Blow-up preservation of positive holomorphic sectional curvature

Determine whether the blow-up along a subvariety of a projective manifold that admits a metric with positive holomorphic sectional curvature still carries a metric with positive holomorphic sectional curvature.

Background

The authors note that Yang proved compact Kähler manifolds with positive holomorphic sectional curvature are projective and rationally connected, resolving much of Yau’s conjecture. What remains is the question of whether positivity of holomorphic sectional curvature is preserved under blowing up along a subvariety.

This is explicitly identified as the remaining open part of Yau’s conjecture at the time of writing.

References

The remaining part of the conjecture, namely, to find metrics with positive holomorphic sectional curvature on the blow up of a projective manifold is still open.

$\hat{H}$-eigenvalues of Hermitian tensors and some applications  (2508.12476 - Chen et al., 17 Aug 2025) in Section 1 (Introduction), following discussion of Yang [Y]