A Metric with Positive Sectional Curvature on $S^2\times S^3$

Shengtao Guo, Ethan X. Fang, Junwei Lu

We prove that $S^2\times S^3$ admits a Riemannian metric with positive sectional curvature. We view it as a principal circle bundle over $S^2\times S^2$. A diagonal Cheeger deforma…