Strongly nonnegative curvature
arXiv:1511.07899 · doi:10.1007/s00208-016-1457-3
Abstract
We prove that all currently known examples of manifolds with nonnegative sectional curvature satisfy a stronger condition: their curvature operator can be modified with a 4-form to become positive-semidefinite.
LaTeX2e, 14 pages, revised version (some details given in previous versions are now omitted, following referee's request). To appear in Math. Ann