Browse › Algebraic and complex geometry › 034 Log abundance for compact Kähler spaces under logarithmic Iitaka subadditivity
Fourfold nonvanishing by minimal metrics and moving jets
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Abstract
We prove canonical nonvanishing for smooth connected projective complex fourfolds: if KX is pseudo-effective, then $H^0(X,mK_X)\ne0$ for some positive integer m.
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Related prior literature mentioned by others
- Jihao Liu and Zheng Xu, Non-vanishing implies numerical dimension one abundance (arXiv:2505.05250v2, July 30, 2025). Highlighted in the family exposition as prior abundance with nonnegative Kodaira dimension and numerical dimension at most one through dimension five, providing a restricted comparison for this manuscript’s broader claim. [family-level]
Possibly relevant literature (found by the agent, not checked)
- Vladimir Lazić, Metrics with minimal singularities and the Abundance conjecture (arXiv:2406.18233, June 2024). Relates abundance for minimal klt pairs to multiplier ideals of currents with minimal singularities, which is related to this paper's use of minimal metrics in proving canonical nonvanishing for fourfolds.
Digests and expositions
- AI Proved What?, Always semiample? (Episode 034, October 2026). Explains the family’s abundance claims, proof strategy, and dependencies. [AI-generated per source] [family-level]
Elsewhere
- Emergent Mind: family 034
Independent sites; their content is not reviewed here.
Cite
@misc{OAI:Fourfold-nonvanishing-by-minimal-metrics-and-moving-jets-September-27-2026,
author = {{OpenAI}},
title = {{Fourfold nonvanishing by minimal metrics and moving jets}},
howpublished = {OpenAI Math Release preprint
\href{https://github.com/openai/math/blob/main/preprints/Fourfold-nonvanishing-by-minimal-metrics-and-moving-jets-September-27-2026/paper.pdf}{OAI:Fourfold-nonvanishing-by-minimal-metrics-and-moving-jets-September-27-2026}},
year = {2026}
}Family 034: Log abundance for compact Kähler spaces under logarithmic Iitaka subadditivity
Using logarithmic Iitaka subadditivity, proves log abundance in every dimension for normal compact Kähler log canonical pairs with effective rational boundary: an analytically nef ℚ-Cartier adjoint is semiample. It also proves projective log abundance over every algebraically closed field of characteristic zero and the effective Iitaka fibration conjecture for smooth projective varieties of nonnegative Kodaira dimension in that setting. A further result resolves the finite-rational-coefficient index conjecture for connected projective semi-log-canonical log Calabi–Yau pairs over such fields in each fixed dimension and for each fixed finite set of rational boundary coefficients, with a uniform index independent of the number of components.
Other papers in this family:
- Log abundance for compact Kähler spaces under logarithmic Iitaka subadditivity · October 6, 2026
- Uniform indices for semi-log-canonical log Calabi–Yau pairs · October 5, 2026
- Conditional good minimal models for compact Kähler fourfolds · October 6, 2026
- Log abundance in characteristic zero · September 24, 2026
- Minimal metrics and interior injectivity for nef adjoints · September 27, 2026
- Lifting sections from the reduced support of an adjoint · September 27, 2026
- Schnell fiber spaces and good canonical models · September 24, 2026
- Uniform log Iitaka fibrations and bounded moduli denominators · October 4, 2026
- Uniform Pluricanonical Iitaka Fibrations · October 3, 2026
- Relative denominators and effective systems for log Calabi-Yau fibrations · September 27, 2026
- Arithmetic Stein-degree bounds for log Calabi–Yau pairs · September 25, 2026
- Uniform effective log Iitaka fibrations for fourfolds · September 26, 2026
- Abundance after nonvanishing for compact Kähler fourfolds · September 27, 2026