Nef but Non-Semi-positive Line Bundles on Hopf Manifolds

Xiaojun Wu

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arXiv · 2608.09114

Nef but Non-Semi-positive Line Bundles on Hopf Manifolds

Xiaojun Wu

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Abstract

We give a complete characterization of the nef, effective, pseudo-effective, and semi-positive cones on Hopf manifolds. In particular, by computing the Ueda classes on non-diagonal Hopf surfaces, we show that the invariant elliptic curve is nef but not semi-positive. Via Bott--Chern cohomology calculations, we construct new examples of nef but non-semi-positive line bundles on Hopf manifolds of arbitrary dimension.

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Xiaojun Wu. 2026-08-10. Nef but Non-Semi-positive Line Bundles on Hopf Manifolds. https://arxiv.org/abs/2608.09114

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