English

Abundance for threefolds in positive characteristic when $\nu=2$

Algebraic Geometry 2026-04-20 v3

Abstract

In this paper, we prove the abundance conjecture for threefolds over a perfect field kk of characteristic p>3p > 3 in the case of numerical dimension equals to 22. More precisely, we prove that if (X,B)(X,B) be a projective lc threefold pair over kk such that KX+BK_{X}+B is nef and ν(KX+B)=2\nu(K_{X}+B)=2, then KX+BK_{X}+B is semiample.

Keywords

Cite

@article{arxiv.2307.03938,
  title  = {Abundance for threefolds in positive characteristic when $\nu=2$},
  author = {Zheng Xu},
  journal= {arXiv preprint arXiv:2307.03938},
  year   = {2026}
}

Comments

Final version, to appear in Compositio Mathematica