English

On the hard Lefschetz theorem for pseudoeffective line bundles

Algebraic Geometry 2020-05-14 v3

Abstract

In this note, we obtain a number of results related to the hard Lefschetz theorem for pseudoeffective line bundles, due to Demailly, Peternell and Schneider. Our first result states that the holomorphic sections produced by the theorem are in fact parallel, when viewed as currents with respect to the singular Chern connection associated with the metric. Our proof is based on a control of the covariant derivative in the approximation process used in the construction of the section. Then we show that we have an isomorphsim between such parallel sections and higher degree cohomology. As an application, we show that the closedness of such sections induces a linear subspace structure on the tangent bundle. Finally, we discuss some questions related to the optimality of the hard Lefschetz theorem.

Keywords

Cite

@article{arxiv.1911.13253,
  title  = {On the hard Lefschetz theorem for pseudoeffective line bundles},
  author = {Xiaojun Wu},
  journal= {arXiv preprint arXiv:1911.13253},
  year   = {2020}
}

Comments

17 pages. arXiv admin note: substantial text overlap with arXiv:1401.5432, arXiv:math/0006205 by other authors

R2 v1 2026-06-23T12:31:22.702Z