An exotic sphere with positive sectional curvature
arXiv:0805.0812
Abstract
We show that there is a metric on the Gromoll-Meyer sphere with positive sectional curvature.
A referee discovered an error in the statement of Theorem 5.3. This error is corrected and the result is renamed, Lemma 5.3. A coarse outline has been added at the end of the introduction. 95 pages