
## 7. Ricci Flow

1. #### Problem 7.1.

Let $M^n$ be a compact manifold with positive isotropic curvature. Does any blow-up limit of the Ricci flow have non-negative curvature operator?
• #### Problem 7.2.

Suppose $G$ acts freely and isometrically on $M$. What kind of flows on $M/G$ are induced by the Ricci flow on $M$?
• #### Problem 7.3.

Can one improve the Hsiang-Kleiner theorem on positively curved $4$-manifolds with symmetry from homeomorphism to diffeomorphism by using the Ricci flow?

Cite this as: AimPL: Manifolds with non-negative sectional curvature, available at http://aimpl.org/nnsectcurvature.