Let h C P 3 h CP³ denote a 6 6 -dimensional smooth manifold that is homotopy equivalent to the complex 3 3 -dimensional projective space C P 3 CP³. In this paper, we prove that if the first Pontrjagin class of h C P 3 h CP³ satisfies p 1 (h C P 3) ≥ 4 p₁ (h CP³) 4, then the product manifold h C P 3 × S 7 h CP³ S⁷ admits a Riemannian metric with non-negative sectional curvature. This conclusion follows from the diffeomorphism property: h C P 3 × S 7 h CP³ S⁷ is diffeomorphic to a certain manifold which admits a Riemannian metric with non-negative sectional curvature.
Wen Shen (Thu,) studied this question.