Intermediate-degree cohomology bound without curvature regularity

Determine whether, for every compact complex manifold X of dimension n≥3, every smooth Hermitian holomorphic line bundle (L,h) whose curvature has maximal rank 1≤r<n, and every fixed holomorphic vector bundle E, the intermediate Dolbeault cohomology dimensions satisfy h^q(X,L^p⊗E)=O(p^r) for all 1≤q≤n−1, without assuming positivity, constant curvature rank, or a regular foliation in the curvature kernel.

Background

The paper proves the bound hq(X,Lp⊗E)=O_ε(p{r+ε}) for every ε>0 and obtains the sharper O(pr) estimate in degrees q=0 and q=n. It also establishes the O(pr) bound in every degree on compact complex surfaces. The unresolved issue concerns intermediate degrees in dimensions at least three.

Bouche’s earlier result gives the desired O(pr) estimate under the additional hypothesis that the curvature kernel contains the tangent bundle of a regular holomorphic foliation. The question asks whether that geometric hypothesis, as well as positivity and constant-rank assumptions, can be removed entirely. The paper’s fixed-depth rescaling argument does not resolve this endpoint exponent because its constants are not uniform as the number of rescaling steps tends to infinity.

References

The remaining question is:

Let $X$ be a compact complex manifold of dimension $n\ge3$, let $(L,h)$ have smooth curvature of maximal rank $1\le r<n$, and let $E$ be a fixed holomorphic vector bundle. Must

hq(X,Lp\otimes E)=O(pr)\qquad(1\le q\le n-1)

hold without positivity, constant rank, or a regular foliation in the curvature kernel?

— Dolbeault Cohomology Growth under Curvature Rank Bounds  (2610.09295 - Qin, 7 Oct 2026) in Section 6, “The intermediate degrees,” Question 6.1 (labelled half:question:full-corank)