogeneity one Ricci flow and nonnegative sectional curvature
arXiv:1606.00778
Abstract
We exhibit the first examples of closed 4-manifolds with nonnegative sectional curvature that lose this property when evolved via Ricci flow.
arXiv commentLaTeX2e, 11 pages, 2 figures, final version. To appear in Comm. Anal. Geom